The expression of gill Na, K-ATPase in milkfish, Chanos chanos, acclimated to seawater, brackish water and fresh water.

PubMed

Lin, Y M; Chen, C N; Lee, T H

2003-07-01

Juvenile milkfish Chanos chanos (Forsskål, 1775) were transferred from a local fish farm to fresh water (FW; 0 per thousand ), brackish water (BW; 10 per thousand, 20 per thousand ) and seawater (SW; 35 per thousand ) conditions in the laboratory and reared for at least two weeks. The blood and gill of the fish adapted to various salinities were analyzed to determine the osmoregulatory ability of this euryhaline species. No significant difference was found in plasma osmolality, sodium or chloride concentrations of milkfish adapted to various salinities. In FW, the fish exhibited the highest specific activity of Na, K-ATPase (NKA) in gills, while the SW group was found to have the lowest. Relative abundance of branchial NKA alpha-subunit revealed similar profiles. However, in contrary to other euryhaline teleosts, i.e. tilapia, salmon and eel, the naturally SW-dwelling milkfish expresses higher activity of NKA in BW and FW. Immunocytochemical staining has shown that most Na, K-ATPase immunoreactive (NKIR) cells in fish adapted to BW and SW were localized to the filaments with very few on the lamellae. Moreover, in FW-adapted milkfish, the number of NKIR cells found on the lamellae increased significantly. Such responses as elevated NKIR cell number and NKA activity are thought to improve the osmoregulatory capacity of the milkfish in hyposaline environments.

Freshwater to seawater transitions in migratory fishes

USGS Publications Warehouse

Zydlewski, Joseph D.; Michael P. Wilkie,

2012-01-01

The transition from freshwater to seawater is integral to the life history of many fishes. Diverse migratory fishes express anadromous, catadromous, and amphidromous life histories, while others make incomplete transits between freshwater and seawater. The physiological mechanisms of osmoregulation are widely conserved among phylogenetically diverse species. Diadromous fishes moving between freshwater and seawater develop osmoregulatory mechanisms for different environmental salinities. Freshwater to seawater transition involves hormonally mediated changes in gill ionocytes and the transport proteins associated with hypoosmoregulation, increased seawater ingestion and water absorption in the intestine, and reduced urinary water losses. Fishes attain salinity tolerance through early development, gradual acclimation, or environmentally or developmentally cued adaptations. This chapter describes adaptations in diverse taxa and the effects of salinity on growth. Identifying common strategies in diadromous fishes moving between freshwater and seawater will reveal the ecological and physiological basis for maintaining homeostasis in different salinities, and inform efforts to conserve and manage migratory euryhaline fishes.

Osmoregulatory actions of the GH/IGF axis in non-salmonid teleosts

USGS Publications Warehouse

Mancera, J.M.; McCormick, S.D.

1998-01-01

Salmonid fishes provided the first findings on the influence of the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis on osmoregulation in teleost fishes. Recent studies on non-salmonid species, however, indicate that this physiological action of the GH/IGF-I axis is not restricted to salmonids or anadromous fishes. GH-producing cells in the pituitary of fish acclimated to different salinities show different degrees of activation depending on the species studied. Plasma GH levels either increase or do not change after transfer of fish from freshwater to seawater. Treatment with GH or IGF-I increases salinity tolerance and/or increases gill Na+,K+-ATPase activity of killifish (Fundulus heteroclitus), tilapia (Oreochromis mossambicus and Oreochromisniloticus) and striped bass (Morone saxatilis). As in salmonids, a positive interaction between GH and cortisol for improving hypoosmoregulatory capacity has been described in tilapia (O. mossambicus). Research on the osmoregulatory role of the GH/IGF-I axis is derived from a small number of teleost species. The study of more species with different osmoregulary patterns will be necessary to fully clarify the osmoregulatory role of GH/IGF-I axis in fish. The available data does suggest, however, that the influence of the GH/IGF-I axis on osmoregulation may be a common feature of euryhalinity in teleosts.

Metazoan parasites of fishes from the Celestun coastal lagoon, Yucatan, Mexico.

PubMed

Sosa-Medina, Trinidad; Vidal-Martínez, Víctor M; Aguirre-Macedo, M Leopoldina

2015-08-31

The aims of this study were to produce a checklist of the metazoan parasites of fishes from the Celestun coastal lagoon and to determine the degree of faunal similarity among the fishes based on the metazoan parasites they share. A checklist was prepared including all available records (1996-2014) of parasites of marine, brackish water and freshwater fishes of the area. All of these data were included in a presence/absence database and used to determine similarity via Jaccard's index. The results indicate the presence of 62 metazoan parasite species infecting 22 fish species. The number of metazoan parasite species found in the fishes from the Celestún lagoon is apparently the highest reported worldwide for a tropical coastal lagoon. The parasites included 12 species of adult digeneans, 27 digeneans in the metacercarial stage, 6 monogeneans, 3 metacestodes, 9 nematodes, 2 acanthocephalans, 2 crustaceans and 1 annelid. Forty parasite species were autogenic and 23 were allogenic and 1 unknown. The overall similarity among all of the species of fish with respect to the metazoan parasites they share was low (0.08 ± 0.12), with few similarity values above 0.4 being obtained. This low similarity was due primarily to the presence of suites of parasites exclusive to specific species of fish. The autogenic component of the parasite fauna (40 species) dominated the allogenic component (21 species). The most likely explanation for the large number of fish parasites found at Celestún is the good environmental condition of the lagoon, which allows the completion of parasite life cycles and free circulation of euryhaline fishes from the marine environment bringing marine parasites into the lagoon.

Different expression patterns of renal Na+/K+-ATPase α-isoform-like proteins between tilapia and milkfish following salinity challenges.

PubMed

Yang, Wen-Kai; Chung, Chang-Hung; Cheng, Hui Chen; Tang, Cheng-Hao; Lee, Tsung-Han

2016-12-01

Euryhaline teleosts can survive in a broad range of salinity via alteration of the molecular mechanisms in certain osmoregulatory organs, including in the gill and kidney. Among these mechanisms, Na + /K + -ATPase (NKA) plays a crucial role in triggering ion-transporting systems. The switch of NKA isoforms in euryhaline fish gills substantially contributes to salinity adaptation. However, there is little information about switches in the kidneys of euryhaline teleosts. Therefore, the responses of the renal NKA α-isoform protein switch to salinity challenge in euryhaline tilapia (Oreochromis mossambicus) and milkfish (Chanos chanos) with different salinity preferences were examined and compared in this study. Immunohistochemical staining in tilapia kidneys revealed the localization of NKA in renal tubules rather than in the glomeruli, similar to our previous findings in milkfish kidneys. Protein abundance in the renal NKA pan α-subunit-like, α1-, and α3-isoform-like proteins in seawater-acclimated tilapia was significantly higher than in the freshwater group, whereas the α2-isoform-like protein exhibited the opposite pattern of expression. In the milkfish, higher protein abundance in the renal NKA pan α-subunit-like and α1-isoform-like proteins was found in freshwater-acclimated fish, whereas no difference was found in the protein abundance of α2- and α3-isoform-like proteins between groups. These findings suggested that switches for renal NKA α-isoforms, especially the α1-isoform, were involved in renal osmoregulatory mechanisms of euryhaline teleosts. Moreover, differences in regulatory responses of the renal NKA α-subunit to salinity acclimation between tilapia and milkfish revealed that divergent mechanisms for maintaining osmotic balance might be employed by euryhaline teleosts with different salinity preferences. Copyright © 2016 Elsevier Inc. All rights reserved.

Fish community structure and dynamics in a coastal hypersaline lagoon: Rio Lagartos, Yucatan, Mexico

NASA Astrophysics Data System (ADS)

Vega-Cendejas, Ma. Eugenia; Hernández de Santillana, Mireya

2004-06-01

Rio Lagartos, a tropical coastal lagoon in northern Yucatan Peninsula of Mexico, is characterized by high salinity during most of the year (55 psu annual average). Even though the area has been designated as a wetland of international importance because of its great biodiversity, fish species composition and distribution are unknown. To determine whether the salinity gradient was influencing fish assemblages or not, fish populations were sampled seasonally by seine and trawl from 1992 to 1993 and bimonthly during 1997. We identified 81 fish species, eight of which accounted for 53.1% considering the Importance Value Index ( Floridichthys polyommus, Sphoeroides testudineus, Eucinostomus argenteus, Eucinostomus gula, Fundulus majalis, Strongylura notata, Cyprinodon artifrons and Elops saurus). Species richness and density declined from the mouth to the inner zone where extreme salinity conditions are prominent (>80) and competitive interactions decreased. However, in Coloradas basin (53 average sanity) and in the inlet of the lagoon, the highest fish density and number of species were observed. Greater habitat heterogeneity and fish immigration were considered as the best explanation. Multivariate analysis found three zones distinguished by fish occurrence, abundance and distribution. Ichthyofaunal spatial differences were attributed to selective recruitment from the Gulf of Mexico due to salinity gradient and to changing climatic periods. Estuarine and euryhaline marine species are abundant, with estuarine dependent ones entering the system according to environmental preferences. This knowledge will contribute to the management of the Special Biosphere Reserve through baseline data to evaluate environmental and anthropogenic changes.

Immunolocalization of chloride transporters to gill epithelia of euryhaline teleosts with opposite salinity-induced Na+/K+-ATPase responses.

PubMed

Tang, Cheng-Hao; Hwang, Lie-Yueh; Shen, I-Da; Chiu, Yu-Hui; Lee, Tsung-Han

2011-12-01

Opposite patterns of branchial Na(+)/K(+)-ATPase (NKA) responses were found in euryhaline milkfish (Chanos chanos) and pufferfish (Tetraodon nigroviridis) upon salinity challenge. Because the electrochemical gradient established by NKA is thought to be the driving force for transcellular Cl(-) transport in fish gills, the aim of this study was to explore whether the differential patterns of NKA responses found in milkfish and pufferfish would lead to distinct distribution of Cl(-) transporters in their gill epithelial cells indicating different Cl(-) transport mechanisms. In this study, immunolocalization of various Cl(-) transport proteins, including Na(+)/K(+)/2Cl(-) cotransporter (NKCC), cystic fibrosis transmembrane conductance regulator (CFTR), anion exchanger 1 (AE1), and chloride channel 3 (ClC-3), were double stained with NKA, the basolateral marker of branchial mitochondrion-rich cells (MRCs), to reveal the localization of these transporter proteins in gill MRC of FW- or SW-acclimated milkfish and pufferfish. Confocal microscopic observations showed that the localization of these transport proteins in the gill MRCs of the two studied species were similar. However, the number of gill NKA-immunoreactive (IR) cells in milkfish and pufferfish exhibited to vary with environmental salinities. An increase in the number of NKA-IR cells should lead to the elevation of NKA activity in FW milkfish and SW pufferfish. Taken together, the opposite branchial NKA responses observed in milkfish and pufferfish upon salinity challenge could be attributed to alterations in the number of NKA-IR cells. Furthermore, the localization of these Cl(-) transporters in gill MRCs of the two studied species was identical. It depicted the two studied euryhaline species possess the similar Cl(-) transport mechanisms in gills.

Osmoregulatory actions of the GH/IGF axis in non-salmonid teleosts

USGS Publications Warehouse

Mancera, J.M.; McCormick, S.D.

1998-01-01

Salmonid fishes provided the first findings on the influence of the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis on osmoregulation in teleost fishes. Recent studies on non-salmonid species, however, indicate that this physiological action of the GH/IGF-I axis is not restricted to salmonids or anadromous fishes. GH-producing cells in the pituitary of fish acclimated to different salinities show different degrees of activation depending on the species studied. Plasma GH levels either increase or do not change after transfer of fish from freshwater to seawater. Treatment with GH or IGF-I increases salinity tolerance and/or increases gill Na+,K+-ATPase activity of killifish (Fundulus heteroclitus), tilapia (Oreochromis mossambicus and Oreochromis niloticus) and striped bass (Morone saxatilis). As in salmonids, a positive interaction between GH and cortisol for improving hypoosmoregulatory capacity has been described in tilapia (O. mossambicus). Research on the osmoregulatory role of the GH/IGF-I axis is derived from a small number of teleost species. The study of more species with different osmoregulary patterns will be necessary to fully clarify the osmoregulatory role of GH/IGF-I axis in fish. The available data does suggest, however, that the influence of the GH/IGF-I axis on osmoregulation may be a common feature of euryhalinity in teleosts. Copyright (C) 1998 Elsevier Science Inc.

Differential effects of cortisol and 11-deoxycorticosterone on ion transport protein mRNA levels in gills of two euryhaline teleosts, Mozambique tilapia (Oreochromis mossambicus) and striped bass (Morone saxatilis).

PubMed

Kiilerich, Pia; Tipsmark, Christian K; Borski, Russell J; Madsen, Steffen S

2011-04-01

The role of cortisol as the only corticosteroid in fish osmoregulation has recently been challenged with the discovery of a mineralocorticoid-like hormone, 11-deoxycorticosterone (DOC), and necessitates new studies of the endocrinology of osmoregulation in fish. Using an in vitro gill explant incubation approach, DOC-mediated regulation of selected osmoregulatory target genes in the gill was investigated and compared with that of cortisol in two euryhaline teleosts, Mozambique tilapia (Oreochromis mossambicus) and striped bass (Morone saxatilis). The effects were tested in gills from both fresh water (FW)- and seawater (SW)-acclimated fish. Both cortisol and DOC caused an up-regulation of the Na(+),K(+)-ATPase α1 subunit in SW-acclimated tilapia but had no effect in FW-acclimated fish. Cortisol conferred an increase in Na(+),K(+),2Cl(-) cotransporter (NKCC) isoform 1a transcript levels in FW- and SW-acclimated tilapia, whereas DOC had a stimulatory effect only in SW-acclimated fish. Cortisol had no effect on NKCC isoform 1b mRNA levels at both salinities, while DOC stimulated this isoform in SW-acclimated fish. In striped bass, cortisol conferred an up-regulation of Na(+),K(+)-ATPase α1 and NKCC transcript levels in FW- and SW-acclimated fish, whereas DOC resulted in down-regulation of these transcripts in FW-acclimated fish. It was also found that both corticosteroids may rapidly (30 min) alter the mitogen-activated protein kinase signalling pathway in gill, inducing phosphorylation of extracellular signal-regulated kinase 1 (ERK1) and ERK2 in a salinity-dependent manner. The study shows a disparate organisation of corticosteroid signalling mechanisms involved in ion regulation in the two species and adds new evidence to a role of DOC as a mineralocorticoid hormone in teleosts.

Effects of low environmental salinity on the cellular profiles and expression of Na+, K+-ATPase and Na+, K+, 2Cl- cotransporter 1 of branchial mitochondrion-rich cells in the juvenile marine fish Monodactylus argenteus.

PubMed

Kang, Chao-Kai; Liu, Fu-Chen; Chang, Wen-Been; Lee, Tsung-Han

2012-06-01

The goal of this study was to determine the osmoregulatory ability of a juvenile marine fish, silver moony (Monodactylus argenteus), for the purpose of developing a new experimental species for ecophysiological research. In this study, M. argenteus was acclimated to freshwater (FW), brackish water (BW), or seawater (SW). The salinity tolerance of this euryhaline species was effective, and the fish survived well upon osmotic challenges. The largest apical surface of mitochondrion-rich cells was found in the FW individuals. Immunohistochemical staining revealed that Na(+), K(+)-ATPase immunoreactive (NKA-IR) cells were distributed in the interlamellar region of the gill filaments of the silver moony in all experimental groups. In addition to the filaments, NKA-IR cells were also found in the lamellae of the FW individuals. The number of NKA-IR cells in the gills of the FW individuals exceeded that of the BW and SW individuals. The NKA-IR cells of FW and SW individuals exhibited bigger size than that of BW fish. The NKA activities and protein expression of the NKA α-subunit in the gills of the FW individuals were significantly higher than in the BW and SW groups. Additionally, the relative amounts of Na(+), K(+), 2Cl(-) cotransporter 1 (NKCC1) were salinity-dependent in the gills. Immunofluorescent signals of NKCC1 were localized to the basolateral membrane of NKA-IR cells in all groups. In the gills of the FW individuals, however, some NKA-IR cells did not exhibit a basolateral NKCC1 signal. In conclusion, the present study illustrated the osmoregulatory mechanisms of this easy- and economic-to-rear marine teleost with euryhaline capacity and proved the silver moony to be a good experimental animal.

Cloning of growth hormone, somatolactin, and their receptor mRNAs, their expression in organs, during development, and on salinity stress in the hermaphroditic fish, Kryptolebias marmoratus.

PubMed

Rhee, Jae-Sung; Kim, Bo-Mi; Seo, Jung Soo; Kim, Il-Chan; Lee, Young-Mi; Lee, Jae-Seong

2012-04-01

Salinity is an important parameter that affects survival and metabolism in fish. In fish, pituitary growth hormone (GH) regulates physiological functions including adaptation to different salinity as well as somatic growth. GH is stimulated by growth hormone-releasing hormone (GHRH) and exerts its function via binding to growth hormone receptor (GHR). As Kryptolebias marmoratus is a euryhaline fish, this species would be a useful model species for studying the adaptation to osmotic stress conditions. Here, we cloned GH, -GHR, somatolactin (SL), and somatolactin receptor (SLR) genes, and analyzed their expression patterns in different tissues and during early developmental stages by using real-time RT-PCR. We also further examined expression of them after acclimation to different salinity. Tissue distribution studies revealed that Km-GH and -SL mRNAs were remarkably expressed in brain and pituitary, whereas Km-GHR and -SLR mRNAs were predominantly expressed in liver, followed by gonad, muscle, pituitary, and brain. During embryonic developmental stages, the expression of their mRNA was increased at stage 3 (9 dpf). The Km-GH and -SL mRNA transcripts were constantly elevated until stage 5 (5h post hatch), whereas Km-GHR and -SLR mRNA levels decreased at this stage. After we transferred K. marmoratus from control (12 psu) to hyper-osmotic condition (hyperseawater, HSW; 33 psu), Km-GH, -SL, and GHR mRNA levels were enhanced. In hypo-osmotic conditions like freshwater (FW), Km-GH and -SL expressions were modulated 24 h after exposure, and Km-SLR transcripts were significantly upregulated. This finding suggests that Km-GH and -SL may be involved in the osmoregulatory mechanism under hyper-osmotic as well as hypo-osmotic stress. This is the first report on transcriptional modulation and relationship of GH, GHR, SL, and SLR during early development and after salinity stress. This study will be helpful to a better understanding on molecular mechanisms of adaptation response to salt stress in euryhaline fish. Copyright © 2012 Elsevier Inc. All rights reserved.

Clustering and estimating fish fingerling abundance in a tidal river in close ploximity to a thermal power plant in Southern Thailand

NASA Astrophysics Data System (ADS)

Chesoh, S.; Lim, A.; Luangthuvapranit, C.

2018-04-01

This study aimed to cluster and to quantify the wild-caught fingerlings nearby thermal power plant. Samples were monthly collected by bongo nets from four upstream sites of the Na Thap tidal river in Thailand from 2008 to 2013. Each caught species was identified, counted and calculated density in term of individuals per 1,000 cubic meters. A total of 45 aquatic animal fingerlings was commonly trapped in the average density of 2,652 individuals per 1,000 cubic meters of water volume (1,235–4,570). The results of factor analysis revealed that factor 1 was represented by the largest group of freshwater fish species, factors 2 represented a medium-sized group of mesohaline species, factor 3 represented several brackish species and factor 4 was a few euryhaline species. All four factor reached maximum levels during May to October. Total average numbers of fish fingerling caught at the outflow showed greater than those of other sampling sites. The impact of heated pollution from power plant effluents did not clearly detected. Overall water quality according the Thailand Surface Water Quality Standards Coastal tidal periodic and seasonal runoff phenomena exhibit influentially factors. Continuous ecological monitoring is strongly recommended.

Cell proliferation and apoptosis in the anterior intestine of an amphibious, euryhaline mudskipper (Periophthalmus modestus).

PubMed

Takahashi, H; Sakamoto, T; Narita, K

2006-06-01

In order to replace the diffusive loss of water to the surrounding environment, seawater (SW)-acclimated euryhaline fishes have gastrointestinal tracts with higher ion/water flux in concert with greater permeability, and contrast that to freshwater (FW)-acclimated fish. To understand the cellular basis for these differences, we examined cell proliferation and apoptosis in the anterior intestine of mudskipper transferred from one-third SW to FW or to SW for 1 and 7 days, and those kept out of water for 1 day. The intestinal apoptosis (indicated by DNA laddering) increased during seawater acclimation. TUNEL staining detected numerous apoptotic cells over the epithelium of SW-acclimated fish. Cell proliferation ([3H]thymidine incorporation) in the FW fish was greater than those in SW 7 days after transfer. Labeling with a Proliferating cell nuclear antigen (PCNA) antibody indicated that proliferating cells were greater in number and randomly distributed in the epithelium of FW fish, whereas in SW fish they were almost entirely in the troughs of the intestinal folds. There were no changes in cell turnover in fish kept out of water. During acclimation to different salinities, modification of the cell turnover and abundance may play an important role in regulating the permeability (and transport capacity) of the gastrointestinal tract of fish.

Water transport and functional dynamics of aquaporins in osmoregulatory organs of fishes.

PubMed

Madsen, Steffen S; Engelund, Morten B; Cutler, Christopher P

2015-08-01

Aquaporins play distinct roles for water transport in fishes as they do in mammals-both at the cellular, organ, and organismal levels. However, with over 32,000 known species of fishes inhabiting almost every aquatic environment, from tidal pools, small mountain streams, to the oceans and extreme salty desert lakes, the challenge to obtain consensus as well as specific knowledge about aquaporin physiology in these vertebrate clades is overwhelming. Because the integumental surfaces of these animals are in intimate contact with the surrounding milieu, passive water loss and uptake represent two of the major osmoregulatory challenges that need compensation. However, neither obligatory nor regulatory water transport nor their mechanisms have been elucidated to the same degree as, for example, ion transport in fishes. Currently fewer than 60 papers address fish aquaporins. Most of these papers identify "what is present" and describe tissue expression patterns in various teleosts. The agnathans, chondrichthyans, and functionality of fish aquaporins generally have received little attention. This review emphasizes the functional physiology of aquaporins in fishes, focusing on transepithelial water transport in osmoregulatory organs in euryhaline species - primarily teleosts, but covering other taxonomic groups as well. Most current knowledge comes from teleosts, and there is a strong need for related information on older fish clades. Our survey aims to stimulate new, original research in this area and to bring together new collaborations across disciplines. © 2015 Marine Biological Laboratory.

Increased formation of carcinogenic PAH metabolites in fish promoted by nitrite.

PubMed

Shailaja, M S; Rajamanickam, Rani; Wahidulla, Solimabi

2006-09-01

Nitrite (NO(2)(-)), a highly reactive chemical species, accumulates in coastal waters as a result of pollution with nitrogenous waste and/or an imbalance in the bacterial processes of nitrification and denitrification. The present study probed the impact of nitrite (NO(2)(-)) on the metabolism of polycyclic aromatic hydrocarbons (PAHs) in fish. In a laboratory experiment, exposure of euryhaline fish, Oreochromis mossambicus to industrial effluents containing PAHs in the presence of NO(2)(-) enhanced the cytochrome P450-dependent biotransformation activity determined as 7-ethoxyresorufin-O-deethylase (EROD), by nearly 36% compared to the value observed in the absence of NO(2)(-) (50.2 +/- 6.74 pmol resorufin min(-1) g(-1) liver). Fixed wavelength fluorescence measurements in bile revealed maximum enhancement to have occurred in the metabolites of benzo[a]pyrene, a carcinogenic PAH. Lasting, sublethal physiological deterioration was apparent in fish exposed simultaneously to an oil refinery effluent and NO(2)(-), from the unremittingly decreasing liver somatic index, even after the withdrawal of the contaminants.

Salinity-dependent mechanisms of copper toxicity in the galaxiid fish, Galaxias maculatus.

PubMed

Glover, Chris N; Urbina, Mauricio A; Harley, Rachel A; Lee, Jacqueline A

2016-05-01

The euryhaline galaxiid fish, inanga (Galaxias maculatus) is widely spread throughout the Southern hemisphere occupying near-coastal streams that may be elevated in trace elements such as copper (Cu). Despite this, nothing is known regarding their sensitivity to Cu contamination. The mechanisms of Cu toxicity in inanga, and the ameliorating role of salinity, were investigated by acclimating fish to freshwater (FW), 50% seawater (SW), or 100% SW and exposing them to a graded series of Cu concentrations (0-200μgL(-1)) for 48h. Mortality, whole body Cu accumulation, measures of ionoregulatory disturbance (whole body ions, sodium (Na) influx, sodium/potassium ATPase activity) and ammonia excretion were monitored. Toxicity of Cu was greatest in FW, with mortality likely resulting from impaired Na influx. In both FW and 100% SW, ammonia excretion was significantly elevated, an effect opposite to that observed in previous studies, suggesting fundamental differences in the effect of Cu in this species relative to other studied fish. Salinity was protective against Cu toxicity, and physiology seemed to play a more important role than water chemistry in this protection. Inanga are sensitive to waterborne Cu through a conserved impairment of Na ion homeostasis, but some effects of Cu exposure in this species are distinct. Based on effect concentrations, current regulatory tools and limits are likely protective of this species in New Zealand waters. Copyright © 2016 Elsevier B.V. All rights reserved.

Na+, K+-ATPase β1 subunit associates with α1 subunit modulating a "higher-NKA-in-hyposmotic media" response in gills of euryhaline milkfish, Chanos chanos.

PubMed

Hu, Yau-Chung; Chu, Keng-Fu; Yang, Wen-Kai; Lee, Tsung-Han

2017-10-01

The euryhaline milkfish (Chanos chanos) is a popular aquaculture species that can be cultured in fresh water, brackish water, or seawater in Southeast Asia. In gills of the milkfish, Na + , K + -ATPase (i.e., NKA; sodium pump) responds to salinity challenges including changes in mRNA abundance, protein amount, and activity. The functional pump is composed of a heterodimeric protein complex composed of α- and β-subunits. Among the NKA genes, α1-β1 isozyme comprises the major form of NKA subunits in mammalian osmoregulatory organs; however, most studies on fish gills have focused on the α1 subunit and did not verify the α1-β1 isozyme. Based on the sequenced milkfish transcriptome, an NKA β1 subunit gene was identified that had the highest amino acid homology to β233, a NKA β1 subunit paralog originally identified in the eel. Despite this high level of homology to β233, phylogenetic analysis and the fact that only a single NKA β1 subunit gene exists in the milkfish suggest that the milkfish gene should be referred to as the NKA β1 subunit gene. The results of accurate domain prediction of the β1 subunit, co-localization of α1 and β1 subunits in epithelial ionocytes, and co-immunoprecipitation of α1 and β1 subunits, indicated the formation of a α1-β1 complex in milkfish gills. Moreover, when transferred to hyposmotic media (fresh water) from seawater, parallel increases in branchial mRNA and protein expression of NKA α1 and β1 subunits suggested their roles in hypo-osmoregulation of euryhaline milkfish. This study molecularly characterized the NKA β1 subunit and provided the first evidence for an NKA α1-β1 association in gill ionocytes of euryhaline teleosts.

New insights into gill ionocyte and ion transporter function in euryhaline and diadromous fish

USGS Publications Warehouse

Hiroi, Junya; McCormick, Stephen D.

2012-01-01

Teleost fishes are able to acclimatize to seawater by secreting excess NaCl by means of specialized “ionocytes” in the gill epithelium. Antibodies against Na+/K+-ATPase (NKA) have been used since 1996 as a marker for identifying branchial ionocytes. Immunohistochemistry of NKA by itself and in combination with Na+/K+/2Cl− cotransporter and CFTR Cl− channel provided convincing evidence that ionocytes are functional during seawater acclimation, and also revealed morphological variations in ionocytes among teleost species. Recent development of antibodies to freshwater- and seawater-specific isoforms of the NKA alpha-subunit has allowed functional distinction of ion absorptive and secretory ionocytes in Atlantic salmon. Cutaneous ionocytes of tilapia embryos serve as a model for branchial ionocytes, allowing identification of 4 types: two involved in ion uptake, one responsible for salt secretion and one with unknown function. Combining molecular genetics, advanced imaging techniques and immunohistochemistry will rapidly advance our understanding of both the unity and diversity of ionocyte function and regulation in fish osmoregulation.

Climate extremes drive changes in functional community structure.

PubMed

Boucek, Ross E; Rehage, Jennifer S

2014-06-01

The response of communities to climate extremes can be quite variable. Much of this variation has been attributed to differences in community-specific functional trait diversity, as well as community composition. Yet, few if any studies have explicitly tested the response of the functional trait structure of communities following climate extremes (CEs). Recently in South Florida, two independent, but sequential potential CEs took place, a 2010 cold front, followed by a 2011 drought, both of which had profound impacts on a subtropical estuarine fish community. These CEs provided an opportunity to test whether the structure of South Florida fish communities following each extreme was a result of species-specific differences in functional traits. From historical temperature (1927-2012) and freshwater inflows records into the estuary (1955-2012), we determined that the cold front was a statistically extreme disturbance, while the drought was not, but rather a decadal rare disturbance. The two disturbances predictably affected different parts of functional community structure and thus different component species. The cold front virtually eliminated tropical species, including large-bodied snook, mojarra species, nonnative cichlids, and striped mullet, while having little affect on temperate fishes. Likewise, the drought severely impacted freshwater fishes including Florida gar, bowfin, and two centrarchids, with little effect on euryhaline species. Our findings illustrate the ability of this approach to predict and detect both the filtering effects of different types of disturbances and the implications of the resulting changes in community structure. Further, we highlight the value of this approach to developing predictive frameworks for better understanding community responses to global change. © 2014 John Wiley & Sons Ltd.

A model system using confocal fluorescence microscopy for examining real-time intracellular sodium ion regulation.

PubMed

Lee, Jacqueline A; Collings, David A; Glover, Chris N

2016-08-15

The gills of euryhaline fish are the ultimate ionoregulatory tissue, achieving ion homeostasis despite rapid and significant changes in external salinity. Cellular handling of sodium is not only critical for salt and water balance but is also directly linked to other essential functions such as acid-base homeostasis and nitrogen excretion. However, although measurement of intracellular sodium ([Na(+)]i) is important for an understanding of gill transport function, it is challenging and subject to methodological artifacts. Using gill filaments from a model euryhaline fish, inanga (Galaxias maculatus), the suitability of the fluorescent dye CoroNa Green as a probe for measuring [Na(+)]i in intact ionocytes was confirmed via confocal microscopy. Cell viability was verified, optimal dye loading parameters were determined, and the dye-ion dissociation constant was measured. Application of the technique to freshwater- and 100% seawater-acclimated inanga showed salinity-dependent changes in branchial [Na(+)]i, whereas no significant differences in branchial [Na(+)]i were determined in 50% seawater-acclimated fish. This technique facilitates the examination of real-time changes in gill [Na(+)]i in response to environmental factors and may offer significant insight into key homeostatic functions associated with the fish gill and the principles of sodium ion transport in other tissues and organisms. Copyright © 2016 Elsevier Inc. All rights reserved.

Adaptations of semen characteristics and sperm motility to harsh salinity: Extreme situations encountered by the euryhaline tilapia Sarotherodon melanotheron heudelotii (Dumeril, 1859).

PubMed

Legendre, Marc; Alavi, Sayyed Mohammad Hadi; Dzyuba, Boris; Linhart, Otomar; Prokopchuk, Galina; Cochet, Christophe; Dugué, Rémi; Cosson, Jacky

2016-09-15

In most teleost fishes, sperm cells are quiescent in the seminal plasma and are activated by either a drop (fresh water fish) or an increase in osmolality (marine fish) when released in the water. It is most interesting to examine how the mechanisms of sperm motility activation can adapt to a broad range of salinities, as applies to some euryhaline species, and particularly to the tilapia Sarotherodon melanotheron heudelotii, which can reproduce at salinities from 0 up to 120 in the wild. Here, the gonado-somatic index, semen characteristics, and the osmotic and ionic requirements of sperm motility activation were compared in S. m. heudelotii reared in fresh water (FW), sea water (SW), or hypersaline water (HW; salinities of 0, 35, and 70, respectively). No salinity-dependent differences were found in gonado-somatic index or semen characteristics, except for an increase of seminal plasma osmolality with increasing salinity (from 318 to 349 mOsm kg(-1) in FW and HW fish, respectively). The osmolality range allowing the highest percentages of sperm activation broadened and shifted toward higher values with increasing fish ambient salinity (150-300, 300-800, and 500-1200 mOsm kg(-1), for FW, SW, and HW fish, respectively). Nevertheless, at the three fish rearing salinities, sperm could be activated in media that were hypotonic, isotonic, or hypertonic relative to the seminal plasma, at least when some calcium was present above a threshold concentration. The [Ca(2+)] required for the activation of S. m. heudelotii sperm is (1) higher in fish reared at a higher salinity (2) higher in hypertonic than that in hypotonic activation media, whatever the fish rearing salinity, and (3) higher in the presence of Na(+) or K(+), the negative effects of which increased with an increase in fish rearing salinity. The [Ca(2+)]/[Na(+)] ​ ratios allowing for maximal sperm motility in SW or HW fish are close to those observed in natural environments, either in sea or hypersaline waters. In comparison to most teleosts with external fertilization, the total duration of sperm motility in S. m. heudelotii was exceptionally long (>2 hours regardless the fish rearing salinities). The decrease in sperm activity with increasing time since activation did not result from limiting energy reserves, as the addition of calcium in the activation medium caused most spermatozoa to become motile again. The comparison of sperm characteristics of S. m. heudelotii acclimated from FW to SW or HW with those of fish maintained all lifelong at their native salinity showed that adaptive responses were completed within 2 months or less. Copyright © 2016 Elsevier Inc. All rights reserved.

CORRELATION OF FLAVIN-CONTAINING MONOOXYGENASE ACTIVITY, ALDICARB TOXICITY AND SALINITY IN THE EURYHALINE FISH, JAPANESE MEDAKA (ORYZIAS LATIPES). (R826109)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Effects of salinity on gastric emptying time in hybrid grouper, Epinephelus fuscoguttatus x E. lanceolattus juveniles

NASA Astrophysics Data System (ADS)

Noor, Noorashikin Md.; Das, Simon Kumar; Cob, Zaidi Che; Ghaffar, Mazlan Abd.

2018-04-01

The newly developed hybrid grouper: tiger grouper (Epinephelus fuscoguttatus) × giant grouper (Epinephelus fuscoguttatus) (TG×GG), has a high resistance towards different environmental condition (eg. in euryhaline environment) due to its genetic improvement. This study aims to investigate the effects of different salinities (10, 15, 20, 25 and 30 ppt) on the gastric emptying time (GET) of the TG×GG hybrid grouper juveniles. The fish were fed with commercial pellet over a 30 days experimental period under controlled laboratory conditions. The GET was determined by X-radiographic method, using barium sulfate (BaSO4) as an inert food marker. The X-radiography images showed that the shortest GET (12 h) was observed in the 15 ppt group, whereas the longest GET (18 h) in 30 ppt group. The results suggests to culture TG×GG hybrid grouper juveniles in 15 ppt with commercial pellet diet as this salinity proliferates faster digestion process which may contribute faster growth rate of this important fish species. Overall, these findings would be useful for the betterment of TG×GG hybrid grouper aquaculture which will eventually boost up the production of this newly developed hybrid grouper species.

Effect of outflow on spring and summertime distribution and abundance of larval and juvenile fishes in the upper San Francisco Estuary

USGS Publications Warehouse

Dege, M.; Brown, L.R.

2004-01-01

We analyzed data on spring and summertime larval and juvenile fish distribution and abundance in the upper San Francisco Estuary (SFE), California between 1995 and 2001. The upper SFE includes the tidal freshwater areas of the Sacramento-San Joaquin Delta downstream to the euryhaline environment of San Pablo Bay. The sampling period included years with a variety of outflow conditions. Fifty taxa were collected using a larval tow net. Two common native species, delta smelt Hypomesus transpacifucus and longfin smelt Spirinchus thaleichthys, and four common alien taxa, striped bass Morone saxatilis, threadfin shad Dorosoma petenense, gobies of the genus Tridentiger, and yellowfin goby Acanthogobins flavimanus, were selected for detailed analysis. Outflow conditions had a strong influence on the geographic distribution of most of the species, but distribution with respect to the 2 psu isohaline (X2) was not affected. The distribution patterns of delta smelt, longfin smelt, and striped bass were consistent with larvae moving from upstream freshwater spawning areas to down-stream estuarine rearing areas. There were no obvious relationships of outflow with annual abundance indices. Our results support the idea of using X2 as an organizing principle in understanding the ecology of larval fishes in the upper SFE. Additional years of sampling will likely lead to additional insights into the early life history of upper SFE fishes. ?? Copyright by the American Fisheries Society 2004.

Effects of acclimation salinity on the expression of selenoproteins in the tilapia, Oreochromis mossambicus

PubMed Central

Seale, Lucia A.; Gilman, Christy L.; Moorman, Benjamin P.; Berry, Marla J.; Grau, E. Gordon; Seale, Andre P.

2014-01-01

Selenoproteins are ubiquitously expressed, act on a variety of physiological redox-related processes, and are mostly regulated by selenium levels in animals. To date, the expression of most selenoproteins has not been verified in euryhaline fish models. The Mozambique tilapia, Oreochromis mossambicus, a euryhaline cichlid fish, has a high tolerance for changes in salinity and survives in fresh water (FW) and seawater (SW) environments which differ greatly in selenium availability. In the present study, we searched EST databases for cichlid selenoprotein mRNAs and screened for their differential expression in FW and SW-acclimated tilapia. The expression of mRNAs encoding iodothyronine deiodinases 1, 2 and 3 (Dio1, Dio2, Dio3), Fep15, glutathione peroxidase 2, selenoproteins J, K, L, M, P, S, and W, was measured in the brain, eye, gill, kidney, liver, pituitary, muscle, and intraperitoneal white adipose tissue. Gene expression of selenophosphate synthetase 1, Secp43, and selenocysteine lyase, factors involved in selenoprotein synthesis or in selenium metabolism, were also measured. The highest variation in selenoprotein and synthesis factor mRNA expression between FW- and SW-acclimated fish was found in gill and kidney. While the branchial expression of Dio3 was increased upon transferring tilapia from SW to FW, the inverse effect was observed when fish were transferred from FW to SW. Protein content of Dio3 was higher in fish acclimated to FW than in those acclimated to SW. Together, these results outline tissue distribution of selenoproteins in FW and SW-acclimated tilapia, and indicate that at least Dio3 expression is regulated by environmental salinity. PMID:24854764

Toxicity of analytically cleaned pentabromodiphenylether after prolonged exposure in estuarine European flounder (Platichthys flesus), and partial life-cycle exposure in fresh water zebrafish (Danio rerio).

PubMed

Kuiper, Raoul V; Vethaak, A D; Cantón, Roćio F; Anselmo, Henrique; Dubbeldam, Marco; van den Brandhof, Evert-Jan; Leonards, Pim E G; Wester, Piet W; van den Berg, Martin

2008-09-01

Residues of polybrominated diphenylethers (PBDEs), extensively applied as flame retardants, are widely spread in the aquatic environment and biota. The present study investigates effects of the environmentally relevant lower brominated diphenylethers in two fish species in vivo under controlled laboratory conditions. Euryhaline flounder (Platichthys flesus) and freshwater zebrafish (Danio rerio) were exposed to a range of concentrations of a commercial pentabromodiphenylether mixture, DE-71. Chemical analysis of exposed fish showed a pattern of PBDE congeners that was very similar to that in wild fish. The resulting range included environmentally relevant, as well as higher levels. Animals were investigated histopathologically with emphasis on endocrine and reproductive organs. In zebrafish, hatching of embryos and larval development were assessed. Biochemical parameters were investigated in flounder as markers for suggested dioxin-like activity (ethoxyresorufin-O-deethylase=EROD), and activation of endogenous estrogen synthesis (gonad aromatase activity). Thyroid hormones were analyzed in plasma in both species. Benchmark analysis using internal PBDE concentrations showed a mild dose-dependent decrease of hepatic EROD and ovarian aromatase activities, and plasma thyroxin levels in flounder, and an increase of plasma thyroid hormone levels in zebrafish. These trends did not result in statistically significant differences from control fish, and major histopathological changes were not observed. Reproduction in zebrafish appeared to be the most sensitive parameter with statistically significantly reduced larval survival and non-significant indications for decreased egg production at internal levels that were more than 55 times the highest environmental recordings. The present results indicate limited risk for endocrine or reproductive effects of current environmental PBDE contamination in fish.

Different Modulatory Mechanisms of Renal FXYD12 for Na+-K+-ATPase between Two Closely Related Medakas upon Salinity Challenge

PubMed Central

Yang, Wen-Kai; Kang, Chao-Kai; Hsu, An-Di; Lin, Chia-Hao; Lee, Tsung-Han

2016-01-01

Upon salinity challenge, the Na+-K+-ATPase (NKA) of fish kidney plays a crucial role in maintaining ion and water balance. Moreover, the FXYD protein family was found to be a regulator of NKA. Our preliminary results revealed that fxyd12 was highly expressed in the kidneys of the two closely related euryhaline medaka species (Oryzias dancena and O. latipes) from different natural habitats (brackish water and fresh water). In this study, we investigated the expression and association of renal FXYD12 and NKA α-subunit as well as potential functions of FXYD12 in the two medakas. These findings illustrated and compared the regulatory roles of FXYD12 for NKA in kidneys of the two medakas in response to salinity changes. In this study, at the mRNA and/or protein level, the expression patterns were similar for renal FXYD12 and NKA in the two medakas. However, different patterns of NKA activities and different interaction levels between FXYD12 and NKA were found in the kidneys of these two medakas. The results revealed that different strategies were used in the kidneys of the two medaka species upon salinity challenge. On the other hand, gene knockdown experiments demonstrated that the function of O. dancena FXYD12 allowed maintenance of a high level of NKA activity. The results of the present study indicated that the kidneys of the examined euryhaline medakas originating from brackish water and fresh water exhibited different modulatory mechanisms through which renal FXYD12 enhanced NKA activity to maintain internal homeostasis. Our findings broadened the knowledge of expression and functions of FXYD proteins, the modulators of NKA, in vertebrates. PMID:27194950

Suitability of seagrasses and submerged aquatic vegetation as indicators of eutrophication

EPA Science Inventory

Rooted submerged aquatic vegetation (SAV) encompasses a large diversity of species that range from obligate halophytes such as, seagrasses, to euryhaline species and freshwater obligates. All seagrass and SAV provide key biological functions within the enclosed bays, estuaries, a...

Macrobenthos of Yenisei Bay and the adjacent Kara Sea shelf

NASA Astrophysics Data System (ADS)

Galkin, S. V.; Vedenin, A. A.

2015-07-01

Trawl samples were collected in the northern region of Yenisei Bay and adjacent parts of the Kara Sea shelf. A total of eight stations were taken. We found more than 200 species of benthic organisms. A consecutive replacement of benthic communities is observed when going to the north from the Ob and Yenisei estuaries to the open parts of the sea. We could distinguish four different species complexes in the investigated area: a brackish-water complex where Saduria entomon is dominant; an intermediate complex where S. sibirica, S. sabini and Portlandia aestuariorum are dominant; a transitional complex with P. arctica as a dominant species and with a small amount of Ophiocten sericeum; a marine complex where O. sericeum is dominant. When salinity increased, some brackish-water species were replaced by related euryhaline species. One such example was the replacement of brackish-water Saduria entomon isopods by two euryhaline species: S. sibirica and S. sabini. The consecutive replacement of benthic communities showed a break near Sverdrup Island. In this area the marine complex was replaced by a transitional complex with P. arctica.

The role of salinity in the trophic transfer of 137Cs in euryhaline fish.

PubMed

Pouil, Simon; Oberhänsli, François; Swarzenski, Peter W; Bustamante, Paco; Metian, Marc

2018-09-01

In order to better understand the influence of changing salinity conditions on the trophic transfer of 137 Cs in marine fish that live in dynamic coastal environments, its depuration kinetics was investigated in controlled aquaria. The juvenile turbot Scophthalmus maximus was acclimated to three distinct salinity conditions (10, 25 and 38) and then single-fed with compounded pellets that were radiolabelled with 137 Cs. At the end of a 21-d depuration period, assimilation efficiencies (i.e. AEs = proportion of 137 Cs ingested that is actually assimilated by turbots) were determined from observational data acquired over the three weeks. Our results showed that AEs of 137 Cs in the turbots acclimated to the highest salinity condition were significantly lower than for the other conditions (p < 0.05). Osmoregulation likely explains the decreasing AE observed at the highest salinity condition. Indeed, observations indicate that fish depurate ingested 137 Cs at a higher rate when they increase ion excretion, needed to counterbalance the elevated salinity. Such data confirm that ambient salinity plays an important role in trophic transfer of 137 Cs in some fish species. Implications for such findings extend to seafood safety and climate change impact studies, where the salinity of coastal waters may shift in future years in response to changing weather patterns. Copyright © 2018 Elsevier Ltd. All rights reserved.

Past seawater experience enhances seawater adaptability in medaka, Oryzias latipes.

PubMed

Miyanishi, Hiroshi; Inokuchi, Mayu; Nobata, Shigenori; Kaneko, Toyoji

2016-01-01

During the course of evolution, fishes have acquired adaptability to various salinity environments, and acquirement of seawater (SW) adaptability has played important roles in fish evolution and diversity. However, little is known about how saline environments influence the acquirement of SW adaptability. The Japanese medaka Oryzias latipes is a euryhaline species that usually inhabits freshwater (FW), but is also adaptable to full-strength SW when transferred through diluted SW. In the present study, we examined how past SW experience affects hyposmoregulatory ability in Japanese medaka. For the preparation of SW-experienced fish, FW medaka were acclimated to SW after pre-acclimation to 1/2 SW, and the SW-acclimated fish were transferred back to FW. The SW-experienced fish and control FW fish (SW-inexperienced fish) were transferred directly to SW. Whereas control FW fish did not survive direct transfer to SW, 1/4 of SW-experienced fish adapted successfully to SW. Although there were no significant differences in blood osmolality and plasma Na(+) and Cl(-) concentrations between SW-experienced and control FW medaka in FW, increments in these parameters following SW transfer were lower in SW-experienced fish than in control FW fish. The gene expression of SW-type Na(+), K(+)-ATPase (NKA) in the gills of SW-experienced medaka increased more quickly after direct SW transfer compared with the expression in control FW fish. Prior to SW transfer, the density of NKA-immunoreactive ionocytes in the gills was higher in SW-experienced fish than in control FW fish. Ionocytes expressing CFTR Cl(-) channel at the apical membrane and those forming multicellular complexes, both of which were characteristic of SW-type ionocytes, were also increased in SW-experienced fish. These results indicate that past SW experience enhances the capacity of Na(+) and Cl(-) secretion in ionocytes and thus hypoosmoregulatory ability of Japanese medaka, suggesting the presence of epigenetic mechanisms involved in seawater adaptation.

Relative changes in the abundance of branchial Na(+)/K(+)-ATPase alpha-isoform-like proteins in marine euryhaline milkfish (Chanos chanos) acclimated to environments of different salinities.

PubMed

Tang, Cheng-Hao; Chiu, Yu-Huei; Tsai, Shu-Chuan; Lee, Tsung-Han

2009-08-01

Previous studies revealed that upon salinity challenge, milkfish (Chanos chanos), the euryhaline teleost, exhibited adaptive changes in branchial Na(+)/K(+)-ATPase (NKA) activity with different Na(+) and K(+) affinities. Since alteration of activity and ion-affinity may be influenced by changes in different isoforms of NKA alpha-subunit (i.e., the catalytic subunit), it is, thus, intriguing to compare the patterns of protein abundance of three major NKA alpha-isoform-like proteins (i.e., alpha1, alpha2, and alpha3) in the gills of euryhaline milkfish following salinity challenge. The protein abundance of three NKA alpha-isoform-like proteins in gills of milkfish reared in seawater (SW), fresh water (FW), as well as hypersaline water (HSW, 60 per thousand) were analyzed by immunoblotting. In the acclimation experiments, the SW group revealed significantly higher levels of NKA alpha1- and alpha3-like proteins than the FW or HSW group. Time-course experiments on milkfish that were transferred from SW to HSW revealed the abundance of branchial NKA alpha1-like and alpha3-like proteins decreased significantly after 96 and 12 hr, respectively, and no significant difference was found in NKA alpha2-like protein. Furthermore, when fish were transferred from SW to FW, the amounts of NKA alpha1- and alpha3-like proteins was significantly decreased after 96 hr. Taken together, acute and chronic changes in the abundance of branchial NKA alpha1- and alpha3-like proteins may fulfill the requirements of altering NKA activity with different Na(+) or K(+) affinity for euryhaline milkfish acclimated to environments of various salinities. 2009 Wiley-Liss, Inc.

Population specific sperm production in European flounder Platichthys flesus: adaptation to salinity at spawning.

PubMed

Nissling, A; Larsson, R

2018-06-07

Marine teleosts inhabiting the brackish Baltic Sea have adapted to the less saline water with activation of spermatozoa at low salinity hypo-osmotic conditions but with shorter longevity and lower swimming speed that affect the fertilization capacity. Aiming to elucidate if the fertilization capacity may be maintained by increasing the number of spermatozoa produced, testis size for the euryhaline flounder Platichthys flesus with external fertilization was assessed along a salinity gradient; with spawning at a salinity of c. 7, 10-18 and 30-35. Fulton's condition factor K = 0.881 ± 0.085 (mean ± S.D.), 0.833 ± 0.096 and 0.851 ± 0.086, for fish spawning at salinities of c. 7, 10-18 and 30-35, respectively, with no difference between areas, i.e. analysed fish were in similar nutritional condition. A general linear model, with testes dry mass as the dependent variable and somatic mass as covariate resulted in a significant difference between areas-populations with larger testes for P. flesus spawning at a salinity of c. 7 but no difference between fish spawning at a salinity of 10-18 and 30-35. The result suggests that adaptation by increasing the number of spermatozoa produced may be a key mechanism for marine teleosts spawning in areas with low salinities to sustain the fertilization capacity as shown here for the euryhaline P. flesus. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Effects of salinity on the toxicity and biotransformation of L-selenomethionine in Japanese medaka (Oryzias latipes) embryos: mechanisms of oxidative stress.

PubMed

Lavado, Ramon; Shi, Dalin; Schlenk, Daniel

2012-02-01

Previous studies in mammals have shown that organoselenium depletes the cellular antioxidant, glutathione (GSH) due to activation of organoselenides to organoselenoxides by flavin-containing monooxygenases (FMO). Since FMO tends to be induced in euryhaline fish exposed to hypersaline conditions, the developmental toxicity of salinity and organoselenium was examined in the euryhaline fish Japanese medaka (Oryzias latipes). FMO activity, GSH, and selenium concentrations in Japanese medaka embryos were measured following a 24-h exposure to 0.05 mM L-selenomethionine (SeMet) under different saline conditions: freshwater (<0.5 dS/m), 4.2, 6.7, and 16.8 dS/m. Concentrations of GSH and the hatch-out ratio of the SeMet-treated embryos decreased in a salinity dependent manner. While SeMet treatment led to accumulation within embryos, selenium concentrations were unaltered by salinity treatment. Compared to freshwater-exposed embryos, microsomes from embryos at 6.7 and 16.8 dS/m had enhanced oxidation of SeMet to the selenoxide (10- and 14.3-fold, respectively), which correlated with GSH depletion. The results show that increased SeMet oxidation by hypersaline conditions with subsequent GSH depletion may play an important role in the developmental toxicity of selenomethionine. Copyright © 2011 Elsevier B.V. All rights reserved.

Short-term seaward fish migration in the Messolonghi Etoliko lagoons (Western Greek coast) in relation to climatic variables and the lunar cycle

NASA Astrophysics Data System (ADS)

Katselis, George; Koukou, Katerina; Dimitriou, Evagelos; Koutsikopoulos, Constantin

2007-07-01

In the present study we analysed the daily seaward migratory behaviour of four dominant euryhaline fish species (Mugilidae: Liza saliens, Liza aurata, Mugil cephalus and Sparidae: Sparus aurata) in the Messolonghi Etoliko lagoon system (Western Greek coast) based on the daily landings' time series of barrier traps and assessed the relationship between their migratory behaviour and various climatic variables (air temperature and atmospheric pressure) and the lunar cycle. A 2-year time series of daily fish landings (1993 and 1994), a long time series of daily air temperature and daily temperature range (1991 1998) as well as a 4-year time series of the daily atmospheric pressure (1994 1997) and daily pressure range were used. Harmonic models (HM) consisting of annual and lunar cycle harmonic components explained most (R2 > 0.80) of the mean daily species landings and temperature variations, while a rather low part of the variation (0.18 < R2 < 0.27) was explained for pressure, daily pressure range and daily temperature range. In all the time series sets the amplitude of the annual component was highest. The model values of all species revealed two important migration periods (summer and winter) corresponding to the spawning and refuge migrations. The lunar cycle effect on species' daily migration rates and the short-term fluctuation of daily migration rates were rather low. However, the short-term fluctuation of some species' daily migration rates during winter was greater than during summer. In all species, the main migration was the spawning migration. The model lunar components of the species landings showed a monthly oscillation synchronous to the full moon (S. aurata and M. cephalus) or a semi-monthly oscillation synchronous to the new and full moon (L. aurata and L. saliens). Bispectral analysis of the model values and the model residuals' time series revealed that the species daily migration were correlated (coherencies > 0.6) to the daily fluctuations of the climatic variables at seasonal, mid and short-term scales.

An integrated fish-plankton aquaculture system in brackish water.

PubMed

Gilles, S; Fargier, L; Lazzaro, X; Baras, E; De Wilde, N; Drakidès, C; Amiel, C; Rispal, B; Blancheton, J-P

2013-02-01

Integrated Multi-Trophic Aquaculture takes advantage of the mutualism between some detritivorous fish and phytoplankton. The fish recycle nutrients by consuming live (and dead) algae and provide the inorganic carbon to fuel the growth of live algae. In the meanwhile, algae purify the water and generate the oxygen required by fishes. Such mechanism stabilizes the functioning of an artificially recycling ecosystem, as exemplified by combining the euryhaline tilapia Sarotherodon melanotheron heudelotii and the unicellular alga Chlorella sp. Feed addition in this ecosystem results in faster fish growth but also in an increase in phytoplankton biomass, which must be limited. In the prototype described here, the algal population control is exerted by herbivorous zooplankton growing in a separate pond connected in parallel to the fish-algae ecosystem. The zooplankton production is then consumed by tilapia, particularly by the fry and juveniles, when water is returned to the main circuit. Chlorella sp. and Brachionus plicatilis are two planktonic species that have spontaneously colonized the brackish water of the prototype, which was set-up in Senegal along the Atlantic Ocean shoreline. In our system, water was entirely recycled and only evaporation was compensated (1.5% volume/day). Sediment, which accumulated in the zooplankton pond, was the only trophic cul-de-sac. The system was temporarily destabilized following an accidental rotifer invasion in the main circuit. This caused Chlorella disappearance and replacement by opportunist algae, not consumed by Brachionus. Following the entire consumption of the Brachionus population by tilapias, Chlorella predominated again. Our artificial ecosystem combining S. m. heudelotii, Chlorella and B. plicatilis thus appeared to be resilient. This farming system was operated over one year with a fish productivity of 1.85 kg/m2 per year during the cold season (January to April).

Toxicity and accumulation of mercury in three species of crabs with different osmoregulatory capacities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bianchini, A.; Gilles, R.

1996-07-01

Synergism between mercury and salinity has been shown in invertebrates. Two authors have tied to correlate salinity effects with a higher or lower accumulation of mercury. Zauke, demonstrated lower mercury levels in several benthic invertebrates from limnic regions of the Elbe estuary when compared to those from Marine regions. On the other hand, Kendall did not report any significant difference in mercury concentrations in benthic macroinvertebrates throughout a salinity gradient in two estuaries from Georgia. In species hyperosmoregulating in diluted media, it could, however, be considered that the high water turnover would favor mercury accumulation. In this context, one couldmore » also expect a relationship between environmental salinity and mercury toxicity in different euryhaline species depending on their osmoregulatory capacities. We have tested this hypothesis analyzing the toxic effects and accumulation of mercury in three euryhaline crabs presenting different osmoregulatory capacities: Eriocheir sinensis (strong hyperosmoregulator), Carcinus maenas (weak hyperosmoregulator) and Cancer pagurus (osmoconformer). 16 refs., 4 figs., 1 tab.« less

Evidence for growth hormone/insulin-like growth factor I axis regulation of seawater acclimation in the euryhaline teleost Fundulus heteroclitus

USGS Publications Warehouse

Mancera, J.M.; McCormick, S.D.

1998-01-01

The ability of ovine growth hormone (oGH), recombinant bovine insulin- like growth factor I (rbIGF-I), recombinant human insulin-like growth factor II (rhIGF-II), and bovine insulin to increase hypoosmoregulatory capacity in the euryhaline teleost Fundulus heteroclitus was examined. Fish acclimated to brackish water (BW, 10 ppt salinity, 320 mOsm/kg H2O) were injected with a single dose of hormone and transferred to seawater (SW, 35 ppt salinity, 1120 mOsm/kg H2O) 2 days later. Fish were sampled 24 h after transfer and plasma osmolality, plasma glucose, and gill Na+,K+-ATPase activity were examined. Transfer from BW to SW increased plasma osmolality and gill Na+,K+-ATPase activity. Transfer from BW to BW had no effect on these parameters. rbIGF-I (0.05, 0.1, and 0.2 ??g/g) improved the ability to maintain plasma osmolality and to increase gill Na+, K+-ATPase activity in a dose-dependent manner. oGH (0.5, 1, and 2 ??g/g) also increased hypoosmoregulatory ability but only the higher doses (2 ??g/g) significantly increased gill Na+,K+-ATPase activity. oGH (1 ??g/g) and rbIGF-I (0.1 ??g/g) had a significantly greater effect on plasma osmolality and gill Na+,K+-ATPase activity than either hormone alone. rhIGF-II (0.05, 0.1, and 0.2 ??g/g) and bovine insulin (0.01 and 0.05 ??g/g) were without effect. The results suggest a role of GH and insulin-like growth factor I (IGF-I) in seawater acclimation of E heteroclitus. Based on these findings and previous studies, it is concluded that the capacity of the GH/IGF-I axis to increase hypoosmoregulatory ability may be a common feature of euryhalinity in teleosts.

Salinity-dependent nickel accumulation and oxidative stress responses in the euryhaline killifish (Fundulus heteroclitus).

PubMed

Blewett, Tamzin A; Wood, Chris M

2015-02-01

The mechanisms of nickel (Ni) toxicity in marine fish remain unclear, although evidence from freshwater (FW) fish suggests that Ni can act as a pro-oxidant. This study investigated the oxidative stress effects of Ni on the euryhaline killifish (Fundulus heteroclitus) as a function of salinity. Killifish were exposed to sublethal levels (5, 10, and 20 mg L(-1)) of waterborne Ni for 96 h in FW (0 ppt) and 100 % saltwater (SW) (35 ppt). In general, SW was protective against both Ni accumulation and indicators of oxidative stress [protein carbonyl formation and catalase (CAT) activity]. This effect was most pronounced at the highest Ni exposure level. For example, FW intestine showed increased Ni accumulation relative to SW intestine at 20 mg Ni L(-1), and this was accompanied by significantly greater protein carbonylation and CAT activity in this tissue. There were exceptions, however, in that although liver of FW killifish at the highest exposure concentration showed greater Ni accumulation relative to SW liver, levels of CAT activity were greatly decreased. This may relate to tissue- and salinity-specific differences in oxidative stress responses. The results of the present study suggest (1) that there was Ni-induced oxidative stress in killifish, (2) that the effects of salinity depend on differences in the physiology of the fish in FW versus SW, and (3) that increased levels of cations (sodium, calcium, potassium, and magnesium) and anions (SO4 and Cl) in SW are likely protective against Ni accumulation in tissues exposed to the aquatic environment.

Cardiorespiratory upregulation during seawater acclimation in rainbow trout: effects on gastrointestinal perfusion and postprandial responses.

PubMed

Brijs, Jeroen; Gräns, Albin; Ekström, Andreas; Olsson, Catharina; Axelsson, Michael; Sandblom, Erik

2016-05-01

Increased gastrointestinal blood flow is essential for euryhaline fishes to maintain osmotic homeostasis during the initial phase of a transition from freshwater to seawater. However, the cardiorespiratory responses and hemodynamic changes required for a successful long-term transition to seawater remain largely unknown. In the present study, we simultaneously measured oxygen consumption rate (ṀO2), cardiac output (CO), heart rate (HR), and gastrointestinal blood flow (GBF) in rainbow trout (Oncorhynchus mykiss) acclimated to either freshwater or seawater for at least 6 wk. Seawater-acclimated trout displayed significantly elevated ṀO2 (day: 18%, night: 19%), CO (day: 22%, night: 48%), and GBF (day: 96%, night: 147%), demonstrating that an overall cardiorespiratory upregulation occurs during seawater acclimation. The elevated GBF was achieved via a combination of increased CO, mediated through elevated stroke volume (SV), and a redistribution of blood flow to the gastrointestinal tract. Interestingly, virtually all of the increase in CO of seawater-acclimated trout was directed to the gastrointestinal tract. Although unfed seawater-acclimated trout displayed substantially elevated cardiorespiratory activity, the ingestion of a meal resulted in a similar specific dynamic action (SDA) and postprandial GBF response as in freshwater-acclimated fish. This indicates that the capacity for the transportation of absorbed nutrients, gastrointestinal tissue oxygen delivery, and acid-base regulation is maintained during digestion in seawater. The novel findings presented in this study clearly demonstrate that euryhaline fish upregulate cardiovascular function when in seawater, while retaining sufficient capacity for the metabolic and cardiovascular changes associated with the postprandial response. Copyright © 2016 the American Physiological Society.

Euryhaline pufferfish NBCe1 differs from nonmarine species NBCe1 physiology

PubMed Central

Plata, Consuelo; Kurita, Yukihiro; Kato, Akira; Hirose, Shigehisa; Romero, Michael F.

2012-01-01

Marine fish drink seawater and eliminate excess salt by active salt transport across gill and gut epithelia. Euryhaline pufferfish (Takifugu obscurus, mefugu) forms a CaCO3 precipitate on the luminal gut surface after transitioning to seawater. NBCe1 (Slc4a4) at the basolateral membrane of intestinal epithelial cell plays a major role in transepithelial intestinal HCO3− secretion and is critical for mefugu acclimation to seawater. We assayed fugu-NBCe1 (fNBCe1) activity in the Xenopus oocyte expression system. Similar to NBCe1 found in other species, fNBCe1 is an electrogenic Na+/HCO3− cotransporter and sensitive to the stilbene inhibitor DIDS. However, our experiments revealed several unique and distinguishable fNBCe1 transport characteristics not found in mammalian or other teleost NBCe1-orthologs: electrogenic Li+/nHCO3− cotransport; HCO3− independent, DIDS-insensitive transport; and increased basal intracellular Na+ accumulation. fNBCe1 is a voltage-dependent Na+/nHCO3− cotransporter that rectifies, independently from the extracellular Na+ or HCO3− concentration, around −60 mV. Na+ removal (0Na+ prepulse) is necessary to produce the true HCO3−-elicited current. HCO3− addition results in huge outward currents with quick current decay. Kinetic analysis of HCO3− currents reveals that fNBCe1 has a much higher transport capacity (higher maximum current) and lower affinity (higher Km) than human kidney NBCe1 (hkNBCe1) does in the physiological range (membrane potential = −80 mV; [HCO3−] = 10 mM). In this state, fNBCe1 is in favor of operating as transepithelial HCO3− secretion, opposite of hkNBCe1, from blood to the luminal side. Thus, fugu-NBCe1 represents the first ortholog-based tool to study amino acid substitutions in NBCe1 and how those change ion and voltage dependence. PMID:22159080

Osmoregulation and muscle water control in vitro facing salinity stress of the Amazon fish Oscar Astronotus ocellatus (Cichlidae)

USGS Publications Warehouse

Gutierre, Silvia M. M.; Schulte, Jessica M.; Schofield, Pam; Prodocimo, Viviane

2017-01-01

Specimens of Oscar Astronotus ocellatus from a fish farm were abruptly submitted to salt stress of 14 ppt and 20 ppt, for 3 and 8 h to determine their plasma osmolality. Muscle wet body mass change in vitro was analyzed from control freshwater animals. Fish in 14 ppt presented no osmolality distress even after 8 h. In 20 ppt, a slight increase (10%) in plasma osmolality was observed for both times of exposure when compared to control fish. Muscle slices submitted in vitro to hyper-osmotic saline displayed decreased body mass after 75 min, and slices submitted to hypo-osmotic saline displayed increased body mass after 45 min when compared to control (isosmotic saline). These results reinforce A. ocellatus’s euryhalinity. The fish were able to regulate its internal medium and tolerate 14 ppt, but presented an intense osmotic challenge and low muscle hydration control when facing salinities of 20 ppt.

Bibliography of Venomous and Poisonous Marine Animals and Their Toxins

DTIC Science & Technology

1984-02-01

Miami, Florida, 96p., 1975. 909 MILLS, L.3. and KLEIN-MC PHEE, 901 MC LAUGHLIN, 3.3. Euryhaline G. Toxicity of the New England Chrysomonads: nutrition and...8217leau SOLI, L. Nutritional require- rouge," un pdril pour les hifltres ments and toxicity of two marine perliares. Bl.So.Cent.A ic. A rolijum. 3...Comm. Tech. Pap. (141), Nou- cosas de Yucatan " with notes on mea, New Caledonia, Sept., 1963. the probable identification of fishes. Tex. 3. Sci. 4

RNA-Seq analysis of salinity stress-responsive transcriptome in the liver of spotted sea bass (Lateolabrax maculatus).

PubMed

Zhang, Xiaoyan; Wen, Haishen; Wang, Hailiang; Ren, Yuanyuan; Zhao, Ji; Li, Yun

2017-01-01

Salinity is one of the most prominent abiotic factors, which greatly influence reproduction, development, growth, physiological and metabolic activities of fishes. Spotted sea bass (Lateolabrax maculatus), as a euryhaline marine teleost, has extraordinary ability to deal with a wide range of salinity changes. However, this species is devoid of genomic resources, and no study has been conducted at the transcriptomic level to determine genes responsible for salinity regulation, which impedes the understanding of the fundamental mechanism conferring tolerance to salinity fluctuations. Liver, as the major metabolic organ, is the key source supplying energy for iono- and osmoregulation in fish, however, little attention has been paid to its salinity-related functions but which should not be ignored. In this study, we perform RNA-Seq analysis to identify genes involved in salinity adaptation and osmoregulation in liver of spotted sea bass, generating from the fishes exposed to low and high salinity water (5 vs 30ppt). After de novo assembly, annotation and differential gene expression analysis, a total of 455 genes were differentially expressed, including 184 up-regulated and 271 down-regulated transcripts in low salinity-acclimated fish group compared with that in high salinity-acclimated group. A number of genes with a potential role in salinity adaptation for spotted sea bass were classified into five functional categories based on the gene ontology (GO) and enrichment analysis, which include genes involved in metabolites and ion transporters, energy metabolism, signal transduction, immune response and structure reorganization. The candidate genes identified in L. maculates liver provide valuable information to explore new pathways related to fish salinity and osmotic regulation. Besides, the transcriptomic sequencing data supplies significant resources for identification of novel genes and further studying biological questions in spotted sea bass.

RNA-Seq analysis of salinity stress–responsive transcriptome in the liver of spotted sea bass (Lateolabrax maculatus)

PubMed Central

Zhang, Xiaoyan; Wen, Haishen; Wang, Hailiang; Ren, Yuanyuan; Zhao, Ji; Li, Yun

2017-01-01

Salinity is one of the most prominent abiotic factors, which greatly influence reproduction, development, growth, physiological and metabolic activities of fishes. Spotted sea bass (Lateolabrax maculatus), as a euryhaline marine teleost, has extraordinary ability to deal with a wide range of salinity changes. However, this species is devoid of genomic resources, and no study has been conducted at the transcriptomic level to determine genes responsible for salinity regulation, which impedes the understanding of the fundamental mechanism conferring tolerance to salinity fluctuations. Liver, as the major metabolic organ, is the key source supplying energy for iono- and osmoregulation in fish, however, little attention has been paid to its salinity-related functions but which should not be ignored. In this study, we perform RNA-Seq analysis to identify genes involved in salinity adaptation and osmoregulation in liver of spotted sea bass, generating from the fishes exposed to low and high salinity water (5 vs 30ppt). After de novo assembly, annotation and differential gene expression analysis, a total of 455 genes were differentially expressed, including 184 up-regulated and 271 down-regulated transcripts in low salinity-acclimated fish group compared with that in high salinity-acclimated group. A number of genes with a potential role in salinity adaptation for spotted sea bass were classified into five functional categories based on the gene ontology (GO) and enrichment analysis, which include genes involved in metabolites and ion transporters, energy metabolism, signal transduction, immune response and structure reorganization. The candidate genes identified in L. maculates liver provide valuable information to explore new pathways related to fish salinity and osmotic regulation. Besides, the transcriptomic sequencing data supplies significant resources for identification of novel genes and further studying biological questions in spotted sea bass. PMID:28253338

Ontogenetic development of intestinal length and relationships to diet in an Australasian fish family (Terapontidae)

PubMed Central

2013-01-01

Background One of the most widely accepted ecomorphological relationships in vertebrates is the negative correlation between intestinal length and proportion of animal prey in diet. While many fish groups exhibit this general pattern, other clades demonstrate minimal, and in some cases contrasting, associations between diet and intestinal length. Moreover, this relationship and its evolutionary derivation have received little attention from a phylogenetic perspective. This study documents the phylogenetic development of intestinal length variability, and resultant correlation with dietary habits, within a molecular phylogeny of 28 species of terapontid fishes. The Terapontidae (grunters), an ancestrally euryhaline-marine group, is the most trophically diverse of Australia’s freshwater fish families, with widespread shifts away from animal-prey-dominated diets occurring since their invasion of fresh waters. Results Description of ontogenetic development of intestinal complexity of terapontid fishes, in combination with ancestral character state reconstruction, demonstrated that complex intestinal looping (convolution) has evolved independently on multiple occasions within the family. This modification of ontogenetic development drives much of the associated interspecific variability in intestinal length evident in terapontids. Phylogenetically informed comparative analyses (phylogenetic independent contrasts) showed that the interspecific differences in intestinal length resulting from these ontogenetic developmental mechanisms explained ~65% of the variability in the proportion of animal material in terapontid diets. Conclusions The ontogenetic development of intestinal complexity appears to represent an important functional innovation underlying the extensive trophic differentiation seen in Australia’s freshwater terapontids, specifically facilitating the pronounced shifts away from carnivorous (including invertebrates and vertebrates) diets evident across the family. The capacity to modify intestinal morphology and physiology may also be an important facilitator of trophic diversification during other phyletic radiations. PMID:23441994

Genome and Transcriptome Analyses Provide Insight into the Euryhaline Adaptation Mechanism of Crassostrea gigas

PubMed Central

Zhang, Linlin; Li, Chunyan; Li, Li; She, Zhicai; Huang, Baoyu; Zhang, Guofan

2013-01-01

Background The Pacific oyster, Crassostrea gigas, has developed special mechanisms to regulate its osmotic balance to adapt to fluctuations of salinities in coastal zones. To understand the oyster’s euryhaline adaptation, we analyzed salt stress effectors metabolism pathways under different salinities (salt 5, 10, 15, 20, 25, 30 and 40 for 7 days) using transcriptome data, physiology experiment and quantitative real-time PCR. Results Transcriptome data uncovered 189, 480, 207 and 80 marker genes for monitoring physiology status of oysters and the environment conditions. Three known salt stress effectors (involving ion channels, aquaporins and free amino acids) were examined. The analysis of ion channels and aquaporins indicated that 7 days long-term salt stress inhibited voltage-gated Na+/K+ channel and aquaporin but increased calcium-activated K+ channel and Ca2+ channel. As the most important category of osmotic stress effector, we analyzed the oyster FAAs metabolism pathways (including taurine, glycine, alanine, beta-alanine, proline and arginine) and explained FAAs functional mechanism for oyster low salinity adaptation. FAAs metabolism key enzyme genes displayed expression differentiation in low salinity adapted individuals comparing with control which further indicated that FAAs played important roles for oyster salinity adaptation. A global metabolic pathway analysis (iPath) of oyster expanded genes displayed a co-expansion of FAAs metabolism in C. gigas compared with seven other species, suggesting oyster’s powerful ability regarding FAAs metabolism, allowing it to adapt to fluctuating salinities, which may be one important mechanism underlying euryhaline adaption in oyster. Additionally, using transcriptome data analysis, we uncovered salt stress transduction networks in C. gigas. Conclusions Our results represented oyster salt stress effectors functional mechanisms under salt stress conditions and explained the expansion of FAAs metabolism pathways as the most important effectors for oyster euryhaline adaptation. This study was the first to explain oyster euryhaline adaptation at a genome-wide scale in C. gigas. PMID:23554902

Heterophysiasis, an intestinal fluke infection of man and vertebrates transmitted by euryhaline gastropods and fish

NASA Astrophysics Data System (ADS)

Taraschewski, H.

1984-03-01

Heterophyes heterophyes, agent of human heterophyiasis in the Near East, is transmitted in marine lagoons and saline inland waters, where the euryhaline intermediate hosts are abundant. In Egypt, mullets, the predominant second intermediate hosts, are customarily consumed raw; thus man becomes infected easily. Symptoms of human infections are usually considered mild. Mullets do not seem to be affected by the metacercariae encysted in the muscles, whereas the growth of the snail host Pirenella conica was found to be enhanced due to the infestation by the trematodes. In laboratory experiments, the flukes were found to be well developed in dogs, foxes and cats, but failed to reach sexual maturity in several other potentially piscivorous mammals and birds. In nature, dogs probably serve as the major reservoir hosts. Heterophyiasis is most prevalent in the Nile Delta, a huge brackish water area which is densely populated by humans and, consequently, also by dogs and cats. In the Far East, besides Heterophyes nocens, several other heterophysids with marine or fresh-water life-cycles are known to infect humans.

Salinity-dependent nickel accumulation and effects on respiration, ion regulation and oxidative stress in the galaxiid fish, Galaxias maculatus.

PubMed

Blewett, Tamzin A; Wood, Chris M; Glover, Chris N

2016-07-01

Inanga (Galaxias maculatus) are a euryhaline and amphidromous Southern hemisphere fish species inhabiting waters highly contaminated in trace elements such as nickel (Ni). Ni is known to exert its toxic effects on aquatic biota via three key mechanisms: inhibition of respiration, impaired ion regulation, and stimulation of oxidative stress. Inanga acclimated to freshwater (FW), 50% seawater (SW) or 100% SW were exposed to 0, 150 or 2000 μg Ni L(-1), and tissue Ni accumulation, metabolic rate, ion regulation (tissue ions, calcium (Ca) ion influx), and oxidative stress (catalase activity, protein carbonylation) were measured after 96 h. Ni accumulation increased with Ni exposure concentration in gill, gut and remaining body, but not in liver. Only in the gill was Ni accumulation affected by exposure salinity, with lower branchial Ni burdens in 100% and 50% SW inanga, relative to FW fish. There were no Ni-dependent effects on respiration, or Ca influx, and the only Ni-dependent effect on tissue ion content was on gill potassium. Catalase activity and protein carbonylation were affected by Ni, primarily in FW, but only at 150 μg Ni L(-1). Salinity therefore offsets the effects of Ni, despite minimal changes in Ni bioavailability. These data suggest only minor effects of Ni in inanga, even at highly elevated environmental Ni concentrations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of salinity on flavin-containing monooxygenase expression and activity in rainbow trout (Oncorhynchus mykiss).

PubMed

Larsen, B K; Schlenk, D

2001-06-01

In order to obtain more information about the physiological role(s) of flavin-containing monooxygenases (FMOs) in euryhaline teleost fishes, two experimental series were performed using adult and juvenile rainbow trout (Oncorhynchus mykiss). Cannulated adult trout were exposed to freshwater or 21% seawater for 48 h, whereas juvenile trout were acclimated to one of four different salinities: freshwater, 7%, 14%, or 21% during a 2-week period. FMO expression and activity were determined in red blood cells (RBC), liver, gill, kidney, gut, heart and brain. Furthermore, the content of trimethylamine oxide (TMAO; an FMO metabolite and an osmolyte) as well as urea were determined in various tissues. FMO expression and activity increased significantly and in a salinity dependent manner in osmoregulatory organs (gills, kidney and gut) in both juveniles and adult trout and, furthermore, in RBC in adults. No significant changes were observed in liver or heart. Urea content increased significantly and in a salinity dependent manner in all tissues, whereas TMAO was accumulated primarily in muscle tissue. Salinity dependent adjustment of FMO expression and activity primarily in osmoregulatory organs as well as regulation of TMAO content in muscle is consistent with previous studies showing an association of FMO with osmoregulation in euryhaline teleosts. However, the lack of a parallel increase of TMAO with urea in other tissues of fish at high salinity indicates other mechanisms of protection from intracellular urea may exist in non-muscular tissues.

Hypernatremia in Dice snakes (Natrix tessellata) from a coastal population: implications for osmoregulation in marine snake prototypes.

PubMed

Brischoux, François; Kornilev, Yurii V

2014-01-01

The widespread relationship between salt excreting structures (e.g., salt glands) and marine life strongly suggests that the ability to regulate salt balance has been crucial during the transition to marine life in tetrapods. Elevated natremia (plasma sodium) recorded in several marine snakes species suggests that the development of a tolerance toward hypernatremia, in addition to salt gland development, has been a critical feature in the evolution of marine snakes. However, data from intermediate stage (species lacking salt glands but occasionally using salty environments) are lacking to draw a comprehensive picture of the evolution of an euryhaline physiology in these organisms. In this study, we assessed natremia of free-ranging Dice snakes (Natrix tessellata, a predominantly fresh water natricine lacking salt glands) from a coastal population in Bulgaria. Our results show that coastal N. tessellata can display hypernatremia (up to 195.5 mmol x l(-1)) without any apparent effect on several physiological and behavioural traits (e.g., hematocrit, body condition, foraging). More generally, a review of natremia in species situated along a continuum of habitat use between fresh- and seawater shows that snake species display a concomitant tolerance toward hypernatremia, even in species lacking salt glands. Collectively, these data suggest that a physiological tolerance toward hypernatremia has been critical during the evolution of an euryhaline physiology, and may well have preceded the evolution of salt glands.

Hypernatremia in Dice Snakes (Natrix tessellata) from a Coastal Population: Implications for Osmoregulation in Marine Snake Prototypes

PubMed Central

Brischoux, François; Kornilev, Yurii V.

2014-01-01

The widespread relationship between salt excreting structures (e.g., salt glands) and marine life strongly suggests that the ability to regulate salt balance has been crucial during the transition to marine life in tetrapods. Elevated natremia (plasma sodium) recorded in several marine snakes species suggests that the development of a tolerance toward hypernatremia, in addition to salt gland development, has been a critical feature in the evolution of marine snakes. However, data from intermediate stage (species lacking salt glands but occasionally using salty environments) are lacking to draw a comprehensive picture of the evolution of an euryhaline physiology in these organisms. In this study, we assessed natremia of free-ranging Dice snakes (Natrix tessellata, a predominantly fresh water natricine lacking salt glands) from a coastal population in Bulgaria. Our results show that coastal N. tessellata can display hypernatremia (up to 195.5 mmol.l−1) without any apparent effect on several physiological and behavioural traits (e.g., hematocrit, body condition, foraging). More generally, a review of natremia in species situated along a continuum of habitat use between fresh- and seawater shows that snake species display a concomitant tolerance toward hypernatremia, even in species lacking salt glands. Collectively, these data suggest that a physiological tolerance toward hypernatremia has been critical during the evolution of an euryhaline physiology, and may well have preceded the evolution of salt glands. PMID:24658047

Habitat Use and Trophic Structure in a Highly Migratory Predatory Fish Identified with Geochemical Proxies in Scales

NASA Astrophysics Data System (ADS)

Seeley, M.; Walther, B. D.

2016-02-01

Atlantic tarpon, Megalops atlanticus, are highly migratory euryhaline predators that occupy different habitats throughout ontogeny. Specifically, Atlantic tarpon are known to inhabit oligohaline waters, although the frequency and duration of movements across estuarine gradients into these waters are relatively unknown. This species supports over a two billion dollar industry within the Gulf of Mexico and is currently listed as vulnerable under the International Union for the Conservation of Nature (IUCN). A new non-lethal method for reconstructing migrations across estuaries relies on trace element and stable isotope compositions of growth increments in scales. We analyzed Atlantic tarpon scales from the Texas coast to validate this method using inductively coupled plasma mass spectrometry (ICP-MS) for trace elements and isotope ratio mass spectrometry (IR-MS) for stable isotope ratios. Multiple scales were also taken from the same individual to confirm the consistency of elemental uptake within the same individual. Results show that scale Ba:Ca, Sr:Ca and δ13C are effective proxies for salinity, while enrichments in δ15N are consistent with known ontogenetic trophic shifts. In addition, chemical transects across multiple scales from the same individual were highly consistent, suggesting that any non-regenerated scale removed from a fish can provide equivalent time series. Continuous life history profiles of scales were obtained via laser ablation transects of scale cross-sections to quantify trace element concentrations from the core (youngest increments) to the edge (oldest increments). Stable isotope and trace element results together indicate that behavior is highly variable between individuals, with some but not all fish transiting estuarine gradients into oligohaline waters. Our findings will provide novel opportunities to investigate alternative non-lethal methods to monitor fish migrations across chemical gradients.

INFLUENCE OF LOWERED SALINITY AND ELEVATED CADMIUM ON THE SURVIVAL AND METAMORPHOSIS OF TROCHOPHORES IN CAPITELLA SP. I

EPA Science Inventory

It is well known that the competent larvae of many marine invertebrate species can be stimulated to metamorphose by exposing them to elevated concentrations of certain ions, neuroactive substances, and pharmacological agents. In this study we report that larvae of the euryhaline ...

Some euryhalinity may be more common than expected in marine elasmobranchs: the example of the South American skate Zapteryx brevirostris (Elasmobranchii, Rajiformes, Rhinobatidae).

PubMed

Wosnick, Natascha; Freire, Carolina A

2013-09-01

Elasmobranchs are essentially marine, but ~15% of the species occur in brackish or freshwater. The Brazilian marine coastal skate Zapteryx brevirostris, non-reported in nearby estuaries, was submitted to 35, 25, 15, and 5 psu, for 6 or 12h (n=6). Plasma was assayed for osmolality, urea, and ions (Na(+), Cl(-), K(+), Mg(2+)). Muscle water content was determined, and the rectal gland, kidney and gills were removed for carbonic anhydrase (CA) and Na(+),K(+)-ATPase (NKA) activities. The skate survived to all treatments. Plasma osmolality and urea levels decreased respectively by 27% and 38% after 12h in 5 psu (with respect to levels when in seawater), but plasma Na(+), Cl(-), and Mg(2+) were well regulated. Plasma K(+) showed some conformation after 12h. Muscle hydration was maintained. Branchial CA and NKA did not respond to salinity. Rectal gland NKA decreased upon seawater dilution, while renal NKA increased. This skate was shown to be partially euryhaline. The analysis of plasma urea of elasmobranchs in brackish and freshwater versus salinity and time-allied to the widespread occurrence of some euryhalinity in the group-led us to revisit the hypothesis of a brackish water habitat for elasmobranch ancestors. Copyright © 2013 Elsevier Inc. All rights reserved.

Salinity tolerance and osmotic response of the estuarine hermit crab Pagurus maclaughlinae in the Indian River Lagoon, Florida

NASA Astrophysics Data System (ADS)

Rhodes-Ondi, Sarah E.; Turner, Richard L.

2010-01-01

Pagurus maclaughlinae is the most common hermit in the Indian River Lagoon System. Wide variations in lagoonal salinity make it likely that P. maclaughlinae is euryhaline and that other hermit species in the area are more stenohaline, at least in some stages of their life histories. In a study of salinity tolerance, crabs were held unfed at salinities of 5-50 (25 control) for up to 30 days. Based on survivorship curves, P. maclaughlinae tolerated acute exposure to salinities of 10-45 for up to 18 days, and survivorship up to 30 days at 20-45 equaled or exceeded survivorship of the control. In a study of acclimation, the osmotic pressure of hemolymph was measured after crabs were held in the laboratory for 12, 48, and 96 h acutely exposed to salinities of 10-45. Paired t-tests revealed that the crabs weakly hyperregulated their hemolymph at 45-154 mOsmol above the external medium at all salinities and sampling times, and the osmotic differential of their hemolymph was fully acclimated by 96 h. In a third study, acclimatization of hemolymph was studied on crabs at four field sites that differed in their recent salinity histories. Field-collected crabs weakly regulated their hemolymph 72-84 mOsmol above the external medium at all sites sampled. Performance did not differ by site. The range of salinity tolerance and acclimation of hemolymph of P. maclaughlinae partly explain their wide distribution, and the consistent osmotic differential of its hemolymph indicates that the osmoregulatory ability of this small-bodied species is conserved in populations throughout the lagoon. Although some other larger-bodied hermit species in the region are euryhaline as adults, their tendency to hyperregulate strongly at low salinities possibly adds an energetic burden that, along with their less euryhaline long-lived larvae, might exclude them from the lagoon. Salinity tolerance of larval P. maclaughlinae has yet to be studied.

Mechanism of osmoregulatory adaptation in tilapia.

PubMed

Yan, Biao; Wang, Zhen-Hua; Zhao, Jin-Liang

2013-02-01

The shortage of freshwater resource in many countries leads to a shift to develop aquaculture in brackish water and sea water. Tilapias are euryhaline that can thrive from freshwater to full sea water. They and their hybrids are the best candidate species for cultivation in brackish habitats. Thus, understanding their osmoregulatory mechanisms will help to breed or genetically engineer salt tolerant species. In this paper, we review recent progress in understanding the mechanisms of osmoregulatory adaptations in tilapia.

Responses of free radical metabolism to air exposure or salinity stress, in crabs (Callinectes danae and C. ornatus) with different estuarine distributions.

PubMed

Freire, Carolina A; Togni, Valéria G; Hermes-Lima, Marcelo

2011-10-01

The swimming crabs Callinectes danae and C. ornatus are found in bays and estuaries, but C. danae is more abundant in lower salinities, while C. ornatus remains restricted to areas of higher salinity. Experimental crabs of both species were submitted to: air exposure (Ae, 3h), reimmersion in 33‰ (control) sea water (SW) (Ri, 1h) following air exposure; hyposaline (Ho, 10‰ for 2h) or hypersaline (He, 40‰ for 2h) SW, then return to control 33‰ SW (RHo and RHe, for 1h). Hemolymph was sampled for osmolality and chloride determinations. Activity of antioxidant enzymes [glutathione peroxidase (GPX), catalase, glutathione-S-transferase] and levels of carbonyl proteins and lipid peroxidation (TBARS) were evaluated in hepatopancreas, muscle, anterior and posterior gills. In Ho groups, hemolymph concentrations were lower in both species, compared to He groups. C. danae displayed higher control activities of GPX (hepatopancreas and muscle) and catalase (all four tissues) than C. ornatus. C. ornatus presented increased activities of catalase and GPX in Ae, Ri, and He groups. Increased TBARS was seen in C. ornatus tissues (He group). The more euryhaline species displayed higher constitutive activities of antioxidant enzymes, and the less euryhaline species exhibited activation of these enzymes when exposed to air or hyper-salinity. Copyright © 2011 Elsevier Inc. All rights reserved.

FXYD8, a Novel Regulator of Renal Na+/K+-ATPase in the Euryhaline Teleost, Tetraodon nigroviridis

PubMed Central

Wang, Pei-Jen; Yang, Wen-Kai; Lin, Chia-Hao; Hwang, Hau-Hsuan; Lee, Tsung-Han

2017-01-01

FXYD proteins are important regulators of Na+/K+-ATPase (NKA) activity in mammals. As an inhabitant of estuaries, the pufferfish (Tetraodon nigroviridis) responds to ambient salinity changes with efficient osmoregulation, including alterations in branchial, and renal NKA activities. Previous studies on teleostean FXYDs have mainly focused on the expression and potential functions of FXYD proteins in gills. The goal of the present study was to elucidate the potential role of FXYD8, a member of the fish FXYD protein family, in the modulation of NKA activity in the kidneys of this euryhaline pufferfish by using molecular, biochemical, and physiological approaches. The results demonstrate that T. nigroviridis FXYD8 (TnFXYD8) interacts with NKA in renal tubules. Meanwhile, the protein expression of renal TnFXYD8 was found to be significantly upregulated in hyperosmotic seawater-acclimated pufferfish. Moreover, overexpression of TnFXYD8 in Xenopus oocytes decreased NKA activity. Our results suggest the FXYD8 is able to modulate NKA activity through inhibitory effects upon salinity challenge. The present study further extends our understanding of the functions of FXYD proteins, the regulators of NKA, in vertebrates. PMID:28848450

Aggressive desert goby males also court more, independent of the physiological demands of salinity.

PubMed

Lehtonen, Topi K; Svensson, P Andreas; Wong, Bob B M

2018-06-19

Both between- and within-individual variation in behaviour can be important in determining mating opportunities and reproductive outcomes. Such behavioural variability can be induced by environmental conditions, especially if individuals vary in their tolerance levels or resource allocation patterns. We tested the effects of exposure to different salinity levels on male investment into two important components of mating success-intrasexual aggression and intersexual courtship-in a fish with a resource defence mating system, the desert goby, Chlamydogobius eremius. We found that males that were more aggressive to rivals also exhibited higher rates of courtship displays towards females. Contrary to predictions, this positive relationship, and the consistency of the two behaviours, were not affected by the salinity treatment, despite the physiological costs that high salinity imposes on the species. Moreover, over the entire data-set, there was only a marginally non-significant tendency for males to show higher levels of aggression and courtship in low, than high, salinity. The positive correlation between male aggression and courtship, independent of the physiological demands of the environment, suggests that males are not inclined to make contrasting resource investments into these two key reproductive behaviours. Instead, in this relatively euryhaline freshwater species, typical investment into current reproductive behaviours can occur under a range of different salinity conditions.

Quantitative Molecular Phenotyping of Gill Remodeling in a Cichlid Fish Responding to Salinity Stress*

PubMed Central

Kültz, Dietmar; Li, Johnathon; Gardell, Alison; Sacchi, Romina

2013-01-01

A two-tiered label-free quantitative (LFQ) proteomics workflow was used to elucidate how salinity affects the molecular phenotype, i.e. proteome, of gills from a cichlid fish, the euryhaline tilapia (Oreochromis mossambicus). The workflow consists of initial global profiling of relative tryptic peptide abundances in treated versus control samples followed by targeted identification (by MS/MS) and quantitation (by chromatographic peak area integration) of validated peptides for each protein of interest. Fresh water acclimated tilapia were independently exposed in separate experiments to acute short-term (34 ppt) and gradual long-term (70 ppt, 90 ppt) salinity stress followed by molecular phenotyping of the gill proteome. The severity of salinity stress can be deduced with high technical reproducibility from the initial global label-free quantitative profiling step alone at both peptide and protein levels. However, an accurate regulation ratio can only be determined by targeted label-free quantitative profiling because not all peptides used for protein identification are also valid for quantitation. Of the three salinity challenges, gradual acclimation to 90 ppt has the most pronounced effect on gill molecular phenotype. Known salinity effects on tilapia gills, including an increase in the size and number of mitochondria-rich ionocytes, activities of specific ion transporters, and induction of specific molecular chaperones are reflected in the regulation of abundances of the corresponding proteins. Moreover, specific protein isoforms that are responsive to environmental salinity change are resolved and it is revealed that salinity effects on the mitochondrial proteome are nonuniform. Furthermore, protein NDRG1 has been identified as a novel key component of molecular phenotype restructuring during salinity-induced gill remodeling. In conclusion, besides confirming known effects of salinity on gills of euryhaline fish, molecular phenotyping reveals novel insight into proteome changes that underlie the remodeling of tilapia gill epithelium in response to environmental salinity change. PMID:24065692

Discovery of the invasive Mayan Cichlid fish "Cichlasoma" urophthalmus (Günther 1862) in Thailand, with comments on other introductions and potential impacts

USGS Publications Warehouse

Nico, Leo G.; Beamish, William H.; Musikasinthorn, Prachya

2007-01-01

We report on the occurrence and possible establishment of a non-native cichlid fish in a brackish-water system in the lower Chao Phraya River delta region, Thailand. Although, the possibility of some degree of introgressive hybridization can not be ruled out, Thailand specimens agree best with Mayan Cichlid “Cichlasoma” urophthalmus (Günther 1862). Our collections represent the first records of this New World, highly-invasive, euryhaline fish from Thailand and coincides with recent collections from Singapore. Positive identification of specimens as “C.” urophthalmus requires caution due to the diversity of the Cichlidae (>1,300 species), widespread introduction of many family members, variation within species, extensive interspecific overlap in characters, and proliferation of artificial cichlid hybrids (e.g., Flowerhorns). We first became aware of the Thailand population in 2005 when “C.” urophthalmus began appearing in the catches of local fishermen. We visited the site in November 2006 and obtained and examined voucher specimens. The abundance and wide size range of juveniles and adults in local ponds and an adjacent canal is evidence of natural reproduction. Because water bodies throughout the Chao Phraya delta are interconnected and subject to flooding, it is likely that “C.” urophthalmus is already established and is dispersing, but surveys and monitoring are needed to determine their exact geographic range. The Thailand population is compared to “C.” urophthalmus introduced into Florida (USA). Based on what is known about Florida “C.” urophthalmus, it is predicted that this cichlid will further invade coastal and inland waters in Thailand and elsewhere in Southeast Asia. This cichlid has a long history in the aquarium trade in Europe. However, there are no records from the wild in European waters and, because of the colder climate, the possibility of establishment in that region is relatively low.

Salinity-induced regulation of the myo-inositol biosynthesis pathway in tilapia gill epithelium

PubMed Central

Sacchi, Romina; Li, Johnathon; Villarreal, Fernando; Gardell, Alison M.; Kültz, Dietmar

2013-01-01

SUMMARY The myo-inositol biosynthesis (MIB) pathway converts glucose-6-phosphate to the compatible osmolyte myo-inositol that protects cells from osmotic stress. Using proteomics, the enzymes that constitute the MIB pathway, myo-inositol phosphate synthase (MIPS) and inositol monophosphatase 1 (IMPA1), are identified in tilapia (Oreochromis mossambicus) gill epithelium. Targeted, quantitative, label-free proteomics reveals that they are both upregulated during salinity stress. Upregulation is stronger when fish are exposed to severe (34 ppt acute and 90 ppt gradual) relative to moderate (70 ppt gradual) salinity stress. IMPA1 always responds more strongly than MIPS, suggesting that MIPS is more stable during salinity stress. MIPS is N-terminally acetylated and the corresponding peptide increases proportionally to MIPS protein, while non-acetylated N-terminal peptide is not detectable, indicating that MIPS acetylation is constitutive and may serve to stabilize the protein. Hyperosmotic induction of MIPS and IMPA1 is confirmed using western blot and real-time qPCR and is much higher at the mRNA than at the protein level. Two distinct MIPS mRNA variants are expressed in the gill, but one is more strongly regulated by salinity than the other. A single MIPS gene is encoded in the tilapia genome whereas the zebrafish genome lacks MIPS entirely. The genome of euryhaline tilapia contains four IMPA genes, two of which are expressed, but only one is salinity regulated in gill epithelium. The genome of stenohaline zebrafish contains a single IMPA gene. We conclude that the MIB pathway represents a major salinity stress coping mechanism that is regulated at multiple levels in euryhaline fish but absent in stenohaline zebrafish. PMID:24072791

Measuring titratable alkalinity by single versus double endpoint titration: An evaluation in two cyprinodont species and implications for characterizing net H+ flux in aquatic organisms.

PubMed

Brix, Kevin V; Wood, Chris M; Grosell, Martin

2013-01-01

In this study, Na(+) uptake and acid-base balance in the euryhaline pupfish Cyprinodon variegatus variegatus were characterized when fish were exposed to pH 4.5 freshwater (7mM Na(+)). Similar to the related cyprinodont, Fundulus heteroclitus, Na(+) uptake was significantly inhibited when exposed to low pH water. However, it initially appeared that C. v. variegatus increased apparent net acid excretion at low pH relative to circumneutral pH. This result is opposite to previous observations for F. heteroclitus under similar conditions where fish were observed to switch from apparent net H(+) excretion at circumneutral pH to apparent net H(+) uptake at low pH. Further investigation revealed disparate observations between these studies were the result of using double endpoint titrations to measure titratable alkalinity fluxes in the current study, while the earlier study utilized single endpoint titrations to measure these fluxes (i.e.,. Cyprinodon acid-base transport is qualitatively similar to Fundulus when characterized using single endpoint titrations). This led to a comparative investigation of these two methods. We hypothesized that either the single endpoint methodology was being influenced by a change in the buffer capacity of the water (e.g., mucus being released by the fish) at low pH, or the double endpoint methodology was not properly accounting for ammonia flux by the fish. A series of follow-up experiments indicated that buffer capacity of the water did not change significantly, that excretion of protein (a surrogate for mucus) was actually reduced at low pH, and that the double endpoint methodology does not properly account for NH(3) excretion by fish under low pH conditions. As a result, it overestimates net H(+) excretion during low pH exposure. After applying the maximum possible correction for this error (i.e., assuming that all ammonia is excreted as NH(3)), the double endpoint methodology indicates that net H(+) transport was reduced to effectively zero in both species at pH 4.5. However, significant differences between the double endpoint (no net H(+) transport at low pH) and single endpoint titrations (net H(+) uptake at low pH) remain to be explained. Copyright © 2012 Elsevier Inc. All rights reserved.

Liver transcriptome analysis reveals extensive transcriptional plasticity during acclimation to low salinity in Cynoglossus semilaevis.

PubMed

Si, Yufeng; Wen, Haishen; Li, Yun; He, Feng; Li, Jifang; Li, Siping; He, Huiwen

2018-06-18

Salinity is an important abiotic stress that influences the physiological and metabolic activity, reproduction, growth and development of marine fish. It has been suggested that half-smooth tongue sole (Cynoglossus semilaevis), a euryhaline fish species, uses a large amount of energy to maintain osmotic pressure balance when exposed to fluctuations in salinity. To delineate the molecular response of C. semilaevis to different levels of salinity, we performed RNA-seq analysis of the liver to identify the genes and molecular and biological processes involved in responding to salinity changes. The present study yielded 330.4 million clean reads, of which 83.9% were successfully mapped to the reference genome of C. semilaevis. One hundred twenty-eight differentially expressed genes (DEGs), including 43 up-regulated genes and 85 down-regulated genes, were identified. These DEGs were highly represented in metabolic pathways, steroid biosynthesis, terpenoid backbone biosynthesis, butanoate metabolism, glycerolipid metabolism and the 2-oxocarboxylic acid metabolism pathway. In addition, genes involved in metabolism, osmoregulation and ion transport, signal transduction, immune response and stress response, and cytoskeleton remodeling were affected during acclimation to low salinity. Genes acat2, fdps, hmgcr, hmgcs1, mvk, pmvk, ebp, lss, dhcr7, and dhcr24 were up-regulated and abat, ddc, acy1 were down-regulated in metabolic pathways. Genes aqp10 and slc6a6 were down-regulated in osmoregulation and ion transport. Genes abat, fdps, hmgcs1, mvk, pmvk and dhcr7 were first reported to be associated with salinity adaptation in teleosts. Our results revealed that metabolic pathways, especially lipid metabolism were important for salinity adaptation. The candidate genes identified from this study provide a basis for further studies to investigate the molecular mechanism of salinity adaptation and transcriptional plasticity in marine fish.

Osmotic/ionic status of body fluids in the euryhaline cephalopod suggest possible parallel evolution of osmoregulation

PubMed Central

Sakamoto, Tatsuya; Ogawa, Satoshi; Nishiyama, Yudai; Akada, Chiaki; Takahashi, Hideya; Watanabe, Taro; Minakata, Hiroyuki; Sakamoto, Hirotaka

2015-01-01

Acclimation from marine to dilute environments constitutes among the dramatic evolutionary transitions in the history of life. Such adaptations have evolved in multiple lineages, but studies of the blood/hemolymph homeostasis mechanisms are limited to those using evolutionarily advanced Deuterostome (chordates) and Ecdysozoa (crustaceans). Here, we examined hemolymph homeostasis in the advanced Lophotrochozoa/mollusc, the other unexplored taxa, and its possible regulation by the vasopressin/oxytocin superfamily peptides known to be implicated in fluid homeostasis in Chordata and Arthropoda. The hemolymph osmotic and ionic status in the euryhaline cephalopod (Octopus ocellatus) following transfer from 30-ppt normal seawater to 20 ppt salinity indicate hyperosmo- and hyperionoregulatory abilities for more than 1 week, as in crustaceans and teleost fish. While ventilation frequency decreased by 1 day, Na+/K+-ATPase activity, which has been generally implicated in ion transport, was induced in two of the eight posterior gills after 1 week. In addition, the octopuses were intravenously injected with 1 or 100 ng/g octopressin or cephalotocin, which are Octopus vasopressin/oxytocin orthologs. After 1 day, octopressin, but not cephalotocin, decreased the hemolymph osmolality and Ca concentrations, as well as urinary Na concentrations. These data provide evidence for possible parallel evolution in hyperionoregulatory mechanisms and coordination by conserved peptides. PMID:26403952

Tilapia and human CLIC2 structures are highly conserved.

PubMed

Zeng, Jiao; Li, Zhengjun; Lui, Eei Yin; Lam, Siew Hong; Swaminathan, Kunchithapadam

2018-01-08

Chloride intracellular channels (CLICs) exist in soluble and membrane bound forms. We have determined the crystal structure of soluble Clic2 from the euryhaline teleost fish Oreochromis mossambicus. Structural comparison of tilapia and human CLIC2 with other CLICs shows that these proteins are highly conserved. We have also compared the expression levels of clic2 in selected osmoregulatory organs of tilapia, acclimated to freshwater, seawater and hypersaline water. Structural conservation of vertebrate CLICs implies that they might play conserved roles. Also, tissue-specific responsiveness of clic2 suggests that it might be involved in iono-osmoregulation under extreme conditions in tilapia. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of somatostatin on the growth hormone-insulin-like growth factor axis and seawater adaptation of rainbow trout (Oncorhynchus mykiss)

USGS Publications Warehouse

Poppinga, J.; Kittilson, J.; McCormick, S.D.; Sheridan, M.A.

2007-01-01

Growth hormone (GH) has been shown to contribute to the seawater (SW) adaptability of euryhaline fish both directly and indirectly through insulin-like growth factor-1 (IGF-1). This study examined the role of somatostatin-14 (SS-14), a potent inhibitor of GH, on the GH-IGF-1 axis and seawater adaptation. Juvenile rainbow trout (Oncorhynchus mykiss) were injected intraperitoneally with SS-14 or saline and transferred to 20??ppt seawater. A slight elevation in plasma chloride levels was accompanied by significantly reduced gill Na+, K+-ATPase activity in SS-14-treated fish compared to control fish 12??h after SW transfer. Seawater increased hepatic mRNA levels of GH receptor 1 (GHR 1; 239%), GHR 2 (48%), and IGF-1 (103%) in control fish 12??h after transfer. Levels of GHR 1 (155%), GHR 2 (121%), IGF-1 (200%), IGF-1 receptor A (IGFR1A; 62%), and IGFR1B (157%) increased in the gills of control fish 12??h after transfer. SS-14 abolished or attenuated SW-induced changes in the expression of GHR, IGF-1, and IGFR mRNAs in liver and gill. These results indicate that SS-14 reduces seawater adaptability by inhibiting the GH-IGF-1 axis. ?? 2007 Elsevier B.V. All rights reserved.

Dietary electrolyte balance affects growth performance, amylase activity and metabolic response in the meagre (Argyrosomus regius).

PubMed

Magnoni, Leonardo J; Salas-Leiton, Emilio; Peixoto, Maria-João; Pereira, Luis; Silva-Brito, Francisca; Fontinha, Filipa; Gonçalves, José F M; Wilson, Jonathan M; Schrama, Johan W; Ozório, Rodrigo O A

2017-09-01

Dietary ion content is known to alter the acid-base balance in freshwater fish. The current study investigated the metabolic impact of acid-base disturbances produced by differences in dietary electrolyte balance (DEB) in the meagre (Argyrosomus regius), an euryhaline species. Changes in fish performance, gastric chyme characteristics, pH and ion concentrations in the bloodstream, digestive enzyme activities and metabolic rates were analyzed in meagre fed ad libitum two experimental diets (DEB 200 or DEB 700mEq/kg) differing in the Na 2 CO 3 content for 69days. Fish fed the DEB 200 diet had 60-66% better growth performance than the DEB 700 group. Meagre consuming the DEB 200 diet were 90-96% more efficient than fish fed the DEB 700 diet at allocating energy from feed into somatic growth. The pH values in blood were significantly lower in the DEB 700 group 2h after feeding when compared to DEB 200, indicating that acid-base balance in meagre was affected by electrolyte balance in diet. Osmolality, and Na + and K + concentrations in plasma did not vary with the dietary treatment. Gastric chyme in the DEB 700 group had higher pH values, dry matter, protein and energy contents, but lower lipid content than in the DEB 200 group. Twenty-four hours after feeding, amylase activity was higher in the gastrointestinal tract of DEB 700 group when compared to the DEB 200 group. DEB 700 group had lower routine metabolic (RMR) and standard metabolic (SMR) rates, indicating a decrease in maintenance energy expenditure 48h after feeding the alkaline diet. The current study demonstrates that feeding meagre with an alkaline diet not only causes acid-base imbalance, but also negatively affects digestion and possibly nutrient assimilation, resulting in decreased growth performance. Copyright © 2017 Elsevier Inc. All rights reserved.

Otolith shape analysis and mitochondrial DNA markers distinguish three sand smelt species in the Atherina boyeri species complex in western Mediterranean

NASA Astrophysics Data System (ADS)

Boudinar, A. S.; Chaoui, L.; Quignard, J. P.; Aurelle, D.; Kara, M. H.

2016-12-01

Atherina boyeri is a common euryhaline teleost fish in the Mediterranean and adjacent areas, which inhabits coastal and estuarine waters, including coastal lagoons and more rarely inland waters. Several recent studies have pointed the possible existence of three distinct groups or species, one lagoon/freshwater group and two 'punctuated and unpunctuated on the flanks' marine groups, within an A. boyeri species complex. This study is a combined approach using otolith shape and molecular markers to better define the structure of the species in the western Mediterranean. Genetic differentiation and species delimitation among nine Atherina boyeri populations from several marine and lagoon/brakish habitat sites in Algeria, Tunisia and France were investigated using three mitochondrial (control region, Cyt b and 16S) and one nuclear markers (2nd intron of S7). For further phylogenetic and phylogeographic study, we added sequences from Genbank covering more areas (Ionian Sea, Adriatic Sea, Tyrrhenian Sea, Black Sea, Atlantic). Five groups were found. Two of them perfectly corresponded to two species already recognized Atherina presbyter and Atherina hepsetus, both living in marine waters; and three additional, including Atherina boyeri (brackish and freshwater environments) and two independent groups of marine punctated and unpunctated individuals. Those findings are corroborated by the study of the otolith contour shape of 362 individuals of seven populations from different habitats using Fourier analysis. Individuals could be discriminated into five groups based on the first two functions (Wilk's lambda = 0.07, p < 0.001). Samples from Ziama inlet, marine punctuated individuals and unpunctuated marine specimens from Annaba's Gulf formed three well separated groups. Specimens from Mellah and Mauguio lagoons formed another group. The last one includes individuals from Bizerte and Thau lagoons. The divergences between them strongly support the potential species within the A. boyeri species complex.

Plasticity of skin water permeability and skin thickness in the amphibious mangrove rivulus Kryptolebias marmoratus.

PubMed

Heffell, Quentin; Turko, Andy J; Wright, Patricia A

2018-03-01

The skin of amphibious fishes is a multipurpose organ, important for gas and ion exchange and nitrogen excretion when fish are out of water (emersed). We tested the hypothesis that skin permeability is altered to maintain water balance through changes in water permeability and skin thickness during salinity acclimation and/or when fish emerse, using the euryhaline, amphibious fish Kryptolebias marmoratus as a model. We first recorded the behaviour of fish out of water to determine which part of the cutaneous surface was in contact with the substrate. Fish spent about 70% of their time on their ventral surface when out of water. Osmotic permeability of the skin was assessed in fish acclimated to 0.3 or 45‰ using 3 H 2 O fluxes in an in vitro micro-Ussing chamber setup. In freshwater-acclimated fish, 3 H 2 O influx across the skin was significantly higher compared to hypersaline-acclimated fish, with no significant changes in efflux. Prolonged emersion (7 days) resulted in an increase in skin 3 H 2 O influx, but not efflux in fish acclimated to a moist 45‰ substrate. In a separate experiment, dorsal epidermal skin thickness increased while the ventral dermis thickness decreased in fish emersed for over a week. However, there was no link between regional skin thickness and water flux in our experiments. Taken together, these findings suggest that K. marmoratus alter skin permeability to maximize water uptake while emersed in hypersaline conditions, adjustments that probably help them survive months of emersion during the dry season when drinking to replace water loss is not possible.

Pathogenic ability and saline stress tolerance of two Fusarium isolates from Odontesthes bonariensis eggs.

PubMed

Pacheco Marino, Suani G; Cabello, Marta N; Dinolfo, María I; Stenglein, Sebastián A; Saparrat, Mario C N; Salibián, Alfredo

2016-01-01

Several fungal species represent a potential risk to embryos of Odontesthes bonariensis (Cuvier and Valenciennes, 1835), a euryhaline freshwater fish that lives in the Pampean inland waters and has potential economic relevance. To identify two fungi isolated from O. bonariensis eggs exposed to saline conditions and to characterize their pathogenicity and tolerance to sodium chloride solutions. The isolates were identified by morphological features, and a preliminar phylogenetic analysis using sequences of translation elongation factor 1-alpha (EF-1α) and calmodulin (CAM) was performed. Koch's postulates were tested to identify the causative agent of fungal infection. The influence of NaCl on the fungal growth was evaluated in in vitro assays. The isolates LPSC 1001 and 1002 were identified as representatives of the genus Fusarium, and belonging to the Fusarium incarnatum-Fusarium equiseti species complex (FIESC) and the Fusarium solani species complex (FSSC), respectively. Histological observations on eggs exposed in vitro to both isolates in infectivity assays confirmed the ability of the fungal isolates to penetrate to egg's chorionic membrane, leading to the death of embryos. Increasing NaCl concentration in the culture medium reduced the growth of the isolates LPSC 1001 and 1002, being completely inhibited at 160 and 120g/l NaCl respectively. The isolates LPSC 1001 (FIESC) and 1002 (FSSC) were identified as fungal pathogens to O. bonariensis eggs. The use of NaCl solutions as antifungal treatment was not effective to control the infection with these strains. Copyright © 2014 Asociación Española de Micología. Published by Elsevier Espana. All rights reserved.

Polyvalent cation receptor proteins (CaRs) are salinity sensors in fish.

PubMed

Nearing, J; Betka, M; Quinn, S; Hentschel, H; Elger, M; Baum, M; Bai, M; Chattopadyhay, N; Brown, E M; Hebert, S C; Harris, H W

2002-07-09

To determine whether calcium polyvalent cation-sensing receptors (CaRs) are salinity sensors in fish, we used a homology-based cloning strategy to isolate a 4.1-kb cDNA encoding a 1,027-aa dogfish shark (Squalus acanthias) kidney CaR. Expression studies in human embryonic kidney cells reveal that shark kidney senses combinations of Ca(2+), Mg(2+), and Na(+) ions at concentrations present in seawater and kidney tubules. Shark kidney is expressed in multiple shark osmoregulatory organs, including specific tubules of the kidney, rectal gland, stomach, intestine, olfactory lamellae, gill, and brain. Reverse transcriptase-PCR amplification using specific primers in two teleost fish, winter flounder (Pleuronectes americanus) and Atlantic salmon (Salmo salar), reveals a similar pattern of CaR tissue expression. Exposure of the lumen of winter flounder urinary bladder to the CaR agonists, Gd(3+) and neomycin, reversibly inhibit volume transport, which is important for euryhaline teleost survival in seawater. Within 24-72 hr after transfer of freshwater-adapted Atlantic salmon to seawater, there are increases in their plasma Ca(2+), Mg(2+), and Na(+) that likely serve as a signal for internal CaRs, i.e., brain, to sense alterations in salinity in the surrounding water. We conclude that CaRs act as salinity sensors in both teleost and elasmobranch fish. Their tissue expression patterns in fish provide insights into CaR functions in terrestrial animals including humans.

Small-sized euryhaline fish as intermediate hosts of the digenetic trematode Cryptocotyle concavum

NASA Astrophysics Data System (ADS)

Zander, C. D.; Kollra, H.-G.; Antholz, B.; Meyer, W.; Westphal, D.

1984-03-01

Cercariae of the trematode Cryptocotyle concavum, which encyst in skin and/or kidney of sticklebacks and gobies, were studied in the Schlei Fjord (western Baltic Sea). Mean incidence of dermal cysts was 48 % in Gasterosteus aculeatus and 37 % in Pungitius pungitius. No cysts were found in the kidneys of sticklebacks. While 97 % of Pomatoschistus microps had encysted metacercariae in the kidneys, only 2 % had cysts in the skin. Pomatoschistus minutus, however, showed hardly any cyst infestation of either skin or kidney. In P. microps the intensity of infestation by metacercariae was frequently more than 50 cysts; in contrast, sticklebacks rarely exhibited more than 5 dermal cysts. Infested fish were larger than 10 mm in total length, the incidence rate increasing with growth. Parasitic infestation depends on ambient salinity: C. concavum was not found at salinities below 4 ‰. In contrast to the high incidence in fish, the first hosts — the snails Hydrobia stagnalis and H. neglecta — showed remarkably low infection rates (3 to 5 %). The findings reported are related to the distribution of C. concavum, the mode of life of infested fish, the feeding habits of the final hosts and the infestation of P. microps by other parasites. Evidently, P. microps represents an optimal second host for C. concavum.

Expression and Localization of Aquaporin 1a in the Sea-Bass (Dicentrarchus labrax) during Ontogeny

PubMed Central

Giffard-Mena, Ivone; Boulo, Viviane; Abed, Charline; Cramb, Gordon; Charmantier, Guy

2011-01-01

The successful establishment of a species in a given habitat depends on the ability of each of its developing stages to adapt to the environment. In order to understand this process we have studied the adaptation of a euryhaline fish, the sea-bass Dicentrarchus labrax, to various salinities during its ontogeny. The expression and localization of Aquaporin 1a (AQP1a) mRNA and protein were determined in different osmoregulatory tissues. In larvae, the sites of AQP1a expression are variable and they shift according to age, implying functional changes. In juveniles after metamorphosis (D32–D48 post-hatch, 15–25 mm) and in pre-adults, an increase in AQP1a transcript abundance was noted in the digestive tract, and the AQP1a location was observed in the intestine. In juveniles (D87–D100 post-hatch, 38–48 mm), the transcript levels of AQP1a in the digestive tract and in the kidney were higher in sea water (SW) than at lower salinity. These observations, in agreement with existing models, suggest that in SW-acclimated fish, the imbibed water is absorbed via AQP1a through the digestive tract, particularly the intestine and the rectum. In addition, AQP1a may play a role in water reabsorption in the kidney. These mechanisms compensate dehydration in SW, and they contribute to the adaptation of juveniles to salinity changes during sea-lagoon migrations. These results contribute to the interpretation of the adaptation of populations to habitats where salinity varies. PMID:21808622

Prolactin and growth hormone in fish osmoregulation

USGS Publications Warehouse

Sakamoto, T.; McCormick, S.D.

2006-01-01

Prolactin is an important regulator of multiple biological functions in vertebrates, and has been viewed as essential to ion uptake as well as reduction in ion and water permeability of osmoregulatory surfaces in freshwater and euryhaline fish. Prolactin-releasing peptide seems to stimulate prolactin expression in the pituitary and peripheral organs during freshwater adaptation. Growth hormone, a member of the same family of hormones as prolactin, promotes acclimation to seawater in several teleost fish, at least in part through the action of insulin-like growth factor I. In branchial epithelia, development and differentiation of the seawater-type chloride cell (and their underlying biochemistry) is regulated by GH, IGF-I, and cortisol, whereas the freshwater-type chloride cell is regulated by prolactin and cortisol. In the epithelia of gastrointestinal tract, prolactin induces cell proliferation during freshwater adaptation, whereas cortisol stimulates both cell proliferation and apoptosis. We propose that control of salinity acclimation in teleosts by prolactin and growth hormone primarily involves regulation of cell proliferation, apoptosis, and differentiation (the latter including upregulation of specific ion transporters), and that there is an important interaction of these hormones with corticosteroids. ?? 2005 Elsevier Inc. All rights reserved.

Molecular Characterization and Expression of α-Globin and β-Globin Genes in the Euryhaline Flounder (Platichthys flesus)

PubMed Central

Lu, Weiqun; Mayolle, Aurelie; Cui, Guoqiang; Luo, Lei; Balment, Richard J.

2011-01-01

In order to understand the possible role of globin genes in fish salinity adaptation, we report the molecular characterization and expression of all four subunits of haemoglobin, and their response to salinity challenge in flounder. The entire open reading frames of α1-globin and α2-globin genes were 432 and 435 bp long, respectively, whereas the β1-globin and β2-globin genes were both 447 bp. Although the head kidney (pronephros) is the predicted major site of haematopoiesis, real-time PCR revealed that expression of α-globin and β-globin in kidney (mesonephros) was 1.5 times higher than in head kidney. Notably, the α1-globin and β1-globin mRNA expression was higher than α2-globin and β2-globin in kidney. Expression levels of all four globin subunits were higher in freshwater- (FW-) than in seawater- (SW-)adapted fish kidney. If globins do play a role in salinity adaptation, this is likely to be more important in combating the hemodilution faced by fish in FW than the dehydration and salt loading which occur in SW. PMID:21969841

Branchial osmoregulation in the euryhaline bull shark, Carcharhinus leucas: a molecular analysis of ion transporters.

PubMed

Reilly, Beau D; Cramp, Rebecca L; Wilson, Jonathan M; Campbell, Hamish A; Franklin, Craig E

2011-09-01

Bull sharks, Carcharhinus leucas, are one of only a few species of elasmobranchs that live in both marine and freshwater environments. Osmoregulation in euryhaline elasmobranchs is achieved through the control and integration of various organs (kidney, rectal gland and liver) in response to changes in environmental salinity. However, little is known regarding the mechanisms of ion transport in the gills of euryhaline elasmobranchs and how they are affected by osmoregulatory challenges. This study was conducted to gain insight into the branchial ion and acid-base regulatory mechanisms of C. leucas by identifying putative ion transporters and determining whether their expression is influenced by environmental salinity. We hypothesised that expression levels of the Na(+)/K(+)-ATPase (NKA) pump, Na(+)/H(+) exchanger 3 (NHE3), vacuolar-type H(+)-ATPase (VHA) and anion exchanger pendrin (PDN) would be upregulated in freshwater (FW) C. leucas. Immunohistochemistry was used to localise all four ion transporters in gills of bull sharks captured in both FW and estuarine/seawater (EST/SW) environments. NHE3 immunoreactivity occurred in the apical region of cells with basolateral NKA expression whereas PDN was apically expressed in cells that also exhibited basolateral VHA immunoreactivity. In accordance with our hypotheses, quantitative real-time PCR showed that the mRNA expression of NHE3 and NKA was significantly upregulated in gills of FW-captured C. leucas relative to EST/SW-captured animals. These data suggest that NHE3 and NKA together may be important in mediating branchial Na(+) uptake in freshwater environments, whereas PDN and VHA might contribute to Cl(-)/HCO(3)(-) transport in marine and freshwater bull shark gills.

Interactive effects of salinity on metabolic rate, activity, growth and osmoregulation in the euryhaline milkfish (Chanos chanos)

PubMed

Swanson

1998-12-01

The euryhaline milkfish (Chanos chanos) is an excellent subject for studies of the physiological and behavioral processes involved in salinity adaptation. In this study, energy partitioning for metabolism, activity and growth, maximal activity performance and blood osmotic concentrations were assessed at two activity levels in juvenile milkfish fed equal rations and maintained at a relatively constant temperature (262 C) and at salinities (15, 35 and 55 ?) that represented a wide range of osmoregulatory challenges. Changes in the measured parameters were not consistently related to the magnitude of the trans-integumentary osmotic gradients. Routine oxygen consumption rates were high in 35 ? salinity (mean 1 s.e.m. 1678 mg O2 kg-1 h-1) and comparably low in 15 and 55 ? salinity (1336 and 1273 mg O2 kg-1 h-1, respectively). Routine activity levels (relative swimming velocity) were highest in 35 ? salinity (0. 960.04 L s-1), where L is standard length, intermediate in 15 ? salinity (0.770.03 L s-1) and lowest in 55 ? salinity (0.670.03 L s-1). Growth was significantly higher in 55 ? salinity (3.40.2 % increase in wet body mass per day) than in 35 ? salinity (2.40.2 % increase per day) and intermediate in 15 ? salinity (2.90.5 % increase per day). Maximum swimming velocities decreased with increases in salinity, from 9.90.7 L s-1 in 15 ? salinity to 6.60. 5 L s-1 in 55 ? salinity. Sustained swimming activity above routine levels for 2 h resulted in an increase in blood osmotic concentrations in milkfish in 55 ? salinity, but osmoregulation was re-established during the second 2 h of activity. Thus, patterns of variation in metabolic rate and growth were largely parallel to variations in routine activity although, comparing 15 and 55 ? salinity, elevated maintenance costs for osmoregulation at the high salinity were detectable. Reduced osmoregulatory abilities and reductions in maximal swimming performance suggest that high salinity may constrain activity. The results demonstrate that investigations of salinity adaptation in euryhaline fishes should take into account the interactive effects of salinity on physiology and behavior.

A New Role for Carbonic Anhydrase 2 in the Response of Fish to Copper and Osmotic Stress: Implications for Multi-Stressor Studies

PubMed Central

de Polo, Anna; Margiotta-Casaluci, Luigi; Lockyer, Anne E.; Scrimshaw, Mark D.

2014-01-01

The majority of ecotoxicological studies are performed under stable and optimal conditions, whereas in reality the complexity of the natural environment faces organisms with multiple stressors of different type and origin, which can activate pathways of response often difficult to interpret. In particular, aquatic organisms living in estuarine zones already impacted by metal contamination can be exposed to more severe salinity variations under a forecasted scenario of global change. In this context, the present study aimed to investigate the effect of copper exposure on the response of fish to osmotic stress by mimicking in laboratory conditions the salinity changes occurring in natural estuaries. We hypothesized that copper-exposed individuals are more sensitive to osmotic stresses, as copper affects their osmoregulatory system by acting on a number of osmotic effector proteins, among which the isoform two of the enzyme carbonic anhydrase (CA2) was identified as a novel factor linking the physiological responses to both copper and osmotic stress. To test this hypothesis, two in vivo studies were performed using the euryhaline fish sheepshead minnow (Cyprinodon variegatus) as test species and applying different rates of salinity transition as a controlled way of dosing osmotic stress. Measured endpoints included plasma ions concentrations and gene expression of CA2 and the α1a-subunit of the enzyme Na+/K+ ATPase. Results showed that plasma ions concentrations changed after the salinity transition, but notably the magnitude of change was greater in the copper-exposed groups, suggesting a sensitizing effect of copper on the responses to osmotic stress. Gene expression results demonstrated that CA2 is affected by copper at the transcriptional level and that this enzyme might play a role in the observed combined effects of copper and osmotic stress on ion homeostasis. PMID:25272015

Natural or Artificial? Habitat-Use by the Bull Shark, Carcharhinus leucas

PubMed Central

Werry, Jonathan M.; Lee, Shing Y.; Lemckert, Charles J.; Otway, Nicholas M.

2012-01-01

Background Despite accelerated global population declines due to targeted and illegal fishing pressure for many top-level shark species, the impacts of coastal habitat modification have been largely overlooked. We present the first direct comparison of the use of natural versus artificial habitats for the bull shark, Carcharhinus leucas, an IUCN ‘Near-threatened’ species - one of the few truly euryhaline sharks that utilises natural rivers and estuaries as nursery grounds before migrating offshore as adults. Understanding the value of alternate artificial coastal habitats to the lifecycle of the bull shark is crucial for determining the impact of coastal development on this threatened but potentially dangerous species. Methodology/Findings We used longline surveys and long-term passive acoustic tracking of neonate and juvenile bull sharks to determine the ontogenetic value of natural and artificial habitats to bull sharks associated with the Nerang River and adjoining canals on the Gold Coast, Australia. Long-term movements of tagged sharks suggested a preference for the natural river over artificial habitat (canals). Neonates and juveniles spent the majority of their time in the upper tidal reaches of the Nerang River and undertook excursions into adjoining canals. Larger bull sharks ranged further and frequented the canals closer to the river mouth. Conclusions/Significance Our work suggests with increased destruction of natural habitats, artificial coastal habitat may become increasingly important to large juvenile bull sharks with associated risk of attack on humans. In this system, neonate and juvenile bull sharks utilised the natural and artificial habitats, but the latter was not the preferred habitat of neonates. The upper reaches of tidal rivers, often under significant modification pressure, serve as nursery sites for neonates. Analogous studies are needed in similar systems elsewhere to assess the spatial and temporal generality of this research. PMID:23166772

Natural or artificial? Habitat-use by the bull shark, Carcharhinus leucas.

PubMed

Werry, Jonathan M; Lee, Shing Y; Lemckert, Charles J; Otway, Nicholas M

2012-01-01

Despite accelerated global population declines due to targeted and illegal fishing pressure for many top-level shark species, the impacts of coastal habitat modification have been largely overlooked. We present the first direct comparison of the use of natural versus artificial habitats for the bull shark, Carcharhinus leucas, an IUCN 'Near-threatened' species--one of the few truly euryhaline sharks that utilises natural rivers and estuaries as nursery grounds before migrating offshore as adults. Understanding the value of alternate artificial coastal habitats to the lifecycle of the bull shark is crucial for determining the impact of coastal development on this threatened but potentially dangerous species. We used longline surveys and long-term passive acoustic tracking of neonate and juvenile bull sharks to determine the ontogenetic value of natural and artificial habitats to bull sharks associated with the Nerang River and adjoining canals on the Gold Coast, Australia. Long-term movements of tagged sharks suggested a preference for the natural river over artificial habitat (canals). Neonates and juveniles spent the majority of their time in the upper tidal reaches of the Nerang River and undertook excursions into adjoining canals. Larger bull sharks ranged further and frequented the canals closer to the river mouth. Our work suggests with increased destruction of natural habitats, artificial coastal habitat may become increasingly important to large juvenile bull sharks with associated risk of attack on humans. In this system, neonate and juvenile bull sharks utilised the natural and artificial habitats, but the latter was not the preferred habitat of neonates. The upper reaches of tidal rivers, often under significant modification pressure, serve as nursery sites for neonates. Analogous studies are needed in similar systems elsewhere to assess the spatial and temporal generality of this research.

Expression of arginine kinase enzymatic activity and mRNA in gills of the euryhaline crabs Carcinus maenas and Callinectes sapidus.

PubMed

Kotlyar, S; Weihrauch, D; Paulsen, R S; Towle, D W

2000-08-01

Phosphagen kinases catalyze the reversible dephosphorylation of guanidino phosphagens such as phosphocreatine and phosphoarginine, contributing to the restoration of adenosine triphosphate concentrations in cells experiencing high and variable demands on their reserves of high-energy phosphates. The major invertebrate phosphagen kinase, arginine kinase, is expressed in the gills of two species of euryhaline crabs, the blue crab Callinectes sapidus and the shore crab Carcinus maenas, in which energy-requiring functions include monovalent ion transport, acid-base balance, nitrogen excretion and gas exchange. The enzymatic activity of arginine kinase approximately doubles in the ion-transporting gills of C. sapidus, a strong osmoregulator, when the crabs are transferred from high to low salinity, but does not change in C. maenas, a more modest osmoregulator. Amplification and sequencing of arginine kinase cDNA from both species, accomplished by reverse transcription of gill mRNA and the polymerase chain reaction, revealed an open reading frame coding for a 357-amino-acid protein. The predicted amino acid sequences showed a minimum of 75 % identity with arginine kinase sequences of other arthropods. Ten of the 11 amino acid residues believed to participate in arginine binding are completely conserved among the arthropod sequences analyzed. An estimation of arginine kinase mRNA abundance indicated that acclimation salinity has no effect on arginine kinase gene transcription. Thus, the observed enhancement of enzyme activity in C. sapidus probably results from altered translation rates or direct activation of pre-existing enzyme protein.

Poecilia vivipara Bloch & Schneider, 1801 (Cyprinodontiformes, Poeciliidae), a guppy in an oceanic archipelago: from where did it come?

PubMed

Berbel-Filho, Waldir Miron; Barros-Neto, Luciano Freitas; Dias, Ricardo Marques; Mendes, Liana Figueiredo; Figueiredo, Carlos Augusto Assumpção; Torres, Rodrigo Augusto; Lima, Sergio Maia Queiroz

2018-01-01

Poecilia vivipara , a small euryhaline guppy is reported at the Maceió River micro-basin in the Fernando de Noronha oceanic archipelago, northeast Brazil. However, the origin (human-mediated or natural dispersal) of this insular population is still controversial. The present study investigates how this population is phylogenetically related to the surrounding continental populations using the cytochrome oxidase I mitochondrial gene from eleven river basins in South America. Our phylogenetic reconstruction showed a clear geographical distribution arrangement of P. vivipara lineages. The Fernando de Noronha haplotype fell within the 'north' clade, closely related to a shared haplotype between the Paraíba do Norte and Potengi basins; the geographically closest continental drainages. Our phylogenetic reconstruction also showed highly divergent lineages, suggesting that P. vivipara may represent a species complex along its wide distribution. Regarding to the insular population, P. vivipara may have been intentionally introduced to the archipelago for the purpose of mosquito larvae control during the occupation of a U.S. military base following World War II. However, given the euryhaline capacity of P. vivipara , a potential scenario of natural (passive or active) dispersal cannot be ruled out.

Poecilia vivipara Bloch & Schneider, 1801 (Cyprinodontiformes, Poeciliidae), a guppy in an oceanic archipelago: from where did it come?

PubMed Central

Berbel-Filho, Waldir Miron; Barros-Neto, Luciano Freitas; Dias, Ricardo Marques; Mendes, Liana Figueiredo; Figueiredo, Carlos Augusto Assumpção; Torres, Rodrigo Augusto; Lima, Sergio Maia Queiroz

2018-01-01

Abstract Poecilia vivipara, a small euryhaline guppy is reported at the Maceió River micro-basin in the Fernando de Noronha oceanic archipelago, northeast Brazil. However, the origin (human-mediated or natural dispersal) of this insular population is still controversial. The present study investigates how this population is phylogenetically related to the surrounding continental populations using the cytochrome oxidase I mitochondrial gene from eleven river basins in South America. Our phylogenetic reconstruction showed a clear geographical distribution arrangement of P. vivipara lineages. The Fernando de Noronha haplotype fell within the 'north' clade, closely related to a shared haplotype between the Paraíba do Norte and Potengi basins; the geographically closest continental drainages. Our phylogenetic reconstruction also showed highly divergent lineages, suggesting that P. vivipara may represent a species complex along its wide distribution. Regarding to the insular population, P. vivipara may have been intentionally introduced to the archipelago for the purpose of mosquito larvae control during the occupation of a U.S. military base following World War II. However, given the euryhaline capacity of P. vivipara, a potential scenario of natural (passive or active) dispersal cannot be ruled out. PMID:29674897

A new species of the ghost shrimp genus Lepidophthalmus (Crustacea: Decapoda: Axiidea) from the southwestern Gulf of Mexico.

PubMed

Felder, Darryl L

2015-07-13

A new species of Lepidophthalmus lacking a ventral median sclerite on the second abdominal somite is described from coastal waters of the southwestern Gulf of Mexico. Lepidophthalmus statoni sp. nov., originally recognized only as a unique population in allozyme studies, is sympatric with the ventrally plated species Lepidophthalmus manningi Felder & Staton, 2000, but more closely resembles Lepidophthalmus louisianensis (Schmitt, 1935) from the northern and northwestern Gulf of Mexico. Apparently restricted to intertidal and shallow subtidal tropical waters, the new species is known to range from western Campeche to middle-upper reaches of Veracruz, Mexico. As many members of the genus, it commonly inhabits euryhaline inlets, estuaries, and protected shorelines, including richly organic muddy to clayey sands and sandy muds adjacent to shoreline vegetation. Coloration is documented and discussed as a tool to facilitate field identifications, as are morphological characters.

Hypersalinity Acclimation Increases the Toxicity of the Insecticide Phorate in Coho Salmon (Oncorhynchus kisutch)

PubMed Central

Lavado, Ramon; Maryoung, Lindley A.; Schlenk, Daniel

2012-01-01

Previous studies in euryhaline fish have shown that acclimation to hypersaline environments enhances the toxicity of thioether organophosphate and carbamate pesticides. To better understand the potential mechanism of enhanced toxicity, the effects of the organophosphate insecticide phorate were evaluated in coho salmon (Oncorhynchus kisutch) maintained in freshwater (<0.5 g/L salinity) and 32 g/L salinity. The observed 96-h LC50 in freshwater fish (67.34 ± 3.41 μg/L) was significantly reduced to 2.07 ± 0.16 μg/L in hypersaline-acclimated fish. Because organophosphates often require bioactivation to elicit toxicity through acetylcholinesterase (AChE) inhibition, the in vitro biotransformation of phorate was evaluated in coho salmon maintained in different salinities in liver, gills, and olfactory tissues. Phorate sulfoxide was the predominant metabolite in each tissue but rates of formation diminished in a salinity-dependent manner. In contrast, formation of phorate-oxon (gill; olfactory tissues), phorate sulfone (liver), and phorate-oxon sulfoxide (liver; olfactory tissues) was significantly enhanced in fish acclimated to higher salinities. From previous studies, it was expected that phorate and phorate sulfoxide would be less potent AChE inhibitors than phorate-oxon, with phorate-oxon sulfoxide being the most potent of the compounds tested. This trend was confirmed in this study. In summary, these results suggest that differential expression and/or catalytic activities of Phase I enzymes may be involved to enhance phorate oxidative metabolism and subsequent toxicity of phorate to coho salmon under hypersaline conditions. The outcome may be enhanced fish susceptibility to anticholineterase oxon sulfoxides. PMID:21488666

Rearing Mozambique tilapia in tidally-changing salinities: Effects on growth and the growth hormone/insulin-like growth factor I axis.

PubMed

Moorman, Benjamin P; Yamaguchi, Yoko; Lerner, Darren T; Grau, E Gordon; Seale, Andre P

2016-08-01

The growth hormone (GH)/insulin-like growth factor (IGF) axis plays a central role in the regulation of growth in teleosts and has been shown to be affected by acclimation salinity. This study was aimed at characterizing the effects of rearing tilapia, Oreochromis mossambicus, in a tidally-changing salinity on the GH/IGF axis and growth. Tilapia were raised in fresh water (FW), seawater (SW), or in a tidally-changing environment, in which salinity is switched between FW (TF) and SW (TS) every 6h, for 4months. Growth was measured over all time points recorded and fish reared in a tidally-changing environment grew significantly faster than other groups. The levels of circulating growth hormone (GH), insulin-like growth factor I (IGF-I), pituitary GH mRNA, gene expression of IGF-I, IGF-II, and growth hormone receptor 2 (GHR) in the muscle and liver were also determined. Plasma IGF-I was higher in FW and TS than in SW and TF tilapia. Pituitary GH mRNA was higher in TF and TS than in FW and SW tilapia. Gene expression of IGF-I in the liver and of GHR in both the muscle and liver changed between TF and TS fish. Fish growth was positively correlated with GH mRNA expression in the pituitary, and GHR mRNA expression in muscle and liver tissues. Our study indicates that rearing fish under tidally-changing salinities elicits a distinct pattern of endocrine regulation from that observed in fish reared in steady-state conditions, and may provide a new approach to increase tilapia growth rate and study the regulation of growth in euryhaline fish. Copyright © 2016 Elsevier Inc. All rights reserved.

Osmolality/salinity-responsive enhancers (OSREs) control induction of osmoprotective genes in euryhaline fish

PubMed Central

Wang, Xiaodan; Kültz, Dietmar

2017-01-01

Fish respond to salinity stress by transcriptional induction of many genes, but the mechanism of their osmotic regulation is unknown. We developed a reporter assay using cells derived from the brain of the tilapia Oreochromis mossambicus (OmB cells) to identify osmolality/salinity-responsive enhancers (OSREs) in the genes of O. mossambicus. Genomic DNA comprising the regulatory regions of two strongly salinity-induced genes, inositol monophosphatase 1 (IMPA1.1) and myo-inositol phosphate synthase (MIPS), was isolated and analyzed with dual luciferase enhancer trap reporter assays. We identified five sequences (two in IMPA1.1 and three in MIPS) that share a common consensus element (DDKGGAAWWDWWYDNRB), which we named “OSRE1.” Additional OSREs that were less effective in conferring salinity-induced trans-activation and do not match the OSRE1 consensus also were identified in both MIPS and IMPA1.1. Although OSRE1 shares homology with the mammalian osmotic-response element/tonicity-responsive enhancer (ORE/TonE) enhancer, the latter is insufficient to confer osmotic induction in fish. Like other enhancers, OSRE1 trans-activates genes independent of orientation. We conclude that OSRE1 is a cis-regulatory element (CRE) that enhances the hyperosmotic induction of osmoregulated genes in fish. Our study also shows that tailored reporter assays developed for OmB cells facilitate the identification of CREs in fish genomes. Knowledge of the OSRE1 motif allows affinity-purification of the corresponding transcription factor and computational approaches for enhancer screening of fish genomes. Moreover, our study enables targeted inactivation of OSRE1 enhancers, a method superior to gene knockout for functional characterization because it confines impairment of gene function to a specific context (salinity stress) and eliminates pitfalls of constitutive gene knockouts (embryonic lethality, developmental compensation). PMID:28289196

Expression of Key Ion Transporters in the Gill and Esophageal-Gastrointestinal Tract of Euryhaline Mozambique Tilapia Oreochromis mossambicus Acclimated to Fresh Water, Seawater and Hypersaline Water

PubMed Central

Li, Zhengjun; Lui, Eei Yin; Wilson, Jonathan M.; Ip, Yuen Kwong; Lin, Qingsong; Lam, Toong Jin; Lam, Siew Hong

2014-01-01

The ability of euryhaline Mozambique tilapia to tolerate extreme environmental salinities makes it an excellent model for investigating iono-regulation. This study aimed to characterize and fill important information gap of the expression levels of key ion transporters for Na+ and Cl− in the gill and esophageal-gastrointestinal tract of Mozambique tilapia acclimated to freshwater (0 ppt), seawater (30 ppt) and hypersaline (70 ppt) environments. Among the seven genes studied, it was found that nkcc2, nkcc1a, cftr, nka-α1 and nka-α3, were more responsive to salinity challenge than nkcc1b and ncc within the investigated tissues. The ncc expression was restricted to gills of freshwater-acclimated fish while nkcc2 expression was restricted to intestinal segments irrespective of salinity challenge. Among the tissues investigated, gill and posterior intestine were found to be highly responsive to salinity changes, followed by anterior and middle intestine. Both esophagus and stomach displayed significant up-regulation of nka-α1 and nka-α3, but not nkcc isoforms and cftr, in hypersaline-acclimated fish suggesting a response to hypersalinity challenge and involvement of other forms of transporters in iono-regulation. Changes in gene expression levels were partly corroborated by immunohistochemical localization of transport proteins. Apical expression of Ncc was found in Nka-immunoreactive cells in freshwater-acclimated gills while Nkcc co-localized with Nka-immunoreactive cells expressing Cftr apically in seawater- and hypersaline-acclimated gills. In the intestine, Nkcc-stained apical brush border was found in Nka-immunoreactive cells at greater levels under hypersaline conditions. These findings provided new insights into the responsiveness of these genes and tissues under hypersalinity challenge, specifically the posterior intestine being vital for salt absorption and iono-osmoregulation in the Mozambique tilapia; its ability to survive in hypersalinity may be in part related to its ability to up-regulate key ion transporters in the posterior intestine. The findings pave the way for future iono-regulatory studies on the Mozambique tilapia esophageal-gastrointestinal tract. PMID:24498146

Cortisol receptor blockade and seawater adaptation in the euryhaline teleost Fundulus heteroclitus

USGS Publications Warehouse

Marshall, W.S.; Cozzi, R.R.F.; Pelis, Ryan M.; McCormick, S.D.

2005-01-01

To examine the role of cortisol in seawater osmoregulation in a euryhaline teleost, adult killifish were acclimated to brackish water (10???) and RU486 or vehicle was administered orally in peanut oil daily for five days at low (40 mg.kg-1) or high dose (200 mg.kg-1). Fish were transferred to 1.5 x seawater (45???) or to brackish water (control) and sampled at 24 h and 48 h after transfer, when Cl- secretion is upregulated. At 24 h, opercular membrane Cl- secretion rate, as Isc, was increased only in the high dose RU486 group. Stimulation of membranes by 3-isobutyl-1-methylxanthine and cAMP increased Isc in vehicle treated controls but those from RU486-treated animals were unchanged and membranes from brackish water animals showed a decrease in Isc. At 48 h, Isc increased and transepithelial resistance decreased in vehicle and RU486 groups, compared to brackish water controls. Plasma cortisol increased in all groups transferred to high salinity, compared to brackish water controls. RU486 treated animals had higher cortisol levels compared to vehicle controls. Vehicle treated controls had lower cortisol levels than untreated or RU486 treated animals, higher stimulation of Isc, and lower hematocrit at 24 h, beneficial effects attributed to increased caloric intake from the peanut oil vehicle. Chloride cell density was significantly increased in the high dose RU486 group at 48 hours, yet Isc was unchanged, suggesting a decrease in Cl- secretion per cell. Thus cortisol enhances NaCl secretion capacity in chloride cells, likely via glucocorticoid type receptors. ?? 2005 Wiley-Liss, Inc.

Hepatic urea biosynthesis in the euryhaline elasmobranch Carcharhinus leucas.

PubMed

Anderson, W Gary; Good, Jonathan P; Pillans, Richard D; Hazon, Neil; Franklin, Craig E

2005-10-01

Plasma urea levels and hepatic urea production in the euryhaline bull shark, Carcharhinus leucas, acclimated to freshwater and seawater environments were measured. It was found that plasma urea concentration increased with salinity and that this increase was, in part, the result of a significant increase in hepatic production of urea. This study provides direct evidence that hepatic production of urea plays an important role in the osmoregulatory strategy of C. leucas. (c) 2005 Wiley-Liss, Inc.

Genome-wide QTL mapping of saltwater tolerance in sibling species of Anopheles (malaria vector) mosquitoes

PubMed Central

Smith, H A; White, B J; Kundert, P; Cheng, C; Romero-Severson, J; Andolfatto, P; Besansky, N J

2015-01-01

Although freshwater (FW) is the ancestral habitat for larval mosquitoes, multiple species independently evolved the ability to survive in saltwater (SW). Here, we use quantitative trait locus (QTL) mapping to investigate the genetic architecture of osmoregulation in Anopheles mosquitoes, vectors of human malaria. We analyzed 1134 backcross progeny from a cross between the obligate FW species An. coluzzii, and its closely related euryhaline sibling species An. merus. Tests of 2387 markers with Bayesian interval mapping and machine learning (random forests) yielded six genomic regions associated with SW tolerance. Overlap in QTL regions from both approaches enhances confidence in QTL identification. Evidence exists for synergistic as well as disruptive epistasis among loci. Intriguingly, one QTL region containing ion transporters spans the 2Rop chromosomal inversion that distinguishes these species. Rather than a simple trait controlled by one or a few loci, our data are most consistent with a complex, polygenic mode of inheritance. PMID:25920668

Checklist and distribution of ciliates from the family Euplotidae Ehrenberg, 1838 (Protista: Ciliophora: Spirotrichea) in Slovakia, Central Europe.

PubMed

Tirjaková, Eva; Botlíková, Simona; Vďačný, Peter

2015-02-20

A checklist of ciliates from the family Euplotidae recorded in the territory of Slovakia, Central Europe was assembled. Altogether, 11 species belonging to three genera of the family Euplotidae have been reported there: Euplotes alatus, Euplotes charon, Euplotes moebiusi, Euplotoides aediculatus, Euplotoides eurystomus, Euplotoides patella, Euplotoides woodruffi, Euplotopsis affinis, Euplotopsis finki, Euplotopsis muscicola, and Euplotopsis novemcarinata. However, records of the marine species E. alatus and E. charon are doubtful and very likely represent misidentifications of E. moebiusi. Since the euryhaline species E. woodruffi was found for the first time in Slovakia, its morphology is described. Based on the literature data and our own observations, the present checklist is also accompanied with distribution data on the 11 aforementioned species. As concerns ecology, Slovak euplotids typically occurred in freshwater bodies having higher trophic levels. Only two species, E. finki and E. muscicola, were isolated from terrestrial habitats, especially, from mosses, leaf-litter, and decaying wood mass.

A novel method to develop an otolith microchemistry model to determine striped bass habitat use in the San Francisco Estuary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillis, C C; Ostrach, D J; Gras, M

2006-06-14

Otolith Sr/Ca has become a popular tool for hind casting habitat utilization and migration histories of euryhaline fish. It can readily identify habitat shifts of diadromous fish in most systems. Inferring movements of fish within estuarine habitat, however, requires a model of that accounts of the local water chemistry and the response of individual species to that water chemistry, which is poorly understood. Modeling is further complicated by the fact that high marine Sr and Ca concentrations results in a rapid, nonlinear increase in water Sr/Ca and {sup 87}Sr/{sup 86}Sr between fresh and marine waters. Here we demonstrate a novelmore » method for developing a salinity-otolith Sr/Ca model for the purpose of reconstructing striped bass (Morone saxatilis) habitat use in the San Francisco Bay estuary. We used correlated Sr/Ca and {sup 87}Sr/{sup 86}Sr ratios measurements from adult otoliths from striped bass that experienced a range of salinities to infer striped bass otolith Sr/Ca response to changes in salinity and water Sr/Ca ratio. Otolith {sup 87}Sr/{sup 86}Sr can be assumed to accurately record water {sup 87}Sr/{sup 86}Sr because there is no biological fractionation of Sr isotopes. Water {sup 87}Sr/{sup 86}Sr can in turn be used to estimate water salinity based on the mixing of fresh and marine water with known {sup 87}Sr/{sup 86}Sr ratios. The relationship between adjacent analyses on otoliths of Sr/Ca and {sup 87}Sr/{sup 86}Sr by LA-ICP-MS and MC-ICP-MS (r{sup 2} = 0.65, n = 66) is used to predict water salinity from a measured Sr/Ca ratio. The nature of this non-linear model lends itself well to identifying residence in the Delta and to a lesser extent Suisun Bay, but does not do well locating residence within the more saline bays west of Carquinez Strait. An increase in the number of analyses would improve model confidence, but ultimately the precision of the model is limited by the variability in the response of individual fish to water Sr/Ca.« less

Age and Growth of Endangered Smalltooth Sawfish (Pristis pectinata) Verified with LA-ICP-MS Analysis of Vertebrae

PubMed Central

Scharer, Rachel M.; Patterson III, William F.; Carlson, John K.; Poulakis, Gregg R.

2012-01-01

Endangered smalltooth sawfish (Pristis pectinata) were opportunistically sampled in south Florida and aged by counting opaque bands in sectioned vertebrae (n = 15). Small sample size precluded traditional age verification, but fish collected in spring and summer had translucent vertebrae margins, while fish collected in winter had opaque margins. Trends in Sr:Ca measured across vertebrae with laser ablation-inductively coupled plasma-mass spectrometry corresponded well to annual salinity trends observed in sawfish estuarine nursery habitats in south Florida, thus serve as a chemical marker verifying annual formation of opaque bands. Based on that finding and assumptions about mean birth date and timing of opaque band formation, estimated age ranged from 0.4 y for a 0.60 m total length (TL) male to 14.0 y for a 4.35 m TL female. Von Bertalanffy growth parameters computed from size at age data were 4.48 m for L∞, 0.219 y−1for k, and −0.81 y for t0. Results of this study have important implications for sawfish conservation as well as for inferring habitat residency of euryhaline elasmobranchs via chemical analysis of vertebrae. PMID:23082225

Activation of the growth hormone/insulin-like growth factor axis by treatment with 17 alpha-methyltestosterone and seawater rearing in the tilapia, Oreochromis mossambicus.

PubMed

Riley, Larry G; Richman, Nurney H; Hirano, Tetsuya; Gordon Grau, E

2002-07-01

Effects of 17 alpha-methyltestosterone (MT) treatment and environmental salinity on the growth hormone (GH)/insulin-like growth factor (IGF) axis were examined in the euryhaline tilapia, Oreochromis mossambicus. Yolk-sac fry were collected from brood stock in fresh water (FW). After yolk-sac absorption, they were assigned randomly to 1 of 4 groups: FW, MT treatment in FW, SW, and MT treatment in seawater (SW). After 147 days, FW controls had the lowest levels of GH mRNA followed by FW fish treated with MT and SW control fish. Seawater fish fed with a diet containing MT, which grew the fastest, had significantly higher levels of GH mRNA than all the other groups. A significant correlation was observed between GH mRNA and the size of the individual fish. By contrast, plasma GH levels did not vary significantly among the groups. Pituitary GH mRNA levels, plasma IGF-I levels, and fish size varied in a correlated pattern, i.e., SW+MT>FW+MT=SW control>FW control. The tilapia pituitary produces two prolactins (PRLs), PRL(177) and PRL(188). Prolactin(177), but not PRL(188), exhibits growth-promoting actions in FW tilapia. Pituitary mRNA levels of both PRLs were significantly higher in fish reared in FW than those reared in SW. Treatment with MT significantly increased mRNA levels of both PRLs in FW, but had no effect on SW fish. No correlation was seen between plasma PRL levels and growth or between PRL mRNA levels and growth. These results indicate that SW rearing and MT treatment stimulate the GH/IGF-I axis, and suggest that pituitary GH mRNA at this stage of development is a better indicator of growth than plasma levels of GH and IGF-I.

Molecular Characterization of the α-Subunit of Na+/K+ ATPase from the Euryhaline Barnacle Balanus improvisus Reveals Multiple Genes and Differential Expression of Alternative Splice Variants

PubMed Central

Lind, Ulrika; Alm Rosenblad, Magnus; Wrange, Anna-Lisa; Sundell, Kristina S.; Jonsson, Per R.; André, Carl; Havenhand, Jonathan; Blomberg, Anders

2013-01-01

The euryhaline bay barnacle Balanus improvisus has one of the broadest salinity tolerances of any barnacle species. It is able to complete its life cycle in salinities close to freshwater (3 PSU) up to fully marine conditions (35 PSU) and is regarded as one of few truly brackish-water species. Na+/K+ ATPase (NAK) has been shown to be important for osmoregulation when marine organisms are challenged by changing salinities, and we therefore cloned and examined the expression of different NAKs from B. improvisus. We found two main gene variants, NAK1 and NAK2, which were approximately 70% identical at the protein level. The NAK1 mRNA existed in a long and short variant with the encoded proteins differing only by 27 N-terminal amino acids. This N-terminal stretch was coded for by a separate exon, and the two variants of NAK1 mRNAs appeared to be created by alternative splicing. We furthermore showed that the two NAK1 isoforms were differentially expressed in different life stages and in various tissues of adult barnacle, i.e the long isoform was predominant in cyprids and in adult cirri. In barnacle cyprid larvae that were exposed to a combination of different salinities and pCO2 levels, the expression of the long NAK1 mRNA increased relative to the short in low salinities. We suggest that the alternatively spliced long variant of the Nak1 protein might be of importance for osmoregulation in B. improvisus in low salinity conditions. PMID:24130836

Ontogenetic changes in color vision in the milkfish (Chanos chanos Forsskål, 1775).

PubMed

Chang, Chia-Hao; Chiao, Chuan-Chin; Yan, Hong Young

2009-05-01

The milkfish (Chanos chanos Forsskål, 1775) is a euryhaline fish widely distributed in tropical and subtropical Indo-Pacific waters. It is unique in having in the cephalic region adipose eyelid tissue that begins to develop in the larval stage and is completely formed by the Juvenile stage. The formation of the adipose eyelids coincides with the onset of active swimming ability. Larval and juvenile milkfish have different dietary modes and habitats. This study was aimed to investigate ontogenetic changes in color perception ability with the use of microspectrophotometry (MSP). Larval milkfish had rod cells and red, green, blue, and violet cone cells, while juvenile milkfish lost the violet cone cells, and the blue cones shifted to shorter wavelengths. Histological sections showed the presence of cone cells of the single type (but no double or twin types) in the retina, which implies that the milkfish may not have polarized vision.

Transcriptomic Analysis of Metabolic Pathways in Milkfish That Respond to Salinity and Temperature Changes.

PubMed

Hu, Yau-Chung; Kang, Chao-Kai; Tang, Cheng-Hao; Lee, Tsung-Han

2015-01-01

Milkfish (Chanos chanos), an important marine aquaculture species in southern Taiwan, show considerable euryhalinity but have low tolerance to sudden drops in water temperatures in winter. Here, we used high throughput next-generation sequencing (NGS) to identify molecular and biological processes involved in the responses to environmental changes. Preliminary tests revealed that seawater (SW)-acclimated milkfish tolerated lower temperatures than the fresh water (FW)-acclimated group. Although FW- and SW-acclimated milkfish have different levels of tolerance for hypothermal stress, to date, the molecular physiological basis of this difference has not been elucidated. Here, we performed a next-generation sequence analysis of mRNAs from four groups of milkfish. We obtained 29669 unigenes with an average length of approximately 1936 base pairs. Gene ontology (GO) analysis was performed after gene annotation. A large number of genes for molecular regulation were identified through a transcriptomic comparison in a KEGG analysis. Basal metabolic pathways involved in hypothermal tolerance, such as glycolysis, fatty acid metabolism, amino acid catabolism and oxidative phosphorylation, were analyzed using PathVisio and Cytoscape software. Our results indicate that in response to hypothermal stress, genes for oxidative phosphorylation, e.g., succinate dehydrogenase, were more highly up-regulated in SW than FW fish. Moreover, SW and FW milkfish used different strategies when exposed to hypothermal stress: SW milkfish up-regulated oxidative phosphorylation and catabolism genes to produce more energy budget, whereas FW milkfish down-regulated genes related to basal metabolism to reduce energy loss.

Transcriptomic Analysis of Metabolic Pathways in Milkfish That Respond to Salinity and Temperature Changes

PubMed Central

Hu, Yau-Chung; Kang, Chao-Kai; Tang, Cheng-Hao; Lee, Tsung-Han

2015-01-01

Milkfish (Chanos chanos), an important marine aquaculture species in southern Taiwan, show considerable euryhalinity but have low tolerance to sudden drops in water temperatures in winter. Here, we used high throughput next-generation sequencing (NGS) to identify molecular and biological processes involved in the responses to environmental changes. Preliminary tests revealed that seawater (SW)-acclimated milkfish tolerated lower temperatures than the fresh water (FW)-acclimated group. Although FW- and SW-acclimated milkfish have different levels of tolerance for hypothermal stress, to date, the molecular physiological basis of this difference has not been elucidated. Here, we performed a next-generation sequence analysis of mRNAs from four groups of milkfish. We obtained 29669 unigenes with an average length of approximately 1936 base pairs. Gene ontology (GO) analysis was performed after gene annotation. A large number of genes for molecular regulation were identified through a transcriptomic comparison in a KEGG analysis. Basal metabolic pathways involved in hypothermal tolerance, such as glycolysis, fatty acid metabolism, amino acid catabolism and oxidative phosphorylation, were analyzed using PathVisio and Cytoscape software. Our results indicate that in response to hypothermal stress, genes for oxidative phosphorylation, e.g., succinate dehydrogenase, were more highly up-regulated in SW than FW fish. Moreover, SW and FW milkfish used different strategies when exposed to hypothermal stress: SW milkfish up-regulated oxidative phosphorylation and catabolism genes to produce more energy budget, whereas FW milkfish down-regulated genes related to basal metabolism to reduce energy loss. PMID:26263550

Salinity dependent Na+-K+ATPase activity in gills of the euryhaline crab Chasmagnathus granulata.

PubMed

Schleich, C E; Goldemberg, L A; López Mañanes, A A

2001-09-01

The occurrence and response of Na+-K+ATPase specific activity to environmental salinity changes were studied in gill extracts of all of the gills of the euryhaline crab Chasmagnathus granulata from Mar Chiquita coastal lagoon (Buenos Aires Province, Argentina). All of the gills exhibited a salinity dependent Na+-K+ATPase activity, although the pattern of response to environmental salinity was different among gills. As described in other euryhaline crabs highest Na+-K+ATPase specific activity was found in posterior gills (6 to 8), which, with exception of gill 6, increased upon acclimation to reduced salinity. However, a high increase of activity also occurred in anterior gills (1 to 5) in diluted media. Furthermore, both short and long term differential changes of Na+-K+ATPase activity occurred among the gills after the transfer of crabs to reduced salinity. The fact that variations of Na+-K+ATPase activity in the gills were concomitant with the transition from osmoconformity to ionoregulation suggests that this enzyme is a component of the branchial ionoregulatory mechanisms at the biochemical level in this crab.

[Effect of temperature and salinity on intrinsic increasing rate of Moina mongolica Daddy (Cladocera: Moinidae) population].

PubMed

Wang, Y; He, Z

2001-02-01

The intrinsic increasing rate of Moina mongolica Daddy, a euryhaline cladocera species isolated from inland brackish lakes of northwestern China, was studied at 20 degrees C-33 degrees C and 5-40 ppt, respectively. The results showed that its intrinsic increasing rate (rm) increased with increasing temperature from 20 degrees C-30 degrees C, and sharply dropped with further increasing temperature up to 33 degrees C. The rm of M. mongolica was relatively high at low salinity, the highest at 10 ppt, but no significant difference at 20-40 ppt. Therefore, 25 degrees C-30 degrees C and 10 ppt could be optimal for the development of M. mongolica population, and its increasing potential would not be affected significantly by rearing this cladocera species in seawater for a long period.

A novel variant of aquaporin 3 is expressed in killifish (Fundulus heteroclitus) intestine

PubMed Central

Jung, Dawoon; Adamo, Meredith A.; Lehman, Rebecca M.; Barnaby, Roxanna; Jackson, Craig E.; Jackson, Brian P.; Shaw, Joseph R.; Stanton, Bruce A.

2015-01-01

Killifish (Fundulus heteroclitus) are euryhaline teleosts that are widely used in environmental and toxicological studies, and they are tolerant to arsenic, in part due to very low assimilation of arsenic from the environment. The mechanism of arsenic uptake by the intestine, a major route of arsenic uptake in humans is unknown. Thus, the goal of this study was to determine if aquaglyceroporins (AQP), which transport water and other small molecules including arsenite across cell membranes, are expressed in the killifish intestine, and whether AQP expression is affected by osmotic stress. Through RT-PCR and sequence analysis of PCR amplicons, we demonstrated that the intestine expresses kfAQP3a and kfAQP3b, two previously identified variants, and also identified a novel variant of killifish AQP3 (kfAQP3c) in the intestine. The variants likely represent alternate splice forms. A BLAST search of the F. heteroclitus reference genome revealed that the AQP3 gene resides on a single locus, while an alignment of the AQP3 sequence among 384 individuals from eight population ranging from Rhode Island to North Carolina revealed that its coding sequence was remarkably conserved with no fixed polymorphism residing in the region that distinguishes these variants. We further demonstrate that the novel variant transports arsenite into HEK293T cells. Whereas kfAQP3a, which does not transport arsenite, was expressed in both freshwater (FW) and saltwater (SW) acclimated fish, kfAQP3b, an arsenic transporter, was expressed only in FW acclimated fish, and kfAQP3c was expressed only in SW acclimated fish. Thus, we have identified a novel, putative splice variant of kfAQP3, kfAQP3c, which transports arsenic and is expressed only in SW acclimated fish. PMID:25766383

Fish diversity and its conservation in major wetlands of Mysore.

PubMed

Prasad, A G Devi; Venkataramana, G V; Thomas, Mathew

2009-09-01

The paper highlights the fish diversity in major wetlands of Mysore district, Karnataka, India and its conservation status. Forty-five species of fishes belonging to 15 families, 31 genera have been identified. Fish species belonging to genus Puntius were more common in many of these lakes. However it was observed that the fish diversity was decreasing since last two years unprecedently mainly due to manifold human activities. Fish diversity in the lakes is becoming rare and about seven species were identified as endangered. Out of the 45 identified fishes, six fish species were identified as threatened species. Tork hudree, also known as Deccan mahseer and seven other species were identified as vulnerable fish species. Though there were 40 species of fish endemic to this region, their number decreased with introduction of more exotic species. Conservation of endemic fishes, propagation of endangered and threatened fishes should be therefore, undertaken to preserve and protect fish diversity in the wetlands of Mysore district.

Establishment of two invasive crustaceans (Copepoda: Harpacticoida) on the nearshore sands of Lake Michigan

USGS Publications Warehouse

Horvath, Thomas G.; Whitman, Richard L.; Last, Laurel L.

2001-01-01

Benthic copepods (Copepoda: Harpacticoida) in the nearshore sediments of southern Lake Michigan appear to be dominated by two new invasive species. We report the first occurrence in North America of Schizopera borutzkyi Montschenko, a native to the Danube River delta, and Heteropsyllus nr. nunni, likely a new species that is morphologically similar to the marine species Heteropsyllus nunni and represents the first occurrence of this genus in freshwater. Schizopera borutzkyi is a euryhaline species occurring in shallow sands in its native habitat and in deeper sands (6-15 m) in southern Lake Michigan. Based on the absence of these species from previous studies, we suggest that they are recent introductions. Heteropsyllus nr. nunni dominated (55-100%) the harpacticoid abundance to depths of 9 m, but S. borutzkyi comprised 75% of the harpacticoid abundance at 15 m. Native harpacticoids were always greatly outnumbered by invasive harpacticoids in our samples, which suggests that the natives are being replaced rapidly or that the invasive species are finding unused resources. The ecological implications of these introductions are not known, but these invasions may represent continued 'invasional meltdown' in Lake Michigan.

Ichthyobodo salmonis sp. n. (Ichthyobodonidae, Kinetoplastida), an euryhaline ectoparasite infecting Atlantic salmon (Salmo salar L.)

PubMed Central

ISAKSEN, TROND E.; KARLSBAKK, EGIL; WATANABE, KUNINORI; NYLUND, ARE

2011-01-01

SUMMARY Phylogenetic analyses of SSU rDNA sequences have previously revealed the existence of 2 Ichthyobodo species able to infect Atlantic salmon (Salmo salar L.). Ichthyobodo necator sensu stricto (s.s.) is assumed to be a freshwater parasite, while a genetically distinct but undescribed species, Ichthyobodo sp. II sensu Todal et al. (2004) have been detected on Atlantic salmon in both fresh- and seawater. In the present study a morphological description of Ichthyobodo sp. II from the gills of salmon reared in fresh-, brackish- and seawater is presented, using both light- and electron microscopy. Comparative morphometry show that Ichthyobodo sp. II from both freshwater and seawater displays a different cell shape, and is significantly smaller than I. necator s.s. Also, ultrastructural characteristics distinguish these two species, notably differences in the attachment region and the presence of spine-like surface projections in Ichthyobodo sp. II. Based on both unique SSU rDNA sequences and morphological characteristics, we conclude that Ichthyobodo sp. II. represents a novel species for which we propose the name Ichthyobodo salmonis sp. n. PMID:21756424

Benthic foraminiferal and organic matter compounds as proxies of environmental quality in a tropical coastal lagoon: The Itaipu lagoon (Brazil).

PubMed

Raposo, Débora; Clemente, Iara; Figueiredo, Marcos; Vilar, Amanda; Lorini, Maria Lucia; Frontalini, Fabrizio; Martins, Virgínia; Belart, Pierre; Fontana, Luiz; Habib, Renan; Laut, Lazaro

2018-04-01

Lagoons in the southeast coast of Brazil have experienced eutrophication due to the exponential increase of human population and sewage discharges. Living benthic foraminifera have demonstrated to be good bioindicators of such impacts. This study aims to evaluate the organic matter accumulation effects on the foraminiferal distribution in the Itaipu lagoon (Brazil). On the basis of the biotic and abiotic analyses, three sectors are identified. The Sector I, an inner area, is characterized by high dissolved oxygen values and foraminiferal species with preference for marine conditions, demonstrating the sea influence. The Sector II, in the mangrove margins, is associated to sandy sediment and biopolymers and mainly represented by euryhaline species. The Sector III is marked by low density or absence of living foraminifera and corresponds to a low quality organic matter enriched area (North, Southwest and Centre). Copyright © 2018 Elsevier Ltd. All rights reserved.

Reciprocal osmotic challenges reveal mechanisms of divergence in phenotypic plasticity in the killifish Fundulus heteroclitus.

PubMed

Brennan, Reid S; Galvez, Fernando; Whitehead, Andrew

2015-04-15

The killifish Fundulus heteroclitus is an estuarine species with broad physiological plasticity, enabling acclimation to diverse stressors. Previous work suggests that freshwater populations expanded their physiology to accommodate low salinity environments; however, it is unknown whether this compromises their tolerance to high salinity. We used a comparative approach to investigate the mechanisms of a derived freshwater phenotype and the fate of an ancestral euryhaline phenotype after invasion of a freshwater environment. We compared physiological and transcriptomic responses to high- and low-salinity stress in fresh and brackish water populations and found an enhanced plasticity to low salinity in the freshwater population coupled with a reduced ability to acclimate to high salinity. Transcriptomic data identified genes with a conserved common response, a conserved salinity-dependent response and responses associated with population divergence. Conserved common acclimation responses revealed stress responses and alterations in cell-cycle regulation as important mechanisms in the general osmotic response. Salinity-specific responses included the regulation of genes involved in ion transport, intracellular calcium, energetic processes and cellular remodeling. Genes diverged between populations were primarily those showing salinity-specific expression and included those regulating polyamine homeostasis and the cell cycle. Additionally, when populations were matched with their native salinity, expression patterns were consistent with the concept of 'transcriptomic resilience', suggesting local adaptation. These findings provide insight into the fate of a plastic phenotype after a shift in environmental salinity and help to reveal mechanisms allowing for euryhalinity. © 2015. Published by The Company of Biologists Ltd.

An annotated list of fish parasites (Isopoda, Copepoda, Monogenea, Digenea, Cestoda, Nematoda) collected from Snappers and Bream (Lutjanidae, Nemipteridae, Caesionidae) in New Caledonia confirms high parasite biodiversity on coral reef fish

PubMed Central

2012-01-01

Background Coral reefs are areas of maximum biodiversity, but the parasites of coral reef fishes, and especially their species richness, are not well known. Over an 8-year period, parasites were collected from 24 species of Lutjanidae, Nemipteridae and Caesionidae off New Caledonia, South Pacific. Results Host-parasite and parasite-host lists are provided, with a total of 207 host-parasite combinations and 58 parasite species identified at the species level, with 27 new host records. Results are presented for isopods, copepods, monogeneans, digeneans, cestodes and nematodes. When results are restricted to well-sampled reef fish species (sample size > 30), the number of host-parasite combinations is 20–25 per fish species, and the number of parasites identified at the species level is 9–13 per fish species. Lutjanids include reef-associated fish and deeper sea fish from the outer slopes of the coral reef: fish from both milieus were compared. Surprisingly, parasite biodiversity was higher in deeper sea fish than in reef fish (host-parasite combinations: 12.50 vs 10.13, number of species per fish 3.75 vs 3.00); however, we identified four biases which diminish the validity of this comparison. Finally, these results and previously published results allow us to propose a generalization of parasite biodiversity for four major families of reef-associated fishes (Lutjanidae, Nemipteridae, Serranidae and Lethrinidae): well-sampled fish have a mean of 20 host-parasite combinations per fish species, and the number of parasites identified at the species level is 10 per fish species. Conclusions Since all precautions have been taken to minimize taxon numbers, it is safe to affirm than the number of fish parasites is at least ten times the number of fish species in coral reefs, for species of similar size or larger than the species in the four families studied; this is a major improvement to our estimate of biodiversity in coral reefs. Our results suggest that extinction of a coral reef fish species would eventually result in the coextinction of at least ten species of parasites. PMID:22947621

An annotated list of fish parasites (Isopoda, Copepoda, Monogenea, Digenea, Cestoda, Nematoda) collected from Snappers and Bream (Lutjanidae, Nemipteridae, Caesionidae) in New Caledonia confirms high parasite biodiversity on coral reef fish.

PubMed

Justine, Jean-Lou; Beveridge, Ian; Boxshall, Geoffrey A; Bray, Rodney A; Miller, Terrence L; Moravec, František; Trilles, Jean-Paul; Whittington, Ian D

2012-09-04

Coral reefs are areas of maximum biodiversity, but the parasites of coral reef fishes, and especially their species richness, are not well known. Over an 8-year period, parasites were collected from 24 species of Lutjanidae, Nemipteridae and Caesionidae off New Caledonia, South Pacific. Host-parasite and parasite-host lists are provided, with a total of 207 host-parasite combinations and 58 parasite species identified at the species level, with 27 new host records. Results are presented for isopods, copepods, monogeneans, digeneans, cestodes and nematodes. When results are restricted to well-sampled reef fish species (sample size > 30), the number of host-parasite combinations is 20-25 per fish species, and the number of parasites identified at the species level is 9-13 per fish species. Lutjanids include reef-associated fish and deeper sea fish from the outer slopes of the coral reef: fish from both milieus were compared. Surprisingly, parasite biodiversity was higher in deeper sea fish than in reef fish (host-parasite combinations: 12.50 vs 10.13, number of species per fish 3.75 vs 3.00); however, we identified four biases which diminish the validity of this comparison. Finally, these results and previously published results allow us to propose a generalization of parasite biodiversity for four major families of reef-associated fishes (Lutjanidae, Nemipteridae, Serranidae and Lethrinidae): well-sampled fish have a mean of 20 host-parasite combinations per fish species, and the number of parasites identified at the species level is 10 per fish species. Since all precautions have been taken to minimize taxon numbers, it is safe to affirm than the number of fish parasites is at least ten times the number of fish species in coral reefs, for species of similar size or larger than the species in the four families studied; this is a major improvement to our estimate of biodiversity in coral reefs. Our results suggest that extinction of a coral reef fish species would eventually result in the coextinction of at least ten species of parasites.

Marine, freshwater and aerially acclimated mangrove rivulus (Kryptolebias marmoratus) use different strategies for cutaneous ammonia excretion

PubMed Central

Cooper, Christopher A.; Wilson, Jonathan M.

2013-01-01

Rhesus (Rh) glycoproteins are ammonia gas (NH3) channels known to be involved in ammonia transport in animals. Because of the different osmoregulatory and ionoregulatory challenges faced by teleost fishes in marine and freshwater (FW) environments, we hypothesized that ammonia excretion strategies would differ between environments. Also, we hypothesized that cutaneous NH3 volatilization in air-acclimated fish is facilitated by base secretion. To test these hypotheses, we used the skin of the euryhaline amphibious mangrove rivulus (Kryptolebias marmoratus). The skin excretes ammonia and expresses Rh glycoproteins. Serosal-to-mucosal cutaneous ammonia flux was saturable (0–16 mmol/l ammonia, Km of 6.42 mmol/l). In FW, ammonia excretion increased in response to low mucosal pH but decreased with pharmacological inhibition of Na+/H+ exchangers (NHE) and H+ ATPase. Conversely, in brackish water (BW), lowering the mucosal pH significantly decreased ammonia excretion. Inhibitors of NHE also decreased ammonia excretion in BW fish. Immunofluorescence microscopy demonstrated that both the Rh isoform, Rhcg1, and NHE3 proteins colocalized in Na+/K+ ATPase expressing mitochondrion-rich cells in the gills, kidney, and skin. We propose that the mechanisms of cutaneous ammonia excretion in FW K. marmoratus are consistent with the model for branchial ammonia excretion in FW teleost fish. NH4+ excretion appeared to play a stronger role in BW. NH4+ excretion in BW may be facilitated by apical NHE and/or diffuse through paracellular pathways. In aerially acclimated fish, inhibition of NHE and H+ ATPase, but not the Cl−/HCO3− exchanger, significantly affected cutaneous surface pH, suggesting that direct base excretion is not critical for NH3 volatilization. Overall, K. marmoratus use different strategies for excreting ammonia in three different environments, FW, BW, and air, and Rh glycoproteins and NHE are integral to all. PMID:23389109

Relations between introduced fish and environmental conditions at large geographic scales

USGS Publications Warehouse

Meador, M.R.; Brown, L.R.; Short, T.

2003-01-01

Data collected from 20 major river basins between 1993 and 1995 as part of the US Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) Program were analyzed to assess patterns in introduced and native fish species richness and abundance relative to watershed characteristics and stream physicochemistry. Sites (N = 157) were divided into three regions-northeast, southeast, and west- to account for major longitudinal differences in precipitation/runoff and latitudinal limits of glaciation that affect zoogeographic patterns in fish communities. Common carp (Cyprinus carpio) and largemouth bass (Micropterus salmoides) were the most frequently collected introduced fish species across all river basins combined. Based on the percentage of introduced fish species, the fish communities most altered by the presence of introduced fish occurred in the western and northeastern parts of the US. Native fish species richness was not an indicator of introduced fish species richness for any of the three regions. However, in the west, introduced fish species richness was an indicator of total fish species richness and the abundance of introduced fish was negatively related to native fish species richness. Some relations between introduced fish species and environmental conditions were common between regions. Increased introduced fish species richness was related to increased population density in the northeast and southeast; increased total nitrogen in the northeast and west; and increased total phosphorous and water temperature in the southeast and west. These results suggest that introduced fish species tend to be associated with disturbance at large geographic scales, though specific relations may vary regionally. ?? 2003 Elsevier Science Ltd. All rights reserved.

Molecular characterisation and expression of parathyroid hormone-related protein in the caudal neurosecretory system of the euryhaline flounder, Platichthys flesus.

PubMed

Lu, Weiqun; Jin, Yingying; Xu, Jinling; Greenwood, Michael P; Balment, Richard J

2017-08-01

Parathyroid hormone-related protein (PTHrP) is a hypercalcemic factor in fish, but the source of circulating PTHrP remains unclear. In this study investigation of the caudal neurosecretory system (CNSS), considered one of major sources of PTHrP in fish, provided valuable insights into this regulatory system. We report pthrpa and pthrpb gene cloning, characterization, expression, and responses to low salinity and hypocalcemia challenge in flounder. The pthrpa and pthrpb precursors, isolated from a European flounder CNSS library, consist of 166 and 192 amino acid residues, respectively, with an overall homology of approximately 59.2%. Both precursors contain a signal peptide and a mature peptide with cleavage and amidation sites. The flounder PTHrPA and PTHrPB peptides share only 41% sequence identity with human PTHrPA. Quantitative PCR analysis demonstrated that the bone and bladder, are respectively major sites of pthrpa and pthrpb expression in flounder. Urophysectomy confirmed the CNSS as a likely contributor to circulating PTHrP peptides. There were no significant differences in CNSS pthrpa and pthrpb mRNA expression or plasma PTHrP levels between seawater (SW) and freshwater (FW)-adapted fish, though plasma total calcium concentrations were higher in FW animals. The intraperitonial administration of EGTA rapidly induced hypocalcemia and concomitant elevation in plasma PTHrP accompanied by increases in both pthrpa and pthrpb expression in the CNSS. Together, these findings support an evolutionary conserved role for PTHrP in the endocrine regulation of calcium. Copyright © 2017 Elsevier Inc. All rights reserved.

Targeting Abundant Fish Stocks while Avoiding Overfished Species: Video and Fishing Surveys to Inform Management after Long-Term Fishery Closures

PubMed Central

2016-01-01

Historically, it has been difficult to balance conservation goals and yield objectives when managing multispecies fisheries that include stocks with various vulnerabilities to fishing. As managers try to maximize yield in mixed-stock fisheries, exploitation rates can lead to less productive stocks becoming overfished. In the late 1990s, population declines of several U.S. West Coast groundfish species caused the U.S. Pacific Fishery Management Council to create coast-wide fishery closures, known as Rockfish Conservation Areas, to rebuild overfished species. The fishery closures and other management measures successfully reduced fishing mortality of these species, but constrained fishing opportunities on abundant stocks. Restrictive regulations also caused the unintended consequence of reducing fishery-dependent data available to assess population status of fished species. As stocks rebuild, managers are faced with the challenge of increasing fishing opportunities while minimizing fishing mortality on rebuilding species. We designed a camera system to evaluate fishes in coastal habitats and used experimental gear and fishing techniques paired with video surveys to determine if abundant species could be caught in rocky habitats with minimal catches of co-occurring rebuilding species. We fished a total of 58 days and completed 741 sets with vertical hook-and-line fishing gear. We also conducted 299 video surveys in the same locations where fishing occurred. Comparison of fishing and stereo-video surveys indicated that fishermen could fish with modified hook-and-line gear to catch abundant species while limiting bycatch of rebuilding species. As populations of overfished species continue to recover along the U.S. West Coast, it is important to improve data collection, and video and fishing surveys may be key to assessing species that occur in rocky habitats. PMID:28002499

Targeting Abundant Fish Stocks while Avoiding Overfished Species: Video and Fishing Surveys to Inform Management after Long-Term Fishery Closures.

PubMed

Starr, Richard M; Gleason, Mary G; Marks, Corina I; Kline, Donna; Rienecke, Steve; Denney, Christian; Tagini, Anne; Field, John C

2016-01-01

Historically, it has been difficult to balance conservation goals and yield objectives when managing multispecies fisheries that include stocks with various vulnerabilities to fishing. As managers try to maximize yield in mixed-stock fisheries, exploitation rates can lead to less productive stocks becoming overfished. In the late 1990s, population declines of several U.S. West Coast groundfish species caused the U.S. Pacific Fishery Management Council to create coast-wide fishery closures, known as Rockfish Conservation Areas, to rebuild overfished species. The fishery closures and other management measures successfully reduced fishing mortality of these species, but constrained fishing opportunities on abundant stocks. Restrictive regulations also caused the unintended consequence of reducing fishery-dependent data available to assess population status of fished species. As stocks rebuild, managers are faced with the challenge of increasing fishing opportunities while minimizing fishing mortality on rebuilding species. We designed a camera system to evaluate fishes in coastal habitats and used experimental gear and fishing techniques paired with video surveys to determine if abundant species could be caught in rocky habitats with minimal catches of co-occurring rebuilding species. We fished a total of 58 days and completed 741 sets with vertical hook-and-line fishing gear. We also conducted 299 video surveys in the same locations where fishing occurred. Comparison of fishing and stereo-video surveys indicated that fishermen could fish with modified hook-and-line gear to catch abundant species while limiting bycatch of rebuilding species. As populations of overfished species continue to recover along the U.S. West Coast, it is important to improve data collection, and video and fishing surveys may be key to assessing species that occur in rocky habitats.

Na⁺/K⁺-ATPase α1 mRNA expression in the gill and rectal gland of the Atlantic stingray, Dasyatis sabina, following acclimation to increased salinity.

PubMed

Evans, Andrew N; Lambert, Faith N

2015-06-05

The salt-secreting rectal gland plays a major role in elasmobranch osmoregulation, facilitating ion balance in hyperosmotic environments in a manner analogous to the teleost gill. Several studies have examined the central role of the sodium pump Na(+)/K(+)-ATPase in osmoregulatory tissues of euryhaline elasmobranch species, including regulation of Na(+)/K(+)-ATPase activity and abundance in response to salinity acclimation. However, while the transcriptional regulation of Na(+)/K(+)-ATPase in the teleost gill has been well documented the potential for mRNA regulation to facilitate rectal gland plasticity during salinity acclimation in elasmobranchs has not been examined. Therefore, in this study we acclimated Atlantic stingrays, Dasyatis sabina (Lesueur) from 11 to 34 ppt salinity over 3 days, and examined changes in plasma components as well as gill and rectal gland Na(+)/K(+)-ATPase α1 (atp1a1) mRNA expression. Acclimation to increased salinity did not affect hematocrit but resulted in significant increases in plasma osmolality, chloride and urea. Rectal gland atp1a1 mRNA expression was higher in 34 ppt-acclimated D. sabina vs. There was no significant change in gill atp1a1 mRNA expression, however mRNA expression of this gene in the gill and rectal gland were negatively correlated. This study demonstrates regulation of atp1a1 in the elasmobranch salt-secreting gland in response to salinity acclimation and a negative relationship between rectal gland and gill atp1a1 expression. These results support the hypothesis that the gill and rectal gland play opposing roles in ion balance with the gill potentially facilitating ion uptake in hypoosmotic environments. Future studies should further examine this possibility as well as potential differences in the regulation of Na(+)/K(+)-ATPase gene expression between euryhaline and stenohaline elasmobranch species.

Branchial Na+:K+:2Cl− cotransporter 1 and Na+/K+-ATPase α-subunit in a brackish water-type ionocyte of the euryhaline freshwater white-rimmed stingray, Himantura signifer

PubMed Central

Ip, Yuen K.; Hiong, Kum C.; Wong, Samuel Z. H.; Ching, Biyun; Chen, Xiu L.; Soh, Melody M. L.; Chng, You R.; Ong, Jasmine L. Y.; Wilson, Jonathan M.; Chew, Shit F.

2013-01-01

Himantura signifer is a freshwater stingray which inhabits rivers in Southeast Asia. It can survive in brackish water but not seawater. In brackish water, it becomes partially ureosmotic, but how it maintains its plasma hypoionic to the external medium is enigmatic because of the lack of a rectal gland. Here, we report for the first time the expression of Na+:K+:2Cl− cotransporter 1 (nkcc1) in the gills of freshwaterH. signifer, and its moderate up-regulation (~2-fold) in response to brackish water (salinity 20) acclimation. The absence of the Ste20-related proline-alanine-rich kinase and oxidation stress response kinase 1 interaction site from the N-terminus of H. signifer Nkcc1 suggested that it might not be effectively activated by stress kinases in response to salinity changes as in more euryhaline teleosts. The increased activity of Nkcc1 during salt excretion in brackish water would lead to an influx of Na+ into ionocytes, and the maintenance of intracellular Na+ homeostasis would need the cooperation of Na+/K+-ATPase (Nka). We demonstrated for the first time the expression of nkaα1, nkaα2 and nkaα3 in the gills of H. signifer, and the up-regulation of the mRNA expression of nkaα3 and the overall protein abundance of Nkaα in response to acclimation to brackish water. Immunofluorescence microscopy revealed the presence of a sub-type of ionocyte, co-expressing Nkcc1 and Nkaα, near the base of the secondary lamellae in the gills of H. signifer acclimated to brackish water, but this type of ionocyte was absent from the gills of fish kept in fresh water. Hence, there could be a change in the function of the gills of H. signifer from salt absorption to salt excretion during brackish water acclimation in the absence of a functioning rectal gland. PMID:24339817

Population Genomics of the Euryhaline Teleost Poecilia latipinna

PubMed Central

Hoover, D.; Travis, J.; Oleksiak, M. F.; Crawford, D. L.

2015-01-01

Global climate change and increases in sea levels will affect coastal marine communities. The conservation of these ecologically important areas will be a challenge because of their wide geographic distribution, ecological diversity and species richness. To address this problem, we need to better understand how the genetic variation of the species in these communities is distributed within local populations, among populations and between distant regions. In this study we apply genotyping by sequencing (GBS) and examine 955 SNPs to determine Sailfin molly (Poecilia latipinna) genetic diversity among three geographically close mangrove salt marsh flats in the Florida Keys compared to populations in southern and northern Florida. The questions we are asking are whether there is sufficient genetic variation among isolated estuarine fish within populations and whether there are significant divergences among populations. Additionally, we want to know if GBS approaches agree with previous studies using more traditional molecular approaches. We are able to identify large genetic diversity within each saltmarsh community (π ≈ 36%). Additionally, among the Florida Key populations and the mainland or between southern and northern Florida regions, there are significant differences in allele frequencies seen in population structure and evolutionary relationships among individuals. Surprisingly, even though the cumulative FST value using all 955 SNPs within the three Florida Key populations is small, there are 29 loci with significant FST values, and 11 of these were outliers suggestive of adaptive divergence. These data suggest that among the salt marsh flats surveyed here, there is significant genetic diversity within each population and small but significant differences among populations. Much of the genetic variation within and among populations found here with GBS is very similar to previous studies using allozymes and microsatellites. However, the meaningful difference between GBS and these previous measures of genetic diversity is the number of loci examined, which allows more precise delineations of population structure as well as facilitates identifying loci with excessive FST values that could indicate adaptive divergence. PMID:26335684

Population Genomics of the Euryhaline Teleost Poecilia latipinna.

PubMed

Nunez, J C B; Seale, T P; Fraser, M A; Burton, T L; Fortson, T N; Hoover, D; Travis, J; Oleksiak, M F; Crawford, D L

2015-01-01

Global climate change and increases in sea levels will affect coastal marine communities. The conservation of these ecologically important areas will be a challenge because of their wide geographic distribution, ecological diversity and species richness. To address this problem, we need to better understand how the genetic variation of the species in these communities is distributed within local populations, among populations and between distant regions. In this study we apply genotyping by sequencing (GBS) and examine 955 SNPs to determine Sailfin molly (Poecilia latipinna) genetic diversity among three geographically close mangrove salt marsh flats in the Florida Keys compared to populations in southern and northern Florida. The questions we are asking are whether there is sufficient genetic variation among isolated estuarine fish within populations and whether there are significant divergences among populations. Additionally, we want to know if GBS approaches agree with previous studies using more traditional molecular approaches. We are able to identify large genetic diversity within each saltmarsh community (π ≈ 36%). Additionally, among the Florida Key populations and the mainland or between southern and northern Florida regions, there are significant differences in allele frequencies seen in population structure and evolutionary relationships among individuals. Surprisingly, even though the cumulative FST value using all 955 SNPs within the three Florida Key populations is small, there are 29 loci with significant FST values, and 11 of these were outliers suggestive of adaptive divergence. These data suggest that among the salt marsh flats surveyed here, there is significant genetic diversity within each population and small but significant differences among populations. Much of the genetic variation within and among populations found here with GBS is very similar to previous studies using allozymes and microsatellites. However, the meaningful difference between GBS and these previous measures of genetic diversity is the number of loci examined, which allows more precise delineations of population structure as well as facilitates identifying loci with excessive FST values that could indicate adaptive divergence.

Parasite communities of a fish assemblage from the intertidal rocky zone of central Chile: similarity and host specificity between temporal and resident fish.

PubMed

Muñoz, G; Cortés, Y

2009-09-01

The different species of a fish assemblage can, to some extent, be similar in terms of their parasite communities, which can be associated with certain ecological host traits. This study compared the parasite community descriptors between temporal and resident fish species composing an intertidal assemblage from central Chile. Host specificity and similarity indices of parasite communities among the fish species were also considered. A total of 1097 fish representing 14 species were collected during spring and summer of 2 consecutive years. A total spectrum of 40 parasite species was found, of which copepods and trematodes were the commonest. Congeneric fish species had the highest similarities in their parasite communities. Based on a cluster analysis, using only some fish species, no group was distinguished using abundance or prevalence of parasites, because 50% of parasite species had high host specificity and only few of them were shared among fish species. Adult parasites showed high host specificity and were found mainly in resident intertidal fish, whereas the temporal fish had parasites with different degrees of specificity. Consequently, resident intertidal fish were characterized by their own parasite species, meaning that their transmissions might be restricted to the intertidal zone.

Methylmercury in fish from the southern Baltic Sea and coastal lagoons as a function of species, size, and region.

PubMed

Polak-Juszczak, Lucyna

2017-06-01

Methylmercury (MeHg) is a highly toxic compound that traverses the blood-brain barrier with deleterious effects to the central nervous system. Exposure is generally through the ingestion of contaminated fish. Fish are a main source of MeHg. Goals and methods: The aim of this study was to determine the dependence of MeHg concentrations on fish species and age, the percentage of MeHg in total mercury (THg) and risk assessment depending on the size of fish. Assays of THg and MeHg were performed on the muscle tissues of 18 species of fish. The investigations indicated there were differences in the mercury concentrations depending on fish size. THg and MeHg concentrations in the muscles of fish species that have a wide length distribution were strongly, positively correlated with fish length. However, concentrations of MeHg were strongly, positively correlated with those of THg in all the fish species investigated. Variation in the percentage share of MeHg in THg in the muscles of fish of large sizes was also noted within species, but this correlation was not noted in small-sized fish. The dose of MeHg in small-sized fish species was estimated and the risk posed to consumer health was assessed using mean MeHg concentrations determined for different fish species. For species of fish that occur within a wide length distribution, the dose of MeHg should be assessed separately in different length classes. Fish consumption of small-sized species poses no health risk.

Prevalence of Clonorchis sinensis Metacercariae in Fish from Water Systems of Seomjin-gang (River).

PubMed

Sohn, Woon-Mok; Na, Byoung-Kuk; Cho, Shin-Hyeong; Park, Mi-Yeoun; Kim, Cheon-Hyeon; Hwang, Min-Ah; No, Kyeong-Woo; Yoon, Ki-Bok; Lim, Hyun-Cheol

2017-06-01

The prevalence of Clonorchis sinensis metacercariae ( Cs Mc) was examined in freshwater fish from the water systems of Seomjin-gang (River), the Republic of Korea. Total 1,604 fish from 7 local sites of Seomjin-gang were examined by artificial digestion methods. The metacercariae of C. sinensis were detected in 102 (39.8%) out of 256 fish (14 species) from the upper reaches of Seomjin-gang, i.e., Osucheon (22.3% in 6 fish species) in Imsil-gun, and Seomjin-gang (63.9% in 9 fish species) in Sunchang-gun, Jeollabuk-do. Their average density was 9.0 per infected fish. They were also found in 132 (48.0%) out of 275 fish (12 spp.) from the middle reaches of Seomjin-gang, i.e., Songdaecheon (58.9% in 4 fish species) in Namwon-si, Jeollabuk-do, and Seomjin-gang (45.2% in 10 fish species) in Gokseong-gun, Jeollanam-do. Their average density was 21.0 per infected fish. Cs Mc were detected in 77 (56.6%) out of 136 fish (11 species) from the lower reaches of Seomjin-gang, i.e., Seomjin-gang (73.3% in 11 fish species) in Gurye-gun, Jeollanam-do, and Namsancheon (8.6% in 1 fish species) in Hadong-gun, Gyeongsangnam-do. Their average density was 64.9 per infected fish. The metacercariae of Metorchis orientalis were also detected in 6 fish species from 4 sites of Seomjin-gang. Conclusively, it has been confirmed that Cs Mc are more or less prevalent in fish from some water systems of Seomjin-gang in Korea.

Prevalence of Clonorchis sinensis Metacercariae in Fish from Water Systems of Seomjin-gang (River)

PubMed Central

Sohn, Woon-Mok; Na, Byoung-Kuk; Cho, Shin-Hyeong; Park, Mi-Yeoun; Kim, Cheon-Hyeon; Hwang, Min-Ah; No, Kyeong-Woo; Yoon, Ki-Bok; Lim, Hyun-Cheol

2017-01-01

The prevalence of Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fish from the water systems of Seomjin-gang (River), the Republic of Korea. Total 1,604 fish from 7 local sites of Seomjin-gang were examined by artificial digestion methods. The metacercariae of C. sinensis were detected in 102 (39.8%) out of 256 fish (14 species) from the upper reaches of Seomjin-gang, i.e., Osucheon (22.3% in 6 fish species) in Imsil-gun, and Seomjin-gang (63.9% in 9 fish species) in Sunchang-gun, Jeollabuk-do. Their average density was 9.0 per infected fish. They were also found in 132 (48.0%) out of 275 fish (12 spp.) from the middle reaches of Seomjin-gang, i.e., Songdaecheon (58.9% in 4 fish species) in Namwon-si, Jeollabuk-do, and Seomjin-gang (45.2% in 10 fish species) in Gokseong-gun, Jeollanam-do. Their average density was 21.0 per infected fish. CsMc were detected in 77 (56.6%) out of 136 fish (11 species) from the lower reaches of Seomjin-gang, i.e., Seomjin-gang (73.3% in 11 fish species) in Gurye-gun, Jeollanam-do, and Namsancheon (8.6% in 1 fish species) in Hadong-gun, Gyeongsangnam-do. Their average density was 64.9 per infected fish. The metacercariae of Metorchis orientalis were also detected in 6 fish species from 4 sites of Seomjin-gang. Conclusively, it has been confirmed that CsMc are more or less prevalent in fish from some water systems of Seomjin-gang in Korea. PMID:28719955

Epizootiology of the ectoparasitic protozoans Ichthyobodo salmonis and Trichodina truttae on wild chum salmon Oncorhynchus keta.

PubMed

Mizuno, Shinya; Urawa, Shigehiko; Miyamoto, Mahito; Saneyoshi, Hayato; Hatakeyama, Makoto; Koide, Nobuhisa; Ueda, Hiroshi

2017-10-18

Infestations of the ectoparasitic flagellate Ichthyobodo salmonis and the ciliate Trichodina truttae have caused acute mortalities of hatchery-reared juvenile chum salmon Oncorhynchus keta in Hokkaido, northern Japan. This study examined the epizootiology of I. salmonis and T. truttae on wild chum salmon as a possible infection source of the 2 parasitic protozoans in hatcheries. Infestations by both ectoparasites were detected on freshwater-adapted adult and juvenile chum salmon in all 4 rivers examined. This is the first study of an anadromous Pacific salmonid to report infestation of I. salmonis and T. truttae in adults returning for spawning. Among the marine-inhabiting phase of chum salmon, infestation with I. salmonis, but not T. truttae, was observed on adults and juveniles. The 2 protozoans were experimentally transmitted at the same time from wild to hatchery-reared chum salmon juveniles, and caused a high rate of mortality in the hatchery fish. In freshwater, the proliferation rate of T. truttae was greater than that of I. salmonis. These observations show that the euryhaline ectoparasite I. salmonis can infest chum salmon throughout their life cycle, in both river and ocean habitats, whereas T. truttae is able to infest these salmonids only in freshwater. Furthermore, wild chum salmon were shown to be a potential infestation source for both T. truttae and I. salmonis in hatchery fish.

A two-locus molecular characterization of Paramecium calkinsi.

PubMed

Przyboś, Ewa; Tarcz, Sebastian; Potekhin, Alexey; Rautian, Maria; Prajer, Małgorzata

2012-03-01

Paramecium calkinsi (Ciliophora, Protozoa) is a euryhaline species which was first identified in freshwater habitats, but subsequently several strains were also collected from brackish water. It is characterized by clockwise spiral swimming movement and the general morphology of the "bursaria type." The present paper is the first molecular characterization of P. calkinsi strains recently collected in distant regions in Russia using ITS1-5.8S- ITS2-5'LSU rDNA (1100bp) and COI (620bp) mtDNA sequenced gene fragments. For comparison, our molecular analysis includes P. bursaria, exhibiting a similar "bursaria morphotype" as well as species representing the "aurelia type," i.e., P. caudatum, P. multimicronucleatum, P. jenningsi, and P. schewiakoffi, and some species of the P. aurelia species complex (P. primaurelia, P. tetraurelia, P. sexaurelia, and P. tredecaurelia). We also use data from GenBank concerning other species in the genus Paramecium and Tetrahymena (which used as an outgroup). The division of the genus Paramecium into four subgenera (proposed by Fokin et al. 2004) is clearly presented by the trees. There is a clear separation between P. calkinsi strains collected from different regions (races). Consequently, given the molecular distances between them, it seems that these races may represent different syngens within the species. Copyright © 2011 Elsevier GmbH. All rights reserved.

Quantifying the Human Impacts on Papua New Guinea Reef Fish Communities across Space and Time.

PubMed

Drew, Joshua A; Amatangelo, Kathryn L; Hufbauer, Ruth A

2015-01-01

Describing the drivers of species loss and of community change are important goals in both conservation and ecology. However, it is difficult to determine whether exploited species decline due to direct effects of harvesting or due to other environmental perturbations brought about by proximity to human populations. Here we quantify differences in species richness of coral reef fish communities along a human population gradient in Papua New Guinea to understand the relative impacts of fishing and environmental perturbation. Using data from published species lists we categorize the reef fishes as either fished or non-fished based on their body size and reports from the published literature. Species diversity for both fished and non-fished groups decreases as the size of the local human population increases, and this relationship is stronger in species that are fished. Additionally, comparison of modern and museum collections show that modern reef communities have proportionally fewer fished species relative to 19th century ones. Together these findings show that the reef fish communities of Papua New Guinea experience multiple anthropogenic stressors and that even at low human population levels targeted species experience population declines across both time and space.

Detection of betanodaviruses in apparently healthy aquarium fishes and invertebrates.

PubMed

Gomez, Dennis Kaw; Lim, Dong Joo; Baeck, Gun Wook; Youn, Hee Jeong; Shin, Nam Shik; Youn, Hwa Young; Hwang, Cheol Yong; Park, Jun Hong; Park, Se Chang

2006-12-01

Betanodaviruses are the causative agents of viral nervous necrosis (VNN) in cultured marine fish. A total of 237 apparently healthy aquarium fish, marine (65 species) and freshwater (12 species) fishes and marine invertebrates (4 species), which were stocked in a commercial aquarium in Seoul, South Korea, were collected from November 2005 to February 2006. The brains of the fish and other tissues of the invertebrates were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR to detect betanodavirus. Positive nested PCR results were obtained from the brains of 8 marine fish species (shrimp fish Aeoliscus strigatus, milkfish Chanos chanos, three spot damsel Dascyllus trimaculatus, Japanese anchovy Engraulis japonicus, pinecone fish Monocentris japonica, blue ribbon eel Rhinomuraena quaesita, look down fish Selene vomer, yellow tang Zebrasoma flavesenes), 1 marine invertebrate species (spiny lobster Pamulirus versicolor), and 2 freshwater fish species (South American leaf fish Monocirrhus polyacanthus and red piranha Pygocentrus nattereri). The detection rate in nested PCR was 11/237 (4.64%). These subclinically infected aquarium fish and invertebrates may constitute an inoculum source of betanodaviruses for cultured fishes in the Korean Peninsula.

Detection of betanodaviruses in apparently healthy aquarium fishes and invertebrates

PubMed Central

Gomez, Dennis Kaw; Lim, Dong Joo; Baeck, Gun Wook; Youn, Hee Jeong; Shin, Nam Shik; Youn, Hwa Young; Hwang, Cheol Yong; Park, Jun Hong

2006-01-01

Betanodaviruses are the causative agents of viral nervous necrosis (VNN) in cultured marine fish. A total of 237 apparently healthy aquarium fish, marine (65 species) and freshwater (12 species) fishes and marine invertebrates (4 species), which were stocked in a commercial aquarium in Seoul, South Korea, were collected from November 2005 to February 2006. The brains of the fish and other tissues of the invertebrates were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR to detect betanodavirus. Positive nested PCR results were obtained from the brains of 8 marine fish species (shrimp fish Aeoliscus strigatus, milkfish Chanos chanos, three spot damsel Dascyllus trimaculatus, Japanese anchovy Engraulis japonicus, pinecone fish Monocentris japonica, blue ribbon eel Rhinomuraena quaesita, look down fish Selene vomer, yellow tang Zebrasoma flavesenes), 1 marine invertebrate species (spiny lobster Pamulirus versicolor), and 2 freshwater fish species (South American leaf fish Monocirrhus polyacanthus and red piranha Pygocentrus nattereri). The detection rate in nested PCR was 11/237 (4.64%). These subclinically infected aquarium fish and invertebrates may constitute an inoculum source of betanodaviruses for cultured fishes in the Korean Peninsula. PMID:17106229

Distribution and biology of Indo-Pacific insular hypogeal shrimps

USGS Publications Warehouse

Maciolek, J.A.

1983-01-01

Ten species of caridean shrimps, representing nine genera in five families, have been found in exposures of the marine water table at 28 islands from Hawaii to the western Indian Ocean. Synthesis of literature information and personal observations indicate that, as a group, these shrimps are characterized by red body pigment, reduced but pigmented eyes, euryhalinity, a proclivity for interstitial seawater in limestone or lava rock, generalized food requirements, and probable pre-Pleistocene origins. The shrimps have not been found in waters cooler than about 20°C.Species are often solitary, but as many as five are known to coexist. Six of the species have widely scattered populations, some as far apart as Hawaii and the Red Sea. Passive oceanic dispersal is endorsed as a general explanation for such apparently disjunct distributions. On the basis of an assumed primary habitat requirement of interstitial marine water, which could include that in shallow submerged rock as well as that in emergent (insular) rock, I hypothesize a much more cosmopolitan distribution of these shrimps in the Indo-Pacific Tropical Zone.

Biochemical and physiological adaptations in the estuarine crab Neohelice granulata during salinity acclimation.

PubMed

Bianchini, Adalto; Lauer, Mariana Machado; Nery, Luiz Eduardo Maia; Colares, Elton Pinto; Monserrat, José María; Dos Santos Filho, Euclydes Antônio

2008-11-01

Neohelice granulata (Chasmagnathus granulatus) is an intertidal crab species living in salt marshes from estuaries and lagoons along the Atlantic coast of South America. It is a key species in these environments because it is responsible for energy transfer from producers to consumers. In order to deal with the extremely marked environmental salinity changes occurring in salt marshes, N. granulata shows important and interesting structural, biochemical, and physiological adaptations at the gills level. These adaptations characterize this crab as a euryhaline species, tolerating environmental salinities ranging from very diluted media to concentrated seawater. These characteristics had led to its use as an animal model to study estuarine adaptations in crustaceans. Therefore, the present review focuses on the influence of environmental salinity on N. granulata responses at the ecological, organismic and molecular levels. Aspects covered include salinity tolerance, osmo- and ionoregulatory patterns, morphological and structural adaptations at the gills, and mechanisms of ion transport and their regulation at the gills level during environmental salinity acclimation. Finally, this review compiles information on the effects of some environmental pollutants on iono- and osmoregulatory adaptations showed by N. granulata.

[Species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China].

PubMed

Zhang, Qian; Zhong, Jin-Xin

2013-05-01

Based on the related published papers, and by using Geographic Information System (ArcGIS 9.3), this paper analyzed the species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China. There were 83 threatened species living in the Province, belonging to 5 orders, 13 families, and 47 genera. Cypriniformes was absolutely dominant, with 64 species, followed by Siluriformes, with 16 species. Cyprinidae fishes had 51 species, accounting for 79.7% of Cypriniformes. The most species of Cyprinid fishes were of Barbinae (14 species), Cyprininae (10 species), and Cultrinae (10 species). The threatened fishes could be divided into two zoogeographical regions, i. e., Tibetan Plateau region and Oriental region, and their species composition and geographical distribution were resulted from the historical evolution adapted to the related environments. Whatever in rivers and in lakes, the Cyprinid fishes were both absolutely dominant, occupying 36.1% and 31.3% of the total, respectively. The Cyprinid fishes in rivers were mostly of endangered species, while those in lakes were mostly of vulnerable species. The factors affecting the threatened fishes in the Province were discussed from the two aspects of geodynamic evolution and present situation.

FishVis, A regional decision support tool for identifying vulnerabilities of riverine habitat and fishes to climate change in the Great Lakes Region

USGS Publications Warehouse

Stewart, Jana S.; Covert, S. Alex; Estes, Nick J.; Westenbroek, Stephen M.; Krueger, Damon; Wieferich, Daniel J.; Slattery, Michael T.; Lyons, John D.; McKenna, James E.; Infante, Dana M.; Bruce, Jennifer L.

2016-10-13

Climate change is expected to alter the distributions and community composition of stream fishes in the Great Lakes region in the 21st century, in part as a result of altered hydrological systems (stream temperature, streamflow, and habitat). Resource managers need information and tools to understand where fish species and stream habitats are expected to change under future conditions. Fish sample collections and environmental variables from multiple sources across the United States Great Lakes Basin were integrated and used to develop empirical models to predict fish species occurrence under present-day climate conditions. Random Forests models were used to predict the probability of occurrence of 13 lotic fish species within each stream reach in the study area. Downscaled climate data from general circulation models were integrated with the fish species occurrence models to project fish species occurrence under future climate conditions. The 13 fish species represented three ecological guilds associated with water temperature (cold, cool, and warm), and the species were distributed in streams across the Great Lakes region. Vulnerability (loss of species) and opportunity (gain of species) scores were calculated for all stream reaches by evaluating changes in fish species occurrence from present-day to future climate conditions. The 13 fish species included 4 cold-water species, 5 cool-water species, and 4 warm-water species. Presently, the 4 cold-water species occupy from 15 percent (55,000 kilometers [km]) to 35 percent (130,000 km) of the total stream length (369,215 km) across the study area; the 5 cool-water species, from 9 percent (33,000 km) to 58 percent (215,000 km); and the 4 warm-water species, from 9 percent (33,000 km) to 38 percent (141,000 km).Fish models linked to projections from 13 downscaled climate models projected that in the mid to late 21st century (2046–65 and 2081–2100, respectively) habitats suitable for all 4 cold-water species and 4 of 5 cool-water species under present-day conditions will decline as much as 86 percent and as little as 33 percent, and habitats suitable for all 4 warm-water species will increase as much as 33 percent and as little as 7 percent. This report documents the approach and data used to predict and project fish species occurrence under present-day and future climate conditions for 13 lotic fish species in the United States Great Lakes Basin. A Web-based decision support mapping application termed “FishVis” was developed to provide a means to integrate, visualize, query, and download the results of these projected climate-driven responses and help inform conservation planning efforts within the region.

Metazoan parasite species richness in Neotropical fishes: hotspots and the geography of biodiversity.

PubMed

Luque, J L; Poulin, R

2007-06-01

Although research on parasite biodiversity has intensified recently, there are signs that parasites remain an underestimated component of total biodiversity in many regions of the planet. To identify geographical hotspots of parasite diversity, we performed qualitative and quantitative analyses of the parasite-host associations in fishes from Latin America and the Caribbean, a region that includes known hotspots of plant and animal biodiversity. The database included 10,904 metazoan parasite-host associations involving 1660 fish species. The number of host species with at least 1 parasite record was less than 10% of the total known fish species in the majority of countries. Associations involving adult endoparasites in actinopterygian fish hosts dominated the database. Across the whole region, no significant difference in parasite species richness was detected between marine and freshwater fishes. As a rule, host body size and study effort (number of studies per fish species) were good predictors of parasite species richness. Some interesting patterns emerged when we included only the regions with highest fish species biodiversity and study effort (Brazil, Mexico and the Caribbean Islands). Independently of differences in study effort or host body sizes, Mexico stands out as a hotspot of parasite diversity for freshwater fishes, as does Brasil for marine fishes. However, among 57 marine fish species common to all 3 regions, populations from the Caribbean consistently harboured more parasite species. These differences may reflect true biological patterns, or regional discrepancies in study effort and local priorities for fish parasitology research.

[Dietary composition and food competition of six main fish species in rocky reef habitat off Gouqi Island].

PubMed

Wang, Kai; Zhang, Shou-Yu; Wang, Zhen-Hua; Zhao, Jing; Xu, Min; Lin, Jun

2012-02-01

Based on the monthly investigation data of fish resources in the rocky reef habitat off Gouqi Island from March 2009 to February 2010, this paper studied the dietary composition of three native fish species (Sebasticus marmoratus, Hexagrammos otakii and Hexagrammos agrammus) and three non-native fish species (Lateolabrax japonica, Nibea albiflora and Larimichthys polyactis). The analysis of gut content indicated that the main prey items of these six dominant fish species were Caprellidae, Gammaridea, juvenile S. marmoratus, Engraulis japonicas and Acetes chinensis and the dietary composition of each of the 6 fish species had obvious seasonal variation. There was an intense food competition between native species H. otakii and H. agrammus in autumn, between non-native species N. albiflora and L. polyactis in summer, between non-native species N. albiflora and native species S. marmoratus in autumn, and between non-native species N. albiflora and native species H. otakii in winter. It was suggested the non-native species N. albiflora was the key species in the food competition among the six dominant fish species in this rocky reef habitat, and thus the feeding behaviors of these six fish species could have definite effects on the resource capacity of juvenile S. marmoratus.

Otolith Length-Fish Length Relationships of Eleven US Arctic Fish Species and Their Application to Ice Seal Diet Studies

NASA Astrophysics Data System (ADS)

Walker, K. L.; Norcross, B.

2016-02-01

The Arctic ecosystem has moved into the spotlight of scientific research in recent years due to increased climate change and oil and gas exploration. Arctic fishes and Arctic marine mammals represent key parts of this ecosystem, with fish being a common part of ice seal diets in the Arctic. Determining sizes of fish consumed by ice seals is difficult because otoliths are often the only part left of the fish after digestion. Otolith length is known to be positively related to fish length. By developing species-specific otolith-body morphometric relationships for Arctic marine fishes, fish length can be determined for fish prey found in seal stomachs. Fish were collected during ice free months in the Beaufort and Chukchi seas 2009 - 2014, and the most prevalent species captured were chosen for analysis. Otoliths from eleven fish species from seven families were measured. All species had strong linear relationships between otolith length and fish total length. Nine species had coefficient of determination values over 0.75, indicating that most of the variability in the otolith to fish length relationship was explained by the linear regression. These relationships will be applied to otoliths found in stomachs of three species of ice seals (spotted Phoca largha, ringed Pusa hispida, and bearded Erignathus barbatus) and used to estimate fish total length at time of consumption. Fish lengths can in turn be used to calculate fish weight, enabling further investigation into ice seal energetic demands. This application will aid in understanding how ice seals interact with fish communities in the US Arctic and directly contribute to diet comparisons among and within ice seal species. A better understanding of predator-prey interactions in the US Arctic will aid in predicting how ice seal and fish species will adapt to a changing Arctic.

DNA barcode-based molecular identification system for fish species.

PubMed

Kim, Sungmin; Eo, Hae-Seok; Koo, Hyeyoung; Choi, Jun-Kil; Kim, Won

2010-12-01

In this study, we applied DNA barcoding to identify species using short DNA sequence analysis. We examined the utility of DNA barcoding by identifying 53 Korean freshwater fish species, 233 other freshwater fish species, and 1339 saltwater fish species. We successfully developed a web-based molecular identification system for fish (MISF) using a profile hidden Markov model. MISF facilitates efficient and reliable species identification, overcoming the limitations of conventional taxonomic approaches. MISF is freely accessible at http://bioinfosys.snu.ac.kr:8080/MISF/misf.jsp .

Cleaner fish drives local fish diversity on coral reefs.

PubMed

Grutter, Alexandra S; Murphy, Jan Maree; Choat, J Howard

2003-01-08

Coral reefs are one of the most diverse habitats in the world, yet our understanding of the processes affecting their biodiversity is limited. At the local scale, cleaner fish are thought to have a disproportionate effect, in relation to their abundance and size, on the activity of many other fish species, but confirmation of this species' effect on local fish diversity has proved elusive. The cleaner fish Labroides dimidiatus has major effects on fish activity patterns and may indirectly affect fish demography through the removal of large numbers of parasites. Here we show that small reefs where L. dimidiatus had been experimentally excluded for 18 months had half the species diversity of fish and one-fourth the abundance of individuals. Only fish that move among reefs, however, were affected. These fish include large species that themselves can affect other reef organisms. In contrast, the distribution of resident fish was not affected by cleaner fish. Thus, many fish appear to choose reefs based on the presence of cleaner fish. Our findings indicate that a single small and not very abundant fish has a strong influence on the movement patterns, habitat choice, activity, and local diversity and abundance of a wide variety of reef fish species.

Mercury and selenium levels in 19 species of saltwater fish from New Jersey as a function of species, size, and season

PubMed Central

Burger, Joanna; Gochfeld, Michael

2014-01-01

There are few data on risks to biota and humans from mercury levels in saltwater fish. This paper examines mercury and selenium levels in muscle of 19 species of fish caught by recreational fisherfolk off the New Jersey shore, as a function of species of fish, size, and season, and risk of mercury to consumers. Average mercury levels ranged from 0.01 ppm (wet weight) (Menhaden Brevoortia tyrannus) to 1.83 ppm (Mako Shark Isurus oxyrinchus). There were four categories of mercury levels: very high (only Mako), high (averaging 0.3–0.5 ppm, 3 species), medium (0.14–0.20 ppm, 10 species), and low (below 0.13 ppm, 5 species). Average selenium levels for the fish species ranged from 0.18 ppm to 0.58 ppm, and had lower variability than mercury (coefficient of variation=38.3 vs 69.1%), consistent with homeostatic regulation of this essential element. The correlation between mercury and selenium was significantly positive for five and negative for two species. Mercury levels showed significant positive correlations with fish size for ten species. Size was the best predictor of mercury levels. Selenium showed no consistent relationship to fish length. Over half of the fish species had some individual fish with mercury levels over 0.3 ppm, and a third had fish with levels over 0.5 ppm, levels that pose a human health risk for high end consumers. Conversely several fish species had no individuals above 0.5 ppm, and few above 0.3 ppm, suggesting that people who eat fish frequently, can reduce their risk from mercury by selecting which species (and which size) to consume. Overall, with the exception of shark, Bluefin Tuna (Thunnus thynnus), Bluefish (Pomatomus saltatrix) and Striped Bass (Morone saxatilis), the species sampled are generally medium to low in mercury concentration. Selenium:mercury molar ratios were generally above 1:1, except for the Mako shark. PMID:21292311

Fish assemblages in borrow-pit lakes of the Lower Mississippi River

USGS Publications Warehouse

Miranda, Leandro E.; Killgore, K. J.; Hoover, J.J.

2013-01-01

Borrow-pit lakes encompass about a third of the lentic water habitats (by area) in the active floodplain of the Lower Mississippi River, yet little is known about their fish assemblages. We investigated whether fish assemblages supported by borrow-pit lakes resembled those in oxbow lakes to help place the ecological relevance of borrow-pit lakes in context with that of natural floodplain lakes. In all, we collected 75 fish species, including 65 species in eight borrow-pit lakes, 52 species in four riverside oxbow lakes, and 44 species in eight landside oxbow lakes. Significant differences in several species richness metrics were evident between borrow-pit lakes and landside oxbow lakes but not between borrow-pit lakes and riverside oxbow lakes. All three lake types differed in fish assemblage composition. Borrow-pit lakes and riverside oxbow lakes tended to include a greater representation of fish species that require access to diverse environments, including lentic, lotic, and palustrine habitats; fish assemblages in landside oxbow lakes included a higher representation of lacustrine species. None of the fish species collected in borrow-pit lakes was federally listed as threatened or endangered, but several were listed as species of special concern by state governments in the region, suggesting that borrow-pit lakes provide habitat for sensitive riverine and wetland fish species. Differences in fish assemblages among borrow-pit lakes were linked to engineered morphologic features, suggesting that diversity in engineering can contribute to diversity in fish assemblages; however, more research is needed to match engineering designs with fish assemblage structures that best meet conservation needs.

Fish-allergic patients may be able to eat fish.

PubMed

Mourad, Ahmad A; Bahna, Sami L

2015-03-01

Reported fish allergy prevalence varies widely, with an estimated prevalence of 0.2% in the general population. Sensitization to fish can occur by ingestion, skin contact or inhalation. The manifestations can be IgE or non-IgE mediated. Several fish allergens have been identified, with parvalbumins being the major allergen in various species. Allergenicity varies among fish species and is affected by processing or preparation methods. Adverse reactions after eating fish are often claimed to be 'allergy' but could be a reaction to hidden food allergen, fish parasite, fish toxins or histamine in spoiled fish. Identifying such causes would allow free consumption of fish. Correct diagnosis of fish allergy, including the specific species, might provide the patient with safe alternatives. Patients have been generally advised for strict universal avoidance of fish. However, testing with various fish species or preparations might identify one or more forms that can be tolerated.

Identification of the putative goldfish (Carassius auratus) magnesium transporter SLC41a1 and functional regulation in the gill, kidney, and intestine in response to dietary and environmental manipulations.

PubMed

Kodzhahinchev, Vladimir; Kovacevic, Drago; Bucking, Carol

2017-04-01

While magnesium requirements for teleost fish highlight the physiological importance of this cation for homeostasis, little is known regarding the molecular identity of transporters responsible for magnesium absorption or secretion. The recent characterization of the vertebrate magnesium transporter solute carrier 41a1 (SLC41a1) in the kidney of a euryhaline fish has provided a glimpse of possible moieties involved in piscine magnesium regulation. The present study obtained a novel SLC41a1 coding sequence for Carassius auratus and demonstrated ubiquitous expression in all tissues examined. Transcriptional regulation of SLC41a1 in response to dietary and environmental magnesium concentrations was observed across tissues. Specifically, decreased environmental magnesium correlated with decreased expression of SLC41a1 in the intestine, whereas the gill and kidney were unaffected. Dietary magnesium restriction correlated with decreased expression of SLC41a1 in the intestine and gill, while again no effects were detected in the kidney. Finally, elevated dietary magnesium correlated with increased expression of SLC41a1 in the kidney, while expression in the intestine and gill remained stable. Plasma magnesium was maintained in all treatments, and dietary assimilation efficiency increased with decreased dietary magnesium. Consumption of a single meal failed to impact SLC41a1 expression, and transcript abundance remained stable over the course of digestion in all treatments. Transcriptional regulation occurred between 7 and 14days following dietary and environmental manipulations and short-term regulation (e.g. <24h) was not observed. Overall the data supports transcriptional regulation of SLC41a1 reflecting a possible role in magnesium loss or secretion across tissues in fish. Copyright © 2017 Elsevier Inc. All rights reserved.

Early Response of Protein Quality Control in Gills Is Associated with Survival of Hypertonic Shock in Mozambique tilapia

PubMed Central

Tang, Cheng-Hao; Lee, Tsung-Han

2013-01-01

The protein quality control (PQC) mechanism is essential for cell function and viability. PQC with proper biological function depends on molecular chaperones and proteases. The hypertonicity-induced protein damage and responses of PQC mechanism in aquatic organisms, however, are poorly understood. In this study, we examine the short-term effects of different hypertonic shocks on the levels of heat shock proteins (HSPs, e.g., HSP70 and HSP90), ubiquitin-conjugated proteins and protein aggregation in gills of the Mozambique tilapia (Oreochromis mossambicus). Following transfer from fresh water (FW) to 20‰ hypertonicity, all examined individuals survived to the end of experiment. Moreover, the levels of branchial HSPs and ubiquitin-conjugated proteins significantly increased at 3 and 24 h post-transfer, respectively. Up-regulation of HSPs and ubiquitin-conjugated proteins was sufficient to prevent the accumulation of aggregated proteins. However, the survival rate of tilapia dramatically declined at 5 h and all fish died within 7 h after direct transfer to 30‰ hypertonicity. We presumed that this result was due to the failed activation of gill PQC system, which resulted in elevating the levels of aggregated proteins at 3 and 4 h. Furthermore, in aggregated protein fractions, the amounts of gill Na+/K+-ATPase (NKA) remained relatively low when fish were transferred to 20‰ hypertonicity, whereas abundant NKA was found at 4 h post-transfer to 30‰ hypertonicity. This study demonstrated that the response of PQC in gills is earlier than observable changes in localization of ion-secreting transport proteins upon hypertonic challenge. To our knowledge, this is the first study to investigate the regulation of PQC mechanism in fish and characterize its important role in euryhaline teleost survival in response to hypertonic stress. PMID:23690986

Biochemical characteristics and modulation by external and internal factors of aminopeptidase-N activity in the hepatopancreas of a euryhaline burrowing crab.

PubMed

Michiels, M S; del Valle, J C; López Mañanes, A A

2015-07-01

Strikingly, in spite of its physiological importance, information about occurrence, biochemical characteristics and mechanisms of regulation of aminopeptidase-N (APN) in the hepatopancreas of intertidal euryhaline crabs is still lacking. In this work, we determined the occurrence, biochemical characteristics, response to environmental salinity and dopamine of APN in the hepatopancreas of the euryhaline crab Neohelice granulata (Dana 1851) from the open mudflat of Mar Chiquita coastal lagoon (Buenos Aires province, Argentina). APN activity was maximal at pH and temperature range of 7.6-9.0 and 37-45 °C, respectively. APN activity exhibited Michaelis-Menten kinetics (apparent Km = 0.19 ± 0.10 mM) (pH 7.6, 37 °C) and appeared to be sensitive to bestatin (I 50 = 15 mM) and EDTA (I 50 = 9 mM). In crabs acclimated to 10 psu (hyper-regulation conditions) and 37 psu (hypo-regulation conditions), APN activity was about 45 and 160% higher, respectively, than in 35 psu (osmoconformation). APN activity in the hepatopancreas was stimulated in vitro (about 137%) by 10(-4) M dopamine. Higher dopamine concentrations produced a similar extent of increase. The responses of APN activity to salinity and dopamine in vitro suggest the role of APN in digestive adjustments upon hyper and hypo-regulatory conditions and its modulation via direct mechanisms on hepatopancreas by dopamine.

The putative mechanism of Na(+) absorption in euryhaline elasmobranchs exists in the gills of a stenohaline marine elasmobranch, Squalus acanthias.

PubMed

Choe, Keith P; Edwards, Susan L; Claiborne, James B; Evans, David H

2007-02-01

We recently cloned an NHE3 orthologue from the gills of the euryhaline Atlantic stingray (Dasyatis sabina), and generated a stingray NHE3 antibody to unequivocally localize the exchanger to the apical side of epithelial cells that are rich with Na(+)/K(+)-ATPase (A MRC). We also demonstrated an increase in NHE3 expression when stingrays are in fresh water, suggesting that NHE3 is responsible for active Na(+) absorption. However, the vast majority of elasmobranchs are only found in marine environments. In the current study, immunohistochemistry with the stingray NHE3 antibody was used to localize the exchanger in the gills of the stenohaline marine spiny dogfish shark (Squalus acanthias). NHE3 immunoreactivity was confined to the apical side of cells with basolateral Na(+)/K(+)-ATPase and was excluded from cells with high levels of vacuolar H(+)-ATPase. Western blots detected a single protein of 88 kDa in dogfish gills, the same size as NHE3 in stingrays and mammals. These immunological data demonstrate that the putative cell type responsible for active Na(+) absorption in euryhaline elasmobranchs is also present in stenohaline marine elasmobranchs, and suggest that the inability of most elasmobranchs to survive in fresh water is not due to a lack of the gill ion transporters for Na(+) absorption.

75 FR 2106 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-14

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... NMFS regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in... steelhead not to exceed 2 percent of the total number of fish captured for each life stage and species...

Metazoan Parasites of Antarctic Fishes.

PubMed

Oğuz, Mehmet Cemal; Tepe, Yahya; Belk, Mark C; Heckmann, Richard A; Aslan, Burçak; Gürgen, Meryem; Bray, Rodney A; Akgül, Ülker

2015-06-01

To date, there have been nearly 100 papers published on metazoan parasites of Antarctic fishes, but there has not yet been any compilation of a species list of fish parasites for this large geographic area. Herein, we provide a list of all documented occurrences of monogenean, cestode, digenean, acanthocephalan, nematode, and hirudinean parasites of Antarctic fishes. The list includes nearly 250 parasite species found in 142 species of host fishes. It is likely that there are more species of fish parasites, which are yet to be documented from Antarctic waters.

9 CFR 83.3 - Interstate movement of live VHS-regulated fish species from VHS-regulated areas.

Code of Federal Regulations, 2012 CFR

2012-01-01

...-regulated fish species from VHS-regulated areas. 83.3 Section 83.3 Animals and Animal Products ANIMAL AND...-regulated fish species from VHS-regulated areas. (a) Except as provided in paragraphs (b) through (e) of this section, live VHS-regulated fish, including fish moved to live fish markets, may only be moved...

9 CFR 83.3 - Interstate movement of live VHS-regulated fish species from VHS-regulated areas.

Code of Federal Regulations, 2011 CFR

2011-01-01

...-regulated fish species from VHS-regulated areas. 83.3 Section 83.3 Animals and Animal Products ANIMAL AND...-regulated fish species from VHS-regulated areas. (a) Except as provided in paragraphs (b) through (e) of this section, live VHS-regulated fish, including fish moved to live fish markets, may only be moved...

9 CFR 83.3 - Interstate movement of live VHS-regulated fish species from VHS-regulated areas.

Code of Federal Regulations, 2013 CFR

2013-01-01

...-regulated fish species from VHS-regulated areas. 83.3 Section 83.3 Animals and Animal Products ANIMAL AND...-regulated fish species from VHS-regulated areas. (a) Except as provided in paragraphs (b) through (e) of this section, live VHS-regulated fish, including fish moved to live fish markets, may only be moved...

9 CFR 83.3 - Interstate movement of live VHS-regulated fish species from VHS-regulated areas.

Code of Federal Regulations, 2014 CFR

2014-01-01

...-regulated fish species from VHS-regulated areas. 83.3 Section 83.3 Animals and Animal Products ANIMAL AND...-regulated fish species from VHS-regulated areas. (a) Except as provided in paragraphs (b) through (e) of this section, live VHS-regulated fish, including fish moved to live fish markets, may only be moved...

9 CFR 83.3 - Interstate movement of live VHS-regulated fish species from VHS-regulated areas.

Code of Federal Regulations, 2010 CFR

2010-01-01

...-regulated fish species from VHS-regulated areas. 83.3 Section 83.3 Animals and Animal Products ANIMAL AND...-regulated fish species from VHS-regulated areas. (a) Except as provided in paragraphs (b) through (e) of this section, live VHS-regulated fish, including fish moved to live fish markets, may only be moved...

Total mercury levels in commercial fish species from Italian fishery and aquaculture.

PubMed

Di Lena, Gabriella; Casini, Irene; Caproni, Roberto; Fusari, Andrea; Orban, Elena

2017-06-01

Total mercury levels were measured in 42 commercial fish species caught off the Central Adriatic and Tyrrhenian coasts of Italy and in 6 aquaculture species. The study on wild fish covered species differing in living habitat and trophic level. The study on farmed fish covered marine and freshwater species from intensive and extensive aquaculture and their feed. Mercury levels were analysed by thermal decomposition-amalgamation-atomic absorption spectrophotometry. Total mercury concentrations in the muscle of wild fish showed a high variability among species (0.025-2.20 mg kg -1 wet weight). The lowest levels were detected in low trophic-level demersal and pelagic-neritic fish and in young individuals of high trophic-level species. Levels exceeding the European Commission limits were found in large-size specimens of high trophic-level pelagic and demersal species. Fish from intensive farming showed low levels of total mercury (0.008-0.251 mg kg -1 ). Fish from extensive rearing showed variable contamination levels, depending on the area of provenience. An estimation of the human intake of mercury associated to the consumption of the studied fish and its comparison with the tolerable weekly intake is provided.

Effects of Fishing and Regional Species Pool on the Functional Diversity of Fish Communities

PubMed Central

Martins, Gustavo M.; Arenas, Francisco; Neto, Ana I.; Jenkins, Stuart R.

2012-01-01

The potential population and community level impacts of fishing have received considerable attention, but little is known about how fishing influences communities’ functional diversity at regional scales. We examined how estimates of functional diversity differed among 25 regions of variable richness and investigated the functional consequences of removing species targeted by commercial fisheries. Our study shows that fishing leads to substantial losses in functional diversity. The magnitude of such loss was, however, reduced in the more speciose regions. Moreover, the removal of commercially targeted species caused a much larger reduction in functional diversity than expected by random species deletions, which was a consequence of the selective nature of fishing for particular species traits. Results suggest that functional redundancy is spatially variable, that richer biotas provide some degree of insurance against the impact of fishing on communities’ functional diversity and that fishing predominantly selects for particular species traits. Understanding how fishing impacts community functional diversity is key to predict its effects for biodiversity as well as ecosystem functioning. PMID:22952950

Effects of fishing and regional species pool on the functional diversity of fish communities.

PubMed

Martins, Gustavo M; Arenas, Francisco; Neto, Ana I; Jenkins, Stuart R

2012-01-01

The potential population and community level impacts of fishing have received considerable attention, but little is known about how fishing influences communities' functional diversity at regional scales. We examined how estimates of functional diversity differed among 25 regions of variable richness and investigated the functional consequences of removing species targeted by commercial fisheries. Our study shows that fishing leads to substantial losses in functional diversity. The magnitude of such loss was, however, reduced in the more speciose regions. Moreover, the removal of commercially targeted species caused a much larger reduction in functional diversity than expected by random species deletions, which was a consequence of the selective nature of fishing for particular species traits. Results suggest that functional redundancy is spatially variable, that richer biotas provide some degree of insurance against the impact of fishing on communities' functional diversity and that fishing predominantly selects for particular species traits. Understanding how fishing impacts community functional diversity is key to predict its effects for biodiversity as well as ecosystem functioning.

Chemical composition, mineral content and amino acid and lipid profiles in bones from various fish species.

PubMed

Toppe, Jogeir; Albrektsen, Sissel; Hope, Britt; Aksnes, Anders

2007-03-01

The chemical composition, content of minerals and the profiles of amino acids and fatty acids were analyzed in fish bones from eight different species of fish. Fish bones varied significantly in chemical composition. The main difference was lipid content ranging from 23 g/kg in cod (Gadus morhua) to 509 g/kg in mackerel (Scomber scombrus). In general fatty fish species showed higher lipid levels in the bones compared to lean fish species. Similarly, lower levels of protein and ash were observed in bones from fatty fish species. Protein levels differed from 363 g/kg lipid free dry matter (dm) to 568 g/kg lipid free dm with a concomitant inverse difference in ash content. Ash to protein ratio differed from 0.78 to 1.71 with the lowest level in fish that naturally have highest swimming and physical activity. Saithe (Pollachius virens) and salmon (Salmo salar) were found to be significantly different in the levels of lipid, protein and ash, and ash/protein ratio in the bones. Only small differences were observed in the level of amino acids although species specific differences were observed. The levels of Ca and P in lipid free fish bones were about the same in all species analyzed. Fatty acid profile differed in relation to total lipid levels in the fish bones, but some minor differences between fish species were observed.

Identification and lateral membrane localization of cyclin M3, likely to be involved in renal Mg2+ handling in seawater fish

PubMed Central

Islam, Zinia; Hayashi, Naoko; Inoue, Hana; Umezawa, Takahiro; Kimura, Yuuri; Doi, Hiroyuki; Romero, Michael F.; Hirose, Shigehisa

2014-01-01

The kidney of marine teleosts is the major site of Mg2+ excretion and produces urine with a high Mg2+ concentration. However, the transporters involved in Mg2+ excretion are poorly understood. The cyclin M (Cnnm; also known as ancient conserved domain protein) family comprises membrane proteins homologous to the bacterial Mg2+ and Co2+ efflux protein, CorC. To understand the molecular mechanism of Mg2+ homeostasis in marine teleosts, we analyzed the expression of the Cnnm family genes in the seawater (SW) pufferfish, torafugu (Takifugu rubripes), and the closely related euryhaline species, mefugu (Takifugu obscurus). Database mining and phylogenetic analysis indicated that the Takifugu genome contains six members of the Cnnm family: two orthologs of Cnnm1, one of Cnnm2, one of Cnnm3, and two of Cnnm4. RT-PCR analyses indicated that Cnnm2, Cnnm3, and Cnnm4a are expressed in the kidney, whereas other members are mainly expressed in the brain. Renal expression of Cnnm3 was upregulated in SW mefugu, whereas renal expression of Cnnm2 was upregulated in freshwater (FW) mefugu. No significant difference was observed in renal expression of Cnnm4a between SW and FW mefugu. In situ hybridization and immunohistochemical analyses of the SW mefugu kidney revealed that Cnnm3 is expressed in the proximal tubule, and its product localizes to the lateral membrane. When Cnnm3 was expressed in Xenopus laevis oocytes, whole cellular Mg2+ content and free intracellular Mg2+ activity significantly decreased. These results suggest that Cnnm3 is involved in body fluid Mg2+ homeostasis in marine teleosts. PMID:24965791

Transcriptomic analysis of adaptive mechanisms in response to sudden salinity drop in the mud crab, Scylla paramamosain.

PubMed

Wang, Huan; Tang, Lei; Wei, Hongling; Lu, Junkai; Mu, Changkao; Wang, Chunlin

2018-05-31

Scylla paramamosain (Crustacea: Decapoda: Portunidae: Syclla De Hann) is a commercially important mud crab distributed along the coast of southern China and other Indo-Pacific countries (Lin Z, Hao M, Zhu D, et al, Comp Biochem Physiol B Biochem Mol Biol 208-209:29-37, 2017; Walton ME, Vay LL, Lebata JH, et al, Estuar Coast Shelf Sci 66(3-4):493-500, 2006; Wang Z, Sun B, Zhu F, Fish Shellfish Immunol 67:612-9, 2017). While S. paramamosain is a euryhaline species, a sudden drop in salinity induces a negative impact on growth, molting, and reproduction, and may even cause death. The mechanism of osmotic regulation of marine crustaceans has been recently under investigation. However, the mechanism of adapting to a sudden drop in salinity has not been reported. In this study, transcriptomics analysis was conducted on the gills of S. paramamosain to test its adaptive capabilities over 120 h with a sudden drop in salinity from 23 ‰ to 3 ‰. At the level of transcription, 135 DEGs (108 up-regulated and 27 down-regulated) annotated by NCBI non-redundant (nr) protein database were screened. GO analysis showed that the catalytic activity category showed the most participating genes in the 24 s-tier GO terms, indicating that intracellular metabolic activities in S. paramamosain were enhanced. Of the 164 mapped KEGG pathways, seven of the top 20 pathways were closely related to regulation of the Na + / K + -ATPase. Seven additional amino acid metabolism-related pathways were also found, along with other important signaling pathways. Ion transport and amino acid metabolism were key factors in regulating the salinity adaptation of S. paramamosain in addition to several important signaling pathways.

9 CFR 93.911 - Ports designated for the importation of live VHS-regulated fish species.

Code of Federal Regulations, 2012 CFR

2012-01-01

... of live VHS-regulated fish species. 93.911 Section 93.911 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN... Animal Species General Provisions for Vhs-Regulated Fish Species § 93.911 Ports designated for the...

9 CFR 93.911 - Ports designated for the importation of live VHS-regulated fish species.

Code of Federal Regulations, 2014 CFR

2014-01-01

... of live VHS-regulated fish species. 93.911 Section 93.911 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN... Animal Species General Provisions for Vhs-Regulated Fish Species § 93.911 Ports designated for the...

9 CFR 93.911 - Ports designated for the importation of live VHS-regulated fish species.

Code of Federal Regulations, 2013 CFR

2013-01-01

... of live VHS-regulated fish species. 93.911 Section 93.911 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN... Animal Species General Provisions for Vhs-Regulated Fish Species § 93.911 Ports designated for the...

9 CFR 93.911 - Ports designated for the importation of live VHS-regulated fish species.

Code of Federal Regulations, 2010 CFR

2010-01-01

... of live VHS-regulated fish species. 93.911 Section 93.911 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN... Animal Species General Provisions for Vhs-Regulated Fish Species § 93.911 Ports designated for the...

Checklists of Parasites of Farm Fishes of Babylon Province, Iraq

PubMed Central

Al-Rubaie, Abdul-Razzak L.

2016-01-01

Literature reviews of all references concerning the parasitic fauna of fishes in fish farms of Babylon province, middle of Iraq, showed that a total of 92 valid parasite species are so far known from the common carp (Cyprinus carpio), the grass carp (Ctenopharyngodon idella), and the silver carp (Hypophthalmichthys molitrix) as well as from three freshwater fish species (Carassius auratus, Liza abu, and Heteropneustes fossilis) which were found in some fish farms of the same province. The parasitic fauna included one mastigophoran, three apicomplexans, 13 ciliophorans, five myxozoans, five trematodes, 45 monogeneans, five cestodes, three nematodes, two acanthocephalans, nine arthropods, and one mollusc. The common carp was found to harbour 81 species of parasites, the grass carp 30 species, the silver carp 28 species, L. abu 13 species, C. auratus one species, and H. fossilis one species. A host-parasite list for each fish species was also provided. PMID:27559480

Distribution and habitat association of benthic fish on the Condor seamount (NE Atlantic, Azores) from in situ observations

NASA Astrophysics Data System (ADS)

Porteiro, Filipe M.; Gomes-Pereira, José N.; Pham, Christopher K.; Tempera, Fernando; Santos, Ricardo S.

2013-12-01

Distribution of fish assemblages and habitat associations of demersal fishes on the Condor seamount were investigated by analyzing in situ video imagery acquired by the Remotely-Operated Vehicles ROV SP300 and Luso 6000. A total of 51 fish taxa from 32 families were inventoried. Zooplanktivores (10 species) were the most abundant group followed by carnivores (23 species) and benthivores (18 species). Non-metric multidimensional scaling (MDS) analyses were performed on dive segments to visualize the spatial relationships between species and habitat type, substrate type or depth, with depth being the most significant parameter influencing fish distribution. Four major fish groups were identified from their vertical distribution alone: summit species (generally to <300 m depth); broad ranging species (ca. from 200 to 800 m); intermediate ranging slope species (ca. from 400 m to 800-850 m); and deeper species (800-850-1100 m). The fish fauna observed at the summit is more abundant (15.2 fish/100 m2) and habitat-specialized than the fish observed along the seamount slope. Down the seamount slope, the summit fish assemblage is gradually replaced as depth increases, with an overall reduction in abundance. On the summit, three species (Callanthias ruber, Anthias anthias and Lappanella fasciata) had higher affinity to coral habitats compared to non-coral habitats. A coherent specialized fish assemblage associated to coral habitats could not be identified, because most species were observed also in non-coral areas. On the seamount's slope (300-1100 m), no relationship between fish and coral habitats could be identified, although these might occur at larger scales. This study shows that in situ video imagery complements traditional fishing surveys, by providing information on unknown or rarely seen species, being fundamental for the development of more comprehensive ecosystem-based management towards a sustainable use of the marine environment.

Characterization of Ras k 1 a novel major allergen in Indian mackerel and identification of parvalbumin as the major fish allergen in 33 Asia-Pacific fish species.

PubMed

Ruethers, T; Raith, M; Sharp, M F; Koeberl, M; Stephen, J N; Nugraha, R; Le, T T K; Quirce, S; Nguyen, H X M; Kamath, S D; Mehr, S S; Campbell, D E; Bridges, C R; Taki, A C; Swoboda, I; Lopata, A L

2018-04-01

Fish is a well-recognized cause of food allergy and anaphylaxis. The evolutionary and taxonomic diversity of the various consumed fish species pose a challenge in the identification and characterization of the major fish allergens critical for reliable diagnostics. Globally, fish is a rising cause of food allergy complicated by a large under-investigated variety of species as well as increasing global tourism and trade. This is the first comprehensive study on allergen profiles of heat-processed fish from Vietnam. The aim of this study was to identify the major heat-stable allergens from frequently exported Asia-Pacific freshwater and marine fish and to characterize the major allergen parvalbumin (PV) from one of the most consumed and exported fish species from Asia, the Indian mackerel (Rastrelliger kanagurta). Heated protein extracts from 33 fish species were separated by gel electrophoresis. PV isoforms were identified by immunoblotting utilizing 3 different PV-specific monoclonal and polyclonal antibodies and further characterized by mass spectrometry. IgE reactivity was investigated using sera from 21 patients with confirmed fish allergy. Heat-stable IgE-reactive PVs, with up to 5 isoforms per species, were identified in all 33 analysed fish species. In the Indian mackerel, 7 PV isoforms were identified by 2D-gel electrophoresis combined with mass spectrometric analyses. The amino acid sequence deduced from cDNA of the most expressed isoform showed a high identity (>90%) to PVs from 2 other mackerel species. Different PVs were identified as the major heat-stable allergens in all 33 analysed freshwater and marine fish species from Vietnam, many of which are exported world-wide and 21 species that have never been investigated before. The Indian mackerel PV represents a novel fish allergen, now officially registered as Ras k 1. Improved diagnostics for fish allergy against Asia-Pacific species should be developed with focus on PV. © 2017 John Wiley & Sons Ltd.

50 CFR Table 2c to Part 679 - Species Codes: FMP Forage Fish Species (all species of the following families)

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Species Codes: FMP Forage Fish Species (all species of the following families) 2c Table 2c to Part 679 Wildlife and Fisheries FISHERY...: FMP Forage Fish Species (all species of the following families) Species Description Code Bristlemouths...

50 CFR Table 2c to Part 679 - Species Codes: FMP Forage Fish Species (all species of the following families)

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Species Codes: FMP Forage Fish Species (all species of the following families) 2c Table 2c to Part 679 Wildlife and Fisheries FISHERY...: FMP Forage Fish Species (all species of the following families) Species Description Code Bristlemouths...

50 CFR Table 2c to Part 679 - Species Codes: FMP Forage Fish Species (all species of the following families)

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Species Codes: FMP Forage Fish Species (all species of the following families) 2c Table 2c to Part 679 Wildlife and Fisheries FISHERY...: FMP Forage Fish Species (all species of the following families) Species Description Code Bristlemouths...

50 CFR Table 2c to Part 679 - Species Codes: FMP Forage Fish Species (all species of the following families)

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Species Codes: FMP Forage Fish Species (all species of the following families) 2c Table 2c to Part 679 Wildlife and Fisheries FISHERY...: FMP Forage Fish Species (all species of the following families) Species Description Code Bristlemouths...

50 CFR Table 2c to Part 679 - Species Codes: FMP Forage Fish Species (all species of the following families)

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Species Codes: FMP Forage Fish Species (all species of the following families) 2c Table 2c to Part 679 Wildlife and Fisheries FISHERY...: FMP Forage Fish Species (all species of the following families) Species Description Code Bristlemouths...

Metabolic organization of freshwater, euryhaline, and marine elasmobranchs: implications for the evolution of energy metabolism in sharks and rays.

PubMed

Speers-Roesch, B; Ip, Y K; Ballantyne, J S

2006-07-01

To test the hypothesis that the preference for ketone bodies rather than lipids as oxidative fuel in elasmobranchs evolved in response to the appearance of urea-based osmoregulation, we measured total non-esterified fatty acids (NEFA) in plasma as well as maximal activities of enzymes of intermediary metabolism in tissues from marine and freshwater elasmobranchs, including: the river stingray Potamotrygon motoro (<1 mmol l(-1) plasma urea); the marine stingray Taeniura lymma, and the marine shark Chiloscyllium punctatum (>300 mmol l(-1) plasma urea); and the euryhaline freshwater stingray Himantura signifer, which possesses intermediate levels of urea. H. signifer also were acclimated to half-strength seawater (15 per thousand) for 2 weeks to ascertain the metabolic effects of the higher urea level that results from salinity acclimation. Our results do not support the urea hypothesis. Enzyme activities and plasma NEFA in salinity-challenged H. signifer were largely unchanged from the freshwater controls, and the freshwater elasmobranchs did not show an enhanced capacity for extrahepatic lipid oxidation relative to the marine species. Importantly, and contrary to previous studies, extrahepatic lipid oxidation does occur in elasmobranchs, based on high carnitine palmitoyl transferase (CPT) activities in kidney and rectal gland. Heart CPT in the stingrays was detectable but low, indicating some capacity for lipid oxidation. CPT was undetectable in red muscle, and almost undetectable in heart, from C. punctatum as well as in white muscle from T. lymma. We propose a revised model of tissue-specific lipid oxidation in elasmobranchs, with high levels in liver, kidney and rectal gland, low or undetectable levels in heart, and none in red or white muscle. Plasma NEFA levels were low in all species, as previously noted in elasmobranchs. D-beta-hydroxybutyrate dehydrogenase (d-beta-HBDH) was high in most tissues confirming the importance of ketone bodies in elasmobranchs. However, very low d-beta-HBDH in kidney from T. lymma indicates that interspecific variability in ketone body utilization occurs. A negative relationship was observed across species between liver glutamate dehydrogenase activity and tissue or plasma urea levels, suggesting that glutamate is preferentially deaminated in freshwater elasmobranchs because it does not need to be shunted to urea production as in marine elasmobranchs.

Spatial fishing restrictions benefit demersal stocks in the northeastern Mediterranean Sea.

PubMed

Dimarchopoulou, Donna; Dogrammatzi, Aikaterini; Karachle, Paraskevi K; Tsikliras, Athanassios C

2018-04-13

The multi-level benefits that marine organisms gain when protected from fishing are well acknowledged. Here, we investigated the effects of a 40-year trawling ban on the status of targeted and non-targeted marine species within a major fishing ground in the northeastern Mediterranean Sea (Thermaikos Gulf, Aegean Sea). Biomass and somatic length of fish and invertebrates (six commercial and three non-commercial demersal species) were measured in three areas of varying fishing pressure, depending on the temporal and spatial operational regimes of fishing vessels. The positive effects of fishing restrictions on the studied demersal stocks were clearly revealed, as the commercial fish species exhibited higher biomass in the intermediate and low pressure areas, as well as increasing maximum and mean total length (and other length indicators) with decreasing fishing effort. The mean total length of non-commercial species generally did not differ among areas, except for species caught and discarded at high rates. The present study shows that fishing does alter the population structure and biomass of commercial demersal species, and that fishing restrictions greatly contribute to improving the status of demersal populations within the restricted areas by providing a refuge for large individuals and their important contribution to the gene pool.

Impact of High Seas Closure on Food Security in Low Income Fish Dependent Countries

PubMed Central

Teh, Louise S. L.; Lam, Vicky W. Y.; Cheung, William W. L.; Miller, Dana; Teh, Lydia C. L.; Sumaila, U. Rashid

2016-01-01

We investigate how high seas closure will affect the availability of commonly consumed food fish in 46 fish reliant, and/or low income countries. Domestic consumption of straddling fish species (fish that would be affected by high seas closure) occurred in 54% of the assessed countries. The majority (70%) of countries were projected to experience net catch gains following high seas closure. However, countries with projected catch gains and that also consumed the straddling fish species domestically made up only 37% of the assessed countries. In contrast, much fewer countries (25%) were projected to incur net losses from high seas closure, and of these, straddling species were used domestically in less than half (45%) of the countries. Our findings suggest that, given the current consumption patterns of straddling species, high seas closure may only directly benefit the supply of domestically consumed food fish in a small number of fish reliant and/or low income countries. In particular, it may not have a substantial impact on improving domestic fish supply in countries with the greatest need for improved access to affordable fish, as only one third of this group used straddling fish species domestically. Also, food security in countries with projected net catch gains but where straddling fish species are not consumed domestically may still benefit indirectly via economic activities arising from the increased availability of non-domestically consumed straddling fish species following high seas closure. Consequently, this study suggests that high seas closure can potentially improve marine resource sustainability as well as contribute to human well-being in some of the poorest and most fish dependent countries worldwide. However, caution is required because high seas closure may also negatively affect fish availability in countries that are already impoverished and fish insecure. PMID:28033359

Impact of High Seas Closure on Food Security in Low Income Fish Dependent Countries.

PubMed

Teh, Louise S L; Lam, Vicky W Y; Cheung, William W L; Miller, Dana; Teh, Lydia C L; Sumaila, U Rashid

2016-01-01

We investigate how high seas closure will affect the availability of commonly consumed food fish in 46 fish reliant, and/or low income countries. Domestic consumption of straddling fish species (fish that would be affected by high seas closure) occurred in 54% of the assessed countries. The majority (70%) of countries were projected to experience net catch gains following high seas closure. However, countries with projected catch gains and that also consumed the straddling fish species domestically made up only 37% of the assessed countries. In contrast, much fewer countries (25%) were projected to incur net losses from high seas closure, and of these, straddling species were used domestically in less than half (45%) of the countries. Our findings suggest that, given the current consumption patterns of straddling species, high seas closure may only directly benefit the supply of domestically consumed food fish in a small number of fish reliant and/or low income countries. In particular, it may not have a substantial impact on improving domestic fish supply in countries with the greatest need for improved access to affordable fish, as only one third of this group used straddling fish species domestically. Also, food security in countries with projected net catch gains but where straddling fish species are not consumed domestically may still benefit indirectly via economic activities arising from the increased availability of non-domestically consumed straddling fish species following high seas closure. Consequently, this study suggests that high seas closure can potentially improve marine resource sustainability as well as contribute to human well-being in some of the poorest and most fish dependent countries worldwide. However, caution is required because high seas closure may also negatively affect fish availability in countries that are already impoverished and fish insecure.

Mercury and selenium levels in 19 species of saltwater fish from New Jersey as a function of species, size, and season.

PubMed

Burger, Joanna; Gochfeld, Michael

2011-03-15

There are few data on risks to biota and humans from mercury levels in saltwater fish. This paper examines mercury and selenium levels in muscle of 19 species of fish caught by recreational fisherfolk off the New Jersey shore, as a function of species of fish, size, and season, and risk of mercury to consumers. Average mercury levels ranged from 0.01 ppm (wet weight) (Menhaden Brevoortia tyrannus) to 1.83 ppm (Mako Shark Isurus oxyrinchus). There were four categories of mercury levels: very high (only Mako), high (averaging 0.3-0.5 ppm, 3 species), medium (0.14-0.20 ppm, 10 species), and low (below 0.13 ppm, 5 species). Average selenium levels for the fish species ranged from 0.18 ppm to 0.58 ppm, and had lower variability than mercury (coefficient of variation=38.3 vs 69.1%), consistent with homeostatic regulation of this essential element. The correlation between mercury and selenium was significantly positive for five and negative for two species. Mercury levels showed significant positive correlations with fish size for ten species. Size was the best predictor of mercury levels. Selenium showed no consistent relationship to fish length. Over half of the fish species had some individual fish with mercury levels over 0.3 ppm, and a third had fish with levels over 0.5 ppm, levels that pose a human health risk for high end consumers. Conversely several fish species had no individuals above 0.5 ppm, and few above 0.3 ppm, suggesting that people who eat fish frequently, can reduce their risk from mercury by selecting which species (and which size) to consume. Overall, with the exception of shark, Bluefin Tuna (Thunnus thynnus), Bluefish (Pomatomus saltatrix) and Striped Bass (Morone saxatilis), the species sampled are generally medium to low in mercury concentration. Selenium:mercury molar ratios were generally above 1:1, except for the Mako shark. Copyright © 2010 Elsevier B.V. All rights reserved.

Fish assemblage responses to urban intensity gradients in contrasting metropolitan areas: Birmingham, Alabama and Boston, Massachusetts

USGS Publications Warehouse

Meador, M.R.; Coles, J.F.; Zappia, H.

2005-01-01

We examined fish assemblage responses to urban intensify gradients in two contrasting metropolitan areas: Birmingham, Alabama (BIR) and Boston, Massachusetts (BOS). Urbanization was quantified by using an urban intensity index (UII) that included multiple stream buffers and basin land uses, human population density, and road density variables. We evaluated fish assemblage responses by using species richness metrics and detrended correspondence analyses (DCA). Fish species richness metrics included total fish species richness, and percentages of endemic species richness, alien species, and fluvial specialist species. Fish species richness decreased significantly with increasing urbanization in BIR (r = -0.82, P = 0.001) and BOS (r = -0.48, P = 0.008). Percentages of endemic species richness decreased significantly with increasing urbanization only in BIR (r = - 0.71, P = 0.001), whereas percentages of fluvial specialist species decreased significantly with increasing urbanization only in BOS (r = -0.56, P = 0.002). Our DCA results for BIR indicate that highly urbanized fish assemblages are composed primarily of largescale stoneroller Campostoma oligolepis, largemouth bass Micropterus salmoides, and creek chub Semotilus atromaculatus, whereas the highly urbanized fish assemblages in BOS are dominated by yellow perch Perca flavescens, bluegill Lefomis macrochirus, yellow bullhead Ameiurus natalis, largemouth bass, pumpkinseed L. gibbosus, brown bullhead A. nebulosus, and redfin pickerel Esox americanus. Differences in fish assemblage responses to urbanization between the two areas appear to be related to differences in nutrient enrichment, habitat alterations, and invasive species. Because species richness can increase or decrease with increasing urbanization, a general response model is not applicable. Instead, response models based on species' life histories, behavior, and autecologies offer greater potential for understanding fish assemblage responses to urbanization. ?? 2005 by the American Fisheries Society.

Heavy metals in fish from the Aleutians: Interspecific and locational differences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, Joanna, E-mail: burger@biology.rutgers.edu; Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ; Consortium for Risk Evaluation with Stakeholder Participation, Vanderbilt University, Nashville, TN 37235

The objectives of this study were to examine levels of arsenic, cadmium, lead, mercury and selenium in edible tissue of seven species of marine fish collected from several Aleutian islands (in 2004) to determine: (1) interspecific differences, (2) locational differences (among Aleutian Islands), (3) size-related differences in any metal levels within a species, and (4) potential risk to the fish or to predators on the fish, including humans. We also compared metals levels to those of three other fish species previously examined in detail, as well as examining metals in the edible tissue of octopus (Octopus dofleini). Octopus did notmore » have the highest levels of any metal. There were significant interspecific differences in all metal levels among the fish species, although the differences were less than an order of magnitude, except for arsenic (mean of 19,500 ppb in Flathead sole, Hippoglossoides elassodon). Significant intraisland variation occurred among the four sites on Amchitka, but there was not a consistent pattern. There were significant interisland differences for some metals and species. Mercury levels increased significantly with size for several species; lead increased significantly for only one fish species; and cadmium and selenium decreased significantly with size for halibut (Hippoglossus stenolepis). The Alaskan Department of Health and Social Services supports unrestricted consumption of most Alaskan fish species for all people, including pregnant women. Most mean metal concentrations were well below the levels known to adversely affect the fish themselves, or predators that consume them (including humans), except for mercury in three fish species (mean levels just below 0.3 ppm), and arsenic in two fish species. However, even at low mercury levels, people who consume fish almost daily will exceed guideline values from the Centers for Disease Control and the Environmental Protection Agency. - Highlights: • Cadmium, lead, mercury and selenium levels differed among 10 fish species from the Aleutians. • Mean Arsenic was as high as 19,500 ppb (flathead sole, Hippoglossoides elassodon). • Mercury levels increased significantly with fish size for several species. • Metal levels were generally below adverse effects levels for fish and their predators. • Mercury and arsenic might pose a risk to human consumers, and require further examination.« less

Fishing down the largest coral reef fish species.

PubMed

Fenner, Douglas

2014-07-15

Studies on remote, uninhabited, near-pristine reefs have revealed surprisingly large populations of large reef fish. Locations such as the northwestern Hawaiian Islands, northern Marianas Islands, Line Islands, U.S. remote Pacific Islands, Cocos-Keeling Atoll and Chagos archipelago have much higher reef fish biomass than islands and reefs near people. Much of the high biomass of most remote reef fish communities lies in the largest species, such as sharks, bumphead parrots, giant trevally, and humphead wrasse. Some, such as sharks and giant trevally, are apex predators, but others such as bumphead parrots and humphead wrasse, are not. At many locations, decreases in large reef fish species have been attributed to fishing. Fishing is well known to remove the largest fish first, and a quantitative measure of vulnerability to fishing indicates that large reef fish species are much more vulnerable to fishing than small fish. The removal of large reef fish by fishing parallels the extinction of terrestrial megafauna by early humans. However large reef fish have great value for various ecological roles and for reef tourism. Copyright © 2014 Elsevier Ltd. All rights reserved.

Functional diversity of non-lethal effects, chemical camouflage, and variation in fish avoidance in colonizing beetles.

PubMed

Resetarits, William J; Pintar, Matthew R

2016-12-01

Predators play an extremely important role in natural communities. In freshwater systems, fish can dominate sorting both at the colonization and post-colonization stage. Specifically, for many colonizing species, fish can have non-lethal, direct effects that exceed the lethal direct effects of predation. Functionally diverse fish species with a range of predatory capabilities have previously been observed to elicit functionally equivalent responses on oviposition in tree frogs. We tested this hypothesis of functional equivalence of non-lethal effects for four predatory fish species, using naturally colonizing populations of aquatic beetles. Among taxa other than mosquitoes, and with the exception of the chemically camouflaged pirate perch, Aphredoderus sayanus, we provide the first evidence of variation in colonization or oviposition responses to different fish species. Focusing on total abundance, Fundulus chrysotus, a gape-limited, surface-feeding fish, elicited unique responses among colonizing Hydrophilidae, with the exception of the smallest and most abundant taxa, Paracymus, while Dytiscidae responded similarly to all avoided fish. Neither family responded to A. sayanus. Analysis of species richness and multivariate characterization of the beetle assemblages for the four fish species and controls revealed additional variation among the three avoided species and confirmed that chemical camouflage in A. sayanus results in assemblages essentially identical to fishless controls. The origin of this variation in beetle responses to different fish is unknown, but may involve variation in cue sensitivity, different behavioral algorithms, or differential responses to species-specific fish cues. The identity of fish species occupying aquatic habitats is crucial to understanding community structure, as varying strengths of lethal and non-lethal effects, as well as their interaction, create complex landscapes of predator effects and challenge the notion of functional equivalence. © 2016 by the Ecological Society of America.

Parasite infestation increases on coral reefs without cleaner fish

NASA Astrophysics Data System (ADS)

Grutter, A. S.; De Brauwer, M.; Bshary, R.; Cheney, K. L.; Cribb, T. H.; Madin, E. M. P.; McClure, E. C.; Meekan, M. G.; Sun, D.; Warner, R. R.; Werminghausen, J.; Sikkel, P. C.

2018-03-01

Mutualisms are pivotal in shaping ecological communities. Iconic images of cleaner fish entering the mouths of predatory fish clients to remove ectoparasites epitomize their mutual benefit. Experimental manipulations of cleaner wrasse reveal declines in fish size and growth, and population abundance and diversity of client fishes in the absence of cleaner wrasse. Fishes grow more slowly and are less abundant and diverse on reefs without cleaner wrasse, both for larger species that are regularly cleaned and have high ectoparasite loads ("attractive species"), and for those smaller species that are rarely cleaned and are rarely infested with parasites ("unattractive species"). We therefore considered whether these previously observed declines in individual and population parameters on reefs without cleaners were related to increased ectoparasite infestation using an attractive species ( Hemigymnus melapterus, Labridae) and an unattractive species ( Pomacentrus amboinensis, Pomacentridae). Traps with these fish as a form of bait were deployed to sample blood-sucking gnathiid ectoparasites (Gnathiidae: Isopoda) on reefs from which cleaners ( Labroides dimidiatus, Labridae) have been removed for 13 yr. Cleaner fish could not enter traps to access the clients/hosts, but gnathiids could enter the traps to infest hosts; thus, this method sampled the indirect effect of cleaners on gnathiid infestation of fish. Infestation was higher on reefs without cleaners than on those with them. The effect was only detected during the daytime when cleaners are active and only on the attractive species ( H. melapterus). Thus, cleaner presence indirectly reduced fish exposure to parasites in a species that is highly susceptible to parasites, but not in one that is rarely infested with parasites. This suggests that cleaner presence indirectly reduces exposure of a common fish species to harmful parasites, which may explain some observed benefits in fishes at this location.

Specific IgE to fish extracts does not predict allergy to specific species within an adult fish allergic population

PubMed Central

2014-01-01

Background Fish is an important cause of food allergy. Studies on fish allergy are scarce and in most cases limited to serological evaluation. Our objective was to study patterns of self-reported allergy and tolerance to different commonly consumed fish species and its correlation to IgE sensitization to the same species. Methods Thirty-eight adult fish allergic patients completed a questionnaire regarding atopy, age of onset and symptoms to 13 commonly consumed fish species in the Netherlands (pangasius, cod, herring, eel, hake, pollock, mackerel, tilapia, salmon, sardine, tuna, plaice and swordfish). Specific IgE to these fish extracts were analyzed by ImmunoCAP. Results Median age of onset of fish allergy was 8.5 years. Severe reactions were reported by the majority of patients (n = 20 (53%) respiratory and of these 20 patients, 6 also had cardiovascular symptoms). After diagnosis, 66% of the patients had eliminated all fish from their diet. Allergy to all species ever tried was reported by 59%. In relation to species ever tried, cod (84%) and herring (79%) were the most frequently reported culprit species while hake (57%) and swordfish (55%) were the least frequent. A positive sIgE (value ≥ 0.35 kUA/L) to the culprit species ranged between 50% (swordfish) and 100% (hake). In tolerant patients, a negative sIgE (value < 0.35 kUA/L) ranged from 0% (hake, pollock and swordfish) to 75% (sardine). For cod, the agreement between sIgE test results and reported allergy or tolerance was 82% and 25%, respectively. Sensitization to cod parvalbumin (Gad c 1) was present in 77% of all patients. Conclusion Serological cross-reactivity between fish species is frequent, but in a significant proportion of patients, clinical relevance appears to be limited to only certain species. A well-taken history or food challenge is required for discrimination between allergy to the different fish species. PMID:25225608

Specific IgE to fish extracts does not predict allergy to specific species within an adult fish allergic population.

PubMed

Schulkes, Karlijn Jg; Klemans, Rob Jb; Knigge, Lidy; de Bruin-Weller, Marjolein; Bruijnzeel-Koomen, Carla Afm; Marknell deWitt, Asa; Lidholm, Jonas; Knulst, André C

2014-01-01

Fish is an important cause of food allergy. Studies on fish allergy are scarce and in most cases limited to serological evaluation. Our objective was to study patterns of self-reported allergy and tolerance to different commonly consumed fish species and its correlation to IgE sensitization to the same species. Thirty-eight adult fish allergic patients completed a questionnaire regarding atopy, age of onset and symptoms to 13 commonly consumed fish species in the Netherlands (pangasius, cod, herring, eel, hake, pollock, mackerel, tilapia, salmon, sardine, tuna, plaice and swordfish). Specific IgE to these fish extracts were analyzed by ImmunoCAP. Median age of onset of fish allergy was 8.5 years. Severe reactions were reported by the majority of patients (n = 20 (53%) respiratory and of these 20 patients, 6 also had cardiovascular symptoms). After diagnosis, 66% of the patients had eliminated all fish from their diet. Allergy to all species ever tried was reported by 59%. In relation to species ever tried, cod (84%) and herring (79%) were the most frequently reported culprit species while hake (57%) and swordfish (55%) were the least frequent. A positive sIgE (value ≥ 0.35 kUA/L) to the culprit species ranged between 50% (swordfish) and 100% (hake). In tolerant patients, a negative sIgE (value < 0.35 kUA/L) ranged from 0% (hake, pollock and swordfish) to 75% (sardine). For cod, the agreement between sIgE test results and reported allergy or tolerance was 82% and 25%, respectively. Sensitization to cod parvalbumin (Gad c 1) was present in 77% of all patients. Serological cross-reactivity between fish species is frequent, but in a significant proportion of patients, clinical relevance appears to be limited to only certain species. A well-taken history or food challenge is required for discrimination between allergy to the different fish species.

Bioaccumulation of selenium from coal fly ash and associated environmental hazards in a freshwater fish community

DOE Office of Scientific and Technical Information (OSTI.GOV)

Besser, J.; Giesy, J.; Brown, R.

1995-12-31

Bioaccumulation of Se by fish from Pigeon River and Pigeon Lake, Michigan, which receive inputs of Se from a coal fly-ash disposal facility, was studied to assess potential hazards of Se toxicity to fish and wildlife. Se concentrations in fish from sites receiving Se inputs from fly ash disposal ponds were significantly greater than concentrations in fish from upstream sites, which were near normal background concentrations. Se bioaccumulation differed substantially among fish species, especially in the most contaminated site, where whole-body Se concentrations for the five species analyzed ranged from 1.4 to 3.8 {micro}g/g (wet wt.). The top predator inmore » the community, northern pike (Esox lucius), had Se concentrations less than those in likely prey species. Among lower-order consumers, Se concentrations were greater in limnetic species (spottail shiner, Notropis hudsonius, and yellow perch, Perca flavescens), than in benthic species (white sucker, Catostomus commersoni, and rock bass, Ambloplites rupestris). Se concentrations in tissues of fish from the lower Pigeon River and Pigeon Lake approached, but did not exceed lowest observable effect concentrations (LOAECs) for Se in tissues of sensitive fish species. However, Se concentrations in several fish species exceeded LOAECs for dietary Se exposure of sensitive species of birds and mammals, suggesting that consumption of fish in these areas may pose a hazard to piscivorous wildlife.« less

Hierarchical spatial structure of stream fish colonization and extinction

USGS Publications Warehouse

Hitt, N.P.; Roberts, J.H.

2012-01-01

Spatial variation in extinction and colonization is expected to influence community composition over time. In stream fish communities, local species richness (alpha diversity) and species turnover (beta diversity) are thought to be regulated by high extinction rates in headwater streams and high colonization rates in downstream areas. We evaluated the spatiotemporal structure of fish communities in streams originally surveyed by Burton and Odum 1945 (Ecology 26: 182-194) in Virginia, USA and explored the effects of species traits on extinction and colonization dynamics. We documented dramatic changes in fish community structure at both the site and stream scales. Of the 34 fish species observed, 20 (59%) were present in both time periods, but 11 (32%) colonized the study area and three (9%) were extirpated over time. Within streams, alpha diversity increased in two of three streams but beta diversity decreased dramatically in all streams due to fish community homogenization caused by colonization of common species and extirpation of rare species. Among streams, however, fish communities differentiated over time. Regression trees indicated that reproductive life-history traits such as spawning mound construction, associations with mound-building species, and high fecundity were important predictors of species persistence or colonization. Conversely, native fishes not associated with mound-building exhibited the highest rates of extirpation from streams. Our results demonstrate that stream fish colonization and extinction dynamics exhibit hierarchical spatial structure and suggest that mound-building fishes serve as keystone species for colonization of headwater streams.

Spatial and temporal repeatability in parasite community structure of tropical fish hosts.

PubMed

Vidal-Martínez, V M; Poulin, R

2003-10-01

An assessment is made of the repeatability of parasite community structure in space for a marine fish, and in space and time for a freshwater fish from south-eastern Mexico. The marine fish species was the red grouper, Epinephelus morio (collected from 9 localities), and the freshwater species was the cichlid, Cichlasoma urophthalmus (collected from 6 localities: including monthly at 2 localities for 1 year, and bimonthly at 1 locality in 1990 and 1999). Pairwise interspecific associations and analyses of nested patterns in the distributions of parasite species among hosts were used in both fish species, with comparisons over time made only with the cichlid. Positive interspecific associations, and nested patterns were noted in some localities for both fish species, and/or at some sampling times for the cichlid fish. However, non-random patterns in the structure of parasite communities in these 2 host species only were observed sporadically. When present, nestedness in both fish species was apparently linked with a positive association between total infection intensities and fish size. Additionally, adjacent localities were more likely to display similar parasite community structure than distant ones. This preliminary result suggests that distance between localities is an important determinant of predictability in parasite community structure.

The campaign to DNA barcode all fishes, FISH-BOL.

PubMed

Ward, R D; Hanner, R; Hebert, P D N

2009-02-01

FISH-BOL, the Fish Barcode of Life campaign, is an international research collaboration that is assembling a standardized reference DNA sequence library for all fishes. Analysis is targeting a 648 base pair region of the mitochondrial cytochrome c oxidase I (COI) gene. More than 5000 species have already been DNA barcoded, with an average of five specimens per species, typically vouchers with authoritative identifications. The barcode sequence from any fish, fillet, fin, egg or larva can be matched against these reference sequences using BOLD; the Barcode of Life Data System (http://www.barcodinglife.org). The benefits of barcoding fishes include facilitating species identification, highlighting cases of range expansion for known species, flagging previously overlooked species and enabling identifications where traditional methods cannot be applied. Results thus far indicate that barcodes separate c. 98 and 93% of already described marine and freshwater fish species, respectively. Several specimens with divergent barcode sequences have been confirmed by integrative taxonomic analysis as new species. Past concerns in relation to the use of fish barcoding for species discrimination are discussed. These include hybridization, recent radiations, regional differentiation in barcode sequences and nuclear copies of the barcode region. However, current results indicate these issues are of little concern for the great majority of specimens.

Ethnoichthyology of the indigenous Truká people, Northeast Brazil.

PubMed

Santos, Carlos Alberto Batista; Alves, Rômulo Romeu Nóbrega

2016-01-06

Historically, fishing is an important activity for riverine communities established along the São Francisco River, including indigenous communities. In the present study, we researched fishing activities in two villages of the Truká ethnic group, both located in the State of Pernambuco along the sub-middle section of the São Francisco River, Northeast Brazil. We recorded the richness and uses of the fished species and the ecological knowledge on these species, the fishing techniques employed and the perception of the indigenous people regarding current environmental impacts on the São Francisco River that influence local fishing. The information was obtained through interviews with 33 Truká fishers (27 men and six women), including 17 interviewees from Central Village (Cabrobó) and 16 from Tapera Village (Orocó). Using five fishing techniques, the interviewees caught 25 fish species, including 21 native and four exotic species. All species are used as food, and two species are used in traditional Truká medicine. The interviewees revealed that fishing currently has less importance in their subsistence. They indicated that this situation is occurring because of several factors, such as the introduction of exotic species, pollution and urbanization, that have impacted the São Francisco River, resulting in a decline of fishing resources. Nevertheless, we found that the indigenous people who are still fishing have a broad knowledge of the habitat and ecology of the target fishing. Although fishing is declining in importance among the Truká, we found that the individuals who are still practicing this activity have a broad knowledge about the habitat and ecology of the target species and apply that knowledge to fishing methods. Knowledge about the ecology of the species and the environmental impacts that have affected them can support basic research on local fish populations and research investigating the environmental impacts, resource management and sustainable exploitation of fisheries resources.

Selenium bioaccumulation and hazards in a fish community affected by coal fly ash effluent

USGS Publications Warehouse

Besser, John M.; Giesy, John P.; Brown, Russell W.; Buell, Julie M.; Dawson, G. A.

1996-01-01

Bioaccumulation of selenium (Se) in the fish community of Pigeon River/Pigeon Lake, which receives inputs of Se from a coal fly ash disposal facility, was studied to assess potential hazards of Se to fish, wildlife, and humans. Se concentrations in fish from sites receiving seepage and effluents from fly ash disposal ponds were significantly greater than those in fish from upstream, where Se concentrations were near background concentrations. Se concentrations differed among fish species, and interspecific variation was greatest at the most contaminated locations. Differences in Se bioaccumulation among fish species were not consistently associated with differences in trophic status. Although Se concentrations in northern pike were consistently less than those in likely prey species, large yellow perch contained Se concentrations as great as those in spottail shiners, their likely prey. Se bioaccumulation may have been influenced by differences in habitat preferences, as limnetic species generally contained greater Se concentrations than benthic species. Se concentrations in fish from the lower Pigeon River and Pigeon Lake did not exceed lowest observable adverse effect concentrations (LOAECs) for Se in tissues of fish species, but exceeded LOAECs for dietary Se exposure of sensitive species of birds and mammals. Human consumption of moderate quantities of fish from the areas studied should not result in excessive Se intake.

Mitochondrial cytochrome b DNA sequence variations: an approach to fish species identification in processed fish products.

PubMed

Pepe, Tiziana; Trotta, Michele; di Marco, Isolina; Cennamo, Paola; Anastasio, Aniello; Cortesi, Maria Luisa

2005-02-01

The identification of fish species in food products is problematic because morphological features of the fish are partially or completely lost during processing. It is important to determine fish origin because of the increasing international seafood trade and because European Community Regulation 104/2000 requires that the products be labeled correctly. Sequence analysis of PCR products from a conserved region of the cytochrome b gene was used to identity fish species belonging to the families Gadidae and Merluccidae in 18 different processed fish products. This method allowed the identification of fish species in all samples. Fish in all of the examined products belonged to these two families, with the exception of one sample of smoked baccalà (salt cod), which was not included in the Gadidae cluster.

Coral reef habitats as surrogates of species, ecological functions, and ecosystem services.

PubMed

Mumby, Peter J; Broad, Kenneth; Brumbaugh, Daniel R; Dahlgren, Craig P; Harborne, Alastair R; Hastings, Alan; Holmes, Katherine E; Kappel, Carrie V; Micheli, Fiorenza; Sanchirico, James N

2008-08-01

Habitat maps are often the core spatially consistent data set on which marine reserve networks are designed, but their efficacy as surrogates for species richness and applicability to other conservation measures is poorly understood. Combining an analysis of field survey data, literature review, and expert assessment by a multidisciplinary working group, we examined the degree to which Caribbean coastal habitats provide useful planning information on 4 conservation measures: species richness, the ecological functions of fish species, ecosystem processes, and ecosystem services. Approximately one-quarter to one-third of benthic invertebrate species and fish species (disaggregated by life phase; hereafter fish species) occurred in a single habitat, and Montastraea-dominated forereefs consistently had the highest richness of all species, processes, and services. All 11 habitats were needed to represent all 277 fish species in the seascape, although reducing the conservation target to 95% of species approximately halved the number of habitats required to ensure representation. Species accumulation indices (SAIs) were used to compare the efficacy of surrogates and revealed that fish species were a more appropriate surrogate of benthic species (SAI = 71%) than benthic species were for fishes (SAI = 42%). Species of reef fishes were also distributed more widely across the seascape than invertebrates and therefore their use as a surrogate simultaneously included mangroves, sea grass, and coral reef habitats. Functional classes of fishes served as effective surrogates of fish and benthic species which, given their ease to survey, makes them a particularly useful measure for conservation planning. Ecosystem processes and services exhibited great redundancy among habitats and were ineffective as surrogates of species. Therefore, processes and services in this case were generally unsuitable for a complementarity-based approach to reserve design. In contrast, the representation of species or functional classes ensured inclusion of all processes and services in the reserve network.

Spatiotemporal patterns of the fish assemblages downstream of the Gezhouba Dam on the Yangtze River.

PubMed

Tao, Jiangping; Gong, Yutian; Tan, Xichang; Yang, Zhi; Chang, Jianbo

2012-07-01

An explicit demonstration of the changes in fish assemblages is required to reveal the influence of damming on fish species. However, information from which to draw general conclusions regarding changes in fish assemblages is insufficient because of the limitations of available approaches. We used a combination of acoustic surveys, gillnet sampling, and geostatistical simulations to document the spatiotemporal variations in the fish assemblages downstream of the Gezhouba Dam, before and after the third impoundment of Three Gorges Reservoir (TGR). To conduct a hydroacoustic identification of individual species, we matched the size distributions of the fishes captured by gillnet with those of the acoustic surveys. An optimum threshold of target strength of -50 dB re 1 m(2) was defined, and acoustic surveys were purposefully extended to the selected fish assemblages (i.e., endemic Coreius species) that was acquired by the size and species selectivity of the gillnet sampling. The relative proportion of fish species in acoustic surveys was allocated based on the composition (%) of the harvest in the gillnet surveys. Geostatistical simulations were likewise used to generate spatial patterns of fish distribution, and to determine the absolute abundance of the selected fish assemblages. We observed both the species composition and the spatial distribution of the selected fish assemblages changed significantly after implementation of new flow regulation in the TGR, wherein an immediate sharp population decline in the Coreius occurred. Our results strongly suggested that the new flow regulation in the TGR impoundment adversely affected downstream fish species, particularly the endemic Coreius species. To determine the factors responsible for the decline, we associated the variation in the fish assemblage patterns with changes in the environment and determined that substrate erosion resulting from trapping practices in the TGR likely played a key role.

[Helminthic fauna of commercial fishes from the Saya-de-Malya bank (Indian Ocean)].

PubMed

Parukhin, A M

1988-01-01

The data on infestation of 8 species of commercial fishes from Saya-de-Malya bank (the Indian Ocean) are presented. 43 helminth species were identified: 10 Monogenea species, 18 trematode, 7 cestode and 8 nematode species. The mature worms are observed to be related to a certain host, whereas the nematode and cestode larvae have wide specificity. High infestation degree by Anisakis larvae is found in fishes, especially in Carangidae. At the bank area fishes are found to be free from Acanthocephala while those Acanthocephala are found in fishes from other areas of the Indian Ocean which may be attributed to the specific diet at the Saya-de-Malya bank. On the whole the helminth fauna of fishes examined at the Saya-de-Malya bank does not demonstrate the endemic pattern. The most specific helminth species were found in some fish species.

Species-specific mercury bioaccumulation in a diverse fish community.

PubMed

Donald, David B; Wissel, Björn; Anas, M U Mohamed

2015-12-01

Mercury bioaccumulation models developed for fish provide insight into the sources and transfer of Hg within ecosystems. Mercury concentrations were assessed for 16 fish species of the western reach of Lake Diefenbaker, Saskatchewan, Canada. For top predators (northern pike, Esox Lucius; walleye, Sander vitreum), Hg concentrations were positively correlated to δ(15)N, and δ(15)N to fish age, suggesting that throughout life these fish fed on organisms with increasingly higher trophic values and Hg concentrations. However, fish mass and/or age were the principal parameters related to Hg concentrations for most species. For 9 common species combined, individual variation in Hg concentration was explained in declining order of importance by fish mass, trophic position (δ(15)N), and fish age. Delta (15)N value was not the leading variable related to Hg concentration for the assemblage, probably because of the longevity of lower--trophic-level species (3 species ≥ 20 yr), substantial overlap in Hg concentration and δ(15)N values for large-bodied fish up to 3000 g, and complex relationships between Hg concentration and δ(15)N among species. These results suggest that the quantity of food (and Hg) consumed each year and converted to fish mass, the quantity of Hg bioaccumulated over years and decades, and trophic position were significant determinants of Hg concentration in Lake Diefenbaker fish. © 2015 SETAC.

Reassociation and hybridization properties of DNAs from several species of fish

USGS Publications Warehouse

Gharrett, A.J.; Simon, R.C.; McIntyre, J.D.

1977-01-01

Reassociation and hybridization properties from spectrophotometric studies of DNAs from 10 species of fish indicate:1. Great diversity in the amounts of repeated sequences in the genomes of different species - more specialized fish had less redundancy.2. Large differences in the complexities of the DNAs - more specialized fish had less information.3. Little homology between sequences of remotely related species but substantial homology between sequences of closely related species.

Composition and diversity of fish species in seagrass bed ecosystem at Muara Binuangeun, Lebak, Banten

NASA Astrophysics Data System (ADS)

Kholis, N.; Patria, M. P.; Soedjiarti, T.

2017-07-01

Research of composition and diversity of fish species in seagrass bed ecosystem at Muara Binuangeun, Lebak, Banten, had been conducted in May and November 2015. Catch per Unit of Effort (CPUE) was used as a method with push net and boat net as fishing gear. Fishing was conducted during low tide. Collected samples were preserved with 10 % Formalin Solution and then being identified in the laboratory. In total, 286 fishes were collected from 17 families and 38 species. Moolgarda sp. was the most relative abundant species (17,13 %) and Istiblennius edentulus was a fish species with the highest relative frequency. Diversity index value of seagrass bed ecosystem was 2,973. Different sampling time showed the different composition of fish, in an example of Arothron immaculatus.

Acute and chronic toxicity of copper to the euryhaline rotifer, Brachionus plicatilis ("L" strain).

PubMed

Arnold, W R; Diamond, R L; Smith, D S

2011-02-01

This article presents data from original research, intended for the use in the development of copper (Cu) criteria for the protection of estuarine and marine organisms and their uses in the United States. Two 48-h static-acute toxicity tests-one with and one without added food-and a 96-h static multigeneration life-cycle test (P1-F2 generations) were performed concurrently using the euryhaline rotifer Brachionus plicatilis ("L" strain) to develop a Cu acute-to-chronic ratio (ACR) for this species. Tests were performed at 15 g/L salinity, at 25°C, and the exposure concentrations of dissolved Cu were verified. Supplemental chemical analyses were performed and reported for the development of a Cu-saltwater biotic ligand model (BLM). Supplemental analyses included alkalinity, calcium, chloride, dissolved organic carbon (DOC), hardness, magnesium, potassium, sodium, and temperature. The acute toxicity test measurement end points were the dissolved Cu median lethal concentration (LC₅₀) values based on rotifer survival. The chronic measurement end points were the dissolved Cu no-observed-effect concentration (NOEC), lowest-observed-effect concentration (LOEC), EC₂₅, EC₂₀, and EC₁₀ based on the intrinsic rate of rotifer population increase (r). The 48-h LC₅₀(Fed), 48-h LC₅₀(Unfed), 96-h NOEC, 96-h LOEC, EC₂₅, EC₂₀, and EC₁₀ were 20.8, 13.4, 6.1, 10.3, 11.7, 10.9, and 8.8 μg Cu/L, respectively. The ACRs were calculated as ratios of each 48-h LC₅₀ value [fed and unfed) and each of the 96-h chronic values (ChV; geometric mean of NOEC and LOEC)], EC₁₀, EC₂₀, and EC₂₅. The ACRs ranged from 1.15 to 2.63.

Importance of plasticity and local adaptation for coping with changing salinity in coastal areas: a test case with barnacles in the Baltic Sea

PubMed Central

2014-01-01

Background Salinity plays an important role in shaping coastal marine communities. Near-future climate predictions indicate that salinity will decrease in many shallow coastal areas due to increased precipitation; however, few studies have addressed this issue. The ability of ecosystems to cope with future changes will depend on species’ capacities to acclimatise or adapt to new environmental conditions. Here, we investigated the effects of a strong salinity gradient (the Baltic Sea system – Baltic, Kattegat, Skagerrak) on plasticity and adaptations in the euryhaline barnacle Balanus improvisus. We used a common-garden approach, where multiple batches of newly settled barnacles from each of three different geographical areas along the Skagerrak-Baltic salinity gradient were exposed to corresponding native salinities (6, 15 and 30 PSU), and phenotypic traits including mortality, growth, shell strength, condition index and reproductive maturity were recorded. Results We found that B. improvisus was highly euryhaline, but had highest growth and reproductive maturity at intermediate salinities. We also found that low salinity had negative effects on other fitness-related traits including initial growth and shell strength, although mortality was also lowest in low salinity. Overall, differences between populations in most measured traits were weak, indicating little local adaptation to salinity. Nonetheless, we observed some population-specific responses – notably that populations from high salinity grew stronger shells in their native salinity compared to the other populations, possibly indicating adaptation to differences in local predation pressure. Conclusions Our study shows that B. improvisus is an example of a true brackish-water species, and that plastic responses are more likely than evolutionary tracking in coping with future changes in coastal salinity. PMID:25038588

Transcriptome and Molecular Pathway Analysis of the Hepatopancreas in the Pacific White Shrimp Litopenaeus vannamei under Chronic Low-Salinity Stress

PubMed Central

Chen, Ke; Li, Erchao; Li, Tongyu; Xu, Chang; Wang, Xiaodan; Lin, Heizhao; Qin, Jian G.; Chen, Liqiao

2015-01-01

The Pacific white shrimp Litopenaeus vannamei is a euryhaline penaeid species that shows ontogenetic adaptations to salinity, with its larvae inhabiting oceanic environments and postlarvae and juveniles inhabiting estuaries and lagoons. Ontogenetic adaptations to salinity manifest in L. vannamei through strong hyper-osmoregulatory and hypo-osmoregulatory patterns and an ability to tolerate extremely low salinity levels. To understand this adaptive mechanism to salinity stress, RNA-seq was used to compare the transcriptomic response of L. vannamei to changes in salinity from 30 (control) to 3 practical salinity units (psu) for 8 weeks. In total, 26,034 genes were obtained from the hepatopancreas tissue of L. vannamei using the Illumina HiSeq 2000 system, and 855 genes showed significant changes in expression under salinity stress. Eighteen top Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were significantly involved in physiological responses, particularly in lipid metabolism, including fatty-acid biosynthesis, arachidonic acid metabolism and glycosphingolipid and glycosaminoglycan metabolism. Lipids or fatty acids can reduce osmotic stress in L. vannamei by providing additional energy or changing the membrane structure to allow osmoregulation in relevant organs, such as the gills. Steroid hormone biosynthesis and the phosphonate and phosphinate metabolism pathways were also involved in the adaptation of L. vannamei to low salinity, and the differential expression patterns of 20 randomly selected genes were validated by quantitative real-time PCR (qPCR). This study is the first report on the long-term adaptive transcriptomic response of L. vannamei to low salinity, and the results will further our understanding of the mechanisms underlying osmoregulation in euryhaline crustaceans. PMID:26147449

75 FR 16738 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-02

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... plan and request for comment. SUMMARY: Notice is hereby given that the Washington Department of Fish... fish, sturgeon, carp, and other species.'' The FMEP describes the management of recreational fisheries...

Surveillance of Total Mercury and Methylmercury Concentrations in Retail Fish.

PubMed

Watanabe, Takahiro; Hayashi, Tomoko; Matsuda, Rieko; Akiyama, Hiroshi; Teshima, Reiko

2017-01-01

Most fish samples contain methylmercury, that the concentrations very greatly according to the fish species. To avoid the adverse health effects of methylmercury while retaining the benefits provided by fish consumption, it is important to select suitable fish species and to control the amount of the fish intake. We surveyed the concentrations of total mercury and methylmercury in 210 retail fish samples classified into 19 fish species by using validated analytical methods. The results of this survey were as follows. The total mercury and methylmercury concentrations were higher than 1 mg/kg in some samples of swordfish and bluefin tuna, which are large predatory fish species. In bluefin tuna and yellowtail, total mercury and methylmercury concentrations in farm-raised fish were lower than those in natural fish. There was a positive correlation between total mercury concentration and methylmercury concentration. Our results indicate that a cut-off value of 0.3 mg/kg total mercury in the screening of fish samples would increase the effectiveness of inspection.

Effect of hyperosmotic conditions on flavin-containing monooxygenase activity, protein and mRNA expression in rat kidney

PubMed Central

Rodríguez-Fuentes, Gabriela; Coburn, Cary; Currás-Collazo, Margarita; Guillén, Gabriel; Schlenk, Daniel

2010-01-01

Flavin-containing monooxigenases (FMOs) are a polymorphic family of drug and pesticide metabolizing enzymes, found in the smooth endoplasmatic reticulum that catalyze the oxidation of soft nucleophilic heteroatom substances to their respective oxides. Previous studies in euryhaline fishes have indicated induction of FMO expression and activity in vivo under hyperosmotic conditions. In this study we evaluated the effect of hypersaline conditions in rat kidney. Male Sprague–Dawley rats were injected intraperitoneal with 3.5 M NaCl at a doses ranging from 0.3 cm3/100 g to 0.6 cm3/100 g in two separate treatments. Three hours after injection, FMO activities and FMO1 protein was examined in the first experiment, and the expression of FMO1 mRNA was measured in the second experiment from kidneys after treatment with NaCl. A positive significant correlation was found between FMO1 protein expression and plasma osmolarity (p < 0.05, r = 0.6193). Methyl-p-tolyl sulfide oxidase showed a statistically significant increase in FMO activity, and a positive correlation was observed between plasma osmolarity and production of FMO1-derived (R)-methyl-p-tolyl sulfoxide (p < 0.05, r = 0.6736). Expression of FMO1 mRNA was also positively correlated with plasma osmolality (p < 0.05, r = 0.8428). Similar to studies in fish, these results suggest that expression and activities of FMOs may be influenced by hyperosmotic conditions in the kidney of rats. PMID:19429252

Climate change vulnerability of native and alien freshwater fishes of California: a systematic assessment approach.

PubMed

Moyle, Peter B; Kiernan, Joseph D; Crain, Patrick K; Quiñones, Rebecca M

2013-01-01

Freshwater fishes are highly vulnerable to human-caused climate change. Because quantitative data on status and trends are unavailable for most fish species, a systematic assessment approach that incorporates expert knowledge was developed to determine status and future vulnerability to climate change of freshwater fishes in California, USA. The method uses expert knowledge, supported by literature reviews of status and biology of the fishes, to score ten metrics for both (1) current status of each species (baseline vulnerability to extinction) and (2) likely future impacts of climate change (vulnerability to extinction). Baseline and climate change vulnerability scores were derived for 121 native and 43 alien fish species. The two scores were highly correlated and were concordant among different scorers. Native species had both greater baseline and greater climate change vulnerability than did alien species. Fifty percent of California's native fish fauna was assessed as having critical or high baseline vulnerability to extinction whereas all alien species were classified as being less or least vulnerable. For vulnerability to climate change, 82% of native species were classified as highly vulnerable, compared with only 19% for aliens. Predicted climate change effects on freshwater environments will dramatically change the fish fauna of California. Most native fishes will suffer population declines and become more restricted in their distributions; some will likely be driven to extinction. Fishes requiring cold water (<22°C) are particularly likely to go extinct. In contrast, most alien fishes will thrive, with some species increasing in abundance and range. However, a few alien species will likewise be negatively affected through loss of aquatic habitats during severe droughts and physiologically stressful conditions present in most waterways during summer. Our method has high utility for predicting vulnerability to climate change of diverse fish species. It should be useful for setting conservation priorities in many different regions.

Climate Change Vulnerability of Native and Alien Freshwater Fishes of California: A Systematic Assessment Approach

PubMed Central

Moyle, Peter B.; Kiernan, Joseph D.; Crain, Patrick K.; Quiñones, Rebecca M.

2013-01-01

Freshwater fishes are highly vulnerable to human-caused climate change. Because quantitative data on status and trends are unavailable for most fish species, a systematic assessment approach that incorporates expert knowledge was developed to determine status and future vulnerability to climate change of freshwater fishes in California, USA. The method uses expert knowledge, supported by literature reviews of status and biology of the fishes, to score ten metrics for both (1) current status of each species (baseline vulnerability to extinction) and (2) likely future impacts of climate change (vulnerability to extinction). Baseline and climate change vulnerability scores were derived for 121 native and 43 alien fish species. The two scores were highly correlated and were concordant among different scorers. Native species had both greater baseline and greater climate change vulnerability than did alien species. Fifty percent of California’s native fish fauna was assessed as having critical or high baseline vulnerability to extinction whereas all alien species were classified as being less or least vulnerable. For vulnerability to climate change, 82% of native species were classified as highly vulnerable, compared with only 19% for aliens. Predicted climate change effects on freshwater environments will dramatically change the fish fauna of California. Most native fishes will suffer population declines and become more restricted in their distributions; some will likely be driven to extinction. Fishes requiring cold water (<22°C) are particularly likely to go extinct. In contrast, most alien fishes will thrive, with some species increasing in abundance and range. However, a few alien species will likewise be negatively affected through loss of aquatic habitats during severe droughts and physiologically stressful conditions present in most waterways during summer. Our method has high utility for predicting vulnerability to climate change of diverse fish species. It should be useful for setting conservation priorities in many different regions. PMID:23717503

77 FR 67796 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-14

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS..., Assistant Regional Director of the U.S. Fish and Wildlife Service (FWS), in accordance with the Endangered...-226) governing listed fish and wildlife permits. Species Covered in This Notice This notice is...

Seasonal variation of assemblage and feeding guild structure of fish species in a boreal tidal basin

NASA Astrophysics Data System (ADS)

Kellnreitner, Florian; Pockberger, Moritz; Asmus, Harald

2012-08-01

Species composition, abundance, feeding relationships and guild structure of the fish assemblage in the Sylt-Rømø bight, a tidal basin in the northern Wadden Sea, were investigated to show seasonal differences and the importance of functional groups in this area. The tidal flats and in shallow subtidal areas were sampled using a beach seine and a bottom trawl net was used for deeper subtidal areas and tidal gullies. Species richness of fish was highest in summer where 26 species were caught, while the lowest richness was recorded in winter (17 species). Clear differences in species richness and abundance were found between shallow areas and deeper parts of the bight. Clupea harengus and Ammodytes tobianus were the most abundant species in deeper areas, while Pomatoschistus microps and Pomatoschistus minutus dominated shallower waters. Gut contents of 27 fish species were identified and the guild structure analyzed by UPGMA clustering of niche overlaps. Calanoid copepods (19.9%), Crangon crangon (18.2%) and mysid shrimps (8.4%) were the most abundant prey items of all fish species combined. Seven feeding guilds were present in the fall and winter, and eight and six in spring and summer, respectively. Fish feeding on calanoid copepods and C. crangon were present year round, whereas the occurrence of other guilds varied between seasons. Species composition of prey changed through seasons and, for some fish species, even the feeding mode itself varied with season. Most noticeable, 11 fish species changed guilds between seasons. We found a convergence in summer towards abundant prey items, whereas in winter diet overlap was lower. This is the first investigation of guild structure of almost all fish species present in a Wadden Sea area, and shows that consideration of seasonal differences is essential when determining feeding relationships of fish in temperate areas.

Characterization of the Cultivable Gut Microflora in Wild-Caught 
Mediterranean Fish Species.

PubMed

Jammal, Ahmad; Bariche, Michel; Zu Dohna, Heinrich; Kambris, Zakaria

2017-05-01

Microflora of the gastrointestinal tract plays important roles in food digestion, nutrient absorption and in host defense against ingested pathogens. Several studies have focused on the microflora of farmed fishes, but the gut flora of wild fishes remains poorly characterized. The aim of this work was to provide an overview of the bacteria colonizing the gut of wild-caught fishes and to determine whether some bacterial species can be pathogenic. We isolated cultivable bacteria from fifteen wild-caught Mediterranean fish species corresponding to different habitat, diet and origin. Bacterial species identity was determined by 16s rRNA gene sequencing for the 61 isolates. The potential pathogenicity of isolated bacteria was investigated using fruit fly (Drosophila melanogaster) and zebrafish (Danio rerio) as model organisms. Two bacterial strains (Serratia sp. and Aeromonas salmonicida) were lethal when microinjected to Drosophila, while zebrafish did not develop any disease when exposed to any of 34 isolated bacterial strains. However, it was interesting to note that two bacterial strains (Shewanella and Arthrobacter) isolated from marine fishes were able to colonize the guts of freshwater zebrafish. The results of this study give an overview of the bacterial species found in the guts of wild fishes living off Beirut seashore. It shows that some parameters believed to be limiting factors to host-gut colonization by bacteria can be overcome by some species. This pilot study could be extended by sampling a larger number of fish species with several specimens per fish species, and by identifying uncultivable bacteria that reside in the fish guts. Our results may have implications for the utilization of certain bacterial species in fish farming or their use as bio-indicators for water and/or food quality.

Vitamin A intoxication from reef fish liver consumption in Bermuda.

PubMed

Dewailly, E; Rouja, P; Schultz, E; Julien, P; Tucker, T

2011-09-01

We report three historical cases of severe vitamin A intoxication in anglers who had consumed reef fish liver caught in Bermuda. The subsequent analyses of 35 fish livers from seven different fish species revealed that very high concentrations of vitamin A exist in tropical fish liver, even in noncarnivorous fish species. Large variations in concentrations were observed between specimens and between species. The angling population and (especially) pregnant women should be advised of this potential health threat.

Seasonal variation in species composition and abundance of demersal fish and invertebrates in a Seagrass Natural Reserve on the eastern coast of the Shandong Peninsula, China

NASA Astrophysics Data System (ADS)

Xu, Qiang; Guo, Dong; Zhang, Peidong; Zhang, Xiumei; Li, Wentao; Wu, Zhongxin

2016-03-01

Seagrass habitats are structurally complex ecosystems, which support high productivity and biodiversity. In temperate systems the density of seagrass may change seasonally, and this may influence the associated fish and invertebrate community. Little is known about the role of seagrass beds as possible nursery areas for fish and invertebrates in China. To study the functioning of a seagrass habitat in northern China, demersal fish and invertebrates were collected monthly using traps, from February 2009 to January 2010. The density, leaf length and biomass of the dominant seagrass Zostera marina and water temperature were also measured. The study was conducted in a Seagrass Natural Reserve (SNR) on the eastern coast of the Shandong Peninsula, China. A total of 22 fish species and five invertebrate species were recorded over the year. The dominant fish species were Synechogobius ommaturus, Sebastes schlegelii, Pholis fangi, Pagrus major and Hexagrammos otakii and these species accounted for 87% of the total number of fish. The dominant invertebrate species were Charybdis japonica and Octopus variabilis and these accounted for 98% of the total abundance of invertebrates. There was high temporal variation in species composition and abundance. The peak number of fish species occurred in August-October 2009, while the number of individual fish and biomass was highest during November 2009. Invertebrate numbers and biomass was highest in March, April, July and September 2009. Temporal changes in species abundance of fishes and invertebrates corresponded with changes in the shoot density and leaf length of the seagrass, Zostera marina.

Threats posed by artisanal fisheries to the reproduction of coastal fish species in a Mediterranean marine protected area

NASA Astrophysics Data System (ADS)

Lloret, J.; Muñoz, M.; Casadevall, M.

2012-11-01

Artisanal fisheries are frequently considered as a sustainable activity compatible with the conservation objectives of marine protected areas (MPAs). Few studies have examined the impacts of these fisheries on the reproductive potential of exploited fish species within the marine reserves. This study evaluated the potential impact of artisanal fishing on the reproduction of coastal fish species in a Mediterranean MPA through onboard sampling from January 2008 to December 2010. Eleven sex-changing fish species constituted an important part of the catch (20% overall and up to 60% of the total gill net catch) and, in five of them, most individuals were of one sex. Artisanal fishing can negatively affect the sustainability of those coastal fishes showing sex reversal, particularly the protogynous ones such as Diplodus cervinus and Epinephelus marginatus, as well as the species with complex mating systems (e.g. some sparids, labrids and scorpaenids). In all species the average size for the individuals captured was above the minimum landing size (where this exists), but in four species (Conger conger, Diplodus puntazzo, Sphyraena spp. and Sparus aurata) it was below the size of first maturity (L50). Results show that sex and size selection by artisanal fishing not only can have an impact on the reproduction of coastal fish species but may also be exacerbating rather than reducing the impact of fishing on coastal resources. Thus, new management actions need to be urgently implemented in the MPAs where artisanal fisheries are allowed to operate in order to protect the reproductive potential of these species, particularly those showing a complicated reproductive strategy.

Characteristic Features and Contributory Factors in Fatal Ciguatera Fish Poisoning—Implications for Prevention and Public Education

PubMed Central

Chan, Thomas Y. K.

2016-01-01

In this review, the main objective was to describe the characteristic features of fatal ciguatera fish poisoning and identify contributory factors, with a view to promote prevention and public education. Ciguatera-related deaths, although rare, have been reported from the Pacific, Caribbean, and Indian Ocean regions. The clinical features were generally dominated by convulsions and coma, with various focal neurological signs. Several contributory factors could be identified, including consumption of ciguatoxin (CTX)-rich fish parts (viscera and head) in larger amounts, the most ciguatoxic fish species (e.g., Gymnothorax flavimarginatus) and reef fish collected after storms and individuals' susceptibility. Mass ciguatera fish poisoning with mortalities also occurred when G. flavimarginatus and other ciguatoxic fish species were shared in gatherings and parties. The characteristic features of fatal ciguatera fish poisoning must be recognized early. The public should be repeatedly reminded to avoid eating the most ciguatoxic fish species and the CTX-rich parts of reef fish. To prevent mass poisoning in gatherings and parties, the most ciguatoxic fish species and potentially toxic fish species must be avoided. Particularly after hits by disastrous storms, it is important to monitor the toxicity of reef fish and the incidence rates of ciguatera. PMID:26787145

Characteristic Features and Contributory Factors in Fatal Ciguatera Fish Poisoning--Implications for Prevention and Public Education.

PubMed

Chan, Thomas Y K

2016-04-01

In this review, the main objective was to describe the characteristic features of fatal ciguatera fish poisoning and identify contributory factors, with a view to promote prevention and public education. Ciguatera-related deaths, although rare, have been reported from the Pacific, Caribbean, and Indian Ocean regions. The clinical features were generally dominated by convulsions and coma, with various focal neurological signs. Several contributory factors could be identified, including consumption of ciguatoxin (CTX)-rich fish parts (viscera and head) in larger amounts, the most ciguatoxic fish species (e.g.,Gymnothorax flavimarginatus) and reef fish collected after storms and individuals' susceptibility. Mass ciguatera fish poisoning with mortalities also occurred when G. flavimarginatus and other ciguatoxic fish species were shared in gatherings and parties. The characteristic features of fatal ciguatera fish poisoning must be recognized early. The public should be repeatedly reminded to avoid eating the most ciguatoxic fish species and the CTX-rich parts of reef fish. To prevent mass poisoning in gatherings and parties, the most ciguatoxic fish species and potentially toxic fish species must be avoided. Particularly after hits by disastrous storms, it is important to monitor the toxicity of reef fish and the incidence rates of ciguatera. © The American Society of Tropical Medicine and Hygiene.

[Species composition and distribution patterns of ichthyoplankton within and outside artificial reefs in Qingshan Bay, Qingdao, China].

PubMed

Guo, Shu Xin; Gao, Dong Kui; Zhang, Xiu Mei; Li, Wen Tao; Zhang, Pei Dong

2017-06-18

To assess the fish attraction and shelter effects of the artificial reefs in Qingshan Bay of Qingdao, the species composition and distribution patterns of ichthyoplankton in artificial reefs were investigated using vertical and horizontal tows in 2014 and 2015. In total, 7306 fish eggs and 52 fish larvae, belonging to 4 orders, 9 families, 11 genera and 12 species, were collected during 7 cruises in spring, summer and autumn of 2014. In 2015, 10373 eggs and 159 fish larvae, belonging to 6 orders, 11 families, 14 genera and 15 species, were collected in the same period as in 2014. Perciformes were the majority for both fish eggs and larvae collected during the two surveys, followed by Pleuronectiformes. Among fish eggs, Sillago japonica and Cynoglossus joyneri were the most dominant species. Among fish larvae, S. japonica exhibited the highest dominance but was not the dominant species. The high dominant species in both fish eggs and larvae appeared alternately in diffe-rent seasons. The Margalef richness index (R), Shannon diversity index (H) and Pielou evenness index (J) of ichthyoplankton community were low during the spring, summer, and autumn, showing an instable community structure of ichthyoplankton. The average trophic level of adult fish corresponding to the ichthyoplankton collected in the two years were 3.71 and 3.78, respectively, and both belonged to low carnivorous fish of third trophic level. All the species were either warm-tempe-rate species or warm-water species, which was coincident with the warm-temperate zone characteristic. Comprehensive analysis showed that the biodiversity of the ichthyoplankton community within the artificial reef areas was higher than that outside the artificial reef areas, which might be linked to flow velocity, flow field characteristics, or spatial heterogeneity of artificial reef areas.

Abiotic and biotic controls of cryptobenthic fish assemblages across a Caribbean seascape

USGS Publications Warehouse

Harborne, A.R.; Jelks, H.L.; Smith-Vaniz, W.F.; Rocha, L.A.

2012-01-01

The majority of fish studies on coral reefs consider only non-cryptic species and, despite their functional importance, data on cryptic species are scarce. This study investigates inter-habitat variation in Caribbean cryptobenthic fishes by re-analysing a comprehensive data set from 58 rotenone stations around Buck Island, U.S. Virgin Islands. Boosted regression trees were used to associate the density and diversity of non-piscivorous cryptobenthic fishes, both in the entire data set and on reef habitats alone, with 14 abiotic and biotic variables. The study also models the habitat requirements of the three commonest species. Dead coral cover was the first or second most important variable in six of the eight models constructed. For example, within the entire data set, the number of species and total fish density increased approximately linearly with increasing dead coral cover. Dead coral was also important in multivariate analyses that discriminated 10 assemblages within the entire data set. On reef habitats, the number of species and total fish density increased dramatically when dead coral exceeded ~55 %. Live coral cover was typically less important for explaining variance in fish assemblages than dead coral, but live corals were important for maintaining high fish diversity. Coral species favoured by cryptobenthic species may be particularly susceptible to mortality, but dead coral may also provide abundant food and shelter for many fishes. Piscivore density was a key variable in the final models, but typically increased with increasing cryptobenthic fish diversity and abundance, suggesting both groups of fishes are responding to the same habitat variables. The density of territorial damselfishes reduced the number of cryptobenthic fish species on reef habitats. Finally, habitats delineated by standard remote sensing techniques supported distinct cryptobenthic fish assemblages, suggesting that such maps can be used as surrogates of general patterns of cryptic fish biodiversity in conservation planning.

Fish species identification using PCR-RFLP analysis and lab-on-a-chip capillary electrophoresis: application to detect white fish species in food products and an interlaboratory study.

PubMed

Dooley, John J; Sage, Helen D; Clarke, Marie-Anne L; Brown, Helen M; Garrett, Stephen D

2005-05-04

Identification of 10 white fish species associated with U.K. food products was achieved using PCR-RFLP of the mitochondrial cytochrome b gene. Use of lab-on-a-chip capillary electrophoresis for end-point analysis enabled accurate sizing of DNA fragments and identification of fish species at a level of 5% (w/w) in a fish admixture. One restriction enzyme, DdeI, allowed discrimination of eight species. When combined with NlaIII and HaeIII, specific profiles for all 10 species were generated. The method was applied to a range of products and subjected to an interlaboratory study carried out by five U.K. food control laboratories. One hundred percent correct identification of single species samples and six of nine admixture samples was achieved by all laboratories. The results indicated that fish species identification could be carried out using a database of PCR-RFLP profiles without the need for reference materials.

Effects of reservoir impoundment on fish assemblages in the Wujiang River of China

NASA Astrophysics Data System (ADS)

Zhu, D.; Yang, Z.

2016-08-01

Fishery catches were investigated during the spring and autumn in the period 2006-2010. The fish assemblages’ composition and dynamics were analysed and compared under the pressure of the Pengshui Reservoir impoundment. A total of 101 species were sampled in the lower Wujiang River. 78 species and 83 species were found in the upper and the lower reaches, respectively. After impoundment there were five species in the Yanhe branch and nine species in the Pengshui branch. The abundance of species was higher in the Pengshui than in the Yanhe. Fish abundance did not change in the first year of impoundment (2008) in the Lujiao- Gongtan reach, but it dramatically declined by 45.95% in 2009. The fish were subdivided into three groups and two ecotypes according to their time-series appearance in fish catches and their habitat preference. Species composition changed significantly with decreases in numbers of lotic species. Fish assemblages responded more rapidly and dramatically to impoundment in the reservoir section than the section below the Pengshui Dam.

Euryhaline preferences of the decapod crab Mioplax socialis enabled it to survive during the Badenian/Sarmatian extinction (Miocene) in the Central Paratethys

PubMed Central

Mandic, Oleg; Harzhauser, Mathias; Ledvák, Peter

2017-01-01

Although decapod crustaceans of the Central Paratethys were diverse during the Badenian (Langhian–Early Serravallian), a dramatic drop in their diversity occurred at the boundary with the Sarmatian. A crab Mioplax socialis is one of the few decapods reported from the Lower Sarmatian (Mohrensternia Zone) of the Paratethys. Until now, this species has been known from only a handful of specimens from Austria, Croatia and Bulgaria (Central Paratethys), and its systematics and ecology remain poorly known. Here, on the basis of new specimens from the Sarmatian tuffitic clays of the Stretava Formation (Skároš, Eastern Slovakia) we confirm that this species belongs to the subfamily Chasmocarcininae. The diagnostic characters of the male sternum that allow this classification are reported for the first time. The molluscan assemblage co-occurring with M. socialis demonstrate that this species tolerated conditions with variable salinity. Its tolerance of a broad range of salinity regimes may thus explain its survival across the Badenian–Sarmatian extinction event. Preservation of near-complete and fully articulated individuals of M. socialis suggests calm conditions and short residence times on the sediment-water interface. PMID:28239258

Threatened fish and fishers along the Brazilian Atlantic Forest Coast.

PubMed

Begossi, Alpina; Salivonchyk, Svetlana; Hallwass, Gustavo; Hanazaki, Natalia; Lopes, Priscila F M; Silvano, Renato A M

2017-12-01

Small-scale fisheries of the Brazilian Atlantic Forest Coast (BAFC) depend on fish resources for food and income. Thus, if the catch diminishes or if fish species that are a target for fishers are overexploited or impacted, this could affect fishers' livelihoods. The exclusion of threatened fish species from the catch is believed to be a threat to small-scale fisheries, which is likely to be the case along the BAFC. Many fish species are currently listed as threatened or vulnerable, whereas there is not enough biological information available to determine the status of the majority of the other species. Failure to protect the BAFC biodiversity might negatively impact fishers' income and the regional economy of local small-scale fisheries. We collected data from 1986 to 2009 through 347 interviews and 24-h food recall surveys at seven southeastern coastal sites of the Atlantic Forest. We show that important species of consumed fish are currently threatened: of the 65 species mentioned by fishers as the most consumed fishes, 33% are decreasing and 54% have an unknown status. Thus, biological and ecological data for BAFC marine species are urgently needed, along with co-management, to promote fish conservation.

Immobilization thresholds of electrofishing relative to fish size

USGS Publications Warehouse

Dolan, C.R.; Miranda, L.E.

2003-01-01

Fish size and electrical waveforms have frequently been associated with variation in electrofishing effectiveness. Under controlled laboratory conditions, we measured the electrical power required by five electrical waveforms to immobilize eight fish species of diverse sizes and shapes. Fish size was indexed by total body length, surface area, volume, and weight; shape was indexed by the ratio of body length to body depth. Our objectives were to identify immobilization thresholds, elucidate the descriptors of fish size that were best associated with those immobilization thresholds, and determine whether the vulnerability of a species relative to other species remained constant across electrical treatments. The results confirmed that fish size is a key variable controlling the immobilization threshold and further suggested that the size descriptor best related to immobilization is fish volume. The peak power needed to immobilize fish decreased rapidly with increasing fish volume in small fish but decreased slowly for fish larger than 75-100 cm 3. Furthermore, when we controlled for size and shape, different waveforms did not favor particular species, possibly because of the overwhelming effect of body size. Many of the immobilization inconsistencies previously attributed to species might simply represent the effect of disparities in body size.

Checklist of the marine and estuarine fishes of Madang District, Papua New Guinea, western Pacific Ocean, with 820 new records.

PubMed

Fricke, Ronald; Allen, Gerald R; Andréfouët, Serge; Chen, Wei-Jen; Hamel, Mélanie A; Laboute, Pierre; Mana, Ralph; Hui, Tan Heok; Uyeno, Daisuke

2014-06-08

A checklist of the marine and estuarine fishes of Madang District is presented, combining both previous and new records. After the recent PAPUA NIUGINI 2012 expedition, a total of 1337 species in 129 families have been recorded from the region. One species and one family is not native (Cichlidae: Oreochromis mossambicus), but has been introduced. The native fish fauna of Madang therefore consists of 1336 species in 128 families. The largest families are the Gobiidae, Labridae, Pomacentridae, Apogonidae, Serranidae, Blenniidae, Chaetodontidae, Syngnathidae and Muraenidae, Scorpaenidae and Lutjanidae, Myctophidae, Acanthuridae, Scaridae, Holocentridae, Carangidae, Pomacanthidae and Tetraodontidae, and Caesionidae. A total of 820 fish species (61.4 % of the total marine and estuarine fish fauna) are recorded from Madang for the first time. The fish fauna of Madang includes a total of 187 species of transitional waters and 1326 species in marine habitats. A total of 156 species of the marine or estuarine species also occurs in freshwater. Zoogeographically, 1271 species have a wide distribution range, most frequently a broad Indo-West Pacific distribution. Among the remaining species, only 8 are endemic to Madang District. Anthropogenic threats to the fish fauna and habitats of Madang District include extensive fishing in Madang Lagoon, sometimes with destructive fishing practices; the discharge of untreated sewage of human settlements, mining and industrial developments into the lagoon and nearby oceanic habitats; and destruction of mangrove habitats by extensive construction work on the shores. These anthropogenic threats may call for conservation and monitoring measures in the near future.

Habitat use by fishes in coral reefs, seagrass beds and mangrove habitats in the Philippines.

PubMed

Honda, Kentaro; Nakamura, Yohei; Nakaoka, Masahiro; Uy, Wilfredo H; Fortes, Miguel D

2013-01-01

Understanding the interconnectivity of organisms among different habitats is a key requirement for generating effective management plans in coastal ecosystems, particularly when determining component habitat structures in marine protected areas. To elucidate the patterns of habitat use by fishes among coral, seagrass, and mangrove habitats, and between natural and transplanted mangroves, visual censuses were conducted semiannually at two sites in the Philippines during September and March 2010-2012. In total, 265 species and 15,930 individuals were recorded. Species richness and abundance of fishes were significantly higher in coral reefs (234 species, 12,306 individuals) than in seagrass (38 species, 1,198 individuals) and mangrove (47 species, 2,426 individuals) habitats. Similarity tests revealed a highly significant difference among the three habitats. Fishes exhibited two different strategies for habitat use, inhabiting either a single (85.6% of recorded species) or several habitats (14.4%). Some fish that utilized multiple habitats, such as Lutjanus monostigma and Parupeneus barberinus, showed possible ontogenetic habitat shifts from mangroves and/or seagrass habitats to coral reefs. Moreover, over 20% of commercial fish species used multiple habitats, highlighting the importance of including different habitat types within marine protected areas to achieve efficient and effective resource management. Neither species richness nor abundance of fishes significantly differed between natural and transplanted mangroves. In addition, 14 fish species were recorded in a 20-year-old transplanted mangrove area, and over 90% of these species used multiple habitats, further demonstrating the key role of transplanted mangroves as a reef fish habitat in this region.

The times are changing: temporal shifts in patterns of fish invasions in central European fresh waters.

PubMed

Rabitsch, W; Milasowszky, N; Nehring, S; Wiesner, C; Wolter, C; Essl, F

2013-01-01

This study examines the invasion history of alien fish species based on exhaustive national data sets on fish invasions of two contiguous central European countries (Germany and Austria). Fifteen alien fish species are currently established in both countries, constituting 14 and 17% of the total freshwater fish fauna of Germany and Austria, respectively. In both countries, six alien species are present, but not established. The status of five alien species in Germany and three species in Austria remains unknown. Accumulation rates of alien fish species have increased in recent decades with >50% of them reported after 1971. North America and Asia were the primary sources of alien fish species in Germany and Austria up to the 1980s, whereas European species of Ponto-Caspian origin dominate now. Fisheries (including aquaculture) and the animal trade were responsible for most earlier introductions, whereas waterways were the main pathway for recent invaders. The extent of the spatial distribution of alien species was positively correlated with residence time, i.e. the time elapsed since the first national record. Different thermal preferences of early invaders (mostly coldwater species) and new invaders (typically warmwater adapted) may benefit the latter in the face of climate change. It is concluded that new challenges for alien fish management arise and that ecosystem-based approaches as endorsed by the E.U. Water Framework Directive (maintaining or restoring good ecological status of rivers and streams) should become the centrepiece of river management in Europe. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Habitat Use by Fishes in Coral Reefs, Seagrass Beds and Mangrove Habitats in the Philippines

PubMed Central

Honda, Kentaro; Nakamura, Yohei; Nakaoka, Masahiro; Uy, Wilfredo H.; Fortes, Miguel D.

2013-01-01

Understanding the interconnectivity of organisms among different habitats is a key requirement for generating effective management plans in coastal ecosystems, particularly when determining component habitat structures in marine protected areas. To elucidate the patterns of habitat use by fishes among coral, seagrass, and mangrove habitats, and between natural and transplanted mangroves, visual censuses were conducted semiannually at two sites in the Philippines during September and March 2010–2012. In total, 265 species and 15,930 individuals were recorded. Species richness and abundance of fishes were significantly higher in coral reefs (234 species, 12,306 individuals) than in seagrass (38 species, 1,198 individuals) and mangrove (47 species, 2,426 individuals) habitats. Similarity tests revealed a highly significant difference among the three habitats. Fishes exhibited two different strategies for habitat use, inhabiting either a single (85.6% of recorded species) or several habitats (14.4%). Some fish that utilized multiple habitats, such as Lutjanus monostigma and Parupeneus barberinus, showed possible ontogenetic habitat shifts from mangroves and/or seagrass habitats to coral reefs. Moreover, over 20% of commercial fish species used multiple habitats, highlighting the importance of including different habitat types within marine protected areas to achieve efficient and effective resource management. Neither species richness nor abundance of fishes significantly differed between natural and transplanted mangroves. In addition, 14 fish species were recorded in a 20-year-old transplanted mangrove area, and over 90% of these species used multiple habitats, further demonstrating the key role of transplanted mangroves as a reef fish habitat in this region. PMID:23976940

Experimental study to control the upstream migration of invasive alien fish species by submerged weir

NASA Astrophysics Data System (ADS)

Sakuma, Masami; Kunimatsu, Fumihiro; Tsuchiya, Taku; Kawamura, Makiko; Fujita, Hiroshi

Largemouth bass and Bluegill, major invasive alien fish species in Japan, have been extending their habitat ranges over not only Lake Biwa and the lagoons but also surrounding waters connected to them through small rivers and canals. Their increasing number is bringing about the reduction in the number of native fish species. To prevent the spread of these alien species through small rivers and canals during breeding season of the native fish (crucian carp), this study experimentally examined the effect of a submerged weir on controlling upstream migration of the alien species and the native fish. As a result of the experiment, the ratio of the alien species migrating upstream decreased as the weir height rose, whereas the ratio did not show the same trend in the case of the native fish. The ratio of the alien species also decreased as the overflow velocity over the weir rose. On the other hand, the ratio of the native fish increased as the overflow velocity rose up to 1.0m/s and decreased thereafter. These results suggest that the submerged weir may control upstream migration of the alien species to surrounding waters through small rivers and canals without interfering with the reproductive migration of the native fish.

Extinction, survival or recovery of large predatory fishes

PubMed Central

Myers, Ransom A.; Worm, Boris

2005-01-01

Large predatory fishes have long played an important role in marine ecosystems and fisheries. Overexploitation, however, is gradually diminishing this role. Recent estimates indicate that exploitation has depleted large predatory fish communities worldwide by at least 90% over the past 50–100 years. We demonstrate that these declines are general, independent of methodology, and even higher for sensitive species such as sharks. We also attempt to predict the future prospects of large predatory fishes. (i) An analysis of maximum reproductive rates predicts the collapse and extinction of sensitive species under current levels of fishing mortality. Sensitive species occur in marine habitats worldwide and have to be considered in most management situations. (ii) We show that to ensure the survival of sensitive species in the northwest Atlantic fishing mortality has to be reduced by 40–80%. (iii) We show that rapid recovery of community biomass and diversity usually occurs when fishing mortality is reduced. However, recovery is more variable for single species, often because of the influence of species interactions. We conclude that management of multi-species fisheries needs to be tailored to the most sensitive, rather than the more robust species. This requires reductions in fishing effort, reduction in bycatch mortality and protection of key areas to initiate recovery of severely depleted communities. PMID:15713586

Extinction, survival or recovery of large predatory fishes.

PubMed

Myers, Ransom A; Worm, Boris

2005-01-29

Large predatory fishes have long played an important role in marine ecosystems and fisheries. Overexploitation, however, is gradually diminishing this role. Recent estimates indicate that exploitation has depleted large predatory fish communities worldwide by at least 90% over the past 50-100 years. We demonstrate that these declines are general, independent of methodology, and even higher for sensitive species such as sharks. We also attempt to predict the future prospects of large predatory fishes. (i) An analysis of maximum reproductive rates predicts the collapse and extinction of sensitive species under current levels of fishing mortality. Sensitive species occur in marine habitats worldwide and have to be considered in most management situations. (ii) We show that to ensure the survival of sensitive species in the northwest Atlantic fishing mortality has to be reduced by 40-80%. (iii) We show that rapid recovery of community biomass and diversity usually occurs when fishing mortality is reduced. However, recovery is more variable for single species, often because of the influence of species interactions. We conclude that management of multi-species fisheries needs to be tailored to the most sensitive, rather than the more robust species. This requires reductions in fishing effort, reduction in bycatch mortality and protection of key areas to initiate recovery of severely depleted communities.

77 FR 23463 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-19

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... is for issuance of an Endangered Species Act section 10(a)(1)(A) permit to US Fish and Wildlife Service to collect Central Valley spring-run Chinook salmon eggs and juveniles from the Feather River Fish...

78 FR 69992 - Guidance for Industry on Purchasing Reef Fish Species Associated With the Hazard of Ciguatera...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-22

.... FDA-2013-D-0269] Guidance for Industry on Purchasing Reef Fish Species Associated With the Hazard of Ciguatera Fish Poisoning; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice of... guidance for industry entitled ``Guidance for Industry: Purchasing Reef Fish Species Associated with the...

78 FR 18273 - Draft Guidance for Industry on Purchasing Reef Fish Species Associated With the Hazard of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

.... FDA-2013-D-0269] Draft Guidance for Industry on Purchasing Reef Fish Species Associated With the Hazard of Ciguatera Fish Poisoning; Availability AGENCY: Food and Drug Administration, HHS. ACTION... availability of a draft guidance entitled ``Guidance for Industry: Purchasing Reef Fish Species Associated With...

[Checklist of fishes of Yunnan].

PubMed

Chen, Xiao-Yong

2013-08-01

Based on extant literatures and taking into accounts updated results of taxonomy and phylogeny, we have updated this checklist of fishes present in Yunnan, including the number of taxa and drainage areas. As of 2013, there were 13 orders, 42 families, 198 genera and 620 valid species recorded in Yunnan Province, of which 586 were native species, 34 alien species, 254 species endemic to Yunnan, and 152 species only occuring in Yunnan within China. The number of species in Yunnan accounts for 39.17% of China's total fish species (of which there are 1 583 recorded freshwater fish species according to data present in Fishbase), and of these 6 families and 66 genera only occur in Yunnan. The number of fish species of the six major drainages in Yunnan were as follows: 202 in Pearl River, 183 in Lancangjiang River (upper Mekong), 142 in Jinshajiang River (upper Yangtze), 120 in Red River, 84 in Irrawaddy Drainage, 77 in Nujiang-Salween Drainage. There are also 99 endangered species of fish occurring in Yunnan, among them 23 species protected by the national and/or the provincial government, including 2 species of national key protected animal class one, 4 species of national key protected animal class two, 17 species of Yunnan provincial protected animal. Totally, 43 species were listed in China Red Data Book of Endangered Animals, Pisces; 73 species were listed in China Species Red List Vol. 1; 50 species were listed in endangered categories of IUCN Red List; and 3 species were listed in the Appendix 2 of CITES. The Chinese name, Latin name, synomyns, distribution and literatures of the 620 species of fishes in Yunnan are listed.

Infection Status of Zoonotic Trematode Metacercariae in Fishes from Vientiane Municipality and Champasak Province in Lao PDR

PubMed Central

Eom, Keeseon S.; Park, Han-Sol; Lee, Dongmin; Sohn, Woon-Mok; Yong, Tai-Soon; Chai, Jong-Yil; Min, Duk-Young; Rim, Han-Jong; Insisiengmay, Bounnaloth; Phommasack, Bounlay

2015-01-01

The infection status of fishborne zoonotic trematode (FZT) metacercariae was investigated in fishes from 2 localities of Lao PDR. Total 157 freshwater fishes (17 species) were collected in local markets of Vientiane Municipality and Champasak Province in December 2010 and July 2011, and each fish was examined by the artificial digestion method. Total 6 species of FZT metacercariae, i.e., Opisthorchis viverrini, Haplorchis taichui, Haplorchis yokogawai, Haplorchis pumilio, Centrocestus formosanus, and Procerovum varium, were detected in fishes from Vientiane Municipality. The metacercariae of O. viverrini were detected in 50 (49.5%) out of 101 fishes (6 species), and their average number was 154 per fish infected. The remaining 5 species of heterophyid metacercariae were detected in 36.8%, 65.8%, 9.4%, 23.9%, and 5.1% fishes examined, and their average densities were 12, 1,038, 4, 15, and 13 per infected fish, respectively. In fishes from Champasak Province, 3 species of FZT metacercariae, i.e., O. viverrini, H. taichui, and H. yokogawai, were detected. Only 2 O. viverrini metacercariae were found in only 1 Barbonymus schwanefeldi. The metacercariae of H. taichui and H. yokogawai were detected in 60.0% and 50.0% of fishes examined, and their average densities were 47 and 28 per fish infected. By the present study, it has been confirmed that several species of FZT metacercariae are prevalent in fishes from Vientiane Municipality, with P. varium being a new member of FZT in Lao PDR. In comparison, FZT metacercariae are less prevalent in fishes from Champasak Province. PMID:26323843

COI (cytochrome oxidase-I) sequence based studies of Carangid fishes from Kakinada coast, India.

PubMed

Persis, M; Chandra Sekhar Reddy, A; Rao, L M; Khedkar, G D; Ravinder, K; Nasruddin, K

2009-09-01

Mitochondrial DNA, cytochrome oxidase-1 gene sequences were analyzed for species identification and phylogenetic relationship among the very high food value and commercially important Indian carangid fish species. Sequence analysis of COI gene very clearly indicated that all the 28 fish species fell into five distinct groups, which are genetically distant from each other and exhibited identical phylogenetic reservation. All the COI gene sequences from 28 fishes provide sufficient phylogenetic information and evolutionary relationship to distinguish the carangid species unambiguously. This study proves the utility of mtDNA COI gene sequence based approach in identifying fish species at a faster pace.

Species richness and patterns of invasion in plants, birds, and fishes in the United States

USGS Publications Warehouse

Stohlgren, Thomas J.; Barnett, David; Flather, Curtis; Fuller, Pamela L.; Peterjohn, Bruce G.; Kartesz, John; Master, Lawrence L.

2006-01-01

We quantified broad-scale patterns of species richness and species density (mean # species/km2) for native and non-indigenous plants, birds, and fishes in the continental USA and Hawaii. We hypothesized that the species density of native and non-indigenous taxa would generally decrease in northern latitudes and higher elevations following declines in potential evapotranspiration, mean temperature, and precipitation. County data on plants (n = 3004 counties) and birds (n=3074 counties), and drainage (6 HUC) data on fishes (n = 328 drainages) showed that the densities of native and non-indigenous species were strongly positively correlated for plant species (r = 0.86, P < 0.0001), bird species (r = 0.93, P<0.0001), and fish species (r = 0.41, P<0.0001). Multiple regression models showed that the densities of native plant and bird species could be strongly predicted (adj. R2 = 0.66 in both models) at county levels, but fish species densities were less predictable at drainage levels (adj. R2 = 0.31,P<0.0001). Similarly, non-indigenous plant and bird species densities were strongly predictable (adj. R2 = 0.84 and 0.91 respectively), but non-indigenous fish species density was less predictable (adj. R2 = 0.38). County level hotspots of native and non-indigenous plants, birds, and fishes were located in low elevation areas close to the coast with high precipitation and productivity (vegetation carbon). We show that (1) native species richness can be moderately well predicted with abiotic factors; (2) human populations have tended to settle in areas rich in native species; and (3) the richness and density of non-indigenous plant, bird, and fish species can be accurately predicted from biotic and abiotic factors largely because they are positively correlated to native species densities. We conclude that while humans facilitate the initial establishment, invasions of non-indigenous species, the spread and subsequent distributions of non-indigenous species may be controlled largely by environmental factors.

Comparative genome analysis of 52 fish species suggests differential associations of repetitive elements with their living aquatic environments.

PubMed

Yuan, Zihao; Liu, Shikai; Zhou, Tao; Tian, Changxu; Bao, Lisui; Dunham, Rex; Liu, Zhanjiang

2018-02-13

Repetitive elements make up significant proportions of genomes. However, their roles in evolution remain largely unknown. To provide insights into the roles of repetitive elements in fish genomes, we conducted a comparative analysis of repetitive elements of 52 fish species in 22 orders in relation to their living aquatic environments. The proportions of repetitive elements in various genomes were found to be positively correlated with genome sizes, with a few exceptions. More importantly, there appeared to be specific enrichment between some repetitive element categories with species habitat. Specifically, class II transposons appear to be more abundant in freshwater bony fish than in marine bony fish when phylogenetic relationship is not considered. In contrast, marine bony fish harbor more tandem repeats than freshwater species. In addition, class I transposons appear to be more abundant in primitive species such as cartilaginous fish and lamprey than in bony fish. The enriched association of specific categories of repetitive elements with fish habitats suggests the importance of repetitive elements in genome evolution and their potential roles in fish adaptation to their living environments. However, due to the restriction of the limited sequenced species, further analysis needs to be done to alleviate the phylogenetic biases.

Niches of dominant fish in the waters surrounding the Taishan Islands, China

NASA Astrophysics Data System (ADS)

Yang, Lu; Chen, Jie; Yang, Shengyun; Zhong, Huiqi; Ju, Peilong; Yang, Shunliang; Sun, Qinqin; Chen, Mingru

2016-07-01

An index of relative importance (IRI) was employed to screen for dominant fish in the waters surrounding the Taishan Islands, China, using data from four seasonal trawl surveys undertaken between 2012 and 2013. Niche breadth and niche overlap were measured using the Feinsinger and Morisita-Horn indices, respectively, and the characteristics and seasonal variations in the niches of dominant fish were assessed via non-metric multidimensional scaling (NMDS) and cluster analysis. A total of 80 fish species, including 16 dominant species, were recorded. Only Amblychaeturichthys hexanema was dominant in all seasons. According to niche breadth values and NMDS, the 16 dominant species were grouped into the following three types: (1) wide niche breadth species, including Cynoglossus macrolepidotus, A. hexanema, and Trypauchen vagina, among others; (2) medium niche breadth species, including Setipinna taty and Johnius belangerii; and (3) narrow niche breadth species, including Atrobucca nibe and Coilia mystus. Most species with a wider niche breadth were demersal fish with a lower swimming capability and even distribution. The niche breadth of migrating fish was narrower than that of settled fish. At a given spatial scale, fish with stronger swimming capabilities had a narrower niche breadth. Niche overlap, which is associated with niche specialization, ranged from 0.000 to 0.886 and had an annual mean value of 0.314. In summer and autumn, niche overlap was relatively high within species of the Sciaenidae family and within species of the Gobiidae in autumn. Differences in thermophily, feeding habits, food organism abundance/distribution and predator-prey relationships affected the niche overlap of fish in this area. Cluster analysis revealed that species with the narrowest niche breadth and lowest niche overlap values usually displayed lower aggregation and greater distribution differences compared with other species.

Fish population studies using parasites from the Southeastern Pacific Ocean: considering host population changes and species body size as sources of variability of parasite communities.

PubMed

George-Nascimento, Mario; Oliva, Marcelo

2015-01-01

Research using parasites in fish population studies in the South Eastern Pacific (SEP) is summarized. There are 27 such studies (snapshots mainly) in single host species sampled at different geographic localities and at somewhat similar times. They have been devoted mainly to economically important species, though others on coastal and intertidal fish or on less- or non-commercial species provide insights on scales of temporal and spatial variation of parasite infracommunities. Later, we assess whether the probability of harbouring parasites depends on the host species body size. Our results indicate that a stronger tool for fish population studies may be developed under regular (long term) scrutiny of parasite communities, especially of small fish host species, due to their larger variability in richness, abundance and total biomass, than in large fish species. Finally, it might also be necessary to consider the effects of fishing on parasite communities as well as the natural oscillations (coupled or not) of host and parasite populations.

Mayfly and fish species identification and sex determination in bleak (Alburnus alburnus) by MALDI-TOF mass spectrometry.

PubMed

Maasz, G; Takács, P; Boda, P; Varbiro, G; Pirger, Z

2017-12-01

Besides food quality control of fish or cephalopods, the novel mass spectrometry (MS) approaches could be effective and beneficial methods for the investigation of biodiversity in ecological research. Our aims were to verify the applicability of MALDI-TOF MS in the rapid identification of closely related species, and to further develop it for sex determination in phenotypically similar fish focusing on the low mass range. For MALDI-TOF MS spectra analysis, ClinProTools software was applied, but our observed classification was also confirmed by Self Organizing Map. For verifying the wide applicability of the method, brains from invertebrate and vertebrate species were used in order to detect the species related markers from two mayflies and eight fish as well as sex-related markers within bleak. Seven Ephemera larvae and sixty-one fish species related markers were observed and nineteen sex-related markers were identified in bleak. Similar patterns were observed between the individuals within one species. In contrast, there were markedly diverse patterns between the different species and sexes visualized by SOMs. Two different Ephemera species and male or female fish were identified with 100% accuracy. The various fish species were classified into 8 species with a high level of accuracy (96.2%). Based on MS data, dendrogram was generated from different fish species by using ClinProTools software. This MS-based dendrogram shows relatively high correspondence with the phylogenetic relationships of both the studied species and orders. In summary, MALDI-TOF MS provides a cheap, reliable, sensitive and fast identification tool for researchers in the case of closely related species using mass spectra acquired in a low mass range to define specific molecular profiles. Moreover, we presented evidence for the first time for determination of sex within one fish species by using this method. We conclude that it is a powerful tool that can revolutionize ecological and environmental research. Copyright © 2017 Elsevier B.V. All rights reserved.

Infections of nervous necrosis virus in wild and cage-reared marine fish from South China Sea with unexpected wide host ranges.

PubMed

Liu, X D; Huang, J N; Weng, S P; Hu, X Q; Chen, W J; Qin, Z D; Dong, X X; Liu, X L; Zhou, Y; Asim, M; Wang, W M; He, J G; Lin, L

2015-06-01

The concerns about the impact of the nervous necrosis virus (NNV) infections in wild fish have been raised. This paper presents the results of quarterly surveys of NNV in wild and cage-reared marine fish from South China Sea. Samples of 892 wild fish belonging to 69 species and 381 cage-reared fish belonging to 11 species were collected and were detected by seminested PCR and nested PCR. In the case of seminested PCR, the positive signal was detected in 3.0% and 3.1% samples of wild and cage-reared fish, respectively. However, by nested RT-PCR, the positive signal was observed in 42.3% and 63.0% samples of wild and cage-reared fish, respectively. If the fish species were considered, the positive signal was detected in 21.7% and 72.7% species of wild and cage-reared fish by seminested PCR assay, respectively. However, by nested RT-PCR, the positive signal was observed in 65.2% and 100% species of wild and cage-reared fish, respectively. The nucleotide sequences of the nested PCR products were determined. Phylogenetic tree showed that all the obtained viral isolates belonged to the red-spotted grouper nervous necrosis virus (RGNNV) genotype. Thirty-five species of the marine fish were the new hosts of NNV. © 2014 John Wiley & Sons Ltd.

Impact of estuary barrage construction on fish assemblages in the lower part of a river and the role of fishways as a passage

NASA Astrophysics Data System (ADS)

Yoon, Ju-Duk; Kim, Jeong-Hui; Park, Sang-Hyeon; Kim, Eve; Jang, Min-Ho

2017-03-01

The construction of an estuary barrage, an instream structure in the lower reaches of a river, causes significant physical changes in water flow patterns and river morphology, and results in altered environmental conditions. Here, we examined the impact of the Geum River estuary barrage, completed in 1990, on fish assemblages by using a literature search and fresh surveys of fishways in the barrage. We found that fish assemblages upstream and downstream of the barrage were altered following its completion. After construction, more species were found in the freshwater area, with a particularly great increase in freshwater species. Conversely, estuarine and marine species were only consistently caught in the downstream salt-water area, although the number of species increased. In total, 15,829 fish from 47 species and 20 families were identified at the three types (pool and weir, rubble type, and boat passage) of fishways in the barrage. The dominant species were Chelon haematocheilus, an estuarine species, Coilia nasus, a diadromous species, and Erythroculter erythropterus, a freshwater species. The mean total length of fish (101.9 ± 76.0 mm) in the boat passage fishway was approximately 100 mm lesser than those in the pool and weir (207.2 ± 112.8 mm) and rubble type (205.8 ± 112.7 mm) fishways. The boat passage fishway was the most efficient for fish movements. The current fishway system is not sufficient for fish migration, and thus additional ways are required to improve the system such as the boat passage. Few estuarine or diadromous species were found in both freshwater and salt-water areas, but freshwater fishes that accidently moved to salt-water area actively used fishways. Therefore, fishway management in the Geum River estuary barrage has to focus on freshwater fish; however, this may need to change to a focus on migratory fishes depending on ecological life cycles of migratory fish.

[Which factors determine the altitudinal distribution of tropical Andean riverine fishes]?

PubMed

De La Barra, Evans; Zubieta, José; Aguilera, Gastón; Maldonado, Mabel; Pouilly, Marc; Oberdorff, Thierry

2016-03-01

Altitudinal gradients represent an appropriate system to assess whether there is a relationship between richness patterns, environmental variables, and the ecological processes that determine the species type and number inhabiting a given area. In mountain streams freshwater fishes, the most prevalent relationship is a monotonic decrease in species richness with elevation. The objective of this study was to evaluate four hypotheses that can explain the negative relationship between local fish species richness and altitude, 1) the hypothesis of decreasing energy availability, 2) the hypothesis of increasing climate severity, 3) the hypothesis of habitat diversity, and 4) the hypothesis of isolation by physical severity of the environment. Fish and macro-invertebrates were collected following standard methods from 83 sites (between 200-4 000 meters) of two river basins in the Bolivian Amazon. The first hypothesis was tested by analyzing relationships between the density of macro-invertebrates, the richness of invertivorous fish species and altitude; while the second and third hypotheses were assessed by a multiple regression analysis (GLM) between fish species richness and several local and regional factors. Besides, assemblage dissimilarity between sites along the altitudinal gradient was analyzed using βsim and βness indices. Fish richness decreases linearly with increasing altitude. The density of macro-invertebrates tends to increase at higher altitudes, contrary to invertivorous fish species richness, suggesting that energy availability is not a limiting factor for fish species colonization. The GLM explained 86 % of the variation in fish species richness, with a significant contribution of water temperature, maximum slope in the river mainstem, and stream width. There is a higher species turnover (βsim) between sites at low elevation. Inversely, βness shows higher values in the upper parts, corresponding to change in assemblages mainly due to species loss. Taken together, these results suggest that climatic and physical severities create strong barriers to colonization, further explaining the decrease in fish richness along the altitudinal gradient.

Red List of lampreys and marine fishes of the Wadden Sea

NASA Astrophysics Data System (ADS)

Berg, S.; Krog, C.; Muus, B.; Nielsen, J.; Fricke, R.; Berghahn, R.; Neudecker, Th.; Wolff, W. J.

1996-10-01

In the Wadden Sea areas of Denmark, Germany and The Netherlands, a total of 162 fish and lamprey species is known. 72 of these species are migrants entering the area occasionally; the total number of resident species in the Wadden Sea area is 90. In the Wadden Sea, in total, 20 species of fish and lamprey species are threatened in at least one subregion. Of these, 19 species are threatened in the entire area and are therefore placed on the trilateral Red List. 2 species of the listed fish and lamprey species are (probably) extinct in the entire Wadden Sea area. The status of 5 species of fish and lamprey species is critical, 5 species are (probably) endangered, the status of 6 is vulnerable and of 1 species susceptible. For about 16 rare species which may also be threatened, data were not sufficient to estimate past and present population sizes. The contributors to the list would like to encourage researchers to intensify work on the ecology and the present population sizes of these rare Wadden Sea species (see Fricke et al., 1995).

[Trophic webs of reef fishes in northwestern Cuba. I. Stomach contents].

PubMed

Hernández, Ivet; Aguilar, Consuelo; González Sanón, Gaspar

2008-06-01

Trophic webs of reef fishes in northwestern Cuba. I. Stomach contents. Studies on the reef fishes of Cuba are not rare, but most have two basic limitations: small sample sizes and exclusion of small species. Our study sampled more species and larger samples in the sublitoral region of Havana city (23 degrees 7.587' N, 82 degrees 25.793' W), 2-18 m deep. We collected fish weekly from October 2004 through February 2006 with traps and harpoon. Overfishing has modified the fish communities. We used the relative importance index to describe the diets of carnivore and omnivore species, and a modification of the relative abundance method for the herbivores and sponge-eating species. The main food items are benthonic crustaceans (crabs, shrimp, copepods) and bony fish (mainly demersal species). Most species are eurifagous and thus, less affected by anthropic disturbance than specialist feeders.

Can Fish Morphological Characteristics be Used to Re-design Hydroelectric Turbines?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cada, G. F.; Richmond, Marshall C.

2011-07-19

Safe fish passage affects not only migratory species, but also populations of resident fish by altering biomass, biodiversity, and gene flow. Consequently, it is important to estimate turbine passage survival of a wide range of susceptible fish. Although fish-friendly turbines show promise for reducing turbine passage mortality, experimental data on their beneficial effects are limited to only a few species, mainly salmon and trout. For thousands of untested species and sizes of fish, the particular causes of turbine passage mortality and the benefits of fish-friendly turbine designs remain unknown. It is not feasible to measure the turbine-passage survival of everymore » species of fish in every hydroelectric turbine design. We are attempting to predict fish mortality based on an improved understanding of turbine-passage stresses (pressure, shear stress, turbulence, strike) and information about the morphological, behavioral, and physiological characteristics of different fish taxa that make them susceptible to the stresses. Computational fluid dynamics and blade strike models of the turbine environment are re-examined in light of laboratory and field studies of fish passage effects. Comparisons of model-predicted stresses to measured injuries and mortalities will help identify fish survival thresholds and the aspects of turbines that are most in need of re-design. The coupled model and fish morphology evaluations will enable us to make predictions of turbine-passage survival among untested fish species, for both conventional and advanced turbines, and to guide the design of hydroelectric turbines to improve fish passage survival.« less

Clove oil induces anaesthesia and blunts muscle contraction power in three Amazon fish species.

PubMed

Fujimoto, Rodrigo Yudi; Pereira, Débora Martins; Silva, Jessica Cristina Souza; de Oliveira, Laís Cássia Araújo; Inoue, Luis Antonio Kioshi Aoki; Hamoy, Moisés; de Mello, Vanessa Jóia; Torres, Marcelo Ferreira; Barbas, Luis André Luz

2018-02-01

Clove oil is used as an anaesthetic for many species of fish worldwide; however, relatively few studies have assessed its effectiveness on Amazon fish species and no compelling evidence has ever been reported on the relaxant properties of this oil for skeletal muscle of fish. Thus, the objective of this study was to evaluate the latencies to deep anaesthesia and recovery, along with the myorelaxant effect of clove oil on three Amazon fish species: cardinal tetra, Paracheirodon axelrodi, banded cichlid, Heros severus and angelfish, Pterophyllum scalare, submitted to short-term anaesthetic baths. Fish were assayed in three groups of 60 fish each and individually anaesthetized in a completely randomized design with six clove oil concentrations using 10 fish/species/concentration. Electromyographic recordings from dorsal muscle were performed during stages of induction and recovery in which nine fish/species/stage were used. Deep anaesthesia was attained for all concentrations tested, and no mortalities were observed throughout the experiments and after a 48-h observation period. Concentration of 90 μL L -1 and above promoted fast deep anaesthesia (< 3 min) and calm recovery in angelfish and cardinal tetra, whereas the concentration of 60 μL L -1 sufficed to quickly anaesthetize banded cichlid. Times to full recovery were not significantly contrasting among species and occurred within appropriate time threshold (< 5 min). Clove oil exerted a conspicuous depression of muscle contraction power, and therefore can be effectively used as a muscle relaxant agent for P. scalare, P. axelrodi, H. severus and potentially, for other fish species.

77 FR 34349 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-11

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Department of Fish and Wildlife (ODFW) pursuant to the protective regulations promulgated for Pacific salmon... hatchery fish to support fishing opportunities while minimizing potential risks to natural-origin spring...

Development of DNA-based Identification methods to track the species composition of fish larvae within nearshore areas of the Great Lakes

EPA Science Inventory

The ability to track the identity and abundance of larval fish, which are ubiquitous during spawning season, may lead to a greater understanding of fish species distributions in Great Lakes nearshore areas including early-detection of invasive fish species before they become esta...

Spatial variation in fish assemblages across a beaver-influenced successional landscape

USGS Publications Warehouse

Schlosser, I.J.; Kallemeyn, L.W.

2000-01-01

Beavers are increasingly viewed as “ecological engineers,” having broad effects on physical, chemical, and biological attributes of north-temperate landscapes. We examine the influence of both local successional processes associated with beaver activity and regional geomorphic boundaries on spatial variation in fish assemblages along the Kabetogama Peninsula in Voyageurs National Park, northern Minnesota, USA. Fish abundance and species richness exhibited considerable variation among drainages along the peninsula. Geological barriers to fish dispersal at outlets of some drainages has reduced fish abundance and species richness. Fish abundance and species richness also varied within drainages among local environments associated with beaver pond succession. Fish abundance was higher in upland ponds than in lowland ponds, collapsed ponds, or streams, whereas species richness was highest in collapsed ponds and streams. Cluster analyses based on fish abundance at sites classified according to successional environment indicated that four species (northern redbelly dace, Phoxinus eos; brook stickleback, Culaea inconstans; finescale dace, P. neogaeus; and fathead minnow, Pimephales promelas), were predominant in all successional environments. Several less abundant species were added in collapsed ponds and streams, with smaller size classes of large lake species (e.g., black crappie, Pomoxis nigromaculatus; smallmouth bass, Micropertus dolomieui; yellow perch, Perca flavescens; and burbot, Lota lota) being a component of these less abundant species. The addition of smaller size classes of large lake species indicates that dispersal of early life-history stages from Kabetogama Lake played a role in determining the species richness and composition of less abundant species in successional environments on the peninsula. Furthermore, collapsed-pond and stream environments closer to Kabetogama Lake had higher species richness than similar successional sites located farther from the lake. Cluster analyses based on fish abundance at sites classified according to drainage indicated that species composition among drainages was influenced both by the presence or absence of geological barriers to fish dispersal and the nonrandom distribution of collapsed ponds and streams. Based on these results, we present a hierarchical conceptual model suggesting how geomorphic boundaries and beaver pond succession interact to influence fish assemblage attributes. The presence of a productive and diverse fish assemblage in headwater streams of north-temperate areas requires the entire spatial and temporal mosaic of successional habitats associated with beaver activity, including those due to the creation and abandonment of beaver ponds. The ultimate impact of the local successional mosaic on fishes, however, will be strongly influenced by the regional geomorphic context in which the mosaic occurs.

A checklist of ciliate parasites (Ciliophora) of fishes from Mexico.

PubMed

Aguilar-Aguilar, Rogelio; Islas-Ortega, Alma Gabriela

2015-10-02

A database with all available published accounts of the ciliate parasite species of Mexican fishes was assembled. This information, along with records derived from own recent research, allow generating a checklist containing all the records, which is a necessary first step to address future questions in the areas of ecology, evolutionary biology and biogeography of these host-parasite associations. The checklist is presented as a parasite-host list, and a host-parasite list. The checklist contains 30 nominal species, from 9 genera and 8 families of ciliate parasites. Most of the primary records were done for exotic fish species, artificially introduced to Mexico for aquaculture purposes; however, recent works have been conducted in diverse species of native fishes. Excepting one, all the ciliate species listed here have been previously recorded for diverse fish species from different localities around the world. Based on the amount of information contained in this checklist, much more effort is necessary to accurately know the diversity of species of this type of parasites in fish fauna of Mexico.

Bioaccumulation of trace mercury in trophic levels of benthic, benthopelagic, pelagic fish species, and sea birds from Arvand River, Iran.

PubMed

Hosseini, Mehdi; Nabavi, Seyed Mohammad Bagher; Parsa, Yaghob

2013-12-01

In this study, concentration of mercury was determined in the trophic levels of benthic, benthopelagic, pelagic fish species, and river birds from Arvand River, located in the Khuzestan province in the lowlands of southwestern Iran at the head of the Persian Gulf. The order of mercury concentrations in tissues of the fish species was as follows: liver>gill>muscle and in tissues of the kingfisher species was as follows: feather>liver>kidney>muscle. Therefore, liver in fish and feather in kingfisher exhibited higher mercury concentration than the other tissues. There was a positive correlation between mercury concentrations in fish and kingfisher species with size of its food items. We expected to see higher mercury levels in tissues of female species because they are larger and can eat larger food items. The results of this study show that the highest mean mercury level were found in the kingfisher (Anas crecca), followed by benthic (Epinephelus diacanthus), benthopelagic (Chanos chanos), and pelagic fish (Strongylura strongylura). Mean value of mercury in fish species, S. strongylura were (0.61 μg g(-1) dry weight), C. chanos (0.45 μg g(-1) dry weight), E. diacanthus (0.87 μg g(-1) dry weight), and in kingfisher species A. crecca was (2.64 μg g(-1) dry weight). Significant correlation between mercury concentration in fish and kingfisher may be related to high variability of mercury in the fish.

Zur Ökophysiologie, Sexualität und Populationsgenetik litoraler Gammaridea — ein Überblick

NASA Astrophysics Data System (ADS)

Bulnheim, H.-P.

1991-09-01

Comparative investigations on the physiological capacities in the euryhaline amphipods Gammarus locusta, G. oceanicus, G. salinus, G. zaddachi and G. duebeni were reviewed. In order to assess the adaptations of these species to the abiotic conditions of their environment, the following criteria were examined: oxygen consumption in relation to ambient salinity and temperature levels, respiratory responses following osmotic stress, resistance capacities to oxygen deficiency, resistance to aerial exposure and the simultaneous presence of hydrogen sulphide. Covering the range from marine to typically brackish-water inhabitants, the 5 species show adaptive responses in the above-mentioned order. Respiration is less intensely modified by external factors, and oxygen consumption decreases. Accompanied by faster rates of acclimation to new steady states of performance, resistance capacities increase. The significance of the findings obtained is discussed in relation to the environmental requirements of the amphipods considered. Based on breeding experiments, the sex-determining systems reported thus far in Gammarus species are outlined. As demonstrated in G. duebeni, a more or less pronounced influence of external factors such as photoperiod may become effective. A preponderance of males was noted when offspring were raised under long-day photoperiods, whereas females prevailed under short-day conditions. In terms of the critical daylength, the light per day was estimated as being between 13 and 14 h (Elbe estuary population). Feminizing microporidians ( Octosporea effeminans, Thelohania herediteria), which are transovarially transmitted, can interfere with the system of sex determination and sex differentiation of the host. As reflected in various G. duebeni populations, they cause a maternally transferred sex-ratio condition by the production of all-female broods, thereby mimicking extrachromosomal inheritance. An increase of the salinity level to 25 30‰ results in a disappearance of O. effeminans. In both microsporidians, long exposure to low temperatures (≤4°C) produces eggs which are not all parasitized. Furthermore, intersexuality can be induced by changing environmental factors. Microsporidian species have no influence on sex differentiation in G. duebeni celticus, G. salinus, G. locusta and G. pulex. Patterns of relative electrophoretic mobilities of proteins and the distribution of allele frequencies at polymorphic gene loci can be utilized for species diagnosis and for the evaluation of the relationships between different taxa, particularly at and below the species level. As exemplified by studies on several gammarids from marine, brackish and freshwater environments, inter- and infraspecific gene-enzyme variation is described. Electrophoretic investigations on natural populations of the euryhaline amphipods G. zaddachi, G. salinus, G. tigrinus and others from different geographic areas provided evidence of considerable biochemical genetic variation. In Talitrus saltator- and Talorchestia deshayesii-populations the extent of variability based on micro-and macrogeographic aspects is illustrated. The large-scale genetic divergence is demonstrated by comparison of samples obtained from the Baltic, North, Atlantic and northern Mediterranean Seas.

Detection and genetic analysis of aquabirnaviruses in subclinically infected aquarium fish.

PubMed

Shin, Sang Phil; Gomez, Dennis Kaw; Kim, Ji Hyung; Choresca, Casiano Hermorpia; Han, Jee Eun; Jun, Jin Woo; Park, Se Chang

2011-03-01

Aquabirnaviruses (ABVs) cause serious diseases in a variety of fish species used worldwide in aquaculture and have been isolated from a variety of healthy fish and shellfish species. The type species of ABV is Infectious pancreatic necrosis virus (IPNV), which is the causative agent of a highly contagious disease in juvenile salmonid fish. Marine birnaviruses (MABVs) have been isolated from various marine fish and shellfish. In Korea, ABV infection has been identified in several fish and shellfish. The current study presents sequence data from nested polymerase chain reaction products of 3 ABV strains obtained from different species of asymptomatic aquarium fish collected from a private commercial aquarium in Korea. Phylogenetic analysis of these strains, based on the partial nucleotide sequence of the VP2/NS junction, placed them within the genogroup VII (95-99% bootstrap confidence), which also contains MABV. The subclinically infected fish may be a source of MABV infection for other susceptible fish species inside the aquarium and potentially represent a serious challenge for the management of MABV infections. Additionally, the presence of MABV in these subclinically infected aquarium fish imported from other countries indicates that there is a need for the establishment of appropriate quarantine practices.

The distribution of mitochondria-rich cells in the gills of air-breathing fishes.

PubMed

Lin, Hui-Chen; Sung, Wen-Ting

2003-01-01

Respiration and ion regulation are the two principal functions of teleostean gills. Mainly found in the gill filaments of fish, mitochondria-rich cells (MRCs) proliferate to increase the ionoregulatory capacity of the gill in response to osmotic challenges. Gill lamellae consist mostly of pavement cells, which are the major site of gas exchange. Although lamellar MRCs have been reported in some fish species, there has been little discussion of which fish species are likely to have lamellar MRCs. In this study, we first compared the number of filament and lamellar MRCs in air-breathing and non-air-breathing fish species acclimated to freshwater and 5 g NaCl L(-1) conditions. An increase in filament MRCs was found in both air-breathing and non-air-breathing fish acclimated to freshwater. Lamellar MRCs were found only in air-breathing species, but the number of lamellar MRCs did not change significantly with water conditions, except in Periophthalmus cantonensis. Next, we surveyed the distribution of MRCs in the gills of 66 fish species (including 29 species from the previous literature) from 12 orders, 28 families, and 56 genera. Our hypothesis that lamellar MRCs are more likely to be found in air-breathing fishes was supported by a significant association between the presence of lamellar MRCs and the mode of breathing at three levels of systematic categories (species, genus, and family). Based on this integrative view of the multiple functions of fish gills, we should reexamine the role of MRCs in freshwater fish.

Neotropical fish-fruit interactions: eco-evolutionary dynamics and conservation.

PubMed

Correa, Sandra Bibiana; Costa-Pereira, Raul; Fleming, Theodore; Goulding, Michael; Anderson, Jill T

2015-11-01

Frugivorous fish play a prominent role in seed dispersal and reproductive dynamics of plant communities in riparian and floodplain habitats of tropical regions worldwide. In Neotropical wetlands, many plant species have fleshy fruits and synchronize their fruiting with the flood season, when fruit-eating fish forage in forest and savannahs for periods of up to 7 months. We conducted a comprehensive analysis to examine the evolutionary origin of fish-fruit interactions, describe fruit traits associated with seed dispersal and seed predation, and assess the influence of fish size on the effectiveness of seed dispersal by fish (ichthyochory). To date, 62 studies have documented 566 species of fruits and seeds from 82 plant families in the diets of 69 Neotropical fish species. Fish interactions with flowering plants are likely to be as old as 70 million years in the Neotropics, pre-dating most modern bird-fruit and mammal-fruit interactions, and contributing to long-distance seed dispersal and possibly the radiation of early angiosperms. Ichthyochory occurs across the angiosperm phylogeny, and is more frequent among advanced eudicots. Numerous fish species are capable of dispersing small seeds, but only a limited number of species can disperse large seeds. The size of dispersed seeds and the probability of seed dispersal both increase with fish size. Large-bodied species are the most effective seed dispersal agents and remain the primary target of fishing activities in the Neotropics. Thus, conservation efforts should focus on these species to ensure continuity of plant recruitment dynamics and maintenance of plant diversity in riparian and floodplain ecosystems. © 2015 Cambridge Philosophical Society.

Reproduction and community structure of fish from winter catch sites from industrial shrimp bycatch from the northeast and southeast Mexican Pacific.

PubMed

Tirado-Ibarra, Jorge de Jesus; Loya-Rodriguez, Mariany; Morales-Arevalo, Jose Carlos; Muñoz-Garcia, Isabel Rosario; Martinez-Perez, Francisco; Ramirez-Perez, Jorge Saul; Jimenez-Gutierrez, Laura Rebeca

2018-01-01

The shrimp fishery is one of the most important fisheries in the world, although the low selectivity from trawling nets has led to the capture of a large number of non-target species. Shrimp-bycatch species include a large number of fish and invertebrate species, of which fish species are the most abundant. The present study aims to determine the community structure as well as the average sizes at first maturity of the fish species from shrimp-bycatch caught from industrial fisheries in the Mexican Pacific from Sinaloa to Guerrero, from January to March 2015. The shrimp-bycatch fish diversity value was found to be 2.22. A total of 37 species of finfish were found, of which five were considered rare. The fish species with the highest Importance Value Index (IVI) levels were Pseudupeneus grandisquamis , Paralichthys woolmani , Lutjanus peru and Diapterus peruvianus . The average size at first maturity was calculated for all species. Of the analysed organisms, 90% were in the juvenile stage, including species with riverine and artisanal fisheries. The present study demonstrates the risk within marine populations to different non-target species due to the poor selectivity of shrimp trawls.

Going with the flow: using species-discharge relationships to forecast losses in fish biodiversity.

PubMed

Xenopoulos, Marguerite A; Lodge, David M

2006-08-01

In response to the scarcity of tools to make quantitative forecasts of the loss of aquatic species from anthropogenic effects, we present a statistical model that relates fish species richness to river discharge. Fish richness increases logarithmically with discharge, an index of habitat space, similar to a species-area curve in terrestrial systems. We apply the species-discharge model as a forecasting tool to build scenarios of changes in riverine fish richness from climate change, water consumption, and other anthropogenic drivers that reduce river discharge. Using hypothetical reductions in discharges (of magnitudes that have been observed in other rivers), we predict that reductions of 20-90% in discharge would result in losses of 2-38% of the fish species in two biogeographical regions in the United States (Lower Ohio-Upper Mississippi and Southeastern). Additional data on the occurrence of specific species relative to specific discharge regimes suggests that fishes found exclusively in high discharge environments (e.g., Shovelnose sturgeon) would be most vulnerable to reductions in discharge. Lag times in species extinctions after discharge reduction provide a window of opportunity for conservation efforts. Applications of the species-discharge model can help prioritize such management efforts among species and rivers.

Linking adults and immatures of South African marine fishes.

PubMed

Steinke, Dirk; Connell, Allan D; Hebert, Paul D N

2016-11-01

The early life-history stages of fishes are poorly known, impeding acquisition of the identifications needed to monitor larval recruitment and year-class strength. A comprehensive database of COI sequences, linked to authoritatively identified voucher specimens, promises to change this situation, representing a significant advance for fisheries science. Barcode records were obtained from 2526 early larvae and pelagic eggs of fishes collected on the inshore shelf within 5 km of the KwaZulu-Natal coast, about 50 km south of Durban, South Africa. Barcodes were also obtained from 3215 adults, representing 946 South African fish species. Using the COI reference library on BOLD based on adults, 89% of the immature fishes could be identified to a species level; they represented 450 species. Most of the uncertain sequences could be assigned to a genus, family, or order; only 92 specimens (4%) were unassigned. Accumulation curves based on inference of phylogenetic diversity indicate near-completeness of the collecting effort. The entire set of adult and larval fishes included 1006 species, representing 43% of all fish species known from South African waters. However, this total included 189 species not previously recorded from this region. The fact that almost 90% of the immatures gained a species identification demonstrates the power and completeness of the DNA barcode reference library for fishes generated during the 10 years of FishBOL.

Cryopreservation of Fish Sperm

NASA Astrophysics Data System (ADS)

Kurokura, Hisashi

Present status of research activities in cryopreservation of fish gamete in aquaculture field was introduced. More than 59 fish species have been reported in the research histories and nearly half of them were studied during recent 10 years. This means that the research activities are increasing, though commercial profit have not obtained yet. Fish species of which sperm can successfully cryopreserved is still limited comparing to numerous species in telost. One of the major obstacle for improvement of the technique is existence of wide specie specific variance in the freezing tolerance of fish sperm. The varianc can possibly be explaind thorugh the informations obtained by the studies in comparative spermatology, which is recently activated field in fish biology.

The differentiation of common species in a coral-reef fish assemblage for recreational scuba diving.

PubMed

Chen, Tsen-Chien; Ho, Cheng-Tze; Jan, Rong-Quen

2016-01-01

Recreational scuba diving is a popular activity of the coral reef tourism industry. In practice, local diving centers recommend interesting sites to help visiting divers make their plans. Fish are among the major attractions, but they need to be listed with care because the temporal occurrence of a fish species is difficult to predict. To address this issue, we propose methods to categorize each fish species based on its long-term occurrence and likelihood of being seen. We assume that there are K categories of occurrence of a fish assemblage and propose two methods [an arithmetic-mean method (AM) and a geometric-mean method (GM)] to define the range of species in each category. Experiments based on long term datasets collected at three underwater stations (each having 51-53 surveys and totals of 262-284 fish species) on coral reefs in southern Taiwan showed that when K = 4 (rare, occasional, frequent and common categories), 11-14 species were concurrently assigned to the common category by AM for data sets based on surveys 10, 15, 20, 25, 30, 35, 40, 45, or 51-53 in contrast to the 18-26 species assigned as common by GM. If a similarity index of 0.7 (compared to the total pool of fish species) was the minimum threshold for diver satisfaction, then 20-25 surveys provide sufficient data for listing the common species at a given dive spot. Common fish species, are the most temporally stable, and thus are more appropriate for attracting divers. These can be effectively differentiated by either AM or GM with at least 25 surveys. We suggest regular updating of each fish's category through periodic surveys to assure the accuracy of information at a particular dive spot.

Experimental evaluation of diversity-productivity relationships in a coral reef fish assemblage.

PubMed

Messmer, Vanessa; Blowes, Shane A; Jones, Geoffrey P; Munday, Philip L

2014-09-01

The global decline in biodiversity is causing increasing concern about the effects of biodiversity loss on ecosystem services such as productivity. Biodiversity has been hypothesised to be important in maintaining productivity of biological assemblages because niche complementarity and facilitation among the constituent species can result in more efficient use of resources. However, these conclusions are primarily based on studies with plant communities, and the relationship between diversity and productivity at higher trophic levels is largely unknown, especially in the marine environment. Here, we used a manipulative field experiment to test the effects of species richness and species identity on biomass accumulation in coral reef fish assemblages at Lizard Island. Small patch reefs were stocked with a total of 30 juveniles belonging to three planktivorous damselfish (genus Pomacentrus) according to three different levels of fish species richness (one, two and three species) and seven different combinations of fish species. Species richness had no effect on the relative growth in this assemblage after 18 days, but relative growth differed among individual fish species and the different combinations of species. Patterns of increase in biomass were best explained by species-specific differences and variable effects of intra- and interspecific competition on growth. These results suggest that niche complementarity and facilitation are not the most influential drivers of total productivity within this guild of planktivorous fishes. Total productivity may be resilient to declining reef fish biodiversity, but this will depend on which species are lost and on the life-history traits of remaining species.

78 FR 74116 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-10

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... plans and request for comment. SUMMARY: Notice is hereby given that the Oregon Department of Fish and... River and Columbia River basins by providing hatchery fish to support fishing opportunities while...

77 FR 27188 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-09

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... plans and request for comment SUMMARY: Notice is hereby given that the Oregon Department of Fish and... River and Columbia River basins by providing hatchery fish to support fishing opportunities while...

Monitoring fish distributions along electrofishing segments

USGS Publications Warehouse

Miranda, Leandro E.

2014-01-01

Electrofishing is widely used to monitor fish species composition and relative abundance in streams and lakes. According to standard protocols, multiple segments are selected in a body of water to monitor population relative abundance as the ratio of total catch to total sampling effort. The standard protocol provides an assessment of fish distribution at a macrohabitat scale among segments, but not within segments. An ancillary protocol was developed for assessing fish distribution at a finer scale within electrofishing segments. The ancillary protocol was used to estimate spacing, dispersion, and association of two species along shore segments in two local reservoirs. The added information provided by the ancillary protocol may be useful for assessing fish distribution relative to fish of the same species, to fish of different species, and to environmental or habitat characteristics.

Biofluorescence as a survey tool for cryptic marine species.

PubMed

De Brauwer, Maarten; Hobbs, Jean-Paul A; Ambo-Rappe, Rohani; Jompa, Jamaluddin; Harvey, Euan S; McIlwain, Jennifer L

2017-10-06

As ecosystems come under increasing anthropogenic pressure, rare species face the highest risk of extinction. Paradoxically, data necessary to evaluate the conservation status of rare species are often lacking because of the challenges of detecting species with low abundance. One group of fishes subject to this undersampling bias are those with cryptic body patterns. Twenty-one percent of cryptic fish species assessed for their extinction risk (International Union for Conservation of Nature [IUCN]) are data deficient. We developed a nondestructive method for surveying cryptically patterned marine fishes based on the presence of biofluorescence (underwater biofluorescence census, UBC). Blue LED torches were used to investigate how widespread biofluorescence was in cryptic reef fishes in the Coral Triangle region. The effectiveness of UBC to generate abundance data was tested on a data-deficient pygmy seahorse species (Hippocampus bargibanti) and compared with data obtained from standard underwater visual census (UVC) surveys. We recorded 95 reef fish species displaying biofluorescence, 73 of which had not been previously described as biofluorescent. Of those fish with cryptic patterns, 87% were biofluorescent compared with 9% for noncryptic fishes. The probability of species displaying biofluorescence was 70.9 times greater for cryptic species than for noncryptic species. Almost twice the number of H. bargibanti was counted using the UBC compared with UVC. For 2 triplefin species (Ucla xenogrammus, Enneapterygius tutuilae), the abundance detected with UBC was triple that detected with UVC. The UBC method was effective at finding cryptic species that would otherwise be difficult to detect and thus will reduce interobserver variability inherent to UVC surveys. Biofluorescence is ubiquitous in cryptic fishes, making this method applicable across a wide range of species. Data collected using UBC could be used with multiple IUCN criteria to assess the extinction risk of cryptic species. Adopting this technique will enhance researchers' ability to survey cryptic species and facilitate management and conservation of cryptic marine species. © 2017 Society for Conservation Biology.

Spawning and nursery habitats of neotropical fish species in the tributaries of a regulated river

USGS Publications Warehouse

Makrakis, Maristela Cavicchioli; da Silva, Patrícia S.; Makrakis, Sergio; de Lima, Ariane F.; de Assumpção, Lucileine; de Paula, Salete; Miranda, Leandro E.; Dias, João Henrique Pinheiro

2012-01-01

This chapter provides information on ontogenetic patterns of neotropical fish species distribution in tributaries (Verde, Pardo, Anhanduí, and Aguapeí rivers) of the Porto Primavera Reservoir, in the heavily dammed Paraná River, Brazil, identifying key spawning and nursery habitats. Samplings were conducted monthly in the main channel of rivers and in marginal lagoons from October through March during three consecutive spawning seasons in 2007-2010. Most species spawn in December especially in Verde River. Main river channels are spawning habitats and marginal lagoons are nursery areas for most fish, mainly for migratory species. The tributaries have high diversity of larvae species: a total of 56 taxa representing 21 families, dominated by Characidae. Sedentary species without parental care are more abundant (45.7%), and many long-distance migratory fish species are present (17.4%). Migrators included Prochilodus lineatus, Rhaphiodon vulpinus, Hemisorubim platyrhynchos, Pimelodus maculatus, Pseudoplatystoma corruscans, Sorubim lima, two threatened migratory species: Salminus brasiliensis and Zungaro jahu, and one endangered migratory species: Brycon orbignyanus. Most of these migratory species are vital to commercial and recreational fishing, and their stocks have decreased drastically in the last decades, attributed to habitat alteration, especially impoundments. The fish ladder at Porto Primavera Dam appears to be playing an important role in re-establishing longitudinal connectivity among critical habitats, allowing ascent to migratory fish species, and thus access to upstream reaches and tributaries. Establishment of Permanent Conservation Units in tributaries can help preserve habitats identified as essential spawning and nursery areas, and can be key to the maintenance and conservation of the fish species in the Paraná River basin.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cada, Glenn F; Bevelhimer, Mark S

The development of hydrokinetic (HK) energy projects is under consideration at over 150 sites in large rivers in the United States, including the Mississippi, Ohio, Tennessee, and Atchafalaya Rivers. These waterbodies support numerous fish species that might interact with the HK projects in a variety of ways, e.g., by attraction to or avoidance of project structures. Although many fish species inhabit these rivers (about 172 species in the Mississippi River alone), not all of them will encounter the HK projects. Some species prefer low-velocity, backwater habitats rather than the high-velocity, main channel areas that would be the best sites formore » HK. Other, riverbank-oriented species are weak swimmers or too small to inhabit the main channel for significant periods of time. Some larger, main channel fish species are not known to be attracted to structures. Based on a consideration of habitat preferences, size/swim speed, and behavior, fish species that are most likely to be attracted to HK structures in the main channel include carps, suckers, catfish, white bass, striped bass, smallmouth bass, spotted bass, and sauger. Proper siting of the project in order to avoid sensitive fish populations, backwater and fish nursery habitat areas, and fish migration corridors will likely minimize concerns about fish attraction to or avoidance of HK structures.« less

The fish diversity in the upper reaches of the Salween River, Nujiang River, revealed by DNA barcoding.

PubMed

Chen, Weitao; Ma, Xiuhui; Shen, Yanjun; Mao, Yuntao; He, Shunping

2015-11-30

Nujiang River (NR), an essential component of the biodiversity hotspot of the Mountains of Southwest China, possesses a characteristic fish fauna and contains endemic species. Although previous studies on fish diversity in the NR have primarily consisted of listings of the fish species observed during field collections, in our study, we DNA-barcoded 1139 specimens belonging to 46 morphologically distinct fish species distributed throughout the NR basin by employing multiple analytical approaches. According to our analyses, DNA barcoding is an efficient method for the identification of fish by the presence of barcode gaps. However, three invasive species are characterized by deep conspecific divergences, generating multiple lineages and Operational Taxonomic Units (OTUs), implying the possibility of cryptic species. At the other end of the spectrum, ten species (from three genera) that are characterized by an overlap between their intra- and interspecific genetic distances form a single genetic cluster and share haplotypes. The neighbor-joining phenogram, Barcode Index Numbers (BINs) and Automatic Barcode Gap Discovery (ABGD) identified 43 putative species, while the General Mixed Yule-coalescence (GMYC) identified five more OTUs. Thus, our study established a reliable DNA barcode reference library for the fish in the NR and sheds new light on the local fish diversity.

The fish diversity in the upper reaches of the Salween River, Nujiang River, revealed by DNA barcoding

PubMed Central

Chen, Weitao; Ma, Xiuhui; Shen, Yanjun; Mao, Yuntao; He, Shunping

2015-01-01

Nujiang River (NR), an essential component of the biodiversity hotspot of the Mountains of Southwest China, possesses a characteristic fish fauna and contains endemic species. Although previous studies on fish diversity in the NR have primarily consisted of listings of the fish species observed during field collections, in our study, we DNA-barcoded 1139 specimens belonging to 46 morphologically distinct fish species distributed throughout the NR basin by employing multiple analytical approaches. According to our analyses, DNA barcoding is an efficient method for the identification of fish by the presence of barcode gaps. However, three invasive species are characterized by deep conspecific divergences, generating multiple lineages and Operational Taxonomic Units (OTUs), implying the possibility of cryptic species. At the other end of the spectrum, ten species (from three genera) that are characterized by an overlap between their intra- and interspecific genetic distances form a single genetic cluster and share haplotypes. The neighbor-joining phenogram, Barcode Index Numbers (BINs) and Automatic Barcode Gap Discovery (ABGD) identified 43 putative species, while the General Mixed Yule-coalescence (GMYC) identified five more OTUs. Thus, our study established a reliable DNA barcode reference library for the fish in the NR and sheds new light on the local fish diversity. PMID:26616046

Analysis of endangered Kansas fish species distribution during historical and contemporary periods (pre- and post-1969)

EPA Science Inventory

Background/Question/Methods Kansas has more freshwater fish species than other states in the west and northern US. More than 140 fishes have recently been documented in Kansas rivers; of these, at least five are categorized as endangered species in Kansas (and threatened species ...

76 FR 51352 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-18

... Department of Fish and Wildlife (WDFW), for a direct take permit pursuant to the Endangered Species Act of... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Section 9 of the ESA and Federal regulations prohibit the ``taking'' of a species listed as endangered or...

Multiplex PCR method for use in real-time PCR for identification of fish fillets from grouper (Epinephelus and Mycteroperca species) and common substitute species.

PubMed

Trotta, Michele; Schönhuth, Susana; Pepe, Tiziana; Cortesi, M Luisa; Puyet, Antonio; Bautista, José M

2005-03-23

Mitochondrial 16S rRNA sequences from morphological validated grouper (Epinephelus aeneus, E. caninus, E. costae, and E. marginatus; Mycteroperca fusca and M. rubra), Nile perch (Lates niloticus), and wreck fish (Polyprion americanus) were used to develop an analytical system for group diagnosis based on two alternative Polymerase Chain Reaction (PCR) approaches. The first includes conventional multiplex PCR in which electrophoretic migration of different sizes of bands allowed identification of the fish species. The second approach, involving real-time PCR, produced a single amplicon from each species that showed different Tm values allowing the fish groups to be directly identified. Real-time PCR allows the quick differential diagnosis of the three groups of species and high-throughput screening of multiple samples. Neither PCR system cross-reacted with DNA samples from 41 common marketed fish species, thus conforming to standards for species validation. The use of these two PCR-based methods makes it now possible to discriminate grouper from substitute fish species.

Parasites of native and exotic freshwater fishes in south-western Australia.

PubMed

Lymbery, A J; Hassan, M; Morgan, D L; Beatty, S J; Doupé, R G

2010-05-01

In this study, 1429 fishes of 18 different species (12 native and six exotic) were sampled from 29 localities to compare the levels of parasitism between native and exotic fish species and to examine the relationship between environmental degradation and parasite diversity. Forty-four putative species of parasites were found and most of these appear to be native parasites, which have not previously been described. Two parasite species, Lernaea cyprinacea and Ligula intestinalis, are probably introduced. Both were found on or in a range of native fish species, where they may cause severe disease. Levels of parasitism and parasite diversity were significantly greater in native fishes than in exotic species, and this may contribute to an enhanced demographic performance and competitive ability in invading exotics. Levels of parasitism and parasite diversity in native fishes were negatively related to habitat disturbance, in particular to a suite of factors that indicate increased human use of the river and surrounding environment. This was due principally to the absence in more disturbed habitats of a number of species of endoparasites with complex life cycles, involving transmission between different host species.

Examining the Impact of a Public Health Message on Fish Consumption in Bermuda

PubMed Central

McLean Pirkle, Catherine; Peek-Ball, Cheryl; Outerbridge, Eugene; Rouja, Philippe Max

2015-01-01

Background In 2003 mean cord blood mercury concentrations in pregnant Bermudian women exceeded levels associated with adverse health outcomes in children. The principal mercury source was local fish species. Public health messages were developed suggesting pregnant women reduce consumption of fish species with higher mercury concentrations (e.g. swordfish), substituting species containing lower mercury concentrations, and elevated omega-3 fatty acids (e.g. anchovies). Recent evidence indicates mercury concentrations in Bermuda’s pregnant women have fallen five- fold. Objectives Assess whether changes in women’s fish eating patterns during pregnancy are consistent with the public health messaging. Determine who is making changes to their diet during pregnancy and why. Methods Mixed methods study with a cross-sectional survey of 121 pregnant women, including 13 opened-ended interviews. Health system, social vulnerability, public health messaging, and socio-demographic variables were characterized and related to changes in fish consumption during pregnancy. Qualitative data were coded according to nutritional advice messages, comprehension of communication strategies, and sources of information. Results 95% of women surveyed encountered recommendations about fish consumption during pregnancy. 75% reported modifying fish eating behaviors because of recommendations. Principal sources of information about fish consumption in pregnancy were health care providers and the Internet. 71% of women reported reducing consumption of large fish species with greater mercury levels, but 60% reported reduced consumption of smaller, low mercury fish. No participant mentioned hearing about the benefits of fish consumption. More frequent exposure to public health messages during pregnancy was associated with lower reported consumption. Bermudian born women were less likely to reduce consumption of large fish species during pregnancy. Conclusions In Bermuda, public health messages advocating reduced consumption of larger, higher mercury-containing fish species appear effective, but masked the nutritional value message of small fish species, with low mercury concentration. Adjustment is needed to better balance the risk communication. PMID:26426692

Examining the Impact of a Public Health Message on Fish Consumption in Bermuda.

PubMed

McLean Pirkle, Catherine; Peek-Ball, Cheryl; Outerbridge, Eugene; Rouja, Philippe Max

2015-01-01

In 2003 mean cord blood mercury concentrations in pregnant Bermudian women exceeded levels associated with adverse health outcomes in children. The principal mercury source was local fish species. Public health messages were developed suggesting pregnant women reduce consumption of fish species with higher mercury concentrations (e.g. swordfish), substituting species containing lower mercury concentrations, and elevated omega-3 fatty acids (e.g. anchovies). Recent evidence indicates mercury concentrations in Bermuda's pregnant women have fallen five- fold. Assess whether changes in women's fish eating patterns during pregnancy are consistent with the public health messaging. Determine who is making changes to their diet during pregnancy and why. Mixed methods study with a cross-sectional survey of 121 pregnant women, including 13 opened-ended interviews. Health system, social vulnerability, public health messaging, and socio-demographic variables were characterized and related to changes in fish consumption during pregnancy. Qualitative data were coded according to nutritional advice messages, comprehension of communication strategies, and sources of information. 95% of women surveyed encountered recommendations about fish consumption during pregnancy. 75% reported modifying fish eating behaviors because of recommendations. Principal sources of information about fish consumption in pregnancy were health care providers and the Internet. 71% of women reported reducing consumption of large fish species with greater mercury levels, but 60% reported reduced consumption of smaller, low mercury fish. No participant mentioned hearing about the benefits of fish consumption. More frequent exposure to public health messages during pregnancy was associated with lower reported consumption. Bermudian born women were less likely to reduce consumption of large fish species during pregnancy. In Bermuda, public health messages advocating reduced consumption of larger, higher mercury-containing fish species appear effective, but masked the nutritional value message of small fish species, with low mercury concentration. Adjustment is needed to better balance the risk communication.

Genetic calibration of species diversity among North America's freshwater fishes.

PubMed

April, Julien; Mayden, Richard L; Hanner, Robert H; Bernatchez, Louis

2011-06-28

Freshwater ecosystems are being heavily exploited and degraded by human activities all over the world, including in North America, where fishes and fisheries are strongly affected. Despite centuries of taxonomic inquiry, problems inherent to species identification continue to hamper the conservation of North American freshwater fishes. Indeed, nearly 10% of species diversity is thought to remain undescribed. To provide an independent calibration of taxonomic uncertainty and to establish a more accessible molecular identification key for its application, we generated a standard reference library of mtDNA sequences (DNA barcodes) derived from expert-identified museum specimens for 752 North American freshwater fish species. This study demonstrates that 90% of known species can be delineated using barcodes. Moreover, it reveals numerous genetic discontinuities indicative of independently evolving lineages within described species, which points to the presence of morphologically cryptic diversity. From the 752 species analyzed, our survey flagged 138 named species that represent as many as 347 candidate species, which suggests a 28% increase in species diversity. In contrast, several species of parasitic and nonparasitic lampreys lack such discontinuity and may represent alternative life history strategies within single species. Therefore, it appears that the current North American freshwater fish taxonomy at the species level significantly conceals diversity in some groups, although artificially creating diversity in others. In addition to providing an easily accessible digital identification system, this study identifies 151 fish species for which taxonomic revision is required.

Native Larvivorous Fish in an Endemic Malarious Area of Southern Iran, a Biological Alternative Factor for Chemical Larvicides in Malaria Control Program

PubMed Central

SHAHI, Mehran; KAMRANI, Ehsan; SALEHI, Mehrdad; HABIBI, Reza; HANAFI-BOJD, Ahmad Ali

2015-01-01

Background: The widespread use of chemical insecticides, resistance in vectors and environmental problems, all have led to an increased interest in the use of biological agents in malaria control programs. The most important functional elements are the native fish. The aim of this study was to identify the native species of lavivorous fish in Rudan County, southern Iran, to introduce an effective species and to propose its’ implementation in the national malaria control program. Methods: This ecologically descriptive study was conducted during 2011–2012 using random sampling from different fish habitats of Rudan County. The shoals of fish were caught using fishing net. Fish samples were then identified in the Ichthyology lab, Department of Fisheries and the Environment, Hormozgan University. Results: Three species of larvivorous fish were identified as follows: Gambusia holbrooki, Aphaniusdispar dispar and Aphanius sp. The latter species has the most distribution in the study area and needs more morphological and molecular studies for identification at the species level. Conclusion: Two species of native fish, i.e., A. dispar and A. sp. with larvivorous potential live in the area. Further studies on their predatory property are recommended in order to apply this local potential against malaria vectors in the area. PMID:26744713

Composition of Fish Communities in a European Macrotidal Salt Marsh (the Mont Saint-Michel Bay, France)

NASA Astrophysics Data System (ADS)

Laffaille, P.; Feunteun, E.; Lefeuvre, J.-C.

2000-10-01

At least 100 fish species are known to be present in the intertidal areas (estuaries, mudflats and salt marshes) of Mont Saint-Michel Bay. These and other comparable shallow marine coastal waters, such as estuaries and lagoons, play a nursery role for many fish species. However, in Europe little attention has been paid to the value of tidal salt marshes for fishes. Between March 1996 and April 1999, 120 tides were sampled in a tidal creek. A total of 31 species were caught. This community was largely dominated by mullets ( Liza ramada represent 87% of the total biomass) and sand gobies ( Pomatoschistus minutus and P. lozanoi represent 82% of the total numbers). These species and also Gasterosteus aculeatus , Syngnathus rostellatus, Dicentrarchus labrax, Mugil spp., Liza aurata and Sprattus sprattus were the most frequent species (>50% of monthly frequency of occurrence). In Europe, salt marshes and their creeks are flooded only during high spring tides. So, fishes only invade this environment during short immersion periods, and no species can be considered as marsh resident. But, the salt marsh was colonized by fish every time the tide reached the creek, and during the short time of flood, dominant fishes fed actively and exploited the high productivity. Nevertheless, this study shows that there is little interannual variation in the fish community and there are three ' seasons ' in the fish fauna of the marsh. Marine straggler and marine estuarine dependent species colonize marshes between spring (recruitment period in the bay) and autumn before returning into deeper adjacent waters. Estuarine fishes are present all year round with maximum abundances in the end of summer. The presence of fishes confirms that this kind of wetland plays an important trophic and nursery role for these species. Differences in densities and stages distribution of these species into Mont Saint-Michel systems (tidal mudflats, estuaries and tidal salt marshes) can reduce the trophic competition.

Spatial variability in fish species assemblage and community structure in four subtropical lagoons of the Okavango Delta, Botswana

NASA Astrophysics Data System (ADS)

Mosepele, K.; Mosepele, B.; Bokhutlo, T.; Amutenya, K.

The species assemblage and community structure of four lagoons was assessed through time series data collected between 2001 and 2005 in the Okavango Delta. The main aim of this study was to evaluate the importance of lagoons as fish habitats in the Delta. Therefore, this study assessed the importance of these habitats through determining fish species diversity, composition, relative abundance, and community structure between the lagoons. Forty six species belonging to 11 families and five orders were collected over the study period. Main results showed that Cichlidae was the most important family and had the highest species richness in the lagoons. Significant differences ( p < 0.05) were observed in species richness, faunal composition, and diversity among some of the lagoons. Moreover, there were also variations in species composition, and also significant differences in mean length and weight of some selected fish species in the four lagoons. This study showed that lagoons are important repositories of food fish to local communities. Moreover, a management of the fish stocks based on restricting fishing in some lagoons as protected areas is not feasible because of these significant differences in species assemblages between lagoons. Furthermore, lagoons are subject to multiple where most of the lodges are constructed, which makes subsequently makes them vulnerable to pollution. Therefore, the integrity of lagoon habitats needs to be maintained so that their ecosystem functioning (i.e. fish repositories) is maintained.

Estimating the efficiency of fish cross-species cDNA microarray hybridization.

PubMed

Cohen, Raphael; Chalifa-Caspi, Vered; Williams, Timothy D; Auslander, Meirav; George, Stephen G; Chipman, James K; Tom, Moshe

2007-01-01

Using an available cross-species cDNA microarray is advantageous for examining multigene expression patterns in non-model organisms, saving the need for construction of species-specific arrays. The aim of the present study was to estimate relative efficiency of cross-species hybridizations across bony fishes, using bioinformatics tools. The methodology may serve also as a model for similar evaluations in other taxa. The theoretical evaluation was done by substituting comparative whole-transcriptome sequence similarity information into the thermodynamic hybridization equation. Complementary DNA sequence assemblages of nine fish species belonging to common families or suborders and distributed across the bony fish taxonomic branch were selected for transcriptome-wise comparisons. Actual cross-species hybridizations among fish of different taxonomic distances were used to validate and eventually to calibrate the theoretically computed relative efficiencies.

77 FR 63295 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-16

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... fish and wildlife permits (50 CFR parts 222-226). Those individuals requesting a hearing on an... 17428 The U.S. Fish and Wildlife Service, Sacramento Fish and Wildlife Office is requesting a 5-year...

Effects of acoustic alarms, designed to reduce small cetacean bycatch in gillnet fisheries, on the behaviour of North Sea fish species in a large tank.

PubMed

Kastelein, Ronald A; van der Heul, Sander; van der Veen, Jan; Verboom, Willem C; Jennings, Nancy; de Haan, Dick; Reijnders, Peter J H

2007-08-01

World-wide many cetaceans drown incidentally in fishing nets. To reduce the unwanted bycatch in gillnets, pingers (acoustic alarms) have been developed that are attached to the nets. In the European Union, pingers will be made compulsory in some areas in 2005 and in others in 2007. However, pingers may effect non-target marine fauna such as fish. Therefore in this study, the effects of seven commercially-available pingers on the behaviour of five North Sea fish species in a large tank were quantified. The species tested were: sea bass (Dicentrarchus labrax), pout (Trisopterus luscus), thicklip mullet (Chelon labrosus), herring (Clupea harengus), and cod (Gadus morhua). The fish were housed as single-species schools of 9-13 individuals in a tank. The behaviour of fish in quiet periods was compared with their behaviour during periods with active pingers. The results varied both between pingers and between fish species. Sea bass decreased their speed in response to one pinger and swam closer to the surface in response to another. Thicklip mullet swam closer to the bottom in response to two pingers and increased their swimming speed in response to one pinger. Herring swam faster in response to one pinger, and pout and cod (close relatives) showed no behavioural responses to any of the pingers. Of the seven pingers tested, four elicited responses in at least one fish species, and three elicited no responses. Whether similar responses would be elicited in these fish species in the wild, and if so, whether such responses would influence the catch rate of fisheries, cannot be derived from the results of this study. However, the results indicate the need for field studies with pingers and fish. Based on the small number of fish species tested, the present study suggests that the higher the frequency of a pinger, the less likely it is to affect the behaviour of marine fish.

Identifying Canadian Freshwater Fishes through DNA Barcodes

PubMed Central

Hubert, Nicolas; Hanner, Robert; Holm, Erling; Mandrak, Nicholas E.; Taylor, Eric; Burridge, Mary; Watkinson, Douglas; Dumont, Pierre; Curry, Allen; Bentzen, Paul; Zhang, Junbin; April, Julien; Bernatchez, Louis

2008-01-01

Background DNA barcoding aims to provide an efficient method for species-level identifications using an array of species specific molecular tags derived from the 5′ region of the mitochondrial cytochrome c oxidase I (COI) gene. The efficiency of the method hinges on the degree of sequence divergence among species and species-level identifications are relatively straightforward when the average genetic distance among individuals within a species does not exceed the average genetic distance between sister species. Fishes constitute a highly diverse group of vertebrates that exhibit deep phenotypic changes during development. In this context, the identification of fish species is challenging and DNA barcoding provide new perspectives in ecology and systematics of fishes. Here we examined the degree to which DNA barcoding discriminate freshwater fish species from the well-known Canadian fauna, which currently encompasses nearly 200 species, some which are of high economic value like salmons and sturgeons. Methodology/Principal Findings We bi-directionally sequenced the standard 652 bp “barcode” region of COI for 1360 individuals belonging to 190 of the 203 Canadian freshwater fish species (95%). Most species were represented by multiple individuals (7.6 on average), the majority of which were retained as voucher specimens. The average genetic distance was 27 fold higher between species than within species, as K2P distance estimates averaged 8.3% among congeners and only 0.3% among concpecifics. However, shared polymorphism between sister-species was detected in 15 species (8% of the cases). The distribution of K2P distance between individuals and species overlapped and identifications were only possible to species group using DNA barcodes in these cases. Conversely, deep hidden genetic divergence was revealed within two species, suggesting the presence of cryptic species. Conclusions/Significance The present study evidenced that freshwater fish species can be efficiently identified through the use of DNA barcoding, especially the species complex of small-sized species, and that the present COI library can be used for subsequent applications in ecology and systematics. PMID:22423312

Estimating the impact of oyster restoration scenarios on transient fish production

USGS Publications Warehouse

McCoy, Elizabeth; Borrett, Stuart R.; LaPeyre, Megan K.; Peterson, Bradley J.

2017-01-01

Oyster reef restoration projects are increasing in number both to enhance oyster density and to retain valuable ecosystem services provided by oyster reefs. Although some oyster restoration projects have demonstrated success by increasing density and biomass of transient fish, it still remains a challenge to quantify the effects of oyster restoration on transient fish communities. We developed a bioenergetics model to assess the impact of selected oyster reef restoration scenarios on associated transient fish species. We used the model to analyze the impact of changes in (1) oyster population carrying capacity; (2) oyster population growth rate; and (3) diet preference of transient fish on oyster reef development and associated transient fish species. Our model results indicate that resident fish biomass is directly affected by oyster restoration and oyster biomass, and oyster restoration can have cascading impacts on transient fish biomass. Furthermore, the results highlight the importance of a favorable oyster population growth rate during early restoration years, as it can lead to rapid increases in mean oyster biomass and biomass of transient fish species. The model also revealed that a transient fish's diet solely dependent on oyster reef-derived prey could limit the biomass of transient fish species, emphasizing the importance of habitat connectivity in estuarine areas to enhance transient fish species biomass. Simple bioenergetics models can be developed to understand the dynamics of a system and make qualitative predictions of management and restoration scenarios.

Relation between species assemblages of fishes and water quality in salt ponds and sloughs in South San Francisco Bay

USGS Publications Warehouse

Mejia, F.; Saiki, M.K.; Takekawa, John Y.

2008-01-01

This study was conducted to characterize fishery resources inhabiting salt-evaporation ponds and sloughs in South San Francisco Bay, and to identify key environmental variables that influence distribution of fishes. The ponds, which were originally constructed and operated for commercial production of salt, have undergone preliminary modifications (installation of culverts, gates, and other water-control structures) in preparation for full restoration to mostly tidal wetlands over the next 2 decades. We sampled fish from two salt-pond complexes (Alviso complex and Eden Landing complex), each consisting of several pond systems and their associated sloughs. Cluster analysis of species of fish indicated that at least two species assemblages were present, one characteristic of ponds and the other characteristic of sloughs and slough-like ponds. The slough-like ponds exhibited water-quality conditions (especially salinity) that resembled conditions found in the sloughs. Pond fishes were represented by 12 species, whereas slough fishes were represented by 22 species. Except for bay pipefish (Syngnathus leptorhynchus), which was unique to ponds, all species present in ponds also were in sloughs and slough-like ponds. These results indicated that species of fish in ponds originated from the sloughs. According to canonical-discriminant analysis, four environmental variables were useful for discriminating between the two species assemblages. Most discriminatory power was contributed by the index of habitat connectivity, a measure of minimum distance that a fish must travel to reach a particular pond from the nearest slough. Apparently, as fish from sloughs enter and move through interconnected salt ponds, environmental stress factors increase in severity until only the more tolerant species remain. The most likely source of stress is salinity, because this variable was second in importance to the index of habitat connectivity in discriminating between the two species assemblages. Water temperature and concentration of dissolved oxygen also seemingly influenced spatial distribution of fishes, although they were less important than salinity.

MiFish, a set of universal PCR primers for metabarcoding environmental DNA from fishes: detection of more than 230 subtropical marine species

PubMed Central

Miya, M.; Sato, Y.; Fukunaga, T.; Sado, T.; Poulsen, J. Y.; Sato, K.; Minamoto, T.; Yamamoto, S.; Yamanaka, H.; Araki, H.; Kondoh, M.; Iwasaki, W.

2015-01-01

We developed a set of universal PCR primers (MiFish-U/E) for metabarcoding environmental DNA (eDNA) from fishes. Primers were designed using aligned whole mitochondrial genome (mitogenome) sequences from 880 species, supplemented by partial mitogenome sequences from 160 elasmobranchs (sharks and rays). The primers target a hypervariable region of the 12S rRNA gene (163–185 bp), which contains sufficient information to identify fishes to taxonomic family, genus and species except for some closely related congeners. To test versatility of the primers across a diverse range of fishes, we sampled eDNA from four tanks in the Okinawa Churaumi Aquarium with known species compositions, prepared dual-indexed libraries and performed paired-end sequencing of the region using high-throughput next-generation sequencing technologies. Out of the 180 marine fish species contained in the four tanks with reference sequences in a custom database, we detected 168 species (93.3%) distributed across 59 families and 123 genera. These fishes are not only taxonomically diverse, ranging from sharks and rays to higher teleosts, but are also greatly varied in their ecology, including both pelagic and benthic species living in shallow coastal to deep waters. We also sampled natural seawaters around coral reefs near the aquarium and detected 93 fish species using this approach. Of the 93 species, 64 were not detected in the four aquarium tanks, rendering the total number of species detected to 232 (from 70 families and 152 genera). The metabarcoding approach presented here is non-invasive, more efficient, more cost-effective and more sensitive than the traditional survey methods. It has the potential to serve as an alternative (or complementary) tool for biodiversity monitoring that revolutionizes natural resource management and ecological studies of fish communities on larger spatial and temporal scales. PMID:26587265

Nonnative Fishes in the Upper Mississippi River System

USGS Publications Warehouse

Irons, Kevin S.; DeLain, Steven A.; Gittinger, Eric; Ickes, Brian S.; Kolar, Cindy S.; Ostendort, David; Ratcliff, Eric N.; Benson, Amy J.; Irons, Kevin S.

2009-01-01

The introduction, spread, and establishment of nonnative species is widely regarded as a leading threat to aquatic biodiversity and consequently is ranked among the most serious environmental problems facing the United States today. This report presents information on nonnative fish species observed by the Long Term Resource Monitoring Program on the Upper Mississippi River System a nexus of North American freshwater fish diversity for the Nation. The Long Term Resource Monitoring Program, as part of the U.S. Army Corps of Engineers' Environmental Management Plan, is the Nation's largest river monitoring program and stands as the primary source of standardized ecological information on the Upper Mississippi River System. The Long Term Resource Monitoring Program has been monitoring fish communities in six study areas on the Upper Mississippi River System since 1989. During this period, more than 3.5 million individual fish, consisting of 139 species, have been collected. Although fish monitoring activities of the Long Term Resource Monitoring Program focus principally on entire fish communities, data collected by the Program are useful for detecting and monitoring the establishment and spread of nonnative fish species within the Upper Mississippi River System Basin. Sixteen taxa of nonnative fishes, or hybrids thereof, have been observed by the Long Term Resource Monitoring Program since 1989, and several species are presently expanding their distribution and increasing in abundance. For example, in one of the six study areas monitored by the Long Term Resource Monitoring Program, the number of established nonnative species has increased from two to eight species in less than 10 years. Furthermore, contributions of those eight species can account for up to 60 percent of the total annual catch and greater than 80 percent of the observed biomass. These observations are critical because the Upper Mississippi River System stands as a nationally significant pathway for nonnative species expansion between the Mississippi River and the Great Lakes Basin. This report presents a synthesis of data on nonnative fish species observed during Long Term Resource Monitoring Program monitoring activities.

MiFish, a set of universal PCR primers for metabarcoding environmental DNA from fishes: detection of more than 230 subtropical marine species.

PubMed

Miya, M; Sato, Y; Fukunaga, T; Sado, T; Poulsen, J Y; Sato, K; Minamoto, T; Yamamoto, S; Yamanaka, H; Araki, H; Kondoh, M; Iwasaki, W

2015-07-01

We developed a set of universal PCR primers (MiFish-U/E) for metabarcoding environmental DNA (eDNA) from fishes. Primers were designed using aligned whole mitochondrial genome (mitogenome) sequences from 880 species, supplemented by partial mitogenome sequences from 160 elasmobranchs (sharks and rays). The primers target a hypervariable region of the 12S rRNA gene (163-185 bp), which contains sufficient information to identify fishes to taxonomic family, genus and species except for some closely related congeners. To test versatility of the primers across a diverse range of fishes, we sampled eDNA from four tanks in the Okinawa Churaumi Aquarium with known species compositions, prepared dual-indexed libraries and performed paired-end sequencing of the region using high-throughput next-generation sequencing technologies. Out of the 180 marine fish species contained in the four tanks with reference sequences in a custom database, we detected 168 species (93.3%) distributed across 59 families and 123 genera. These fishes are not only taxonomically diverse, ranging from sharks and rays to higher teleosts, but are also greatly varied in their ecology, including both pelagic and benthic species living in shallow coastal to deep waters. We also sampled natural seawaters around coral reefs near the aquarium and detected 93 fish species using this approach. Of the 93 species, 64 were not detected in the four aquarium tanks, rendering the total number of species detected to 232 (from 70 families and 152 genera). The metabarcoding approach presented here is non-invasive, more efficient, more cost-effective and more sensitive than the traditional survey methods. It has the potential to serve as an alternative (or complementary) tool for biodiversity monitoring that revolutionizes natural resource management and ecological studies of fish communities on larger spatial and temporal scales.

[Fish community structure and its seasonal change in subtidal sandy beach habitat off southern Gouqi Island].

PubMed

Wang, Zhen-Hua; Wang, Kai; Zhao, Jing; Zhang, Shou-Yu

2011-05-01

To understand the characteristics of fish community structure in sandy beach habitats of island reef water areas, and to evaluate the potential capacity of these habitats in local fish stock maintenance, fishes were monthly collected with multi-mesh trammel nets in 2009 from the subtidal sandy beach habitat off southern Gouqi Island, taking the adjacent rocky reef habitat as the control. alpha and beta species diversity indices, index of relative importance (IRI), relative catch rate, and dominance curve for abundance and biomass (ABC curve) were adopted to compare the fish species composition, diversity, and community pattern between the two habitats, and multivariate statistical analyses such as non-metric multidimensional scaling (nMDS) and cluster were conducted to discuss the fish assemblage patterns. A total of 63 fish species belonging to 11 orders, 38 families, and 56 genera were collected, of which, 46 fish species were appeared in the two habitats. Due to the appearance of more warm water species in sandy bottom, the fishes in subtidal sandy beach habitat showed much higher richness, and the abundance catch rate (ACR) from May to July was higher than that in rocky reef habitat. In most rest months, the ACR in subtidal sandy beach habitat also showed the similar trend. However, the species richness and diversity in spring and summer were significantly lower in subtidal sandy beach habitat than in rocky reef habitat, because of the high species dominance and low evenness in the sandy beach habitat. Japanese tonguefish (Paraplagusia japonica) was the indicator species in the sandy beach habitat, and dominated in early spring, later summer, autumn, and winter when the fishing pressure was not strong. In sandy bottom, a unique community structure was formed and kept in dynamic, due to the nursery use of sandy beach by Japanese anchovy (Engraulis japonicus) from May to July, the gathering of gray mullet (Mugil cephalus) in most months for feeding, and the large quantity appearance of plotosid catfish (Plotosus anguillaris) in early Autumn, which was quite different from the community structure pattern dominated by reef fishes in rocky-algae habitat. The subtidal sandy bottom off Gouqi Island was serving as both nursery and feeding grounds for many fish species, being a suitable habitat for flatfishes. It was concluded that the sandy beaches around Gouqi Island could be a very important habitat for economic fish species, especially as a nursery ground for juvenile fishes, contributing to the fish stock maintenance in specific area.

Fish extinctions alter nutrient recycling in tropical freshwaters.

PubMed

McIntyre, Peter B; Jones, Laura E; Flecker, Alexander S; Vanni, Michael J

2007-03-13

There is increasing evidence that species extinctions jeopardize the functioning of ecosystems. Overfishing and other human influences are reducing the diversity and abundance of fish worldwide, but the ecosystem-level consequences of these changes have not been assessed quantitatively. Recycling of nutrients is one important ecosystem process that is directly influenced by fish. Fish species vary widely in the rates at which they excrete nitrogen and phosphorus; thus, altering fish communities could affect nutrient recycling. Here, we use extensive field data on nutrient recycling rates and population sizes of fish species in a Neotropical river and Lake Tanganyika, Africa, to evaluate the effects of simulated extinctions on nutrient recycling. In both of these species-rich ecosystems, recycling was dominated by relatively few species, but contributions of individual species differed between nitrogen and phosphorus. Alternative extinction scenarios produced widely divergent patterns. Loss of the species targeted by fishermen led to faster declines in nutrient recycling than extinctions in order of rarity, body size, or trophic position. However, when surviving species were allowed to increase after extinctions, these compensatory responses had strong moderating effects even after losing many species. Our results underscore the complexity of predicting the consequences of extinctions from species-rich animal communities. Nevertheless, the importance of exploited species in nutrient recycling suggests that overfishing could have particularly detrimental effects on ecosystem functioning.

Predictive modeling of deep-sea fish distribution in the Azores

NASA Astrophysics Data System (ADS)

Parra, Hugo E.; Pham, Christopher K.; Menezes, Gui M.; Rosa, Alexandra; Tempera, Fernando; Morato, Telmo

2017-11-01

Understanding the link between fish and their habitat is essential for an ecosystem approach to fisheries management. However, determining such relationship is challenging, especially for deep-sea species. In this study, we applied generalized additive models (GAMs) to relate presence-absence and relative abundance data of eight economically-important fish species to environmental variables (depth, slope, aspect, substrate type, bottom temperature, salinity and oxygen saturation). We combined 13 years of catch data collected from systematic longline surveys performed across the region. Overall, presence-absence GAMs performed better than abundance models and predictions made for the observed data successfully predicted the occurrence of the eight deep-sea fish species. Depth was the most influential predictor of all fish species occurrence and abundance distributions, whereas other factors were found to be significant for some species but did not show such a clear influence. Our results predicted that despite the extensive Azores EEZ, the habitats available for the studied deep-sea fish species are highly limited and patchy, restricted to seamounts slopes and summits, offshore banks and island slopes. Despite some identified limitations, our GAMs provide an improved knowledge of the spatial distribution of these commercially important fish species in the region.

Trophic interactions between native and introduced fish species in a littoral fish community.

PubMed

Monroy, M; Maceda-Veiga, A; Caiola, N; De Sostoa, A

2014-11-01

The trophic interactions between 15 native and two introduced fish species, silverside Odontesthes bonariensis and rainbow trout Oncorhynchus mykiss, collected in a major fishery area at Lake Titicaca were explored by integrating traditional ecological knowledge and stable-isotope analyses (SIA). SIA suggested the existence of six trophic groups in this fish community based on δ(13)C and δ(15)N signatures. This was supported by ecological evidence illustrating marked spatial segregation between groups, but a similar trophic level for most of the native groups. Based on Bayesian ellipse analyses, niche overlap appeared to occur between small O. bonariensis (<90 mm) and benthopelagic native species (31.6%), and between the native pelagic killifish Orestias ispi and large O. bonariensis (39%) or O. mykiss (19.7%). In addition, Bayesian mixing models suggested that O. ispi and epipelagic species are likely to be the main prey items for the two introduced fish species. This study reveals a trophic link between native and introduced fish species, and demonstrates the utility of combining both SIA and traditional ecological knowledge to understand trophic relationships between fish species with similar feeding habits. © 2014 The Fisheries Society of the British Isles.

Mitochondrial DNA identification of game and harvested freshwater fish species.

PubMed

Kyle, C J; Wilson, C C

2007-02-14

The use of DNA in forensics has grown rapidly for human applications along with the concomitant development of bioinformatics and demographic databases to help fully realize the potential of this molecular information. Similar techniques are also used routinely in many wildlife cases, such as species identification in food products, poaching and the illegal trade of endangered species. The use of molecular techniques in forensic cases related to wildlife and the development of associated databases has, however, mainly focused on large mammals with the exception of a few high-profile species. There is a need to develop similar databases for aquatic species for fisheries enforcement, given the large number of exploited and endangered fish species, the intensity of exploitation, and challenges in identifying species and their derived products. We sequenced a 500bp fragment of the mitochondrial cytochrome b gene from representative individuals from 26 harvested fish taxa from Ontario, Canada, focusing on species that support major commercial and recreational fisheries. Ontario provides a unique model system for the development of a fish species database, as the province contains an evolutionarily diverse array of freshwater fish families representing more than one third of all freshwater fish in Canada. Inter- and intraspecific sequence comparisons using phylogenetic analysis and a BLAST search algorithm provided rigorous statistical metrics for species identification. This methodology and these data will aid in fisheries enforcement, providing a tool to easily and accurately identify fish species in enforcement investigations that would have otherwise been difficult or impossible to pursue.

Fish product mislabelling: failings of traceability in the production chain and implications for illegal, unreported and unregulated (IUU) fishing.

PubMed

Helyar, Sarah J; Lloyd, Hywel Ap D; de Bruyn, Mark; Leake, Jonathan; Bennett, Niall; Carvalho, Gary R

2014-01-01

Increasing consumer demand for seafood, combined with concern over the health of our oceans, has led to many initiatives aimed at tackling destructive fishing practices and promoting the sustainability of fisheries. An important global threat to sustainable fisheries is Illegal, Unreported and Unregulated (IUU) fishing, and there is now an increased emphasis on the use of trade measures to prevent IUU-sourced fish and fish products from entering the international market. Initiatives encompass new legislation in the European Union requiring the inclusion of species names on catch labels throughout the distribution chain. Such certification measures do not, however, guarantee accuracy of species designation. Using two DNA-based methods to compare species descriptions with molecular ID, we examined 386 samples of white fish, or products labelled as primarily containing white fish, from major UK supermarket chains. Species specific real-time PCR probes were used for cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) to provide a highly sensitive and species-specific test for the major species of white fish sold in the UK. Additionally, fish-specific primers were used to sequence the forensically validated barcoding gene, mitochondrial cytochrome oxidase I (COI). Overall levels of congruence between product label and genetic species identification were high, with 94.34% of samples correctly labelled, though a significant proportion in terms of potential volume, were mislabelled. Substitution was usually for a cheaper alternative and, in one case, extended to a tropical species. To our knowledge, this is the first published study encompassing a large-scale assessment of UK retailers, and if representative, indicates a potentially significant incidence of incorrect product designation.

Diversity "down under": monogeneans in the Antipodes (Australia) with a prediction of monogenean biodiversity worldwide.

PubMed

Whittington, I D

1998-10-01

There are approximately 25,000 species of fishes known in the world. The Monogenea are believed to be among the most host-specific of parasites and if each species of fish is host to a different species of monogenean, there could be almost 25,000 monogenean species on Earth. Currently, I estimate that between 3000 and 4000 of these are described. Australia has a rich marine fish fauna with approximately 3500 species of teleosts. If the same formula of one monogenean species per host fish species is applied, Australia marine fishes could host potentially 3500 species of monogeneans. The first monogenean species described from Australia was Encotyllabe pagrosomi MacCallum, 1917 and approximately 300 more species have since been described from the continent. Even in a region of Australia such as Heron Island on the Great Barrier Reef that has been a focus of sustained research on these parasites, only about 85 species are described from 40 of the most common, easily-caught species of fish. Reasons are discussed for the relatively small numbers of monogenean species described so far from Australia. Endemicity is difficult to judge, but only one is certain: Concinnocotyla australensis (Polystomatidae) from Neoceratodus forsteri (Dipnoi). Despite reductions in research funding, the value of parasite taxonomy must not be underestimated, particularly in regions of the world that have a rich diversity of potential hosts.

Evidence of indiscriminate fishing effects in one of the world's largest inland fisheries.

PubMed

Ngor, Peng Bun; McCann, Kevin S; Grenouillet, Gaël; So, Nam; McMeans, Bailey C; Fraser, Evan; Lek, Sovan

2018-06-12

While human impacts like fishing have altered marine food web composition and body size, the status of the world's important tropical inland fisheries remains largely unknown. Here, we look for signatures of human impacts on the indiscriminately fished Tonle Sap fish community that supports one of the world's largest freshwater fisheries. By analyzing a 15-year time-series (2000-2015) of fish catches for 116 species obtained from an industrial-scale 'Dai' fishery, we find: (i) 78% of the species exhibited decreasing catches through time; (ii) downward trends in catches occurred primarily in medium to large-bodied species that tend to occupy high trophic levels; (iii) a relatively stable or increasing trend in catches of small-sized species, and; (iv) a decrease in the individual fish weights and lengths for several common species. Because total biomass of the catch has remained remarkably resilient over the last 15 years, the increase in catch of smaller species has compensated for declines in larger species. Our finding of sustained production but altered community composition is consistent with predictions from recent indiscriminate theory, and gives a warning signal to fisheries managers and conservationists that the species-rich Tonle Sap is being affected by heavy indiscriminate fishing pressure.

Responses of coral reef fishes to past climate changes are related to life-history traits.

PubMed

Ottimofiore, Eduardo; Albouy, Camille; Leprieur, Fabien; Descombes, Patrice; Kulbicki, Michel; Mouillot, David; Parravicini, Valeriano; Pellissier, Loïc

2017-03-01

Coral reefs and their associated fauna are largely impacted by ongoing climate change. Unravelling species responses to past climatic variations might provide clues on the consequence of ongoing changes. Here, we tested the relationship between changes in sea surface temperature and sea levels during the Quaternary and present-day distributions of coral reef fish species. We investigated whether species-specific responses are associated with life-history traits. We collected a database of coral reef fish distribution together with life-history traits for the Indo-Pacific Ocean. We ran species distribution models (SDMs) on 3,725 tropical reef fish species using contemporary environmental factors together with a variable describing isolation from stable coral reef areas during the Quaternary. We quantified the variance explained independently by isolation from stable areas in the SDMs and related it to a set of species traits including body size and mobility. The variance purely explained by isolation from stable coral reef areas on the distribution of extant coral reef fish species largely varied across species. We observed a triangular relationship between the contribution of isolation from stable areas in the SDMs and body size. Species, whose distribution is more associated with historical changes, occurred predominantly in the Indo-Australian archipelago, where the mean size of fish assemblages is the lowest. Our results suggest that the legacy of habitat changes of the Quaternary is still detectable in the extant distribution of many fish species, especially those with small body size and the most sedentary. Because they were the least able to colonize distant habitats in the past, fish species with smaller body size might have the most pronounced lags in tracking ongoing climate change.

Mercury concentrations in Maine sport fishes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stafford, C.P.; Haines, T.A.

1997-01-01

To assess mercury contamination of fish in Maine, fish were collected from 120 randomly selected lakes. The collection goal for each lake was five fish of the single most common sport fish species within the size range commonly harvested by anglers. Skinless, boneless fillets of fish from each lake were composited, homogenized, and analyzed for total mercury. The two most abundant species, brook trout Salvelinus fontinalis and smallmouth bass Micropterus dolomieu, were also analyzed individually. The composite fish analyses indicate high concentrations of mercury, particularly in large and long-lived nonsalmonid species. Chain pickerel Esox niger, smallmouth bass, largemouth bass Micropterusmore » salmoides, and white perch Morone americana had the highest average mercury concentrations, and brook trout and yellow perch Perca flavescens had the lowest. The mean species composite mercury concentration was positively correlated with a factor incorporating the average size and age of the fish. Lakes containing fish with high mercury concentrations were not clustered near known industrial or population centers but were commonest in the area within 150 km of the seacoast, reflecting the geographical distribution of species that contained higher mercury concentrations. Stocked and wild brook trout were not different in length or weight, but wild fish were older and had higher mercury concentrations. Fish populations maintained by frequent introductions of hatchery-produced fish and subject to high angler exploitation rates may consist of younger fish with lower exposure to environmental mercury and thus contain lower concentrations than wild populations.« less

Influence of habitat structure on fish assemblage of an artificial reef in southern Brazil.

PubMed

Hackradt, Carlos Werner; Félix-Hackradt, Fabiana Cézar; García-Charton, José Antonio

2011-12-01

Habitat complexity strongly influences reef fish community composition. An understanding of the underlying reasons for this relationship is important for evaluating the suitability of artificial reef (AR) habitats as a marine resource management tool. We studied the influence of AR habitat structure on fish assemblage composition off the southern coast of Brazil. We found that reef blocks with greater area and number of holes possessed the greatest fish species richness and abundance. Reef blocks with greater complexity had higher abundance of almost 30% of fish species present. Natural reef (NR) and AR were different in their fish species composition, trophic structure and categories of water column occupancy by fish (spatial categories). Although NR was more diverse and harboured more trophic levels, AR presented the higher abundances and the presence of distinct fish species that underlined their importance at a regional scale. The greater availability of sheltering habitat where hard substrate is scarce, together with their frequent use by economically important species, make AR a useful tool for coastal management when certain ecological conditions are met. Copyright © 2011 Elsevier Ltd. All rights reserved.

Fish assemblages and environmental correlates in least-disturbed streams of the upper Snake River basin

USGS Publications Warehouse

Maret, T.R.; Robinson, C.T.; Minshall, G.W.

1997-01-01

Fish assemblages and environmental variables were evaluated from 37 least-disturbed, 1st- through 6th-order streams and springs in the upper Snake River basin, western USA. Data were collected as part of the efforts by the U.S. Geological Survey National Water Quality Assessment Program and the Idaho State University Stream Ecology Center to characterize aquatic biota and associated habitats in least-disturbed coldwater streams. Geographically, the basin comprises four ecoregions. Environmental variables constituting various spatial scales, from watershed characteristics to in stream habitat measures, were used to examine distribution patterns in fish assemblages. Nineteen fish species in the families Salmonidae, Cottidae, Cyprinidae, and Catostemidae were collected. Multivariate analyses showed high overlap in stream fish assemblages among the ecoregions. Major environmental factors determining species distributions in the basin were stream gradient, watershed size, conductivity, and percentage of the watershed covered by forest. Lowland streams (below 1,600 m in elevation), located mostly in the Snake River Basin/High Desert ecoregion, displayed different fish assemblages than upland streams (above 2,000 m elevation) in the Northern Rockies, Middle Rockies, and Northern Basin and Range ecoregions. For example, cotrids were not found in streams above 2,000 m in elevation. In addition, distinct fish assemblages were found in tributaries upstream and downstream from the large waterfall, Shoshone Falls, on the Snake River. Fish metrics explaining most of the variation among sites included the total number of species, number of native species, number of salmonid species, percent introduced species, percent cottids, and percent salmonids. Springs also exhibited different habitat conditions and fish assemblages than streams. The data suggest that the evolutionary consequences of geographic features and fish species introductions transcend the importance of ecoregion boundaries on fish distributions in the upper Snake River basin.

Determinants of fish assemblage structure in Northwestern Great Plains streams

USGS Publications Warehouse

Mullen, J.A.; Bramblett, R.G.; Guy, C.S.; Zale, A.V.; Roberts, D.W.

2011-01-01

Prairie streams are known for their harsh and stochastic physical conditions, and the fish assemblages therein have been shown to be temporally variable. We assessed the spatial and temporal variation in fish assemblage structure in five intermittent, adventitious northwestern Great Plains streams representing a gradient of watershed areas. Fish assemblages and abiotic conditions varied more spatially than temporally. The most important variables explaining fish assemblage structure were longitudinal position and the proportion of fine substrates. The proportion of fine substrates increased proceeding upstream, approaching 100% in all five streams, and species richness declined upstream with increasing fine substrates. High levels of fine substrate in the upper reaches appeared to limit the distribution of obligate lithophilic fish species to reaches further downstream. Species richness and substrates were similar among all five streams at the lowermost and uppermost sites. However, in the middle reaches, species richness increased, the amount of fine substrate decreased, and connectivity increased as watershed area increased. Season and some dimensions of habitat (including thalweg depth, absolute distance to the main-stem river, and watershed size) were not essential in explaining the variation in fish assemblages. Fish species richness varied more temporally than overall fish assemblage structure did because common species were consistently abundant across seasons, whereas rare species were sometimes absent or perhaps not detected by sampling. The similarity in our results among five streams varying in watershed size and those from other studies supports the generalization that spatial variation exceeds temporal variation in the fish assemblages of prairie and warmwater streams. Furthermore, given longitudinal position, substrate, and stream size, general predictions regarding fish assemblage structure and function in prairie streams are possible. ?? American Fisheries Society 2011.

An assessment of fish assemblage structure in a large river

USGS Publications Warehouse

Kiraly, Ian A.; Coghlan, S.M.; Zydlewski, Joseph D.; Hayes, D.

2015-01-01

The Penobscot River drains the largest watershed in Maine and once provided spawning and rearing habitats to 11 species of diadromous fishes. The construction of dams blocked migrations of these fishes and likely changed the structure and function of fish assemblages throughout the river. The proposed removal of two main-stem dams, improved upstream fish passage at a third dam, and construction of a fish bypass on a dam obstructing a major tributary is anticipated to increase passage of and improve habitat connectivity for both diadromous and resident fishes. We captured 61 837 fish of 35 species in the Penobscot River and major tributaries, through 114 km of boat electrofishing. Patterns of fish assemblage structure did not change considerably during our sampling; relatively few species contributed to seasonal and annual variability within the main-stem river, including smallmouth bass Micropterus dolomieu, white sucker Catostomus commersonii, pumpkinseed Lepomis gibbosus, and golden shiner Notemigonus crysoleucas. However, distinct fish assemblages were present among river sections bounded by dams. Many diadromous species were restricted to tidal waters downriver of the Veazie Dam; Fundulus species were also abundant within the tidal river section. Smallmouth bass and pumpkinseed were most prevalent within the Veazie Dam impoundment and the free-flowing river section immediately upriver, suggesting the importance of both types of habitat that supports multiple life stages of these species. Further upriver, brown bullhead Ameiurus nebulosus, yellow perch Perca flavescens, chain pickerel Esox niger, and cyprinid species were more prevalent than within any other river section. Our findings describe baseline spatial patterns of fish assemblages in the Penobscot River in relation to dams with which to compare assessments after dam removal occurs.

[Distribution of coccidians (Sporozoa: Coccidiida) in various systematic groups of fishes].

PubMed

Belova, L M; Krylov, M V

2000-01-01

There are about 250 coccidian species associated with fishes. They belong to 8 genera (Calyptospora, Cryptosporidium, Crystallospora, Eimeria, Epieimeria, Goussia, Isospora, Octosporella) and 3 families (Calyptosporidae, Cryptosporidiidae, Eimeriidae). Two genera are represented by great number of species associated with fishes: Eimeria--157 and Goussia--69 species. Most diverse fauna of coccidians was found in fishes of the class Actinopterigii; fishes of the class Elasmobranchii have significantly less number of coccidians. These parasites have never been recorded on the class Holocephali. Coccidian have been recorded in 55 orders of fishes. Within the Actinopterigii, the richest coccidian fauna is recorded from Cypriniformes and Perciformes. Accumulated data on host associations proves that coccidian species have mainly a restricted hosts specificity.

A comparative study of Northern Ireland's estuaries based on the results of beam trawl fish surveys

NASA Astrophysics Data System (ADS)

Harrison, Trevor D.; Armour, Neil D.; McNeill, Michael T.; Moorehead, Peter W.

2017-11-01

The fish communities of Northern Ireland's estuaries were described and compared using data collected with a modified beam trawl over a six year period from 2009 to 2014. Multivariate analyses identified four estuary groups based on variations in their physico-chemical attributes. These groups broadly corresponded with the distribution and variation of estuary geomorphic types identified around the Irish coast. The dominant fish species captured were also among the main species reported in other North East Atlantic estuaries. A significant link between the estuary types and their fish communities was found; each estuary group contained a somewhat distinctive fish community. The fish communities also showed a significant relationship with the physico-chemical characteristics of the estuaries. Differences in fish species composition are attributed to habitat and environmental preferences of key estuary-associated species.

Modeling the relations between flow regime components, species traits, and spawning success of fishes in warmwater streams

USGS Publications Warehouse

Craven, S.W.; Peterson, J.T.; Freeman, Mary C.; Kwak, T.J.; Irwin, E.

2010-01-01

Modifications to stream hydrologic regimes can have a profound influence on the dynamics of their fish populations. Using hierarchical linear models, we examined the relations between flow regime and young-of-year fish density using fish sampling and discharge data from three different warmwater streams in Illinois, Alabama, and Georgia. We used an information theoretic approach to evaluate the relative support for models describing hypothesized influences of five flow regime components representing: short-term high and low flows; short-term flow stability; and long-term mean flows and flow stability on fish reproductive success during fish spawning and rearing periods. We also evaluated the influence of ten fish species traits on fish reproductive success. Species traits included spawning duration, reproductive strategy, egg incubation rate, swimming locomotion morphology, general habitat preference, and food habits. Model selection results indicated that young-of-year fish density was positively related to short-term high flows during the spawning period and negatively related to flow variability during the rearing period. However, the effect of the flow regime components varied substantially among species, but was related to species traits. The effect of short-term high flows on the reproductive success was lower for species that broadcast their eggs during spawning. Species with cruiser swimming locomotion morphologies (e.g., Micropterus) also were more vulnerable to variable flows during the rearing period. Our models provide insight into the conditions and timing of flows that influence the reproductive success of warmwater stream fishes and may guide decisions related to stream regulation and management. ?? 2010 US Government.

Reef Fishes in Biodiversity Hotspots Are at Greatest Risk from Loss of Coral Species

PubMed Central

Holbrook, Sally J.; Schmitt, Russell J.; Messmer, Vanessa; Brooks, Andrew J.; Srinivasan, Maya; Munday, Philip L.; Jones, Geoffrey P.

2015-01-01

Coral reef ecosystems are under a variety of threats from global change and anthropogenic disturbances that are reducing the number and type of coral species on reefs. Coral reefs support upwards of one third of all marine species of fish, so the loss of coral habitat may have substantial consequences to local fish diversity. We posit that the effects of habitat degradation will be most severe in coral regions with highest biodiversity of fishes due to greater specialization by fishes for particular coral habitats. Our novel approach to this important but untested hypothesis was to conduct the same field experiment at three geographic locations across the Indo-Pacific biodiversity gradient (Papua New Guinea; Great Barrier Reef, Australia; French Polynesia). Specifically, we experimentally explored whether the response of local fish communities to identical changes in diversity of habitat-providing corals was independent of the size of the regional species pool of fishes. We found that the proportional reduction (sensitivity) in fish biodiversity to loss of coral diversity was greater for regions with larger background species pools, reflecting variation in the degree of habitat specialization of fishes across the Indo-Pacific diversity gradient. This result implies that habitat-associated fish in diversity hotspots are at greater risk of local extinction to a given loss of habitat diversity compared to regions with lower species richness. This mechanism, related to the positive relationship between habitat specialization and regional biodiversity, and the elevated extinction risk this poses for biodiversity hotspots, may apply to species in other types of ecosystems. PMID:25970588

Reef fishes in biodiversity hotspots are at greatest risk from loss of coral species.

PubMed

Holbrook, Sally J; Schmitt, Russell J; Messmer, Vanessa; Brooks, Andrew J; Srinivasan, Maya; Munday, Philip L; Jones, Geoffrey P

2015-01-01

Coral reef ecosystems are under a variety of threats from global change and anthropogenic disturbances that are reducing the number and type of coral species on reefs. Coral reefs support upwards of one third of all marine species of fish, so the loss of coral habitat may have substantial consequences to local fish diversity. We posit that the effects of habitat degradation will be most severe in coral regions with highest biodiversity of fishes due to greater specialization by fishes for particular coral habitats. Our novel approach to this important but untested hypothesis was to conduct the same field experiment at three geographic locations across the Indo-Pacific biodiversity gradient (Papua New Guinea; Great Barrier Reef, Australia; French Polynesia). Specifically, we experimentally explored whether the response of local fish communities to identical changes in diversity of habitat-providing corals was independent of the size of the regional species pool of fishes. We found that the proportional reduction (sensitivity) in fish biodiversity to loss of coral diversity was greater for regions with larger background species pools, reflecting variation in the degree of habitat specialization of fishes across the Indo-Pacific diversity gradient. This result implies that habitat-associated fish in diversity hotspots are at greater risk of local extinction to a given loss of habitat diversity compared to regions with lower species richness. This mechanism, related to the positive relationship between habitat specialization and regional biodiversity, and the elevated extinction risk this poses for biodiversity hotspots, may apply to species in other types of ecosystems.

Fish assemblages and habitat relationships in a small northern Great Plains stream

USGS Publications Warehouse

Barfoot, C.A.; White, R.G.

1999-01-01

We examined fish populations and environmental characteristics of pool and riffle habitats of Little Beaver Creek, Montana, a small northern Great Plains stream. We collected 4,980 fishes representing 20 species in eight families. The most abundant and species-rich family was Cyprinidae. Nearly 88% (4,369) of all fishes were collected in pools. Pools also supported greater numbers ofspecies (x = 6.3, SO = 2.6, n = 58) than did riffles ( x = 2.2, SO = 1.9, n = 47). Most species showed distinct patterns of relative abundance along the stream gradient. Community changes were primarily reflected by the downstream addition of species; species replacement was of less importance. A multivariate analysis of fish relative abundance identified two relatively well-defined pool fish assemblages: a downstream assemblage comprised largely of native fluvial cyprinids, and a more diverse midstream-upstream assemblage comprised of fishes from several families. No well-defined assemblages were identified in riffle habitats. Environmental measures of stream size, substrate characteristics, water clarity, and banks ide conditions appeared to be associated with differences in fish assemblage structure. However, correlations between habitat conditions and fish assemblages were weak, possibly because a complex of factors act conculTently to shape assemblages.

Effects of processing on the proximate and metal contents in three fish species from Nigerian coastal waters

PubMed Central

Bassey, Francisca I; Oguntunde, Fehintola C; Iwegbue, Chukwujindu M A; Osabor, Vincent N; Edem, Christopher A

2014-01-01

The effects of culinary practices such as boiling, frying, and grilling on the proximate compositions and concentrations of metals (Cd, Pb, Cr, Zn, Fe, Cu, Mn, Ni, and Hg) in commonly consumed fish species from the Nigerian coastal waters were investigated. The selected fish species were Polydactylus quadratifilis, Chrysicthys nigrodigitatus and Cynoglossus senegalensis. The culinary practices lead to increased protein, fat, and ash contents and decreased moisture contents of these fish species. The culinary practices resulted significant increase in the concentrations of most of the studied metals and decrease in the concentrations of Fe, Cr, and Pb in some fish types. The concentrations and estimated dietary intakes of Cd, Pb, Cr, Zn, Fe, Cu, Mn, Ni, and Hg from consumption of the processed fish were within their statutory safe limits. The individual metal target hazard quotient (THQ) values and the total THQs were less than 1 which indicates that no health risks would arise from the long-term consumption of these fish species. PMID:24936297

[Spatio-temporal dynamics of fishing effort in a multi-species artisanal diving fishery and its effects on catch variability: insights for sustainable management].

PubMed

Naranjo Madrigall, Helven; Salas Marquez, Silvia

2014-12-01

Artisanal diving fisheries are a source of income, employment and food security of coastal areas in many countries. Understanding the dynamics of these fisheries, including the spatial and temporal dynamics of fishing effort, gears and species can help to address the challenges involved in fisheries management. We aimed to analyze the differences in fishing strategies undertaken by fishers that use two different diving methods (hookah and free diving), the conditions and their potential impacts on catches when adjustments to those strategies are applied over time. For this, detailed information of fishing operations from artisanal boats in the North Pacific coast of Costa Rica was analyzed in two fishing seasons (2007-2008 and 2011-2012). Data were collected by onboard observers (fishing site, fishing time, species composition, depth and visibility). Additionally, interviews with divers were applied to obtain information of price per species, species volume and fishing operations. From the total number of trips during both seasons, hookah diving was represented by a sample size of 69.3%, while free diving, with a sample of 41.9%. More than 15 species were identified in each fishing season. Nevertheless, three categories had substantial contributions in both seasons with differences in the proportions for each case: green lobster (Panulirus gracilis), octopus (Octopus sp.) and parrotfish (Scarus perrico and S. ghobban). It is worth noting that an important proportion of catch was retained by fishers for personal consumption purposes, including species of high commercial value. Additional night diving activity, increased the number of dives from one season to another. Besides, cooperation processes in free diving fishing operations, and changes in fishing effort between seasons, defined important changes in fishing strategies. Potential causes of changes in fishing strategies and the implications for management to ensure the sustainability of these fisheries in the long term are discussed.

Ontogenetic, spatial and temporal variation in trophic level and diet of Chukchi Sea fishes

NASA Astrophysics Data System (ADS)

Marsh, Jennifer M.; Mueter, Franz J.; Iken, Katrin; Danielson, Seth

2017-01-01

Climate warming and increasing development are expected to alter the ecosystem of the Chukchi Sea, including its fish communities. As a component of the Arctic Ecosystem Integrated Survey, we assessed the ontogenetic, spatial and temporal variability of the trophic level and diet of key fish species in the Chukchi Sea using N and C stable isotopes. During August and September of 2012 and 2013, 16 common fish species and two primary, invertebrate consumers were collected from surface, midwater and bottom trawls within the eastern Chukchi Sea. Linear mixed-effects models were used to detect possible variation in the relationship between body length and either δ13C or δ15N values among water masses and years for 13 fish species with an emphasis on Arctic cod (Boreogadus saida). We also examined the fish community isotopic niche space, trophic redundancy, and trophic separation within each water mass as measures of resiliency of the fish food web. Ontogenetic shifts in trophic level and diet were observed for most species and these changes tended to vary by water mass. As they increased in length, most fish species relied more on benthic prey with the exception of three forage fish species (walleye pollock, Gadus chalcogrammus, capelin, Mallotus villosus, and Pacific sandlance, Ammodytes hexapterus). Species that exhibited interannual differences in diet and trophic level were feeding at lower trophic levels and consumed a more pelagic diet in 2012 when zooplankton densities were higher. Fish communities occupied different isotopic niche spaces depending on water mass association. In more northerly Arctic waters, the fish community occupied the smallest isotopic niche space and relied heavily on a limited range of intermediate δ13C prey, whereas in warmer, nutrient-rich Bering Chukchi Summer Water, pelagic prey was important. In the warmest, Pacific-derived coastal water, fish consumed both benthic and pelagic prey. Examining how spatial gradients in trophic position are linked to environmental drivers can provide insight into potential fish community shifts with a changing climate.

[Seasonal changes of fish species composition and diversity in mudflat wetlands of Hangzhou Bay].

PubMed

Jia, Xing-huan; Zhang, Heng; Jiang, Ke-yi; Wu, Ming

2010-12-01

In order to understand the spatiotemporal variation of fish species composition and biodiversity in the mudflat wetlands of Hangzhou Bay, thirty six surveys were conducted in the mudflat area, inning area, and aquaculture area in the south bank of the Bay in. March (early spring), May (spring), July (summer), and October (autumn), 2009. A total of 41 species belonging to 9 orders and 16 families were observed, among which, Cyprinid had the largest species number (14 species, 33.3% of the total), followed by Gobiidae (8 species, 19.1%). According to the lifestyle of fish, these 41 species could be divided into five ecological types, i.e., freshwater type (21 species), brackish-water type (16 species), inshore type (2 species), anadromous type (Coilia ectenes), and catadromios type (Anguilla japonica). The fish abundance was the highest (54. 5 fish per net) in summer, followed by in spring and autumn, and the lowest (17.7 fish per net) in early spring. In the three habitats, mudflat area and inning area had the similar seasonal change of fish abundance, i.e., the lowest in early spring, the highest in summer, and then decreased in autumn. Only two or three species were the dominant species in different seasons. In mudflat area, the dominant species were Mugil cephalus and Liza carinatus; while in inning and aquaculture areas, the dominant species were Carassius auratus, Hemiculter leucisculus, and Pseudorasbora parva. The values of Margalef's richness index (D), Pielou's evenness index (J), and Shannon index (H) were lower in March than in other months, but had no significant differences among May, July, and October (P > 0.05). The H value ranged in 0. 27-2. 13, being the lowest in March and higher in May and October (1.66 and 1.63, respectively). Overall, the fish abundance and biodiversity in the mudflat wetlands of Hangzhou Bay had apparent seasonal changes.

Decline of a diverse fish fauna: patterns of imperilment and protection in the Southeastern United States

Treesearch

Melvin L. Warren; Paul L. Angermeier; Brooks M. Burr; Wendell R. Haag

1997-01-01

The Southeastern United States harbors the richest freshwater fish fauna on the North American continent north of Mexico, but portents of decline of this great fauna are increasingly acknowledged. Southeastern fishes (493 species) comprise about 47 percent of the North American fish fauna (1,061 species) and 62 percent of the fauna in the United States (790 species)....

50 CFR 622.7 - Fishing years.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Fishing years. 622.7 Section 622.7... § 622.7 Fishing years. The fishing year for species or species groups governed in this part is January 1...) King and Spanish mackerel. The fishing year for the king and Spanish mackerel bag limits specified in...

50 CFR 622.30 - Fishing years.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Fishing years. 622.30 Section 622.30... Fishing years. The fishing year for species or species groups governed in this part is January 1 through... Spanish mackerel. The fishing year for the king and Spanish mackerel bag limits specified in § 622.39(c)(1...

50 CFR 622.30 - Fishing years.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Fishing years. 622.30 Section 622.30... Fishing years. The fishing year for species or species groups governed in this part is January 1 through... Spanish mackerel. The fishing year for the king and Spanish mackerel bag limits specified in § 622.39(c)(1...

50 CFR 622.7 - Fishing years.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Fishing years. 622.7 Section 622.7... § 622.7 Fishing years. The fishing year for species or species groups governed in this part is January 1...) King and Spanish mackerel. The fishing year for the king and Spanish mackerel bag limits specified in...

78 FR 59005 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-25

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... with Section 10(a)(1)(A) of the ESA of 1973 (16 U.S.C. 1531-1543) and regulations governing listed fish.... Applications Received Permit 1415 The U.S. Fish and Wildlife Services' (USFWS) Red Bluff Fish and Wildlife...

76 FR 27017 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-10

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... governing listed fish and wildlife permits (50 CFR 222-226). NMFS issues permits based on findings that such... in the area. The UW proposes to capture fish using enclosure nets and beach seines. The captured fish...

Ecological correlates of fish movement in a network of Virginia streams

USGS Publications Warehouse

Albanese, B.; Angermeier, P.L.; Dorai-Raj, S.

2004-01-01

Identifying factors that influence fish movement is a key step in predicting how populations respond to environmental change. Using mark-recapture (four species) and trap capture (eight species) data, we examined relationships between three attributes of movement and 15 ecological variables. The probability of emigrating from a reach was positively related to intermittency (one species) and body size (one species) and negatively related to distance from the mainstem creek (two species) and habitat complexity (one species). The number of fish moving upstream through traps was positively related to increases in flow (five species), day length (three species), and water temperature (two species); the number moving through downstream traps was positively associated with increases in flow (three species). Distance moved was greater for fish moving through unsuitable reaches (one species). Floods have a pervasive effect on fish movement, and human activities that affect flows will have widespread implications. The importance of other factors varies interspecifically, which may translate into variation in persistence and colonization rates. For example, species that exhibit reach fidelity in complex habitats may increase movement if habitats are homogenized. These species may suffer population declines because of the cost of increased movement and may ultimately be replaced by ecological generalists.

Balancing the risks and the benefits of local fish consumption in Bermuda.

PubMed

Dewailly, E; Rouja, P; Dallaire, R; Pereg, D; Tucker, T; Ward, J; Weber, J P; Maguire, J S; Julien, P

2008-11-01

Fish consumption today is widely recognized as highly beneficial since it constitutes a good source of several essential nutrients, such as selenium and polyunsaturated fatty acids (n-3 PUFA). However, fish can also contain contaminants such as mercury, which make the consumer, especially pregnant women, confused about the risk-benefit balance associated with fish consumption. This is particularly true for tropical fish species for which little information is available. We have previously reported that some Bermudian neonates had elevated mercury in their umbilical blood compared with international guidelines. The objective of this study was to give precise and balanced information on the content of mercury, selenium and PUFA in the most consumed fish species in Bermuda. In 2003 and 2006, a total of 307 fish were collected from 43 fish species and 351 samples were analysed (305 flesh samples, 44 liver samples, one roe and one fat sample) by inductively coupled plasma-mass spectrometry (ICP-MS) (metals) and high-resolution gas chromatography (HRGC) (fatty acids). Results show that mercury varies among species from 0.03 to 3.3 microg g(-1) and that it is possible for at-risk groups such as pregnant women to make informed choices concerning fish consumption, e.g. maximizing fish species rich in nutrients and low in mercury.

DNA barcoding of marine ornamental fishes from India.

PubMed

Bamaniya, Dhaval C; Pavan-Kumar, A; Gireesh-Babu, P; Sharma, Niti; Reang, Dhalongsaih; Krishna, Gopal; Lakra, W S

2016-09-01

India has rich marine ornamental fish diversity with 400 fish species distributed in Gulf of Munnar/Palk Bay, Gulf of Kutch, and in reefs around Andaman & Nicobar and Lakshadweep Islands. Marine ornamental fish identification at the field level is very difficult because of their high diversity and profound changes in appearance during their developmental stages and camouflage. To facilitate ornamental fish trading with ease and in compliance with the biodiversity act, DNA barcoding technique could be used to accurately identify species. In this study, DNA barcodes were generated for 31 species of commercially important marine ornamental fishes from India. The average genetic distance (K2P model) within species, genus, and family was 0.446, 13.08, and 20.09%, respectively. Intraspecific variation has increased several folds (15-20 times) after including conspecific sequences from different geographical locations. The presence of allopatric lineages/cryptic species was observed in the Indo-pacific region. The NJ tree constructed based on K2P values showed distinct clusters shared by congeneric species specific to populations.

Trophic structure of the Barents Sea fish assemblage with special reference to the cod stock recoverability

NASA Astrophysics Data System (ADS)

Dolgov, Andrey V.

2009-04-01

The species composition and trophic structure of the Barents Sea fish assemblage is analysed based on data from research survey trawls and diet analyses of various species. Atlantic cod was the dominant fish species encountered, accounting for more than 55% by abundance or biomass. Only five fish species (long rough dab, thorny skate, Greenland halibut, deepwater redfish and saithe) were sufficiently abundant to be considered as possible food competitors with cod in the Barents Sea. However, possible trophic competition is not high, due to low spatial and temporal overlap between cod and these other species. Analyses of fish assemblages and trophic structures of the Barents Sea and other areas (North Sea, Western Greenland, Newfoundland-Labrador shelf) suggest that Barents Sea cod is the only cod stock for which the ability to recover may not be restricted by trophic relations among fishes, due to a lack of other abundant predatory species and low potential for competition caused by spatial-temporal changes.

Reproduction and community structure of fish from winter catch sites from industrial shrimp bycatch from the northeast and southeast Mexican Pacific

PubMed Central

Muñoz-Garcia, Isabel Rosario; Martinez-Perez, Francisco; Ramirez-Perez, Jorge Saul

2018-01-01

The shrimp fishery is one of the most important fisheries in the world, although the low selectivity from trawling nets has led to the capture of a large number of non-target species. Shrimp-bycatch species include a large number of fish and invertebrate species, of which fish species are the most abundant. The present study aims to determine the community structure as well as the average sizes at first maturity of the fish species from shrimp-bycatch caught from industrial fisheries in the Mexican Pacific from Sinaloa to Guerrero, from January to March 2015. The shrimp-bycatch fish diversity value was found to be 2.22. A total of 37 species of finfish were found, of which five were considered rare. The fish species with the highest Importance Value Index (IVI) levels were Pseudupeneus grandisquamis, Paralichthys woolmani, Lutjanus peru and Diapterus peruvianus. The average size at first maturity was calculated for all species. Of the analysed organisms, 90% were in the juvenile stage, including species with riverine and artisanal fisheries. The present study demonstrates the risk within marine populations to different non-target species due to the poor selectivity of shrimp trawls. PMID:29507841

Is There a Relationship between Fish Cannibalism and Latitude or Species Richness?

PubMed

Pereira, Larissa Strictar; Keppeler, Friedrich Wolfgang; Agostinho, Angelo Antonio; Winemiller, Kirk O

2017-01-01

Cannibalism has been commonly observed in fish from northern and alpine regions and less frequently reported for subtropical and tropical fish in more diverse communities. Assuming all else being equal, cannibalism should be more common in communities with lower species richness because the probability of encountering conspecific versus heterospecific prey would be higher. A global dataset was compiled to determine if cannibalism occurrence is associated with species richness and latitude. Cannibalism occurrence, local species richness and latitude were recorded for 4,100 populations of 2,314 teleost fish species. Relationships between cannibalism, species richness and latitude were evaluated using generalized linear mixed models. Species richness was an important predictor of cannibalism, with occurrences more frequently reported for assemblages containing fewer species. Cannibalism was positively related with latitude for both marine and freshwater ecosystems in the Northern Hemisphere, but not in the Southern Hemisphere. The regression slope for the relationship was steeper for freshwater than marine fishes. In general, cannibalism is more frequent in communities with lower species richness, and the relationship between cannibalism and latitude is stronger in the Northern Hemisphere. In the Southern Hemisphere, weaker latitudinal gradients of fish species richness may account for the weak relationship between cannibalism and latitude. Cannibalism may be more common in freshwater than marine systems because freshwater habitats tend to be smaller and more closed to dispersal. Cannibalism should have greatest potential to influence fish population dynamics in freshwater systems at high northern latitudes.

Is There a Relationship between Fish Cannibalism and Latitude or Species Richness?

PubMed Central

Keppeler, Friedrich Wolfgang; Agostinho, Angelo Antonio; Winemiller, Kirk O.

2017-01-01

Cannibalism has been commonly observed in fish from northern and alpine regions and less frequently reported for subtropical and tropical fish in more diverse communities. Assuming all else being equal, cannibalism should be more common in communities with lower species richness because the probability of encountering conspecific versus heterospecific prey would be higher. A global dataset was compiled to determine if cannibalism occurrence is associated with species richness and latitude. Cannibalism occurrence, local species richness and latitude were recorded for 4,100 populations of 2,314 teleost fish species. Relationships between cannibalism, species richness and latitude were evaluated using generalized linear mixed models. Species richness was an important predictor of cannibalism, with occurrences more frequently reported for assemblages containing fewer species. Cannibalism was positively related with latitude for both marine and freshwater ecosystems in the Northern Hemisphere, but not in the Southern Hemisphere. The regression slope for the relationship was steeper for freshwater than marine fishes. In general, cannibalism is more frequent in communities with lower species richness, and the relationship between cannibalism and latitude is stronger in the Northern Hemisphere. In the Southern Hemisphere, weaker latitudinal gradients of fish species richness may account for the weak relationship between cannibalism and latitude. Cannibalism may be more common in freshwater than marine systems because freshwater habitats tend to be smaller and more closed to dispersal. Cannibalism should have greatest potential to influence fish population dynamics in freshwater systems at high northern latitudes. PMID:28122040

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Northwest), Pacific Oyster

DTIC Science & Technology

1988-09-01

Requirements of Coastal Fishes o and Invertebrates (Pacific Northwest) LEICT o PACIFIC OYSTER E2I 8 Coastal Ecology Group Fish and Wildlife Service Waterways...Profiles-: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific N rthwest) PACIFIC OYSTER by Gilbert B. Pauley...Fish and Wildlife Service. 1983-19. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates . U.S. Fish

How many fish? Comparison of two underwater visual sampling methods for monitoring fish communities

PubMed Central

Sini, Maria; Vatikiotis, Konstantinos; Katsoupis, Christos

2018-01-01

Background Underwater visual surveys (UVSs) for monitoring fish communities are preferred over fishing surveys in certain habitats, such as rocky or coral reefs and seagrass beds and are the standard monitoring tool in many cases, especially in protected areas. However, despite their wide application there are potential biases, mainly due to imperfect detectability and the behavioral responses of fish to the observers. Methods The performance of two methods of UVSs were compared to test whether they give similar results in terms of fish population density, occupancy, species richness, and community composition. Distance sampling (line transects) and plot sampling (strip transects) were conducted at 31 rocky reef sites in the Aegean Sea (Greece) using SCUBA diving. Results Line transects generated significantly higher values of occupancy, species richness, and total fish density compared to strip transects. For most species, density estimates differed significantly between the two sampling methods. For secretive species and species avoiding the observers, the line transect method yielded higher estimates, as it accounted for imperfect detectability and utilized a larger survey area compared to the strip transect method. On the other hand, large-scale spatial patterns of species composition were similar for both methods. Discussion Overall, both methods presented a number of advantages and limitations, which should be considered in survey design. Line transects appear to be more suitable for surveying secretive species, while strip transects should be preferred at high fish densities and for species of high mobility. PMID:29942703

VIS – A database on the distribution of fishes in inland and estuarine waters in Flanders, Belgium

PubMed Central

Brosens, Dimitri; Breine, Jan; Van Thuyne, Gerlinde; Belpaire, Claude; Desmet, Peter; Verreycken, Hugo

2015-01-01

Abstract The Research Institute for Nature and Forest (INBO) has been performing standardized fish stock assessments in Flanders, Belgium. This Flemish Fish Monitoring Network aims to assess fish populations in public waters at regular time intervals in both inland waters and estuaries. This monitoring was set up in support of the Water Framework Directive, the Habitat Directive, the Eel Regulation, the Red List of fishes, fish stock management, biodiversity research, and to assess the colonization and spreading of non-native fish species. The collected data are consolidated in the Fish Information System or VIS. From VIS, the occurrence data are now published at the INBO IPT as two datasets: ‘VIS - Fishes in inland waters in Flanders, Belgium’ and ‘VIS - Fishes in estuarine waters in Flanders, Belgium’. Together these datasets represent a complete overview of the distribution and abundance of fish species pertaining in Flanders from late 1992 to the end of 2012. This data paper discusses both datasets together, as both have a similar methodology and structure. The inland waters dataset contains over 350,000 fish observations, sampled between 1992 and 2012 from over 2,000 locations in inland rivers, streams, canals, and enclosed waters in Flanders. The dataset includes 64 fish species, as well as a number of non-target species (mainly crustaceans). The estuarine waters dataset contains over 44,000 fish observations, sampled between 1995 and 2012 from almost 50 locations in the estuaries of the rivers Yser and Scheldt (“Zeeschelde”), including two sampling sites in the Netherlands. The dataset includes 69 fish species and a number of non-target crustacean species. To foster broad and collaborative use, the data are dedicated to the public domain under a Creative Commons Zero waiver and reference the INBO norms for data use. PMID:25685001

Community structure and biogeography of shore fishes in the Gulf of Aqaba, Red Sea

NASA Astrophysics Data System (ADS)

Khalaf, Maroof A.; Kochzius, Marc

2002-02-01

Shore fish community structure off the Jordanian Red Sea coast was determined on fringing coral reefs and in a seagrass-dominated bay at 6 m and 12 m depths. A total of 198 fish species belonging to 121 genera and 43 families was recorded. Labridae and Pomacentridae dominated the ichthyofauna in terms of species richness and Pomacentridae were most abundant. Neither diversity nor species richness was correlated to depth. The abundance of fishes was higher at the deep reef slope, due to schooling planktivorous fishes. At 12 m depth abundance of fishes at the seagrass-dominated site was higher than on the coral reefs. Multivariate analysis demonstrated a strong influence on the fish assemblages by depth and benthic habitat. Fish species richness was positively correlated with hard substrate cover and habitat diversity. Abundance of corallivores was positively linked with live hard coral cover. The assemblages of fishes were different on the shallow reef slope, deep reef slope and seagrass meadows. An analysis of the fish fauna showed that the Gulf of Aqaba harbours a higher species richness than previously reported. The comparison with fish communities on other reefs around the Arabian Peninsula and Indian Ocean supported the recognition of an Arabian subprovince within the Indian Ocean. The affinity of the Arabian Gulf ichthyofauna to the Red Sea is not clear.

Seasonal dynamics in community structure, abundance, body size and sex ratio in two species of Neotropical annual fishes.

PubMed

Lanés, L E K; Godoy, R S; Maltchik, L; Polačik, M; Blažek, R; Vrtílek, M; Reichard, M

2016-11-01

Seven ephemeral pools on the coastal plain of southern Brazil were found to be inhabited by three annual and 22 non-annual fish species. Two common annual species (Austrolebias minuano and Cynopoecilus fulgens) exhibited clear seasonal dynamics, with the appearance of young fishes in the austral autumn (May to June) and a decline in abundance over the seasonal cycle. The third annual species, Austrolebias wolterstorffii, was rare. No seasonal dynamics were observed in non-annual fishes. The relative abundance of non-annual fishes compared with annual fishes increased over the seasonal cycle, but they coexisted widely. The size structure of annual fishes suggested the presence of a single age cohort in most pools though a second age cohort was registered in one pool in August, coinciding with a large flooding. Strong sexual dimorphism in body size was found in C. fulgens throughout the seasonal cycle, while no sexual dimorphism in body size was found in A. minuano. Female-biased sex ratios were recorded in both common annual fish species in the last three sampling dates (in spring), but not during the first two sampling dates (in winter). The natural lifespan of annual fishes was <8 months. Annual fishes disappeared before habitat desiccation in half of the pools, while non-annual fishes were still present. © 2016 The Fisheries Society of the British Isles.

Assemblages of fishes and their associations with environmental variables, lower San Joaquin River drainage, California

USGS Publications Warehouse

Brown, Larry R.

1998-01-01

Twenty sites in the lower San Joaquin River drainage, California, were sampled from 1993 to 1995 to characterize fish assemblages and their associations with measures of water quality and habitat quality. In addition, four fish community metrics were assessed, including percentages of native fish, omnivorous fish, fish intolerant of environmental degradation, and fish with external anomalies. Of the 31 taxa of fish captured during the study, only 10 taxa were native to the drainage. Multivariate analyses of percentage data identified four site groups characterized by characterized by different groups of species. The distributions of fish species were related to specific conductance, gradient, and mean depth; however, specific conductance acted as a surrogate variable for a large group of correlated variables. Two of the fish community metrics--percentage of introduced fish and percentage of intolerant fish--appeared to be responsive to environmental quality but the responses of the other two metrics--percentage of omnivorous fish and percentage of fish with anomalies--were less direct. The conclusion of the study is that fish assemblages are responsive to environmental conditions, including conditions associated with human-caused disturbances, particularly agriculture and water development. The results suggest that changes in water management and water quality could result in changes in species distributions. Balancing the costs and benefits of such changes poses a considerable challenge to resource managers. different groups of species.

Genetic calibration of species diversity among North America's freshwater fishes

PubMed Central

April, Julien; Mayden, Richard L.; Hanner, Robert H.; Bernatchez, Louis

2011-01-01

Freshwater ecosystems are being heavily exploited and degraded by human activities all over the world, including in North America, where fishes and fisheries are strongly affected. Despite centuries of taxonomic inquiry, problems inherent to species identification continue to hamper the conservation of North American freshwater fishes. Indeed, nearly 10% of species diversity is thought to remain undescribed. To provide an independent calibration of taxonomic uncertainty and to establish a more accessible molecular identification key for its application, we generated a standard reference library of mtDNA sequences (DNA barcodes) derived from expert-identified museum specimens for 752 North American freshwater fish species. This study demonstrates that 90% of known species can be delineated using barcodes. Moreover, it reveals numerous genetic discontinuities indicative of independently evolving lineages within described species, which points to the presence of morphologically cryptic diversity. From the 752 species analyzed, our survey flagged 138 named species that represent as many as 347 candidate species, which suggests a 28% increase in species diversity. In contrast, several species of parasitic and nonparasitic lampreys lack such discontinuity and may represent alternative life history strategies within single species. Therefore, it appears that the current North American freshwater fish taxonomy at the species level significantly conceals diversity in some groups, although artificially creating diversity in others. In addition to providing an easily accessible digital identification system, this study identifies 151 fish species for which taxonomic revision is required. PMID:21670289

Fishes of Missouri River, chute, and flood plain habitats: Chapter 4 in Initial biotic survey of Lisbon Bottom, Big Muddy National Fish and Wildlife Refuge

USGS Publications Warehouse

Grady, Joanne; Milligan, Jim; Chapman, Duane C.; Ehrhardt, Ellen A.; Dieterman, Douglas J.; Galat, David L.; Hooker, John; Kubisiak, John; DeLonay, Aaron; Little, Edward E.; Robinson, Jack; Tibbs, John

1999-01-01

The Lisbon Bottom Unit of the Big Muddy National Fish and Wildlife Refuge (Refuge) is approximately 2,200 acres and is the first complete unit of the Refuge. Primary objectives of the Refuge are to create and restore diverse riverine aquatic habitats and reconnect the Missouri River to its flood plain where feasible. Management seeks to accomplish these objectives by encouraging natural processes of erosion, deposition, and succession to the greatest extent possible.One of the most salient aquatic features of the Lisbon Bottom Unit is a newly created 2-mile-long free-flowing chute, or side channel (Fig. 1). This chute began forming as a levee breech scour hole during the Great Flood of 1993. The chute continued to develop during the 1995 flood and finally cut through to a flowing side channel during the 1996 flood. Extensive erosion and bank sluffing continued during 1997 due to sustained high flows that occurred throughout most of the year. The chute has progressively become wider and deeper with a developing meander pattern and channel bars have begun to form. Lisbon Bottom also contains several seasonal and permanent wetlands and is subject to periodic flooding at high Missouri River stages.Eight studies have been completed or are ongoing to evaluate Missouri River fishes associated with various habitat components of Lisbon Bottom and adjacent Missouri River reaches (Table 1). Several are part of much larger investigations to evaluate fish use of flood-created habitat features, basinwide fish assessment, and endangered or candidate species concerns.At the Lisbon Bottom Unit or in the Missouri River adjacent to the unit 54 fish species were collected (Table 2). Eight of these species have either a protected status under State or Federal laws or biologists consider them to potentially qualify for protected status. The status of the following fish is listed in Table 2: pallid sturgeon x shovelnose sturgeon hybrid, paddlefish, northern pike, sturgeon chub, sicklefin chub, ghost shiner, western silvery minnow, plains minnow, and blue sucker. Equally important to note are fish species that were not collected. The flathead chub, currently listed as State endangered and proposed for Federal listing, were not collected in any of the studies.Common fish species, collected in all seven sampling studies, included gizzard shad, common carp, river carpsucker, and freshwater drum. Paddlefish, skipjack herring, silver carp, white sucker, redfin shiner, western silvery minnow, bullhead minnow, and black bullhead were each collected in only one of the seven studies.Pflieger (1971) developed a guild system for the fishes of Missouri based on distribution patterns and centers of abundance. Fish were assigned to one of four primary faunal groups: Ozark, Big River, Lowland, and Prairie. Two secondary groups (Ozark-prairie and Ozark-lowland) were defined for species equally abundant and distributed in two of the primary areas. Two Ozark-prairie species, shorthead redhorse and white sucker, were collected on or near the Lisbon Bottom Unit.Big River species are found primarily in the Missouri and Mississippi Rivers. The environmental factors controlling fish distribution in these rivers appear to be substrate, current velocity, and turbidity. On or near the Lisbon Bottom Unit 18 Big River species were collected (Table 2).Lowland species are intolerant of siltation and high turbidity. They inhabit standing or slow-moving water with sand, fine gravel, and organic debris substrates. Two Lowland species, bullhead minnow and mosquitofish, were collected in connected scours on the Lisbon Bottom Unit.Prairie species have broader ecological tolerances than the Ozark and Lowland species. They are largely absent in high gradient streams and cool, clear waters. Prairie species make up a significant proportion of Missouri and Mississippi River fishes. Seven Prairie species were collected on or near the Lisbon Bottom Unit (Table 2).The last group, Wide-ranging, was defined as the species more widespread than the other faunal groups with broader environmental tolerances. Most Wide-ranging species occur at least occasionally in all sections of the state. Nineteen Wide-ranging species were collected on or near the Lisbon Bottom Unit (Table 2).Kubisiak (1997) found that isolated scours in the Lower Missouri River were dominated by Wide-ranging species. Connected scours also held Wideranging species but they contained Prairie species and were dominated by Big River species. Faunal group diversity and species richness were compared between isolated (Study l) and connected (Studies 4, 5, 7, and 8) scours of the Lisbon Bottom Unit. Species richness was similar with 22 species collected in isolated scours and an average of 24.8 species collected in connected scours. Isolated scour fish catches were dominated by Wide-ranging fish (59%) with 14% Big River fishes and 14% Prairie fishes. Connected scours had a larger percentage of Big River fish (32%) and fewer Wide-ranging (36%) and Prairie (13%) species than the isolated scours. In the combined studies, Wide-ranging fish dominated the connected scours.A similar comparison was made of fish from chute habitats and the Missouri River. Chute habitats include the Lisbon Bottom Chute, the chute between the right bank and island located at river mile 219, and a shallow channel running between a large sandbar complex and the channel border adjacent to Lisbon Bottom. Species richness in the chutes (35 species) was greater than that of the adjacent river (23 species). Big River species (40%) dominated the chute samples, followed by Wide-ranging at 31% Cand Prairie Cut 14%.The river samples contained equal numbers of Wide-ranging species (35%) and Big River species (35%) with 17% Prairie species. Differences in fish guild diversity and species richness may be due to numerous factors including sampling effort and sampling season. River samples were collected only in Study 3 in October; chute samples were collected in July, August, and October. Fish may have been using the chute in July and August to spawn, feed, or escape high river levels.The Lisbon Bottom Chute is a truly unique feature of the Lower Missouri River. It is the first naturally created side channel to develop since the U.S. Army Corps of Engineers tamed the river. The Corps eliminated 89% of the islands in the Missouri River between 1879 and 1954 (Funk and Robinson 1974). The chutes between the islands and the shore were shallower with less current than the main channel. These areas provided diversity to the Missouri River fish habitat, serving as nursery and feeding areas. The Lisbon Bottom Unit of the Big Muddy National Fish and Wildlife Refuge will continue to be studied in an effort to understand the complex role these areas play in river systems.

Fish species of greatest conservation need in wadeable Iowa streams: current status and effectiveness of Aquatic Gap Program distribution models

USGS Publications Warehouse

Sindt, Anthony R.; Pierce, Clay; Quist, Michael C.

2012-01-01

Effective conservation of fish species of greatest conservation need (SGCN) requires an understanding of species–habitat relationships and distributional trends. Thus, modeling the distribution of fish species across large spatial scales may be a valuable tool for conservation planning. Our goals were to evaluate the status of 10 fish SGCN in wadeable Iowa streams and to test the effectiveness of Iowa Aquatic Gap Analysis Project (IAGAP) species distribution models. We sampled fish assemblages from 86 wadeable stream segments in the Mississippi River drainage of Iowa during 2009 and 2010 to provide contemporary, independent fish species presence–absence data. The frequencies of occurrence in stream segments where species were historically documented varied from 0.0% for redfin shiner Lythrurus umbratilis to 100.0% for American brook lampreyLampetra appendix, with a mean of 53.0%, suggesting that the status of Iowa fish SGCN is highly variable. Cohen's kappa values and other model performance measures were calculated by comparing field-collected presence–absence data with IAGAP model–predicted presences and absences for 12 fish SGCN. Kappa values varied from 0.00 to 0.50, with a mean of 0.15. The models only predicted the occurrences of banded darterEtheostoma zonale, southern redbelly dace Phoxinus erythrogaster, and longnose daceRhinichthys cataractae more accurately than would be expected by chance. Overall, the accuracy of the twelve models was low, with a mean correct classification rate of 58.3%. Poor model performance probably reflects the difficulties associated with modeling the distribution of rare species and the inability of the large-scale habitat variables used in IAGAP models to explain the variation in fish species occurrences. Our results highlight the importance of quantifying the confidence in species distribution model predictions with an independent data set and the need for long-term monitoring to better understand the distributional trends and habitat associations of fish SGCN.

Are vegetated areas of mangroves attractive to juvenile and small fish? The case of Dongzhaigang Bay, Hainan Island, China

NASA Astrophysics Data System (ADS)

Wang, Mao; Huang, Zhenyuan; Shi, Fushan; Wang, Wenqing

2009-11-01

Well-developed aerial roots of mangroves make it difficult to study how fish utilize the mangrove forest as a habitat. In the present study, we compared the differences in fish assemblages in three major types of habitats of mangrove estuary (vegetated area, treeless mudflat, and creek) of a mangrove bay in Hainan Island, China, at different seasons during two consecutive years. Three types of gears, centipede net, gill net and cast net, were used in the different habitats of mangrove estuary and sampling efficiencies among gears were evaluated. Centipede nets were used in all the three types of habitats and cast nets and gill nets in treeless mudflats and creeks. Fish assemblages were dependent on gears used. Centipede net could efficiently catch fish occurring both inside and outside of vegetated areas efficiently. A total of 115 fish species in 51 families were collected. In terms of numbers of species per family, Gobiidae was the most diverse (17 species), followed by Mugilidae (5 species). Almost all of the fish were juvenile or small fish and few predators were recorded, implying low predation pressure in the bay. ANOVA analysis showed that significant seasonal and spatial variation existed in species richness, abundance, and biomass, which were less in the vegetated areas than those of treeless mudflats and creeks. The attraction of vegetated areas to fish was less than that of creeks and mudflats. Many species were specific to a particular habitat type, 4 species occurring exclusively in the creeks, 45 species occurring exclusively in the treeless mudflats, and 5 species occurring exclusively in the vegetated areas. The results indicated that mangrove estuaries were potentially attractive habitats for juvenile and small fish, but this attraction was accomplished by a connection of vegetated areas, treeless mudflats and creeks, not only by vegetated areas.

[Species composition, diversity and density of small fishes in two different habitats in Niushan Lake].

PubMed

Ye, Shao-Wen; Li, Zhong-Jie; Cao, Wen-Xuan

2007-07-01

This paper studied the spatial distribution of small fishes in a shallow macrophytic lake, Niushan Lake in spring 2003, and its relations with habitat heterogeneity. Based on the macrophyte cover condition, distance from lake shore and water depth, two representative habitat types in the lake were selected. Habitat A was near the shore with dense submersed macrophyte, while habitat B was far from the shore with sparse submersed macrophyte. Small fishes were sampled quantitatively by block net (180 m2), and their densities within the net area were estimated by multiple mark-recapture or Zippin's removal method. The results showed that there were some differences in species composition, biodiversity measurement, and estimated density of small fishes between the two habitats: 1) the catches in habitat A consisted of 14 small fish species from 5 families, among which, benthopelagic species Rhodeus ocellatus, Paracheilognathus imberbis and Pseudorasbora parva were considered as dominant species, while those in habitat B consisted of 9 small fish species from 3 families, among which, bottom species Rhinogobius giurinus and Micropercops swinhonis were dominant; 2) the Bray-Curtis index between the two small fish communities was 0.222, reflecting their low structure similarity, and no significant difference was observed between their rank/ abundance distributions, both of which belonged to log series distribution; 3) the total density of 9 major species in habitat A was 8.71 ind x m(-2), while that of 5 major species in habitat B was only 3.54 ind x m(-2). The fact that the spatial distribution of the small fishes differed with habitats might be related to their habitat need for escaping predators, feeding, and breeding, and thus, aquatic macrophyte habitat should be of significance in the rational exploitation of small fish resources as well as the conservation of fish resource diversity.

Experimental infection of several fish species with the causative agent of Kuchijirosho (snout ulcer disease) derived from the tiger puffer Takifugu rubripes.

PubMed

Miyadai, T; Kitamura, S I; Uwaoku, H; Tahara, D

2001-12-05

Kuchijirosho (snout ulcer disease) is a fatal epidemic disease which affects the tiger puffer, Takifugu rubripes, a commercial fish species in Japan and Korea. To assess the possibility that non-tiger puffer fish can serve as reservoirs of infection, 5 fish species were challenged by infection with the extracts of Kuchijirosho-affected brains from cultured tiger puffer: grass puffer T. niphobles, fine-patterned puffer T. poecilonotus, panther puffer T. pardalis, red sea bream Pagrus major, and black rockfish Sebastes schlegeli. When slightly irritated, all these species, especially the puffer fish, exhibited typical signs of Kuchijirosho, i.e., erratic swimming, biting together and bellying out (swelling of belly), as generally observed in tiger puffers affected by Kuchijirosho. Although the mortalities of the 2 non-puffer species were lower, injection of the extracts prepared from the brains of both inoculated fish into tiger puffer resulted in death, indicating that the inoculated fish used in this experiment have the potential to be infected with the Kuchijirosho agent. Condensations of nuclei or chromatin in the large nerve cells, which is a major characteristic of Kuchijirosho, were histopathologically observed to some extent in the brains of all kinds of puffer fish species infected. These findings suggest that the virus can spread horizontally among wild and cultured puffers and even among fishes belonging to different orders.

DISTRIBUTIONS OF LAKE FISHES OF THE NORTHEAST USA--III. SALMONIDAE AND ASSOCIATED COLDWATER SPECIES

EPA Science Inventory

We present distributional maps and discuss native status for fish species characteristic of coldwater lakes, sampled from 203 randomly selected lakes in the northeastern USA (New England, New York, New Jersey). Eleven coldwater fish species from four families (Salmonidae, Osmeri...

78 FR 23222 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-18

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC630 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: NOAA's National Marine Fisheries Service (NMFS... CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in This Notice This...

75 FR 33243 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-11

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 6048-XW87 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: NOAA's National Marine Fisheries Service (NMFS... NMFS regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in...

Endangered Fish Species in Kansas: Historic vs Contemporary Distribution

EPA Science Inventory

Background/Question/Methods Kansas state has more freshwater fish species than other states in the west and northern US. Based on recent count, more than 140 fishes have been documented in Kansas rivers. And at least five are categorized as endangered species in Kansas (and thre...

Status and historical changes in the fish community in Erhai Lake

NASA Astrophysics Data System (ADS)

Tang, Jianfeng; Ye, Shaowen; Li, Wei; Liu, Jiashou; Zhang, Tanglin; Guo, Zhiqiang; Zhu, Fengyue; Li, Zhongjie

2013-07-01

Erhai Lake is the second largest freshwater lake on the Yunnan Plateau, Southwest China. In recent decades, a number of exotic fish species have been introduced into the lake and the fish community has changed considerably. We evaluated the status of the fish community based on surveys with multimesh gillnet, trap net, and benthic fyke-net between May 2009 and April 2012. In addition, we evaluated the change in the community using historical data (1952-2010) describing the fish community and fishery harvest. The current fish community is dominated by small-sized fishes, including Pseudorasbora parva, Rhinogobius giurinus, Micropercops swinhonis, Hemiculter leucisculus, and Rhinogobius cliffordpopei. These accounted for 87.7% of the 22 546 total specimens collected. Omnivorous and carnivorous species dominated the community. A canonical correspondence analysis (CCA) plot revealed that the distribution of fishes in the lake is influenced by aquatic plants, water temperature, pH, and season. The abundance of indigenous species has declined sharply, and a majority of endemic species have been extirpated from the lake (a decrease from seven to two species). In contrast, the number of exotic species has increased since the 1960s to a total of 22 at present. The fishery harvest decreased initially following the 1960s, but has since increased due to the introduction of non-native fish and stocking of native fish. The fishery harvest was significantly correlated with total nitrogen, not total phosphorus, during the past 20 years. Based on our results, we discuss recommendations for the restoration and conservation of the fish resources in Erhai Lake.

Heavy metals in wild marine fish from South China Sea: levels, tissue- and species-specific accumulation and potential risk to humans.

PubMed

Liu, Jin-Ling; Xu, Xiang-Rong; Ding, Zhen-Hua; Peng, Jia-Xi; Jin, Ming-Hua; Wang, You-Shao; Hong, Yi-Guo; Yue, Wei-Zhong

2015-10-01

Heavy metal pollution in marine fish has become an important worldwide concern, not only because of the threat to fish in general, but also due to human health risks associated with fish consumption. To investigate the occurrence of heavy metals in marine fish species from the South China Sea, 14 fish species were collected along the coastline of Hainan China during the spring of 2012 and examined for species- and tissue-specific accumulation. The median concentrations of Cd, Cr, Cu, Zn, Pb and As in muscle tissue of the examined fish species were not detectable (ND), 2.02, 0.24, 2.64, 0.025, and 1.13 mg kg(-1) wet weight, respectively. Levels of Cu, Zn, Cd and Cr were found to be higher in the liver and gills than in muscle, while Pb was preferentially accumulated in the gills. Differing from other heavy metals, As did not exhibit tissue-specific accumulation. Inter-species differences of heavy metal accumulation were attributed to the different habitat and diet characteristics of marine fish. Human dietary exposure assessment suggested that the amounts of both Cr and As in marine wild fish collected from the sites around Hainan, China were not compliant with the safety standard of less than 79.2 g d(-1) for wild marine fish set by the Joint FAO/WHO Expert Committee on Food Additives. Further research to identify the explicit sources of Cr and As in marine fish from South China Sea should be established.

Role of the fish astyanax aeneus (Characidae) as a keystone nutrient recycler in low-nutrient neotropical streams

USGS Publications Warehouse

Small, G.E.; Pringle, C.M.; Pyron, M.; Duff, J.H.

2011-01-01

Nutrient recycling by animals is a potentially important biogeochemical process in both terrestrial and aquatic ecosystems. Stoichiometric traits of individual species may result in some taxa playing disproportionately important roles in the recycling of nutrients relative to their biomass, acting as keystone nutrient recyclers. We examined factors controlling the relative contribution of 12 Neotropical fish species to nutrient recycling in four streams spanning a range of phosphorus (P) levels. In high-P conditions (135 ??g/L soluble reactive phosphorus, SRP), most species fed on P-enriched diets and P excretion rates were high across species. In low-P conditions (3 ??g/L SRP), aquatic food resources were depleted in P, and species with higher body P content showed low rates of P recycling. However, fishes that were subsidized by terrestrial inputs were decoupled from aquatic P availability and therefore excreted P at disproportionately high rates. One of these species, Astyanax aeneus (Characidae), represented 12% of the total population and 18% of the total biomass of the fish assemblage in our focal low-P study stream but had P excretion rates >10-fold higher than other abundant fishes. As a result, we estimated that P excretion by A. aeneus accounted for 90% of the P recycled by this fish assemblage and also supplied ???90% of the stream P demand in this P-limited ecosystem. Nitrogen excretion rates showed little variation among species, and the contribution of a given species to ecosystem N recycling was largely dependent upon the total biomass of that species. Because of the high variability in P excretion rates among fish species, ecosystem-level P recycling could be particularly sensitive to changes in fish community structure in P-limited systems. ?? 2011 by the Ecological Society of America.

Thermal affinity as the dominant factor changing Mediterranean fish abundances.

PubMed

Givan, Or; Edelist, Dor; Sonin, Oren; Belmaker, Jonathan

2018-01-01

Recent decades have seen profound changes in species abundance and community composition. In the marine environment, the major anthropogenic drivers of change comprise exploitation, invasion by nonindigenous species, and climate change. However, the magnitude of these stressors has been widely debated and we lack empirical estimates of their relative importance. In this study, we focused on Eastern Mediterranean, a region exposed to an invasion of species of Red Sea origin, extreme climate change, and high fishing pressure. We estimated changes in fish abundance using two fish trawl surveys spanning a 20-year period, and correlated these changes with estimated sensitivity of species to the different stressors. We estimated sensitivity to invasion using the trait similarity between indigenous and nonindigenous species; sensitivity to fishing using a published composite index based on the species' life-history; and sensitivity to climate change using species climatic affinity based on occurrence data. Using both a meta-analytical method and random forest analysis, we found that for shallow-water species the most important driver of population size changes is sensitivity to climate change. Species with an affinity to warm climates increased in relative abundance and species with an affinity to cold climates decreased suggesting a strong response to warming local sea temperatures over recent decades. This decrease in the abundance of cold-water-associated species at the trailing "warm" end of their distribution has been rarely documented. Despite the immense biomass of nonindigenous species and the presumed high fishing pressure, these two latter factors seem to have only a minor role in explaining abundance changes. The decline in abundance of indigenous species of cold-water origin indicates a future major restructuring of fish communities in the Mediterranean in response to the ongoing warming, with unknown impacts on ecosystem function. © 2017 John Wiley & Sons Ltd.

Isotopic niches of fishes in coastal, neritic and oceanic waters off Adélie land, Antarctica

NASA Astrophysics Data System (ADS)

Cherel, Yves; Koubbi, Philippe; Giraldo, Carolina; Penot, Florian; Tavernier, Eric; Moteki, Masato; Ozouf-Costaz, Catherine; Causse, Romain; Chartier, Amélie; Hosie, Graham

2011-08-01

We used the stable isotope method to investigate the ecological niches of Antarctic fishes, with δ 13C and δ 15N as proxies of fish habitats and dietary habits, respectively. Muscle isotopic signature was measured for each of 237 delipidated tissue samples from 27 fish species collected offshore Adélie Land, East Antarctica. Overall, δ 13C values ranged from -25.3‰ to -18.2‰, thus allowing characterizing of the fish habitats, with inshore/benthic species having more positive δ 13C signatures than offshore/pelagic ones. No clear difference in the δ 13C values of pelagic fishes was found between species living in neritic and oceanic waters. Overall, the δ 15N signatures of neritic pelagic and epibenthic fishes encompassed ˜1.0 trophic level (3.1‰), a higher difference than that (1.4‰) found within the oceanic assemblage. Fishes with the lowest and highest δ 15N values are primarily invertebrate- and fish-eaters, respectively. The isotopic niches of fishes illustrate the different mechanisms allowing coexistence, with most fishes segregating at least by one of the two niche axes (δ 13C and δ 15N). Muscle isotopic values also document interindividual foraging specialization over the long-term in coastal benthic fishes, but not in more offshore pelagic species. Finally, the δ 15N signatures of fishes overlap with those of penguins and seals, indicating that seabirds and marine mammals share the upper levels of the Antarctic pelagic ecosystem with some large fish species. In conclusion, the concept of isotopic niche is a powerful tool to investigate various aspects of the ecological niche of Antarctic fishes, thus complementing the use of other conventional and non-conventional approaches.

The Importance of the Regional Species Pool, Ecological Species Traits and Local Habitat Conditions for the Colonization of Restored River Reaches by Fish

PubMed Central

Stoll, Stefan; Kail, Jochem; Lorenz, Armin W.; Sundermann, Andrea; Haase, Peter

2014-01-01

It is commonly assumed that the colonization of restored river reaches by fish depends on the regional species pools; however, quantifications of the relationship between the composition of the regional species pool and restoration outcome are lacking. We analyzed data from 18 German river restoration projects and adjacent river reaches constituting the regional species pools of the restored reaches. We found that the ability of statistical models to describe the fish assemblages established in the restored reaches was greater when these models were based on ‘biotic’ variables relating to the regional species pool and the ecological traits of species rather than on ‘abiotic’ variables relating to the hydromorphological habitat structure of the restored habitats and descriptors of the restoration projects. For species presence in restored reaches, ‘biotic’ variables explained 34% of variability, with the occurrence rate of a species in the regional species pool being the most important variable, while ’abiotic’ variables explained only the negligible amount of 2% of variability. For fish density in restored reaches, about twice the amount of variability was explained by ‘biotic’ (38%) compared to ‘abiotic’ (21%) variables, with species density in the regional species pool being most important. These results indicate that the colonization of restored river reaches by fish is largely determined by the assemblages in the surrounding species pool. Knowledge of species presence and abundance in the regional species pool can be used to estimate the likelihood of fish species becoming established in restored reaches. PMID:24404187

Hybrid seine for full fish community collections

USGS Publications Warehouse

McKenna, James E.; Waldt, Emily M.; Abbett, Ross; David, Anthony; Snyder, James

2013-01-01

Seines are simple and effective fish collection gears, but the net mesh size influences how well the catch represents the fish communities. We designed and tested a hybrid seine with a dual-mesh bag (1/4″ and 1/8″) and compared the fish assemblage collected by each mesh. The fine-mesh net retained three times as many fish and collected more species (as many as eight), including representatives of several rare species, than did the coarser mesh. The dual-mesh bag permitted us to compare both sizes and species retained by each layer and to develop species-specific abundance correction factors, which allowed comparison of catches with the coarse-mesh seine used for earlier collections. The results indicate that a hybrid seine with coarse-mesh wings and a fine-mesh bag would enhance future studies of fish communities, especially when small-bodied fishes or early life stages are the research focus.

Biological and communication skills needed for introduced fish biologists

USGS Publications Warehouse

Bonar, Scott A.

2016-01-01

What skills and knowledge will a new graduate seeking employment need to work with introduced fishes? Clearly, success in introduced species management—similar to other disciplines in fisheries—requires a mixture of scientific and communication skills. However, specific abilities especially important to a biologist who manages introduced fishes should be highlighted. Unlike most other management strategies, stocking an introduced species can result in unintended and irreversible impacts, so particular care must be employed when stocking is considered. Furthermore, fish populations in areas outside of the introduced species management area might also be affected, usually negatively, if the introduced fish escapes. Therefore, rock-solid knowledge of basic aquatic ecology, including risk management; fish taxonomy (so the wrong fish species is not mistakenly stocked!); familiarity with human values of both the time and the place (which requires communication skills); and a strong understanding of human history are all important.

77 FR 51520 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-24

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... (16 U.S.C. 1531-1543) and regulations governing listed fish and wildlife permits (50 CFR parts 222-226... expect to kill any listed fish but a small number, up to 20 percent (equivalent to one fish), may die as...

Life history strategies of fish species and biodiversity in eastern USA streams

USGS Publications Warehouse

Meador, Michael R.; Brown, Larry M.

2015-01-01

Predictive models have been used to determine fish species that occur less frequently than expected (decreasers) and those that occur more frequently than expected (increasers) in streams in the eastern U.S. Coupling life history traits with 51 decreaser and 38 increaser fish species provided the opportunity to examine potential mechanisms associated with predicted changes in fish species distributions in eastern streams. We assigned six life history traits – fecundity, longevity, maturation age, maximum total length, parental care, and spawning season duration – to each fish species. Decreaser species were significantly smaller in size and shorter-lived with reduced fecundity and shorter spawning seasons compared to increaser species. Cluster analysis of traits revealed correspondence with a life history model defining equilibrium (low fecundity, high parental care), opportunistic (early maturation, low parental care), and periodic (late maturation, high fecundity, low parental care) end-point strategies. Nearly 50 % of decreaser species were associated with an intermediate opportunistic-periodic strategy, suggesting that abiotic factors such as habitat specialization and streamflow alteration may serve as important influences on life history traits and strategies of decreaser species. In contrast, the percent of increaser species among life history strategy groups ranged from 21 to 32 %, suggesting that life history strategies of increaser species were more diverse than those of decreaser species. This study highlights the utility of linking life history theory to biodiversity to better understand mechanisms that contribute to fish species distributions in the eastern U.S.

Vertebrate diets derived from trophically transmitted fish parasites in the Bothnian Bay.

PubMed

Valtonen, E T; Marcogliese, David J; Julkunen, Markku

2010-01-01

Parasites that are transmitted through predator-prey interactions may be used as indicators of trophic relationships between organisms. Yet, they are rarely used as such in the construction of topological (predator-prey) food webs. We constructed food webs of vertebrate trophic interactions using observed diet alone, trophically transmitted parasites alone, and the combination of the two based on data from 31 species of fish from the Bothnian Bay, Finland. The fish food web contained 530 links derived from observed diet, 724 links inferred from parasitism, and 1,058 links calculated from a combination of both stomach contents and parasites. This sub-web constructed from stomach contents had a mean of 17.1 links per fish species, while that using parasites had 23.4 links per fish. Combining the two diet indicators yielded 34.1 links per fish species, illustrating the complementarity of the two methods. Mean number of prey species per fish species was 12.5 using observed diet items, 15.8 using parasites, and 24.5 using both measures together. Mean number of predators per fish species was 7.4 using observed diet, 11.7 using parasites and 15.0 using both. A positive correlation was found between the mean number of parasites and the number of prey taxa in the diet among the fishes. Omnivorous fish had the highest diversity of both parasite species and prey items, while benthophagous fish had among the lowest. Mean total abundance and mean total prevalence of parasites correlated positively with fish size, with piscivores being the largest with the highest abundance and prevalence, while planktivores and benthivores had the lowest. Trophically transmitted parasites may be used to help construct vertebrate sub-webs and derive information about food web processes. Parasites alone provided equivalent if not more information than observed diet. However, resolution is improved by using parasites and observed diet together.

76 FR 2664 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-14

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS...) and 14092 (applicant: California Department of Fish and Game). In that notice, the permit application... American green sturgeon associated with conducting surveys measuring fish response to initial and...

Ingestion of microplastics by commercial fish off the Portuguese coast.

PubMed

Neves, Diogo; Sobral, Paula; Ferreira, Joana Lia; Pereira, Tânia

2015-12-15

The digestive tract contents of 263 individuals from 26 species of commercial fish were examined for microplastics. These were found in 17 species, corresponding to 19.8% of the fish of which 32.7% had ingested more than one microplastic. Of all the fish that ingested microplastics, 63.5% was benthic and 36.5% pelagic species. A total of 73 microplastics were recorded, 48 (65.8%) being fibres and 25 (34.2%) being fragments. Polymers were polypropylene, polyethylene, alkyd resin, rayon, polyester, nylon and acrylic. The mean of ingested microplastics was 0.27 ± 0.63 per fish, (n=263). Pelagic fish ingested more particles and benthic fish ingested more fibres, but no significant differences were found. Fish with the highest number of microplastics were from the mouth of the Tagus river. Scomber japonicus registered the highest mean of ingested microplastics, suggesting its potential as indicator species to monitor and investigate trends in ingested litter, in the MSFD marine regions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Widespread microplastic ingestion by fish assemblages in tropical estuaries subjected to anthropogenic pressures.

PubMed

Vendel, A L; Bessa, F; Alves, V E N; Amorim, A L A; Patrício, J; Palma, A R T

2017-04-15

Our aim was to quantify microplastic ingestion by fish assemblages in two tropical Brazilian estuaries and to evaluate whether biological and ecological factors influence the ingestion of microplastics by fish species. Of 2233 fish from both estuaries (from 69 species) examined in this study, 9% of the individuals (24 species) had microplastics in their gut contents. Microplastic ingestion occurred irrespective of fish size and functional group. The diet of fish species was analyzed based on prey items identified in the fish's full stomach contents and five feeding guilds were defined. Microplastics were common throughout all feeding guilds. Low (average ingestion values 1.06±0.30 items/total fish) but widespread occurrence among estuaries also indicates proliferation of microplastic pollution. Our findings highlight the need to focus on assemblage level studies to understand the real magnitude of the problem and emphasize the urgency of mitigation measures directed at microplastic pollution in estuarine ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of fish assemblages and population structure of freshwater fish in two Tunisian reservoirs: implications for fishery management.

PubMed

Mili, Sami; Ennouri, Rym; Dhib, Amel; Laouar, Houcine; Missaoui, Hechmi; Aleya, Lotfi

2016-06-01

To monitor and assess the state of Tunisian freshwater fisheries, two surveys were undertaken at Ghezala and Lahjar reservoirs. Samples were taken in April and May 2013, a period when the fish catchability is high. The selected reservoirs have different surface areas and bathymetries. Using multi-mesh gill nets (EN 14575 amended) designed for sampling fish in lakes, standard fishing methods were applied to estimate species composition, abundance, biomass, and size distribution. Four species were caught in the two reservoirs: barbel, mullet, pike-perch, and roach. Fish abundance showed significant change according to sampling sites, depth strata, and the different mesh sizes used. From the reservoir to the tributary, it was concluded that fish biomass distribution was governed by depth and was most abundant in the upper water layers. Species size distribution differed significantly between the two reservoirs, exceeding the length at first maturity. Species composition and abundance were greater in Lahjar reservoir than in Ghezala. Both reservoirs require support actions to improve fish productivity.

50 CFR 270.3 - Submission of application.

Code of Federal Regulations, 2010 CFR

2010-10-01

... ADMINISTRATION, DEPARTMENT OF COMMERCE FISH AND SEAFOOD PROMOTION SPECIES-SPECIFIC SEAFOOD MARKETING COUNCILS... Marketing Council for one or more species of fish and fish products of that species. One signed original and... implement marketing and promotion plans under the Act. (The American Fisheries Society's “List of Common and...

Distribution of nekton species and abundance within and among four Oregon estuaries

EPA Science Inventory

Crabs, shrimps and fishes provide valued ecosystem goods and services to communities of the Pacific Northwest, including species that are fished for food and recreation and those that serve as prey for fished species. In the face of increasing use of these services and potential...

DNA barcoding reveals high levels of genetic diversity in the fishes of the Itapecuru Basin in Maranhão, Brazil.

PubMed

Nascimento, M H S; Almeida, M S; Veira, M N S; Limeira Filho, D; Lima, R C; Barros, M C; Fraga, E C

2016-08-29

DNA barcoding is a useful complementary tool for use in traditional taxonomic studies due to its ability to detect cryptic species, and may be particularly efficient in the identification of fish species. The fish fauna of the Itapecuru River represents an important fishery resource in the Brazilian State of Maranhão, although it is currently suffering increasing degradation as a result of anthropogenic impacts. Therefore, DNA barcoding was used in the present study to identify fish species and establish a database of the rich freshwater fish fauna of Maranhão. A total of 440 specimens were analyzed, corresponding to 64 species belonging to 59 genera, 31 families, and 10 orders. Overall, 92.19% of these species could be identified by DNA barcoding, and were characterized by low levels (average 0.80%) of intra-specific divergence. However, five species (Anableps anableps, Gymnotus carapo, Sciades couma, Pseudauchenipterus nodosus, and Leporinus piau) presented values of mean genetic divergence above 3%, indicating the existence of cryptic diversity in these fishes. The DNA barcoding approach permitted the analysis of a large number of specimens and facilitated the discrimination and identification of closely related fish species in the Itapecuru Basin.

Observations of the distributions of five fish species in a small Appalachian stream

USGS Publications Warehouse

Larson, Gary L.; Hoffman, Robert L.; Moore, S.E.

2002-01-01

The notion has been growing that resident stream fishes exhibit a greater capacity for movement than was previously thought. In this study, we recorded the distributions of four resident fish species (longnose dace Rhinichthys cataractae, blacknose dace R. atratulus, mottled sculpin Cottus bairdi, and rainbow trout Oncorhynchus mykiss) and one nonresident species (central stoneroller Campostoma anomalum) in Rock Creek, a small tributary of Cosby Creek in Great Smoky Mountains National Park, over the period 1979a??1995. During this study, 1,998 individuals of resident species were collected from stream sections considered to be within a common area of distribution for each species. Forty-five individuals of resident and nonresident species were captured upstream of these areas, and eight of these fish were considered to be larger than individuals considered typical for each species. Small mammal dispersal theory concepts were used to classify and describe fish movements outside of common areas of distribution. These movements were identified as important in maintaining population connectivity within stream drainages, contributing to reducing the potential for local extinctions of populations and to the recolonization of unoccupied habitats. This study highlights the need for continued study of fish movements in stream drainages and for development of appropriate resource management strategies based partly on the spatial dynamics of fish populations and communities.

Quantitative species-level ecology of reef fish larvae via metabarcoding.

PubMed

Kimmerling, Naama; Zuqert, Omer; Amitai, Gil; Gurevich, Tamara; Armoza-Zvuloni, Rachel; Kolesnikov, Irina; Berenshtein, Igal; Melamed, Sarah; Gilad, Shlomit; Benjamin, Sima; Rivlin, Asaph; Ohavia, Moti; Paris, Claire B; Holzman, Roi; Kiflawi, Moshe; Sorek, Rotem

2018-02-01

The larval pool of coral reef fish has a crucial role in the dynamics of adult fish populations. However, large-scale species-level monitoring of species-rich larval pools has been technically impractical. Here, we use high-throughput metabarcoding to study larval ecology in the Gulf of Aqaba, a region that is inhabited by >500 reef fish species. We analysed 9,933 larvae from 383 samples that were stratified over sites, depth and time. Metagenomic DNA extracted from pooled larvae was matched to a mitochondrial cytochrome c oxidase subunit I barcode database compiled for 77% of known fish species within this region. This yielded species-level reconstruction of the larval community, allowing robust estimation of larval spatio-temporal distributions. We found significant correlations between species abundance in the larval pool and in local adult assemblages, suggesting a major role for larval supply in determining local adult densities. We documented larval flux of species whose adults were never documented in the region, suggesting environmental filtering as the reason for the absence of these species. Larvae of several deep-sea fishes were found in shallow waters, supporting their dispersal over shallow bathymetries, potentially allowing Lessepsian migration into the Mediterranean Sea. Our method is applicable to any larval community and could assist coral reef conservation and fishery management efforts.

New records of sea lice (Copepoda: Caligidae) from marine fishes in Jaramijó, an area with potential for sea-cage aquaculture in Ecuador.

PubMed

Morales-Serna, Francisco Neptali; Caña-Bozada, Víctor; Mera-Loor, Geormery; Loor-Andrade, Peggy; Fajer-Ávila, Emma J; Ho, Ju-Shey

2015-02-20

Farming of finfish in sea cages is gaining popularity worldwide. These systems are a suitable environment for the emergence, establishment and transmission of parasites or pathogens, such as sea lice (Copepoda: Caligidae), known to cause serious diseases and economic losses in finfish aquaculture worldwide. In coastal waters of Jaramijó, Ecuador, there are plans to culture spotted rose snapper (Lutjanus guttatus) and longfin yellowtail (Seriola rivoliana); however, the information about the occurrence of sea lice on fish from this country is scarce. To address this problem, a parasitological survey of economically important fish caught by artisanal fishermen was conducted between June 2013 and May 2014. A total of 608 fish belonging to 66 species were examined. Sea lice were found on 23 fish species. The diversity of these parasites consisted of 22 species of Caligus and 5 species of Lepeophtheirus. Most sea lice species (66%) occurred in a single fish species only, with low infection levels. The most frequently encountered species were Caligus asperimanus Pearse, 1951, Caligus mutabilis Wilson, 1905 and Caligus rufimaculatus Wilson, 1905. Taxonomic remarks are presented for some of the species recorded during this survey. All but two sea lice records are new to Ecuador, considerably expanding the geographical range of some species.

Host specificity and the structure of helminth parasite communities of fishes in a Neotropical river in Mexico

PubMed Central

Salgado-Maldonado, Guillermo; Novelo-Turcotte, María Teresa; Caspeta-Mandujano, Juan Manuel; Vazquez-Hurtado, Gabriela; Quiroz-Martínez, Benjamin; Mercado-Silva, Norman; Favila, Mario

2016-01-01

In a tropical locality of Río La Antigua, Veracruz, Mexico, 11 fish species, represented by 244 individual fish from six freshwater fish families living sympatrically and synchronically, were examined for helminth parasites. A total of 36 taxa of helminths were recorded, 24 autogenic and 12 allogenic forms, including 6 monogeneans, 14 trematodes, 1 cestode, and 15 nematodes. Most helminth taxa were recovered for 10/11 of the component communities we analyzed. The results contribute empirical evidence that host specificity is an important force in the development of helminth communities of freshwater fishes. Each fish family has their own set of parasites, host species belonging to the same taxon share parasite species. High component community similarity among related host species was recorded, demonstrated by high prevalence and abundance, as well as dominance, of autogenic specialist species in each component community. Most autogenic helminth species are numerically and reproductively successful in relatively few host species. Autogenic helminths common in one host species are not common in others. Our findings give empirical support to the idea that low levels of sharing of parasites favor animal coexistence and high species richness, because large phylogenetic differences allow potentially competing animals to consume the same resources without being sensitive of another’s parasites. PMID:28004635

Characterization of Diet using Stomach Contents and Multivariate Statistics of four Beaufort Sea Eelpout Species

NASA Astrophysics Data System (ADS)

Apsens, S. J.; Norcross, B.

2016-02-01

Eelpouts of the genus Lycodes are a group of demersal fish commonly found in the U.S. Beaufort Sea. They are relatively numerous, having composed a significant proportion of fish catches during trawl surveys, and they are consumed by marine mammals and birds. Eelpouts themselves may also potentially feed on, or compete for resources with, other fish species. Currently, however, their exact role in the Arctic food web is still poorly understood. Percent number (%N) and percent weight (%W) were used to describe diet, and multivariate techniques were used to look for patterns across environmental (depth and longitude) and biological (length) gradients. Fish were collected in August and September of 2012 and 2014 as part of the U.S.-Canada Transboundary cruises. Stomachs from four eelpout species were examined: Adolf's Eelpout Lycodes adolfi, Canadian Eelpout L. polaris, Archers Eelpout L. sagittarius, and Longear Eelpout L. seminudus. Polychaetes, benthic amphipods, brittle stars, and harpacticoid copepods composed a large part of the observed diet for all four Lycodes species, but proportions differed by species. Intraspecific similarity was low, suggesting these fish have diverse diets even among individuals of the same species. Fish total length was found to be correlated with diet composition for all fish species examined except L. seminudus. Longitude and depth were found to be correlated with diet for L. sagittarius. Identifying prey and factors influencing diet are initial steps towards characterizing the ecological role of this fish genus in the U.S. Arctic food web. Ecological information on abundant fish species is needed for the development of ecosystem-based management practices. Establishing a benchmark for this group is important for understanding their current and future role in the rapidly changing Arctic food web.

Flat and complex temperate reefs provide similar support for fish: Evidence for a unimodal species-habitat relationship.

PubMed

Paxton, Avery B; Pickering, Emily A; Adler, Alyssa M; Taylor, J Christopher; Peterson, Charles H

2017-01-01

Structural complexity, a form of habitat heterogeneity, influences the structure and function of ecological communities, generally supporting increased species density, richness, and diversity. Recent research, however, suggests the most complex habitats may not harbor the highest density of individuals and number of species, especially in areas with elevated human influence. Understanding nuances in relationships between habitat heterogeneity and ecological communities is warranted to guide habitat-focused conservation and management efforts. We conducted fish and structural habitat surveys of thirty warm-temperate reefs on the southeastern US continental shelf to quantify how structural complexity influences fish communities. We found that intermediate complexity maximizes fish abundance on natural and artificial reefs, as well as species richness on natural reefs, challenging the current paradigm that abundance and other fish community metrics increase with increasing complexity. Naturally occurring rocky reefs of flat and complex morphologies supported equivalent abundance, biomass, species richness, and community composition of fishes. For flat and complex morphologies of rocky reefs to receive equal consideration as essential fish habitat (EFH), special attention should be given to detecting pavement type rocky reefs because their ephemeral nature makes them difficult to detect with typical seafloor mapping methods. Artificial reefs of intermediate complexity also maximized fish abundance, but human-made structures composed of low-lying concrete and metal ships differed in community types, with less complex, concrete structures supporting lower numbers of fishes classified largely as demersal species and metal ships protruding into the water column harboring higher numbers of fishes, including more pelagic species. Results of this study are essential to the process of evaluating habitat function provided by different types and shapes of reefs on the seafloor so that all EFH across a wide range of habitat complexity may be accurately identified and properly managed.

Parasites of ornamental fish commercialized in Macapá, Amapá State (Brazil).

PubMed

Hoshino, Érico de Melo; Hoshino, Maria Danielle Figueiredo Guimarães; Tavares-Dias, Marcos

2018-02-19

This study investigated the parasites fauna of four freshwater ornamental fish species in aquarium shops of Macapá, Amapá State, in addition to survey the commercialized fish species and sanitary conditions of aquarium shops. Different native and non-native ornamental fish species were found in aquarium shops, mainly Poecilidae. We examined 30 specimens of Xiphophorus maculatus, 30 Danio rerio, 30 Paracheirodon axelrodi, and 30 Corydoras ephippifer for parasites. Of the 120 fish examined, 22.5% were parasitized by one or more species and a total of 438 parasites were collected and identified. Parasites such as: Ichthyophthirius multifiliis, Monogenea, undermined Digenea metacercariae, Acanthostomum sp. metacercariae, Camallanus spp., Bothriocephalus acheilognathi and Echinorhynchus sp. infected the hosts examined. Endoparasites in the larval stage showed the greatest diversity and Camallanus spp. was found in all hosts species examined. Paracheirodon axelrodi (43.3%) was the most parasitized host, while C. ephippifer (6.7%) was the least parasitized. Despite the low ectoparasites level, six species of endoparasites was observed, demonstrating that prophylactic and quarantine procedures were not fully adequate. Therefore, failures in prophylactic procedures on any link in the production industry of ornamental fish may cause parasite transmission to ornamental fish captured in different environments and localities.

Parasites of ornamental fish commercialized in Macapá, Amapá State (Brazil).

PubMed

Hoshino, Érico de Melo; Hoshino, Maria Danielle Figueiredo Guimarães; Tavares-Dias, Marcos

2018-01-01

This study investigated the parasites fauna of four freshwater ornamental fish species in aquarium shops of Macapá, Amapá State, in addition to survey the commercialized fish species and sanitary conditions of aquarium shops. Different native and non-native ornamental fish species were found in aquarium shops, mainly Poecilidae. We examined 30 specimens of Xiphophorus maculatus, 30 Danio rerio, 30 Paracheirodon axelrodi, and 30 Corydoras ephippifer for parasites. Of the 120 fish examined, 22.5% were parasitized by one or more species and a total of 438 parasites were collected and identified. Parasites such as: Ichthyophthirius multifiliis, Monogenea, undermined Digenea metacercariae, Acanthostomum sp. metacercariae, Camallanus spp., Bothriocephalus acheilognathi and Echinorhynchus sp. infected the hosts examined. Endoparasites in the larval stage showed the greatest diversity and Camallanus spp. was found in all hosts species examined. Paracheirodon axelrodi (43.3%) was the most parasitized host, while C. ephippifer (6.7%) was the least parasitized. Despite the low ectoparasites level, six species of endoparasites was observed, demonstrating that prophylactic and quarantine procedures were not fully adequate. Therefore, failures in prophylactic procedures on any link in the production industry of ornamental fish may cause parasite transmission to ornamental fish captured in different environments and localities.

Richness patterns in the parasite communities of exotic poeciliid fishes.

PubMed

Dove, A D

2000-06-01

Three species of poeciliids (Gambusia holbrooki, Xiphophorus helleri and X. maculatus) and 15 species of ecologically similar native freshwater fishes (mainly eleotrids, ambassids, melanotaeniids and retropinnids) were examined for parasite richness to investigate parasite flux, qualitative differences, quantitative differences and the structuring factors in parasite communities in the 2 fish types in Queensland, Australia. Theory suggests that poeciliids would harbour depauperate parasite communities. Results supported this hypothesis; poeciliids harboured more species-poor parasite infracommunities and regional faunas than natives (P < 0.0001), despite greater sampling effort for the former. Cluster analysis of presence/absence data for poeciliids and the 6 most-sampled native fishes revealed that parasite communities of the 2 fish groups are qualitatively distinct; the proportion of parasite species with complex life-cycles was lower in poeciliids than in native species, and Myxosporea, Microspora, Coccidia and parasitic Crustacea were all absent from poeciliids. Limited exchange of parasite species has occurred between natives and poeciliids. Logistic ordinal regression analysis revealed that fish origin (exotic or native), environmental disturbance and host sex were all significant determinants of parasite community richness (P < 0.05). Theoretical modelling suggests that poeciliids are at a competitive advantage over native fishes because of their lack of parasites.

Novel approach for the simultaneous detection of DNA from different fish species based on a nuclear target: quantification potential.

PubMed

Prado, Marta; Boix, Ana; von Holst, Christoph

2012-07-01

The development of DNA-based methods for the identification and quantification of fish in food and feed samples is frequently focused on a specific fish species and/or on the detection of mitochondrial DNA of fish origin. However, a quantitative method for the most common fish species used by the food and feed industry is needed for official control purposes, and such a method should rely on the use of a single-copy nuclear DNA target owing to its more stable copy number in different tissues. In this article, we report on the development of a real-time PCR method based on the use of a nuclear gene as a target for the simultaneous detection of fish DNA from different species and on the evaluation of its quantification potential. The method was tested in 22 different fish species, including those most commonly used by the food and feed industry, and in negative control samples, which included 15 animal species and nine feed ingredients. The results show that the method reported here complies with the requirements concerning specificity and with the criteria required for real-time PCR methods with high sensitivity.

Recent warming leads to a rapid borealization of fish communities in the Arctic

NASA Astrophysics Data System (ADS)

Fossheim, Maria; Primicerio, Raul; Johannesen, Edda; Ingvaldsen, Randi B.; Aschan, Michaela M.; Dolgov, Andrey V.

2015-07-01

Arctic marine ecosystems are warming twice as fast as the global average. As a consequence of warming, many incoming species experience increasing abundances and expanding distribution ranges in the Arctic. The Arctic is expected to have the largest species turnover with regard to invading and locally extinct species, with a modelled invasion intensity of five times the global average. Studies in this region might therefore give valuable insights into community-wide shifts of species driven by climate warming. We found that the recent warming in the Barents Sea has led to a change in spatial distribution of fish communities, with boreal communities expanding northwards at a pace reflecting the local climate velocities. Increased abundance and distribution areas of large, migratory fish predators explain the observed community-wide distributional shifts. These shifts change the ecological interactions experienced by Arctic fish species. The Arctic shelf fish community retracted northwards to deeper areas bordering the deep polar basin. Depth might limit further retraction of some of the fish species in the Arctic shelf community. We conclude that climate warming is inducing structural change over large spatial scales at high latitudes, leading to a borealization of fish communities in the Arctic.

Evaluation of Application Space Expansion for the Sensor Fish

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeRolph, Christopher R.; Bevelhimer, Mark S.

The Pacific Northwest National Laboratory has developed an instrument known as the sensor fish that can be released into downstream passage routes at hydropower facilities to collect data on the physical conditions that a fish might be exposed to during passage through a turbine. The US Department of Energy Wind and Water Power Program sees value in expanding the sensor fish application space beyond large Kaplan turbines in the northwest United States to evaluate conditions to which a greater variety of fish species are exposed. Development of fish-friendly turbines requires an understanding of both physical passage conditions and biological responsesmore » to those conditions. Expanding the use of sensor fish into other application spaces will add to the knowledge base of physical passage conditions and could also enhance the use of sensor fish as a site-specific tool in mitigating potential impacts to fish populations from hydropower. The Oak Ridge National Laboratory (ORNL) National Hydropower Assessment Program (NHAAP) database contains hydropower facility characteristics that, along with national fish distribution data, were used to evaluate potential interactions between fish species and project characteristics related to downstream passage issues. ORNL developed rankings for the turbine types in the NHAAP database in terms of their potential to impact fish through injury or mortality during downstream turbine passage. National-scale fish distributions for 31 key migratory species were spatially intersected with hydropower plant locations to identify facilities where turbines with a high threat to fish injury or mortality overlap with the potential range of a sensitive fish species. A dataset was produced that identifies hydropower facilities where deployment of the sensor fish technology might be beneficial in addressing issues related to downstream fish passage. The dataset can be queried to target specific geographic regions, fish species, license expiration dates, generation capacity levels, ownership characteristics, turbine characteristics, or any combination of these metrics.« less

Autocrine Positive Feedback Regulation of Prolactin Release From Tilapia Prolactin Cells and Its Modulation by Extracellular Osmolality.

PubMed

Yamaguchi, Yoko; Moriyama, Shunsuke; Lerner, Darren T; Grau, E Gordon; Seale, Andre P

2016-09-01

Prolactin (PRL) is a vertebrate hormone with diverse actions in osmoregulation, metabolism, reproduction, and in growth and development. Osmoregulation is fundamental to maintaining the functional structure of the macromolecules that conduct the business of life. In teleost fish, PRL plays a critical role in osmoregulation in fresh water. Appropriately, PRL cells of the tilapia are directly osmosensitive, with PRL secretion increasing as extracellular osmolality falls. Using a model system that employs dispersed PRL cells from the euryhaline teleost fish, Oreochromis mossambicus, we investigated the autocrine regulation of PRL cell function. Unknown was whether these PRL cells might also be sensitive to autocrine feedback and whether possible autocrine regulation might interact with the well-established regulation by physiologically relevant changes in extracellular osmolality. In the cell-perfusion system, ovine PRL and two isoforms of tilapia PRL (tPRL), tPRL177 and tPRL188, stimulated the release of tPRLs from the dispersed PRL cells. These effects were significant within 5-10 minutes and lasted the entire course of exposure, ceasing within 5-10 minutes of removal of tested PRLs from the perifusion medium. The magnitude of response varied between tPRL177 and tPRL188 and was modulated by extracellular osmolality. On the other hand, the gene expression of tPRLs was mainly unchanged or suppressed by static incubations of PRL cells with added PRLs. By demonstrating the regulatory complexity driven by positive autocrine feedback and its interaction with osmotic stimuli, these findings expand upon the knowledge that pituitary PRL cells are regulated complexly through multiple factors and interactions.

Effect of Phase Shift from Corals to Zoantharia on Reef Fish Assemblages

PubMed Central

Cruz, Igor C. S.; Loiola, Miguel; Albuquerque, Tiago; Reis, Rodrigo; de Anchieta C. C. Nunes, José; Reimer, James D.; Mizuyama, Masaru; Kikuchi, Ruy K. P.; Creed, Joel C.

2015-01-01

Consequences of reef phase shifts on fish communities remain poorly understood. Studies on the causes, effects and consequences of phase shifts on reef fish communities have only been considered for coral-to-macroalgae shifts. Therefore, there is a large information gap regarding the consequences of novel phase shifts and how these kinds of phase shifts impact on fish assemblages. This study aimed to compare the fish assemblages on reefs under normal conditions (relatively high cover of corals) to those which have shifted to a dominance of the zoantharian Palythoa cf. variabilis on coral reefs in Todos os Santos Bay (TSB), Brazilian eastern coast. We examined eight reefs, where we estimated cover of corals and P. cf. variabilis and coral reef fish richness, abundance and body size. Fish richness differed significantly between normal reefs (48 species) and phase-shift reefs (38 species), a 20% reduction in species. However there was no difference in fish abundance between normal and phase shift reefs. One fish species, Chaetodon striatus, was significantly less abundant on normal reefs. The differences in fish assemblages between different reef phases was due to differences in trophic groups of fish; on normal reefs carnivorous fishes were more abundant, while on phase shift reefs mobile invertivores dominated. PMID:25629532

Host population density as the major determinant of endoparasite species richness in floodplain fishes of the upper Paraná River, Brazil.

PubMed

Takemoto, R M; Pavanelli, G C; Lizama, M A P; Luque, J L; Poulin, R

2005-03-01

A comparative analysis of parasite species richness was performed across 53 species of fish from the floodplain of the upper Paraná River, Brazil. Values of catch per unit effort, CPUE (number of individuals of a given fish species captured per 1000 m(2) of net during 24 h) were used as a rough measure of population density for each fish species in order to test its influence on endoparasite species richness. The effects of several other host traits (body size, social behaviour, reproductive behaviour, spawning type, trophic category, feeding habits, relative position in the food web, preference for certain habitats and whether the fish species are native or exotic) on metazoan endoparasite species richness were also evaluated. The CPUE was the sole significant predictor of parasite species richness, whether controlling for the confounding influences of host phylogeny and sampling effort or not. The results suggest that in the floodplain of the upper Paraná River (with homogeneous physical characteristics and occurrence of many flood pulses), population density of different host species might be the major determinant of their parasite species richness.

Environmental factors structuring fish composition and assemblages in a small macrotidal estuary (eastern English Channel)

NASA Astrophysics Data System (ADS)

Selleslagh, Jonathan; Amara, Rachid

2008-09-01

The fish assemblage structure was analyzed along an estuarine gradient of a small macrotidal estuary (the Canche, France). Fishes were collected every two months between May 2006 and July 2007 from 12 sampling stations using a 1.5-m beam trawl with a 5 mm mesh size in the cod end. To complement this information, sampling was also performed using 15-m fyke nets (8 mm mesh size in the cod end). For each sample, abiotic (temperature, salinity, pH, oxygen, turbidity, river flow, wind speed and depth) and biotic (macro crustacean species abundances) were recorded. Throughout the study, 28 fish species belonging to 20 families were collected. Fish catches were dominated by juveniles, especially Young-Of-the-Year (YOY) for the majority of the species. According to the Index of Relative Importance (IRI), common goby Pomatoschistus microps, flounder Platichtys flesus, sprat Sprattus sprattus, sea-bass Dicentrarchus labrax and plaice Pleuronectes platessa were the most abundant species, together accounting for 99.2% of the total IRI. Estuarine residents (ER = 66.2%) and marine juvenile migrants species (MJ = 31.4%) were the most important ecological guilds. The structure of the fish assemblage and its relationship to environmental variables was examined using multivariate techniques. Cluster and non-metric multidimensional scaling (nMDS) analysis defined six distinct groups in the Canche estuary, which are discriminated by specific species (SIMPER). Spatio-temporal variations in fish assemblage structure reflect the density peaks of the most abundant species. Spearman rank correlations and canonical correspondence analysis (CCA) showed that among the ten environmental variables examined, temperature, salinity and Crangon crangon (a potential predator for YOY fish or prey for older ones) are the three most important factors influencing fish species richness and abundances. Our observations reinforce the idea that certain fish species may have different life history styles in different geographic areas. The present study highlights the necessity of a better knowledge of the connectivity between estuaries and adjacent marine areas. The Canche constitutes an important ecosystem for fishes and as it is subject to little anthropogenic disturbance; its ichthyofauna can be viewed as a reference or normal assemblage for small temperate macrotidal estuaries.

Effect of frying, grilling, and steaming on amino acid composition of marine fishes.

PubMed

Erkan, Nuray; Özden, Özkan; Selçuk, Arif

2010-12-01

Amino acid and proximate compositions were determined in six raw and cooked marine fish species that are commonly consumed in Turkey. The changes in amino acid and proximate content were found to be significant for all cooking methods in all fish species. Cooking did, in general, significantly increase the contents of essential, semiessential, and other amino acids compared with raw fish species. Grilled Atlantic bonito, anchovy, and bluefish and fried mullet and hake appeared to be more valuable fish dishes for obtaining the officially recommended appropriate daily intake of essential amino acids for humans. Moisture, fat, ash, and carbohydrate contents of raw fish ranged between 48.01% and 83.05%, 0.87% and 30.48%, 1.10% and 1.61%, and 0.09% and 8.70%, respectively. All fresh fish investigated were high in protein: 11.20-17.14 g/100 g. Wide variations in protein content (18.11-25.65 g/100 g) between species and methods of cooking were observed. Fried fish had intermediate fat values, whereas grilled and steamed fishes had a comparatively low value.

Predictive models for fish assemblages in eastern USA streams: implications for assessing biodiversity

USGS Publications Warehouse

Meador, Michael R.; Carlisle, Daren M.

2009-01-01

Management and conservation of aquatic systems require the ability to assess biological conditions and identify changes in biodiversity. Predictive models for fish assemblages were constructed to assess biological condition and changes in biodiversity for streams sampled in the eastern United States as part of the U.S. Geological Survey's National Water Quality Assessment Program. Separate predictive models were developed for northern and southern regions. Reference sites were designated using land cover and local professional judgment. Taxonomic completeness was quantified based on the ratio of the number of observed native fish species expected to occur to the number of expected native fish species. Models for both regions accurately predicted fish species composition at reference sites with relatively high precision and low bias. In general, species that occurred less frequently than expected (decreasers) tended to prefer riffle areas and larger substrates, such as gravel and cobble, whereas increaser species (occurring more frequently than expected) tended to prefer pools, backwater areas, and vegetated and sand substrates. In the north, the percentage of species identified as increasers and the percentage identified as decreasers were equal, whereas in the south nearly two-thirds of the species examined were identified as decreasers. Predictive models of fish species can provide a standardized indicator for consistent assessments of biological condition at varying spatial scales and critical information for an improved understanding of fish species that are potentially at risk of loss with changing water quality conditions.

Connecting ground water influxes with fish species diversity in an urbanized watershed

USGS Publications Warehouse

Steffy, L.Y.; McGinty, A.L.; Welty, C.; Kilham, S.S.

2004-01-01

Valley Creek watershed is a small stream system that feeds the Schuylkill River near Philadelphia, Pennsylvania. The watershed is highly urbanized, including over 17 percent impervious surface cover (ISC) by area. Imperviousness in a watershed has been linked to fish community structure and integrity. Generally, above 10 to 12 percent ISC there is marked decline in fish assemblages with fish being absent above 25 percent ISC. This study quantifies the importance of ground water in maintaining fish species diversity in subbasins with over 30 percent ISC. Valley Creek contains an atypical fish assemblage in that the majority of the fish are warm-water species, and the stream supports naturally reproducing brown trout, which were introduced and stocked from the early 1900s to 1985. Fish communities were quantified at 13 stations throughout the watershed, and Simpson's species diversity index was calculated. One hundred and nine springs were located, and their flow rates measured. A cross covariance analysis between Simpson's species diversity index and spring flow rates upstream of fish stations was performed to quantify the spatial correlation between these two variables. The correlation was found to be highest at lag distances up to about 400 m and drop off significantly beyond lag distances of about 800 m.

Parasites of forage fishes in the vicinity of Steller sea lion (Eumetopias jubatus) habitat in Alaska.

PubMed

Moles, A; Heintz, R A

2007-07-01

Fish serve as intermediate hosts for a number of larval parasites that have the potential of maturing in marine mammals such as Steller sea lions (Eumetopias jubatus). We examined the prevalence of parasites from 229 fish collected between March and July 2002 near two islands used by Steller sea lions in Southeast Alaska and island habitats in the Aleutian Islands. Sea lion populations have remained steady in Southeast Alaska but have been declining over the last 30 yr in the Aleutian Islands. Even though the fish samples near the Southeast Alaska haul-outs were composed of numerous small species of fish and the Aleutian Islands catch was dominated by juveniles of commercially harvested species, the parasite fauna was similar at all locations. Eleven of the 20 parasite taxa identified were in their larval stage in the fish hosts, several of which have been described from mammalian final hosts. Four species of parasite were more prevalent in Southeast Alaska fish samples, and seven parasite species, including several larval forms capable of infecting marine mammals, were more prevalent in fish from the Aleutian Islands. Nevertheless, parasites available to Steller sea lions from common fish prey are not likely to be a major factor in the decline of this marine mammal species.

Fish biodiversity and conservation in South America.

PubMed

Reis, R E; Albert, J S; Di Dario, F; Mincarone, M M; Petry, P; Rocha, L A

2016-07-01

The freshwater and marine fish faunas of South America are the most diverse on Earth, with current species richness estimates standing above 9100 species. In addition, over the last decade at least 100 species were described every year. There are currently about 5160 freshwater fish species, and the estimate for the freshwater fish fauna alone points to a final diversity between 8000 and 9000 species. South America also has c. 4000 species of marine fishes. The mega-diverse fish faunas of South America evolved over a period of >100 million years, with most lineages tracing origins to Gondwana and the adjacent Tethys Sea. This high diversity was in part maintained by escaping the mass extinctions and biotic turnovers associated with Cenozoic climate cooling, the formation of boreal and temperate zones at high latitudes and aridification in many places at equatorial latitudes. The fresh waters of the continent are divided into 13 basin complexes, large basins consolidated as a single unit plus historically connected adjacent coastal drainages, and smaller coastal basins grouped together on the basis of biogeographic criteria. Species diversity, endemism, noteworthy groups and state of knowledge of each basin complex are described. Marine habitats around South America, both coastal and oceanic, are also described in terms of fish diversity, endemism and state of knowledge. Because of extensive land use changes, hydroelectric damming, water divergence for irrigation, urbanization, sedimentation and overfishing 4-10% of all fish species in South America face some degree of extinction risk, mainly due to habitat loss and degradation. These figures suggest that the conservation status of South American freshwater fish faunas is better than in most other regions of the world, but the marine fishes are as threatened as elsewhere. Conserving the remarkable aquatic habitats and fishes of South America is a growing challenge in face of the rapid anthropogenic changes of the 21st century, and deserves attention from conservationists and policy makers. © 2016 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

Current status of non-native fish species in the St. Louis River estuary

EPA Science Inventory

The fish community of the St. Louis River estuary is well characterized, thanks to fishery assessment and invasive species early detection monitoring by federal, state, and tribal agencies. This sampling includes long-standing adult/juvenile fish surveys, larval fish surveys beg...

77 FR 42278 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-18

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations governing listed fish and wildlife permits (50 CFR parts 222-226). NMFS issues permits based on.... This project will examine predation by introduced fishes (striped bass, largemouth bass, smallmouth...

Analysis of habitat characteristics of small pelagic fish based on generalized additive models in Kepulauan Seribu Waters

NASA Astrophysics Data System (ADS)

Rivai, A. A.; Siregar, V. P.; Agus, S. B.; Yasuma, H.

2018-03-01

One of the required information for sustainable fisheries management is about the habitat characteristics of a fish species. This information can be used to map the distribution of fish and map the potential fishing ground. This study aimed to analyze the habitat characteristics of small pelagic fishes (anchovy, squid, sardine and scads) which were mainly caught by lift net in Kepulauan Seribu waters. Research on habitat characteristics had been widely done, but the use of total suspended solid (TSS) parameters in this analysis is still lacking. TSS parameter which was extracted from Landsat 8 along with five other oceanographic parameters, CPUE data and location of fishing ground data from lift net fisheries in Kepulauan Seribu were included in this analysis. This analysis used Generalized Additive Models (GAMs) to evaluate the relationship between CPUE and oceanographic parameters. The results of the analysis showed that each fish species had different habitat characteristics. TSS and sea surface height had a great influence on the value of CPUE from each species. All the oceanographic parameters affected the CPUE of each species. This study demonstrated the effective use of GAMs to identify the essential habitat of a fish species.

Estimation and modeling of electrofishing capture efficiency for fishes in wadeable warmwater streams

USGS Publications Warehouse

Price, A.; Peterson, James T.

2010-01-01

Stream fish managers often use fish sample data to inform management decisions affecting fish populations. Fish sample data, however, can be biased by the same factors affecting fish populations. To minimize the effect of sample biases on decision making, biologists need information on the effectiveness of fish sampling methods. We evaluated single-pass backpack electrofishing and seining combined with electrofishing by following a dual-gear, mark–recapture approach in 61 blocknetted sample units within first- to third-order streams. We also estimated fish movement out of unblocked units during sampling. Capture efficiency and fish abundances were modeled for 50 fish species by use of conditional multinomial capture–recapture models. The best-approximating models indicated that capture efficiencies were generally low and differed among species groups based on family or genus. Efficiencies of single-pass electrofishing and seining combined with electrofishing were greatest for Catostomidae and lowest for Ictaluridae. Fish body length and stream habitat characteristics (mean cross-sectional area, wood density, mean current velocity, and turbidity) also were related to capture efficiency of both methods, but the effects differed among species groups. We estimated that, on average, 23% of fish left the unblocked sample units, but net movement varied among species. Our results suggest that (1) common warmwater stream fish sampling methods have low capture efficiency and (2) failure to adjust for incomplete capture may bias estimates of fish abundance. We suggest that managers minimize bias from incomplete capture by adjusting data for site- and species-specific capture efficiency and by choosing sampling gear that provide estimates with minimal bias and variance. Furthermore, if block nets are not used, we recommend that managers adjust the data based on unconditional capture efficiency.

Littoral fish assemblages of the alien-dominated Sacramento-San Joaquin Delta, California, 1980-1983 and 2001-2003

USGS Publications Warehouse

Brown, L.R.; Michniuk, D.

2007-01-01

We analyzed monthly boat electrofishing data to characterize the littoral fish assemblages of five regions of the Sacramento-San Joaquin Delta (northern, southern, eastern, western, and central), California, during two sampling periods, 1980-1983 (1980s) and 2001-2003 (2000s), to provide information pertinent to the restoration of fish populations in this highly altered estuary. During the 1980s, almost 11,000 fish were captured, including 13 native species and 24 alien species. During the 2000s, just over 39,000 fish were captured, including 15 native species and 24 alien species. Catch per unit effort (CPUE) of total fish, alien fish, and centrarchid fish were greater in the 2000s compared with the 1980s, largely because of increased centrarchid fish CPUE. These differences in CPUE were associated with the spread of submerged aquatic vegetation (SAV), particularly an alien aquatic macrophyte Egeria densa. Native fish CPUE declined from the 1980s to the 2000s, but there was no single factor that could explain the decline. Native fish were most abundant in the northern region during both sampling periods. Nonmetric multidimensional scaling indicated similar patterns of fish assemblage composition during the two sampling periods, with the northern and western regions characterized by the presence of native species. The separation of the northern and western regions from the other regions was most distinct in the 2000s. Our results suggest that native fish restoration efforts will be most successful in the northern portion of the Delta. Management decisions on the Delta should include consideration of possible effects on SAV in littoral habitats and the associated fish assemblages and ecological processes. ?? 2007 Estuarine Research Federation.

Development of DNA-based Identification methods to track the ...

EPA Pesticide Factsheets

The ability to track the identity and abundance of larval fish, which are ubiquitous during spawning season, may lead to a greater understanding of fish species distributions in Great Lakes nearshore areas including early-detection of invasive fish species before they become established. However, larval fish are notoriously hard to identify using traditional morphological techniques. While DNA-based identification methods could increase the ability of aquatic resource managers to determine larval fish composition, use of these methods in aquatic surveys is still uncommon and presents many challenges. In response to this need, we have been working with the U. S. Fish and Wildlife Service to develop field and laboratory methods to facilitate the identification of larval fish using DNA-meta-barcoding. In 2012, we initiated a pilot-project to develop a workflow for conducting DNA-based identification, and compared the species composition at sites within the St. Louis River Estuary of Lake Superior using traditional identification versus DNA meta-barcoding. In 2013, we extended this research to conduct DNA-identification of fish larvae collected from multiple nearshore areas of the Great Lakes by the USFWS. The species composition of larval fish generally mirrored that of fish species known from the same areas, but was influenced by the timing and intensity of sampling. Results indicate that DNA-based identification needs only very low levels of biomass to detect pre

Accumulation features of arsenic species in various fishes collected from coastal cities in Korea

NASA Astrophysics Data System (ADS)

Choi, Sung-Deuk; Son, Hee-Sik; Choi, Minkyu; Park, Min-Kyu

2015-12-01

In this study, 36 fish species were collected from three coastal cities in Korea to investigate levels and patterns of six arsenicals (arsenite: As (III), arsenate: As (V), arsenocholine: AsC, arsenobetaine: AsB, monomethylarsonic acid: MMA, and dimethylarsinic acid: DMA). The levels of ∑6 As in the different fish species varied substantially, ranging from 0.02 μg As/g ww (Islaeli carp) to 9.65 μg As/g ww (Skate ray) with a median of 0.40 μg As/g ww. All the arsenicals in marine fishes showed higher levels than those in freshwater fishes due to fish feed living in saline water. Overall, marine carnivorous fishes seem to be more contaminated with arsenic. For all the fish samples, AsB (mean fraction: 90.6%) was dominant among the six arsenicals, indicating biomethylation of inorganic arsenic and accumulation of AsB. Fish species with high water contents showed elevated levels of As (III), but there was no further significant correlations between arsenicals and water/lipid contents. Concentrations of As (V) were significantly lower than those of As (III), which implies that As (V) is reduced during biomethylation of inorganic arsenic. Consequently, we hypothesize that the toxicity of arsenic (mainly derived from As (III)) can be increased by the reduction of As (V), especially for the fish species with higher water contents.

Elevational Gradients in Fish Diversity in the Himalaya: Water Discharge Is the Key Driver of Distribution Patterns

PubMed Central

Bhatt, Jay P.; Manish, Kumar; Pandit, Maharaj K.

2012-01-01

Background Studying diversity and distribution patterns of species along elevational gradients and understanding drivers behind these patterns is central to macroecology and conservation biology. A number of studies on biogeographic gradients are available for terrestrial ecosystems, but freshwater ecosystems remain largely neglected. In particular, we know very little about the species richness gradients and their drivers in the Himalaya, a global biodiversity hotspot. Methodology/Principal Findings We collated taxonomic and distribution data of fish species from 16 freshwater Himalayan rivers and carried out empirical studies on environmental drivers and fish diversity and distribution in the Teesta river (Eastern Himalaya). We examined patterns of fish species richness along the Himalayan elevational gradients (50–3800 m) and sought to understand the drivers behind the emerging patterns. We used generalized linear models (GLM) and generalized additive models (GAM) to examine the richness patterns; GLM was used to investigate relationship between fish species richness and various environmental variables. Regression modelling involved stepwise procedures, including elimination of collinear variables, best model selection, based on the least Akaike’s information criterion (AIC) and the highest percentage of deviance explained (D2). This maiden study on the Himalayan fishes revealed that total and non-endemic fish species richness monotonously decrease with increasing elevation, while endemics peaked around mid elevations (700–1500 m). The best explanatory model (synthetic model) indicated that water discharge is the best predictor of fish species richness patterns in the Himalayan rivers. Conclusions/Significance This study, carried out along one of the longest bioclimatic elevation gradients of the world, lends support to Rapoport’s elevational rule as opposed to mid domain effect hypothesis. We propose a species-discharge model and contradict species-area model in predicting fish species richness. We suggest that drivers of richness gradients in terrestrial and aquatic ecosystems are likely to be different. These studies are crucial in context of the impacts of unprecedented on-going river regulation on fish diversity and distribution in the Himalaya. PMID:23029444

Application of denaturing high-performance liquid chromatography (DHPLC) for the identification of fish: a new way to determine the composition of processed food containing multiple species.

PubMed

Le Fresne, Sophie; Popova, Milena; Le Vacon, Françoise; Carton, Thomas

2011-12-14

The identification of fish species in transformed food products is difficult because the existing methods are not adapted to heat-processed products containing more than one species. Using a common to all vertebrates region of the cytochrome b gene, we have developed a denaturing high-performance liquid chromatography (DHPLC) fingerprinting method, which allowed us to identify most of the species in commercial crab sticks. Whole fish and fillets were used for the creation of a library of referent DHPLC profiles. Crab sticks generated complex DHPLC profiles in which the number of contained fish species can be estimated by the number of major fluorescence peaks. The identity of some of the species was predicted by comparison of the peaks with the referent profiles, and others were identified after collection of the peak fractions, reamplification, and sequencing. DHPLC appears to be a quick and efficient method to analyze the species composition of complex heat-processed fish products.

Species-specific responses to landscape fragmentation: implications for management strategies

PubMed Central

Blanchet, Simon; Rey, Olivier; Etienne, Roselyne; Lek, Sovan; Loot, Géraldine

2010-01-01

Habitat fragmentation affects the integrity of many species, but little is known about species-specific sensitivity to fragmentation. Here, we compared the genetic structure of four freshwater fish species differing in their body size (Leuciscus cephalus; Leuciscus leuciscus; Gobio gobio and Phoxinus phoxinus) between a fragmented and a continuous landscape. We tested if, overall, fragmentation affected the genetic structure of these fish species, and if these species differed in their sensitivity to fragmentation. Fragmentation negatively affected the genetic structure of these species. Indeed, irrespective of the species identity, allelic richness and heterozygosity were lower, and population divergence was higher in the fragmented than in the continuous landscape. This response to fragmentation was highly species-specific, with the smallest fish species (P. phoxinus) being slightly affected by fragmentation. On the contrary, fish species of intermediate body size (L. leuciscus and G. gobio) were highly affected, whereas the largest fish species (L. cephalus) was intermediately affected by fragmentation. We discuss the relative role of dispersal ability and effective population size on the responses to fragmentation we report here. The weirs studied here are of considerable historical importance. We therefore conclude that restoration programmes will need to consider both this societal context and the biological characteristics of the species sharing this ecosystem. PMID:25567925

Selenium:Mercury Molar Ratios in Freshwater Fish from Tennessee: Individual, Species, and Geographical Variations have Implications for Management

PubMed Central

Burger, Joanna; Gochfeld, Michael; Jeitner, C.; Donio, M.; Pittfield, T.

2014-01-01

Vertebrates, including humans, can experience adverse effects from mercury consumed in fish. Humans often prefer large predatory fish that bioaccumulate high mercury levels. Recent attention has focused on the role of selenium countering mercury toxicity, but there is little research on the selenium:mercury molar ratios in freshwater fish. We examine selenium:mercury molar ratios in freshwater fish from Tennessee at Poplar Creek which receives ongoing inputs of mercury from the Department of Energy’s Oak Ridge Y-12 facility. Our objective was to determine variation of the ratios within species that might affect the protectiveness of selenium against mercury toxicity. Within species, the ratio was correlated significantly and positively with fish length only for two species. There was great individual variation in the selenium:mercury molar ratio within each species, except striped bass. The lack of a clear relationship between the selenium:mercury molar ratio and fish length, and the intraspecific variation, suggests that it would be difficult to use the molar ratio in predicting either the risk from mercury toxicity or in devising consumption advisories. PMID:22456727

Determining the mechanism by which fish diversity influences production.

PubMed

Carey, Michael P; Wahl, David H

2011-09-01

Understanding the ability of biodiversity to govern ecosystem function is essential with current pressures on natural communities from species invasions and extirpations. Changes in fish communities can be a major determinant of food web dynamics, and even small shifts in species composition or richness can translate into large effects on ecosystems. In addition, there is a large information gap in extrapolating results of small-scale biodiversity-ecosystem function experiments to natural systems with realistic environmental complexity. Thus, we tested the key mechanisms (resource complementarity and selection effect) for biodiversity to influence fish production in mesocosms and ponds. Fish diversity treatments were created by replicating species richness and species composition within each richness level. In mesocosms, increasing richness had a positive effect on fish biomass with an overyielding pattern indicating species mixtures were more productive than any individual species. Additive partitioning confirmed a positive net effect of biodiversity driven by a complementarity effect. Productivity was less affected by species diversity when species were more similar. Thus, the primary mechanism driving fish production in the mesocosms was resource complementarity. In the ponds, the mechanism driving fish production changed through time. The key mechanism was initially resource complementarity until production was influenced by the selection effect. Varying strength of intraspecific interactions resulting from differences in resource levels and heterogeneity likely caused differences in mechanisms between the mesocosm and pond experiments, as well as changes through time in the ponds. Understanding the mechanisms by which fish diversity governs ecosystem function and how environmental complexity and resource levels alter these relationships can be used to improve predictions for natural systems.

Fishes of Southwestern Grasslands: Ecology, Conservation, and Management

Treesearch

Bob Calamusso

2005-01-01

The world possesses an amazing number and variety of freshwater fishes. Fish, the most diverse taxon on Earth, exhibit more species than all vertebrate taxa combined (Hocutt and Wiley 1986, May 1988, Nelson 1994, Matthews 1998) (table 5-1). Worldwide, an estimated 28,500 fish species are in 57 orders and 482 families (Nelson 1994). The North American freshwater fish...

Species- and tissue-specific mercury bioaccumulation in five fish species from Laizhou Bay in the Bohai Sea of China

NASA Astrophysics Data System (ADS)

Liu, Jinhu; Cao, Liang; Huang, Wei; Dou, Shuozeng

2013-05-01

Mercury (Hg) concentrations in the tissues (muscle, stomach, liver, gills, skin, and gonads) of five fish species (mullet Liza ha em atocheil us, flathead fish Platycephalus indicus, sea bass Lateolabrax japonic u s, mackerel Scomberomorus niphonius and silver pomfret Pampus argenteus) collected from Laizhou Bay in the Bohai Sea of China were investigated. The results indicate that Hg bioaccumulation in the five fish was tissue-specific, with the highest levels in the muscle and liver, followed by the stomach and gonads. The lowest levels were found in the gills and skin. Fish at higher trophic levels (flathead fish and sea bass) exhibited higher Hg concentrations than consumers at lower trophic levels. Mercury bioaccumulation tended to be positively correlated with fish length in mullet, silver pomfret, mackerel, and flathead fish, but was negatively correlated with fish length in sea bass. The Hg concentrations in the muscles of all fish species in Laizhou Bay were within the permissible limits of food safety set by national and international criteria. However, the suggesting maximum consumption of sea bass is 263 g per week for human health.

Fish Karyome: A karyological information network database of Indian Fishes.

PubMed

Nagpure, Naresh Sahebrao; Pathak, Ajey Kumar; Pati, Rameshwar; Singh, Shri Prakash; Singh, Mahender; Sarkar, Uttam Kumar; Kushwaha, Basdeo; Kumar, Ravindra

2012-01-01

'Fish Karyome', a database on karyological information of Indian fishes have been developed that serves as central source for karyotype data about Indian fishes compiled from the published literature. Fish Karyome has been intended to serve as a liaison tool for the researchers and contains karyological information about 171 out of 2438 finfish species reported in India and is publically available via World Wide Web. The database provides information on chromosome number, morphology, sex chromosomes, karyotype formula and cytogenetic markers etc. Additionally, it also provides the phenotypic information that includes species name, its classification, and locality of sample collection, common name, local name, sex, geographical distribution, and IUCN Red list status. Besides, fish and karyotype images, references for 171 finfish species have been included in the database. Fish Karyome has been developed using SQL Server 2008, a relational database management system, Microsoft's ASP.NET-2008 and Macromedia's FLASH Technology under Windows 7 operating environment. The system also enables users to input new information and images into the database, search and view the information and images of interest using various search options. Fish Karyome has wide range of applications in species characterization and identification, sex determination, chromosomal mapping, karyo-evolution and systematics of fishes.

Risks and benefits of fish consumption for childbearing women.

PubMed

Del Gobbo, Liana C; Archbold, Josephine A; Vanderlinden, Loren D; Eckley, Chris S; Diamond, Miriam L; Robson, Matthew

2010-01-01

Pregnant women's fish consumption provides both benefits and risks to the developing fetus. Docosahexaenoic acid (DHA) from fish may enhance fetal neurodevelopment, while methylmercury (MeHg) can have detrimental effects. Dietitians would benefit from information on the frequency with which fish species may be consumed to increase DHA intake among Canadian women of childbearing age, and on minimizing the risks from MeHg, especially for those who consume fish frequently. Eighteen fish species were selected for DHA and mercury analysis from retail markets in the Toronto area. Consumption scenarios using analytical results for these fish species indicate that women of childbearing age can consume nine of 18 fish species every day (14 servings a week) or often (up to four servings a week) and remain below toxicological benchmarks for mercury. Moreover, women can also attain the recommended DHA level by consuming six of those nine fish: four 75-g servings of smelt, porgie, or bluefish a week, or two 75-g servings of milkfish, silver pomfret, or tilapia a day. Our analysis indicates that the DHA level recommended for childbearing women can be attained through fish consumption alone, without the need for supplementation and without posing a risk to the woman (or the fetus) from mercury.

Effects of salinity on growth and ion regulation of juvenile alligator gar Atractosteus spatula.

PubMed

Schwarz, Daniel E; Allen, Peter J

2014-03-01

The alligator gar (Atractosteus spatula) is a primitive euryhaline fish, found primarily in estuaries and freshwater drainages associated with the northern Gulf of Mexico. The extent of its hypo-osmotic regulatory abilities is not well understood. In order to determine how salinity affects growth rates and ionic and osmoregulation, juvenile alligator gar (330 days after hatch; 185 g) were exposed to 4 different salinities (0, 8, 16, and 24 ppt) for a 30-day period. Specific growth rate, plasma osmolality and ion concentrations, gill and gastrointestinal tract Na(+), K(+)-ATPase activities, and drinking rate were compared. Juvenile alligator gar were able to tolerate hyperosmotic salinities up to 24 ppt for a 30 day period, albeit with decreased growth resulting largely from decreased food consumption. Plasma osmolality and ionic concentrations were elevated in hyperosmotic salinities, and drinking rates and gastrointestinal tract Na(+), K(+)-ATPase activities increased, particularly in the pyloric caeca, presumably the primary location of water absorption. Therefore, juvenile alligator gar<1 year of age are capable of prolonged exposure to hyperosmotic salinities, but, based on the inference of these data, require access to lower salinities for long-term survival. Copyright © 2013 Elsevier Inc. All rights reserved.

Fish as Hosts of Vibrio cholerae.

PubMed

Halpern, Malka; Izhaki, Ido

2017-01-01

Vibrio cholerae , the causative agent of pandemic cholera, is abundant in marine and freshwater environments. Copepods and chironomids are natural reservoirs of this species. However, the ways V. cholerae is globally disseminated are as yet unknown. Here we review the scientific literature that provides evidence for the possibility that some fish species may be reservoirs and vectors of V. cholerae . So far, V. cholerae has been isolated from 30 fish species (22 freshwater; 9 marine). V. cholerae O1 was reported in a few cases. In most cases V. cholerae was isolated from fish intestines, but it has also been detected in gills, skin, kidney, liver and brain tissue. In most cases the fish were healthy but in some, they were diseased. Nevertheless, Koch postulates were not applied to prove that V. cholerae and not another agent was the cause of the disease in the fish. Evidence from the literature correlates raw fish consumption or fish handling to a few cholera cases or cholera epidemics. Thus, we can conclude that V. cholerae inhabits some marine and freshwater fish species. It is possible that fish may protect the bacteria in unfavorable habitats while the bacteria may assist the fish to digest its food. Also, fish may disseminate the bacteria in the aquatic environment and may transfer it to waterbirds that consume them. Thus, fish are reservoirs of V. cholerae and may play a role in its global dissemination.

Fish as Hosts of Vibrio cholerae

PubMed Central

Halpern, Malka; Izhaki, Ido

2017-01-01

Vibrio cholerae, the causative agent of pandemic cholera, is abundant in marine and freshwater environments. Copepods and chironomids are natural reservoirs of this species. However, the ways V. cholerae is globally disseminated are as yet unknown. Here we review the scientific literature that provides evidence for the possibility that some fish species may be reservoirs and vectors of V. cholerae. So far, V. cholerae has been isolated from 30 fish species (22 freshwater; 9 marine). V. cholerae O1 was reported in a few cases. In most cases V. cholerae was isolated from fish intestines, but it has also been detected in gills, skin, kidney, liver and brain tissue. In most cases the fish were healthy but in some, they were diseased. Nevertheless, Koch postulates were not applied to prove that V. cholerae and not another agent was the cause of the disease in the fish. Evidence from the literature correlates raw fish consumption or fish handling to a few cholera cases or cholera epidemics. Thus, we can conclude that V. cholerae inhabits some marine and freshwater fish species. It is possible that fish may protect the bacteria in unfavorable habitats while the bacteria may assist the fish to digest its food. Also, fish may disseminate the bacteria in the aquatic environment and may transfer it to waterbirds that consume them. Thus, fish are reservoirs of V. cholerae and may play a role in its global dissemination. PMID:28293221

Effect of species, life stage, and water temperature on the toxicity of hydrogen peroxide to fish

USGS Publications Warehouse

Rach, J.J.; Schreier, Theresa M.; Howe, G.E.; Redman, S.D.

1997-01-01

Hydrogen peroxide is a drug of low regulatory priority status that is effective in treating fish and fish eggs infected by fungi. However, only limited information is available to guide fish culturists in administering hydrogen peroxide to diseased fish. Laboratory tests were conducted to determine (1) the sensitivity of brown trout Salmo trutta, lake trout Salvelinus namaycush, fathead minnow Pimephales promelas, walleye Stizostedion vitreum, channel catfish Ictalurus punctatus, and bluegill Lepomis, machrochirus to hydrogen peroxide treatments; (2) the sensitivity of various life stages of rainbow trout Oncorhynchus mykiss to hydrogen peroxide treatments; and (3) the effect of water temperature on the acute toxicity of hydrogen peroxide to three fish species. Fish were exposed to hydrogen peroxide concentrations ranging from 100 to 5,000 mu L/L (ppm) for 15-min or 45-min treatments every other day for four consecutive treatments to determine the sensitivity of various species and life stages of fish. Except for walleye, most species of fish tested (less than or equal to 2 g) tolerated hydrogen peroxide of 1,000 mu L/L or greater. Walleyes were sensitive to hydrogen peroxide concentrations as low as 100 mu L/L. A correlation was found between the toxicity of hydrogen peroxide and the life stages of rainbow trout; larger fish were more sensitive. Generally, the toxicity of hydrogen peroxide increased for all species as water temperature increased. The results of these experiments demonstrate that it is important to consider the effects of species, life stage, and water temperature when conducting hydrogen peroxide treatments.

Fish Assemblages Associated with Natural and Anthropogenically-Modified Habitats in a Marine Embayment: Comparison of Baited Videos and Opera-House Traps

PubMed Central

Wakefield, Corey B.; Lewis, Paul D.; Coutts, Teresa B.; Fairclough, David V.; Langlois, Timothy J.

2013-01-01

Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment) and modified (rockwall and dredge channel) habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet) for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment. PMID:23555847

Fish assemblages associated with natural and anthropogenically-modified habitats in a marine embayment: comparison of baited videos and opera-house traps.

PubMed

Wakefield, Corey B; Lewis, Paul D; Coutts, Teresa B; Fairclough, David V; Langlois, Timothy J

2013-01-01

Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment) and modified (rockwall and dredge channel) habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet) for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment.

Resource partitioning within major bottom fish species in a highly productive upwelling ecosystem

NASA Astrophysics Data System (ADS)

Abdellaoui, Souad; El Halouani, Hassan; Tai, Imane; Masski, Hicham

2017-09-01

The Saharan Bank (21-26°N) is a wide subtropical continental shelf and a highly productive upwelling ecosystem. The bottom communities are dominated by octopus and sparid fish, which are the main targets of bottom-trawl fishing fleets. To investigate resource partitioning within the bottom fish community, adult fish from 14 of the most abundant species were investigated for stomach content analysis. Samples were collected during two periods: October 2003 and May 2007. The diet of the analysed species showed more variation between periods than between size classes, suggesting that temporal or spatial variability in prey availability appears to play a significant role in their diet. Multivariate analysis and subsequent clustering led to a grouping of the species within five trophic guilds. Two species were fish feeders, and the others mainly fed on benthic invertebrates, where epibenthic crustaceans, lamellibranchs and fish were the most important groups in defining trophic guilds. We found that the studied species had a high rate of overlapping spatial distributions and overlapping trophic niches. In this highly productive upwelling ecosystem, where food resources may not be a limiting factor, inter-specific competition did not appear to be an important factor in structuring bottom fish communities. For the species that showed differences in the proportions of prey categories in comparison with other ecosystems, the rise of the proportion of epibenthic crustaceans in their diet was a common feature; a possible consequence of the benthic productivity of this highly productive upwelling ecosystem.

Life History Correlates and Extinction Risk of Capital-Breeding Fishes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jager, Yetta; Vila-Gispert, Dr Anna; Rose, Kenneth A.

2008-03-01

We consider a distinction for fishes, often made for birds and reptiles, between capital-breeding and income-breeding species. Species that follow a capital-breeding strategy tend to evolve longer intervals between reproductive events and tend to have characteristics that we associate with higher extinction risk. To examine whether these ideas are relevant for fishes, we assembled life-history data for fish species, including an index of extinction risk, the interval between spawning events, the degree of parental care, and whether or not the species migrates to spawn. These data were used to evaluate two hypotheses: 1) fish species with a major accessory activitymore » to spawning (migration or parental care) spawn less often and 2) fish species that spawn less often are at greater risk of extinction. We tested these hypotheses by applying two alternative statistical methods that account for phylogenetic correlation in cross-taxon comparisons. The two methods predicted average intervals between spawning events 0.13 to 0.20 years longer for fishes with a major accessory activity. Both accessories, above-average parental care and spawning migration, were individually associated with longer average spawning intervals. We conclude that the capital-breeding paradigm is relevant for fishes. We also confirmed the second hypothesis, that species in higher IUCN extinction risk categories had longer average spawning intervals. Further research is needed to understand the relationship between extinction risk and spawning interval, within the broader context of life history traits and aquatic habitats.« less

Functional feeding traits as predictors of invasive success of alien freshwater fish species using a food-fish model.

PubMed

Nagelkerke, Leopold A J; van Onselen, Eline; van Kessel, Nils; Leuven, Rob S E W

2018-01-01

Invasions of Ponto-Caspian fish species into north-western European river basins accelerated since the opening of the Rhine-Main-Danube Canal in 1992. Since 2002, at least five Ponto-Caspian alien fish species have arrived in The Netherlands. Four species belong to the Gobiidae family (Neogobius fluviatilis, Neogobius melanostomus, Ponticola kessleri, and Proterorhinus semilunaris) and one to the Cyprinidae family (Romanogobio belingi). These species are expected to be potentially deleterious for the populations of four native benthic fish species: Gobio gobio (Cyprinidae), Barbatula barbatula (Nemacheilidae), Cottus perifretum, and C. rhenanus (Cottidae). Invasion success may be dependent on competitive trophic interactions with native species, which are enabled and/or constrained by feeding-related morphological traits. Twenty-two functional feeding traits were measured in nine species (in total 90 specimens). These traits were quantitatively linked to the mechanical, chemical and behavioral properties of a range of aquatic resource categories, using a previously developed food-fish model (FFM). The FFM was used to predict the trophic profile (TP) of each fish: the combined capacities to feed on each of the resource types. The most extreme TPs belonged to three alien species, indicating that they were most specialized among the studied species. Of these three, only P. kessleri overlapped with the two native Cottus species, indicating potential trophic competition. N. fluviatilis and R. belingi did not show any overlap, indicating that there is low trophic competition. The two remaining alien goby species (N. melanostomus and P. semilunaris) had average TPs and could be considered generalist feeders. They overlapped with each other and with G. gobio and B. barbatula, indicating potential trophic competition. This study suggests that both generalist and specialist species can be successful invaders. Since the FFM predicts potential interactions between species, it provides a tool to support horizon scanning and rapid risk assessments of alien species.

9 CFR 93.914 - Declaration and other documents.

Code of Federal Regulations, 2013 CFR

2013-01-01

...; the origin of the live fish; the number, species, and the purpose of the importation; the name of the...; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Aquatic Animal Species General Provisions for Vhs-Regulated Fish Species § 93.914 Declaration and other documents. (a) For live VHS-regulated fish offered for...

9 CFR 93.914 - Declaration and other documents.

Code of Federal Regulations, 2012 CFR

2012-01-01

...; the origin of the live fish; the number, species, and the purpose of the importation; the name of the...; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Aquatic Animal Species General Provisions for Vhs-Regulated Fish Species § 93.914 Declaration and other documents. (a) For live VHS-regulated fish offered for...

9 CFR 93.914 - Declaration and other documents.

Code of Federal Regulations, 2014 CFR

2014-01-01

...; the origin of the live fish; the number, species, and the purpose of the importation; the name of the...; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Aquatic Animal Species General Provisions for Vhs-Regulated Fish Species § 93.914 Declaration and other documents. (a) For live VHS-regulated fish offered for...

9 CFR 93.914 - Declaration and other documents.

Code of Federal Regulations, 2011 CFR

2011-01-01

...; the origin of the live fish; the number, species, and the purpose of the importation; the name of the...; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Aquatic Animal Species General Provisions for Vhs-Regulated Fish Species § 93.914 Declaration and other documents. (a) For live VHS-regulated fish offered for...

9 CFR 93.914 - Declaration and other documents.

Code of Federal Regulations, 2010 CFR

2010-01-01

...; the origin of the live fish; the number, species, and the purpose of the importation; the name of the...; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Aquatic Animal Species General Provisions for Vhs-Regulated Fish Species § 93.914 Declaration and other documents. (a) For live VHS-regulated fish offered for...

RNA-Seq identifies SNPs associated with muscle yield and quality in rainbow trout

USDA-ARS?s Scientific Manuscript database

Rainbow trout (Oncorhynchus mykiss) is one of the top five sport fish species in North America and the second most widely cultivated fish species for food. Quality attributes of fish flesh are important determinants of profitability for the food fish aquaculture industry. Single nucleotide polymorph...

50 CFR 622.48 - Adjustment of management measures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of the applicable FMPs, the RA may establish or modify the following items: (a) Caribbean coral reef..., and essential fish habitat HAPCs or Coral HAPCs. (d) Gulf reef fish. (1) For a species or species..., coral reefs, and live/hard bottom habitats. Definitions of essential fish habitat and essential fish...

Total and Methyl Mercury in 1994-5 Lake Michigan Lake Trout and Forage Fish

EPA Science Inventory

Total and methyl mercury were analyzed in Lake Michigan fish collected in 1994 and 1995 as part of the Lake Michigan Mass Balance project (LMMB). One predator fish species and five forage fish species were analyzed to determine the bioaccumulative nature of mercury. These data ...

75 FR 76400 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-08

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service, National.... 1531-1543) and regulations governing listed fish and wildlife permits (50 CFR parts 222-226). NMFS.... In the four studies described below, researchers do not expect to kill any listed fish but a small...

75 FR 50746 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-17

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS.... 1531 et seq.) and regulations governing listed fish and wildlife permits (50 CFR Parts 222-226). NMFS... is to evaluate factors limiting fish distribution and water quality in streams owned by PBF. The...

77 FR 63294 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-16

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Klallam Tribe and the Washington Department of Fish and Wildlife have submitted five Hatchery and Genetic... programs are currently operating, and all five hatchery programs raise fish native to the Elwha River basin...

76 FR 20956 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-14

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... 1973 (16 U.S.C. 1531-1543) and regulations governing listed fish and wildlife permits (50 CFR Parts 222... the two projects described below, Dr. Bartholomew and her co-investigators will utilize fish obtained...

75 FR 56986 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-17

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations governing listed fish and wildlife permits (50 CFR 222-226). NMFS issues permits based on findings.... Applications Received Permit 15549 The Columbia River Inter-Tribal Fish Commission (CRITFC) is seeking a five...

75 FR 14134 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-24

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS..., CA (14685, 14688), and California Department of Fish and Game (CDFG), North Central Region 2, in... to the ESA and NMFS regulations governing listed fish and wildlife permits (50 CFR parts 222-226...

78 FR 43858 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-22

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... number of predicted adults increase, the number of fish escaping to the spawning grounds will also... fish; and (3) application of a sliding scale approach to determine appropriate ESA take limits on...

76 FR 61344 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-04

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... to the ESA and NMFS regulations (50 CFR parts 222-226) governing listed fish and wildlife permits... fish captured. Permit 15824 does not authorize any non- lethal or lethal take of adult ESA-listed...

76 FR 8713 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... (16 U.S.C. 1531-1543) and regulations governing listed fish and wildlife permits (50 CFR parts 222-226... handling of fish is already covered under the Incidental Take Statement associated with the Biological...

75 FR 78226 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-15

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... accordance with and are subject to the ESA and NMFS regulations governing listed fish and wildlife permits... steelhead while conducting fish monitoring surveys in lower Putah Creek, a tributary in the Sacramento River...

75 FR 22738 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-30

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... seq.) and regulations governing listed fish and wildlife permits (50 CFR 222-226). NMFS issues permits... of toxicants). The KWIAHT would capture fish (using beach seines); measure them; check them for marks...

76 FR 67121 - Atlantic Highly Migratory Species; 2012 Atlantic Shark Commercial Fishing Season

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-31

.... 110913585-1625-01] RIN 0648-BB36 Atlantic Highly Migratory Species; 2012 Atlantic Shark Commercial Fishing... establish opening dates and adjust quotas for the 2012 fishing season for the Atlantic commercial shark... 2011 Atlantic commercial shark fishing seasons. In addition, NMFS proposes season openings based on...

Seasonal investigation of trace element contents in commercially valuable fish species from the Black sea, Turkey.

PubMed

Mendil, Durali; Demirci, Zafer; Tuzen, Mustafa; Soylak, Mustafa

2010-03-01

Fish species (Sarda sarda, Mulus barbatus ponticus, Trachurus trachurus and Merlangius merlangus) were collected from the Black sea, Turkey between 2008 and 2009 (spring, summer, autumn and winter). The samples were analyzed using flame and graphite furnace atomic absorption spectrometry after microwave digestion. The maximum metal concentrations were found to be as 25.5-41.4 microg/g (Fe), 17.8-25.7 microg/g (Zn), 0.28-0.64 microg/g (Pb), 0.64-0.99 microg/g (Cr), 1.3-3.6 microg/g (Mn), 1.4-1.9 microg/g (Cu), 0.18-0.35 microg/g (Cd) and 0.25-0.42 microg/g (Co) for fish species. The concentration of trace metals in samples is depended on fish species. Some species is accumulated trace metals at high ratio. Trace element levels in analyzed fish species were acceptable to human consumption at nutritional and toxic levels. The levels of lead and cadmium in fish samples were higher than the recommended legal limits. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

A regional perspective on the diversity and conservation of tropical Andean fishes.

PubMed

Anderson, Elizabeth P; Maldonado-Ocampo, Javier A

2011-02-01

The tropical Andes harbor an extraordinarily varied concentration of species in a landscape under increasing pressure from human activities. Conservation of the region's native plants and animals has received considerable international attention, but the focus has been on terrestrial biota. The conservation of freshwater fauna, particularly the conservation of fishes, has not been emphasized. Tropical Andean fishes are among the most understudied vertebrates in the world. We estimate that between 400 and 600 fish species inhabit the diverse aquatic environments in the region. Nearly 40% of these species are endemic. Tropical Andean fishes are vulnerable to ongoing environmental changes related to deforestation, water withdrawals, water pollution, species introductions, and hydropower development. Additionally, their distributions and population dynamics may be affected by hydrologic alterations and warmer water temperatures associated with projected climate change. Presently, at least three species are considered extinct, some populations are endangered, and some species are likely to decline or disappear. The long-term persistence of tropical Andean fishes will depend on greater consideration of freshwater systems in regional conservation initiatives. ©2010 Society for Conservation Biology.

Spatial variations in fish-tissue mercury concentrations in the St. Croix River basin, Minnesota and Wisconsin, 2004

USGS Publications Warehouse

Christensen, Victoria G.; Wente, Stephen P.; Sandheinrich, Mark B.; Brigham, Mark E.

2006-01-01

Using the model to predict fish-tissue mercury concentrations allows site-specific fish-consumption advisories to be developed for multiple species and different lengths of fish. Potential mercury exposure to fish consumers may be reduced because an individual can choose to consume sizes and species of fish that are expected to have lower fish-tissue mercury concentrations. The National Park Service can use these results to more reliably monitor fish-tissue mercury concentrations in the St. Croix River Basin and better assess potential health effects of fish consumption to humans and wildlife.

76 FR 2663 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-14

... Conservation Bank on the Sacramento River in the Central Valley, California. Permit 13675 authorizes indirect... species, taking of length measurements), tissue sampling, release of moribund fish or fish carcasses back...

Opportunism or aquatic specialization? Evidence of freshwater fish exploitation at Ohalo II- A waterlogged Upper Paleolithic site

PubMed Central

Dayan, Tamar; Goren, Menachem; Nadel, Dani; Hershkovitz, Israel

2018-01-01

Analysis of ca. 17,000 fish remains recovered from the late Upper Paleolithic/early Epi-Paleolithic (LGM; 23,000 BP) waterlogged site of Ohalo II (Rift Valley, Israel) provides new insights into the role of wetland habitats and the fish inhabiting them during the evolution of economic strategies prior to the agricultural evolution. Of the current 19 native fish species in Lake Kinneret (Sea of Galilee), eight species were identified at Ohalo II, belonging to two freshwater families: Cyprinidae (carps) and Cichlidae (St. Peter fish). Employing a large set of quantitative and qualitative criteria (NISP, species richness, diversity, skeletal element representation, fragmentation, color, spatial distribution, etc.), we demonstrate that the inhabitants of Ohalo II used their knowledge of the breeding behavior of different species of fish, for year-round intensive exploitation. PMID:29912923

Opportunism or aquatic specialization? Evidence of freshwater fish exploitation at Ohalo II- A waterlogged Upper Paleolithic site.

PubMed

Zohar, Irit; Dayan, Tamar; Goren, Menachem; Nadel, Dani; Hershkovitz, Israel

2018-01-01

Analysis of ca. 17,000 fish remains recovered from the late Upper Paleolithic/early Epi-Paleolithic (LGM; 23,000 BP) waterlogged site of Ohalo II (Rift Valley, Israel) provides new insights into the role of wetland habitats and the fish inhabiting them during the evolution of economic strategies prior to the agricultural evolution. Of the current 19 native fish species in Lake Kinneret (Sea of Galilee), eight species were identified at Ohalo II, belonging to two freshwater families: Cyprinidae (carps) and Cichlidae (St. Peter fish). Employing a large set of quantitative and qualitative criteria (NISP, species richness, diversity, skeletal element representation, fragmentation, color, spatial distribution, etc.), we demonstrate that the inhabitants of Ohalo II used their knowledge of the breeding behavior of different species of fish, for year-round intensive exploitation.

Fish depth distributions in the Lower Mississippi River

USGS Publications Warehouse

Killgore, K. J.; Miranda, Leandro E.

2014-01-01

A substantial body of literature exists about depth distribution of fish in oceans, lakes and reservoirs, but less is known about fish depth distribution in large rivers. Most of the emphasis on fish distributions in rivers has focused on longitudinal and latitudinal spatial distributions. Knowledge on depth distribution is necessary to understand species and community habitat needs. Considering this void, our goal was to identify patterns in fish benthic distribution along depth gradients in the Lower Mississippi River. Fish were collected over 14 years in depths down to 27 m. Fish exhibited non-random depth distributions that varied seasonally and according to species. Species richness was highest in shallow water, with about 50% of the 62 species detected no longer collected in water deeper than 8 m and about 75% no longer collected in water deeper than 12 m. Although richness was highest in shallow water, most species were not restricted to shallow water. Rather, most species used a wide range of depths. A weak depth zonation occurred, not as strong as that reported for deep oceans and lakes. Larger fish tended to occur in deeper water during the high-water period of an annual cycle, but no correlation was evident during the low-water period. The advent of landscape ecology has guided river research to search for spatial patterns along the length of the river and associated floodplains. Our results suggest that fish assemblages in large rivers are also structured vertically. 

The fishes of Pea Ridge National Military Park, Arkansas, 2003

USGS Publications Warehouse

Justus, B.G.; Petersen, James C.

2005-01-01

A fish inventory was conducted at Pea Ridge National Military Park, Arkansas, during base-flow conditions in September 2003. Six sites including four streams and two ponds were sampled using conventional electrofishing equipment (a seine also was used at one site). There were 653 individuals collected comprising 18 species (plus 1 hybrid) and 15 genera. The number of species collected at the four stream sites ranged from 1 16. Most fish species collected generally are associated with small streams in the Ozark Plateaus. The two most common species were the banded sculpin and the southern redbelly dace. Three species and a sunfish hybrid were collected from the quarry pond. No fish were collected from the unnamed pond. A preliminary expected species list incorrectly listed 42 species because of incorrect species range or habitat requirements. One species not on the original list was added to the revised list. Upon revising this list, the inventory yielded 18 the 40 species (45 percent) and 1 hybrid. No previous fish inventories have been completed for park but some observations can be made relative to species distributions. There were only five fish species collected in three headwater streams, and it is unlikely that many other species would occur in these three streams because of constraints imposed on the fish community by stream size. Little Sugar Creek, a medium-sized stream, had the most species collected, and it is likely that additional species would be collected from this stream if additional sampling were to occur. Distribution records indicate that all 18 species occur in the general area. Although no species collected in this study are federallylisted threatened or endangered species, three species collected at Pea Ridge National Military Park may be of some special interest to National Park Service managers and others. Two the species collected (cardinal shiner and stippled darter) are endemic to the Ozark Plateaus; both are rather common in certain parts of the Ozark Plateaus. The white sucker has a restricted range in Arkansas because northern Arkansas is at southern edge of the white sucker's distributional range.

Distribution and chemical form of mercury in commercial fish tissues.

PubMed

Watanabe, Naoko; Tayama, Misato; Inouye, Minoru; Yasutake, Akira

2012-01-01

We analyzed total Hg concentrations in various tissue samples obtained from 7 commercially available fish species. MeHg contents were also estimated for muscle and liver samples by a selective analysis of inorganic Hg. Among the tissues, high Hg accumulations were shown in liver, muscle, heart and spleen throughout all fish species. Carnivorous fish, such as scorpion fish, sea bream and Japanese whiting, tended to show higher Hg accumulations in the muscle, with the highest Hg levels being shown by scorpion fish. Although the liver was expected to show the highest Hg accumulations among tissues throughout all fish species, the highest accumulation in the liver was observed only in scorpion fish. In contrast, the muscle level was significantly higher than the liver in Pacific saury and Japanese whiting. MeHg accumulated in fish is considered to show a sustained increase throughout the life of the fish, due to its long biological half-life. In fact, in the present study, muscle Hg levels in Japanese whiting, Japanese flying fish, and halfbeak showed good correlations with body weights. However, such correlations were not clear in scorpion fish, sea bream, Jack mackerel and Pacific saury. Selective analyses of inorganic Hg levels revealed that most of the Hg (> 95%) in fish muscle existed as MeHg, while the rates of MeHg contents in the liver varied from 56% in scorpion fish to 84% in Jack mackerel. As a result, fish muscle showed the highest MeHg accumulations in all fish species examined. These results suggest that reliable information on total Hg contents in fish muscle might be sufficient to avoid the risk of MeHg exposure caused by eating fish, even when one consumes other tissues such as fish liver.

Fish communities and the nursery role of the shallow inshore waters of a tropical bay in the gulf of Carpentaria, Australia

NASA Astrophysics Data System (ADS)

Blaber, S. J. M.; Brewer, D. T.; Salini, J. P.

The species composition of the fishes of the inshore zone between a tropical estuary and offshore trawling grounds were studied. The objectives were to investigate the affinities of the fishes with those of adjacent areas, to examine the influence of abiotic factors on species composition, and to assess the role and importance of the zone as a nursery area. The shallow (<5 m) inshore waters south of the Embley estuary were sampled in two wet, two dry and two pre-wet seasons between 1989 and 1993. A total of 7934 fish of 118 species were caught with gill nets (5741 individuals of 95 species) and beach seines (2193 individuals of 45 species). Forty-two of the species caught have not been reported in the adjacent offshore prawn or fish trawling grounds, 32 species have not been found in the nearby Embley estuary, and 15 species were caught only in the inshore zone. The dominant species caught by gill netting in the inshore zone were Scomberoides commersonianus (5.47 g m -1 h -1), Chanos chanos (3.67 g m -1 h -1) and Eleutheronema tetradactylum (3.57 g m -1 h -1). Overall, fish catch rates and biomasses were less than in the adjacent estuary and offshore waters, but greater than in tropical sea-grass localities. The number of species in the inshore zone (118) is less than in the Embley estuary (197), the clear inshore waters of Groote Eylandt in the western Gulf of Carpentaria (156) and in the offshore waters (237), but greater than in the Norman estuary (100). These differences are probably due to habitat diversity. Water turbidity, tidal range, wind and day versus night were the only abiotic factors that correlated with the relative abundances of some species. The inshore zone acts as a nursery for many species and is the first nursery ground for at least 11 species whose adults live mainly offshore. The overall juvenile component of the inshore fauna consists of fishes apparently restricted to the inshore habitat, larger juveniles that have emigrated from the estuary, and fish that occur in all three habitats. The inshore zone is not primarily or solely a transition zone between estuary and offshore. It is a habitat with characteristic juvenile and adult fish communities, but it supports some fish that move between offshore and estuarine habitats. It is also an important spawning area for some species as well as a foraging zone for a number of piscivores.

Habitat Specialization in Tropical Continental Shelf Demersal Fish Assemblages

PubMed Central

Fitzpatrick, Ben M.; Harvey, Euan S.; Heyward, Andrew J.; Twiggs, Emily J.; Colquhoun, Jamie

2012-01-01

The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304) collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1–10 m depth), down the fore reef slope to the reef base (10–30 m depth) then across the adjacent continental shelf (30–110 m depth). Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category) were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of connected habitats through which fish can migrate. PMID:22761852

Diversity in migratory patterns among Neotropical fishes in a highly regulated river basin.

PubMed

Makrakis, M C; Miranda, L E; Makrakis, S; Fontes Júnior, H M; Morlis, W G; Dias, J H P; Garcia, J O

2012-07-01

Migratory behaviour of selected fish species is described in the Paraná River, Brazil-Argentina-Paraguay, to search for patterns relevant to tropical regulated river systems. In a 10 year mark-recapture study, spanning a 1425 km section of the river, 32 867 fishes composed of 18 species were released and 1083 fishes were recaptured. The fishes recaptured were at liberty an average 166 days (maximum 1548 days) and travelled an average 35 km (range 0-625 km). Cluster analysis applied to variables descriptive of movement behaviour identified four general movement patterns. Cluster 1 included species that moved long distances (mean 164 km) upstream (54%) and downstream (40%) the mainstem river and showed high incidence (27%) of passage through dams; cluster 2 also exhibited high rate of movement along the mainstem (49% upstream, 13% downstream), but moved small distances (mean 10 km); cluster 3 included the most fishes moving laterally into tributaries (45%) or not moving at all (25%), but little downstream movement (8%); fishes in cluster 4 exhibited little upstream movement (13%) and farthest downstream movements (mean 41 km). Whereas species could be numerically clustered with statistical models, a species ordination showed ample spread, suggesting that species exhibit diverse movement patterns that cannot be easily classified into just a few classes. The cluster and ordination procedures also showed that adults and juveniles of the same species exhibit similar movement patterns. Conventional concepts about Neotropical migratory fishes portray them as travelling long distances upstream. The present results broaden these concepts suggesting that migratory movements are more diverse, could be long, short or at times absent, upriver, downriver or lateral, and the diversity of movements can vary within and among species. The intense lateral migrations exhibited by a diversity of species, especially to and from large tributaries (above reservoirs) and reservoir tributaries, illustrate the importance of these habitats for the fish species life cycle. Considering that the Paraná River is highly impounded, special attention should be given to the few remaining low-impact habitats as they continue to be targets of hydropower development that will probably intensify the effects on migratory fish stocks. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Evolution of Venomous Cartilaginous and Ray-Finned Fishes.

PubMed

Smith, W Leo; Stern, Jennifer H; Girard, Matthew G; Davis, Matthew P

2016-11-01

Venom and its associated delivery systems have evolved in numerous animal groups ranging from jellyfishes to spiders, lizards, shrews, and the male platypus. Building off new data and previously published anatomical and molecular studies, we explore the evolution of and variation within venomous fishes. We show the results of the first multi-locus, ordinal-level phylogenetic analysis of cartilaginous (Chondrichthyes) and ray-finned (Actinopterygii) fishes that hypothesizes 18 independent evolutions of this specialization. Ancestral-states reconstruction indicates that among the 2386-2962 extant venomous fishes, envenomed structures have evolved four times in cartilaginous fishes, once in eels (Anguilliformes), once in catfishes (Siluriformes), and 12 times in spiny-rayed fishes (Acanthomorpha). From our anatomical studies and phylogenetic reconstruction, we show that dorsal spines are the most common envenomed structures (∼95% of venomous fish species and 15 independent evolutions). In addition to envenomed spines, fishes have also evolved venomous fangs (2% of venomous fish species, two independent evolutions), cleithral spines (2% of venomous fish species, one independent evolution), and opercular or subopercular spines (1% of venomous fish species, three independent evolutions). © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Identification of estuarine fish Dormitator latifrons as an intermediate host and Eleotris picta as a paratenic host for Gnathostoma binucleatum in Sinaloa, Mexico.

PubMed

Díaz-Camacho, Sylvia Páz; de la Cruz-Otero, Ma Del Carmen; Zazueta-Ramos, Magda Luz; Bojórquez-Contreras, Angel; Sicairos-Félix, Josefina; Campista-León, Samuel; Guzmán-Loreto, Roberto; Delgado-Vargas, Francisco; León-Règagnon, Virginia; Nawa, Yukifumi

2008-11-01

Gnathostomosis is a typical fish-borne zoonotic parasitosis and is currently a serious public health issue in Mexico. Among several Gnathostoma species present in wild animals in Mexico, Gnathostoma binucleatum is the only proven species responsible for human diseases, and the advanced third stage larvae (AL3) of G. binucleatum have been found in over 20 species of fish in this country. In Sinaloa State, two fish species, Dormitator latifrons and Eleotris picta, were heavily contaminated with G. binucleatum AL3. When we analyzed the relationship between the size of the fish and the density of infection with G. binucleatum AL3, the distribution patterns of AL3 were markedly different between these two fish species. Apparent size-dependent accumulation was observed in E. picta but not in D. latifrons, suggesting that E. picta is a paratenic host whereas D. latifrons is a second intermediate host.

The uptake of macroplastic & microplastic by demersal & pelagic fish in the Northeast Atlantic around Scotland.

PubMed

Murphy, Fionn; Russell, Marie; Ewins, Ciaran; Quinn, Brian

2017-09-15

This study reports plastic ingestion in various fish found from coastal and offshore sites in Scottish marine waters. Coastal samples consisted of three demersal flatfish species (n=128) collected from the East and West coasts of Scotland. Offshore samples consisted of 5 pelagic species and 4 demersal species (n=84) collected from the Northeast Atlantic. From the coastal fish sampled, 47.7% of the gastrointestinal tracts contained macroplastic and microplastic. Of the 84 pelagic and demersal offshore fish, only 2 (2.4%) individuals from different species had ingested plastic identified as a clear polystyrene fibre and a black polyamide fibre. The average number of plastic items found per fish from all locations that had ingested plastic was 1.8 (±1.7) with polyamide (65.3%), polyethylene terephthalate (14.4%) and acrylic (14.4%) being the three most commonly found plastics. This study adds to the existing data on macroplastic and microplastic ingestion in fish species. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Inventory of marine and estuarine fishes in southeast and central Alaska National Parks

USGS Publications Warehouse

Arimitsu, Mayumi L.; Litzow, Michael A.; Piatt, John F.; Robards, Martin D.; Abookire, Alisa A.; Drew, Gary S.

2003-01-01

As part of a national inventory program funded by the National Park Service, we conducted an inventory of marine and estuarine fishes in Glacier Bay National Park and Preserve, Wrangell-St. Elias National Park and Preserve, Sitka National Historical Park, and Klondike Gold Rush National Historical Park in 2001 and 2002. In addition, marine fish data from a previous project that focused on forage fishes and marine predators during 1999 and 2000 in Glacier Bay proper were compiled for this study. Sampling was conducted with modified herring and Isaacs-Kidd midwater trawls, a plumb staff beam trawl, and beach seines. Species lists of relative abundance were generated for nearshore fishes in all parks, and for demersal and pelagic fishes in Glacier Bay National Park and Preserve and Wrangell-St. Elias National Park and Preserve. With a total sampling effort of 531 sets, we captured 100 species in Glacier Bay National Park and Preserve, 31 species in Wrangell-St. Elias National Park and Preserve, 23 species in Sitka National Historical Park, and 11 species in Klondike Gold Rush National Historical Park. We estimated that between 59 and 85 percent of the total marine fish species present were sampled by us in the various habitat-park units. We also combined these data with historical records and prepared an annotated species list of 160 marine and estuarine fishes known to occur in Glacier Bay National Park and Preserve. Shannon-Wiener diversity index and catch per unit effort were used to assess the effects of depth and latitude (distance from tidewater glaciers) on marine fish community ecology in Glacier Bay proper. Our findings suggest that demersal fishes are more abundant and diverse with increased distance from tidewater glaciers, and that pelagic fishes sampled deeper than 50 m are more abundant in areas closer to tidewater glaciers.

Tropical fishes dominate temperate reef fish communities within western Japan.

PubMed

Nakamura, Yohei; Feary, David A; Kanda, Masaru; Yamaoka, Kosaku

2013-01-01

Climate change is resulting in rapid poleward shifts in the geographical distribution of tropical and subtropical fish species. We can expect that such range shifts are likely to be limited by species-specific resource requirements, with temperate rocky reefs potentially lacking a range of settlement substrates or specific dietary components important in structuring the settlement and success of tropical and subtropical fish species. We examined the importance of resource use in structuring the distribution patterns of range shifting tropical and subtropical fishes, comparing this with resident temperate fish species within western Japan (Tosa Bay); the abundance, diversity, size class, functional structure and latitudinal range of reef fishes utilizing both coral reef and adjacent rocky reef habitat were quantified over a 2 year period (2008-2010). This region has undergone rapid poleward expansion of reef-building corals in response to increasing coastal water temperatures, and forms one of the global hotspots for rapid coastal changes. Despite the temperate latitude surveyed (33°N, 133°E) the fish assemblage was both numerically, and in terms of richness, dominated by tropical fishes. Such tropical faunal dominance was apparent within both coral, and rocky reef habitats. The size structure of the assemblage suggested that a relatively large number of tropical species are overwintering within both coral and rocky habitats, with a subset of these species being potentially reproductively active. The relatively high abundance and richness of tropical species with obligate associations with live coral resources (i.e., obligate corallivores) shows that this region holds the most well developed temperate-located tropical fish fauna globally. We argue that future tropicalisation of the fish fauna in western Japan, associated with increasing coral habitat development and reported increasing shifts in coastal water temperatures, may have considerable positive economic impacts to the local tourism industry and bring qualitative changes to both local and regional fisheries resources.

Tropical Fishes Dominate Temperate Reef Fish Communities within Western Japan

PubMed Central

Nakamura, Yohei; Feary, David A.; Kanda, Masaru; Yamaoka, Kosaku

2013-01-01

Climate change is resulting in rapid poleward shifts in the geographical distribution of tropical and subtropical fish species. We can expect that such range shifts are likely to be limited by species-specific resource requirements, with temperate rocky reefs potentially lacking a range of settlement substrates or specific dietary components important in structuring the settlement and success of tropical and subtropical fish species. We examined the importance of resource use in structuring the distribution patterns of range shifting tropical and subtropical fishes, comparing this with resident temperate fish species within western Japan (Tosa Bay); the abundance, diversity, size class, functional structure and latitudinal range of reef fishes utilizing both coral reef and adjacent rocky reef habitat were quantified over a 2 year period (2008–2010). This region has undergone rapid poleward expansion of reef-building corals in response to increasing coastal water temperatures, and forms one of the global hotspots for rapid coastal changes. Despite the temperate latitude surveyed (33°N, 133°E) the fish assemblage was both numerically, and in terms of richness, dominated by tropical fishes. Such tropical faunal dominance was apparent within both coral, and rocky reef habitats. The size structure of the assemblage suggested that a relatively large number of tropical species are overwintering within both coral and rocky habitats, with a subset of these species being potentially reproductively active. The relatively high abundance and richness of tropical species with obligate associations with live coral resources (i.e., obligate corallivores) shows that this region holds the most well developed temperate-located tropical fish fauna globally. We argue that future tropicalisation of the fish fauna in western Japan, associated with increasing coral habitat development and reported increasing shifts in coastal water temperatures, may have considerable positive economic impacts to the local tourism industry and bring qualitative changes to both local and regional fisheries resources. PMID:24312528

Invasion of the Upper Mississippi River System by Saltwater Amphipods

EPA Science Inventory

Zoobenthos surveys of the Great Rivers of the Upper Mississippi River basin (Missouri, Mississippi, and Ohio Rivers) provided an opportunity for documenting a series of invasions by euryhaline amphipods. The corophiid amphipod Apocorophium lacustre was first found in the Ohio Ri...

Latitudinal variation in the shape of the species body size distribution: an analysis using freshwater fishes.

PubMed

Knouft, Jason H

2004-05-01

Many taxonomic and ecological assemblages of species exhibit a right-skewed body size-frequency distribution when characterized at a regional scale. Although this distribution has been frequently described, factors influencing geographic variation in the distribution are not well understood, nor are mechanisms responsible for distribution shape. In this study, variation in the species body size-frequency distributions of 344 regional communities of North American freshwater fishes is examined in relation to latitude, species richness, and taxonomic composition. Although the distribution of all species of North American fishes is right-skewed, a negative correlation exists between latitude and regional community size distribution skewness, with size distributions becoming left-skewed at high latitudes. This relationship is not an artifact of the confounding relationship between latitude and species richness in North American fishes. The negative correlation between latitude and regional community size distribution skewness is partially due to the geographic distribution of families of fishes and apparently enhanced by a nonrandom geographic distribution of species within families. These results are discussed in the context of previous explanations of factors responsible for the generation of species size-frequency distributions related to the fractal nature of the environment, energetics, and evolutionary patterns of body size in North American fishes.

Fish-T1K (Transcriptomes of 1,000 Fishes) Project: large-scale transcriptome data for fish evolution studies.

PubMed

Sun, Ying; Huang, Yu; Li, Xiaofeng; Baldwin, Carole C; Zhou, Zhuocheng; Yan, Zhixiang; Crandall, Keith A; Zhang, Yong; Zhao, Xiaomeng; Wang, Min; Wong, Alex; Fang, Chao; Zhang, Xinhui; Huang, Hai; Lopez, Jose V; Kilfoyle, Kirk; Zhang, Yong; Ortí, Guillermo; Venkatesh, Byrappa; Shi, Qiong

2016-01-01

Ray-finned fishes (Actinopterygii) represent more than 50 % of extant vertebrates and are of great evolutionary, ecologic and economic significance, but they are relatively underrepresented in 'omics studies. Increased availability of transcriptome data for these species will allow researchers to better understand changes in gene expression, and to carry out functional analyses. An international project known as the "Transcriptomes of 1,000 Fishes" (Fish-T1K) project has been established to generate RNA-seq transcriptome sequences for 1,000 diverse species of ray-finned fishes. The first phase of this project has produced transcriptomes from more than 180 ray-finned fishes, representing 142 species and covering 51 orders and 109 families. Here we provide an overview of the goals of this project and the work done so far.

Fish is Fish: the use of experimental model species to reveal causes of skeletal diversity in evolution and disease

PubMed Central

Harris, M. P.; Henke, K.; Hawkins, M. B.; Witten, P. E.

2014-01-01

Summary Fishes are wonderfully diverse. This variety is a result of the ability of ray-finned fishes to adapt to a wide range of environments, and has made them more specious than the rest of vertebrates combined. With such diversity it is easy to dismiss comparisons between distantly related fishes in efforts to understand the biology of a particular fish species. However, shared ancestry and the conservation of developmental mechanisms, morphological features and physiology provide the ability to use comparative analyses between different organisms to understand mechanisms of development and physiology. The use of species that are amenable to experimental investigation provides tools to approach questions that would not be feasible in other ‘non-model’ organisms. For example, the use of small teleost fishes such as zebrafish and medaka has been powerful for analysis of gene function and mechanisms of disease in humans, including skeletal diseases. However, use of these fish to aid in understanding variation and disease in other fishes has been largely unexplored. This is especially evident in aquaculture research. Here we highlight the utility of these small laboratory fishes to study genetic and developmental factors that underlie skeletal malformations that occur under farming conditions. We highlight several areas in which model species can serve as a resource for identifying the causes of variation in economically important fish species as well as to assess strategies to alleviate the expression of the variant phenotypes in farmed fish. We focus on genetic causes of skeletal deformities in the zebrafish and medaka that closely resemble phenotypes observed both in farmed as well as natural populations of fishes. PMID:25221374

The Application of Traits-Based Assessment Approaches to Estimate the Effects of Hydroelectric Turbine Passage on Fish Populations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cada, Glenn F; Schweizer, Peter E

One of the most important environmental issues facing the hydropower industry is the adverse impact of hydroelectric projects on downstream fish passage. Fish that migrate long distances as part of their life cycle include not only important diadromous species (such as salmon, shads, and eels) but also strictly freshwater species. The hydropower reservoirs that downstream-moving fish encounter differ greatly from free-flowing rivers. Many of the environmental changes that occur in a reservoir (altered water temperature and transparency, decreased flow velocities, increased predation) can reduce survival. Upon reaching the dam, downstream-migrating fish may suffer increased mortality as they pass through themore » turbines, spillways and other bypasses, or turbulent tailraces. Downstream from the dam, insufficient environmental flow releases may slow downstream fish passage rates or decrease survival. There is a need to refine our understanding of the relative importance of causative factors that contribute to turbine passage mortality (e.g., strike, pressure changes, turbulence) so that turbine design efforts can focus on mitigating the most damaging components. Further, present knowledge of the effectiveness of turbine improvements is based on studies of only a few species (mainly salmon and American shad). These data may not be representative of turbine passage effects for the hundreds of other fish species that are susceptible to downstream passage at hydroelectric projects. For example, there are over 900 species of fish in the United States. In Brazil there are an estimated 3,000 freshwater fish species, of which 30% are believed to be migratory (Viana et al. 2011). Worldwide, there are some 14,000 freshwater fish species (Magurran 2009), of which significant numbers are susceptible to hydropower impacts. By comparison, in a compilation of fish entrainment and turbine survival studies from over 100 hydroelectric projects in the United States, Winchell et al. (2000) found useful turbine passage survival data for only 30 species. Tests of advanced hydropower turbines have been limited to seven species - Chinook and coho salmon, rainbow trout, alewife, eel, smallmouth bass, and white sturgeon. We are investigating possible approaches for extending experimental results from the few tested fish species to predict turbine passage survival of other, untested species (Cada and Richmond 2011). In this report, we define the causes of injury and mortality to fish tested in laboratory and field studies, based on fish body shape and size, internal and external morphology, and physiology. We have begun to group the large numbers of unstudied species into a small number of categories, e.g., based on phylogenetic relationships or ecological similarities (guilds), so that subsequent studies of a few representative species (potentially including species-specific Biological Index Testing) would yield useful information about the overall fish community. This initial effort focused on modifying approaches that are used in the environmental toxicology field to estimate the toxicity of substances to untested species. Such techniques as the development of species sensitivity distributions (SSDs) and Interspecies Correlation Estimation (ICE) models rely on a considerable amount of data to establish the species-toxicity relationships that can be extended to other organisms. There are far fewer studies of turbine passage stresses from which to derive the turbine passage equivalent of LC{sub 50} values. Whereas the SSD and ICE approaches are useful analogues to predicting turbine passage injury and mortality, too few data are available to support their application without some form of modification or simplification. In this report we explore the potential application of a newer, related technique, the Traits-Based Assessment (TBA), to the prediction of downstream passage mortality at hydropower projects.« less

75 FR 76302 - Atlantic Highly Migratory Species; 2011 Commercial Fishing Season and Adaptive Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-08

... fish for sharks in the summer presents a safety-at-sea issue as it is dangerous in the Florida summer... shark fishermen who do not want to fish in the heat of the summer, or who fish for other species in the summer, an opportunity to fish during the cooler months. Gulf of Mexico Region Comment 7: Shark meat is...

Development of a spatially distributed model of fish population density for habitat assessment of rivers

NASA Astrophysics Data System (ADS)

Sui, Pengzhe; Iwasaki, Akito; Ryo, Masahiro; Saavedra, Oliver; Yoshimura, Chihiro

2013-04-01

Flow conditions play an important role in sustaining biodiversity of river ecosystem. However, their relations to freshwater fishes, especially to fish population density, have not been clearly described. This study, therefore, aimed to propose a new methodology to quantitatively link habitat conditions, including flow conditions and other physical conditions, to population density of fish species. We developed a basin-scale fish distribution model by integrating the concept of habitat suitability assessment with a distributed hydrological model (DHM) in order to estimate fish population density with particular attention to flow conditions. Generalized linear model (GLM) was employed to evaluate the relationship between population density of fish species and major environmental factors. The target basin was Sagami River in central Japan, where the river reach was divided into 10 sections by estuary, confluences of tributaries, and river-crossing structures (dams, weirs). The DHM was employed to simulate river discharge from 1998 to 2005, which was used to calculate 10 flow indices including mean discharge, 25th and 75th percentile discharge, duration of low and high flows, number of floods. In addition, 5 water quality parameters and 13 other physical conditions (such as basin area, river width, mean diameter of riverbed material, and number of river-crossing structures upstream and downstream) of each river section were considered as environmental variables. In case of Sagami River, 10 habitat variables among them were then selected based on their correlations to avoid multicollinearity. Finally, the best GLM was developed for each species based on Akaike's information criterion. As results, population densities of 16 fish species in Sagami River were modelled, and correlation coefficients between observed and calculated population densities for 10 species were more than 0.70. The key habitat factors for population density varied among fish species. Minimum discharge (MID) was found to be positively correlated to 9 among 16 fish species. For duration of high and low flows (DHF and DLF), longer DHF/DLF was corresponded to lower population density for 7/6 fish species, respectively, such as Rhinogobius kurodai and Plecoglossus altivelis altivelis. Among physical habitat conditions, sinuosity index (SI, the ratio between actual river section length and straight line length) seems to be the most important parameter for fish population density in Sagami River basin, since it affects 12 out of 16 fish species, followed by mean longitudinal slope (S) and number of downstream dams (NLD). Above results demonstrated the applicability of fish distribution model to provide quantitative information on flow conditions required to maintain fish population, which enabled us to evaluate and project ecological consequences of water resource management policy, such as flood management and water withdrawal.

Study of the cross-reactivity of fish allergens based on a questionnaire and blood testing.

PubMed

Kobayashi, Yukihiro; Huge, Jiletu; Imamura, Shintaro; Hamada-Sato, Naoko

2016-07-01

Parvalbumin and collagen have been identified as cross-reactive allergens for fish allergies. Although doctors realize that various fish elicit allergies, the targets of food allergen labeling laws were only mackerels and salmons in Japan and mackerels in South Korea. This study aimed to reveal the causative species for fish allergy via questionnaires and blood tests. Questionnaire research was conducted in Japan via the internet concerning allergies for fish-allergic patients or their family members. Next, IgE reactivities and cross-reactivities of 26 fish species were analyzed using sera obtained from 16 Japanese patients who were allergic to fish parvalbumin or collagen by enzyme-linked immunosorbent assay (ELISA) and inhibition ELISA. Questionnaire research revealed that 88% patients cannot eat mackerel and salmon in addition to other fish. In addition, 85% respondents were not satisfied with the current food allergen labeling law. In ELISA analyses, we clarified that pooled serum obtained from patients with fish parvalbumin-specific allergies exhibited IgE reactivity to the extracts of most fish species, and pooled serum obtained from patients with fish collagen-specific allergies displayed IgE reactivity to the extracts of all types of fish. Inhibition ELISA experiments revealed cross-reactivities of parvalbumin or collagen to extracts from all fish tested. Most patients with fish allergies displayed allergic symptoms following the intake of various fish species. In addition, fish parvalbumin and collagen were causative factors of fish allergy and were highly cross-reactive fish panallergens. Therefore, current laws should be revised in Japan and South Korea. Copyright © 2016 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

Stability and generalization in seed dispersal networks: a case study of frugivorous fish in Neotropical wetlands.

PubMed

Correa, Sandra Bibiana; Arujo, Joisiane K; Penha, Jerry; Nunes da Cunha, Catia; Bobier, Karen E; Anderson, Jill T

2016-08-31

When species within guilds perform similar ecological roles, functional redundancy can buffer ecosystems against species loss. Using data on the frequency of interactions between fish and fruit, we assessed whether co-occurring frugivores provide redundant seed dispersal services in three species-rich Neotropical wetlands. Our study revealed that frugivorous fishes have generalized diets; however, large-bodied fishes had greater seed dispersal breadth than small species, in some cases, providing seed dispersal services not achieved by smaller fish species. As overfishing disproportionately affects big fishes, the extirpation of these species could cause larger secondary extinctions of plant species than the loss of small specialist frugivores. To evaluate the consequences of frugivore specialization for network stability, we extracted data from 39 published seed dispersal networks of frugivorous birds, mammals and fish (our networks) across ecosystems. Our analysis of interaction frequencies revealed low frugivore specialization and lower nestedness than analyses based on binary data (presence-absence of interactions). In that case, ecosystems may be resilient to loss of any given frugivore. However, robustness to frugivore extinction declines with specialization, such that networks composed primarily of specialist frugivores are highly susceptible to the loss of generalists. In contrast with analyses of binary data, recently developed algorithms capable of modelling interaction strengths provide opportunities to enhance our understanding of complex ecological networks by accounting for heterogeneity of frugivore-fruit interactions. © 2016 The Author(s).

Stability and generalization in seed dispersal networks: a case study of frugivorous fish in Neotropical wetlands

PubMed Central

Arujo, Joisiane K.; Penha, Jerry; Nunes da Cunha, Catia

2016-01-01

When species within guilds perform similar ecological roles, functional redundancy can buffer ecosystems against species loss. Using data on the frequency of interactions between fish and fruit, we assessed whether co-occurring frugivores provide redundant seed dispersal services in three species-rich Neotropical wetlands. Our study revealed that frugivorous fishes have generalized diets; however, large-bodied fishes had greater seed dispersal breadth than small species, in some cases, providing seed dispersal services not achieved by smaller fish species. As overfishing disproportionately affects big fishes, the extirpation of these species could cause larger secondary extinctions of plant species than the loss of small specialist frugivores. To evaluate the consequences of frugivore specialization for network stability, we extracted data from 39 published seed dispersal networks of frugivorous birds, mammals and fish (our networks) across ecosystems. Our analysis of interaction frequencies revealed low frugivore specialization and lower nestedness than analyses based on binary data (presence–absence of interactions). In that case, ecosystems may be resilient to loss of any given frugivore. However, robustness to frugivore extinction declines with specialization, such that networks composed primarily of specialist frugivores are highly susceptible to the loss of generalists. In contrast with analyses of binary data, recently developed algorithms capable of modelling interaction strengths provide opportunities to enhance our understanding of complex ecological networks by accounting for heterogeneity of frugivore–fruit interactions. PMID:27581879

Evaluating analytical approaches for estimating pelagic fish biomass using simulated fish communities

USGS Publications Warehouse

Yule, Daniel L.; Adams, Jean V.; Warner, David M.; Hrabik, Thomas R.; Kocovsky, Patrick M.; Weidel, Brian C.; Rudstam, Lars G.; Sullivan, Patrick J.

2013-01-01

Pelagic fish assessments often combine large amounts of acoustic-based fish density data and limited midwater trawl information to estimate species-specific biomass density. We compared the accuracy of five apportionment methods for estimating pelagic fish biomass density using simulated communities with known fish numbers that mimic Lakes Superior, Michigan, and Ontario, representing a range of fish community complexities. Across all apportionment methods, the error in the estimated biomass generally declined with increasing effort, but methods that accounted for community composition changes with water column depth performed best. Correlations between trawl catch and the true species composition were highest when more fish were caught, highlighting the benefits of targeted trawling in locations of high fish density. Pelagic fish surveys should incorporate geographic and water column depth stratification in the survey design, use apportionment methods that account for species-specific depth differences, target midwater trawling effort in areas of high fish density, and include at least 15 midwater trawls. With relatively basic biological information, simulations of fish communities and sampling programs can optimize effort allocation and reduce error in biomass estimates.

Altitudinal variation in fish assemblage diversity in streams of the central Andes of Colombia.

PubMed

Jaramillo-Villa, U; Maldonado-Ocampo, J A; Escobar, F

2010-06-01

This study documents differences in fish assemblages for 32 freshwater streams located between 258 and 2242 m a.s.l. on the eastern slopes of the central range of the Colombian Andes. A total of 2049 fishes belonging to 62 species, 34 genera and 16 families were collected. Species richness declined rapidly with altitude; nearly 90% of the species were recorded between 250 and 1250 m a.s.l. Three of the four physico-chemical variables, of the water, temperature, dissolved oxygen and pH, explained 53.5% of the variation in species richness along the altitudinal gradient, with temperature the most important (37.6%). An analysis of species composition showed that the distinctiveness of the fish fauna increased with elevation, with the greatest turnover observed between 1000 and 1750 m a.s.l. On this altitudinal gradient, turnover was dominated by the loss of species rather than gain, and dominance by just a few species was greater at higher elevations. Turnover was also observed along the altitudinal gradient in the structure of the three functional groups (torrential, pool and pelagic species). The study focused on understanding the pattern of diversity of fish communities inhabiting the Andes in Colombia. Anthropogenic effects on the altitudinal distribution of fish species in the region, however, are largely unknown and would require further investigations.

Host specificity and the structure of helminth parasite communities of fishes in a Neotropical river in Mexico.

PubMed

Salgado-Maldonado, Guillermo; Novelo-Turcotte, María Teresa; Caspeta-Mandujano, Juan Manuel; Vazquez-Hurtado, Gabriela; Quiroz-Martínez, Benjamin; Mercado-Silva, Norman; Favila, Mario

2016-01-01

In a tropical locality of Río La Antigua, Veracruz, Mexico, 11 fish species, represented by 244 individual fish from six freshwater fish families living sympatrically and synchronically, were examined for helminth parasites. A total of 36 taxa of helminths were recorded, 24 autogenic and 12 allogenic forms, including 6 monogeneans, 14 trematodes, 1 cestode, and 15 nematodes. Most helminth taxa were recovered for 10/11 of the component communities we analyzed. The results contribute empirical evidence that host specificity is an important force in the development of helminth communities of freshwater fishes. Each fish family has their own set of parasites, host species belonging to the same taxon share parasite species. High component community similarity among related host species was recorded, demonstrated by high prevalence and abundance, as well as dominance, of autogenic specialist species in each component community. Most autogenic helminth species are numerically and reproductively successful in relatively few host species. Autogenic helminths common in one host species are not common in others. Our findings give empirical support to the idea that low levels of sharing of parasites favor animal coexistence and high species richness, because large phylogenetic differences allow potentially competing animals to consume the same resources without being sensitive of another's parasites. © G. Salgado-Maldonado et al., published by EDP Sciences, 2016.

Comparative energetics of the 5 fish classes on the basis of dynamic energy budgets

NASA Astrophysics Data System (ADS)

Kooijman, Sebastiaan A. L. M.; Lika, Konstadia

2014-11-01

The eco-physiology of taxa in an evolutionary context can best be studied by a comparison of parameter values of the energy budget that accounts for the inter-relationships of all endpoints of energy allocation. To this end, the parameters of the standard Dynamic Energy Budget (DEB) model have been estimated for 64 fish species from all 5 fish classes. The values are compared with those of the whole collection of over 300 species from most large animal phyla. The goodness of fit was very high, but the data were rather incomplete, compared with the energy balance for full life cycles. Metabolic acceleration, where maximum specific assimilation and energy conductance increase with length between birth and metabolic metamorphosis, seems to be confined, among fish, to some species of ray-finned fish and seems to have evolved independently several times in this taxon. We introduce a new altriciality index, i.e. the ratio of the maturity levels at puberty and birth, and conclude that ray-finned fish are more altricial, and cartilaginous fish are more precocial than typical animals. Fish allocate more to reproduction than typical animals. Parameter estimates show that 66% of the fish species considered invest less in reproduction than the value that would maximize the reproduction rate of fully grown individuals. By comparison, 85% of all the animal species in the collection do so. Consistent with theoretical expectations, allocation to reproduction and maturity at birth increase with cubed (ultimate structural) length, and reserve capacity with length for non-ray-finned fish, with the consequence that reproduction rate decreases with length. Ray-finned fish, however, have a maturity at birth and a reserve capacity almost independent of length, and a reproduction rate that increases with cubed length. Reserve capacity tends to increase with ultimate length for non-accelerating ray-finned fish, but not for accelerating species. Reproduction rate decreases inter-specifically with length in non-ray-finned fish, as expected, but increases with cubed length in ray-finned fish. This pattern follows naturally from the patterns of size at birth and reserve capacity and can be seen as adaptation to the predation of prey of ray-finned fish on their tiny neonates. Both the von Bertalanffy growth rate and the specific allocation to reproduction in fully grown adults correlate positively with specific somatic maintenance among fish species. These observations support the recently proposed waste-to-hurry hypothesis. Determinatesness increases in the sequence: fish, amphibians, reptiles, mammals and birds.

Resolution of fish allergy: a case report.

PubMed

Solensky, Roland

2003-10-01

Fish allergy is one of the most common food allergies, and it is believed to be lifelong. There are no published reports, to my knowledge, of resolution of fish allergy. To report a case of resolution of IgE-mediated fish allergy. The patient was a 68-year-old man with a history of fish-induced anaphylaxis who had previously undergone prick-puncture skin testing to several fish species. Additional skin testing was performed in October 2002. Subsequently, he underwent an open challenge with halibut. The patient's previous skin tests showed him to have strongly positive reactions to several fish species. However, testing performed in October 2002 produced negative results to a number of fish species. In addition, he tolerated an open challenge with halibut. In the ensuing 8 months, he has regularly ingested salmon, cod, and halibut without experiencing any allergic reactions. This case illustrates that fish allergy is not invariably lifelong. Hence, allergists should consider reevaluating the allergy status of adults with a history of fish hypersensitivity.

Genotoxicity of freshwater ecosystem shows DNA damage in preponderant fish as validated by in vivo micronucleus induction in gill and kidney erythrocytes.

PubMed

Obiakor, M O; Okonkwo, J C; Ezeonyejiaku, C D

2014-12-01

Genotoxicity of Anambra River was studied by micronucleus (MN) assay of preponderant fish species in the river. The micronucleus indices obtained were used as biomarker to estimate and predict pollution profile and possible danger of feeding on the aquatic species. Micronuclei profile of the fish was measured from gill and kidney erythrocytes using microscopic technique. Season, species and location effects on micronuclei, together with their interactions were also determined. Two major seasons (rainy and dry) and preponderant fish species in the river (Synodontis clarias, Linnaeus, 1758 and Tilapia nilotica, Linnaeus, 1757) were studied at five distinct locations that displayed differential environmental stresses. The study showed that the micronucleus index of fish is an excellent biomarker for measuring pollution level and genotoxicity of freshwater habitat. Season, species of fish and location affect micronuclei profile of the fish species sampled in the river. Disease outbreak among rural dwellers depending on the river for domestic and other uses is imminent and they lack knowledge on its health implication. Moreover, the study maintained that the micronuclei in fish could be measured from either the gill or kidney; however, gill is more efficient as it enables collection of several samples from the same individuals without sacrificing it, and Synodontis clarias fish species appeared to be more vulnerable to the genotoxic damage than Tilapia nilotica. Consequently, the study recommended regular monitoring (micronucleus tests) of edible aquatic life such as Synodontis clarias in order to eliminate the danger of people feeding on toxic metals, some of which are carcinogenic. Copyright © 2014 Elsevier B.V. All rights reserved.

Description, microhabitat selection and infection patterns of sealworm larvae (Pseudoterranova decipiens species complex, nematoda: ascaridoidea) in fishes from Patagonia, Argentina.

PubMed

Hernández-Orts, Jesús S; Aznar, Francisco J; Blasco-Costa, Isabel; García, Néstor A; Víllora-Montero, María; Crespo, Enrique A; Raga, Juan A; Montero, Francisco E

2013-08-29

Third-stage larvae of the Pseudoterranova decipiens species complex (also known as sealworms) have been reported in at least 40 marine fish species belonging to 21 families and 10 orders along the South American coast. Sealworms are a cause for concern because they can infect humans who consume raw or undercooked fish. However, despite their economic and zoonotic importance, morphological and molecular characterization of species of Pseudoterranova in South America is still scarce. A total of 542 individual fish from 20 species from the Patagonian coast of Argentina were examined for sealworms. The body cavity, the muscles, internal organs, and the mesenteries were examined to detect nematodes. Sealworm larvae were removed from their capsules and fixed in 70% ethanol. For molecular identification, partial fragments of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) were amplified for 10 isolates from 4 fish species. Morphological and morphometric data of sealworms were also obtained. A total of 635 larvae were collected from 12 fish species. The most infected fish was Prionotus nudigula, followed by Percophis brasiliensis, Acanthistius patachonicus, Paralichthys isosceles, and Pseudopercis semifasciata. Sequences obtained for the cox1 of sealworms from A. patachonicus, P. isosceles, P. brasiliensis and P. nudigula formed a reciprocally monophyletic lineage with published sequences of adult specimens of Pseudoterranova cattani from the South American sea lion Otaria flavescens, and distinct from the remaining 5 species of Pseudoterranova. A morphological description, including drawings and scanning electron microscopy photomicrographs of these larvae is provided. Sealworms collected from Argentinean fishes did not differ in their diagnostic traits from the previously described larvae of P. cattani. However a discriminant analysis suggests that specimens from P. nudigula were significantly larger than those from other fishes. Most of the sealworms were collected encapsulated from the muscles and, to a lesser degree, from the mesenteries and the liver. We provided the first molecular identification, morphological description and microhabitat characterization of sealworm larvae from the Argentinean Patagonian coast. We also reported the infection levels of sealworms on 20 fish species in order to elucidate the life cycle of these nematodes in this area.

Description, microhabitat selection and infection patterns of sealworm larvae (Pseudoterranova decipiens species complex, nematoda: ascaridoidea) in fishes from Patagonia, Argentina

PubMed Central

2013-01-01

Background Third-stage larvae of the Pseudoterranova decipiens species complex (also known as sealworms) have been reported in at least 40 marine fish species belonging to 21 families and 10 orders along the South American coast. Sealworms are a cause for concern because they can infect humans who consume raw or undercooked fish. However, despite their economic and zoonotic importance, morphological and molecular characterization of species of Pseudoterranova in South America is still scarce. Methods A total of 542 individual fish from 20 species from the Patagonian coast of Argentina were examined for sealworms. The body cavity, the muscles, internal organs, and the mesenteries were examined to detect nematodes. Sealworm larvae were removed from their capsules and fixed in 70% ethanol. For molecular identification, partial fragments of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) were amplified for 10 isolates from 4 fish species. Morphological and morphometric data of sealworms were also obtained. Results A total of 635 larvae were collected from 12 fish species. The most infected fish was Prionotus nudigula, followed by Percophis brasiliensis, Acanthistius patachonicus, Paralichthys isosceles, and Pseudopercis semifasciata. Sequences obtained for the cox1 of sealworms from A. patachonicus, P. isosceles, P. brasiliensis and P. nudigula formed a reciprocally monophyletic lineage with published sequences of adult specimens of Pseudoterranova cattani from the South American sea lion Otaria flavescens, and distinct from the remaining 5 species of Pseudoterranova. A morphological description, including drawings and scanning electron microscopy photomicrographs of these larvae is provided. Sealworms collected from Argentinean fishes did not differ in their diagnostic traits from the previously described larvae of P. cattani. However a discriminant analysis suggests that specimens from P. nudigula were significantly larger than those from other fishes. Most of the sealworms were collected encapsulated from the muscles and, to a lesser degree, from the mesenteries and the liver. Conclusions We provided the first molecular identification, morphological description and microhabitat characterization of sealworm larvae from the Argentinean Patagonian coast. We also reported the infection levels of sealworms on 20 fish species in order to elucidate the life cycle of these nematodes in this area. PMID:23988009

78 FR 60766 - Endangered and Threatened Wildlife and Plants; Threatened Species Status for Spring Pygmy Sunfish

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R4-ES-2012... Pygmy Sunfish AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule. SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine threatened species status under the Endangered Species...

50 CFR 222.309 - Permits for listed species of sea turtles involving the Fish and Wildlife Service.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Permits for listed species of sea turtles involving the Fish and Wildlife Service. 222.309 Section 222.309 Wildlife and Fisheries NATIONAL MARINE... species of sea turtles involving the Fish and Wildlife Service. (a) This section establishes specific...

50 CFR 222.309 - Permits for listed species of sea turtles involving the Fish and Wildlife Service.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Permits for listed species of sea turtles involving the Fish and Wildlife Service. 222.309 Section 222.309 Wildlife and Fisheries NATIONAL MARINE... species of sea turtles involving the Fish and Wildlife Service. (a) This section establishes specific...

50 CFR 222.309 - Permits for listed species of sea turtles involving the Fish and Wildlife Service.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Permits for listed species of sea turtles involving the Fish and Wildlife Service. 222.309 Section 222.309 Wildlife and Fisheries NATIONAL MARINE... species of sea turtles involving the Fish and Wildlife Service. (a) This section establishes specific...

50 CFR 222.309 - Permits for listed species of sea turtles involving the Fish and Wildlife Service.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Permits for listed species of sea turtles involving the Fish and Wildlife Service. 222.309 Section 222.309 Wildlife and Fisheries NATIONAL MARINE... species of sea turtles involving the Fish and Wildlife Service. (a) This section establishes specific...

50 CFR 222.309 - Permits for listed species of sea turtles involving the Fish and Wildlife Service.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Permits for listed species of sea turtles involving the Fish and Wildlife Service. 222.309 Section 222.309 Wildlife and Fisheries NATIONAL MARINE... species of sea turtles involving the Fish and Wildlife Service. (a) This section establishes specific...

Iberian fish records in the vertebrate collection of the Museum of Zoology of the University of Navarra

PubMed Central

Rodeles, Amaia A.; Galicia, David; Miranda, Rafael

2016-01-01

The study of freshwater fish species biodiversity and community composition is essential for understanding river systems, the effects of human activities on rivers, and the changes these animals face. Conducting this type of research requires quantitative information on fish abundance, ideally with long-term series and fish body measurements. This Data Descriptor presents a collection of 12 datasets containing a total of 146,342 occurrence records of 41 freshwater fish species sampled in 233 localities of various Iberian river basins. The datasets also contain 148,749 measurement records (length and weight) for these fish. Data were collected in different sampling campaigns (from 1992 to 2015). Eleven datasets represent large projects conducted over several years, and another combines small sampling campaigns. The Iberian Peninsula contains high fish biodiversity, with numerous endemic species threatened by various menaces, such as water extraction and invasive species. These data may support the development of large biodiversity conservation studies. PMID:27727236

Evaluation of Trace Metal Levels in Tissues of Two Commercial Fish Species in Kapar and Mersing Coastal Waters, Peninsular Malaysia

PubMed Central

Bashir, Fathi Alhashmi; Shuhaimi-Othman, Mohammad; Mazlan, A. G.

2012-01-01

This study is focused on evaluating the trace metal levels in water and tissues of two commercial fish species Arius thalassinus and Pennahia anea that were collected from Kapar and Mersing coastal waters. The concentrations of Fe, Zn, Al, As, Cd and Pb in these coastal waters and muscle, liver and gills tissues of the fishes were quantified. The relationship among the metal concentrations and the height and weight of the two species were also examined. Generally, the iron has the highest concentrations in both water and the fish species. However, Cd in both coastal waters showed high levels exceeding the international standards. The metal level concentration in the sample fishes are in the descending order livers > gills > muscles. A positive association between the trace metal concentrations and weight and length of the sample fishes was investigated. Fortunately the level of these metal concentrations in fish has not exceeded the permitted level of Malaysian and international standards. PMID:22046193

Occurrence of microplastics in the gastrointestinal tract of pelagic and demersal fish from the English Channel.

PubMed

Lusher, A L; McHugh, M; Thompson, R C

2013-02-15

Microplastics are present in marine habitats worldwide and laboratory studies show this material can be ingested, yet data on abundance in natural populations is limited. This study documents microplastics in 10 species of fish from the English Channel. 504 Fish were examined and plastics found in the gastrointestinal tracts of 36.5%. All five pelagic species and all five demersal species had ingested plastic. Of the 184 fish that had ingested plastic the average number of pieces per fish was 1.90±0.10. A total of 351 pieces of plastic were identified using FT-IR Spectroscopy; polyamide (35.6%) and the semi-synthetic cellulosic material, rayon (57.8%) were most common. There was no significant difference between the abundance of plastic ingested by pelagic and demersal fish. Hence, microplastic ingestion appears to be common, in relatively small quantities, across a range of fish species irrespective of feeding habitat. Further work is needed to establish the potential consequences. Copyright © 2012 Elsevier Ltd. All rights reserved.

Iberian fish records in the vertebrate collection of the Museum of Zoology of the University of Navarra.

PubMed

Rodeles, Amaia A; Galicia, David; Miranda, Rafael

2016-10-11

The study of freshwater fish species biodiversity and community composition is essential for understanding river systems, the effects of human activities on rivers, and the changes these animals face. Conducting this type of research requires quantitative information on fish abundance, ideally with long-term series and fish body measurements. This Data Descriptor presents a collection of 12 datasets containing a total of 146,342 occurrence records of 41 freshwater fish species sampled in 233 localities of various Iberian river basins. The datasets also contain 148,749 measurement records (length and weight) for these fish. Data were collected in different sampling campaigns (from 1992 to 2015). Eleven datasets represent large projects conducted over several years, and another combines small sampling campaigns. The Iberian Peninsula contains high fish biodiversity, with numerous endemic species threatened by various menaces, such as water extraction and invasive species. These data may support the development of large biodiversity conservation studies.

Sperm motility in fish: technical applications and perspectives through CASA-Mot systems.

PubMed

Gallego, V; Asturiano, J F

2018-03-09

Although a relatively high number of sperm quality biomarkers have been reported over the years in several fish species, sperm motility is nowadays considered the best biomarker for fish spermatozoa. The first scientific reports focusing on fish sperm motility date from a century ago, but the objective assessment allowed by computer-aided sperm analysis (CASA-Mot) systems was not applied to fish species until the mid-1980s. Since then, a high number of sperm kinetic parameters from more than 170 fish species have been reported in more than 700 scientific articles, covering a wide range of topics, such as sperm physiology, sperm storage, broodstock management, the phenomenon of sperm competition, ecotoxicology and understanding the life cycle of the species. The sperm kinetic parameters provided by CASA-Mot systems can serve as powerful and useful tools for aquaculture and ecological purposes, and this review provides an overview of the major research areas in which fish sperm motility assessment by a CASA-Mot system has been used successfully.

Factors influencing tropical island freshwater fishes:Species, status, and management implications in puerto rico [Factores que influencian a los peces tropicales de agua dulce: Especies, estado actual e implicaciones para el manejo en Puerto Rico

USGS Publications Warehouse

Wesley, Neal J.; Lilyestrom, Craig G.; Kwak, T.J.

2009-01-01

Anthropogenic effects including river regulation, watershed development, contamination, and fish introductions have substantially affected the majority of freshwater habitats in Europe and North America. This pattern of resource development and degradation is widespread in the tropics, and often little is known about the resources before they are lost. This article describes the freshwater resources of Puerto Rico and identifies factors that threaten conservation of native fishes. The fishes found in freshwater habitats of Puerto Rico represent a moderately diverse assemblage composed of 14 orders, 29 families, and 82 species. There are fewer than 10 species of native peripherally-freshwater fish that require a link to marine systems. Introductions of nonindigenous species have greatly expanded fish diversity in freshwater systems, and native estuarine and marine species (18 families) also commonly enter lowland rivers and brackish lagoons. Environmental alterations, including land use and development, stream channelization, pollution, and the impoundment of rivers, combined with nonnative species introductions threaten the health and sustainability of aquatic resources in Puerto Rico. Six principal areas for attention that are important influences on the current and future status of the freshwater fish resources of Puerto Rico are identified and discussed.

The post-larval and juvenile fish assemblage in the Sukhothai floodplain, Thailand

NASA Astrophysics Data System (ADS)

Siriwan, Suksri; Boonsatien, Boonsoong

2017-06-01

This study investigated abundance, species composition and spatial and temporal distributions of fish larvae and their relationship with some environmental variables in the Sukhothai floodplain in northern Thailand. Fish larvae were collected from 33 sampling stations on 8 occasions between August 2010 and October 2013. The study collected and identified 149 296 individuals, representing 32 families and 165 taxa. The species composition of larval fish was dominated by the Cyprinidae (47.27%), Cobitidae (7.88%), Siluridae (6.67%), Bagridae (6.06%) and Mastacembelidae (3.33%) families. The most-abundant larval species were the Striped flying barb Esomus metallicus (16.90%), the Siamese mud carp Henicorhynchus siamensis (8.48%) and the Sumatran river sprat Clupeichthys goniognathus (8.31%). The greatest abundance and species diversity of larvae were found when the river flow runs onto the floodplain. PCA and nMDS analysis revealed that the samples plot is associated with temporal distribution among years. The discharge was a major factor determining fish larvae assemblage and environmental variables in the Sukhothai floodplain. Four fish larval species were positively correlated with the samples for 2013. The result of the CCA ordination plot showed that only the discharge variable was strongly correlated with fish larvae abundance, especially two cyprinid Rasbora species.

DNA barcoding of freshwater fishes and the development of a quantitative qPCR assay for the species-specific detection and quantification of fish larvae from plankton samples.

PubMed

Loh, W K W; Bond, P; Ashton, K J; Roberts, D T; Tibbetts, I R

2014-08-01

The barcoding of mitochondrial cytochrome c oxidase subunit 1 (coI) gene was amplified and sequenced from 16 species of freshwater fishes found in Lake Wivenhoe (south-eastern Queensland, Australia) to support monitoring of reservoir fish populations, ecosystem function and water health. In this study, 630-650 bp sequences of the coI barcoding gene from 100 specimens representing 15 genera, 13 families and two subclasses of fishes allowed 14 of the 16 species to be identified and differentiated. The mean ± s.e. Kimura 2 parameter divergence within and between species was 0.52 ± 0.10 and 23.8 ± 2.20% respectively, indicating that barcodes can be used to discriminate most of the fish species accurately. The two terapontids, Amniataba percoides and Leiopotherapon unicolor, however, shared coI DNA sequences and could not be differentiated using this gene. A barcoding database was established and a qPCR assay was developed using coI sequences to identify and quantify proportional abundances of fish species in ichthyoplankton samples from Lake Wivenhoe. These methods provide a viable alternative to the time-consuming process of manually enumerating and identifying ichthyoplankton samples. © 2014 The Fisheries Society of the British Isles.

Using hierarchical Bayesian multi-species mixture models to estimate tandem hoop-net based habitat associations and detection probabilities of fishes in reservoirs

USGS Publications Warehouse

Stewart, David R.; Long, James M.

2015-01-01

Species distribution models are useful tools to evaluate habitat relationships of fishes. We used hierarchical Bayesian multispecies mixture models to evaluate the relationships of both detection and abundance with habitat of reservoir fishes caught using tandem hoop nets. A total of 7,212 fish from 12 species were captured, and the majority of the catch was composed of Channel Catfish Ictalurus punctatus (46%), Bluegill Lepomis macrochirus(25%), and White Crappie Pomoxis annularis (14%). Detection estimates ranged from 8% to 69%, and modeling results suggested that fishes were primarily influenced by reservoir size and context, water clarity and temperature, and land-use types. Species were differentially abundant within and among habitat types, and some fishes were found to be more abundant in turbid, less impacted (e.g., by urbanization and agriculture) reservoirs with longer shoreline lengths; whereas, other species were found more often in clear, nutrient-rich impoundments that had generally shorter shoreline length and were surrounded by a higher percentage of agricultural land. Our results demonstrated that habitat and reservoir characteristics may differentially benefit species and assemblage structure. This study provides a useful framework for evaluating capture efficiency for not only hoop nets but other gear types used to sample fishes in reservoirs.

9 CFR 93.903 - Import permits for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., fertilized eggs, and gametes. 93.903 Section 93.903 Animals and Animal Products ANIMAL AND PLANT HEALTH... General Provisions for Svc-Regulated Fish Species § 93.903 Import permits for live fish, fertilized eggs, and gametes. (a) Live fish, fertilized eggs, or gametes of SVC-susceptible species imported into the...

77 FR 33717 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-07

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... section 10(a)(1)(A) of the ESA of 1973 (16 U.S.C. 1531-1543) and regulations governing listed fish and... any listed fish, but a small number may die as an unintended result of the research activities...

76 FR 39856 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-07

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... accordance with and are subject to the ESA and NMFS regulations (50 CFR parts 222-226) governing listed fish... unintentional lethal take of: juvenile CCC steelhead not to exceed 3 percent of the total number of fish...

77 FR 76001 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-26

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations governing listed fish and wildlife permits(50 CFR parts 222-226). NMFS issues permits based on... described below, researchers do not expect to kill any listed fish but a small number may die as an...

76 FR 27016 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-10

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... governing listed fish and wildlife permits (50 CFR 222-226). NMFS issues permits based on findings that such... Received Permit 15611 The Washington Department of Fish and Wildlife (WDFW) is seeking a 5-year permit to...

76 FR 78242 - Endangered and Threatened Species; Take of Anadromous Fish

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-16

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS.... 1531 et. seq) and regulations governing listed fish and wildlife permits (50 CFR 222-226). NMFS issues... (USGS) is seeking to renew for five years a research permit that would allow them to take all fish...