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Sample records for acipenser fulvescens spawning

  1. Assessment of lake sturgeon (Acipenser fulvescens) spawning efforts in the lower St. Clair River, Michigan

    USGS Publications Warehouse

    Nichols, S. Jerrine; Kennedy, Gregory; Crawford, Eric; Allen, Jeffrey; French, John, III; Black, Glen; Blouin, Marc; Hickey, James P.; Chernyak, Sergei; Haas, Robert; Thomas, Michael

    2003-01-01

    One of the most threatened remaining populations of lake sturgeon in the Great Lakes is found in the connecting channels between Lake Huron and Lake Erie. Only two spawning grounds are presently known to be active in this region, and both are in the St. Clair River. The spawning reef in the St. Clair River delta has been recently colonized by round gobies (Neogobius melanostomus) in densities up to 25/m2, raising concerns regarding predation on the benthic-oriented eggs and larvae of the sturgeon. Investigations in 1998–1999 showed that while round goby predation does occur, a number of other factors may be equally affecting sturgeon spawning success, including few spawning adults (< 60), suspected poaching pressure, low retention rate of eggs on the reef, low hatch rate (~0.5%), the presence of organic contaminants, and predation from native and exotic invertebrates and fish. Overall, we estimate that less than 1% of the eggs deposited during a spawning run survive to hatch. We were able to increase the egg hatch rate to 16% by placing eggs in predator-exclusion chambers on the reef. The fate of the larvae is uncertain. Two weeks after hatching, no larvae were found on the reef. We were unable to find them anywhere else in the river, nor was predation on larvae noted in either year. There were factors other than predation affecting larval survival in 1999. There was a higher silt load on the reef than in 1998 and large numbers of dead larvae were found. Recruitment success from this site could be improved by utilizing techniques to increase the number of eggs on the reef, such as reducing the illegal take of adult fish and by placing eggs in predator-exclusion chambers to increase hatch rate.

  2. Environmental and lunar cues are predictive of the timing of river entry and spawning-site arrival in lake sturgeon Acipenser fulvescens.

    PubMed

    Forsythe, P S; Scribner, K T; Crossman, J A; Ragavendran, A; Baker, E A; Davis, C; Smith, K K

    2012-07-01

    The associations were quantified between daily and interannual variation in the timing of a closed population of lake sturgeon Acipenser fulvescens migration and arrival at spawning sites with stream environmental and lunar covariates. Spawning data were gathered from 1262 fish in Black Lake, Michigan 2001 to 2008 and by video monitoring 2000 to 2002. Sex-specific variation in responses to external cues was also tested. Results showed that a greater number of individuals initiated migration from lake to riverine habitats at dawn and dusk relative to other times of the day. Current and lagged effects of water temperature and river discharge, and periods in the lunar cycle were important variables in models quantifying movements into the river and timing of adult arrival at spawning sites. Different suites of covariates were predictive of A. fulverscens responses during different periods of the spawning season. The timing of initiation of migration and spawning, and the importance of covariates to the timing of these events, did not differ between sexes. Stream flow and temperature covaried with other variables including day length and the lunar cycle. Anthropogenic disruption of relationships among variables may mean that environmental cues may no longer reliably convey information for Acipenseriformes and other migratory fishes. PMID:22747803

  3. Verifying success of artificial spawning reefs in the St. Clair-Detroit River System for lake sturgeon (Acipenser fulvescens Rafinesque, 1817)

    USGS Publications Warehouse

    Bouckaert, Emliy K.; Auer, Nancy A.; Roseman, Edward F.; James Boase

    2014-01-01

    Lake sturgeon (Acipenser fulvescens) were historically abundant in the St. Clair – Detroit River System (SCDRS), a 160 km river/channel network. In the SCDRS, lake sturgeon populations have been negatively affected by the loss/degradation of natural spawning habitat. To address habitat loss for lake sturgeon and other species, efforts are underway to restore spawning substrate by constructing artificial reefs. The main objective of this study was to conduct post-construction monitoring of lake sturgeon egg deposition and larval emergence near two of these artificial reefs: Fighting Island Reef (FIR) in the Detroit River, and Middle Channel Reef in the St. Clair River. An additional site in the St. Clair River where lake sturgeon spawn on a coal clinker bed was also investigated. From 2010 to 2012, viable eggs and larvae were collected from all of these reefs, indicating that conditions are suitable for egg deposition, incubation, and larval emergence. In the St. Clair River, the results indicate the likelihood of other spawning sites upstream of these artificial reef sites.

  4. OBJECTIVE ANALYSIS OF SPERM MOTILITY IN THE LAKE STURGEON, ACIPENSER FULVESCENS: ACTIVATION AND INHIBITION CONDITIONS

    EPA Science Inventory

    An objective analysis of the duration of motility of sperm from the lake sturgeon, Acipenser fulvescens, has been performed using computer-assisted sperm motion analysis at 200 frames/s. Motility was measured in both 1993 and 1994. The percentage of activated motile sperm and the...

  5. EFFECT OF CRYOPRESERVATION AND THEOPHYLLINE ON MOTILITY CHARACTERISTICS OF LAKE STURGEON (ACIPENSER FULVESCENS) SPERMATOZOA

    EPA Science Inventory

    Computer-assisted motility analysis (CASA) was used to evaluate the effect of cryopreservation and theophylline treatment on sperm motility of lake sturgeon (Acipenser fulvescens).Motility was recorded at 0 and 5 min postactivation.The effect of cryopreservation on sperm acrosin-...

  6. Electronic archival tags provide first glimpse of bathythermal habitat use by free-ranging adult lake sturgeon Acipenser fulvescens

    USGS Publications Warehouse

    Briggs, Andrew S.; Hondorp, Darryl W.; Quinlan, Henry R.; Boase, James C.; Mohr, Lloyd C.

    2016-01-01

    Information on lake sturgeon (Acipenser fulvescens) depth and thermal habitat use during non-spawning periods is unavailable due to the difficulty of observing lake sturgeon away from shallow water spawning sites. In 2002 and 2003, lake sturgeon captured in commercial trap nets near Sarnia, Ontario were implanted with archival tags and released back into southern Lake Huron. Five of the 40 tagged individuals were recaptured and were at large for 32, 57, 286, 301, and 880 days. Temperatures and depths recorded by archival tags ranged from 0 to 23.5 ºC and 0.1 to 42.4 m, respectively. For the three lake sturgeon that were at large for over 200 days, temperatures occupied emulated seasonal fluctuations. Two of these fish occupied deeper waters during winter than summer while the other occupied similar depths during non-spawning periods. This study provides important insight into depth and thermal habitat use of lake sturgeon throughout the calendar year along with exploring the feasibility of using archival tags to obtain important physical habitat attributes during non-spawning periods.

  7. Accelerometer-derived activity correlates with volitional swimming speed in lake sturgeon (Acipenser fulvescens)

    USGS Publications Warehouse

    Thiem, J.D.; Dawson, J.W.; Gleiss, A.C.; Martins, E.G.; Haro, Alexander J.; Castro-Santos, Theodore R.; Danylchuk, A.J.; Wilson, R.P.; Cooke, S.J.

    2015-01-01

    Quantifying fine-scale locomotor behaviours associated with different activities is challenging for free-swimming fish.Biologging and biotelemetry tools can help address this problem. An open channel flume was used to generate volitionalswimming speed (Us) estimates of cultured lake sturgeon (Acipenser fulvescens Rafinesque, 1817) and these were paired withsimultaneously recorded accelerometer-derived metrics of activity obtained from three types of data-storage tags. This studyexamined whether a predictive relationship could be established between four different activity metrics (tail-beat frequency(TBF), tail-beat acceleration amplitude (TBAA), overall dynamic body acceleration (ODBA), and vectorial dynamic body acceleration(VeDBA)) and the swimming speed of A. fulvescens. Volitional Us of sturgeon ranged from 0.48 to 2.70 m·s−1 (0.51–3.18 bodylengths (BL) · s−1). Swimming speed increased linearly with all accelerometer-derived metrics, and when all tag types werecombined, Us increased 0.46 BL·s−1 for every 1 Hz increase in TBF, and 0.94, 0.61, and 0.94 BL·s−1 for every 1g increase in TBAA,ODBA, and VeDBA, respectively. Predictive relationships varied among tag types and tag-specific parameter estimates of Us arepresented for all metrics. This use of acceleration data-storage tags demonstrated their applicability for the field quantificationof sturgeon swimming speed.

  8. Identification and response to metals of metallothionein in two ancient fishes: white sturgeon (Acipenser transmontanus) and lake sturgeon (Acipenser fulvescens).

    PubMed

    Doering, Jon A; Beitel, Shawn C; Eisner, Bryanna K; Heide, Timon; Hollert, Henner; Giesy, John P; Hecker, Markus; Wiseman, Steve B

    2015-05-01

    White sturgeon (Acipenser transmontanus) are among the most sensitive species of fishes to Cu, Cd, and Zn, but there is no information about sensitivity of lake sturgeon (Acipenser fulvescens). To begin to elucidate molecular mechanism(s) of sensitivity of sturgeons to metals a cDNA encoding metallothionein (MT) was amplified from livers of white sturgeon (WS-MT) and lake sturgeon (LS-MT), and expression in response to Cu, Cd, or Zn was characterized in liver explants from each species. The primary structure of WS-MT and LS-MT contained 20 cysteine residues, which is the same as MTs of teleost fishes. However, the primary structure of WS-MT and LS-MT contained 63 amino acids, which is longer than any MT identified in teleost fishes. Abundance of transcripts of WS-MT in explants exposed to 0.3, 3, 30, or 100 μg/L of Cu was 1.7-, 1.7-, 2.1-, and 2.6-fold less than in controls, respectively. In contrast, abundances of transcripts of WS-MT were 3.3- and 2.4-fold greater in explants exposed to 30 μg/L of Cd and 1000 μg/L of Zn, respectively. Abundance of transcripts of LS-MT was not significantly different at any concentration of Cu, Cd, or Zn. MT is hypothesized to represent a critical mechanism for detoxification of metals. Therefore, results of this study suggest that sensitivity of sturgeons to exposure to Cu, Cd, or Zn might be a result of the relatively lesser maximal response of MT to metals. The study also suggestslake sturgeon might be more sensitive than white sturgeon to metals. PMID:25795035

  9. Microscopic identification of novel cell types in the integument of larval lake sturgeon, Acipenser fulvescens.

    PubMed

    Shute, Lauren; Huebner, Erwin; Anderson, W Gary

    2016-01-01

    Osmoregulation, respiration, nutrient/mineral transport, and defense mechanisms are all evident in the integument of fish. The role of the integument in these physiological processes is particularly important during early life history in larval fishes, as functional systems such as the gills and gastrointestinal tract are not fully developed. Using a variety of microscopy techniques, we describe the morphology of keratinocytes, mitochondria rich cells, ciliated cells and mucous cells of the skin, yolk sac, and gills. The cytology we observed was similar to previous studies describing the integument of larval fish, however, we have also identified two novel cell types on the integument of larval Lake Sturgeon, Acipenser fulvescens, between 9 and 34 days post fertilization. Our detailed analysis included a multifaceted microscopy approach using scanning electron, transmission electron, and light microscopy to elucidate the histology of the tissue and cellular morphology in addition to quantification and distribution of these novel cell types. The first cell type had a characteristic ampullary shape with a central cavity and a pore opening at the surface. The second, located on the free surface of the epidermis, had an uneven plasma membrane surface. Based on the abundance of secretory vesicles, organelles necessary for protein synthesis, and the lack of neural connection in both cell types, we propose these cells to be involved in the release of semiochemicals that may act as a pheromone, alarm substance, or chemical defense mechanism. PMID:26440535

  10. Microsatellite analyses across three diverse vertebrate transcriptomes (Acipenser fulvescens, Ambystoma tigrinum, and Dipodomys spectabilis).

    PubMed

    Doyle, Jacqueline M; Siegmund, Gregor; Ruhl, Joseph D; Eo, Soo Hyung; Hale, Matthew C; Marra, Nicholas J; Waser, Peter M; Dewoody, J Andrew

    2013-07-01

    Historically, many population genetics studies have utilized microsatellite markers sampled at random from the genome and presumed to be selectively neutral. Recent studies, however, have shown that microsatellites can occur in transcribed regions, where they are more likely to be under selection. In this study, we mined microsatellites from transcriptomes generated by 454-pyrosequencing for three vertebrate species: lake sturgeon (Acipenser fulvescens), tiger salamander (Ambystoma tigrinum), and kangaroo rat (Dipodomys spectabilis). We evaluated (i) the occurrence of microsatellites across species; (ii) whether particular gene ontology terms were over-represented in genes that contained microsatellites; (iii) whether repeat motifs were located in untranslated regions or coding sequences of genes; and (iv) in silico polymorphism. Microsatellites were less common in tiger salamanders than in either lake sturgeon or kangaroo rats. Across libraries, trinucleotides were found more frequently than any other motif type, presumably because they do not cause frameshift mutations. By evaluating variation across reads assembled to a given contig, we were able to identify repeat motifs likely to be polymorphic. Our study represents one of the first comparative data sets on the distribution of vertebrate microsatellites within expressed genes. Our results reinforce the idea that microsatellites do not always occur in noncoding DNA, but commonly occur in expressed genes. PMID:24099393

  11. Inheritance of microsatellite loci in the polyploid lake sturgeon (Acipenser fulvescens)

    USGS Publications Warehouse

    Pyatskowit, J.D.; Krueger, C.C.; Kincaid, H.L.; May, B.

    2001-01-01

    Inheritance in the expression of amplicons for four microsatellite primer pairs was determined using 10 families created from gametes of wild lake sturgeon (Acipenser fulvescens). Loci Afu34 and Afu68 expressed a maximum of two even-intensity bands per individual and had progeny genotype ratios that fit disomic inheritance (P > 0.05). Some variation exhibited at Afu34 and Afu68 was attributable to a null allele. Genotype expression at both loci also indicated that one female parent had transmitted unreduced gametes. Primer Afu39 amplified products that exhibited four gene doses, where genotype counts fit expected ratios for disomic inheritance (P > 0.05) indicating amplification of products from two disomic loci that share alleles. Meiotic drive was evident at the Afu39 loci based on a test for random segregation (P < 0.05). Only the expression of Afu19 gave evidence of tetrasomic inheritance based on a single progeny potentially produced by a double reduction gamete. No evidence for proposed octoploid inheritance was observed.

  12. Coding of sound direction in the auditory periphery of the lake sturgeon, Acipenser fulvescens

    PubMed Central

    Popper, Arthur N.; Fay, Richard R.

    2012-01-01

    The lake sturgeon, Acipenser fulvescens, belongs to one of the few extant nonteleost ray-finned fishes and diverged from the main vertebrate lineage about 250 million years ago. The aim of this study was to use this species to explore the peripheral neural coding strategies for sound direction and compare these results to modern bony fishes (teleosts). Extracellular recordings were made from afferent neurons innervating the saccule and lagena of the inner ear while the fish was stimulated using a shaker system. Afferents were highly directional and strongly phase locked to the stimulus. Directional response profiles resembled cosine functions, and directional preferences occurred at a wide range of stimulus intensities (spanning at least 60 dB re 1 nm displacement). Seventy-six percent of afferents were directionally selective for stimuli in the vertical plane near 90° (up down) and did not respond to horizontal stimulation. Sixty-two percent of afferents responsive to horizontal stimulation had their best axis in azimuths near 0° (front back). These findings suggest that in the lake sturgeon, in contrast to teleosts, the saccule and lagena may convey more limited information about the direction of a sound source, raising the possibility that this species uses a different mechanism for localizing sound. For azimuth, a mechanism could involve the utricle or perhaps the computation of arrival time differences. For elevation, behavioral strategies such as directing the head to maximize input to the area of best sensitivity may be used. Alternatively, the lake sturgeon may have a more limited ability for sound source localization compared with teleosts. PMID:22031776

  13. Frequency tuning and intensity coding of sound in the auditory periphery of the lake sturgeon, Acipenser fulvescens

    PubMed Central

    Meyer, Michaela; Fay, Richard R.; Popper, Arthur N.

    2010-01-01

    Acipenser fulvescens, the lake sturgeon, belongs to one of the few extant non-teleost ray-finned (bony) fishes. The sturgeons (family Acipenseridae) have a phylogenetic history that dates back about 250 million years. The study reported here is the first investigation of peripheral coding strategies for spectral analysis in the auditory system in a non-teleost bony fish. We used a shaker system to simulate the particle motion component of sound during electrophysiological recordings of isolated single units from the eighth nerve innervating the saccule and lagena. Background activity and response characteristics of saccular and lagenar afferents (such as thresholds, response–level functions and temporal firing) resembled the ones found in teleosts. The distribution of best frequencies also resembled data in teleosts (except for Carassius auratus, goldfish) tested with the same stimulation method. The saccule and lagena in A. fulvescens contain otoconia, in contrast to the solid otoliths found in teleosts, however, this difference in otolith structure did not appear to affect threshold, frequency tuning, intensity- or temporal responses of auditory afferents. In general, the physiological characteristics common to A. fulvescens, teleosts and land vertebrates reflect important functions of the auditory system that may have been conserved throughout the evolution of vertebrates. PMID:20400642

  14. The inner ear morphology and hearing abilities of the Paddlefish (Polyodon spathula) and the Lake Sturgeon (Acipenser fulvescens).

    PubMed

    Lovell, J M; Findlay, M M; Moate, R M; Nedwell, J R; Pegg, M A

    2005-11-01

    Concern regarding the spread of silver carp (Hypopthalmichthys molitrix) and bighead carp (Aristichthysc nobilis) through the Illinois River has prompted the development of an Acoustic Fish Deterrent (AFD) system. The application of this technology has resulted in a need to understand the auditory physiology of fish other than the target species, in order to minimise the effect of the AFD barrier on the ecology of indigenous fish populations. To this end, both the structures involved in sound reception and the hearing abilities of the paddlefish (Polyodon spathula) and the lake sturgeon (Acipenser fulvescens) are studied here using a combination of morphological and physiological approaches, revealing that both fish are responsive to sounds ranging in frequency from 100 to 500 Hz. The lowest hearing thresholds from both species were acquired from frequencies in a bandwidth of between 200 and 300 Hz, with higher thresholds at 100 and 500 Hz. The rationale for studying hearing in P. spathula and A. fulvescens in particular, is the value placed on them by both the commercial caviar producing industry and by the recreational fisheries sector. The hearing abilities of twelve P. spathula and twelve A. fulvescens were tested in sound fields dominated by either sound pressure or particle motion, with the results showing that acipenseriform fish are responsive to the motion of water particles in a sound field, rather than the sound pressure component. In this study, we measure the intensity of the sound field required to evoke threshold responses using a pressure sensitive hydrophone, as pressure dominated sound fields are the most audible acoustic condition for specialists like H. molitrix and A. nobilis (the target species). The results of the auditory examination clearly show that P. spathula and A. fulvescens are not sensitive to sound pressure, and will therefore have a significantly higher deterrent threshold than H. molitrix and A. nobilis in a pressure dominated

  15. Comparison of select hematology and serum chemistry analtyes between wild-caught and aquarium-housed lake sturgeon (Acipenser fulvescens)

    USGS Publications Warehouse

    DiVincenti, Louis, Jr.; Priest, Heather; Walker, Kyle J.; Wyatt, Jeffrey D.; Dittman, Dawn

    2013-01-01

    Hematology and serum chemistry analytes were compared between wild-caught and aquarium-housed lake sturgeon (Acipenser fulvescens) to potentially improve understanding of medical issues in lake sturgeon. Blood samples were taken from 30 lake sturgeon exhibited in 11 institutions in the United States and from 23 experimentally stocked lake sturgeon caught in gill nets in the lower Genesee River in Rochester, New York, USA. For hematology, only segmented neutrophil count was significantly different, with wild-caught fish having a higher number of circulating neutrophils. For clinical chemistry analytes, chloride, uric acid, calcium, phosphate, glucose, aspartate aminotransferase, triglycerides, and creatine kinase were significantly different between the two cohorts. These differences are likely not clinically significant and are attributable to handling stress, variability in environmental parameters, or differences in nutritional status. This is the first report of hematology and serum chemistry values in aquarium-housed lake sturgeon and provides useful reference intervals for clinicians.

  16. Effects of acoustic tag implantation on lake sturgeon Acipenser fulvescens: lack of evidence for changes in behavior

    USGS Publications Warehouse

    Hondorp, Darryl W.; Holbrook, Christopher; Krueger, Charles C.

    2015-01-01

    An assumption of studies using acoustic telemetry is that surgical implantation of acoustic transmitters or tags does not alter behavior of tagged individuals. Evaluating the validity of this assumption can be difficult for large fish, such as adult sturgeons, not amenable to controlled laboratory experimentation. The purpose of this study was to determine if and when this assumption was valid for adult lake sturgeon Acipenser fulvescens tagged with large (34 g) acoustic transmitters and released into the St. Clair River during 2011–2014. The hypothesis that activity and reach-scale distributions of tagged and untagged lake sturgeon did not differ was tested by comparing movement frequencies, movement rates (speed-over-ground), and location-specific detection probabilities between newly-tagged lake sturgeon and presumably fully-recovered conspecifics tagged and released in prior years.

  17. Habitat used by juvenile lake sturgeon (Acipenser fulvescens) in the North Channel of the St. Clair River (Michigan, USA)

    USGS Publications Warehouse

    Boase, James C.; Manny, Bruce A.; Donald, Katherine A.L.; Kennedy, Gregory W.; Diana, James S.; Thomas, Michael V.; Chiotti, Justin A.

    2014-01-01

    Lake sturgeon (Acipenser fulvescens) occupy the St. Clair River, part of a channel connecting lakes Huron and Erie in the Laurentian Great Lakes. In the North Channel of the St. Clair River, juvenile lake sturgeon (3–7 years old and 582–793 mm in length) were studied to determine movement patterns and habitat usage. Fourteen juveniles were implanted with ultrasonic transmitters and tracked June–August of 2004, 2005 and 2006. Telemetry data, Geographic Information System software, side-scan sonar, video images of the river bottom, scuba diving, and benthic substrate samples were used to determine the extent and composition of habitats they occupied. Juvenile lake sturgeon habitat selection was strongly related to water depth. No fish were found in 700 mm in length selected sand and gravel areas mixed with zebra mussels and areas dominated by zebra mussels, while fish < 700 mm used these habitat types in proportion to their availability.

  18. Comparison of select hematology and serum chemistry analtyes between wild-caught and aquarium-housed lake sturgeon (Acipenser fulvescens).

    PubMed

    DiVincenti, Louis; Priest, Heather; Walker, Kyle J; Wyatt, Jeffrey D; Dittman, Dawn

    2013-12-01

    Hematology and serum chemistry analytes were compared between wild-caught and aquarium-housed lake sturgeon (Acipenser fulvescens) to potentially improve understanding of medical issues in lake sturgeon. Blood samples were taken from 30 lake sturgeon exhibited in 11 institutions in the United States and from 23 experimentally stocked lake sturgeon caught in gill nets in the lower Genesee River in Rochester, New York, USA. For hematology, only segmented neutrophil count was significantly different, with wild-caught fish having a higher number of circulating neutrophils. For clinical chemistry analytes, chloride, uric acid, calcium, phosphate, glucose, aspartate aminotransferase, triglycerides, and creatine kinase were significantly different between the two cohorts. These differences are likely not clinically significant and are attributable to handling stress, variability in environmental parameters, or differences in nutritional status. This is the first report of hematology and serum chemistry values in aquarium-housed lake sturgeon and provides useful reference intervals for clinicians. PMID:24450055

  19. Interannual variation in effective number of breeders and estimation of effective population size in long-lived iteroparous lake sturgeon (Acipenser fulvescens).

    PubMed

    Duong, Thuy Yen; Scribner, Kim T; Forsythe, Patrick S; Crossman, James A; Baker, Edward A

    2013-03-01

    Quantifying interannual variation in effective adult breeding number (N(b)) and relationships between N(b), effective population size (N(e)), adult census size (N) and population demographic characteristics are important to predict genetic changes in populations of conservation concern. Such relationships are rarely available for long-lived iteroparous species like lake sturgeon (Acipenser fulvescens). We estimated annual N(b) and generational N(e) using genotypes from 12 microsatellite loci for lake sturgeon adults (n = 796) captured during ten spawning seasons and offspring (n = 3925) collected during larval dispersal in a closed population over 8 years. Inbreeding and variance N(b) estimated using mean and variance in individual reproductive success derived from genetically identified parentage and using linkage disequilibrium (LD) were similar within and among years (interannual range of N(b) across estimators: 41-205). Variance in reproductive success and unequal sex ratios reduced N(b) relative to N on average 36.8% and 16.3%, respectively. Interannual variation in N(b)/N ratios (0.27-0.86) resulted from stable N and low standardized variance in reproductive success due to high proportions of adults breeding and the species' polygamous mating system, despite a 40-fold difference in annual larval production across years (437-16 417). Results indicated environmental conditions and features of the species' reproductive ecology interact to affect demographic parameters and N(b)/N. Estimates of N(e) based on three single-sample estimators, including LD, approximate Bayesian computation and sibship assignment, were similar to annual estimates of N(b). Findings have important implications concerning applications of genetic monitoring in conservation planning for lake sturgeon and other species with similar life histories and mating systems. PMID:23293919

  20. Evidence of Circadian Rhythm, Oxygen Regulation Capacity, Metabolic Repeatability and Positive Correlations between Forced and Spontaneous Maximal Metabolic Rates in Lake Sturgeon Acipenser fulvescens

    PubMed Central

    Svendsen, Jon C.; Genz, Janet; Anderson, W. Gary; Stol, Jennifer A.; Watkinson, Douglas A.; Enders, Eva C.

    2014-01-01

    Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons). Using juvenile lake sturgeon (Acipenser fulvescens), the objective of this study was to test four hypotheses: 1) A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2) A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3) measurements of forced maximum metabolic rate (MMRF) are repeatable in individual fish; and 4) MMRF correlates positively with spontaneous maximum metabolic rate (MMRS). Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMRF. Trials lasting 24 h were used to measure standard metabolic rate (SMR) and MMRS. Repeatability and correlations between MMRF and MMRS were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O2sat)), demonstrating oxygen regulation. In contrast, MMRF was affected by hypoxia and decreased across the range from 100% O2sat to 70% O2sat. MMRF was repeatable in individual fish, and MMRF correlated positively with MMRS, but the relationships between MMRF and MMRS were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor). Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMRF and MMRS support the conjecture that MMRF represents a measure of organism performance that could be a target of natural selection. PMID:24718688

  1. Effects of Lampricide on Olfaction and Behavior in Young-of-the-Year Lake Sturgeon (Acipenser fulvescens).

    PubMed

    Sakamoto, Kathrine; Dew, William A; Hecnar, Stephen J; Pyle, Gregory G

    2016-04-01

    The lampricide, 3-trifluoromethyl-4-nitrophenol (TFM), is a primary component to sea lamprey control in the Laurentian Great Lakes. Though the lethal effects of TFM are well-known, the sublethal effects on fishes are virtually unknown. Here we studied the effects of TFM on the olfactory capabilities and behavior of young-of-the-year (YOY) lake sturgeon (Acipenser fulvescens). At ecologically relevant concentrations of TFM there was reduced olfactory response to all three cues (l-alanine, taurocholic acid, food cue) tested, suggesting that TFM inhibits both olfactory sensory neurons tested. Sturgeon exposed to TFM also showed a reduced attraction to the scent of food and reduced consumption of food relative to unexposed fish. Exposed fish were more active than control fish, but with slower acceleration. Fish were able to detect the scent of TFM, but failed to avoid it in behavioral trials. The connection between neurophysiological and behavioral changes, and the commonality of habitats between sturgeon and lamprey ammocoetes, suggests that there may be effects at the ecosystem level in streams that undergo lamprey control treatments. PMID:27015540

  2. A new species of nucleo-cytoplasmic large DNA virus (NCLDV) associated with mortalities in Manitoba lake sturgeon Acipenser fulvescens.

    PubMed

    Clouthier, Sharon C; Vanwalleghem, Elissa; Copeland, Shelagh; Klassen, Cheryl; Hobbs, Gary; Nielsen, Ole; Anderson, Eric D

    2013-02-28

    A newly discovered virus, Namao virus, associated with morbidity and mortality, was detected among juvenile lake sturgeon Acipenser fulvescens being propagated by a conservation stocking program for this endangered species in Manitoba, Canada. The outbreaks resulted in cumulative mortalities of 62 to 99.6% among progeny of wild Winnipeg River or Nelson River lake sturgeon and occurred at 2 geographically separate facilities. Namao virus was detected in almost 94% of the moribund or dead lake sturgeon according to a conventional polymerase chain reaction (cPCR) test that is based upon amplification of a 219 bp fragment of the virus major capsid protein (MCP). The virus itself was large (242 to 282 nm) and icosahedral-shaped with 2 capsids and a condensed bar-shaped core. It was found in virus factories within the host cell cytoplasm and displayed a tropism for the integument. Namao virus caused cellular changes characterized by enlarged eosinophilic epithelial cells in the gills and skin. Samples suspected of containing Namao virus did not have cytopathic effects on primary lake sturgeon or established white sturgeon cell lines. However, viral nucleic acid was detected in the former after prolonged incubation periods. Using primers designed from conserved regions of the MCP from NCLDVs, an estimated 95 to 96% of the Namao virus MCP open reading frame was captured. Phylogenetic analysis using the MCP of Namao virus and 27 other NCLDVs suggested that Namao virus and white sturgeon iridovirus share a common evolutionary past and might be members of the family Mimiviridae or a new, as yet unrecognized, virus family. PMID:23446969

  3. Evaluation of liver histopathology and EROD activity in St. Lawrence lake sturgeon (Acipenser fulvescens) in comparison with a reference population

    SciTech Connect

    Rousseaux, C.G. ||; Branchaud, A.; Spear, P.A.

    1995-05-01

    In an attempt to evaluate the effects of contaminants on the lake sturgeon Acipenser fulvescens, fish were netted from two sites: Riviere des Prairies, confluent with the St. Lawrence River near Montreal, and a reference site on the upper reaches of the Ottawa River in the La Verendrye Park. Livers of fish collected from the Riviere des Prairies were difficult to homogenize, and they left behind strands of what appeared to be connective tissue. Suspecting hepatic fibrosis, the authors decided to evaluate the livers for histopathologic changes. Nineteen adult lake sturgeon (eleven male and eight female) were examined. Following fixation, routine processing, sectioning, and staining with hematoxylin and eosin, microscopic evaluation revealed the following: Sections taken from livers of fish from the Riviere des Prairies site showed excessive fat accumulation and often severe chronic-active cholangiohepatitis. Bile duct proliferation (p < 0.0001), periportal fibrosis (p < 0.0001), inflammation (p < 0.001), and fat accumulation (p < 0.05) were more pronounced in the fish from the Riviere des Prairies site. Melano-macrophage centers appeared to be both paler and gave the appearance of fewer numbers (p < 0.01). Livers from lake sturgeon taken from the reference site had a more normal appearance. The EROD levels were also significantly induced in these fish (reference 3.39 {+-} 0.57; Riviere des Prairies site 8.21 {+-} 0.87 pmol/mg protein/min; p < 0.0005). The EROD levels positively correlated with bile duct proliferation (r{sup 2} = 0.44; p = 0.001) and periportal fibrosis (r{sup 2} = 0.41; p = 0.002). Despite the statistical associations above, the authors cannot categorically state that contaminants are the sole cause of the lesions seen.

  4. Next-generation pyrosequencing of gonad transcriptomes in the polyploid lake sturgeon (Acipenser fulvescens): the relative merits of normalization and rarefaction in gene discovery

    PubMed Central

    Hale, Matthew C; McCormick, Cory R; Jackson, James R; DeWoody, J Andrew

    2009-01-01

    Background Next-generation sequencing technologies have been applied most often to model organisms or species closely related to a model. However, these methods have the potential to be valuable in many wild organisms, including those of conservation concern. We used Roche 454 pyrosequencing to characterize gene expression in polyploid lake sturgeon (Acipenser fulvescens) gonads. Results Titration runs on a Roche 454 GS-FLX produced more than 47,000 sequencing reads. These reads represented 20,741 unique sequences that passed quality control (mean length = 186 bp). These were assembled into 1,831 contigs (mean contig depth = 4.1 sequences). Over 4,000 sequencing reads (~19%) were assigned gene ontologies, mostly to protein, RNA, and ion binding. A total of 877 candidate SNPs were identified from > 50 different genes. We employed an analytical approach from theoretical ecology (rarefaction) to evaluate depth of sequencing coverage relative to gene discovery. We also considered the relative merits of normalized versus native cDNA libraries when using next-generation sequencing platforms. Not surprisingly, fewer genes from the normalized libraries were rRNA subunits. Rarefaction suggests that normalization has little influence on the efficiency of gene discovery, at least when working with thousands of reads from a single tissue type. Conclusion Our data indicate that titration runs on 454 sequencers can characterize thousands of expressed sequence tags which can be used to identify SNPs, gene ontologies, and levels of gene expression in species of conservation concern. We anticipate that rarefaction will be useful in evaluations of gene discovery and that next-generation sequencing technologies hold great potential for the study of other non-model organisms. PMID:19402907

  5. Length-weight relationship and a relative condition factor equation for lake sturgeon (Acipenser fulvescens) from the St Clair River system (Michigan, USA)

    USGS Publications Warehouse

    Craig, J.M.; Thomas, M.V.; Nichols, S.J.

    2005-01-01

    Several USA state, federal, and Canadian agencies study lake sturgeon (Acipenser fulvescens) within the St Clair River and Lake St Clair, collectively referred to hereafter as the St Clair River (SCR) system. Previously, there has been no set standard for determining condition for SCR system lake sturgeon. Condition measures the variation from the expected weight for length as an indicator of fatness, general well-being, gonad development, etc. The aim of this project was to determine the length weight relationship of lake sturgeon caught from the SCR system, from which a relative condition factor (Kn) equation could be derived. Total length (TL, mm) and weight (W, kg) were measured for 1074 lake sturgeon (101 males and 16 females were identifiable) collected by setline and bottom trawl from the SCR system in May-September, 1997-2002. Analysis of covariance found no difference in the length-weight relationship between sampling gear or sex. Least-squares regression of log10W ?? log10TL produced the overall equation logW = 3.365logTL - 9.320. Using the exponential form of the slope and y-intercept, relative condition factor for lake sturgeon from the SCR system can be calculated as Kn - W/[(4.786 ?? 10-10)(TL3.365)]. Equations for males and females were also developed. Overall, body condition was significantly correlated with both age and girth; no significant difference in Kn by sex was found. In general, the SCR lake sturgeon population was near the upper ends of growth and condition ranges listed in the literature, comparable with those populations that are at similar latitudes. Although condition factors should be interpreted with caution, proper use of a standard equation provides a non-lethal measure of overall fish health that can be used by biologists and managers in ongoing efforts to restore lake sturgeon throughout the Great Lakes. ?? 2005 Blackwell Verlag, Berlin.

  6. Length-weight relationship and a relative condition factor equation for lake sturgeon (Acipenser fulvescens) from the St. Clair River system (Michigan, USA)

    USGS Publications Warehouse

    Craig, Jaquelyn M.; Thomas, Michael V.; Nichols, S. Jerrine

    2005-01-01

    Several USA state, federal, and Canadian agencies study lake sturgeon (Acipenser fulvescens) within the St Clair River and Lake St Clair, collectively referred to hereafter as the St Clair River (SCR) system. Previously, there has been no set standard for determining condition for SCR system lake sturgeon. Condition measures the variation from the expected weight for length as an indicator of fatness, general well-being, gonad development, etc. The aim of this project was to determine the length-weight relationship of lake sturgeon caught from the SCR system, from which a relative condition factor (Kn) equation could be derived. Total length (TL, mm) and weight (W, kg) were measured for 1074 lake sturgeon (101 males and 16 females were identifiable) collected by setline and bottom trawl from the SCR system in May-September, 1997-2002. Analysis of covariance found no difference in the length-weight relationship between sampling gear or sex. Least-squares regression of log10W x log10TL produced the overall equation logW = 3.365logTL - 9.320. Using the exponential form of the slope and y-intercept, relative condition factor for lake sturgeon from the SCR system can be calculated as Kn = W/ [(4.786 x 10-10)(TL3.365)]. Equations for males and females were also developed. Overall, body condition was significantly correlated with both age and girth; no significant difference in Kn by sex was found. In general, the SCR lake sturgeon population was near the upper ends of growth and condition ranges listed in the literature, comparable with those populations that are at similar latitudes. Although condition factors should be interpreted with caution, proper use of a standard equation provides a non-lethal measure of overall fish health that can be used by biologists and managers in ongoing efforts to restore lake sturgeon throughout the Great Lakes.

  7. Length-weight relationship and a relative condition factor equation for lake sturgeon (Acipenser fulvescens) from the St. Clair River system (Michigan, USA)

    USGS Publications Warehouse

    Craig, Jaquelyn; Thomas, Michael V.; Nichols, Susan Jerrine

    2005-01-01

    Several USA state, federal, and Canadian agencies study lake sturgeon (Acipenser fulvescens) within the St Clair River and Lake St Clair, collectively referred to hereafter as the St Clair River (SCR) system. Previously, there has been no set standard for determining condition for SCR system lake sturgeon. Condition measures the variation from the expected weight for length as an indicator of fatness, general well-being, gonad development, etc. The aim of this project was to determine the length–weight relationship of lake sturgeon caught from the SCR system, from which a relative condition factor (Kn) equation could be derived. Total length (TL, mm) and weight (W, kg) were measured for 1074 lake sturgeon (101 males and 16 females were identifiable) collected by setline and bottom trawl from the SCR system in May–September, 1997–2002. Analysis of covariance found no difference in the length–weight relationship between sampling gear or sex. Least-squares regression of log10W × log10TL produced the overall equation logW = 3.365logTL − 9.320. Using the exponential form of the slope and y-intercept, relative condition factor for lake sturgeon from the SCR system can be calculated as Kn = W/[(4.786 × 10−10)(TL3.365)]. Equations for males and females were also developed. Overall, body condition was significantly correlated with both age and girth; no significant difference in Kn by sex was found. In general, the SCR lake sturgeon population was near the upper ends of growth and condition ranges listed in the literature, comparable with those populations that are at similar latitudes. Although condition factors should be interpreted with caution, proper use of a standard equation provides a non-lethal measure of overall fish health that can be used by biologists and managers in ongoing efforts to restore lake sturgeon throughout the Great Lakes.

  8. Using drift nets to capture early life stages and monitor spawning of the yangtze river chinese sturgeon (Acipenser sinensis)

    USGS Publications Warehouse

    Wei, Q.W.; Kynard, B.; Yang, D.G.; Chen, X.H.; Du, H.; Shen, L.; Zhang, H.

    2009-01-01

    A sampling system for capturing sturgeon eggs using a D-shaped bottom anchored drift net was used to capture early life stages (ELS) of Chinese sturgeon, Acipenser sinensis, and monitor annual spawning success at Yichang on the Yangtze River, 1996-2004, before and just after the Three Gorges Dam began operation. Captured were 96 875 ELS (early life stages: eggs, yolk-sac larvae = eleuthero embryos, and larvae); most were eggs and only 2477 were yolk-sac larvae. Most ELS were captured in the main river channel and inside the bend at the Yichang spawning reach. Yolk-sac larvae were captured for a maximum of 3 days after hatching began, indicating quick dispersal downstream. The back-calculated day of egg fertilization over the eight years indicated a maximum spawning window of 23 days (20 October-10 November). Spawning in all years was restricted temporally, occurred mostly at night and during one or two spawning periods, each lasting several days. The brief temporal spawning window may reduce egg predation by opportunistic predators by flooding the river bottom with millions of eggs. During 1996-2002, the percentage of fertilized eggs in an annual 20-egg sample was between 63.5 to 94.1%; however, in 2003 the percentage fertilized was only 23.8%. This sudden decline may be related to the altered environmental conditions at Yichang caused by operation of the Three Gorges Dam. Further studies are needed to monitor spawning and changes in egg fertilization in this threatened population. ?? 2009 Blackwell Verlag GmbH.

  9. Acute toxicity of TFM and a TFM/niclosamide mixture to selected species of fish, including lake sturgeon (Acipenser fulvescens) and mudpuppies (Necturus maculosus), in laboratory and field exposures

    USGS Publications Warehouse

    Boogaard, M.A.; Bills, T.D.; Johnson, D.A.

    2003-01-01

    The toxicity of the lampricides 3-trifluoromethyl-4-nitrophenol (TFM) and 2',5-dichloro-4'-nitrosalicylanilide (niclosamide) to non-target fishes has been a major point of concern since their use to control larval sea lamprey (Petromyzon marinus) populations began in the early 1960s. The toxicity of TFM to several non-target fish species has been demonstrated in previous studies. However, little information is available on the toxicity of the TFM/1% niclosamide mixture. One species of particular concern is the lake sturgeon (Acipenser fulvescens). Juvenile lake sturgeon of several size ranges were exposed to determine potential effects of the lampricides to individuals present in treatment streams. Sac fry were most resistant to the lampricides followed by fingerlings in the 200 to 225 mm size range. Swim-up fry and fingerlings less than 100 mm were the most sensitive. Concentrations that produced 50% mortality (LC50s) in juvenile lake sturgeon of these smaller size ranges were at or near the minimum lethal concentrations (MLCs) required for effective control of larval sea lampreys. The mudpuppy (Necturus maculosus), an amphibian native to several tributaries of the Great Lakes, have also become a species of interest in recent years. Laboratory tests conducted with TFM and a TFM/1% niclosamide mixture on adult mudpuppies indicate that although the amphibian is sensitive to the lampricides, an adequate margin of safety exists for adult mudpuppies to survive when exposed during stream treatments. Fifteen other fish species native to streams treated with lampricides were investigated in the laboratory to determine their sensitivity to the lampricides. Centrarchids, bluegill (Lepomis macrochirus) and green sunfish (Lepomis cyanellus) were the least sensitive to TFM, while ictalurids, black bullhead (Ictalurus melas), channel catfish (Ictalurus punctatus), and tadpole madtom (Notorus gyrinus) were the most sensitive. On-site bioassays conducted before lampricide

  10. Acute toxicity of TFM and a TFM/niclosamide mixture to selected species of fish, including lake sturgeon (Acipenser fulvescens) and mudpuppies (Necturus maculosus), in laboratory and field exposures

    USGS Publications Warehouse

    Boogaard, M.A.; Bills, T.D.; Johnson, D.A.

    2003-01-01

    The toxicity of the lampricides 3-trifluoromethyl-4-nitrophenol (TFM) and 2???,5-dichloro-4???-nitrosalicylanilide (niclosamide) to non-target fishes has been a major point of concern since their use to control larval sea lamprey (Petromyzon marinus) populations began in the early 1960s. The toxicity of TFM to several non-target fish species has been demonstrated in previous studies. However, little information is available on the toxicity of the TFM/1 % niclosamide mixture. One species of particular concern is the lake sturgeon (Acipenser fulvescens). Juvenile lake sturgeon of several size ranges were exposed to determine potential effects of the lampricides to individuals present in treatment streams. Sac fry were most resistant to the lampricides followed by fingerlings in the 200 to 225 mm size range. Swim-up fry and fingerlings less than 100 mm were the most sensitive. Concentrations that produced 50% mortality (LC50s) in juvenile lake sturgeon of these smaller size ranges were at or near the minimum lethal concentrations (MLCs) required for effective control of larval sea lampreys. The mudpuppy (Necturus maculosus), an amphibian native to several tributaries of the Great Lakes, have also become a species of interest in recent years. Laboratory tests conducted with TFM and a TFM/1 % niclosamide mixture on adult mudpuppies indicate that although the amphibian is sensitive to the lampricides, an adequate margin of safety exists for adult mudpuppies to survive when exposed during stream treatments. Fifteen other fish species native to streams treated with lampricides were investigated in the laboratory to determine their sensitivity to the lampricides. Centrarchids, bluegill (Lepomis macrochirus) and green sunfish (Lepomis cyanellus) were the least sensitive to TFM, while ictalurids, black bullhead (Ictalurus melas), channel catfish (Ictalurus punctatus), and tadpole madtom (Notorus gyrinus) were the most sensitive. On-site bioassays conducted before lampricide

  11. A model to locate potential areas for lake sturgeon spawning habitat construction in the St. Clair–Detroit River System

    USGS Publications Warehouse

    Bennion, David; Manny, Bruce A.

    2014-01-01

    In response to a need for objective scientific information that could be used to help remediate loss of fish spawning habitat in the St. Clair River and Detroit River International Areas of Concern, this paper summarizes a large-scale geographic mapping investigation. Our study integrates data on two variables that many riverine fishes respond to in selecting where to spawn in these waters (water flow velocity and water depth) with available maps of the St. Clair–Detroit River System (SC–DRS). Our objectives were to locate and map these two physical components of fish habitat in the St. Clair and Detroit rivers and Lake St. Clair using a geographic information system (GIS) and to identify where, theoretically, fish spawning habitat could be remediated in these rivers. The target fish species to which this model applies is lake sturgeon (Acipenser fulvescens), but spawning reefs constructed for lake sturgeon in this system have been used for spawning by 17 species of fish. Our analysis revealed areas in each river that possessed suitable water velocity and depth for fish spawning and therefore could theoretically be remediated by the addition of rock-rubble substrate like that used at two previously remediated sites in the Detroit River at Belle Isle and Fighting Island. Results of our analysis revealed that only 3% of the total area of the SC–DRS possesses the necessary combination of water depth and high flow velocity to be indicated by the model as potential spawning habitat for lake sturgeon.

  12. Response of spawning lake sturgeons to change in hydroelectric facility operation

    SciTech Connect

    Auer, N.A.

    1996-01-01

    Spawning of lake sturgeon Acipenser fulvescens was documented from 1987 to 1992 below the Prickett hydroelectric facility on the Sturgeon River, a tributary to Portage Lake, Michigan. Lake sturgeons were captured at the spawning site with dip nets during periods of reduced flow. A change in the spawning characteristics of the population was noted that corresponded to a changed in the operation of the hydroelectric facility. In 1987 and 1988 the facility operated in a peaking mode, which resulted in large daily fluctuations in river flows. The years 1989 and 1990 were years of transition, and in 1991 and 1992 the facility released near run-of-the-river (ROR) flows. Under near-ROR flows, which were more natural, adult lake sturgeons spent 4-6 weeks less at the spawning sites, 74% more fish were observed, weights were greater due to a 68% increase in number of females, and fish had increased reproductive readiness. The change in flow regime was the result of a Federal Energy Regulatory Commission relicensing action. The positive response observed in lake sturgeon spawning activity that resulted from the change of facility operation to near-ROR flows should be beneficial to the survival and perpetuation of this population. Similar results may be experienced in other lake sturgeon waters affected by manipulated flow regimes. 28 refs., 5 figs., 6 tabs.

  13. Adaption of egg and larvae sampling techniques for lake sturgeon and broadcast spawning fishes in a deep river

    USGS Publications Warehouse

    Roseman, Edward F.; Kennedy, Gregory W.; Craig, Jaquelyn; Boase, James; Soper, Karen

    2011-01-01

    In this report we describe how we adapted two techniques for sampling lake sturgeon (Acipenser fulvescens) and other fish early life history stages to meet our research needs in the Detroit River, a deep, flowing Great Lakes connecting channel. First, we developed a buoy-less method for sampling fish eggs and spawning activity using egg mats deployed on the river bottom. The buoy-less method allowed us to fish gear in areas frequented by boaters and recreational anglers, thus eliminating surface obstructions that interfered with recreational and boating activities. The buoy-less method also reduced gear loss due to drift when masses of floating aquatic vegetation would accumulate on buoys and lines, increasing the drag on the gear and pulling it downstream. Second, we adapted a D-frame drift net system formerly employed in shallow streams to assess larval lake sturgeon dispersal for use in the deeper (>8 m) Detroit River using an anchor and buoy system.

  14. Adaption of egg and larvae sampling techniques for lake sturgeon and broadcast spawning fishes in a deep river

    USGS Publications Warehouse

    Roseman, E.F.; Boase, J.; Kennedy, G.; Craig, J.; Soper, K.

    2011-01-01

    In this report we describe how we adapted two techniques for sampling lake sturgeon (Acipenser fulvescens) and other fish early life history stages to meet our research needs in the Detroit River, a deep, flowing Great Lakes connecting channel. First, we developed a buoy-less method for sampling fish eggs and spawning activity using egg mats deployed on the river bottom. The buoy-less method allowed us to fish gear in areas frequented by boaters and recreational anglers, thus eliminating surface obstructions that interfered with recreational and boating activities. The buoy-less method also reduced gear loss due to drift when masses of floating aquatic vegetation would accumulate on buoys and lines, increasing the drag on the gear and pulling it downstream. Second, we adapted a D-frame drift net system formerly employed in shallow streams to assess larval lake sturgeon dispersal for use in the deeper (>8m) Detroit River using an anchor and buoy system. ?? 2011 Blackwell Verlag, Berlin.

  15. Lake sturgeon response to a spawning reef constructed in the Detroit river

    USGS Publications Warehouse

    Roseman, Edward F.; Manny, B.; Boase, J.; Child, M.; Kennedy, G.; Craig, J.; Soper, K.; Drouin, R.

    2011-01-01

    Prior to the First World War, the bi-national Detroit River provided vast areas of functional fish spawning and nursery habitat. However, ongoing conflicting human uses of these waters for activities such as waste disposal, water withdrawals, shoreline development, shipping, recreation, and fishing have altered many of the chemical, physical, and biological processes of the Detroit River. Of particular interest and concern to resource managers and stakeholders is the significant loss and impairment of fish spawning and nursery habitat that led to the decline in abundance of most fish species using this ecosystem. Lake sturgeon (Acipenser fulvescens) populations for example, were nearly extirpated by the middle of the 20th century, leaving only a small fraction of their former population. Fisheries managers recognized that the loss of suitable fish spawning habitat is a limiting factor in lake sturgeon population rehabilitation in the Detroit River. In efforts to remediate this beneficial water use impairment, a reef consisting of a mixture of natural rock and limestone was constructed at the upstream end of Fighting Island in 2008. This paper focuses on the response by lake sturgeon to the different replicates of suitable natural materials used to construct the fish spawning habitat at Fighting Island in the Detroit River. Pre-construction fisheries assessment during 2006–2008 showed that along with the presence of adult lake sturgeon, spawning conditions were favorable. However, no eggs were found in assessments conducted prior to reef construction. The 3300 m2 Fighting Island reef was placed at the upstream end of the island in October of 2008. The construction design included 12 spawning beds of three replicates each consisting of either round rock, small or large (shot-rock) diameter limestone or a mixture thereof. An observed response by spawning lake sturgeon occurred the following year when spawning-ready adults (ripe), viable eggs, and larvae were

  16. Atlantic sturgeons (Acipenser sturio, Acipenser oxyrinchus): American females successful in Europe

    NASA Astrophysics Data System (ADS)

    Tiedemann, Ralph; Moll, Katja; Paulus, Kirsten B.; Scheer, Michael; Williot, Patrick; Bartel, Ryszard; Gessner, Jörn; Kirschbaum, Frank

    2007-03-01

    Recent molecular data on the maternally inherited mitochondrial (mt) DNA have challenged the traditional view that the now extinct Baltic sturgeon population belonged to the European sturgeon Acipenser sturio. Instead, there is evidence that American sea sturgeon Acipenser oxyrinchus historically immigrated into the Baltic Sea. In this study, we test the hypothesis that A. oxyrinchus introgressed into, rather than replaced, the A. sturio population in the Baltic. We established four single nucleotide polymorphisms (SNPs) in the nuclear MHC II antigen gene with a species-specific SNP pattern. Using an ancient DNA approach and two independent lines of molecular evidence (sequencing of allele-specific clones, SNaPshot), we detected both A. sturio and A. oxyrinchus alleles in the available museum material of the now extinct Baltic sturgeon population. The hybrid nature of the Baltic population was further confirmed by very high levels of heterozygosity. It had been previously postulated that the immigration of the cold-adapted A. oxyrinchus into the Baltic occurred during the Medieval Little Ice Age, when temperature likely dropped below the degree inducing spawning in A. sturio. Under this scenario, our new findings suggest that the genetic mosaic pattern in the Baltic sturgeon population (oxyrinchus mtDNA, sturio and oxyrinchus MHC alleles) is possibly caused by sex-biased introgression where spawning was largely restricted to immigrating American females, while fertilization was predominantly achieved by abundant local European males. The hybrid nature of the former Baltic sturgeon population should be taken into account in the current reintroduction measures.

  17. Dual annual spawning races in Atlantic sturgeon.

    PubMed

    Balazik, Matthew T; Musick, John A

    2015-01-01

    Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus, Acipenseridae) populations in the United States were listed as either endangered or threatened under the Endangered Species Act in 2012. Because of the endangered/threatened status, a better understanding of Atlantic sturgeon life-history behavior and habitat use is important for effective management. It has been widely documented that Atlantic sturgeon reproduction occurs from late winter to early summer, varying clinally with latitude. However, recent data show Atlantic sturgeon also spawn later in the year. The group that spawns later in the year seems to be completely separate from the spring spawning run. Recognition of the later spawning season has drastically modified estimates of the population status of Atlantic sturgeon in Virginia. With the combination of new telemetry data and historical documentation we describe a dual spawning strategy that likely occurs in various degrees along most, if not all, of the Atlantic sturgeon's range. Using new data combined with historical sources, a new spawning strategy emerges which managers and researchers should note when determining the status of Atlantic sturgeon populations and implementing conservation measures. PMID:26020631

  18. Dual Annual Spawning Races in Atlantic Sturgeon

    PubMed Central

    Balazik, Matthew T.; Musick, John A.

    2015-01-01

    Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus, Acipenseridae) populations in the United States were listed as either endangered or threatened under the Endangered Species Act in 2012. Because of the endangered/threatened status, a better understanding of Atlantic sturgeon life-history behavior and habitat use is important for effective management. It has been widely documented that Atlantic sturgeon reproduction occurs from late winter to early summer, varying clinally with latitude. However, recent data show Atlantic sturgeon also spawn later in the year. The group that spawns later in the year seems to be completely separate from the spring spawning run. Recognition of the later spawning season has drastically modified estimates of the population status of Atlantic sturgeon in Virginia. With the combination of new telemetry data and historical documentation we describe a dual spawning strategy that likely occurs in various degrees along most, if not all, of the Atlantic sturgeon's range. Using new data combined with historical sources, a new spawning strategy emerges which managers and researchers should note when determining the status of Atlantic sturgeon populations and implementing conservation measures. PMID:26020631

  19. White sturgeon spawning areas in the lower Snake River

    USGS Publications Warehouse

    Parsley, M.J.; Kappenman, K.M.

    2000-01-01

    We documented 17 white sturgeon Acipenser transmontanus spawning locations in the Snake River from the mouth to Lower Granite Dam (river km 0 to 173). Spawning locations were determined by the collection of fertilized eggs on artificial substrates or in plankton nets. We collected 245 eggs at seven locations in McNary Reservoir, 22 eggs at three locations in Ice Harbor Reservoir, 30 eggs from two locations in Lower Monumental Reservoir, and 464 eggs at five locations in Little Goose Reservoir. All 17 locations were in high water velocity areas and between 1.0 and 7.0 km downstream from a hydroelectric dam. The documentation of spawning areas is important because this habitat is necessary to maintain natural and viable populations.

  20. Population status of North American green sturgeon, Acipenser medirostris

    USGS Publications Warehouse

    Adams, P.B.; Grimes, C.; Hightower, J.E.; Lindley, S.T.; Moser, M.L.; Parsley, M.J.

    2007-01-01

    North American green sturgeon, Acipenser medirostris, was petitioned for listing under the Endangered Species Act (ESA). The two questions that need to be answered when considering an ESA listing are; (1) Is the entity a species under the ESA and if so (2) is the "species" in danger of extinction or likely to become an endangered species in the foreseeable future throughout all or a significant portion of its range? Green sturgeon genetic analyses showed strong differentiation between northern and southern populations, and therefore, the species was divided into Northern and Southern Distinct Population Segments (DPSs). The Northern DPS includes populations in the Rogue, Klamath-Trinity, and Eel rivers, while the Southern DPS only includes a single population in the Sacramento River. The principal risk factors for green sturgeon include loss of spawning habitat, harvest, and entrainment. The Northern DPS is not considered to be in danger of extinction or likely to become an endangered species in the foreseeable future. The loss of spawning habitat is not large enough to threaten this DPS, although the Eel River has been severely impacted by sedimentation due to poor land use practices and floods. The two main spawning populations in the Rogue and Klamath-Trinity rivers occupy separate basins reducing the potential for loss of the DPS through catastrophic events. Harvest has been substantially reduced and green sturgeon in this DPS do not face substantial entrainment loss. However there are significant concerns due to lack of information, flow and temperature issues, and habitat degradation. The Southern DPS is considered likely to become an endangered species in the foreseeable future. Green sturgeon in this DPS are concentrated into one spawning area outside of their natural habitat in the Sacramento River, making them vulnerable to catastrophic extinction. Green sturgeon spawning areas have been lost from the area above Shasta Dam on the Sacramento River and

  1. Overview of biology and aquaculture of Amur sturgeon (Acipenser schrenckii) in China

    USGS Publications Warehouse

    Zhuang, P.; Kynard, B.; Zhang, L.; Zhang, T.; Zhang, Z.; Li, D.

    2002-01-01

    Amur sturgeon, Acipenser schrenckii is a large riverine species (max. 3 m length and 190 kg weight) native to the Amur River. In the middle Amur River, males first spawn at 7-8 years of age and females at 9-10 years. Due to overfishing and habitat alteration, the abundance of wild stocks has rapidly declined in recent years. Using wild adults, artificial spawning began in the 1950s in China, and since the early 1990s Amur sturgeon has become the most popular sturgeon for aquaculture. The species is adaptive to many conditions of artificial culture, including traditional Chinese fish culture ponds, lakes, reservoirs, and cages. It will grow well on many types of food, and 1-year-old fish reared on commercial diets weigh 900-1200 g. Based on the examination of females reared for broodstock, first full sexual maturity is expected at 5-6 years of age.

  2. Life history and status of shortnose sturgeon (Acipenser brevirostrum) in the potomac river

    USGS Publications Warehouse

    Kynard, B.; Breece, M.; Atcheson, M.; Kieffer, M.; Mangold, M.

    2009-01-01

    We collected the first life history information on shortnose sturgeon (Acipenser brevirostrum) in any of the rivers to Chesapeake Bay, the geographic center of the species range. In the Potomac River, two telemetry-tagged adult females used 124 km of river: A saltwater/freshwater reach at river km (rkm) 63-141 was the foraging-wintering concentration area, and one female migrated to spawn at rkm 187 in Washington, DC. The spawning migration explained the life history context of an adult captured 122 years ago in Washington, DC, supporting the idea that a natal population once lived in the river. Repeated homing migrations to foraging and wintering areas suggested the adults were residents, not transient coastal migrants. All habitats that adults need to complete life history are present in the river. The Potomac River shortnose sturgeon offers a rare opportunity to learn about the natural rebuilding of a sturgeon population. ?? 2009 Blackwell Verlag, Berlin.

  3. Life history and status of shortnose sturgeon (Acipenser brevirostrum) in the Potomac River

    USGS Publications Warehouse

    Kieffer, Micah

    2009-01-01

    We collected the first life history information on shortnose sturgeon (Acipenser brevirostrum) in any of the rivers to Chesapeake Bay, the geographic center of the species range. In the Potomac River, two telemetry-tagged adult females used 124 km of river: a saltwater/freshwater reach at river km (rkm) 63-141 was the foraging-wintering concentration area, and one female migrated to spawn at rkm 187 in Washington, DC. The spawning migration explained the life history context of an adult captured 122 years ago in Washington, DC, supporting the idea that a natal population once lived in the river. Repeated homing migrations to foraging and wintering areas suggested the adults were residents, not transient coastal migrants. All habitats that adults need to complete life history are present in the river. The Potomac River shortnose sturgeon offers a rare opportunity to learn about the natural rebuilding of a sturgeon population.

  4. Fall spawning of Atlantic sturgeon in the Roanoke River, North Carolina

    USGS Publications Warehouse

    Smith, Joseph A.; Hightower, Joseph E.; Flowers, H. Jared

    2015-01-01

    In 2012, the National Oceanic and Atmospheric Administration (NOAA) declared Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus to be threatened or endangered throughout its range in U.S. waters. Restoration of the subspecies will require much new information, particularly on the location and timing of spawning. We used a combination of acoustic telemetry and sampling with anchored artificial substrates (spawning pads) to detect fall (September–November) spawning in the Roanoke River in North Carolina. This population is included in the Carolina Distinct Population Segment, which was classified by NOAA as endangered. Sampling was done immediately below the first shoals encountered by anadromous fishes, near Weldon. Our collection of 38 eggs during the 21 d that spawning pads were deployed appears to be the first such collection (spring or fall) for wild-spawned Atlantic Sturgeon eggs. Based on egg development stages, estimated spawning dates were September 17–18 and 18–19 at water temperatures from 25.3°C to 24.3°C and river discharge from 55 to 297 m3/s. These observations about fall spawning and habitat use should aid in protecting critical habitats and planning research on Atlantic Sturgeon spawning in other rivers.

  5. Using a semi-natural stream to produce young sturgeons for conservation stocking: Maintaining natural selection during spawning and rearing

    USGS Publications Warehouse

    Kynard, B.; Pugh, D.; Parker, T.; Kieffer, M.

    2011-01-01

    Young sturgeons used for conservation stocking are presently produced using the same methods used for commercial culture. To determine if young sturgeons could be produced without relaxing natural selection factors, we developed a semi-natural stream where we annually studied mating of wild shortnose sturgeon (Acipenser brevirostrum) observed movement of gametes released freely during spawning, and estimated the number of larvae produced by various densities of spawned eggs. The stream had a bottom area of 18.8m2, a rubble-gravel bottom, and a mean bottom current at 0.6 depth during spawning of 48cms-1 (range, 17-126cms-1). Wild adults successfully spawned in the stream each year for 7years (2002-2008). Some females and males were more successful during spawning than others, suggesting an unequal fitness during spawning among wild individuals, which is different than the controlled spawning fitness of individuals in hatcheries. Male and female gametes spawned naturally must connect quickly in the fast current or fail, a selection factor absent in hatcheries. The number of larvae produced was inversely related to spawned egg densitym-2 (R2=0.65) and the maximum number of larvae produced was 8000-16000 (425-851larvaem-2 of bottom). Artificial spawning streams have the potential to contribute to sturgeon restoration. ?? 2011 Blackwell Verlag, Berlin.

  6. Sequencing and analysis of complete mitochondrial genome of Niviventer fulvescens (Muridae).

    PubMed

    Yong, Bin; Wei, Haixue; Jia, Qiang; Chen, Shunde

    2016-09-01

    The complete mitochondrial genome was sequenced and annotated newly from an individual of Niviventer fulvescens (Muridae) from Sichuan province. The total length of the N. fulvescens mitogenome is 16 296 bp and contains 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a control region, with a base composition of 34.3%A, 29.1%T, 24.2%C and 12.4%G. The nucleotide sequence data of 12 heavy-strand protein-coding genes of N. fulvescens and other 18 rodents were used for mitochondrial genome phylogenetic analyses. Bayesian phylogenetic tree demonstrated the genus Niviventer was embedded within the genus Leopoldamys, although three Niviventer species constituted a monophyletic group. More complete mitochondrial genome sequences are required to illuminate the molecular phylogenetic relationship between Niviventer and Leopoldamys. PMID:26329164

  7. Population Origin of Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus Bycaught in U.S. Atlantic Coast Fisheries

    PubMed Central

    Wirgin, I.; Maceda, L.; Grunwald, C.; King, T.L.

    2015-01-01

    Microsatellite DNA and mitochondrial DNA control region sequence analyses were used to determine the population and Distinct Population Segment (DPS) origin of 173 Atlantic sturgeon Acipenser oxyrinchus oxyrinchus encountered from the Gulf of Maine to Cape Hatteras, North Carolina in NOAA's Northeast Fisheries Observer Program. It was found that the Hudson River was by far the greatest contributor to this coastal bycatch, with 42.2-46.3% of specimens originating there. Generally, specimens respected the geographic province of the river in which they were spawned, but some specimens, particularly those originating in the South Atlantic DPS, moved great distances. Genetic mixed stock analyses provides an accurate approach to determine the DPS and population origin of Atlantic sturgeon bycaught in coastal waters but most informative management requires that these results be partitioned by locale, season, target fishery, and gear type. PMID:25727098

  8. First report of Oxyspirura sp. from a captive fulvous owl (Strix fulvescens) in Mexico.

    PubMed

    Rodriguez-Tovar, L E; Casas-Martínez, A; Ramírez-Romero, R; Nevárez-Garza, A M; Zarate-Ramos, J J

    2008-12-01

    Nematodes similar to Oxyspirura sp. were recovered from the cornea and nictitating membrane of a fulvous owl (Strix fulvescens). The bird had been captive for several months, but died suddenly. It had no clinical history of prior diseases, including ocular lesions. PMID:18576870

  9. SpawnNet

    2014-12-23

    SpawnNet provides a networking interface similar to Linux sockets that runs natively on High-performance network interfaces. It is intended to be used to bootstrap parallel jobs and communication libraries like MPI.

  10. Ontogenetic behavior and migration of Volga River Russian sturgeon, Acipenser gueldenstaedtii, with a note on adaptive significance of body color

    USGS Publications Warehouse

    Kynard, B.; Zhuang, P.; Zhang, L.; Zhang, T.; Zhang, Z.

    2002-01-01

    We conducted laboratory experiments with Volga River Russian sturgeon, Acipenser gueldenstaedtii, to develop a conceptual model of early behavior. We daily observed fish from day-0 (embryos, first life interval after hatching) to day-29 feeding larvae for preference of bright habitat and cover, swimming distance above the bottom, up- and downstream movement, and diel activity. Hatchling embryos initiated a downstream migration, which suggests that predation risk of embryos at spawning sites is high. Migration peaked on days 0-5 and ceased on day 7 (8-day migration). Migrants preferred bright, open habitat and early migrants swam-up far above the bottom (maximum daily median, 140 cm) in a vertical swim tube. Post-migrant embryos did not prefer bright illumination but continued to prefer white substrate, increased use of cover habitat, and swam on the bottom. Larvae initiated feeding on day 10 after 170.6 cumulative temperature degree-days. Larvae did not migrate, weakly preferred bright illumination, preferred white substrate and open habitat, and swam near the bottom (daily median 5-78 cm). The lack of a strong preference by larvae for bright illumination suggests foraging relies more on olfaction than vision for locating prey. A short migration by embryos would disperse wild sturgeon from a spawning area, but larvae did not migrate, so a second later migration by juveniles disperses young sturgeon to the sea (2-step migration). Embryo and larva body color was light tan and tail color was black. The migration, behavior, and light body color of Russian sturgeon embryos was similar to species of Acipenser and Scaphirhynchus in North America and to Acipenser in Asia that migrate after hatching as embryos. The similarity in migration style and body color among species with diverse phylogenies likely reflects convergence for common adaptations across biogeographic regions. ?? 2002 Kluwer Academic Publishers.

  11. The Effect on the Flow Conditions of Chinese Sturgeons’ Spawning Sites in the Process of Peak Regulation between the Three Gorges Dam and Gezhou Dam

    NASA Astrophysics Data System (ADS)

    Hui, Guo; Minghai, Huang; Feng, Jin

    Chinese sturgeon (Acipenser sinensis Gray) is a kind of key protected fish in ChangJiang river. Recently the Three Gorges dam has run, the peak regulation process between the two dams has serious effect on the formed spawning sites. Based on the previous research results of suitable flow conditions about the spawning sites, this article builds a 2-D shallow water numerical model, calculates the flow conditions of the spawning sites in the process of peak regulation. The results show that the water depth and velocity are various and affect the spawning sites in one 24-hours process of peak regulation, as a whole, when the discharge is below 9000 m3/s and 7500 m3/s respectively, the two spawning sites will be affected seriously.

  12. Movement and habitat use of green sturgeon Acipenser medirostris in the Rogue River, Oregon, USA

    USGS Publications Warehouse

    Erickson, D.L.; North, J.A.; Hightower, J.E.; Weber, J.; Lauck, L.

    2002-01-01

    Green sturgeon (Acipenser medirostris) movement patterns and habitat use within the Rogue River, Oregon were evaluated using radio telemetry. Nineteen specimens ranging from 154 to 225 cm total length were caught by gill netting and tagged with radio transmitters during May-July 2000. One tagged green sturgeon was verified as a female near spawning condition. Individual green sturgeons spent more than 6 months in fresh water and traveled as far as river kilometer (rkm) 39.5. Green sturgeon preferred specific holding sites within the Rogue River during summer and autumn months. These sites were typically deep (> 5 m) low-gradient reaches or off-channel coves. Home ranges within holding sites were restricted. All tagged individuals emigrated from the system to the sea during the autumn and winter, when water temperatures dropped below 10??C and flows increased. This species is extremely vulnerable to habitat alterations and overfishing because it spawns in only a few North American rivers and individuals reside within extremely small areas for extended periods of time.

  13. Effects of incubation substrates on hatch timing and success of White Sturgeon (Acipenser transmontanus) embryos

    USGS Publications Warehouse

    Parsley, Michael J.; Kofoot, Eric

    2013-01-01

    The Kootenai River white sturgeon (Acipenser transmontanus) was listed as endangered under the Endangered Species Act in 1994 because several decades of failed spawning had put the population at risk of extinction. Natural spawning is known to occur at several locations in the Kootenai River, Idaho, but there is little natural recruitment. Microhabitat where embryo incubation occurs is known to be an important factor in white sturgeon reproductive success. This study was conducted to address questions regarding the suitability of different substrates as egg attachment and incubation sites for these fish. A comparative laboratory study using six types of incubation substrates—clean river rocks, periphyton- and algae-covered rocks, waterlogged wood, sand, riparian vegetation, and clean glass plates—tested the hypothesis that survival to hatch of white sturgeon eggs differs among incubation substrates. The results showed that sand was unsuitable as an incubation substrate, as the adhesive embryos were easily dislodged. Periphyton- and algae-covered rocks had the lowest hatch success, and all other substrates had similar hatch success.

  14. Genetic mixed-stock analysis of Atlantic sturgeon Acipenser oxyrinchus oxyrinchus in a heavily exploited marine habitat indicates the need for routine genetic monitoring.

    PubMed

    Dunton, K J; Chapman, D; Jordaan, A; Feldheim, K; O'Leary, S J; McKown, K A; Frisk, M G

    2012-01-01

    Although a previous genetic mixed-stock analysis (gMSA) conducted in the early 1990s showed that marine-captured New York Bight Atlantic sturgeon Acipenser oxyrinchus oxyrinchus almost exclusively originated from the Hudson River, fish from southern U.S. rivers were well represented within this contemporary sample (n = 364 fish), at least during the autumn. Widely distributed spawning stocks are therefore exposed to heavy fishing activity and habitat degradation in this relatively small area, illustrating the need for spatial management across multiple management jurisdictions and routine gMSA to account for temporal change. PMID:22220899

  15. Inactivation of murine norovirus-1 in the edible seaweeds Capsosiphon fulvescens and Hizikia fusiforme using gamma radiation.

    PubMed

    Park, Shin Young; Kang, Sujin; Ha, Sang-Do

    2016-06-01

    This study investigated the effects of gamma radiation (3-10 kGy) upon the inactivation of murine norovirus-1 (MNV-1), a human norovirus (NoV) surrogate. The edible green and brown algae, fulvescens (Capsosiphon fulvescens) and fusiforme (Hizikia fusiforme), respectively, were experimentally contaminated with 5-6 log10 plaque forming units (PFU)/ml MNV-1. The titer of MNV-1 significantly decreased (P < 0.05) as the dose of gamma radiation increased. MNV-1 titer decreased to 1.16-2.46 log10 PFU/ml in fulvescens and 0.37-2.21 log10 PFU/ml in fusiforme following irradiation. However, all Hunters ('L', 'a' and 'b') and sensory qualities (appearance, color, flavor, texture and overall acceptability) were not significantly (P > 0.05) different in both algae following gamma radiation. The Weibull model was used to generate non-linear survival curves and to calculate Gd values for 1, 2, and 3 log10 reductions of MNV-1 in fulvescens (R(2) = 0.992) and fusiforme (R(2) = 0.988). A Gd value of 1 (90% reduction) corresponded to 2.89 and 3.93 kGy in fulvescens and fusiforme, respectively. A Gd value of 2 (99% reduction) corresponded to 7.75 and 9.02 kGy in fulvescens and fusiforme, respectively, while a Gd value of 3 (99.9% reduction) in fulvescens and fusiforme corresponded with 13.83 and 14.93 kGy of gamma radiation, respectively. A combination of gamma radiation at medium doses and other treatments could be used to inactivate ≥ 3 log10 PFU/ml NoV in seaweed. The inactivation kinetics due to gamma radiation against NoV in these algae might provide basic information for use in seaweed processing and distribution. PMID:26919820

  16. Swimming capability and swimming behavior of juvenile acipenser schrenckii.

    PubMed

    Cai, Lu; Taupier, Rachel; Johnson, David; Tu, Zhiying; Liu, Guoyong; Huang, Yingping

    2013-03-01

    Acipenser schrenckii, the Amur Sturgeon, was a commercially valuable fish species inhabiting the Amur (Heilongjiang) River but populations have rapidly declined in recent years. Dams impede A. schrenckii spawning migration and wild populations were critically endangered. Building fishways helped maintain fish populations but data on swimming performance and behavior was crucial for fishway design. To obtain such data on A. schrenckii, a laboratory study of juvenile A. schrenckii (n = 18, body mass = 32.7 ± 1.2 g, body length = 18.8 ± 0.3 cm) was conducted using a stepped velocity test carried out in a fish respirometer equipped with a high-speed video camera at 20°C. Results indicate: (1) The counter-current swimming capability of A. schrenckii was low with critical swimming speed of 1.96 ± 0.10 BL/sec. (2) When a linear function was fitted to the data, oxygen consumption, as a function of swimming speed, was determined to be MO2  = 337.29 + 128.10U (R(2)  = 0.971, P < 0.001) and the power value (1.0) of U indicated high swimming efficiency. (3) Excess post-exercise oxygen cost was 48.44 mgO2 /kg and indicated excellent fatigue recovery. (4) Cost of transport decreased slowly with increased swimming speed. (5) Increased swimming speed led to increases in the tail beat frequency and stride length. This investigation contributed to the basic science of fish swimming behavior and provided data required for the design of fishways. Innovative methods have allowed cultivation of the species in the Yangtze River and, if effective fishways could be incorporated into the design of future hydropower projects on the Amur River, it would contribute to conservation of wild populations of A. schrenckii. The information provided here contributes to the international effort to save this critically endangered species. J. Exp. Zool. 319A:149-155, 2013. © 2013 Wiley Periodicals, Inc. PMID:23359615

  17. Recovery of white sturgeon populations through natural production: Understanding the influence of abiotic and biotic factors on spawning and subsequent recruitment

    USGS Publications Warehouse

    Parsley, M.J.; Anders, P.J.; Miller, A.I.; Beckman, L.G.; McCabe, G.T., Jr.

    2002-01-01

    Recovery or maintenance of sturgeon populations through natural production in perturbed rivers requires adequate knowledge of the abiotic and biotic factors that influence spawning and cause mortality of embryonic, larval, and juvenile life stages. Although it is known that year-class strength of white sturgeon Acipenser transmontanus is determined within 2-3 months after spawning, little is known about specific causes of mortality to early life stages during this period. Initial spawning success is critical in the development of a strong year-class, and maximized recruitment may be dependent upon water temperature and the availability of optimal in-river habitat. Analyses have shown that increased river discharge combined with suitable water temperatures during spawning, egg incubation, yolk sac larvae dispersal, and first exogenous feeding result in greater recruitment. However, little is known about the importance of other variables, such as food availability or losses due to predation that influence year-class strength. ?? 2002 by the American Fisheries Society.

  18. Population origin of Atlantic sturgeon Acipenser oxyrinchus oxyrinchus by-catch in U.S. Atlantic coast fisheries.

    PubMed

    Wirgin, I; Maceda, L; Grunwald, C; King, T L

    2015-04-01

    Microsatellite DNA and mitochondrial DNA control-region sequence analyses were used to determine the population and distinct population segment (DPS) origin of 173 Atlantic sturgeon Acipenser oxyrinchus oxyrinchus encountered from the Gulf of Maine to Cape Hatteras, North Carolina, in NOAA's Northeast Fisheries Observer Program. It was found that the Hudson River was by far the greatest contributor to this coastal by-catch, with 42·2-46·3% of specimens originating there. Generally, specimens represented the geographic province of the river in which they were spawned, but some specimens, particularly those originating in the South Atlantic DPS, moved to great distances. Genetic mixed-stock analyses provide an accurate approach to determine the DPS and population origin of A. o. oxyrinchus by-catch in coastal waters, but most informative management requires that these results be partitioned by locale, season, target fishery and gear type. PMID:25727098

  19. Ontogenetic behavior and migration of Dabry's sturgeon, Acipenser dabryanus, from the Yangtze River, with notes on body color and development rate

    USGS Publications Warehouse

    Kynard, B.; Zhuang, P.; Zhang, T.; Zhang, L.

    2003-01-01

    We conducted laboratory experiments with Dabry's sturgeon, Acipenser dabryanus, from the upper Yangtze River to develop a conceptual model of early behavior. We daily observed fish from day-0 (embryo, first life interval after hatching) to day-30 feeding larva for preference of bright habitat and cover, swimming distance above the bottom, up- and down-stream movement, and diel activity. Hatchling to day-12 embryos and days 13-24 larvae were similar for ontogenetic behavior, i.e., neither initiated a dispersal migration, both swam within 15 cm of the bottom, both preferred bright habitat, and neither strongly preferred cover or open habitat. Embryos and larvae were weakly active day and night. Days 72-76 juveniles had a weak nocturnal downstream migration, indicating wild juveniles disperse from a spawning site. In other sturgeon species yet studied representing three genera on three continents, Dabry's sturgeon is the first that does not disperse as an embryo or larva. Development of Dabry's sturgeon is slow, requiring more cumulative temperature degree days per millimeter of larvae TL than is required for other sturgeons to develop into larvae. Thus, a dispersal migration that diverts energy from development may not be adaptive. The available information suggests the initial dispersal of early life intervals is likely done by females, which spawn in a dispersed spawning style, not the usual aggregated spawning style. Juvenile migrants had a black body and tail with a light line along the lateral scutes. The color of juvenile migrants shows that a dark body and tail is characteristic of Acipenser that migrate downstream as larvae or juveniles.

  20. Impact of the Three Gorges Dam on the spawning stock and natural reproduction of Chinese sturgeon in Changjiang River, China

    NASA Astrophysics Data System (ADS)

    Gao, Xin; Lin, Pengcheng; Li, Mingzheng; Duan, Zhonghua; Liu, Huanzhang

    2016-09-01

    Chinese sturgeon ( Acipenser sinensis) is the flagship species of the Changjiang River. The migration route of this species is blocked by the first dam, the Gezhou Dam, and its reproduction is affected by the Three Gorges Dam (TGD), one of the largest dams in the world. We studied the impact of the impoundment of the Three Gorges Reservoir (TGR) since 2003 on the spawning stock and the natural reproduction of the Chinese sturgeon by using our monitoring data from 1997 to 2013. Results indicate that TGR impoundment has delayed the first spawning dates of the fish from middle-late October to late November, decreased the amount of spawning activities from twice to only once each year, and significantly reduced egg production. In particular, the fish did not demonstrate any spawning activities in 2013. Therefore, TGR impoundment significantly affects the natural reproduction of the fish downstream of the TGD. The spawning stock size of the fish is also predicted to further decrease in the future, which will lead to a risk of population extinction. Ecological regulations must be imposed on decreasing the water temperature to 20°C before mid-October and increasing water discharge downstream of the TGD in October to induce spawning of the Chinese sturgeon.

  1. Impact of the Three Gorges Dam on the spawning stock and natural reproduction of Chinese sturgeon in Changjiang River, China

    NASA Astrophysics Data System (ADS)

    Gao, Xin; Lin, Pengcheng; Li, Mingzheng; Duan, Zhonghua; Liu, Huanzhang

    2016-01-01

    Chinese sturgeon (Acipenser sinensis) is the flagship species of the Changjiang River. The migration route of this species is blocked by the first dam, the Gezhou Dam, and its reproduction is affected by the Three Gorges Dam (TGD), one of the largest dams in the world. We studied the impact of the impoundment of the Three Gorges Reservoir (TGR) since 2003 on the spawning stock and the natural reproduction of the Chinese sturgeon by using our monitoring data from 1997 to 2013. Results indicate that TGR impoundment has delayed the first spawning dates of the fish from middle-late October to late November, decreased the amount of spawning activities from twice to only once each year, and significantly reduced egg production. In particular, the fish did not demonstrate any spawning activities in 2013. Therefore, TGR impoundment significantly affects the natural reproduction of the fish downstream of the TGD. The spawning stock size of the fish is also predicted to further decrease in the future, which will lead to a risk of population extinction. Ecological regulations must be imposed on decreasing the water temperature to 20°C before mid-October and increasing water discharge downstream of the TGD in October to induce spawning of the Chinese sturgeon.

  2. Kootenai River White Sturgeon Investigations; White Sturgeon Spawning and Recruitment Evaluation, 1999 Annual Report.

    SciTech Connect

    Paragamian, Vaughn L.; Kruse, Gretchen L.; Wakkinen, Virginia

    2001-11-01

    Sampling for adult Kootenai River white sturgeon Acipenser transmontanus began in March and continued through April 1999. Forty-six adult sturgeon were captured with 4,091 hours of angling and set-lining effort, while an additional three adult sturgeon were captured during gillnetting for juveniles. Flows for Kootenai River white sturgeon spawning were expected to be high because the snow pack in the basin was estimated at 130% of normal, but runoff came very slowly. Discharge from Libby Dam from mid-March through mid-June was maintained at 113 m{sup 3}/s (4,000 cfs). Flows in the Kootenai River at Bonners Ferry during early April, including local inflow, were 227-255 m{sup 3}/s (8,000-9,000 cfs) but increased gradually in late April to a peak of 657 m{sup 3}/s (23,200 cfs). Flows subsided in early May to about 340 m{sup 3}/s (12,000 cfs), but rose to 1,031 m{sup 3}/s (36,370 cfs) by Mary 26 because of local runoff, and white sturgeon began spawning. However, flows subsided again to 373 m{sup 3}/s (13,200 cfs) June 11, 1999 and some female white sturgeon with transmitters began leaving the spawning reach. Water temperature ranged from about 8 C to 10 C (45 F to 50 F) during these two weeks. On June 13 (two weeks after sturgeon began spawning), spawning and incubation flows from Libby Dam began. The flow was brought up to 1,136 m{sup 3}/s (40,100 cfs) and temperature rose to about 11 C (52 F). They sampled for 3,387 mat days (one mat day is a single 24 h set) with artificial substrate mats and captured 184 white sturgeon eggs. The Middle Shorty's Island reach (river kilometer [rkm] 229.6-231.5) produced the most eggs (144), with 388 mat days of effort; the Refuge section (rkm 234.8 to 237.5) with 616 mat days of effort produced 23 eggs; and the Lower Shorty's section produced 19 eggs with 548 days of mat effort. No eggs were collected above the Refuge section (> rkm 240.5) with 988 mat days of effort. They do not believe flows for sturgeon spawning in 1999 were very

  3. Kootenai river velocities, depth, and white sturgeon spawning site selection - A mystery unraveled?

    USGS Publications Warehouse

    Paragamian, V.L.; McDonald, R.; Nelson, G.J.; Barton, G.

    2009-01-01

    The Kootenai River white sturgeon Acipenser transmontanus population in Idaho, US and British Columbia (BC), Canada became recruitment limited shortly after Libby Dam became fully operational on the Kootenai River, Montana, USA in 1974. In the USA the species was listed under the Endangered Species Act in September of 1994. Kootenai River white sturgeon spawn within an 18-km reach in Idaho, river kilometer (rkm) 228.0-246.0. Each autumn and spring Kootenai River white sturgeon follow a 'short two-step' migration from the lower river and Kootenay Lake, BC, to staging reaches downstream of Bonners Ferry, Idaho. Initially, augmented spring flows for white sturgeon spawning were thought to be sufficient to recover the population. Spring discharge mitigation enhanced white sturgeon spawning but a series of research investigations determined that the white sturgeon were spawning over unsuitable incubation and rearing habitat (sand) and that survival of eggs and larvae was negligible. It was not known whether post-Libby Dam management had changed the habitat or if the white sturgeon were not returning to more suitable spawning substrates farther upstream. Fisheries and hydrology researchers made a team effort to determine if the spawning habitat had been changed by Libby Dam operations. Researchers modeled and compared velocities, sediment transport, and bathymetry with post-Libby Dam white sturgeon egg collection locations. Substrate coring studies confirmed cobbles and gravel substrates in most of the spawning locations but that they were buried under a meter or more of post-Libby Dam sediment. Analysis suggested that Kootenai River white sturgeon spawn in areas of highest available velocity and depths over a range of flows. Regardless of the discharge, the locations of accelerating velocities and maximum depth do not change and spawning locations remain consistent. Kootenai River white sturgeon are likely spawning in the same locations as pre-dam, but post-Libby Dam

  4. Reconstructing the Phylogeny of Capsosiphon fulvescens (Ulotrichales, Chlorophyta) from Korea Based on rbcL and 18S rDNA Sequences

    PubMed Central

    Sun, Sang-Mi; Yang, Seung Hwan

    2016-01-01

    Capsosiphon fulvescens is a filamentous green algae in the class Ulvophyceae. It has been consumed as food with unique flavor and soft texture to treat stomach disorders and hangovers, and its economic value justifies studying its nutritional and potential therapeutic effects. In contrast to these applications, only a few taxonomic studies have been conducted on C. fulvescens. In particular, classification and phylogenetic relationships of the C. fulvescens below the order level are controversial. To determine its phylogenetic position in the class, we used rbcL and 18S rDNA sequences as molecular markers to construct phylogenetic trees. The amplified rbcL and 18S rDNA sequences from 4 C. fulvescens isolates (Jindo, Jangheung, Wando, and Koheung, Korea) were used for phylogenetic analysis by employing three different phylogenetic methods: neighbor joining (NJ), maximum parsimony (MP), and maximum likelihood (ML). The rbcL phylogenetic tree showed that all taxa in the order Ulvales were clustered as a monophyletic group and resolved the phylogenetic position of C. fulvescens in the order Ulotrichales. The significance of our study is that the 18S rDNA phylogenetic tree shows the detailed taxonomic position of C. fulvescens. In our result, C. fulvescens is inferred as a member of Ulotrichaceae, along with Urospora and Acrosiphonia. PMID:27190985

  5. Kootenai River White Sturgeon Investigations; White Sturgeon Spawning and Recruitment Evaluation, 1996 Annual Report.

    SciTech Connect

    Paragamian, Vaughn L.

    1997-09-01

    Test flows for Kootenai River white sturgeon Acipenser transmontanus spawning, scheduled for June 1996, were postponed until July. However, an estimated 126% snow pack and unusually heavy precipitation created conditions for sturgeon spawning that were similar to those occurring before construction of Libby Dam. Discharge in the Kootenai River at Bonners Ferry rose to nearly 1,204 m{sup 3}/s (42,500 cfs) during May and water temperature ranged from 5.8 C to 8.4 C (42 F to 47 F). Migration of adult white sturgeon into spawning areas occurred in late May during a rising hydrograph. Discharge and water temperature were rising and had reached approximately 1,077 m{sup 3}/s (38,000 cfs) and 8 C (46 F). Discharge at Bonners Ferry peaked at about 1,397 m{sup 3}/s (49,300 cfs) on June 5. A total of 348 eggs (and one egg shell) were collected with 106,787 h of mat effort during the flow events. The first white sturgeon eggs were collected on June 8 and continued through June 30. Staging of eggs and back-calculating to spawning dates indicated there were at least 18 spawning episodes between June 6 and June 25. Discharge on June 6 was 1,196 m{sup 3}/s (42,200 cfs) and decreased steadily to 850 m{sup 3}/s (30,000 cfs) by June 26. Although sturgeon spawned in the same reach of river that they had during 1994 and 1995, the majority of eggs were found significantly (P = 0.0001) farther upstream than 1994 and 1995 and this in turn may be related to elevation of Kootenay Lake.

  6. POPULATION DYNAMICS OF HARVEST MICE (REITHRODONTOMYS FULVESCENS AND REITHRODONTOMYS MONTANUS) ACROSS A NITROGEN-AMENDED OLD FIELD

    EPA Science Inventory

    We conducted a mark-recapture experiment to examine population dynamics of the fulvous harvest mouse (Reithrodontomys fulvescens) and plains harvest mouse (Reithrodontomys montanus) in response to low-level nitrogen amendments (16.4 kg N/ha/yr) in an old-field g...

  7. Antioxidant Activity of Oxygen Evolving Enhancer Protein 1 Purified from Capsosiphon fulvescens.

    PubMed

    Kim, Eun-Young; Choi, Youn Hee; Lee, Jung Im; Kim, In-Hye; Nam, Taek-Jeong

    2015-06-01

    This study was conducted to determine the antioxidant activity of a protein purified from Capsosiphon fulvescens. The purification steps included sodium acetate (pH 6) extraction and diethylaminoethyl-cellulose, reversed phase Shodex C4P-50 column chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis indicated that the molecular weight of the purified protein was 33 kDa. The N-terminus and partial peptide amino acid sequence of this protein was identical to the sequence of oxygen evolving enhancer (OEE) 1 protein. The antioxidant activity of the OEE 1 was determined in vitro using a scavenging test with 4 types of reactive oxygen species (ROS), including the 2,2-diphenyl-1-picrylhydrazyl radical, hydroxyl radical, superoxide anion, and hydrogen peroxide (H2 O2 ). OEE 1 had higher H2 O2 scavenging activity, which proved to be the result of enzymatic antioxidants rather than nonenzymatic antioxidants. In addition, OEE 1 showed less H2 O2 -mediated ROS formation in HepG2 cells. In conclusion, this study demonstrates that OEE 1 purified from C. fulvescens is an excellent antioxidant. PMID:25944160

  8. Determination of normal values of some blood serum enzymes in Acipenser stellatus Pallas.

    PubMed

    Shahsavani, D; Mohri, M; Gholipour Kanani, H

    2010-03-01

    Hematological studies on fishes have assumed greater significance due to the increasing emphasis on pisciculture and greater awareness of the pollution of natural water resources. Such studies have generally been used as an effective and sensitive index to monitor physiological and pathological changes in fishes, especially in the management of endangered species. This study was undertaken to establish a reference range for six important blood serum enzymes. Serum samples of 40 Acipenser stellatus (20 female and 20 male) were analyzed, and serum enzyme values were determined. The reference ranges for the total samples and also for each sex were determined. The activities of measured enzymes in serum were: aspartate aminotransferase (AST) 265.60 +/- 56.55 IU/l, alanine aminotransferase (ALT) 5.65 +/- 1.18 IU/l, acid phosphatase (ACP) 15.63 +/- 2.59 IU/l, lactate dehydrogenase (LDH) 2007.15 +/- 521.97 IU/l, creatine kinase (CK) 6,596.05 +/- 1,807.19 IU/l, and alkaline phosphatase (ALP) 69.05 +/- 13.04 IU/l. There were significant differences between male and female fish in terms of AST and CK activity (P < 0.05). These may be related to the season of sampling and changing physiological cycles during spawning during which period the sexual hormones and stress are more obvious. However, there were no differences in the activity of ALP, ACP, LDH, and ALT between sexes. The correlations between measured enzymes were also determined. PMID:18982419

  9. Spawning and rearing habitat use by white sturgeons in the Columbia River downstream from McNary Dam

    SciTech Connect

    Parsley, M.J.; Beckman, L.G. )

    1993-03-01

    Spawning and rearing habitats used by white sturgeons Acipenser transmontanus were described from water temperature, depth, and velocity measurements and substrate types present at sites where eggs, larvae, young-of-the-year, and juveniles (ages 1-7) were collected. Spawning and egg incubation occurred in the swiftest water available (mean water column velocity, 0.8-2.8 m/s), which was within 8 km downstream from each of the four main-stem Columbia River dams in our study area. Substrates where spawning occurred mainly cobble, boulder, and bedrock. Yolk-sac larvae were transported by the river currents from spawning areas into deeper areas with lower water velocities and finer substrates. Young-of-the-year white sturgeons were found at depths of 9-57 m, at mean water column velocities of 0.6 m/s and less, and over substrates of hard clay, mud and silt, sand, gravel, and cobble. Juvenile fish were found at depths of 2-58 m, at mean water column velocities of 1.2 m/s and less, and over substrates of hard clay, mud and silt, sand, gravel, cobble, boulder, and bedrock. 38 refs., 9 figs., 2 tabs.

  10. Spawning and rearing Atlantic menhaden

    SciTech Connect

    Hettler, W.F.

    1981-04-01

    Two-year-old Atlantic menhaden (Brevoortia tyrannus) held in the laboratory at ambient temperatures and salinities for more than 1 year, were induced to spawn by injecting first human chorionic gonadotropin and then carp pituitary powder. Spawning took place at temperatures of 16 to 20/sup 0/C in a 2100-L indoor tank modified to recover the buoyant fertilized eggs. Larvae were reared to the juvenile stage on a diet of cultured rotifers (Brachionus plicatilus), sieved wild zooplankton (64 to 500 ..mu..m), brine shrimp (Artemia salina) nauplii, and powdered trout food.

  11. 25 CFR 242.6 - Spawning season.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Spawning season. 242.6 Section 242.6 Indians BUREAU OF... RESERVATION § 242.6 Spawning season. Walleye and northern pike (or pickerel) shall not be taken during their spawning season except for propagation purposes....

  12. 25 CFR 242.6 - Spawning season.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Spawning season. 242.6 Section 242.6 Indians BUREAU OF... RESERVATION § 242.6 Spawning season. Walleye and northern pike (or pickerel) shall not be taken during their spawning season except for propagation purposes....

  13. 25 CFR 242.6 - Spawning season.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Spawning season. 242.6 Section 242.6 Indians BUREAU OF... RESERVATION § 242.6 Spawning season. Walleye and northern pike (or pickerel) shall not be taken during their spawning season except for propagation purposes....

  14. 25 CFR 242.6 - Spawning season.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Spawning season. 242.6 Section 242.6 Indians BUREAU OF... RESERVATION § 242.6 Spawning season. Walleye and northern pike (or pickerel) shall not be taken during their spawning season except for propagation purposes....

  15. 25 CFR 242.6 - Spawning season.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Spawning season. 242.6 Section 242.6 Indians BUREAU OF... RESERVATION § 242.6 Spawning season. Walleye and northern pike (or pickerel) shall not be taken during their spawning season except for propagation purposes....

  16. Moisture Sorption and Thermodynamic Properties of Vacuum-Dried Capsosiphon fulvescens Powder

    PubMed Central

    Zuo, Li; Rhim, Jong-Whan; Lee, Jun Ho

    2015-01-01

    The moisture sorption isotherms of vacuum-dried edible green alga (Capsosiphon fulvescens) powders were determined at 25, 35, and 45°C and water activity (aw) in the range of 0.11~0.94. An inversion effect of temperature was found at high water activity (>0.75). Various mathematical models were fitted to the experimental data, and Brunauer, Emmett, and Teller model was found to be the most suitable model describing the relationship between equilibrium moisture content and water activity (<0.45). Henderson model could also provide excellent agreement between the experimental and predicted values despite of the intersection point. Net isosteric heat of adsorption decreased from 15.77 to 9.08 kJ/mol with an increase in equilibrium moisture content from 0.055 to 0.090 kg H2O/kg solids. The isokinetic temperature (Tβ) was 434.79 K, at which all the adsorption reactions took place at the same rate. The enthalpy-entropy compensation suggested that the mechanism of the adsorption process was shown to be enthalpy-driven. PMID:26451360

  17. Moisture Sorption and Thermodynamic Properties of Vacuum-Dried Capsosiphon fulvescens Powder.

    PubMed

    Zuo, Li; Rhim, Jong-Whan; Lee, Jun Ho

    2015-09-01

    The moisture sorption isotherms of vacuum-dried edible green alga (Capsosiphon fulvescens) powders were determined at 25, 35, and 45°C and water activity (a w) in the range of 0.11~0.94. An inversion effect of temperature was found at high water activity (>0.75). Various mathematical models were fitted to the experimental data, and Brunauer, Emmett, and Teller model was found to be the most suitable model describing the relationship between equilibrium moisture content and water activity (<0.45). Henderson model could also provide excellent agreement between the experimental and predicted values despite of the intersection point. Net isosteric heat of adsorption decreased from 15.77 to 9.08 kJ/mol with an increase in equilibrium moisture content from 0.055 to 0.090 kg H2O/kg solids. The isokinetic temperature (T β) was 434.79 K, at which all the adsorption reactions took place at the same rate. The enthalpy-entropy compensation suggested that the mechanism of the adsorption process was shown to be enthalpy-driven. PMID:26451360

  18. Capsosiphon fulvescens glycoprotein inhibits AGS gastric cancer cell proliferation by downregulating Wnt-1 signaling.

    PubMed

    Kim, Young-Min; Kim, In-Hye; Nam, Taek-Jeong

    2013-11-01

    Previously, we examined various apoptosis pathways in the AGS gastric cancer cell line using Capsosiphon fulvescens glycoprotein (Cf-GP). In this study, we focused on the downregulation of the Wnt-1 signaling pathway and cell cycle arrest. Upregulation of the Wnt signaling pathway has been observed in various cancer cells. The Wnt signal ligand acts in both canonical and non-canonical pathways. Among them, Wnt-1 was dependent on the canonical pathway. Here, we show inhibition of Wnt-1 signaling, β-catenin and transcription factors in AGS cells via Cf-GP. First, we examined the Frizzled receptor and Wnt-1 signal-related proteins including Axin, LRP, β-catenin, APC and GSK-3β. In addition, the expression levels of transcription factors Tcf/LEF were determined by western blot analysis and RT-PCR. Based on the data, we confirmed downregulation of the Wnt-1 signaling pathway by Cf-GP. Also, we determined the expression levels of cell cycle-related proteins cyclin D and c-myc, and looked for cell cycle arrest by cell cycle test analysis. We found that AGS cells arrested in the G0/G1 phase by Cf-GP. These results provide a mechanism of AGS cell inhibition through the downregulation of Wnt-1 signaling by Cf-GP. PMID:23982808

  19. Microbial community assembly and succession on lake sturgeon egg surfaces as a function of simulated spawning stream flow rate.

    PubMed

    Fujimoto, Masanori; Crossman, James A; Scribner, Kim T; Marsh, Terence L

    2013-10-01

    We investigated microbial succession on lake sturgeon (Acipenser fulvescens) egg surfaces over the course of their incubation period as a function of simulated stream flow rate. The primary objective was to characterize the microbial community assembly during succession and to examine how simulated stream flow rate affect the successional process. Sturgeon eggs were reared under three flow regimes; high (0.55 m/s), low (0.18 m/s), and variable (0.35 and 0.11 m/s alternating 12 h intervals). Eggs were collected from each flow regime at different egg developmental stages. Microbial community DNA was extracted from egg surface and the communities were examined using 16S rRNA gene-based terminal restriction fragment length polymorphism and 454 pyrosequencing. Analysis of these datasets using principal component analysis revealed that microbial communities were clustered by egg developmental stages (early, middle, and late) regardless of flow regimes. 454 pyrosequencing data suggested that 90-98 % of the microbial communities were composed of the phyla Proteobacteria and Bacteroidetes throughout succession. β-Protebacteria was more dominant in the early stage, Bacteroidetes became more dominant in the middle stage, and α-Proteobacteria became dominant in the late stage. A total of 360 genera and 5,826 OTUs at 97 % similarity cutoff were associated with the eggs. Midway through egg development, the egg-associated communities of the low flow regime had a higher diversity than those communities developed under high or variable flow regimes. Results show that microbial community turnover occurred during embryogenesis, and stream flow rate influenced the microbial succession processes on the sturgeon egg surfaces. PMID:23857377

  20. Spatial-Temporal Distribution of Hantavirus Rodent-Borne Infection by Oligoryzomys fulvescens in the Agua Buena Region - Panama

    PubMed Central

    Gonzalez, Publio; Cumbrera, Alberto; Rivero, Alina; Avila, Mario; Armién, Aníbal G.; Koster, Frederick; Glass, Gregory

    2016-01-01

    Background Hotspot detection and characterization has played an increasing role in understanding the maintenance and transmission of zoonotic pathogens. Identifying the specific environmental factors (or their correlates) that influence reservoir host abundance help increase understanding of how pathogens are maintained in natural systems and are crucial to identifying disease risk. However, most recent studies are performed at macro-scale and describe broad temporal patterns of population abundances. Few have been conducted at a microscale over short time periods that better capture the dynamical patterns of key populations. These finer resolution studies may better define the likelihood of local pathogen persistence. This study characterizes the landscape distribution and spatio-temporal dynamics of Oligoryzomys fulvescens (O. fulvescens), an important mammalian reservoir in Central America. Methods Information collected in a longitudinal study of rodent populations in the community of Agua Buena in Tonosí, Panama, between April 2006 and December 2009 was analyzed using non-spatial analyses (box plots) and explicit spatial statistical tests (correlograms, SADIE and LISA). A 90 node grid was built (raster format) to design a base map. The area between the nodes was 0.09 km2 and the total study area was 6.43 km2 (2.39 x 2.69 km). The temporal assessment dataset was divided into four periods for each year studied: the dry season, rainy season, and two months-long transitions between seasons (the months of April and December). Results There were heterogeneous patterns in the population densities and degrees of dispersion of O. fulvescens that varied across seasons and among years. The species typically was locally absent during the late transitional months of the season, and re-established locally in subsequent years. These populations re-occurred in the same area during the first three years but subsequently re-established further south in the final year of the

  1. Oceanic migration and spawning of anguillid eels.

    PubMed

    Tsukamoto, K

    2009-06-01

    Many aspects of the life histories of anguillid eels have been revealed in recent decades, but the spawning migrations of their silver eels in the open ocean still remains poorly understood. This paper overviews what is known about the migration and spawning of anguillid species in the ocean. The factors that determine exactly when anguillid eels will begin their migrations are not known, although environmental influences such as lunar cycle, rainfall and river discharge seem to affect their patterns of movement as they migrate towards the ocean. Once in the ocean on their way to the spawning area, silver eels probably migrate in the upper few hundred metres, while reproductive maturation continues. Although involvement of a magnetic sense or olfactory cues seems probable, how they navigate or what routes they take are still a matter of speculation. There are few landmarks in the open ocean to define their spawning areas, other than oceanographic or geological features such as oceanic fronts or seamounts in some cases. Spawning of silver eels in the ocean has never been observed, but artificially matured eels of several species have exhibited similar spawning behaviours in the laboratory. Recent collections of mature adults and newly spawned preleptocephali in the spawning area of the Japanese eel Anguilla japonica have shown that spawning occurs during new moon periods in the North Equatorial Current region near the West Mariana Ridge. These data, however, show that the latitude of the spawning events can change among months and years depending on oceanographic conditions. Changes in spawning location of this and other anguillid species may affect their larval transport and survival, and appear to have the potential to influence recruitment success. A greater understanding of the spawning migration and the choice of spawning locations by silver eels is needed to help conserve declining anguillid species. PMID:20735675

  2. Characterization of serum immunoglobulins in a chondrostean fish, Acipenser baeri.

    PubMed

    Partula, S; Charlemagne, J

    1993-01-01

    The euglobulin fraction of sturgeon (Acipenser baeri) serum was analyzed using electrophoretic and immunoblotting techniques. The major protein of this fraction is an IgM-like molecule composed of equimolar 70-kDa glycosylated H chains and 26-30 kDa L chains. In the absence of a reducing agent, the L and H polypeptides may form (mu 2L2)n high molecular weight polymers, mu 2L2 170-kDa units or L2 dimers. These different bonding patterns suggest some structural heterogeneity in the distribution of cysteine residues along the sturgeon Ig chains. The H chain N-terminal sequence indicates significant homologies with the conserved VHIII subgroup. Heavy chains antigenically different from the 70-kDa H chain were not detected, suggesting that IgM is the only Ig class synthesized by this sturgeon species. PMID:8299850

  3. Anatomical, hormonal and histological descriptions of captive Russian sturgeon (Acipenser gueldenstaedtii) with intersex gonads.

    PubMed

    Jackson, Karen; Hurvitz, Avshalom; Din, Svetlana Yom; Goldberg, Doron; Pearlson, Oren; Degani, Gad; Levavi-Sivan, Berta

    2006-09-15

    Sturgeons are known throughout the world as the source of black caviar. Their declining populations in their native habitats, mainly the Caspian Sea, due to over-fishing for meat and caviar production, destruction of their spawning grounds and water pollution, have led to their introduction into aquaculture in areas with suitable conditions, including Israel. Recently, we noticed an unusual phenomenon in these normally gonochoristic species. Several 5-year-old female sturgeons were found to have one or more testicular sections in each of their two gonads, forming an intersexual gender. Further examination of other fish from the same age group revealed 14% fish with intersex gonads among a population of 5000 fish that had been pre-selected as females. This phenomenon has not been found however in other age groups of Russian sturgeons, cultured at the same facility. Sturgeons are a generally gonochoristic species, and hermaphroditism is only very infrequently observed under natural or normal breeding conditions. Moreover, these rare cases have all been from polluted habitats. The present work is the first description of fish containing intersex gonads in Russian sturgeon (Acipenser gueldenstaedtii). We describe the phenomenon anatomically and histologically, and examine plasma steroid levels and pituitary gonadotropin gene expression by comparing fish with intersex gonads with normal females and males of the same age group. Intersex gonads were typical female ovaries with one or more white testicular components embedded in each. The testis components were not uniform in size or location among the two gonads of each fish or among different fish, and they showed marked differences in distribution. The ovarian component of the intersex gonad was at the pre-vitellogenic stage as in normal females, and the testis component contained spermatids and mature spermatozoa as in normal males of the same age. However, in terms of estradiol and 11-ketotestosterone plasma levels

  4. Toxicity assessment of silver nanoparticles in Persian sturgeon (Acipenser persicus) and starry sturgeon (Acipenser stellatus) during early life stages.

    PubMed

    Banan, Ashkan; Kalbassi Masjed Shahi, Mohammad Reza; Bahmani, Mahmoud; Yazdani Sadati, Mohammad Ali

    2016-05-01

    Silver nanoparticles (AgNPs) are widely used in consumer products mainly due to their antimicrobial action. The rapidly increasing use of nanoparticles (NPs) has driven more attention to their possible ecotoxicological effects. In this study, the acute toxicity of colloidal AgNPs was evaluated during the embryonic stage of Persian sturgeon (Acipenser persicus) and starry sturgeon (Acipenser stellatus) at concentrations of 0, 0.25, 0.5, 1, 2, 4, and 8 mg/L. Fertilized eggs (75 eggs per replicate) were exposed to aforementioned concentrations for 96 h in triplicate. 96-h LC50 values in Persian sturgeon and starry sturgeon were calculated as 0.163 and 0.158 mg/L, respectively. Furthermore, in starry sturgeon, the short-term effects of AgNPs on the hatching rate, survival rate, and Ag accumulation during early life stages (before active feeding commences) were also analyzed at concentrations of 0, 0.025, 0.05, and 0.1 mg/L of colloidal AgNPs. The highest silver accumulation occurred in larvae exposed to 0.1 mg/L AgNPs; however, the body burden of silver did not alter survival rate, and there were no significant differences among treatments. Based on the obtained results from the acute toxicity exposures, AgNPs induced a concentration-dependent toxicity in both species during early life stages, while complementary studies are suggested for investigating their short-term effects in detail. PMID:26873823

  5. Fertility of a spontaneous hexaploid male Siberian sturgeon, Acipenser baerii

    PubMed Central

    2014-01-01

    Background Evolution of sturgeons and paddlefishes (order Acipenseriformes) is inherently connected with polyploidization events which resulted in differentiation of ploidy levels and chromosome numbers of present acipenseriform species. Moreover, allopolyploidization as well as autopolyploidization seems to be an ongoing process in these fishes and individuals with abnormal ploidy levels were occasionally observed within sturgeon populations. Here, we reported occurrence of Siberian sturgeon (Acipenser baerii) male with abnormal ploidy level for this species, accessed its ploidy level and chromosome number and investigate its potential sterility or fertility in comparison with normal individuals of sterlet (A. ruthenus), Russian sturgeon (A. gueldenstaedtii) and Siberian sturgeon (A. baerii). Results Acipenser ruthenus possessed 120 chromosomes, exhibiting recent diploidy (2n), A. gueldenstaedtii and A. baerii had ~245 chromosomes representing recent tetraploidy (4n), and A. baerii male with abnormal ploidy level had ~ 368 chromosomes, indicating recent hexaploidy (6n). Genealogy assessed from the mtDNA control region did not reveal genome markers of other sturgeon species and this individual was supposed to originate from spontaneous 1.5 fold increment in number of chromosome sets with respect to the number most frequently found in nature for this species. Following hormone stimulation, the spontaneous hexaploid male produced normal sperm with ability for fertilization. Fertilization of A. baerii and A. gueldenstaedtii ova from normal 4n level females with sperm of the hexaploid male produced viable, non-malformed pentaploid (5n) progeny with a ploidy level intermediate to those of the parents. Conclusion This study firstly described occurrence of hexaploid individual of A. baerii and confirmed its autopolyploid origin. In addition to that, the first detailed evidence about fertility of spontaneous hexaploid sturgeon was provided. If 1.5 fold increment in

  6. Parasitic infection in various stages life of cultured Acipenser persicus.

    PubMed

    Adel, Milad; Safari, Reza; Yaghoubzadeh, Zahra; Fazli, Hassan; Khalili, Elham

    2016-01-01

    The present study was conducted to evaluate the status of the parasite fauna in Acipenser persicus at different development stages, in order to find prevention protocols for parasitic diseases in this valuable species. For this purpose, sampling from each sex breeder, 10 egg samples, 5-day-old larvae (n = 20), 20-day-old larvae (n = 80) and fingerling of A. persicus (n = 60) released in earthen ponds were done. After the bioassay and preparing wet mount from the internal and external organs, identification was done according to the keys. According to the results, no fauna parasites were isolated from egg samples and 5-day-old larvae; but Trichodina spp. was isolated from 20-day-old larvae. Also, the same protozoan was isolated from fingerling released in earthen ponds, the mean intensity, prevalence and range of contamination by fingerling were higher with compared to 20-day-old larvae. Trichodina sp. and Diplostomum spathaceum were isolated from skin and eyes of females, respectively. However, Trichodina sp. and Ichthyophthirius multifiliis were isolated from skin of male breeders. In this study, no parasites were isolated from internal organs of larves and fingerling but four intestinal parasites included: Cucullanus sphaerocephlaus, Anisakis sp., Skyrjabinopsilus semiarmatus, and Lepto-rhynchoides plagicephalu were isolated from internal organs of breeder. Based on a wide range of parasitic infection observed in various life stages of A. persicus, it seems necessary to consider hygienic and management measures. PMID:27226891

  7. Parasitic infection in various stages life of cultured Acipenser persicus

    PubMed Central

    Adel, Milad; Safari, Reza; Yaghoubzadeh, Zahra; Fazli, Hassan; Khalili, Elham

    2016-01-01

    The present study was conducted to evaluate the status of the parasite fauna in Acipenser persicus at different development stages, in order to find prevention protocols for parasitic diseases in this valuable species. For this purpose, sampling from each sex breeder, 10 egg samples, 5-day-old larvae (n = 20), 20-day-old larvae (n = 80) and fingerling of A. persicus (n = 60) released in earthen ponds were done. After the bioassay and preparing wet mount from the internal and external organs, identification was done according to the keys. According to the results, no fauna parasites were isolated from egg samples and 5-day-old larvae; but Trichodina spp. was isolated from 20-day-old larvae. Also, the same protozoan was isolated from fingerling released in earthen ponds, the mean intensity, prevalence and range of contamination by fingerling were higher with compared to 20-day-old larvae. Trichodina sp. and Diplostomum spathaceum were isolated from skin and eyes of females, respectively. However, Trichodina sp. and Ichthyophthirius multifiliis were isolated from skin of male breeders. In this study, no parasites were isolated from internal organs of larves and fingerling but four intestinal parasites included: Cucullanus sphaerocephlaus, Anisakis sp., Skyrjabinopsilus semiarmatus, and Lepto-rhynchoides plagicephalu were isolated from internal organs of breeder. Based on a wide range of parasitic infection observed in various life stages of A. persicus, it seems necessary to consider hygienic and management measures. PMID:27226891

  8. A comparative gene index for the white sturgeon Acipenser transmontanus.

    PubMed

    Lazzari, Barbara; Mariani, Valentina; Malinverni, Roberto; Caprera, Andrea; Giuffra, Elisabetta

    2008-03-01

    Sturgeons are archaic fishes phylogenetically distinct from Teleosts. They represent an important niche for aquaculture, particularly for the production of caviar and high quality fillets, while many natural populations in various world areas are today threatened by extinction. Knowledge of the sturgeon genome is limited, as it is the case of many other species of interest for fishery, aquaculture and conservation. Sequences from non-normalized libraries of skin and spleen of the American sturgeon (A. transmontanus) produced in our laboratories were analysed via a bioinformatic procedure, and compared to similar resources available for three Teleost species. Data collected during the analyses were stored in a database - the Sturgeon database (db) - that can be queried via a web interface. The Sturgeon db contains a total of 16,404 sequences from Acipenser transmontanus, Ictalurus punctatus, Salmo salar and Takifugu rubripes, each specie being represented by expressed sequence tags (ESTs) from skin and spleen. Data contained in the database are the results of a number of analyses that mostly focus on sequence annotation and intra- and inter-species comparison. Putative SNP sites, tandem repeats, and sequences matching known protein patterns and motifs were also identified. The Sturgeon db is by now the only online resource dedicated to the analysis of A. transmontanus EST sequences, and represents a starting point for the investigation of the genome of sturgeons from a physiological perspective; it will be used to identify polymorphic markers to study, for example, fish pathologies or to survey fish disease resistance, and to produce gene expression arrays. Introduction of sequences from other species in the analysis pipeline allowed inter-species comparisons of transcripts distribution in Gene Ontology categories, as well as orthologs identification, despite the high sturgeon phylogenetic distance from other fish species. As a result of the EST analysis procedure

  9. Structural Features and Anti-coagulant Activity of the Sulphated Polysaccharide SPS-CF from a Green Alga Capsosiphon fulvescens.

    PubMed

    Synytsya, Andriy; Choi, Doo Jin; Pohl, Radek; Na, Ye Seul; Capek, Peter; Lattová, Erika; Taubner, Tomáš; Choi, Ji Won; Lee, Chang Won; Park, Jae Kweon; Kim, Woo Jung; Kim, Sung Min; Lee, Jisun; Park, Yong Il

    2015-12-01

    Previously, we reported that the sulphated polysaccharides (SPS)-CF, a water-soluble polysaccharide isolated and purified from Korean green alga Maesaengi (Capsosiphon fulvescens, Chlorophyta), is a glucuronogalactomannan based mainly on the monosaccharide composition determined by high-performance liquid chromatography (HPLC) analysis after 1-phenyl-3-methyl-5-pyrazolone (PMP) labelling of sugars in the acid (trifluoroacetic acid (TFA)) hydrolyzates of SPS-CF, which showed mannose (55.4 mol %), galactose (25.3 mol %) and glucuronic acid (16.3 mol %) as major sugars (Na et al., Int Immunopharmacol 10:364-370, 2010). However, the results of the present study re-performed for monosaccharide composition of this polysaccharide using, in addition to HPLC of PMP-labelled sugars, other separation methods, i.e. high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD), gas chromatography with flame ionising detection (GC-FID) and thin-layer chromatography (TLC), clearly demonstrated that the most prominent neutral monosaccharides of SPS-CF are xylose (38.6-49.4 mol %) and rhamnose (39.6-45 mol %), while mannose and galactose are present at a much lesser extent or in negligible amount. These extensive monosaccharide analyses, correlation nuclear magnetic resonance (NMR), electrospray ionization mass spectrometry (ESI-MS) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) measurements confirmed the sulphated glucuronorhamnoxylan (ulvan) type of SPS-CF polysaccharide, whose backbone is composed of alternating sequence of 4-linked L-rhamnose-3-sulphate and D-xylose residues (ulvobiose U3s) carrying monomeric D-glucuronic acid or D-glucuronic acid-3-sulphate on O-2 of some L-rhamnose-3-sulphate units as the side chains. The SPS-CF exhibited significant in vitro anti-coagulant activity by which the activated partial thromboplastin time (aPTT) and thrombin time (TT) were significantly prolonged. The results of this

  10. Kootenai River White Sturgeon Investigations; White Sturgeon Spawning and Recruitment Evaluation, 2003-2004 Annual Report.

    SciTech Connect

    Rust, Pete; Wakkinen, Virginia

    2005-06-01

    The objective of this research was to determine the environmental requirements for successful spawning and recruitment of the Kootenai River white sturgeon Acipenser transmontanus population. Annual tasks include monitoring and evaluating the various life stages of Kootenai River white sturgeon. Sampling for adult Kootenai River white sturgeon in 2003 began in March and continued through April. Eighty-one adult white sturgeon were captured with 3,576 hours of angling and set-lining effort in the Kootenai River. Discharge from Libby Dam and river stage at Bonners Ferry in 2003 peaked in May and early June. Flows remained above 500 m{sup 3}/s throughout June, decreased rapidly through mid July, and increased back to near 500 m{sup 3}/s after mid July and through mid August. By late August, flows had decreased to below 400 m{sup 3}/s. We monitored the movements of 24 adult sturgeon in Kootenay Lake, British Columbia (BC) and the Kootenai River from March 15, 2003 to August 31, 2003. Some of the fish were radio or sonic tagged in previous years. Twelve adult white sturgeon were moved upstream to the Hemlock Bar reach (rkm 260.0) and released as part of the Set and Jet Program. Transmitters were attached to seven of these fish, and their movements were monitored from the time of release until they moved downstream of Bonners Ferry. Eight additional radio-tagged white sturgeon adults were located in the traditional spawning reach (rkm 228-240) during May and June. Sampling with artificial substrate mats began May 21, 2003 and ended June 30, 2003. We sampled 717 mat d (a mat d is one 24 h set) during white sturgeon spawning. Three white sturgeon eggs were collected near Shortys Island on June 3, 2003, and five eggs were collected from the Hemlock Bar reach on June 5, 2003. Prejuvenile sampling began June 17, 2003 and continued until July 31, 2003. Sampling occurred primarily at Ambush Rock (rkm 244.0) in an attempt to document any recruitment that might have occurred from

  11. Kootenai River White Sturgeon Investigations : White Sturgeon Spawning and Recruitment Evaluation, 1998 Annual Report.

    SciTech Connect

    Paragamian, Vaughn L.; Kruse, Gretchen L.; Wakkinen, Virginia

    2001-03-01

    Flows in the Kootenai River for white sturgeon Acipenser transmontanus spawning in 1998 were expected to be at a minimum because the snow pack in the basin was only about 79% normal, and local inflow was expected to be very low, <142 m{sup 3}/s (5,000 cfs). Flows in the Kootenai River at Bonners Ferry from late April through early May were at about 425 m{sup 3}/s (15,000 cfs) while water temperature ranged from about 8 to 10 C (45 to 50 F). Spawning and incubation flows from Libby Dam began on May 18 when flow at the dam was brought up to 765 m{sup 3}/s (27,000 cfs). Unusually frequent rains and several enormous storms brought peak flows at Bonners Ferry to over 1,175 m{sup 3}/s (41,500 cfs) on May 27, temperature ranged between 8 and 10.6 C (45 to 51 F). Flow gradually subsided at Bonners Ferry during June and was steady at 708 to 765 m{sup 3}/s (25,000 to 27,000 cfs) while temperature gradually rose to 14.4 C (58 F). Forty-seven adult white sturgeon were captured with 4,220 hours of angling and setlining effort between March 1 and April 15, 1998 by the Idaho Department of Fish and Game (IDFG). Sonic and radio tags were attached to four female and five male sturgeon during this effort. From April 1 through July 31, 1998, a total of 17 fish were monitored specifically for pre-spawn and spawning activities. White sturgeon spawning location, timing, frequency, and habitat were evaluated by sampling for eggs with artificial substrate mats. Four hundred and eighty-four eggs were collected, 393 eggs (81%) were collected on 60 standard mats, and 91 eggs (19%) were collected on seven experimental mats with drift nets. Ten eggs collected with experimental mats were found mixed with sand, suggesting eggs are moving in the lower water column with sand. The middle Shorty's Island reach (rkm 229.6-231.5) produced the most eggs (173) while the Deep Creek section (rkm 237.6-240.5) produced 112 eggs. No eggs were collected above the Deep Creek section (>rkm 240.5). Four hundred

  12. Spatial and temporal variability of macroinvertebrates in spawning and non-spawning habitats during a salmon run in Southeast Alaska.

    PubMed

    Campbell, Emily Y; Merritt, Richard W; Cummins, Kenneth W; Benbow, M Eric

    2012-01-01

    Spawning salmon create patches of disturbance through redd digging which can reduce macroinvertebrate abundance and biomass in spawning habitat. We asked whether displaced invertebrates use non-spawning habitats as refugia in streams. Our study explored how the spatial and temporal distribution of macroinvertebrates changed during a pink salmon (Oncorhynchus gorbuscha) spawning run and compared macroinvertebrates in spawning (riffle) and non-spawning (refugia) habitats in an Alaskan stream. Potential refugia included: pools, stream margins and the hyporheic zone, and we also sampled invertebrate drift. We predicted that macroinvertebrates would decline in riffles and increase in drift and refugia habitats during salmon spawning. We observed a reduction in the density, biomass and taxonomic richness of macroinvertebrates in riffles during spawning. There was no change in pool and margin invertebrate communities, except insect biomass declined in pools during the spawning period. Macroinvertebrate density was greater in the hyporheic zone and macroinvertebrate density and richness increased in the drift during spawning. We observed significant invertebrate declines within spawning habitat; however in non-spawning habitat, there were less pronounced changes in invertebrate density and richness. The results observed may be due to spawning-related disturbances, insect phenology, or other variables. We propose that certain in-stream habitats could be important for the persistence of macroinvertebrates during salmon spawning in a Southeast Alaskan stream. PMID:22745724

  13. Salmon Spawning Effects on Streambed Stability

    NASA Astrophysics Data System (ADS)

    Buxton, T. H.; Buffington, J. M.; Yager, E.; Fremier, A. K.; Hassan, M. A.

    2014-12-01

    Female salmon build nests ("redds") in streambeds to protect their eggs from predation and damage by bed scour. During spawning, streambed material is mixed, fine sediment is winnowed downstream, and sediment is moved into a tailspill mound resembling the shape of a dune. Redd surfaces are coarser and better sorted than unspawned beds, which is thought to increase redd stability because larger grains are heavier and harder to move and sorting leads to higher friction angles for grain mobility. However, spawning also loosens sediment and creates topography that accelerates flow, both of which may increase particle mobility. We address factors controlling the relative stability of redds and unspawned beds using simulated salmon redds and water worked ("unspawned") beds composed of mixed-grain surfaces in a laboratory flume. Results show that simulated spawning lowered packing resistance to particle mobility on redds by an average of 32-39% compared to unspawned beds. Reductions in packing were sufficient to counter the higher inherent stability of relatively coarse, well sorted grains on redds, overall reducing critical shear stress by 8-20% relative to unspawned beds. In addition, boundary shear stress was 13-41% higher on redds due to flow convergence over the tailspill structure. Finally, redd instability relative to unspawned beds was observed in visual measurements of grain mobility, where bed-averaged shear stress was 22% lower at incipient motion and 29% lower at the discharge that mobilized all grain sizes on redds. Results of these complementary observations, along with sediment mass transport rates being nearly five times higher on a redd than an unspawned bed, indicate that redds are unstable compared to unspawned beds. Given these findings, further research is needed to investigate linkages between spawning disturbance and streambed mobility that may affect salmon reproduction in streams, and to assess whether a certain level of bed disturbance from

  14. Testing Geomorphic Controls on Salmonid Spawning Habitat

    NASA Astrophysics Data System (ADS)

    Pfeiffer, A.; Finnegan, N. J.

    2014-12-01

    The physical architecture of a landscape, as recorded in topography, is a major factor driving the spatial distribution of river habitat within a catchment. For this reason, predictive geomorphic models for fluvial characteristics, particularly grain size, have been suggested as possible contributors to salmonid habitat identification efforts. However, to our knowledge, no work has been done to both implement geomorphic predictions of reach-scale grain size and then test those predictions with salmonid habitat use data. We present a physically-based, empirically calibrated approach to predicting grain size distributions from high resolution LiDAR (Light Detection and Ranging)-derived topographic data. This approach builds on previous efforts in that it predicts the full grain size distribution, rather than just median grain size, and incorporates an empirically calibrated shear stress partitioning factor. We use the predicted grain size distributions to calculate the fraction of the bed area movable by salmon of a given size, which we then compare to 7 years of steelhead trout and coho salmon spawning survey data for a 77 km2 watershed along the central California Coast. We find that grain size explains the paucity of spawning in the upper reaches of the drainage, but does not explain variation within the mainstem. In order to explain the residuals in spawning within the mainstem, we turn to the spacing of riffle bedforms. Field surveys of riffle spacing explain 64% of the variation in spawning in these reaches, suggesting that spawning is ultimately limited by the availability of riffles. Because riffle spacing varies systematically with channel width, we show that predicting riffle spacing is feasible with LiDAR data. Taken together, these findings highlight both the value and limitations of a grain-size focused approach to habitat prediction, and suggest that such approaches should be used in concert with predictions of channel bed morphology.

  15. Distribution and movement of shortnose sturgeon (Acipenser brevirostrum) in the Chesapeake Bay

    USGS Publications Warehouse

    Welsh, S.A.; Mangold, M.F.; Skjeveland, J.E.; Spells, A.J.

    2002-01-01

    During a reward program for Atlantic sturgeon (Acipenser oxyrinchus), 40 federally endangered shortnose sturgeon (Acipenser brevirostrum) were captured and reported by commercial fishers between January 1996 and January 2000 from the Chesapeake Bay. Since this is more than double the number of published records of shortnose sturgeon in the Chesapeake Bay between 1876 and 1995, little information has been available on distributions and movement. We used fishery dependent data collected during the reward program to determine the distribution of shortnose sturgeon in the Chesapeake Bay. Sonically-tagged shortnose sturgeon in the Chesapeake Bay and Delaware River were tracked to determine if individuals swim through the Chesapeake and Delaware Canal. Shortnose sturgeon were primarily distributed within the upper Chesapeake Bay. The movements of one individual, tagged within the Chesapeake Bay and later relocated in the canal and Delaware River, indicated that individuals traverse the Chesapeake and Delaware Canal.

  16. Assessing the potential of the European Atlantic sturgeon Acipenser sturio to control bivalve invasions in Europe.

    PubMed

    Ferreira-Rodriguez, N; Gessner, J; Pardo, I

    2016-08-01

    This pilot study explored the potential of juvenile European Atlantic sturgeon Acipenser sturio to feed on two invasive bivalve species, the Asian clam Corbicula fluminea and the Eurasian zebra mussel Dreissena polymorpha. Preliminary results indicate that native A. sturio were feeding on D. polymorpha at a very limited rate and their potential to prevent the establishment of invasive bivalve species, in new and previously invaded areas, is considered limited. PMID:27238016

  17. Mass Spawning in Tropical Reef Corals

    NASA Astrophysics Data System (ADS)

    Harrison, Peter L.; Babcock, Russell C.; Bull, Gordon D.; Oliver, James K.; Wallace, Carden C.; Willis, Bette L.

    1984-03-01

    Synchronous multispecific spawning by a total of 32 coral species occurred a few nights after late spring full moons in 1981 and 1982 at three locations on the Great Barrier Reef, Australia. The data invalidate the generalization that most corals have internally fertilized, brooded planula larvae. In every species observed, gametes were released; external fertilization and development then followed. The developmental rates of externally fertilized eggs and longevities of planulae indicate that planulae may be dispersed between reefs.

  18. Lessons from a Spawning Gravel Rehabilitation Program

    NASA Astrophysics Data System (ADS)

    Pasternack, G. B.; Wheaton, J. M.; Merz, J.

    2002-12-01

    Altered sediment and flow regimes in dammed and regulated rivers limit available spawning habitat to salmonids. River managers have attempted rehabilitation of spawning habitat with gravel augmentation and riffle construction projects, but often neglect well-established conceptual models of geomorphic and ecologic processes, let alone apply them in a predictive manner. Application of such models could not only improve rehabilitation projects, but also serve to further test and evaluate the underlying scientific theories against the rigors of real-world uncertainties. For the past two years a new science-based approach to rehabilitate spawning gravels for salmonids has been under development and testing to overcome these deficiencies. The approach includes a balance of science-based quantitative tools from multiple disciplines and qualitative local knowledge relevant to the region in which it has been applied. In 2001 and 2002 it was used to design and implement the placement of 907 and 2787 metric tons of gravel, respectively, on separate reaches of the lower Mokelumne River in Central California. A long-term monitoring program to quantify outcomes and assess sustainability is on-going. Lessons from these efforts are providing for adaptive management and will be presented.

  19. Outbreak of mortality in Russian (Acipenser gueldenstaedtii) and Siberian (Acipenser baerii) sturgeons associated with sturgeon nucleo-cytoplasmatic large DNA virus.

    PubMed

    Ciulli, S; Volpe, E; Sirri, R; Passalacqua, P L; Cesa Bianchi, F; Serratore, P; Mandrioli, L

    2016-08-15

    Diseased outbreaks with high mortality in farmed sturgeon are a limiting factor to the success of this emerging aquaculture sector in Europe. Thorough investigations of outbreaks can determine the aetiological agents, identify important pathological and epidemiological pathways of infections and pave the way for effective control strategies. A thorough investigation of a mortality outbreak in Russian (Acipenser gueldenstaedtii) and Siberian (Acipenser baerii) sturgeons in Italy, demonstrated the primary involvement of a sturgeon nucleo-cytoplasmic large DNA virus (NCLDV). While, the taxonomy classification of this new virus is still uncertain, its involvement in sturgeon mortality outbreaks in Europe is, for the first time, fully investigated and described. Furthermore, the coinfection of bacteria such as motile Aeromonas spp. and Acinetobacter spp. was reported. Genetic characterisation showed the close relationship between the European sturgeon NCLDV with North American sturgeon NCLDVs. Similarly to the latter, the European sturgeon NCLDV persists in survivors. Furthermore, a systemic distribution of the European sturgeon NCLDV was evident in diseased A. baerii and A. gueldenstaedtii and in recovered A. gueldenstaedtii. These epidemiological and pathological findings will help in the identification of effective control strategies for sturgeon NCLDV infection, which afflicts an important and emerging European aquaculture sector. PMID:27374904

  20. Comparative Mitogenomics of the Assassin Bug Genus Peirates (Hemiptera: Reduviidae: Peiratinae) Reveal Conserved Mitochondrial Genome Organization of P. atromaculatus, P. fulvescens and P. turpis

    PubMed Central

    Zhao, Guangyu; Li, Hu; Zhao, Ping; Cai, Wanzhi

    2015-01-01

    In this study, we sequenced four new mitochondrial genomes and presented comparative mitogenomic analyses of five species in the genus Peirates (Hemiptera: Reduviidae). Mitochondrial genomes of these five assassin bugs had a typical set of 37 genes and retained the ancestral gene arrangement of insects. The A+T content, AT- and GC-skews were similar to the common base composition biases of insect mtDNA. Genomic size ranges from 15,702 bp to 16,314 bp and most of the size variation was due to length and copy number of the repeat unit in the putative control region. All of the control region sequences included large tandem repeats present in two or more copies. Our result revealed similarity in mitochondrial genomes of P. atromaculatus, P. fulvescens and P. turpis, as well as the highly conserved genomic-level characteristics of these three species, e.g., the same start and stop codons of protein-coding genes, conserved secondary structure of tRNAs, identical location and length of non-coding and overlapping regions, and conservation of structural elements and tandem repeat unit in control region. Phylogenetic analyses also supported a close relationship between P. atromaculatus, P. fulvescens and P. turpis, which might be recently diverged species. The present study indicates that mitochondrial genome has important implications on phylogenetics, population genetics and speciation in the genus Peirates. PMID:25689825

  1. Comparative mitogenomics of the assassin bug genus Peirates (Hemiptera: Reduviidae: Peiratinae) reveal conserved mitochondrial genome organization of P. atromaculatus, P. fulvescens and P. turpis.

    PubMed

    Zhao, Guangyu; Li, Hu; Zhao, Ping; Cai, Wanzhi

    2015-01-01

    In this study, we sequenced four new mitochondrial genomes and presented comparative mitogenomic analyses of five species in the genus Peirates (Hemiptera: Reduviidae). Mitochondrial genomes of these five assassin bugs had a typical set of 37 genes and retained the ancestral gene arrangement of insects. The A+T content, AT- and GC-skews were similar to the common base composition biases of insect mtDNA. Genomic size ranges from 15,702 bp to 16,314 bp and most of the size variation was due to length and copy number of the repeat unit in the putative control region. All of the control region sequences included large tandem repeats present in two or more copies. Our result revealed similarity in mitochondrial genomes of P. atromaculatus, P. fulvescens and P. turpis, as well as the highly conserved genomic-level characteristics of these three species, e.g., the same start and stop codons of protein-coding genes, conserved secondary structure of tRNAs, identical location and length of non-coding and overlapping regions, and conservation of structural elements and tandem repeat unit in control region. Phylogenetic analyses also supported a close relationship between P. atromaculatus, P. fulvescens and P. turpis, which might be recently diverged species. The present study indicates that mitochondrial genome has important implications on phylogenetics, population genetics and speciation in the genus Peirates. PMID:25689825

  2. Inter-annual variability of North Sea plaice spawning habitat

    NASA Astrophysics Data System (ADS)

    Loots, C.; Vaz, S.; Koubbi, P.; Planque, B.; Coppin, F.; Verin, Y.

    2010-11-01

    Potential spawning habitat is defined as the area where environmental conditions are suitable for spawning to occur. Spawning adult data from the first quarter (January-March) of the International Bottom Trawl Survey have been used to study the inter-annual variability of the potential spawning habitat of North Sea plaice from 1980 to 2007. Generalised additive models (GAM) were used to create a model that related five environmental variables (depth, bottom temperature and salinity, seabed stress and sediment type) to presence-absence and abundance of spawning adults. Then, the habitat model was applied each year from 1970 to 2007 to predict inter-annual variability of the potential spawning habitat. Predicted responses obtained by GAM for each year were mapped using kriging. A hierarchical classification associated with a correspondence analysis was performed to cluster spawning suitable areas and to determine how they evolved across years. The potential spawning habitat was consistent with historical spawning ground locations described in the literature from eggs surveys. It was also found that the potential spawning habitat varied across years. Suitable areas were located in the southern part of the North Sea and along the eastern coast of England and Scotland in the eighties; they expanded further north from the nineties. Annual survey distributions did not show such northward expansion and remained located in the southern North Sea. This suggests that this species' actual spatial distribution remains stable against changing environmental conditions, and that the potential spawning habitat is not fully occupied. Changes in environmental conditions appear to remain within plaice environmental ranges, meaning that other factors may control the spatial distribution of plaice spawning habitat.

  3. Biannual Spawning and Temporal Reproductive Isolation in Acropora Corals

    PubMed Central

    Gilmour, James P.; Underwood, Jim N.; Howells, Emily J.; Gates, Emily; Heyward, Andrew J.

    2016-01-01

    Coral spawning on the oceanic reef systems of north-western Australia was recently discovered during autumn and spring, but the degree to which species and particularly colonies participated in one or both of these spawnings was unknown. At the largest of the oceanic reef systems, the participation by colonies in the two discrete spawning events was investigated over three years in 13 species of Acropora corals (n = 1,855 colonies). Seven species spawned during both seasons; five only in autumn and one only in spring. The majority of tagged colonies (n = 218) spawned once a year in the same season, but five colonies from three species spawned during spring and autumn during a single year. Reproductive seasonality was not influenced by spatial variation in habitat conditions, or by Symbiodinium partners in the biannual spawner Acropora tenuis. Colonies of A. tenuis spawning during different seasons separated into two distinct yet cryptic groups, in a bayesian clustering analysis based on multiple microsatellite markers. These groups were associated with a major genetic divergence (G”ST = 0.469), despite evidence of mixed ancestry in a small proportion of individuals. Our results confirm that temporal reproductive isolation is a common feature of Acropora populations at Scott Reef and indicate that spawning season is a genetically determined trait in at least A. tenuis. This reproductive isolation may be punctuated occasionally by interbreeding between genetic groups following favourable environmental conditions, when autumn spawners undergo a second annual gametogenic cycle and spawn during spring. PMID:26963249

  4. Lake trout in northern Lake Huron spawn on submerged drumlins

    USGS Publications Warehouse

    Riley, Stephen C.; Binder, Thomas; Wattrus, Nigel J.; Faust, Matthew D.; Janssen, John; Menzies, John; Marsden, J. Ellen; Ebener, Mark P.; Bronte, Charles R.; He, Ji X.; Tucker, Taaja R.; Hansen, Michael J.; Thompson, Henry T.; Muir, Andrew M.; Krueger, Charles C.

    2014-01-01

    Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.

  5. Size of spawning population, residence time, and territory shifts of individuals in the spawning aggregation of a riverine catostomid

    USGS Publications Warehouse

    Grabowski, T.B.; Isely, J.J.

    2008-01-01

    Little is known about the behavior of individual fish in a spawning aggregation, specifically how long an individual remains in an aggregation. We monitored Moxostoma robustum (Cope) (Robust Redhorse) in a Savannah River spawning aggregation during spring 2004 and 2005 to provide an estimate of the total number of adults and the number of males comprising the aggregation and to determine male residence time and movements within a spawning aggregation. Robust Redhorse were captured using prepostioned grid electrofishers, identified to sex, weighed, measured, and implanted with a passive integrated transponder. Spawning aggregation size was estimated using a multiple census mark-and-recapture procedure. The spawning aggregation seemed to consist of approximately the same number of individuals (82-85) and males (50-56) during both years of this study. Individual males were present for a mean of 3.6 ?? 0.24 days (?? SE) during the 12-day spawning period. The mean distance between successive recaptures of individual males was 15.9 ?? 1.29 m (?? SE). We conclude that males establish spawning territories on a daily basis and are present within the spawning aggregation for at least 3-4 days. The relatively short duration of the aggregation may be the result of an extremely small population of adults. However, the behavior of individuals has the potential to influence population estimates made while fish are aggregated for spawning.

  6. Predictions of realised fecundity and spawning time in Norwegian spring-spawning herring ( Clupea harengus)

    NASA Astrophysics Data System (ADS)

    Óskarsson, G. J.; Kjesbu, O. S.; Slotte, A.

    2002-08-01

    Maturing Norwegian spring-spawning (NSS) herring, Clupea harengus, were collected for reproductive analyses along the Norwegian coast prior to the spawning seasons of 1997-2000. Over this time period there was a marked change in weight (W) at length (TL) with 1998 showing extremely low values and 2000 high values in a historical perspective. Potential fecundity, amounting to about 20 000-100 000 developing (vitellogenic) oocytes per fish and positively related to fish size, increased significantly with fish condition. Relative somatic potential fecundity (RF P, number of oocytes per g ovary-free body weight) in NSS herring was found to vary by 35-55% between years. Unexpectedly, females in 2000 showed low RF P-values, possibly due to negative feedback from previous reproductive investments at low condition. A clear threshold value for Fulton's condition factor, K (K=100×W/TL 3), of 0.65-0.70 existed below which there was considerable atresia (resorption of vitellogenic oocytes). Thus, these components of the spawning stock, amounting to 1-46% in the period 1980-1999, obviously contributed relatively little to the total egg production. This was confirmed by low ovary weights and examples of delayed oocyte development in these individuals. An up-to-date atresia model is presented. The established oocyte growth curve, and to a lesser degree the assumed atretic oocytic turnover rate, was critical for the estimation of realised fecundity (number of eggs spawned). Modelled realised fecundity was significantly below observed potential fecundity. Females that had migrated the shortest distance from the over-wintering area, Vestfjorden, northern Norway, were in the poorest condition, had the least developed oocytes and the lowest potential and realised fecundities. In agreement with previously published studies on temporal and spatial changes in gonad weights, those females reaching the main spawning grounds in the south-western part of the coast (Møre) were the most

  7. Evaluating spawning migration patterns and predicting spawning success of shovelnose sturgeon in the Lower Missouri River

    USGS Publications Warehouse

    Wildhaber, M.L.; Holan, S.H.; Davis, G.M.; Gladish, D.W.; DeLonay, A.J.; Papoulias, D.M.; Sommerhauser, D.K.

    2011-01-01

    Approaches using telemetry, precise reproductive assessments, and surgically implanted data storage tags (DSTs) were used in combination with novel applications of analytical techniques for fish movement studies to describe patterns in migratory behavior and predict spawning success of gravid shovelnose sturgeon. From 2004 to 2007, over 300 gravid female shovelnose sturgeon (Scaphirhynchus platorynchus) from the Lower Missouri River, that were expected to spawn in the year they were collected, were surgically implanted with transmitters and archival DSTs. Functional cluster modeling of telemetry data from the spawning season suggested two common migration patterns of gravid female shovelnose sturgeon. Fish implanted from 958 to 1181 river kilometer (rkm) from the mouth of the Missouri River (or northern portion of the Lower Missouri River within 354rkm of the lowest Missouri River dam at rkm 1305) had one migration pattern. Of fish implanted from 209 to 402rkm from the mouth of the Missouri River (or southern portion of the Lower Missouri River), half demonstrated a movement pattern similar to the northern fish while the other half demonstrated a migration pattern that covered more of the river. There was no apparent difference in migration patterns between successful and unsuccessful spawners. Multiple hypotheses exist to explain differences in migratory patterns among fish from different river reaches. Additional work is required to determine if observed differences are due to multiple adapted strategies, environmental alteration, and/or initial tagging date. Hierarchical Bayesian modeling of DST data indicated that variation in depth usage patterns was consistently different between successful and unsuccessful spawners, as indicated by differences in likelihood of switching between high and low variability states. Analyses of DST data, and data collected at capture, were sufficient to predict 8 of 10 non-spawners/incomplete spawners and all 30 spawners in the

  8. Evaluating spawning migration patterns and predicting spawning success of shovelnose sturgeon in the Lower Missouri River

    USGS Publications Warehouse

    Wildhaber, M.L.; Holan, S.H.; Davis, G.M.; Gladish, D.W.; DeLonay, A.J.; Papoulias, D.M.; Sommerhauser, D.K.

    2011-01-01

    Approaches using telemetry, precise reproductive assessments, and surgically implanted data storage tags (DSTs) were used in combination with novel applications of analytical techniques for fish movement studies to describe patterns in migratory behavior and predict spawning success of gravid shovelnose sturgeon. From 2004 to 2007, over 300 gravid female shovelnose sturgeon (Scaphirhynchus platorynchus) from the Lower Missouri River, that were expected to spawn in the year they were collected, were surgically implanted with transmitters and archival DSTs. Functional cluster modeling of telemetry data from the spawning season suggested two common migration patterns of gravid female shovelnose sturgeon. Fish implanted from 958 to 1181 river kilometer (rkm) from the mouth of the Missouri River (or northern portion of the Lower Missouri River within 354 rkm of the lowest Missouri River dam at rkm 1305) had one migration pattern. Of fish implanted from 209 to 402 rkm from the mouth of the Missouri River (or southern portion of the Lower Missouri River), half demonstrated a movement pattern similar to the northern fish while the other half demonstrated a migration pattern that covered more of the river. There was no apparent difference in migration patterns between successful and unsuccessful spawners. Multiple hypotheses exist to explain differences in migratory patterns among fish from different river reaches. Additional work is required to determine if observed differences are due to multiple adapted strategies, environmental alteration, and/or initial tagging date. Hierarchical Bayesian modeling of DST data indicated that variation in depth usage patterns was consistently different between successful and unsuccessful spawners, as indicated by differences in likelihood of switching between high and low variability states. Analyses of DST data, and data collected at capture, were sufficient to predict 8 of 10 non-spawners/incomplete spawners and all 30 spawners in the

  9. Kootenai River White Sturgeon Investigations; White Sturgeon Spawning and Recruitment Evaluation, 2004-2005 Annual Report.

    SciTech Connect

    Rust, Pete; Wakkinen, Virginia

    2006-05-01

    The objective of this research was to determine the environmental requirements for successful spawning and recruitment of the Kootenai River white sturgeon Acipenser transmontanus population. Annual tasks include monitoring and evaluating the response of various life stages of Kootenai River white sturgeon to mitigation flows supplied by the United States Army Corps of Engineers (USACE). Sampling for adult Kootenai River white sturgeon in 2004 began in March and continued into May. One hundred forty-two adult white sturgeon were captured with 4,146 hours of angling and set-lining effort in the Kootenai River. Kootenai River discharge and stage at Bonners Ferry in 2004 peaked in mid December. Discharge remained below 400 cubic meters per second (cms) until June 1; then, because of a systems operations request (SOR), increased and remained between 480 and 540 cms through the end of June. From July through September, discharge ranged from 360 to 420 cms, decreasing to 168 cms by the end of October. Discharge increased again to above 625 cms by November 4 to increase winter storage in Lake Koocanusa and ranged from 310 to 925 cms through the end of December. We monitored the movements of 31 adult sturgeon in Kootenay Lake, British Columbia (BC) and the Kootenai River from mid-March until late August 2004. All telemetered fish were dual tagged with external sonic and radio transmitters, and some of the fish were tagged in previous years. Eighteen of the 31 telemetered adult white sturgeon were released at Hemlock Bar reach (rkm 260.0) as part of a research project to test the feasibility of moving sexually mature adult white sturgeon to areas with habitat types thought to be more suitable for successful egg hatching and early life stage recruitment. Marked fish were monitored from the time of release until they moved downstream of Bonners Ferry. Sampling for white sturgeon eggs with artificial substrate mats began May 3 and ended June 10, 2004. We sampled 650 mat days

  10. 29 CFR 780.113 - Seeds, spawn, etc.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....” Thus, since mushrooms and beans are considered “agricultural or horticultural commodities,” the spawn of mushrooms and bean sprouts are also so considered and the production, cultivation, growing, and harvesting of mushroom spawn or bean sprouts is “agriculture” within the meaning of section 3(f)....

  11. 29 CFR 780.113 - Seeds, spawn, etc.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....” Thus, since mushrooms and beans are considered “agricultural or horticultural commodities,” the spawn of mushrooms and bean sprouts are also so considered and the production, cultivation, growing, and harvesting of mushroom spawn or bean sprouts is “agriculture” within the meaning of section 3(f)....

  12. 29 CFR 780.113 - Seeds, spawn, etc.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....” Thus, since mushrooms and beans are considered “agricultural or horticultural commodities,” the spawn of mushrooms and bean sprouts are also so considered and the production, cultivation, growing, and harvesting of mushroom spawn or bean sprouts is “agriculture” within the meaning of section 3(f)....

  13. 29 CFR 780.113 - Seeds, spawn, etc.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....” Thus, since mushrooms and beans are considered “agricultural or horticultural commodities,” the spawn of mushrooms and bean sprouts are also so considered and the production, cultivation, growing, and harvesting of mushroom spawn or bean sprouts is “agriculture” within the meaning of section 3(f)....

  14. 29 CFR 780.113 - Seeds, spawn, etc.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Seeds, spawn, etc. 780.113 Section 780.113 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL... of Agriculture Agricultural Or Horticultural Commodities § 780.113 Seeds, spawn, etc. Seeds...

  15. MONITORING SPAWNING GRAVEL IN MANAGED FORESTED WATERSHEDS: A PROPOSED PROCEDURE

    EPA Science Inventory

    Silvicultural activities in the Pacific Northwest introduce various levels of sediments and debris into streams, often degrading spawning habitats of salmonid fishes. In these mountain streams spawning takes place in riffles where the water velocity is usually 1.5 to 2.5 ft/sec a...

  16. Dynamic in-lake spawning migrations by female sockeye salmon

    USGS Publications Warehouse

    Young, D.B.; Woody, C.A.

    2007-01-01

    Precise homing by salmon to natal habitats is considered the primary mechanism in the evolution of population-specific traits, yet few studies have focused on this final phase of their spawning migration. We radio tagged 157 female sockeye salmon (Oncorhynchus nerka) as they entered Lake Clark, Alaska, and tracked them every 1-10 days to their spawning locations. Contrary to past research, no specific shoreline migration pattern was observed (e.g., clockwise) nor did fish enter a tributary unless they spawned in that tributary. Tributary spawning fish migrated faster (mean = 4.7 km??day-1, SD = 2.7, vs. 1.6 km??day-1, SD = 2.1) and more directly (mean linearity = 0.8, SD = 0.2, vs. 0.4, SD = 0.2) than Lake Clark beach spawning fish. Although radio-tagged salmon migrated to within 5 km of their final spawning location in an average of 21.2 days (SD = 13.2), some fish migrated five times the distance necessary and over 50 days to reach their spawning destination. These results demonstrate the dynamic nature of this final phase of migration and support studies indicating a higher degree of homing precision by tributary spawning fish. ?? Journal compilation 2007 Blackwell Munksgaard No claim to original US government works.

  17. Deschutes River Spawning Gravel Study, Volume I, Final Report.

    SciTech Connect

    Huntington, Charles W.

    1985-09-01

    Spawning habitat in the Deschutes River was inventoried, gravel permeability and composition were sampled at selected gravel bars, historical flow records for the Deschutes were analyzed, salmon and trout utilization of spawning habitat was examined, and potential methods of enhancing spawning habitat in the river were explored. Some changes in river conditions since the mid-1960's were identified, including a reduction in spawning habitat immediately downstream from the hydroelectric complex. The 1964 flood was identified as a factor which profoundly affected spawning habitat in the river, and which greatly complicated efforts to identify recent changes which could be attributed to the hydrocomplex. A baseline on present gravel quality at both chinook and steelhead spawning areas in the river was established using a freeze-core methodology. Recommendations are made for enhancing spawning habitat in the Deschutes River, if it is independently determined that spawning habitat is presently limiting populations of summer steelhead or fall chinook in the river. 53 refs., 40 figs., 21 tabs.

  18. Lunar and daily spawning rhythms of Senegal sole Solea senegalensis.

    PubMed

    Oliveira, C; Dinis, M T; Soares, F; Cabrita, E; Pousão-Ferreira, P; Sánchez-Vázquez, F J

    2009-07-01

    A periodicity of 29 days was observed in spawning rhythms in Senegal sole Solea senegalensis, with an acrophase around the last quarter and the new moon. In both spring and autumn, a very marked nocturnal spawning rhythm was registered, with spawning beginning after dusk and the acrophase occurring around 2300 hours. When the photoperiod was artificially extended (from 10L:14D to 14L:10D), S. senegalensis synchronized to the new photoperiod: spawning took place after the new 'dusk', the beginning gradually shifting from 2100 to 2300 hours and the acrophase from 2325 to 0032 hours. Under continuous light conditions, fish sustained rhythmicity for 2 days, with an acrophase at 2249 hours, which suggested the existence of an endogenous pacemaker controlling the daily spawning rhythm. These findings provided new insights for better understanding the reproductive physiology of this species and for optimizing the timing protocols of egg collection and larvae production in S. senegalensis aquaculture. PMID:20738482

  19. Is hyporheic flow an indicator for salmonid spawning site selection?

    NASA Astrophysics Data System (ADS)

    Benjankar, R. M.; Tonina, D.; Marzadri, A.; McKean, J. A.; Isaak, D.

    2015-12-01

    Several studies have investigated the role of hydraulic variables in the selection of spawning sites by salmonids. Some recent studies suggest that the intensity of the ambient hyporheic flow, that present without a salmon egg pocket, is a cue for spawning site selection, but others have argued against it. We tested this hypothesis by using a unique dataset of field surveyed spawning site locations and an unprecedented meter-scale resolution bathymetry of a 13.5 km long reach of Bear Valley Creek (Idaho, USA), an important Chinook salmon spawning stream. We used a two-dimensional surface water model to quantify stream hydraulics and a three-dimensional hyporheic model to quantify the hyporheic flows. Our results show that the intensity of ambient hyporheic flows is not a statistically significant variable for spawning site selection. Conversely, the intensity of the water surface curvature and the habitat quality, quantified as a function of stream hydraulics and morphology, are the most important variables for salmonid spawning site selection. KEY WORDS: Salmonid spawning habitat, pool-riffle system, habitat quality, surface water curvature, hyporheic flow

  20. Amphioxus spawning behavior in an artificial seawater facility.

    PubMed

    Theodosiou, Maria; Colin, Audrey; Schulz, Jasmin; Laudet, Vincent; Peyrieras, Nadine; Nicolas, Jean-François; Schubert, Michael; Hirsinger, Estelle

    2011-06-15

    Owing to its phylogenetic position at the base of the chordates, the cephalochordate amphioxus is an emerging model system carrying immense significance for understanding the evolution of vertebrate development. One important shortcoming of amphioxus as a model organism has been the unavailability of animal husbandry protocols to maintain amphioxus adults away from the field. Here, we present the first report of successful maintenance and spawning of Branchiostoma lanceolatum adults in a facility run on artificial seawater. B. lanceolatum has been chosen for this study because it is the only amphioxus species that can be induced to spawn. We provide a step-by-step guide for the assembly of such a facility and discuss the day-to-day operations required for successful animal husbandry of B. lanceolatum adults. This work also includes a detailed description of the B. lanceolatum spawning behavior in captivity. Our analysis shows that the induced spawning efficiency is not sex biased, but increases as the natural spawning season progresses. We find that a minor fraction of the animals undergo phases of spontaneous spawning in the tanks and that this behavior is not affected by the treatment used to induce spawning. Moreover, the induced spawning efficiency is not discernibly correlated with spontaneous spawning in the facility. Last, we describe a protocol for long-term cryopreservation of B. lanceolatum sperm. Taken together, this work represents an important step toward further establishing amphioxus as a laboratory animal making it more amenable to experimental research, and hence assists the coming of age of this emerging model. PMID:21271675

  1. Method of making compost and spawned compost, mushroom spawn and generating methane gas

    SciTech Connect

    Stoller, B.B.

    1981-04-28

    Newly designed ribbon-type mixers provide an improved method for making composts, aerating composts, growing mushroom spawn, generating methane gas, and filling conveyors in the mushroom-growing industry. The mixers may be the double-ribbon type for purely mixing operations or the single-ribbon type for moving the material from one place to another. Both types can operate under pressure. In preparing compost for mushroom growing, operators can first use the airtight mixers for a preliminary anaerobic fermentation to produce methane, then by changing the atmosphere to an oxidizing one, complete the compost preparation under the necessary aerobic conditions.

  2. DISSOLVED OXYGEN, TEMPERATURE, SURVIVAL OF YOUNG AT FISH SPAWNING SITES

    EPA Science Inventory

    Fluctuations of dissolved oxygen concentrations and water temperatures in their natural spawning sites were measured during embryo through larva stages of northern pike (Esox lucius), and during embryo and sac larva stages of bluegills (Lepomis macrochirus) and pumpkinseeds (Lepo...

  3. The influence of spawning periodicity on population connectivity

    NASA Astrophysics Data System (ADS)

    Kough, Andrew S.; Paris, Claire B.

    2015-09-01

    Many coral reef populations exist as discrete habitat patches linked through larval dispersal into a larger network. On these reefs, organisms spawn periodically and release propagules over a range of frequencies. Biophysical models of larval transport examine marine networks, yet particle release frequency needs careful consideration. We describe the time between sequential spawning events as the release interval and define any linkage of modeled larvae between two habitat sites as a connection. We investigate how changing the release interval affects the connectivity networks of three Caribbean species with low- to high-dispersal potential and swimming behavior. We find that spawning periodicity controls the number and persistence of network connections. Further, larval vertical movement behavior stabilizes the network, significantly increasing connections and connection persistence. This work demonstrates the impact of release interval on connectivity networks and underscores including larval behavior with realistic spawning periodicity in biophysical models of larval transport.

  4. Microphytoplankton variations during coral spawning at Los Roques, Southern Caribbean

    PubMed Central

    Zubillaga, Ainhoa L.; Bastidas, Carolina

    2016-01-01

    Phytoplankton drives primary productivity in marine pelagic systems. This is also true for the oligotrophic waters in coral reefs, where natural and anthropogenic sources of nutrients can alter pelagic trophic webs. In this study, microphytoplankton assemblages were characterized for the first time in relation to expected coral spawning dates in the Caribbean. A hierarchical experimental design was used to examine these assemblages in Los Roques archipelago, Venezuela, at various temporal and spatial scales for spawning events in both 2007 and 2008. At four reefs, superficial water samples were taken daily for 9 days after the full moon of August, including days before, during and after the expected days of coral spawning. Microphytoplankton assemblages comprised 100 microalgae taxa at up to 50 cells per mL (mean ± 8 SD) and showed temporal and spatial variations related to the coral spawning only in 2007. However, chlorophyll a concentrations increased during and after the spawning events in both years, and this was better matched with analyses of higher taxonomical groups (diatoms, cyanophytes and dinoflagellates), that also varied in relation to spawning times in 2007 and 2008, but asynchronously among reefs. Heterotrophic and mixotrophic dinoflagellates increased in abundance, correlating with a decrease of the diatom Cerataulina pelagica and an increase of the diatom Rhizosolenia imbricata. These variations occurred during and after the coral spawning event for some reefs in 2007. For the first time, a fresh-water cyanobacteria species of Anabaena was ephemerally found (only 3 days) in the archipelago, at reefs closest to human settlements. Variability among reefs in relation to spawning times indicated that reef-specific processes such as water residence time, re-mineralization rates, and benthic-pelagic coupling can be relevant to the observed patterns. These results suggest an important role of microheterotrophic grazers in re-mineralization of organic

  5. Microphytoplankton variations during coral spawning at Los Roques, Southern Caribbean.

    PubMed

    Cavada-Blanco, Francoise; Zubillaga, Ainhoa L; Bastidas, Carolina

    2016-01-01

    Phytoplankton drives primary productivity in marine pelagic systems. This is also true for the oligotrophic waters in coral reefs, where natural and anthropogenic sources of nutrients can alter pelagic trophic webs. In this study, microphytoplankton assemblages were characterized for the first time in relation to expected coral spawning dates in the Caribbean. A hierarchical experimental design was used to examine these assemblages in Los Roques archipelago, Venezuela, at various temporal and spatial scales for spawning events in both 2007 and 2008. At four reefs, superficial water samples were taken daily for 9 days after the full moon of August, including days before, during and after the expected days of coral spawning. Microphytoplankton assemblages comprised 100 microalgae taxa at up to 50 cells per mL (mean ± 8 SD) and showed temporal and spatial variations related to the coral spawning only in 2007. However, chlorophyll a concentrations increased during and after the spawning events in both years, and this was better matched with analyses of higher taxonomical groups (diatoms, cyanophytes and dinoflagellates), that also varied in relation to spawning times in 2007 and 2008, but asynchronously among reefs. Heterotrophic and mixotrophic dinoflagellates increased in abundance, correlating with a decrease of the diatom Cerataulina pelagica and an increase of the diatom Rhizosolenia imbricata. These variations occurred during and after the coral spawning event for some reefs in 2007. For the first time, a fresh-water cyanobacteria species of Anabaena was ephemerally found (only 3 days) in the archipelago, at reefs closest to human settlements. Variability among reefs in relation to spawning times indicated that reef-specific processes such as water residence time, re-mineralization rates, and benthic-pelagic coupling can be relevant to the observed patterns. These results suggest an important role of microheterotrophic grazers in re-mineralization of organic

  6. Selected heavy metals analysis of Persian sturgeon's (Acipenser persicus) caviar from Southern Caspian Sea.

    PubMed

    Hosseini, S V; Sobhanardakani, S; Tahergorabi, R; Delfieh, P

    2013-09-01

    The present research reports the heavy metal (Fe, Cr, Pb, As, and Co) contamination in caviar of Persian sturgeon (Acipenser persicus) caught from Southern Caspian Sea sampling site using ICP-OES. Heavy metal concentrations (microgram per gram, wet weight; means ± S.D.) in caviar samples were: Fe, 71.33 ± 0. 37; Cr, 0.27 ± 0.019; Pb, <0.01 ± 0.002; As, <0.01 ± 0.002; and Co, <0.01 ± 0.001, respectively. Comparative evaluation of these metals in different samples showed that except Fe, the average concentrations of Cr, Pb, As, and Co are significantly lower than adverse level for the species themselves and for human consumption when compared with FAO/WHO permissible limits. Therefore, their contribution to adverse health effects on human body can be considered as negligibly small. PMID:23824563

  7. Vulnerability of young white sturgeon, Acipenser transmontanus, to predation in the presence of alternative prey

    USGS Publications Warehouse

    Gadomski, D.M.; Parsley, M.J.

    2005-01-01

    We conducted laboratory trials to test the vulnerability of young white sturgeon, Acipenser transmontanus, to predation when an alternative prey was available. In trials with two species of predators, we observed two feeding patterns. When equal numbers of white sturgeon and goldfish, Carassius auratus, were available, prickly sculpins, Cottus asper, ingested more white sturgeon. Conversely, northern pikeminnow, Ptychocheilus oregonensis, ate more juvenile coho salmon, Oncorhynchus kisutch, than white sturgeon in three out of four sets of trials, but ate more white sturgeon in one set of trials. White sturgeon size and the availability of cover did not affect the proportions of prey species ingested. Our results indicate that predation may be affecting survival of white sturgeon larvae and juveniles in the wild and could be one factor limiting recruitment of young-of-the-year white sturgeon in some locations. ?? Springer 2005.

  8. Molecular characterization and expression pattern of dmrt1 in the immature Chinese sturgeon Acipenser sinensis.

    PubMed

    Leng, X Q; Du, H J; Li, C J; Cao, H

    2016-02-01

    In this study, the cDNA of dmrt1 gene from the Chinese sturgeon Acipenser sinensis was isolated and its expression pattern was characterized in different tissues of immature A. sinensis. By real-time quantitative PCR (qrtPCR) analysis, the A. sinensis dmrt1 mRNA was detected mainly in gonad and with a higher level in the testis than the ovary, especially in 3 and 4 year-old samples. This indicated that the dmrt1 expression exhibited gradual testis specificity with development. The subcellular localization analysis indicated that the Dmrt1 protein exists only in germ cells and not in somatic cells. These results suggest that A. sinensis dmrt1 might be a highly specific sex differentiation gene for testis development and spermatogenesis. PMID:26706998

  9. Biological assessment for the shortnose sturgeon, Acipenser brevirostrum Lesueur 1818, the Savannah River Plant

    SciTech Connect

    Muska, C.; Matthews, R.A.

    1983-10-01

    The shortnose sturgeon (Acipenser brevirostrum) is listed as an endangered species in the United States. Prior to 1982, the presence of shortnose sturgeon had not been documented in the middle reaches of the Savannah River. However, shortnose sturgeon larvae were collected in 1982-1983 near the Savannah River Plant (SRP), a US Department of Energy (DOE) facility, as part of the SRP aquatic ecology program. This biological assessment was prepared to evaluate the potential impacts of present and proposed SRP operations on the shortnose sturgeon. This assessment is based on existing information on the life history and habitat preferences of the shortnose sturgeon, a description of the Savannah River Plant including plant operations which may potentially impact the shortnose sturgeon and consultations with local experts. From this information, it is concluded that the existing and proposed operations (specifically L-Reactor operation) of the Savannah River Plant will not affect the continued existence of the shortnose sturgeon the Savannah River.

  10. First report on facultative parthenogenetic activation of eggs in sterlet sturgeon, Acipenser ruthenus.

    PubMed

    Siddique, Mohammad Abdul Momin; Butts, Ian Anthony Ernest; Cosson, Jacky; Linhart, Otomar

    2016-05-01

    This study reported facultative parthenogenetic cleavage development of sterlet sturgeon Acipenser ruthenus eggs and quantified the percentage of parthenogenetically developed eggs in relation to the fertilization ability of different females. When eggs were activated in freshwater, 5.1-13.7% of eggs developed parthenogenetically, while among those activated eggs 3.6-9.4% developed to 2 cells, 0.4-4.5% developed to 4 cells, and 0-0.8% developed to 8 cells. The mean percentage of fertilized and parthenogenetically activated eggs among the females was negatively correlated (R(2)=0.71, p=0.036), which indicates that parthenogenetic activation rate of sterlet eggs depends on the quality of eggs in terms of fertilization rate. PMID:26952761

  11. Fatty acid composition in tissues of the farmed Siberian sturgeon (Acipenser baerii).

    PubMed

    Nieminen, Petteri; Westenius, Eini; Halonen, Toivo; Mustonen, Anne-Mari

    2014-09-15

    The fatty acid (FA) compositions of the diet and diverse tissues of the farmed Siberian sturgeon (Acipenser baerii) were analyzed in detail to assess their nutritional quality. Twelve male fish were sampled for muscle, fat, liver, brain, gill, kidney and gonad and the tissue FA measured by gas-liquid chromatography. The FA profile of the diet diverged from the FA signatures of the tissues, where the sturgeons accumulated particular highly-unsaturated FA (HUFA). They were probably derived from the diet but, as previous studies have shown that fish can also have desaturase enzymes, endogenous synthesis of these FA cannot be excluded. The sturgeon muscle tissue contained HUFA in proportions comparable to those of other fish species that are considered good sources of n-3 polyunsaturated FA. The indices of atherogenicity and thrombogenicity were also within the values considered to be health-promoting. PMID:24767029

  12. Preferred stream discharges for salmon spawning and rearing in Washington

    USGS Publications Warehouse

    Swift, C.H.

    1977-01-01

    Stream discharges preferred by salmon for spawning were determined from relationships between discharge and spawnable area at 84 study reaches on 28 streams in Washington. Preferred discharges for spawning were found statistically equivalent for chinook, pink, and chum salmon. Regression equations developed for estimating discharges preferred by these species for spawning at other stream sites had standard errors of estimate of 40 percent where a relationship with toe-of-bank channel width was used, and 55 percent where basin drainage area was used. Similarly, equations for estimating the preferred discharge for spawning by sockeye and coho salmon (also statistically equivalent) had standard errors of 48 percent using channel width and 61 percent using drainage area. In general, the discharges preferred for spawning by salmon ranged in magnitude from about 0.3 to 11 times the median monthly mean discharges for September and October and about 0.1 to 6 times the median monthly means for November and December--the four months when spawning is greatest. Stream discharges preferred by salmon for rearing were determined from relationships between discharge and wetted perimeter at the study reaches. Those discharges ranged from about 0.7 to 4 times the median monthly mean discharge for September, when low flows are usually most limiting on the rearing capacity of streams. Equations developed for estimating preferred rearing discharges at other stream sites had standard errors of 57 percent using channel width and 81 percent using drainage area. (Woodard-USGS).

  13. Oceanic spawning ecology of freshwater eels in the western North Pacific

    PubMed Central

    Tsukamoto, Katsumi; Chow, Seinen; Otake, Tsuguo; Kurogi, Hiroaki; Mochioka, Noritaka; Miller, Michael J.; Aoyama, Jun; Kimura, Shingo; Watanabe, Shun; Yoshinaga, Tatsuki; Shinoda, Akira; Kuroki, Mari; Oya, Machiko; Watanabe, Tomowo; Hata, Kazuhiro; Ijiri, Shigeho; Kazeto, Yukinori; Nomura, Kazuharu; Tanaka, Hideki

    2011-01-01

    The natural reproductive ecology of freshwater eels remained a mystery even after some of their offshore spawning areas were discovered approximately 100 years ago. In this study, we investigate the spawning ecology of freshwater eels for the first time using collections of eggs, larvae and spawning-condition adults of two species in their shared spawning area in the Pacific. Ovaries of female Japanese eel and giant mottled eel adults were polycyclic, suggesting that freshwater eels can spawn more than once during a spawning season. The first collection of Japanese eel eggs near the West Mariana Ridge where adults and newly hatched larvae were also caught shows that spawning occurs during new moon periods throughout the spawning season. The depths where adults and newly hatched larvae were captured indicate that spawning occurs in shallower layers of 150–200 m and not at great depths. This type of spawning may reduce predation and facilitate reproductive success. PMID:21285957

  14. Activation of the Albino Sterlet Acipenser ruthenus Eggs by UV-Irradiated Bester Hybrid Spermatozoa to Provide Gynogenetic Progeny.

    PubMed

    Fopp-Bayat, D; Ocalewicz, K

    2015-08-01

    Meiotic gynogenesis was induced in the albino form of sterlet Acipenser ruthenus by activation of eggs with UV-irradiated bester (Huso huso x Acipenser ruthenus) spermatozoa followed by inhibition of the second meiotic division performed by a heat shock. Obtained putative gynogenetic progeny were all albinos. The genetic verification based on three microsatellite DNA markers confirmed the only maternal inheritance of the progeny from the gynogenetic experimental groups. Cytogenetic analysis proved the gynogenetic sterlets were diploids. Application of the albino phenotype together with the molecular and the cytogenetic diagnostic approaches enabled to evaluate the efficiency of the spermatozoa irradiation and application of the heat shock to restore diploid state in the gynogenetic zygotes. PMID:25858073

  15. Coral spawning in the Gulf of Oman and relationship to latitudinal variation in spawning season in the northwest Indian Ocean

    PubMed Central

    Howells, E. J.; Abrego, D.; Vaughan, G. O.; Burt, J. A.

    2014-01-01

    Despite a wealth of information on sexual reproduction in scleractinian corals, there are regional gaps in reproductive records. In the Gulf of the Oman in the Arabian Sea, reproductive timing was assessed in four common species of broadcast spawning corals using field surveys of gamete maturity and aquarium observations of spawning activity. The appearance of mature gametes within the same month for Acropora downingi, A. hemprichii, Cyphastrea microphthalma and Platygyra daedalea (≥ 75% of colonies, n = 848) indicated a synchronous and multi-specific spawning season. Based on gamete disappearance and direct observations, spawning predominantly occurred during April in 2013 (75–100% of colonies) and May in 2014 (77–94% of colonies). The difference in spawning months between survey years was most likely explained by sea temperature and the timing of lunar cycles during late-stage gametogenesis. These reproductive records are consistent with a latitudinal gradient in peak broadcast spawning activity at reefs in the northwestern Indian Ocean which occurs early in the year at low latitudes (January to March) and progressively later in the year at mid (March to May) and high (June to September) latitudes. PMID:25501043

  16. Spawning by walleye (Sander vitreus) and white sucker (Catostomus commersoni) in the Detroit River: Implications for spawning habitat enhancement

    USGS Publications Warehouse

    Manny, B.A.; Kennedy, G.W.; Boase, J.C.; Allen, J.D.; Roseman, E.F.

    2010-01-01

    Few active fish spawning grounds have been found in channels connecting the Great Lakes. Here, we describe one near Belle Isle in the Detroit River, part of the channel connecting lakes Huron and Erie. There, in 2005, we collected 1,573 fish eggs, cultured them, and identified the hatched larvae as walleye (Sander vitreus) and white sucker (Catostomus commersoni). Walleye spawning peaked during the week of April 12-19; white sucker spawning peaked on May 10. Average areal rate of egg deposition by walleye and white sucker at this spawning ground in 2005 was 346 and 25 eggs/m2, respectively. Our environmental measurements showed that bottom substrates on this spawning ground were largely sand, not optimal for fish reproduction. We hypothesize that reproduction of these fish at this spawning ground could be enhanced by adding rock and gravel substrates for protection of deposited fish eggs and suggest that reproduction by walleye in the Detroit River may add resilience to production of walleye in western Lake Erie. ?? 2010.

  17. Coral spawning in the Gulf of Oman and relationship to latitudinal variation in spawning season in the northwest Indian Ocean.

    PubMed

    Howells, E J; Abrego, D; Vaughan, G O; Burt, J A

    2014-01-01

    Despite a wealth of information on sexual reproduction in scleractinian corals, there are regional gaps in reproductive records. In the Gulf of the Oman in the Arabian Sea, reproductive timing was assessed in four common species of broadcast spawning corals using field surveys of gamete maturity and aquarium observations of spawning activity. The appearance of mature gametes within the same month for Acropora downingi, A. hemprichii, Cyphastrea microphthalma and Platygyra daedalea (≥ 75% of colonies, n = 848) indicated a synchronous and multi-specific spawning season. Based on gamete disappearance and direct observations, spawning predominantly occurred during April in 2013 (75-100% of colonies) and May in 2014 (77-94% of colonies). The difference in spawning months between survey years was most likely explained by sea temperature and the timing of lunar cycles during late-stage gametogenesis. These reproductive records are consistent with a latitudinal gradient in peak broadcast spawning activity at reefs in the northwestern Indian Ocean which occurs early in the year at low latitudes (January to March) and progressively later in the year at mid (March to May) and high (June to September) latitudes. PMID:25501043

  18. Multiscale hydrogeomorphic influences on bull trout (Salvelinus confluentus) spawning habitat

    USGS Publications Warehouse

    Bean, Jared R; Wilcox, Andrew C.; Woessner, William W; Muhlfeld, Clint C.

    2015-01-01

    We investigated multiscale hydrogeomorphic influences on the distribution and abundance of bull trout (Salvelinus confluentus) spawning in snowmelt-dominated streams of the upper Flathead River basin, northwestern Montana. Within our study reaches, bull trout tended to spawn in the finest available gravel substrates. Analysis of the mobility of these substrates, based on one-dimensional hydraulic modeling and calculation of dimensionless shear stresses, indicated that bed materials in spawning reaches would be mobilized at moderate (i.e., 2-year recurrence interval) high-flow conditions, although the asynchronous timing of the fall–winter egg incubation period and typical late spring – early summer snowmelt high flows in our study area may limit susceptibility to redd scour under current hydrologic regimes. Redd occurrence also tended to be associated with concave-up bedforms (pool tailouts) with downwelling intragravel flows. Streambed temperatures tracked stream water diurnal temperature cycles to a depth of at least 25 cm, averaging 6.1–8.1 °C in different study reaches during the spawning period. Ground water provided thermal moderation of stream water for several high-density spawning reaches. Bull trout redds were more frequent in unconfined alluvial valley reaches (8.5 versus 5.0 redds·km−1 in confined valley reaches), which were strongly influenced by hyporheic and groundwater – stream water exchange. A considerable proportion of redds were patchily distributed in confined valley reaches, however, emphasizing the influence of local physical conditions in supporting bull trout spawning habitat. Moreover, narrowing or “bounding” of these alluvial valley segments did not appear to be important. Our results suggest that geomorphic, thermal, and hydrological factors influence bull trout spawning occurrence at multiple spatial scales.

  19. How coarse is too coarse for salmon spawning substrates?

    NASA Astrophysics Data System (ADS)

    Wooster, J. K.; Riebe, C. S.; Ligon, F. K.; Overstreet, B. T.

    2009-12-01

    Populations of Pacific salmon species have declined sharply in many rivers of the western US. Reversing these declines is a top priority and expense of many river restoration projects. To help restore salmon populations, managers often inject gravel into rivers, to supplement spawning habitat that has been depleted by gravel mining and the effects of dams—which block sediment and thus impair habitat downstream by coarsening the bed where salmon historically spawned. However, there is little quantitative understanding nor a methodology for determining when a river bed has become too coarse for salmon spawning. Hence there is little scientific basis for selecting sites that would optimize the restoration benefits of gravel injection (e.g., sites where flow velocities are suitable but bed materials are too coarse for spawning). To develop a quantitative understanding of what makes river beds too coarse for salmon spawning, we studied redds and spawning use in a series of California and Washington rivers where salmon spawning ability appears to be affected by coarse bed material. Our working hypothesis is that for a given flow condition, there is a maximum “threshold” particle size that a salmon of a given size is able to excavate and/or move as she builds her redd. A second, related hypothesis is that spawning use should decrease and eventually become impossible with increasing percent coverage by immovable particles. To test these hypotheses, we quantified the sizes and spatial distributions of immovably coarse particles in a series of salmon redds in each river during the peak of spawning. We also quantified spawning use and how it relates to percent coverage by immovable particles. Results from our studies of fall-run chinook salmon (Oncorhynchus tshawytsha) in the Feather River suggest that immovable particle size varies as a function of flow velocity over the redd, implying that faster water helps fish move bigger particles. Our Feather River study also

  20. Chemical regulation of spawning in the zebra mussel (Dreissena polymorpha)

    USGS Publications Warehouse

    Ram, Jeffrey L.; Nichols, S. Jerrine

    1992-01-01

    Previous literature suggests that spawning in bivalves is chemically regulated, both by environmental chemical cues and by internal chemical mediators. In a model proposed for zebra mussels, chemicals from phytoplankton initially trigger spawning, and chemicals associated with gametes provide further stimulus for spawning. The response to environmental chemicals is internally mediated by a pathway utilizing serotonin (5-hydroxytryptamine, a neurotransmitter), which acts directly on both male and female gonads. The role of serotonin and most other aspects of the model have been tested only on bivalves other than zebra mussels. The effect of serotonin on zebra mussel spawning was tested. Serotonin (10-5 and 10-3 M) injected into ripe males induced spawning, but injection of serotonin into females did not. Gametes were not released by 10-6 serotonin; in most cases, serotonin injection did not release gametes from immature recipients. Serotonin injection provides a reliable means for identifying ripe male zebra mussels and for obtaining zebra mussel sperm without the need for dissection.

  1. Beach-spawning fishes, terrestrial eggs, and air breathing.

    PubMed

    Martin, K L M; Van Winkle, R C; Drais, J E; Lakisic, H

    2004-01-01

    Many fishes have independently evolved beach spawning with oviposition at the water's edge. These include intertidal, subtidal, and estuarine, as well as a few freshwater, species. Their spectacular reproductive behavior at the boundary of water and land has focused attention on adults, but they emerge either briefly or not at all. The need for air breathing is more apparent in the eggs, and the reasons for emergence are more applicable to eggs than to the adults of most beach-spawning fishes. There is little evidence of air breathing in the adults, unless they are regularly emerged at other times as well. Conversely, eggs metabolize in air and show substantial emergence tolerance. We consider beach spawning a form of parental care in fishes. The adults place eggs so they will be emerged into air during part or all of incubation, providing increased temperatures, oxygen availability, and protection. Beach spawning provides habitat segregation at different points in the life history, with air emergence early in the life cycle and a return to water at hatching. The parents take great risks to spawn at the water's edge to give their offspring the most advantageous beginning in life. PMID:15547793

  2. Oceanic spawning migration of the European eel (Anguilla anguilla).

    PubMed

    Aarestrup, Kim; Okland, Finn; Hansen, Michael M; Righton, David; Gargan, Patrik; Castonguay, Martin; Bernatchez, Louis; Howey, Paul; Sparholt, Henrik; Pedersen, Michael I; McKinley, Robert S

    2009-09-25

    European eels (Anguilla anguilla) undertake a approximately 5000-kilometer (km) spawning migration from Europe to the Sargasso Sea. The larvae are transported back to European waters by the Gulf Stream and North Atlantic Drift. However, details of the spawning migration remain unknown because tracking eels in the Atlantic Ocean has, so far, eluded study. Recent advances in satellite tracking enable investigation of migratory behavior of large ocean-dwelling animals. However, sizes of available tags have precluded tracking smaller animals like European eels. Here, we present information about the swimming direction, depth, and migratory behavior of European eels during spawning migration, based on a miniaturized pop-up satellite archival transmitter. Although the tagging experiment fell short of revealing the full migration to the Sargasso Sea, the data covered the first 1300 km and provided unique insights. PMID:19779192

  3. Detection of estradiol-17β during a mass coral spawn

    NASA Astrophysics Data System (ADS)

    Atkinson, S.; Atkinson, M. J.

    1992-04-01

    The steroid estradiol-17β (E2) is associated with female gametogenesis in all vertebrates and many invertebrates. This is the first report of estrogens in scleractinian corals. Seawater and egg slicks were collected during a mass coral spawn at Ningaloo reef, Western Australia for the measurement of total phosphate (TP) and E2. Total P in the water column increased 600 times, from 0.5μM to 300μM. Concentrations of E2 increased nearly 8 fold during the spawn, from 55 to 420 pg/100 ml seawater. Coral eggs collected from egg slicks contained 368±40 pg E2/g dry wt of eggs. Estrogen may be a key hormone in a simple endocrine system of scleractinian corals that synchronizes growth and development of coral oocytes. Its potential role in triggering spawning via chemical messengers in the water column warrants further research.

  4. Spawning behaviour and post-spawning migration patterns of atlantic bluefin tuna (Thunnus thynnus) ascertained from satellite archival tags.

    PubMed

    Aranda, Guillermo; Abascal, Francisco Javier; Varela, José Luis; Medina, Antonio

    2013-01-01

    Spawning behaviour of Atlantic bluefin tuna (Thunnus thynnus) was investigated using electronic satellite tags deployed in the western Mediterranean spawning ground, around the Balearic Islands (years 2009-2011). All the fish were tagged underwater and released within schools. In general, the fish tagged in the same year/school displayed common migratory trends. Following extended residency around the Balearic Islands, most tagged tuna crossed the Strait of Gibraltar heading for the North Atlantic. Discrepancies between the migratory tracks reconstructed from this and previous electronic tagging studies suggest that the bluefin tuna Mediterranean population may comprise distinct units exhibiting differing migratory behaviours. The diving behaviour varied between oceanic regions throughout the migratory pathways, the shallowest distribution taking place in the spawning ground and the deepest at the Strait of Gibraltar. A unique diving pattern was found on the majority of nights while the fish stayed at the spawning ground; it consisted of frequent and brief oscillatory movements up and down through the mixed layer, resulting in thermal profiles characterized by oscillations about the thermocline. Such a pattern is believed to reflect recent courtship and spawning activity. Reproductive parameters inferred from the analysis of vertical profiles are consistent with those estimated in previous studies based on biological samples. PMID:24098502

  5. Spawning Behaviour and Post-Spawning Migration Patterns of Atlantic Bluefin Tuna (Thunnus thynnus) Ascertained from Satellite Archival Tags

    PubMed Central

    Aranda, Guillermo; Abascal, Francisco Javier; Varela, José Luis; Medina, Antonio

    2013-01-01

    Spawning behaviour of Atlantic bluefin tuna (Thunnus thynnus) was investigated using electronic satellite tags deployed in the western Mediterranean spawning ground, around the Balearic Islands (years 2009-2011). All the fish were tagged underwater and released within schools. In general, the fish tagged in the same year/school displayed common migratory trends. Following extended residency around the Balearic Islands, most tagged tuna crossed the Strait of Gibraltar heading for the North Atlantic. Discrepancies between the migratory tracks reconstructed from this and previous electronic tagging studies suggest that the bluefin tuna Mediterranean population may comprise distinct units exhibiting differing migratory behaviours. The diving behaviour varied between oceanic regions throughout the migratory pathways, the shallowest distribution taking place in the spawning ground and the deepest at the Strait of Gibraltar. A unique diving pattern was found on the majority of nights while the fish stayed at the spawning ground; it consisted of frequent and brief oscillatory movements up and down through the mixed layer, resulting in thermal profiles characterized by oscillations about the thermocline. Such a pattern is believed to reflect recent courtship and spawning activity. Reproductive parameters inferred from the analysis of vertical profiles are consistent with those estimated in previous studies based on biological samples. PMID:24098502

  6. Barriers impede upstream spawning migration of flathead chub

    USGS Publications Warehouse

    Walters, David M.; Zuellig, Robert E.; Crockett, Harry J.; Bruce, James F.; Lukacs, Paul M.; Fitzpatrick, Ryan M.

    2014-01-01

    Many native cyprinids are declining throughout the North American Great Plains. Some of these species require long reaches of contiguous, flowing riverine habitat for drifting eggs or larvae to develop, and their declining populations have been attributed to habitat fragmentation or barriers (e.g., dams, dewatered channels, and reservoirs) that restrict fish movement. Upstream dispersal is also needed to maintain populations of species with passively drifting eggs or larvae, and prior researchers have suggested that these fishes migrate upstream to spawn. To test this hypothesis, we conducted a mark–recapture study of Flathead Chub Platygobio gracilis within a 91-km reach of continuous riverine habitat in Fountain Creek, Colorado. We measured CPUE, spawning readiness (percent of Flathead Chub expressing milt), and fish movement relative to a channel-spanning dam. Multiple lines of evidence indicate that Flathead Chub migrate upstream to spawn during summer. The CPUE was much higher at the base of the dam than at downstream sites; the seasonal increases in CPUE at the dam closely tracked seasonal increases in spawning readiness, and marked fish moved upstream as far as 33 km during the spawning run. The upstream migration was effectively blocked by the dam. The CPUE of Flathead Chub was much lower upstream of the OHDD than at downstream sites, and <0.2% of fish marked at the dam were recaptured upstream. This study provides the first direct evidence of spawning migration for Flathead Chub and supports the general hypothesis that barriers limit adult dispersal of these and other plains fishes.

  7. [Obtaining sturgeon spawn in accordance with the German Pharmaceuticals Act].

    PubMed

    Bräuer, G; Emmerich, I U

    2014-01-01

    Obtaining sturgeon spawn in aquaculture is carried out with different objectives. Sturgeons are increasingly used for ornamental purposes or to serve as food. Previously, sturgeon roe was obtained primarily by surgical opening of the abdomen or during slaughter. Recently, in aquaculture roe has been increasingly produced by stripping off the eggs. In this new method it is necessary to synchronize spawn production by stimulating the fish through hormone usage. Therefore, the complete egg package can be taken from the fish, which avoids resorption disorders. This article discusses how this method can be evaluated from the perspective of drug law. PMID:24518883

  8. Analysis of the association between spawning time QTL markers and the biannual spawning behavior in rainbow trout (Oncorhynchus mykiss)

    PubMed Central

    2010-01-01

    The rainbow trout is a salmonid fish that occasionally exhibits broodstocks with biannual spawning behavior, a phenomenon known as a double annual reproductive cycle (DARC). Spawning time quantitative trait loci (SPT-QTLs) affect the time of the year that female rainbow trout spawn and may influence expression of the DARC trait. In this study, microsatellite markers linked and unlinked to SPT-QTLs were genotyped to investigate the underlying genetics of this trait. SPT-QTLs influenced the DARC trait since in two case-control comparisons three linked markers (OmyFGT12TUF, One3ASC and One19ASC) had significant levels of allelic frequency differentiation and marker-character association. Furthermore, alleles of One3ASC and One19ASC had significantly higher frequencies in populations that carried the DARC trait. PMID:21637435

  9. Evaluation of methods for identifying spawning sites and habitat selection for alosines

    USGS Publications Warehouse

    Harris, Julianne E.; Hightower, Joseph E.

    2010-01-01

    Characterization of riverine spawning habitat is important for the management and restoration of anadromous alosines. We examined the relative effectiveness of oblique plankton tows and spawning pads for collecting the eggs of American shad Alosa sapidissima, hickory shad A. mediocris, and “river herring” (a collective term for alewife A. pseudoharengus and blueback herring A. aestivalis) in the Roanoke River, North Carolina. Relatively nonadhesive American shad eggs were only collected by plankton tows, whereas semiadhesive hickory shad and river herring eggs were collected by both methods. Compared with spawning pads, oblique plankton tows had higher probabilities of collecting eggs and led to the identification of longer spawning periods. In assumed spawning areas, twice-weekly plankton sampling for 15 min throughout the spawning season had a 95% or greater probability of collecting at least one egg for all alosines; however, the probabilities were lower in areas with more limited spawning. Comparisons of plankton tows, spawning pads, and two other methods of identifying spawning habitat (direct observation of spawning and examination of female histology) suggested differences in effectiveness and efficiency. Riverwide information on spawning sites and timing for all alosines is most efficiently obtained by plankton sampling. Spawning pads and direct observations of spawning are the best ways to determine microhabitat selectivity for appropriate species, especially when spawning sites have previously been identified. Histological examination can help determine primary spawning sites but is most useful when information on reproductive biology and spawning periodicity is also desired. The target species, riverine habitat conditions, and research goals should be considered when selecting methods with which to evaluate alosine spawning habitat.

  10. [THE EFFECT OF HORMONAL STIMULATION OF STERLET (ACIPENSER RUTHENUS L.) ON STEROID LEVELS IN TISSUE INCUBATES].

    PubMed

    Bayunova, L V

    2016-01-01

    Sex steroids and corticol levels in Leibovitz's L-15 media samples after incubation of intact female and male sterlet (Acipenser rhutenus L.) tissue fragments and those if fishes treated with a superactive analogue of mammalian luteinising hormone-releasing hormone (LH-RH-A) were compared. 17,20β,21-trihydroxy-4-pregnen-3-one (20βS) levels were significantly higher in the media samples after incubation of ovarian follicles taken from females 5 h after treatment with LH-RH-A in comparison with 20βS levels in intact female samples. 20βS levels also increased after 1 μM progesterone (P4) adding to the media before incubation of ovarian follicles. Cortisol and testosterone levels in the media samples demonstrated the same tendency. Significant elevation of cortisol levels was observed in the blood serum samples of females 5 h after LH-RH-A treatment. The androgens (testosterone and 11-ketotestosterone) levels after incubation of testicular and liver fragments were high in the media samples in males who had high serum levels of these androgens before hormonal stimulation. Sex steroids and cortisol production was stimulated by P4 adding to the media before incubation of gonad fragments. 20βS media levels increased after P4 adding before incubation of liver fragments. PMID:27220236

  11. Fatty acid composition and volatile compounds of caviar from farmed white sturgeon (Acipenser transmontanus).

    PubMed

    Caprino, Fabio; Moretti, Vittorio Maria; Bellagamba, Federica; Turchini, Giovanni Mario; Busetto, Maria Letizia; Giani, Ivan; Paleari, Maria Antonietta; Pazzaglia, Mario

    2008-06-01

    The present study was conducted to characterize caviar obtained from farmed white sturgeons (Acipenser transmontanus) subjected to different dietary treatments. Twenty caviar samples from fish fed two experimental diets containing different dietary lipid sources have been analysed for chemical composition, fatty acids and flavour volatile compounds. Fatty acid make up of caviar was only minimally influenced by dietary fatty acid composition. Irrespective of dietary treatments, palmitic acid (16:0) and oleic acid (OA, 18:1 n-9) were the most abundant fatty acid followed by docosahexaenoic acid (DHA, 22:6 n-3) and eicopentaenoic (EPA, 20:5 n-3). Thirty-three volatile compounds were isolated using simultaneous distillation-extraction (SDE) and identified by GC-MS. The largest group of volatiles were represented by aldehydes with 20 compounds, representing the 60% of the total volatiles. n-Alkanals, 2-alkenals and 2,4-alkadienals are largely the main responsible for a wide range of flavours in caviar from farmed white surgeon. PMID:18486649

  12. Quality attributes and microbial storage stability of caviar from cultivated white sturgeon (Acipenser transmontanus).

    PubMed

    Shin, Joong-Han; Oliveira, Alexandra C M; Rasco, Barbara A

    2010-01-01

    Caviar was prepared from white sturgeon (Acipenser transmontanus) roe by adjusting the water phase salt (WPS) to 4.0% to 6.3% by adding food grade NaCl. Fish were obtained from 2 different farms from the Inland Northwest (N = 5). Salt was absorbed at a different rate and to a different extent by roe from different fish. The lipid content in the fish roe varied from 10.2% to 14.4% (w/w), with palmitic acid and oleic acid being the most abundant saturated and monounsaturated fatty acids present, respectively. The caviar contained high levels of polyunsaturated fatty acids (PUFA) (35% to 37%) with docosahexanoic acid being the most abundant omega-3 long chain fatty acid. There were no significant differences in microbial storage stability for caviars from different fish stored at 3 degrees C. However, for caviar stored at 7 degrees C, there was less growth of Listeria monocytogenes (using a cocktail of ATCC 19114, 7644, 19113 strains) in 2 samples (2B46 and 0F05) until day 20. In 2 other samples (453F and 2519), which had lower initial microbial loads, less overall microbial growth was observed, indicating that culture and harvest practices result in compositional differences between fish, which may impact both product composition and storage stability. PMID:20492148

  13. Adverse health effects and histological changes in white sturgeon (Acipenser transmontanus) exposed to dietary selenomethionine.

    PubMed

    Zee, Jenna; Patterson, Sarah; Gagnon, Danielle; Hecker, Markus

    2016-07-01

    It has been shown that selenium (Se) released to the aquatic environment can have devastating effects on local wildlife. White sturgeon (Acipenser transmontanus) have a life history particularly susceptible to contaminants, and their protection is of interest as they are culturally and economically important, and many populations are classified as endangered. During the present 72-d dietary study, multiple signs of decreased health and Se lethality were observed. Juvenile white sturgeon were given diets containing 1.4 μg, 5.6 μg, 22.4 μg, or 104.4 μg selenomethionine/g food (dry mass). Selenium accumulated in muscle and liver tissue in a dose-dependent manner. Edema causing exophthalmos developed within 15 d and 23 d, and lethal effects occurred in 54% and 22% of fish in the high- and medium-dose groups, respectively. Growth and hepatosomatic index were significantly lower in the high-dose group, which also had a high incidence of food avoidance. Histology of the liver revealed a dose-dependent increase in melanomacrophage aggregates and decrease of energy stores, which indicated toxicity. These results indicate that white sturgeon are susceptible to the effects of Se accumulation over relatively short time periods. This stresses the need for continued sturgeon research and studies looking into the environmental fate and regulation of released Se. Environ Toxicol Chem 2016;35:1741-1750. © 2015 SETAC. PMID:26632643

  14. Effects of Columbia River water on early life-stages of white sturgeon (Acipenser transmontanus).

    PubMed

    Tompsett, Amber R; Vardy, David W; Higley, Eric; Doering, Jon A; Allan, Marcie; Liber, Karsten; Giesy, John P; Hecker, Markus

    2014-03-01

    The white sturgeon (Acipenser transmontanus) population that resides in the Columbia River in British Columbia (BC), Canada, has suffered recruitment failures for more than three decades. During the summers of 2008 and 2009, studies were performed to determine whether exposure to water downstream of a metal smelter in Trail, BC affected survival or growth of early life-stages of white sturgeon through 60+ days post-fertilization (dpf). In both years, there were no significant differences in survival of fish that were exposed to water from downstream compared to water from upstream of the smelter. At 20-21dpf, average mortality was 2.4 percent and 12 percent in upstream water for 2008 and 2009, respectively, which was similar to the average mortality of 3.8 percent and 7.2 percent in downstream water for 2008 and 2009, respectively. Relatively great mortality after 20-21dpf complicated analysis of the subchronic exposure, but use of a survival analysis indicated that the average fish died at 25-29dpf, regardless of whether the water to which they were exposed came from upstream or downstream of the smelter. In addition, measured concentrations of metals in river water were less than the threshold for adverse effects on early life stages of white sturgeon. Based upon these analyses, it is not likely that current concentrations of metals in the Columbia River in southern BC are adversely affecting survival of early life stages of white sturgeon larvae. PMID:24507122

  15. [Antimutagenic activity of serotoninergic system and its mechanisms in Acipenser gueldenstaedti persicus and Carassius auratus].

    PubMed

    Mekhtiev, A A; Movsum-zade, S K

    2008-01-01

    The paper deals with antimutagenic body activity and its underlying mechanisms. The experiments carried out on the one-year old sturgeons (Acipenser gueldenstaedti persicus) and goldfish (Carassius auratus) have shown that intramuscular administration of serotoninmodulated anticonsolidation protein (SMAP) leads to a twofold decrease of erythrocyte mutagenic alterations (the micronuclear test, p < 0.01) caused by action of benthic deposits (0.8 ml/l, 3 days) polluted with industrial wastes. Exposure of goldfish in water contaminated with oil (500 mg/l, 3 days) led to a sharp rise of the content of the 70 kDa brain protein fraction (p < 0.001); these water-soluble proteins are assumed to belong to heat shock proteins (HSP). At the same time, in the brain of the studied animals there was observed a simultaneous increase of the SMAP content (p < 0.001). After 3 h, intracerebral SMAP administration to goldfish increased significantly the 90 kDa protein fraction content (p < 0.01), probably HSP90, in the electrophoretic profiles of the brain water-soluble proteins. Thus, the obtained results indicate that the body serotoninergic system has the antimutagenic activity providing protection of cells from action of harmful environmental factors by an enhancement of synthesis of proteins suggested to belong to HSP. PMID:18959209

  16. Comparison of fin ray sampling methods on white sturgeon Acipenser transmontanus growth and swimming performance.

    PubMed

    Nguyen, P L; Jackson, Z J; Peterson, D L

    2016-02-01

    Effects of two fin-ray sampling methods on swimming performance, growth and survival were evaluated for hatchery-reared sub-adult white sturgeon Acipenser transmontanus. Fish were subjected to either a notch removal treatment in which a small section was removed from an anterior marginal pectoral-fin ray, or a full removal treatment in which an entire marginal pectoral-fin ray was removed. Control fish did not have fin rays removed, but they were subjected to a sham operation. A modified 3230 l Brett-type swim tunnel was used to evaluate 10 min critical station-holding speeds (SCSH ) of A. transmontanus, immediately after the fin ray biopsies were obtained with each method. Survival and growth were evaluated over a 6 month period for a separate group of fish subjected to the same biopsy methods. Mean ± S.E. 10 min SCSH were 108·0 ± 2·3, 110·0 ± 2·6 and 115·0 ± 3·5 cm s(-1) for the notch removal group, full removal group and control group, respectively, and were not significantly different among treatments. Behavioural characteristics including tail-beat frequency and time spent hunkering were also not significantly different among treatment groups swimming at the same speeds. There were no mortalities and relative growth was similar among treatment groups. Average biopsy time for the notch removal method was lower and the wounds appeared to heal more quickly compared with the full removal method. PMID:26707821

  17. Genetic and demographic implications of aquaculture in white sturgeon (Acipenser transmontanus)conservation

    SciTech Connect

    Jager, Yetta

    2005-01-01

    This study uses a genetic individual-based model of white sturgeon (Acipenser transmontanus) populations in a river to examine the genetic and demographic trade-offs associated with operating a conservation hatchery. Simulation experiments evaluated three management practices: (i) setting quotas to equalize family contributions in an effort to prevent genetic swamping, (ii) an adaptive management scheme that interrupts stocking when introgression exceeds a specified threshold, and (iii) alternative broodstock selection strategies that influence domestication. The first set of simulations, designed to evaluate equalizing the genetic contribution of families, did not show the genetic benefits expected. The second set of simulations showed that simulated adaptive management was not successful in controlling introgression over the long term, especially with uncertain feedback. The third set of simulations compared the effects of three alternative broodstock selection strategies on domestication for hypothetical traits controlling early density-dependent survival. Simulated aquaculture selected for a density-tolerant phenotype when broodstock were taken from a genetically connected population. Using broodstock from an isolated population (i.e., above an upstream barrier or in a different watershed) was more effective at preventing domestication than using wild broodstock from a connected population.

  18. Changes in growth and osmoregulation during acclimation to saltwater in juvenile Amur sturgeon Acipenser schrenckii

    NASA Astrophysics Data System (ADS)

    Zhao, Feng; Zhuang, Ping; Zhang, Longzhen; Hou, Junli

    2010-05-01

    We evaluated the ability of juvenile Amur sturgeon ( Acipenser schrenckii) to osmoregulate and grow in saltwater. Hatchery-reared juveniles (mean weight 106.8 g, 5-month old) were transferred from freshwater to 10, 20, and 25 salinity saltwater over a period of 20 d. We measured the growth, serum osmolality, ion concentrations, and Na+/K+-ATPase activity. In addition, we prepared samples of gill tissue to quantify morphological changes in gill ultrastructure. Rearing in up to 25 saltwater for 30 d had no significant effect on growth. Similarly, serum osmolality and ion concentrations were similar to levels reported in other teleosts following acclimation to saltwater. Serum osmolality and Na+, Cl- concentrations increased significantly with the initial increase in salinity. Afterwards, levels tended to stabilize and then decrease. Serum K+ levels did not change during acclimation to saltwater. Gill Na+/K+-ATPase activity increased initially as salinity was increased. However, the activity later decreased and, finally stabilized at 3.7±0.1 μmol Pi/mg·prot·h in 25 saltwater (1.6 times higher than the level in those in freshwater). In fish that were held only in freshwater, the chloride cells were located in the interlamellar regions of the filament and at the base of the lamella. Following acclimation to 25 saltwater for 30 d, the number and size of chloride cells increased significantly. Our results suggest that juvenile Amur sturgeon is able to tolerate, and grow in, relatively high concentrations of saltwater.

  19. Cryopreservation of Persian sturgeon (Acipenser persicus) embryos by DMSO-based vitrificant solutions.

    PubMed

    Keivanloo, Saeide; Sudagar, Mohammad

    2016-03-15

    Vitrification could provide a promising tool for the cryopreservation of fish embryos. To achieve successful cryopreservation, several parameters should be taken into account in the design of a vitrification protocol. In the present study, some relevant factors were investigated (choice of a proper vitrificant solutions and temperature for thawing) using neurulation-stage embryos. Six DMSO-based vitrificant solutions (V1-V6) were tested using a 6-step incorporation protocol. DMSO-based vitrificant solutions contained DMSO + permeable cryoprotectants + nonpermeable cryoprotectants. Embryos were immersed in vitrificant solutions for 7 minutes and directly plunged into liquid nitrogen. After vitrification (-196 °C for 10 minutes), the thawing was performed in a water bath at 0 or 20 °C and then embryos incubated until hatched. Our results demonstrated that some embryos vitrified in 5 of 6 vitrification solutions survived and hatched out, but none survived after vitrification in V2. The highest survival rate (45.45%) was observed in samples frozen with the best vitrificant solution (V6) and thawing combination (20 °C). These results establish that cryopreservation of Persian sturgeon (Acipenser persicus) embryos by DMSO-based vitrificant solutions is possible. PMID:26768541

  20. Phylogeography of the European sturgeon (Acipenser sturio): A critically endangered species.

    PubMed

    Chassaing, Olivier; Desse-Berset, Nathalie; Hänni, Catherine; Hughes, Sandrine; Berrebi, Patrick

    2016-01-01

    The European sturgeon (Acipenser sturio) was once a common species throughout Europe, but the sole remaining natural population presently inhabits the Gironde Estuary in France (Atlantic coast). The species was classified as 'Critically Endangered' in 1996, and the Gironde population is now on the verge of extinction. In this setting, and for the first time, we present the past phylogeographical features of this species throughout Europe along with an assessment of its former genetic diversity. This study was based on a molecular analysis (mtDNA CR sequencing) of 10 living specimens from the Gironde Estuary, 55 museum specimens that had been caught along 19th and 20th centuries, and 59 archaeological remains dating back to 260-5000years BP, from which mitochondrial DNA was extracted and amplified. Although discontinuous, the produced data provided a realistic image of the former structure of A. sturio in Europe. Reconstruction of the phylogenetic trees and haplotypes network led to the identification of several clades. The mitochondrial genetic diversity of this species was found to be much greater at the core (Iberian Peninsula, Mediterranean and Adriatic regions) than along the margins (Atlantic-Northern Europe, Black Sea) of its range. A series of hypotheses on the dates and causes of changes in the species' major structures are put forward on the basis of these data. Finally, competition with A. oxyrinchus, a sibling species whose presence in Northern Europe was recently reconsidered, is presented as a major factor in the evolution of this species. PMID:26424382

  1. Neuroendocrine control of spawning in amphibians and its practical applications.

    PubMed

    Vu, Maria; Trudeau, Vance L

    2016-08-01

    Across vertebrates, ovulation and sperm release are primarily triggered by the timed surge of luteinizing hormone (LH). These key reproductive events are governed by the action of several brain neuropeptides, pituitary hormones and gonadal steroids which operate to synchronize physiology with behaviour. In amphibians, it has long been recognized that the neuropeptide gonadotropin-releasing hormone (GnRH) has stimulatory effects to induce spawning. Extensive work in teleosts reveals an inhibitory role of dopamine in the GnRH-regulated release of LH. Preliminary evidence suggests that this may be a conserved function in amphibians. Emerging studies are proposing a growing list of modulators beyond GnRH that are involved in the control of spawning including prolactin, kisspeptins, pituitary adenylate cyclase-activating polypeptide, gonadotropin-inhibitory hormone and endocannabinoids. Based on these physiological data, spawning induction methods have been developed to test on selective amphibian species. However, several limitations remain to be investigated to strengthen the evidence for future applications. The current state of knowledge regarding the neuroendocrine control of spawning in amphibians will be reviewed in detail, the elements of which will have wide implications towards the captive breeding of endangered amphibian species for conservation. PMID:27013378

  2. SPAWNING SUCCESS OF FATHEAD MINNOWS ON SELECTED ARTIFICIAL SUBSTRATES

    EPA Science Inventory

    Spawning success of fathead minnows (Pimephales promelas) on six different substrates was tested and evaluated. Egg adhesiveness was equally good on cement-asbestos tile and sand-coated stainless steel substrates, but was poor on unaltered stainless steel, shot-peened stainless s...

  3. Gauging the Reproductive Potential of Salmon Spawning Substrates

    NASA Astrophysics Data System (ADS)

    Overstreet, B. T.; Riebe, C. S.; Wooster, J. K.

    2011-12-01

    Millions of dollars are spent annually on revitalizing salmon spawning habitat in rivers where bed-surface sediment is too large for female fish to move as they try to build redds. Yet the conditions necessary for productive spawning remain unclear; there is no method for interpreting grain size in terms of a substrate's capacity for accommodating redds. Hence, river managers lack a quantitative basis for optimizing restoration expenditures and monitoring their effectiveness over time. Here we elaborate on a recently developed model that predicts a substrate's areal density of spawning redds as a continuous function of grain size from measurements of fish length and the grain size indices D50 and D84. Exploration of the model's parameter space reveals previously unrecognized tradeoffs in how a substrate's egg-carrying capacity varies with fish size due to differences in area required per redd, coverage by movable particles, and fecundity. The model indicates that the number of redds a substrate can accommodate is maximized at an intermediate fish length, reflecting a balance between the size of salmon redds and the fraction of the bed that female fish are able to move during redd building. We illustrate how the model can be used to gauge the reproductive potential of spawning substrates and optimize the effectiveness of sediment augmentation in coarse-bedded rivers.

  4. Coral mass spawning predicted by rapid seasonal rise in ocean temperature.

    PubMed

    Keith, Sally A; Maynard, Jeffrey A; Edwards, Alasdair J; Guest, James R; Bauman, Andrew G; van Hooidonk, Ruben; Heron, Scott F; Berumen, Michael L; Bouwmeester, Jessica; Piromvaragorn, Srisakul; Rahbek, Carsten; Baird, Andrew H

    2016-05-11

    Coral spawning times have been linked to multiple environmental factors; however, to what extent these factors act as generalized cues across multiple species and large spatial scales is unknown. We used a unique dataset of coral spawning from 34 reefs in the Indian and Pacific Oceans to test if month of spawning and peak spawning month in assemblages of Acropora spp. can be predicted by sea surface temperature (SST), photosynthetically available radiation, wind speed, current speed, rainfall or sunset time. Contrary to the classic view that high mean SST initiates coral spawning, we found rapid increases in SST to be the best predictor in both cases (month of spawning: R(2) = 0.73, peak: R(2) = 0.62). Our findings suggest that a rapid increase in SST provides the dominant proximate cue for coral mass spawning over large geographical scales. We hypothesize that coral spawning is ultimately timed to ensure optimal fertilization success. PMID:27170709

  5. Comparative transcriptome analysis of testes and ovaries for the discovery of novel genes from Amur sturgeon (Acipenser schrenckii).

    PubMed

    Jin, S B; Zhang, Y; Dong, X L; Xi, Q K; Song, D; Fu, H T; Sun, D J

    2015-01-01

    Sturgeons (Acipenser schrenckii) are of high evolutionary, economic, and conservation value, and caviar isone of the most valuable animal food products in the world. The Illumina HiSeq2000 sequencing platform was used to construct testicular and ovarian transcriptomes to identify genes involved in reproduction and sex determination in A. schrenckii. A total of 122,381 and 114,527 unigenes were obtained in the testicular and ovarian transcriptomes, respectively, with average lengths of 748 and 697 bp. A total of 46,179 genes were matched to the non-redundant nr database. GO (31,266), KEGG (39,712), and COG analyses (20,126) were performed to identify potential genes and their functions. Twenty-six gene families involved in reproduction and sex determination were identified from the A. schrenckii testicular and ovarian transcriptomes based on functional annotation of non-redundant transcripts and comparisons with the published literature. Furthermore, 1309 unigenes showed significant differences between the testes and ovaries, including 782 genes that were up-regulated in the testes and 527 that were up-regulated in the ovaries. Eleven genes were involved in reproduction and sex determination mechanisms. Furthermore, 19,065 simple sequence repeats (SSRs) were identified in the expressed sequence tagged dataset, and 190,863 and 193,258 single nucleotide polymorphisms (SNPs) were obtained from the testicular and ovarian transcriptomic databases, respectively. This study provides new sequence information about A. schrenckii, which will provide a basis for the further study of reproduction and sex determination mechanisms in Acipenser species. The potential SSR and SNP markers isolated from the transcriptome may shed light on the evolution and molecular ecology of Acipenser species. PMID:26782541

  6. Expression of dmrt1 and vtg genes during gonad formation, differentiation and early maturation in cultured Russian sturgeon Acipenser gueldenstaedtii.

    PubMed

    Fajkowska, M; Rzepkowska, M; Adamek, D; Ostaszewska, T; Szczepkowski, M

    2016-08-01

    Expression of the dmrt1 and vtg genes was described using the real-time PCR (rt-PCR) method from 25 to 1600 days post-hatch (dph) in cultured Russian sturgeon Acipenser gueldenstaedtii. The level of dmrt1 transcription in gonads in subsequent studied periods increased exponentially while vtg expression increased in gonads and livers of A. gueldenstaedtii examined, but in later stages of development. Both dmrt1 and vtg genes showed elevated expression in intersex individuals probably caused by dietary exposure to phyto-oestrogens. PMID:27239004

  7. Distribution, abundance, and spawning season and grounds of the kiyi, Leucichthys kiyi Koelz, in Lake Michigan

    USGS Publications Warehouse

    Hile, Ralph; Deason, Hilary J.

    1947-01-01

    The depth of water on known spawning grounds (all in southern Lake Michigan) was 57.5 to 84 fathoms. There is evidence that the kiyi may spawn in more than 90 fathoms. Spawning appears to be widespread throughout waters of suitable depth.

  8. A Computational Model for Asynchronous Oocyte Growth Dynamics in Spawning Fish

    EPA Science Inventory

    This manuscript describes the development of a computational model that simulates a time course of oocyte growth and spawning for asynchronous spawning fish, based upon plasma vitellogenin concentrations and a critical oocyte size for spawning. The model provides a framework that...

  9. Impact of Ichthyophonus infection on spawning success of Yukon River Chinook salmon Oncorhynchus tshawytscha.

    PubMed

    Hamazaki, Toshihide; Kahler, Eryn; Borba, Bonnie M; Burton, Tamara

    2013-11-01

    We examined the impacts of Ichthyophonus infection on spawning success of Yukon River Chinook salmon Oncorhynchus tshawytscha at spawning grounds of the Chena and Salcha Rivers, Alaska, USA. During the period 2005 to 2006, 1281 salmon carcasses (628 male, 652 female) were collected throughout the spawning season and from the entire spawning reaches of the Chena and Salcha Rivers. For each fish, infection status was determined by culture method and visual inspection of lesions of heart tissue as uninfected (culture negative), infected without lesions (culture positive with no visible lesions), and infected with lesions (culture positive with visible lesions), and spawning status was determined by visually inspecting the percentage of gametes remaining as full-spawned (<10%), partial-spawned (10-50%), and unspawned (>50%). Among the 3 groups, the proportion of full-spawned (i.e. spawning success) females was lower for those infected without lesions (69%) than those uninfected (87%) and infected with lesions (86%), but this did not apply to males (uninfected 42%, infected without lesions 38%, infected with lesions 41%). At the population level, the combined (infected and uninfected) proportion of female spawning success was 86%, compared to 87% when all females were assumed uninfected. These data suggest that while Ichthyophonus infection slightly reduces spawning success of infected females, its impact on the spawning population as a whole appears minimal. PMID:24191998

  10. Identifying spawning behavior in Pacific halibut (Hippoglossus stenolepis) using electronic tags

    USGS Publications Warehouse

    Seitz, A.C.; Norcross, B.L.; Wilson, D.; Nielsen, J.L.

    2005-01-01

    Identifying spawning behavior in Pacific halibut, Hippoglossus stenolepis, is particularly challenging because they occupy a deep, remote environment during the spawning season. To identify spawning events, a method is needed in which direct observation by humans is not employed. Spawning behavior of seven other flatfish, species has been directly observed in their natural environment by investigators using SCUBA. All of these flatfish species display almost identical spawning behavior that follows a routine. Therefore, it is reasonable to believe that this spawning behavior occurs in other flatfish species, including Pacific halibut. As part of a larger study, we recaptured two Pacific halibut on which Pop-up Archival Transmitting (PAT) tags had been attached during the winter spawning season. Because the tags were physically retrieved, we were able to collect minute-by-minute depth records for 135 and 155 days. We used these depth data to tentatively identify spawning events. On seven separate occasions between 20 January 2001 and 9 February 2001, one fish displayed a conspicuous routine only seen during the spawning season of Pacific halibut and the routine parallels the actions of other spawning flatfish directly observed by humans using SCUBA. Therefore, we propose this routine represents spawning behavior in Pacific halibut. The second tagged fish did not display the conspicuous routine, thus challenging the assumption that Pacific halibut are annual spawners. PAT tags may prove to be a useful tool for identifying spawning events of Pacific halibut, and that knowledge may be used for improved management in the future. 

  11. Effects of lake surface elevation on shoreline-spawning Lost River Suckers

    USGS Publications Warehouse

    Burdick, Summer M.; Hewitt, David A.; Rasmussen, J.E.; Hayes, Brian; Janney, Eric; Harris, Alta C.

    2015-01-01

    We analyzed remote detection data from PIT-tagged Lost River Suckers Deltistes luxatus at four shoreline spawning areas in Upper Klamath Lake, Oregon, to determine whether spawning of this endangered species was affected by low water levels. Our investigation was motivated by the observation that the surface elevation of the lake during the 2010 spawning season was the lowest in 38 years. Irrigation withdrawals in 2009 that were not replenished by subsequent winter-spring inflows caused a reduction in available shoreline spawning habitat in 2010. We compared metrics of skipped spawning, movement among spawning areas, and spawning duration across 8 years (2006-2013) that had contrasting spring water levels. Some aspects of sucker spawning were similar in all years, including few individuals straying from the shoreline areas to spawning locations in lake tributaries and consistent effects of increasing water temperatures on the accumulation of fish at the spawning areas. During the extreme low water year of 2010, 14% fewer female and 8% fewer male suckers joined the shoreline spawning aggregation than in the other years. Both males and females visited fewer spawning areas within Upper Klamath Lake in 2010 than in other years, and the median duration at spawning areas in 2010 was at least 36% shorter for females and 20% shorter for males relative to other years. Given the imperiled status of the species and the declining abundance of the population in Upper Klamath Lake, any reduction in spawning success and egg production could negatively impact recovery efforts. Our results indicate that lake surface elevations above 1,262.3-1,262.5 m would be unlikely to limit the number of spawning fish and overall egg production.

  12. Spawning Site Selection and Contingent Behavior in Common Snook, Centropomus undecimalis

    PubMed Central

    Lowerre-Barbieri, Susan; Villegas-Ríos, David; Walters, Sarah; Bickford, Joel; Cooper, Wade; Muller, Robert; Trotter, Alexis

    2014-01-01

    Reproductive behavior affects spatial population structure and our ability to manage for sustainability in marine and diadromous fishes. In this study, we used fishery independent capture-based sampling to evaluate where Common Snook occurred in Tampa Bay and if it changed with spawning season, and passive acoustic telemetry to assess fine scale behavior at an inlet spawning site (2007–2009). Snook concentrated in three areas during the spawning season only one of which fell within the expected spawning habitat. Although in lower numbers, they remained in these areas throughout the winter months. Acoustically-tagged snook (n = 31) showed two seasonal patterns at the spawning site: Most fish occurred during the spawning season but several fish displayed more extended residency, supporting the capture-based findings that Common Snook exhibit facultative catadromy. Spawning site selection for iteroparous, multiple-batch spawning fishes occurs at the lifetime, annual, or intra-annual temporal scales. In this study we show colonization of a new spawning site, indicating that lifetime spawning site fidelity of Common Snook is not fixed at this fine spatial scale. However, individuals did exhibit annual and intra-seasonal spawning site fidelity to this new site over the three years studied. The number of fish at the spawning site increased in June and July (peak spawning months) and on new and full lunar phases indicating within population variability in spawning and movement patterns. Intra-seasonal patterns of detection also differed significantly with sex. Common Snook exhibited divergent migration tactics and habitat use at the annual and estuarine scales, with contingents using different overwintering habitat. Migration tactics also varied at the spawning site at the intra-seasonal scale and with sex. These results have important implications for understanding how reproductive behavior affects spatio-temporal patterns of fish abundance and their resilience to

  13. Spawning Dynamics and Size Related Trends in Reproductive Parameters of Southern Bluefin Tuna, Thunnus maccoyii

    PubMed Central

    Farley, Jessica. H.; Davis, Tim L. O.; Bravington, Mark V.; Andamari, Retno; Davies, Campbell R.

    2015-01-01

    Knowledge of spawning behaviour and fecundity of fish is important for estimating the reproductive potential of a stock and for constructing appropriate statistical models for assessing sustainable catch levels. Estimates of length-based reproductive parameters are particularly important for determining potential annual fecundity as a function of fish size, but they are often difficult to estimate reliably. Here we provide new information on the reproductive dynamics of southern bluefin tuna (SBT) Thunnus maccoyii through the analysis of fish size and ovary histology collected on the spawning ground in 1993–1995 and 1999–2002. These are used to refine previous parameter estimates of spawning dynamics and investigate size related trends in these parameters. Our results suggest that the small SBT tend to arrive on the spawning ground slightly later and depart earlier in the spawning season relative to large fish. All females were mature and the majority were classed as spawning capable (actively spawning or non-spawning) with a very small proportion classed as regressing. The fraction of females spawning per day decreased with fish size, but once females start a spawning episode, they spawned daily irrespective of size. Mean batch fecundity was estimated directly at 6.5 million oocytes. Analysis of ovary histology and ovary weight data indicated that relative batch fecundity, and the duration of spawning and non-spawning episodes, increased with fish size. These reproductive parameter estimates could be used with estimates of residency time on the spawning ground as a function of fish size (if known) and demographic data for the spawning population to provide a time series of relative annual fecundity for SBT. PMID:25993276

  14. Spawning site selection and contingent behavior in Common Snook, Centropomus undecimalis.

    PubMed

    Lowerre-Barbieri, Susan; Villegas-Ríos, David; Walters, Sarah; Bickford, Joel; Cooper, Wade; Muller, Robert; Trotter, Alexis

    2014-01-01

    Reproductive behavior affects spatial population structure and our ability to manage for sustainability in marine and diadromous fishes. In this study, we used fishery independent capture-based sampling to evaluate where Common Snook occurred in Tampa Bay and if it changed with spawning season, and passive acoustic telemetry to assess fine scale behavior at an inlet spawning site (2007-2009). Snook concentrated in three areas during the spawning season only one of which fell within the expected spawning habitat. Although in lower numbers, they remained in these areas throughout the winter months. Acoustically-tagged snook (n = 31) showed two seasonal patterns at the spawning site: Most fish occurred during the spawning season but several fish displayed more extended residency, supporting the capture-based findings that Common Snook exhibit facultative catadromy. Spawning site selection for iteroparous, multiple-batch spawning fishes occurs at the lifetime, annual, or intra-annual temporal scales. In this study we show colonization of a new spawning site, indicating that lifetime spawning site fidelity of Common Snook is not fixed at this fine spatial scale. However, individuals did exhibit annual and intra-seasonal spawning site fidelity to this new site over the three years studied. The number of fish at the spawning site increased in June and July (peak spawning months) and on new and full lunar phases indicating within population variability in spawning and movement patterns. Intra-seasonal patterns of detection also differed significantly with sex. Common Snook exhibited divergent migration tactics and habitat use at the annual and estuarine scales, with contingents using different overwintering habitat. Migration tactics also varied at the spawning site at the intra-seasonal scale and with sex. These results have important implications for understanding how reproductive behavior affects spatio-temporal patterns of fish abundance and their resilience to

  15. Suspended spawning cans for channel catfish in a surface-mine lake. [Ictalurus punctatus

    SciTech Connect

    Moy, P.B.; Stickney, R.R.

    1987-01-01

    A technique was developed to enable channel catfish (Ictalurus punctatus) to spawn in lakes where sufficient spawning habitat is not available. Forty-five-liter spawning cans were suspended from styrofoam floats at a depth of 1.25 m below the water surface, in water that was 2-5 m deep. Brood fish successfully utilized the containers for spawning, and the presence of eggs in sunken containers suggests that channel catfish will spawn successfully at depths of up to 5 m if satisfactory nesting sites are available.

  16. White sturgeon (Acipenser transmontanus) passage at the Dalles Dam, Columbia River, USA

    USGS Publications Warehouse

    Parsley, M.J.; Wright, C.D.; Van Der Leeuw, B. K.; Kofoot, E.E.; Peery, C.A.; Moser, M.L.

    2007-01-01

    White sturgeon (Acipenser transmontanus) ???95 cm TL were monitored using acoustic and radio telemetry at a large hydroelectric dam (the Dalles Dam) on the Columbia River, during March 2004 through November 2005 to determine timing and routes of passage and to characterize general movements. Transmitters were surgically implanted into 148 fish during the study; 90 were released into the tailrace and 58 into the forebay. We documented 26 passage events by 19 tagged fish: eight upstream via fish ladders and 18 downstream, mostly through open spill gates. During the study 17 fish entered the two ladders one or more times; 11 entered only the east ladder, three entered only the north ladder, and three entered both ladders at sometime. Residence time within the ladders by individual fish was variable, ranging from about 1 min to nearly 6 months (median = 7.7 h). Only six fish successfully ascended the east ladder, one fish twice. We could not unequivocally determine which fish ladder one fish used to pass upstream. Differences in construction between the north and east fish ladders may account for the greater success of the east fish ladder in passing sturgeon upstream. Changes to operations at hydroelectric dams to benefit migrating anadromous salmonids may influence upstream or downstream passage by white sturgeon. Altering patterns and timing of spill discharge, altering fish ladder entrance attraction flows, and the use of lights, sound, and partial barriers to direct other species of fish to preferred passage routes have unknown effects on sturgeon passage. A better understanding of the consequences to the metapopulation of increasing or precluding upstream or downstream passage is needed. ?? 2007 The Authors.

  17. Stress and its relation to endocrine function in captive female Siberian sturgeon (Acipenser baeri).

    PubMed

    Hamlin, Heather J; Edwards, Thea M; Moore, Brandon C; Main, Kevan L; Guillette, Louis J

    2007-01-01

    Stress responses to numerous environmental conditions have been studied in a wide range of fish species. Defining the relationship between stress and endocrine function is particularly critical to long-lived species such as sturgeons, whose economic viability relies heavily on proper endocrine function for the production of caviar. In this study, we examined the induced stress response, defined by plasma cortisol and glucose concentrations, and its relationship to plasma 17beta-estradiol, testosterone and 11-ketotestosterone concentrations in cultured female Siberian sturgeon (Acipenser baeri). Fish were acutely stressed using capture and confinement for a period of 4 h, and blood samples were drawn according to four treatment regimens: treatment 1, fish were bled at 0 h; treatment 2, fish were serially bled at 0 h, 1 h and 4 h; treatment 3, fish were bled at 1 h and 4 h; treatment 4, fish were bled at 4 h only. Fish were surgically sexed immediately after drawing blood at 0 h. After 1 h of acute stress, fish demonstrated a marked increase in plasma cortisol concentration, which remained elevated throughout the 4-h sampling period. The plasma concentration of sex steroids did not exhibit an inverse relationship with plasma cortisol concentration. Plasma testosterone concentration was significantly elevated during the periods of greatest stress. Plasma estradiol and 11-ketotestosterone (11-KT) concentrations were not affected by the acute stressors in this experiment. Serial bleedings, however, affected the associated stress response, which is an important consideration for future studies with this species. This is the first study to define the relationship between stress and possible changes in sex steroid concentration in this threatened and commercially important species. PMID:17622217

  18. Functional C1q is present in the skin mucus of Siberian sturgeon (Acipenser baerii).

    PubMed

    Fan, Chunxin; Wang, Jian; Zhang, Xuguang; Song, Jiakun

    2015-01-01

    The skin mucus of fish acts as the first line of self-protection against pathogens in the aquatic environment and comprises a number of innate immune components. However, the presence of the critical classical complement component C1q, which links the innate and adaptive immune systems of mammalians, has not been explored in a primitive actinopterygian fish. In this study, we report that C1q is present in the skin mucus of the Siberian sturgeon (Acipenser baerii). The skin mucus was able to inhibit the growth of Escherichia coli. The bacteriostatic activity of the skin mucus was reduced by heating and by pre-incubation with EDTA or mouse anti-human C1q antibody. We also detected C1q protein in skin mucus using the western blot procedure and isolated a cDNA that encodes the Siberian sturgeon C1qC, which had 44.7-51.4% identity with C1qCs in teleosts and tetrapods. A phylogenetic analysis revealed that Siberian sturgeon C1qC lies at the root of the actinopterygian branch and is separate from the tetrapod branch. The C1qC transcript was expressed in many tissues as well as in skin. Our data indicate that C1q is present in the skin mucus of the Siberian sturgeon to protect against water-borne bacteria, and the C1qC found in the sturgeon may represent the primitive form of teleost and tetrapod C1qCs. PMID:24920077

  19. Effect of nutritional status on the osmoregulation of green sturgeon (Acipenser medirostris).

    PubMed

    Haller, Liran Y; Hung, Silas S O; Lee, Seunghyung; Fadel, James G; Lee, Jun-Ho; McEnroe, Maryann; Fangue, Nann A

    2015-01-01

    Anthropogenic climate change is linked to food web and salinity fluctuations in estuarine environments. Both decreased nutritional status and environmental salinity influence the physiological tolerance and health of fish populations; however, limited information on the interaction of these two factors and their physiological consequences is available. The green sturgeon (Acipenser medirostris) is a species of special concern in California, and the southern distinct population segment is listed as threatened. To test the hypothesis that poor nutrition negatively affects osmoregulation, juvenile green sturgeon (222 d posthatch) were randomly assigned to four feed restriction groups (12.5%, 25%, 50%, and 100% of the optimal feeding rate for 4 wk). Fish were then acutely exposed to 0-, 8-, 16-, or 32-ppt salinities and sampled at three time points (12, 72, or 120 h). Feed restriction significantly (P < 0.05) decreased specific growth rate, feed efficiency, condition factor, whole-body lipids, and protein content as well as plasma glucose, triglycerides, and proteins. Furthermore, feed restriction, salinity concentration, and salinity exposure time had significant effects on hematological indexes (hematocrit, hemoglobin), plasma values (osmolality, Na(+), K(+), Cl(-), glucose, lactate, cortisol), enzymatic activity (gill and pyloric ceca Na(+)/K(+) ATPase), and morphology of gill mitochondria-rich cells. The largest disturbances were observed at the highest salinity treatments across all feeding regimes. In addition, the interaction between feed restriction and acute salinity exposure at the highest salinity treatment resulted in high mortality rates during the first 72 h of salinity exposure. Evaluating the interactions of these environmental stressors and their implications on green sturgeon physiological tolerance will inform restoration and management efforts in rapidly changing estuarine environments. PMID:25590591

  20. Transcriptome analysis and de novo annotation of the critically endangered Amur sturgeon (Acipenser schrenckii).

    PubMed

    Zhang, X J; Jiang, H Y; Li, L M; Yuan, L H; Chen, J P

    2016-01-01

    The aim of this study was to provide comprehensive insights into the genetic background of sturgeon by transcriptome study. We performed a de novo assembly of the Amur sturgeon Acipenser schrenckii transcriptome using Illumina Hiseq 2000 sequencing. A total of 148,817 non-redundant unigenes with base length of approximately 121,698,536 bp and ranges from 201 to 26,789 bp were obtained. All the unigenes were classified into 3368 distinct categories and 145,449 singletons by homologous transcript cluster analysis. In all, 46,865 (31.49%) unigenes showed homologous matches with Nr database and 32,214 (21.65%) unigenes were matched to Nt database. In total, 24,862 unigenes were categorized into significantly enriched 52 function groups by GO analysis, and 38,436 unigenes were classified into 25 groups by KOG prediction, as well as 128 enriched KEGG pathways were identified by 45,598 unigenes (P < 0.05). Subsequently, a total of 19,860 SSRs markers were identified with the abundant di-nucleotide type (10,658; 53.67%) and the most AT/TA motif repeats (2689; 13.54%). A total of 1341 conserved lncRNAs were identified by a customized pipeline. Our study provides new sequence and function information for A. schrenckii, which will be the basis for further genetic studies on sturgeon species. The huge number of potential SSRs and putatively conserved lncRNAs isolated by the transcriptome also shed light on research in many fields, including the evolution, conservation management, and biological processes in sturgeon. PMID:27420941

  1. Sequencing and De Novo Assembly of the Gonadal Transcriptome of the Endangered Chinese Sturgeon (Acipenser sinensis)

    PubMed Central

    Du, Hao; Zhang, Shuhuan; Wei, Qiwei

    2015-01-01

    Background The Chinese sturgeon (Acipenser sinensis) is endangered through anthropogenic activities including over-fishing, damming, shipping, and pollution. Controlled reproduction has been adopted and successfully conducted for conservation. However, little information is available on the reproductive regulation of the species. In this study, we conducted de novo transcriptome assembly of the gonad tissue to create a comprehensive dataset for A. sinensis. Results The Illumina sequencing platform was adopted to obtain 47,333,701 and 47,229,705 high quality reads from testis and ovary cDNA libraries generated from three-year-old A. sinensis. We identified 86,027 unigenes of which 30,268 were annotated in the NCBI non-redundant protein database and 28,281 were annotated in the Swiss-prot database. Among the annotated unigenes, 26,152 and 7,734 unigenes, respectively, were assigned to gene ontology categories and clusters of orthologous groups. In addition, 12,557 unigenes were mapped to 231 pathways in the Kyoto Encyclopedia of Genes and Genomes Pathway database. A total of 1,896 unigenes, potentially differentially expressed between the two gonad types, were found, with 1,894 predicted to be up-regulated in ovary and only two in testis. Fifty-five potential gametogenesis-related genes were screened in the transcriptome and 34 genes with significant matches were found. Besides, more paralogs of 11 genes in three gene families (sox, apolipoprotein and cyclin) were found in A. sinensis compared to their orthologs in the diploid Danio rerio. In addition, 12,151 putative simple sequence repeats (SSRs) were detected. Conclusions This study provides the first de novo transcriptome analysis currently available for A. sinensis. The transcriptomic data represents the fundamental resource for future research on the mechanism of early gametogenesis in sturgeons. The SSRs identified in this work will be valuable for assessment of genetic diversity of wild fish and genealogy

  2. Effect of freezing rate for cryopreservation of Persian sturgeon (Acipenser persicus) spermatozoa.

    PubMed

    Aramli, Mohammad Sadegh; Golshahi, Karim; Nazari, Rajab Mohammad; Sotoudeh, Ebrahim; Aramli, Salim; Habibi, Ensieh

    2016-03-01

    This study examined the effect of freezing rate (-10 °C, -15 °C, -20 °C, -30 °C, and -40 °C/min) on motility parameters, rates of fertilization and hatching, ATP content, and indices of oxidative stress including thiobarbituric acid reactive substances and carbonyl derivatives of proteins in Persian sturgeon (Acipenser persicus) sperm. After sampling, sperm was diluted in an extender composed of 23.4-mM sucrose, 0.25-mM KCl, and 30-mM Tris-HCl, pH 8.0, containing 10% methanol and subsequently frozen in a programmable freezer. For postthaw sperm that were frozen at a rate of -40 °C/min, sperm motile duration (134 ± 27.01 seconds), sperm motile percent (60 ± 4.1%), fertilizability (72 ± 8.36% for fertilization rate and 65 ± 7.58% for hatching rate), and ATP content (4.8 ± 0.57 nmol/10(8) sperm) were significantly higher than for sperm frozen at any of the four slower rates (P < 0.05). Moreover, sperm cryopreserved using the fastest freezing rate had significantly lower levels of thiobarbituric acid reactive substances (0.5 ± 0.05 nmol/10(8) sperm) and carbonyl derivatives of proteins (41.3 ± 4.9 nmol/10(8) sperm) than sperm cryopreserved using all other freezing rates (P < 0.05). In addition, there is a significant difference (P < 0.05) between fresh sperm and the recovery of cryopreserved Persian sturgeon sperm using programmable freezing with -40 °C/min being the optimal freezing rate among those tested. PMID:26549121

  3. Exposure of Persian sturgeon (Acipenser persicus) to cadmium results in biochemical, histological and transcriptional alterations.

    PubMed

    Miandare, Hamed Kolangi; Niknejad, Mahtab; Shabani, Ali; Safari, Roghieh

    2016-01-01

    Sturgeon is one of the endangered families of fish in the Caspian Sea region, where there is up to 80% of their global caching. Unfortunately, in recent years, increase of pollutants has been resulted in their total population reduction. Due to their benthic nature, sturgeons are at great risk of exposing to contaminants such as cadmium. Despite their endangered status in the Caspian Sea, there are only a few studies on characterizing the relative sensitivity of sturgeons to cadmium. Adverse effects associated with pollution on angiogenesis are mediated by hypoxia inducing factor-1 (HIF-1) and vascular endothelial growth factor (VEGF). In this investigation, gene expression of two distinct HIFs-1, HIF-1α and HIF-2α, and VEGF was investigated at the mRNA transcript levels after exposure of Persian sturgeon (Acipenser persicus) to cadmium. VEGF, HIF-1α and HIF-2α expressions in treated Persian sturgeon were greater than controls. Significant increases (P<0.05) were also observed in cortisol and glucose levels compared to the control group especially in the fish exposed to higher cadmium concentration (800 μg/L). Plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactic acid dehydrogenase (LDH) levels were increased in the cadmium-exposed fish, although the observed increases were not significant between the control and 200 μg/L cadmium treatment at some sampling time points. Gill tissues also showed histopathological changes in the cadmium treatments. Overall, results indicated that cadmium resulted in some alterations in biochemical parameters, mRNA transcript level expression of two important angiogenesis related genes as well as histological alterations in Persian sturgeon. PMID:26687766

  4. Modeling the spawning strategies and larval survival of the Brazilian sardine (Sardinella brasiliensis)

    NASA Astrophysics Data System (ADS)

    Dias, Daniela Faggiani; Pezzi, Luciano Ponzi; Gherardi, Douglas Francisco Marcolino; Camargo, Ricardo

    2014-04-01

    An Individual Based Model (IBM), coupled with a hydrodynamic model (ROMS), was used to investigate the spawning strategies and larval survival of the Brazilian Sardine in the South Brazil Bight (SBB). ROMS solutions were compared with satellite and field data to assess their representation of the physical environment. Two spawning experiments were performed for the summer along six years, coincident with ichthyoplankton survey cruises. In the first one, eggs were released in spawning habitats inferred from a spatial model. The second experiment simulated a random spawning to test the null hypothesis that there are no preferred spawning sites. Releasing eggs in the predefined spawning habitats increases larval survival, suggesting that the central-southern part of the SBB is more suitable for larvae development because of its thermodynamic characteristics. The Brazilian sardine is also capable of exploring suitable areas for spawning, according to the interannual variability of the SBB. The influence of water temperature, the presence of Cape Frio upwelling, and surface circulation on the spawning process was tested. The Cape Frio upwelling plays an important role in the modulation of Brazilian sardine spawning zones over SBB because of its lower than average water temperature. This has a direct influence on larval survival and on the interannual variability of the Brazilian sardine spawning process. The hydrodynamic condition is crucial in determining the central-southern part of SBB as the most suitable place for spawning because it enhances simulated coastal retention of larvae.

  5. Spawning phenology and geography of Aleutian Islands and eastern Bering Sea Pacific cod (Gadus macrocephalus)

    NASA Astrophysics Data System (ADS)

    Neidetcher, Sandra K.; Hurst, Thomas P.; Ciannelli, Lorenzo; Logerwell, Elizabeth A.

    2014-11-01

    Pacific cod (Gadus macrocephalus) is an economically and ecologically important species in the southeastern Bering Sea and Aleutian Islands, yet little is known about the spawning dynamics of Pacific cod in these regions. To address this knowledge gap, we applied a gross anatomical maturity key for Pacific cod to describe temporal and spatial patterns of reproductive status over three winter spawning seasons: 2005, 2006, and 2007. Maturity status of female Pacific cod was assessed by fishery observers during sampling of commercial catches and used to construct maps showing spawning activity in the Bering Sea and Aleutian Islands. Most spawning activity was observed on the Bering Sea shelf and Aleutian Island plateaus between 100 and 200 m depth. Data for those days when a high percentage of spawning stage fish were observed were used to identify areas with concentrations of spawning fish. Spawning concentrations were identified north of Unimak Island, in the vicinity of the Pribilof Islands, at the shelf break near Zhemchug Canyon, and adjacent to islands in the central and western Aleutian Islands along the continental shelf. The spawning season was found to begin in the last days of February or early March and extend through early to mid-April. Variation in spawning time (averaging ~10 days between years) may have been associated with a change from warm (2005) to cold (2007) climate conditions during the study period. Our information on Pacific cod spawning patterns will help inform fishery management decisions, models of spawning and larval dispersal and the spatial structure of the stock.

  6. Transcriptome Sequencing, De Novo Assembly and Differential Gene Expression Analysis of the Early Development of Acipenser baeri

    PubMed Central

    Song, Wei; Jiang, Keji; Zhang, Fengying; Lin, Yu; Ma, Lingbo

    2015-01-01

    The molecular mechanisms that drive the development of the endangered fossil fish species Acipenser baeri are difficult to study due to the lack of genomic data. Recent advances in sequencing technologies and the reducing cost of sequencing offer exclusive opportunities for exploring important molecular mechanisms underlying specific biological processes. This manuscript describes the large scale sequencing and analyses of mRNA from Acipenser baeri collected at five development time points using the Illumina Hiseq2000 platform. The sequencing reads were de novo assembled and clustered into 278167 unigenes, of which 57346 (20.62%) had 45837 known homologues proteins in Uniprot protein databases while 11509 proteins matched with at least one sequence of assembled unigenes. The remaining 79.38% of unigenes could stand for non-coding unigenes or unigenes specific to A. baeri. A number of 43062 unigenes were annotated into functional categories via Gene Ontology (GO) annotation whereas 29526 unigenes were associated with 329 pathways by mapping to KEGG database. Subsequently, 3479 differentially expressed genes were scanned within developmental stages and clustered into 50 gene expression profiles. Genes preferentially expressed at each stage were also identified. Through GO and KEGG pathway enrichment analysis, relevant physiological variations during the early development of A. baeri could be better cognized. Accordingly, the present study gives insights into the transcriptome profile of the early development of A. baeri, and the information contained in this large scale transcriptome will provide substantial references for A. baeri developmental biology and promote its aquaculture research. PMID:26359664

  7. Does small-bodied salmon spawning activity enhance streambed mobility?

    NASA Astrophysics Data System (ADS)

    Hassan, Marwan A.; Tonina, Daniele; Buxton, Todd H.

    2015-09-01

    Female salmonids bury and lay their eggs in streambeds by digging a pit, which is then covered with sediment from a second pit that is dug immediately upstream. The spawning process alters streambed topography, winnows fine sediment, and mixes sediment in the active layer. The resulting egg nests (redds) contain coarser and looser sediments than those of unspawned streambed areas, and display a dune-like shape with an amplitude and length that vary with fish size, substrate conditions, and flow conditions. Redds increase local bed surface roughness (<10-1 channel width, W), but may reduce the size of macro bedforms by eroding reach-scale topography (100-101W). Research has suggested that spawning may increase flow resistance due to redd form drag, resulting in lower grain shear stress and less particle mobility. Spawning, also prevents streambed armoring by mixing surface and subsurface material, potentially increasing particle mobility. Here we use two-dimensional hydraulic modeling with detailed prespawning and postspawning bathymetries and field observations to test the effect of spawning by small-bodied salmonids on sediment transport. Our results show that topographical roughness from small salmon redds has negligible effects on shear stress at the reach-unit scale, and limited effects at the local scale. Conversely, results indicate sediment mixing reduces armoring and enhances sediment mobility, which increases potential bed load transport by subsequent floods. River restoration in fish-bearing streams should take into consideration the effects of redd excavation on channel stability. This is particularly important for streams that historically supported salmonids and are the focus of habitat restoration actions.

  8. Pump for spawning channels includes a turbine and motor. Turbine ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Pump for spawning channels includes a turbine and motor. Turbine is Berkeley H-17500, model 8C2PH, Serial No. 2889, B.M. No. 4886 - Berkeley Pump Co. The Motor is G.E. Induction Motor, model 5K4256XA3YI, serial no. GAJ728337, Tri-Clad. View looking northeast. - Prairie Creek Fish Hatchery, Hwy. 101, Orick, Humboldt County, CA

  9. Discovery of a spawning ground reveals diverse migration strategies in Atlantic bluefin tuna (Thunnus thynnus).

    PubMed

    Richardson, David E; Marancik, Katrin E; Guyon, Jeffrey R; Lutcavage, Molly E; Galuardi, Benjamin; Lam, Chi Hin; Walsh, Harvey J; Wildes, Sharon; Yates, Douglas A; Hare, Jonathan A

    2016-03-22

    Atlantic bluefin tuna are a symbol of both the conflict between preservationist and utilitarian views of top ocean predators, and the struggle to reach international consensus on the management of migratory species. Currently, Atlantic bluefin tuna are managed as an early-maturing eastern stock, which spawns in the Mediterranean Sea, and a late-maturing western stock, which spawns in the Gulf of Mexico. However, electronic tagging studies show that many bluefin tuna, assumed to be of a mature size, do not visit either spawning ground during the spawning season. Whether these fish are spawning in an alternate location, skip-spawning, or not spawning until an older age affects how vulnerable this species is to anthropogenic stressors including exploitation. We use larval collections to demonstrate a bluefin tuna spawning ground in the Slope Sea, between the Gulf Stream and northeast United States continental shelf. We contend that western Atlantic bluefin tuna have a differential spawning migration, with larger individuals spawning in the Gulf of Mexico, and smaller individuals spawning in the Slope Sea. The current life history model, which assumes only Gulf of Mexico spawning, overestimates age at maturity for the western stock. Furthermore, individual tuna occupy both the Slope Sea and Mediterranean Sea in separate years, contrary to the prevailing view that individuals exhibit complete spawning-site fidelity. Overall, this complexity of spawning migrations questions whether there is complete independence in the dynamics of eastern and western Atlantic bluefin tuna and leads to lower estimates of the vulnerability of this species to exploitation and other anthropogenic stressors. PMID:26951668

  10. Discovery of a spawning ground reveals diverse migration strategies in Atlantic bluefin tuna (Thunnus thynnus)

    PubMed Central

    Richardson, David E.; Marancik, Katrin E.; Guyon, Jeffrey R.; Lutcavage, Molly E.; Galuardi, Benjamin; Lam, Chi Hin; Walsh, Harvey J.; Wildes, Sharon; Yates, Douglas A.; Hare, Jonathan A.

    2016-01-01

    Atlantic bluefin tuna are a symbol of both the conflict between preservationist and utilitarian views of top ocean predators, and the struggle to reach international consensus on the management of migratory species. Currently, Atlantic bluefin tuna are managed as an early-maturing eastern stock, which spawns in the Mediterranean Sea, and a late-maturing western stock, which spawns in the Gulf of Mexico. However, electronic tagging studies show that many bluefin tuna, assumed to be of a mature size, do not visit either spawning ground during the spawning season. Whether these fish are spawning in an alternate location, skip-spawning, or not spawning until an older age affects how vulnerable this species is to anthropogenic stressors including exploitation. We use larval collections to demonstrate a bluefin tuna spawning ground in the Slope Sea, between the Gulf Stream and northeast United States continental shelf. We contend that western Atlantic bluefin tuna have a differential spawning migration, with larger individuals spawning in the Gulf of Mexico, and smaller individuals spawning in the Slope Sea. The current life history model, which assumes only Gulf of Mexico spawning, overestimates age at maturity for the western stock. Furthermore, individual tuna occupy both the Slope Sea and Mediterranean Sea in separate years, contrary to the prevailing view that individuals exhibit complete spawning-site fidelity. Overall, this complexity of spawning migrations questions whether there is complete independence in the dynamics of eastern and western Atlantic bluefin tuna and leads to lower estimates of the vulnerability of this species to exploitation and other anthropogenic stressors. PMID:26951668

  11. Spawning Sites of the Japanese Eel in Relation to Oceanographic Structure and the West Mariana Ridge

    PubMed Central

    Aoyama, Jun; Watanabe, Shun; Miller, Michael J.; Mochioka, Noritaka; Otake, Tsuguo; Yoshinaga, Tatsuki; Tsukamoto, Katsumi

    2014-01-01

    The Japanese eel, Anguilla japonica, spawns within the North Equatorial Current that bifurcates into both northward and southward flows in its westward region, so its spawning location and larval transport dynamics seem important for understanding fluctuations in its recruitment to East Asia. Intensive research efforts determined that Japanese eels spawn along the western side of the West Mariana Ridge during new moon periods, where all oceanic life history stages have been collected, including eggs and spawning adults. However, how the eels decide where to form spawning aggregations is unknown because spawning appears to have occurred at various latitudes. A salinity front formed from tropical rainfall was hypothesized to determine the latitude of its spawning locations, but an exact spawning site was only found once by collecting eggs in May 2009. This study reports on the collections of Japanese eel eggs and preleptocephali during three new moon periods in June 2011 and May and June 2012 at locations indicating that the distribution of lower salinity surface water or salinity fronts influence the latitude of spawning sites along the ridge. A distinct salinity front may concentrate spawning south of the front on the western side of the seamount ridge. It was also suggested that eels may spawn at various latitudes within low-salinity water when the salinity fronts appeared unclear. Eel eggs were distributed within the 150–180 m layer near the top of the thermocline, indicating shallow spawning depths. Using these landmarks for latitude (salinity front), longitude (seamount ridge), and depth (top of the thermocline) to guide the formation of spawning aggregations could facilitate finding mates and help synchronize their spawning. PMID:24551155

  12. Repeat surveys of spawning cisco (Coregonus artedi) in western Lake Superior: timing, distribution and composition of spawning stocks

    USGS Publications Warehouse

    Yule, Daniel L.; Schreiner, Donald R.; Addison, Peter A.; Seider, Michael J.; Evrard, Lori M.; Geving, Steven A.; Quinlan, Henry R.

    2012-01-01

    Acoustic (AC) and midwater trawl (MT) surveys of spawning cisco (Coregonus artedi) in Lake Superior have been combined with commercial yield to estimate exploitation. To time surveys properly, it is important to understand when adults typically arrive at spawning grounds and how numbers change as the spawning season progresses. We conducted repeat autumn surveys during nighttime hours at coastal sites where commercial roe fisheries occur. Spawner densities increased significantly from October to mid-November, but differences measured at sites sampled from mid- to late-November were comparatively small. Spawners occupied the upper 20–30 m of the water column during mid-November before utilizing a wider range of depths by late-November. We compared repeat AC densities to temporal trends of catch-per-unit-effort (CPUE) in suspended commercial gillnets and found good agreement within sites. Because different gillnet mesh sizes were used in each roe fishery. CPUE and AC density were poorly correlated among sites. We recommend that future surveys be conducted between mid- and late-November, and that MT gear be used to measure cisco densities in the uppermost 10 m of the water column where AC estimates may be conservative. Given the short temporal window for assessing spawner density, we believe both AC-MT and gillnet surveys will be needed to ensure that harvest of different stocks is kept at a sustainable level.

  13. Confirmation of ovarian homogeneity in post-vitellogenic cultured white sturgeon, Acipenser transmontanus.

    PubMed

    Talbott, Mariah J; Servid, Sarah A; Cavinato, Anna G; Van Eenennaam, Joel P; Doroshov, Serge I; Struffenegger, Peter; Webb, Molly A H

    2014-02-01

    Assessing stage of oocyte maturity in female sturgeon by calculating oocyte polarization index (PI) is a necessary tool for both conservation propagation managers and caviar producers to know when to hormonally induce spawning. We tested the assumption that sampling ovarian follicles from one section of one ovary is sufficient for calculating an oocyte PI representative of oocyte maturity for an individual animal. Short-wavelength near-infrared spectroscopy (SW-NIR) scans were performed on three positions per ovary for five fish prior to caviar harvest. Samples of ovarian follicles were subsequently taken from the exact location of the SW-NIR scans for calculation of oocyte PI and follicle diameter. Oocyte PI was statistically different though not biologically relevant within an ovary and between ovaries in four of five fish. Follicle diameter was statistically different but not biologically relevant within an ovary in three of five fish. There were no differences in follicle diameter between ovaries. No statistical differences were observed between SW-NIR spectra collected at different locations within an ovary or between ovaries. These results emphasize the importance of utilizing both oocyte PI measurement and progesterone-induced oocyte maturation assays while deciding when to hormonally induce spawning in sturgeon females. PMID:24174166

  14. Columbia River White Sturgeon (Acipenser Transmontanus) Enhancement, May 1-December 31, 1983 Final Report.

    SciTech Connect

    Brannon, E.L.

    1984-12-01

    Studies were undertaken to examine and define the early life history characteristics of Columbia River white sturgeon as a working base from which enhancement measures could be developed. Adult sturgeon were captured and held for spawning at Covert's Landing, the site of the hatchery facilities below Bonneville Dam. Pituitary hormones stimulated ovulation; ripe females were live spawned surgically and the eggs incubated in hatching jars. Larvae were either reared at the hatchery site after incubation to advanced fingerling stages or transferred to the University laboratory for more detailed study. Displacement downstream occurs as a means of distribution and can last several days before a strong substrate preference is manifested. Once bottom contact is sought by the larvae, displacement is abated, and a general preference for sandy surface appears to predominate. Since potentially extensive displacement downstream could result in the distribution of larvae in saltwater, the tolerance of young sturgeon to saltwater was examined. The responsiveness of young sturgeon to artificial feed was positive. With these results, the original concern for identifying an adequate diet and food source that would be readily accepted by fry was greatly attenuated. The readiness of young fry to initiate feeding on the artificial diet made further study on feeding stimulants unnecessary. Examination of the feeding response suggested that as long as the diet used in the present study was initiated at the proper time and with adequate frequency, the fry would feed quite well and survive. 6 refs., 10 figs., 5 tabs.

  15. Acipensins – Novel Antimicrobial Peptides from Leukocytes of the Russian Sturgeon Acipenser gueldenstaedtii

    PubMed Central

    Shamova, O. V.; Orlov, D. S.; Balandin, S. V.; Shramova, E. I.; Tsvetkova, E. V.; Panteleev, P. V.; Leonova, Yu. F.; Tagaev, A. A.; Kokryakov, V. N.; Ovchinnikova, T. V.

    2014-01-01

    Antimicrobial peptides (AMPs) play an important role in the innate defense mechanisms in humans and animals. We have isolated and studied a set of antimicrobial peptides from leukocytes of the Russian sturgeon Acipenser gueldenstaedtii belonging to a subclass of chondrosteans, an ancient group of bony fish. Structural analysis of the isolated peptides, designated as acipensins (Ac), revealed in leukocytes of the Russian sturgeon six novel peptides with molecular masses of 5336.2 Da, 3803.0 Da, 5173.0 Da, 4777.5 Da, 5449.4 Da, and 2740.2 Da, designated as Ac1–Ac6, respectively. Complete primary structures of all the isolated peptides were determined, and the biological activities of three major components – Ac1, Ac2, and Ac6 – were examined. The peptides Ac1, Ac2, Ac3, Ac4, and Ac5 were found to be the N-terminal acetylated fragments 1–0, 1–5, 1–9, 1–4, and 1–1 of the histone H2A, respectively, while Ac6 was shown to be the 62–5 fragment of the histone H2A. The peptides Ac1 and Ac2 displayed potent antimicrobial activity towards Gram-negative and Gram-positive bacteria (Escherichia coli ML35p, Listeria monocytogenes EGD, MRSA ATCC 33591) and the fungus Candida albicans 820, while Ac6 proved effective only against Gram-negative bacteria. The efficacy of Ac 1 and Ac2 towards the fungus and MRSA was reduced upon an increase in the ionic strength of the solution. Ac1, Ac2, and Ac6, at concentrations close to their minimum inhibitory concentrations, enhanced the permeability of the E.coli ML35p outer membrane to the chromogenic marker, but they did not affect appreciably the permeability of the bacterial inner membrane in comparison with a potent pore-forming peptide, protegrin 1. Ac1, Ac2, and Ac6 revealed no hemolytic activity against human erythrocytes at concentrations of 1 to 40 μM and had no cytotoxic effect (1 to 20 μM) on K-562 and U-937 cells in vitro. Our findings suggest that histone-derived peptides serve as important anti-infective host

  16. Electrical excitability of the heart in a Chondrostei fish, the Siberian sturgeon (Acipenser baerii).

    PubMed

    Haworth, Thomas Eliot; Haverinen, Jaakko; Shiels, Holly A; Vornanen, Matti

    2014-11-01

    Sturgeon (family Acipenseridae) are regarded as living fossils due to their ancient origin and exceptionally slow evolution. To extend our knowledge of fish cardiac excitability to a Chondrostei fish, we examined electrophysiological phenotype of the Siberian sturgeon (Acipenser baerii) heart with recordings of epicardial ECG, intracellular action potentials (APs), and sarcolemmal ion currents. Epicardial ECG of A. baerii had the typical waveform of the vertebrate ECG with Q-T interval (average duration of ventricular AP) of 650±30 ms and an intrinsic heart rate of 45.5±5 beats min(-1) at 20°C. Similar to other fish species, atrial AP was shorter in duration (402±33 ms) than ventricular AP (585±40) (P<0.05) at 20°C. Densities of atrial and ventricular Na+ currents were similar (-47.6±4.5 and -53.2±5.1 pA/pF, respectively) and close to the typical values of teleost hearts. Two major K+ currents, the inward rectifier K+ current (IK1), and the delayed rectifier K+ current (IKr) were found under basal conditions in sturgeon cardiomyocytes. The atrial IKr (3.3±0.2 pA/pF) was about twice as large as the ventricular IKr (1.3±0.4 pA/pF) (P<0.05) conforming to the typical pattern of teleost cardiac IKr. Divergent from other fishes, the ventricular IK1 was remarkably small (-2.5±0.07 pA/pF) and not different from that of the atrial myocytes (-1.9±0.06 pA/pF) (P>0.05). Two ligand-gated K+ currents were also found: ACh-activated inward rectifier (IKACh) was present only in atrial cells, while ATP-sensitive K+ current (IKATP) was activated by a mitochondrial blocker, CCCP, in both atrial and ventricular cells. The most striking difference to other fishes appeared in Ca2+ currents (ICa). In atrial myocytes, ICa was predominated by nickel-sensitive and nifedipine-resistant T-type ICa, while ventricular myocytes had mainly nifedipine-sensitive and nickel-resistant L-type ICa. ICaT/ICaL ratio of the sturgeon atrial myocytes (2.42) is the highest value ever measured for

  17. Sterilization of sterlet Acipenser ruthenus by using knockdown agent, antisense morpholino oligonucleotide, against dead end gene.

    PubMed

    Linhartová, Zuzana; Saito, Taiju; Kašpar, Vojtěch; Rodina, Marek; Prášková, Eva; Hagihara, Seishi; Pšenička, Martin

    2015-10-15

    Sturgeons (chondrostean, acipenseridae) are ancient fish species, widely known for their caviar. Nowadays, most of them are critically endangered. The sterlet (Acipenser ruthenus) is a common Eurasian sturgeon species with a small body size and the fastest reproductive cycle among sturgeons. Such species can be used as a host for surrogate production; application is of value for recovery of critically endangered and huge sturgeon species with an extremely long reproductive cycle. One prerequisite for production of the donor's gametes only is to have a sterile host. Commonly used sterilization techniques in fishes such as triploidization or hybridization do not guarantee sterility in sturgeon. Alternatively, sterilization can be achieved by using a temporary germ cell exclusion-specific gene by a knockdown agent, the antisense morpholino oligonucleotide (MO). The targeted gene for the MO is the dead end gene (dnd) which is a vertebrate-specific gene encoding a RNA-binding protein which is crucial for migration and survival of primordial germ cells (PGCs). For this purpose, a dnd homologue of Russian sturgeon (Agdnd), resulting in the same sequence in the start codon region with isolated fragments of sterlet dnd (Ardnd), was used. Reverse transcription polymerase chain reaction confirmed tissue-specific expression of Ardnd only in the gonads of both sexes. Dnd-MO for depletion of PGCs together with fluorescein isothiocyanate (FITC)-biotin-dextran for PGCs labeling was injected into the vegetal region of one- to four-cell-stage sterlet embryos. In the control groups, only FITC was injected to validate the injection method and labeling of PGCs. After optimization of MO concentration together with volume injection, 250-μM MO was applied for sterilization of sturgeon embryos. Primordial germ cells were detected under a fluorescent stereomicroscope in the genital ridge of the FITC-labeled control group only, whereas no PGCs were present in the body cavities of morphants

  18. Effects of Temperature on In Vitro Short-Term Storage of Sterlet Sturgeon (Acipenser Ruthenus) Ova.

    PubMed

    Linhart, O; Shelton, W L; Tučková, V; Rodina, M; Siddique, Mam

    2016-02-01

    Artificial propagation of sturgeons is becoming increasingly important for recovery efforts as well as for commercial production. Sterlet Acipenser ruthenus is a common Eurasian sturgeon with a small body size and one of the fastest reproductive cycles among the sturgeons. The practical question being addressed in this study was how long fertilization of ovulated eggs can be delayed without substantially reducing the hatching rate, and an ancillary question is under what' temperature conditions do eggs retain good quality. Broodstock were injected with homogenized carp pituitary extract (CPE); ovulated eggs from three females were allocated to various treatment groups for temperature storage (control, 7°C, 11°C, 15°C and 19°C) until fertilized. Storage times at the regulated temperatures prior to fertilization were for 2.5, 5.0, 7.5 and 10.0 h. After the selected storage times in ovarian fluid, eggs were fertilized and transferred to incubation cages and then they were counted. Three replicates were allocated to each storage period and temperature. Hatched larvae were counted at 7-day post-fertilization. We found that sterlet eggs do not need to be fertilized immediately after collection. Reasonably good quality was retained for several hours if temperature conditions are fairly cool and stable. Eggs retained good quality when stored at 7°C and 11°C for up to 10 h with 54.1 ± 2.9 to 69.9 ± 7.9% hatching success, but egg quality was significantly reduced after 5-h storage at 19°C (p < 0.01) and 7.5-h storage at 15°C (p < 0.05) compared to cooler temperatures. Uniform temperatures between 7°C and 11°C can be considered as appropriate for storage of eggs in ovarian fluid for up to 10 h. This information can have practical application to routine hatchery practice for acipenserids, as well as for certain research protocols. PMID:26708725

  19. Is hepatic oxidative stress a main driver of dietary selenium toxicity in white sturgeon (Acipenser transmontanus)?

    PubMed

    Zee, Jenna; Patterson, Sarah; Wiseman, Steve; Hecker, Markus

    2016-11-01

    Most species of sturgeon have experienced significant population declines and poor recruitment over the past decades, leading many, including white sturgeon (Acipenser transmontanus), to be listed as endangered. Reasons for these declines are not yet fully understood but benthic lifestyle, longevity, and delayed sexual maturation likely render sturgeon particularly susceptible to factors such as habitat alteration and contaminant exposures. One contaminant of particular concern to white sturgeon is selenium (Se), especially in its more bioavailable form selenomethionine (SeMet), as it is known to efficiently bioaccumulate in prey items of this species. Studies have shown white sturgeon to be among the most sensitive species of fish to dietary SeMet as well as other pollutants such as metals, dioxin-like chemicals and endocrine disrupters. One of the primary hypothesized mechanisms of toxicity of SeMet in fish is oxidative stress; however, little is know about the specific mode by which SeMet affects the health of white sturgeon. Therefore, the aim of this study was to characterize oxidative stress and associated antioxidant responses as a molecular event of toxicity, and to link it with the pathological effects observed previously. Specifically, three-year-old white sturgeon were exposed for 72 days via their diet to 1.4, 5.6, 22.4 or 104.4µg Se per g feed (dm). Doses were chosen to range over a necessary Se intake level, current environmentally relevant intakes and an intake representing predicted increases of Se release. Lipid hydroperoxides, which are end products of lipid oxidation, were quantified as a marker of oxidative stress. Changes in gene expression of glutathione peroxidase (GPx), superoxide dismutase, catalase, glutathione S-transferase, apoptosis inducing factor and caspase 3 were quantified as markers of the response to oxidative stress. Concentrations of lipid hydroperoxides were highly variable within dose groups and no dose response was observed

  20. An 'optimal' spawning algorithm for adaptive basis set expansion in nonadiabatic dynamics

    SciTech Connect

    Yang, Sandy; Coe, Joshua D.; Kaduk, Benjamin; Martinez, Todd J.

    2009-04-07

    The full multiple spawning (FMS) method has been developed to simulate quantum dynamics in the multistate electronic problem. In FMS, the nuclear wave function is represented in a basis of coupled, frozen Gaussians, and a 'spawning' procedure prescribes a means of adaptively increasing the size of this basis in order to capture population transfer between electronic states. Herein we detail a new algorithm for specifying the initial conditions of newly spawned basis functions that minimizes the number of spawned basis functions needed for convergence. 'Optimally' spawned basis functions are placed to maximize the coupling between parent and child trajectories at the point of spawning. The method is tested with a two-state, one-mode avoided crossing model and a two-state, two-mode conical intersection model.

  1. Spawning Distribution of Fall Chinook Salmon in the Snake River : Annual Report 1998.

    SciTech Connect

    Garcia, Aaron P.

    1999-03-01

    In 1998 data was collected on the spawning distribution of the first adult fall chinook salmon to return from releases of yearling hatchery fish upriver of Lower Granite Dam. Yearling fish were released at three locations with the intent of distributing spawning throughout the existing habitat. The project was designed to use radio-telemetry to determine if the use of multiple release sites resulted in widespread spawning.

  2. Pattern of shoreline spawning by sockeye salmon in a glacially turbid lake: evidence for subpopulation differentiation

    USGS Publications Warehouse

    Burger, C.V.; Finn, J.E.; Holland-Bartels, L.

    1995-01-01

    Alaskan sockeye salmon typically spawn in lake tributaries during summer (early run) and along clear-water lake shorelines and outlet rivers during fall (late run). Production at the glacially turbid Tustumena Lake and its outlet, the Kasilof River (south-central Alaska), was thought to be limited to a single run of sockeye salmon that spawned in the lake's clear-water tributaries. However, up to 40% of the returning sockeye salmon enumerated by sonar as they entered the lake could not be accounted for during lake tributary surveys, which suggested either substantial counting errors or that a large number of fish spawned in the lake itself. Lake shoreline spawning had not been documented in a glacially turbid system. We determined the distribution and pattern of sockeye salmon spawning in the Tustumena Lake system from 1989 to 1991 based on fish collected and radiotagged in the Kasilof River. Spawning areas and time were determined for 324 of 413 sockeye salmon tracked upstream into the lake after release. Of these, 224 fish spawned in tributaries by mid-August and 100 spawned along shoreline areas of the lake during late August. In an additional effort, a distinct late run was discovered that spawned in the Kasilof River at the end of September. Between tributary and shoreline spawners, run and spawning time distributions were significantly different. The number of shoreline spawners was relatively stable and independent of annual escapement levels during the study, which suggests that the shoreline spawning component is distinct and not surplus production from an undifferentiated run. Since Tustumena Lake has been fully deglaciated for only about 2,000 years and is still significantly influenced by glacier meltwater, this diversification of spawning populations is probably a relatively recent and ongoing event.

  3. Documentation of a Gulf sturgeon spawning site on the Yellow River, Alabama, USA

    USGS Publications Warehouse

    Kreiser, Brian R.; Berg, J.; Randall, M.; Parauka, F.; Floyd, S.; Young, B.; Sulak, Kenneth J.

    2008-01-01

    Parauka and Giorgianni (2002) reported that potential Gulf sturgeon spawning habitat is present in the Yellow River; however, efforts to document spawning by the collection of eggs or larvae have been unsuccessful in the past. Herein, we report on the first successful collection of eggs from a potential spawning site on the Yellow River and the verification of their identity as Gulf sturgeon by using molecular methods.

  4. Spawning behavior in Atlantic cod: analysis by use of data storage tags

    USGS Publications Warehouse

    Grabowski, Timothy B.; Thorsteinsson, Vilhjalmur; Marteinsdóttir, Gudrún

    2014-01-01

     Electronic data storage tags (DSTs) were implanted into Atlantic cod captured in Icelandic waters from 2002 to 2007 and the depth profiles recovered from these tags (females: n = 31, males: n = 27) were used to identify patterns consistent with published descriptions of cod courtship and spawning behavior. The individual periods of time that males spent exhibiting behavior consistent with being present in a spawning aggregation—i.e. periods consisting of a clear tidal signature in the DST depth profile associated with an individual remaining on or near the substrate—were longer than those of females. Over the course of a spawning season, male cod spent approximately twice the amount of time in spawning aggregations than females, but female cod visited more aggregations per unit time. On average, males participated in approximately 57% more putative spawning events, i.e. vertical ascents potentially corresponding to gamete release, than did females. However, males <85 cm total length participated in the same number of putative spawning events as females of comparable size. In both sexes, larger individuals and/or individuals that spent a longer period of time within an aggregation participated in a larger number of putative spawning events. Although further validation and refinement is necessary, particularly in the identification of spawning events, the ability offered by DSTs to quantify cod spawning behavior may aid in the development of management and conservation plans.

  5. Association between geomorphic attributes of watersheds, water temperature, and salmon spawn timing in Alaskan streams

    NASA Astrophysics Data System (ADS)

    Lisi, Peter J.; Schindler, Daniel E.; Bentley, Kale T.; Pess, George R.

    2013-03-01

    Intraspecific variation in the seasonal reproductive timing of Pacific salmon (Oncorhynchus sp.) has important implications for the resilience of salmon and for organisms in freshwater and terrestrial communities that depend on salmon resources. Stream temperature has well known associations with salmon spawn timing but how stream and watershed geomorphology relates to the variation in salmon spawn timing is less understood. We used multivariate statistics applied to five environmental variables to compare conditions across 36 watersheds in the Wood River basin in southwest Alaska. We found that the environmental conditions in the first two axes of a principal components analysis (PCA) explained 76% of the variation in summer temperature among streams and 45% of the variation in spawn timing of sockeye salmon. The average habitat characteristics of streams that characterized three spawn timing groups of sockeye salmon were significantly distinct from one another. Sites supporting early spawning populations tend to have steeper and smaller watersheds, while late spawning populations occur in streams draining large, lower gradient watersheds with lakes in the drainage network. Finally, we show that stream temperature and spawn timing among streams have little spatial correlation across the landscape, thereby producing a fine-scale mosaic of spawn timing across the river basin. These results demonstrate that geomorphology and hydrology interact to produce a heterogeneous thermal template for natural selection to influence salmon spawn timing across river basins.

  6. Multi-species spawning synchrony within scleractinian coral assemblages in the Red Sea

    NASA Astrophysics Data System (ADS)

    Bouwmeester, J.; Baird, A. H.; Chen, C. J.; Guest, J. R.; Vicentuan, K. C.; Berumen, M. L.

    2015-03-01

    Early work on coral reproduction in the far northern Red Sea suggested that the spawning times of ecologically abundant species did not overlap, unlike on the Great Barrier Reef where many species spawn with high synchrony. In contrast, recent work in the northern and central Red Sea indicates a high degree of synchrony in the reproductive condition of Acropora species: over 90 % of species sampled in April/May contain mature gametes. However, it has yet to be determined when most Acropora release their gametes. In addition, there is a lack of data for other ecologically important scleractinian species such as merulinids and poritids. Here, we document the date and time of spawning for 51 species in the central Red Sea over three consecutive years, and the month of spawning for an additional 17 species inferred from the presence of mature gametes. Spawning occurs on nights around the full moon, the spawning season lasts at least 4 months from April until July, and observations are consistent with the few other records from the Red Sea. The number of Acropora species spawning was highest in April with 13 species spawning two nights before the full moon in 2011, 13 species spawning on the night of the full moon in 2012, and eight species spawning four nights after the full moon in 2013. The total number of species spawning was high in April, May, and June and involved 15-19 species per month in 2012. Only four species spawned in July 2012. Few regions worldwide have been similarly sampled and include the Philippines, Okinawa in Japan, and Palau, where spawning patterns are very similar to those in the central Red Sea and where corals spawn on nights around the full moon over a period of 3-4 months. In particular, in all four locations, Acropora are among the first species to spawn. Our results add to a growing body of evidence indicating that multi-species spawning synchrony is a feature of all speciose coral assemblages.

  7. A simple method for selecting spawning-ready individuals out from laboratorial cultured amphioxus population.

    PubMed

    Li, Guang; Wang, Jing; Yuan, Liang; Wang, Hui; Wang, Yi-Quan

    2015-11-01

    Amphioxus is an emerging model organism for evolutionary developmental (Evo-Dev) studies owing to its key phylogenetic position in chordates. However, the rare supply of living embryonic materials is a major drawback for using amphioxus as a laboratorial model animal. Although the problem has been partially resolved in several recent reports, the spawning of amphioxus still remains unpredictable to some extent. In the present study, we reported an accurate method to distinguish spawning-ready and non-spawning-ready individuals of amphioxus Branchiostoma belcheri. In comparison with non-spawning-ready amphioxus, all spawning-ready individuals display following features several hours before their spawning: 1) for both males and females, the interstices between two adjacent gonads are obvious and relatively wide; and 2) the connections among eggs are loose and the crannies appear in each individual ovary of females. These morphological features were also observed in B. japonicum, indicating their conservation among different lancelet species. Based on this observable criterion, we made predictions on the spawning of about 600 ripe B. belcheri individuals and acquired an accuracy of 86.7% for females and 80.4% for males. In addition, we found that advancing or delaying onset of darkness has no detectable effect on the timing of spawning of B. belcheri. Our study makes amphioxus spawning more amenable for our experiments and will greatly facilitate its utilization as a laboratorial model animal. PMID:26299898

  8. Use of behavioral and physiological indicators to evaluate Scaphirhynchus sturgeon spawning success

    USGS Publications Warehouse

    DeLonay, A.J.; Papoulias, D.M.; Wildhaber, M.L.; Annis, M.L.; Bryan, J.L.; Griffith, S.A.; Holan, S.H.; Tillitt, D.E.

    2007-01-01

    Thirty gravid, female shovelnose sturgeon (Scaphirhynchus platorynchus) were captured in the Lower Missouri River in March 2004 to evaluate the effectiveness of physiology, telemetry and remote sensor technology coupled with change point analysis in identifying when and where Scaphirhynchus sturgeon spawn. Captured sturgeons were instrumented with ultrasonic transmitters and with archival data storage tags (DST) that recorded temperature and pressure. Female sturgeon were tracked through the suspected spawning period. Thereafter, attempts were made to recapture fish to evaluate spawning success. At the time of transmitter implantation, blood and an ovarian biopsy were taken. Reproductive hormones and cortisol were measured in blood. Polarization indices and germinal vesicle breakdown were assessed on the biopsied oocytes to determine readiness to spawn. Behavioral data collected using telemetry and DST sensors were used to determine the direction and magnitude of possible spawning-related movements and to identify the timing of potential spawning events. Upon recapture observations of the ovaries and blood chemistry provided measures of spawning success and comparative indicators to explain differences in observed behavior. Behavioral and physiological indicators of spawning interpreted along with environmental measures may assist in the determination of variables that may cue sturgeon reproduction and the conditions under which sturgeon successfully spawn. ?? 2007 Blackwell Verlag.

  9. Comparative ontogenetic behavior and migration of kaluga, Huso dauricus, and Amur sturgeon, Acipenser schrenckii, from the Amur River

    USGS Publications Warehouse

    Zhuang, P.; Kynard, B.; Zhang, L.; Zhang, T.; Cao, W.

    2003-01-01

    We conducted laboratory experiments with kaluga, Huso dauricus, and Amur sturgeon, Acipenser schrenckii, to develop a conceptual model of early behavior. We daily observed embryos (first life phase after hatching) and larvae (period initiating exogenous feeding) to day-30 (late larvae) for preference of bright habitat and cover, swimming distance above the bottom, up- and downstream movement, and diel activity. Day-0 embryos of both species strongly preferred bright, open habitat and initiated a strong, downstream migration that lasted 4 days (3 day peak) for kaluga and 3 days (2 day peak) for Amur sturgeon. Kaluga migrants swam far above the bottom (150 cm) on only 1 day and moved day and night; Amur sturgeon migrants swam far above the bottom (median 130 cm) during 3 days and were more nocturnal than kaluga. Post-migrant embryos of both species moved day and night, but Amur sturgeon used dark, cover habitat and swam closer to the bottom than kaluga. The larva period of both species began on day 7 (cumulative temperature degree-days, 192.0 for kaluga and 171.5 for Amur sturgeon). Larvae of both species preferred open habitat. Kaluga larvae strongly preferred bright habitat, initially swam far above the bottom (median 50-105 cm), and migrated downstream at night during days 10-16 (7-day migration). Amur sturgeon larvae strongly avoided illumination, had a mixed response to white substrate, swam 20-30 cm above the bottom during most days, and during days 12-34 (most of the larva period) moved downstream mostly at night (23-day migration). The embryo-larva migration style of the two species likely shows convergence of non-related species for a common style in response to environmental selection in the Amur River. The embryo-larva migration style of Amur sturgeon is unique among Acipenser yet studied.

  10. Cryopreservation of early stage Siberian sturgeon Acipenser baerii germ cells, comparison of whole tissue and dissociated cells.

    PubMed

    Pšenička, Martin; Saito, Taiju; Rodina, Marek; Dzyuba, Boris

    2016-04-01

    Several sturgeon species are near extinction; therefore an efficient conservation strategy is required. Germ stem cells can be used for long-term storage and restoration of genetic information using surrogate reproduction. This study compared cryopreservation procedures of early stages of Siberian sturgeon Acipenser baerii testicular and ovarian cells. Whole gonad tissue or dissociated cells were frozen at a cooling rate of 1 °C/min in phosphate buffered saline with 0.5% bovine serum albumin, 50 mM glucose, and one of four different 1.5 M cryoprotectants: dimethyl sulfoxide, glycerol, ethylene glycol, or dimethyl sulfoxide with propanediol. The number of living cells obtained from 0.1 g of gonadal tissue after freeze/thaw of both whole tissue and dissociated cells was higher using ethylene glycol than with other cryoprotectants. Although there were no differences in the number of living cells in cryopreserved whole tissue vs. dissociated cells, the number of dead cells was lower with whole tissue cryopreservation, indicating that cells that died during freeze/thaw were digested during subsequent enzymatic dissociation. This resulted in more than 90% live cells after freeze/thaw and dissociation. The thawed tissue cryopreserved using ethylene glycol as protectant as well as fresh gonadal tissue were dissociated, and the cells were labelled by PKH26 and transplanted into larvae of sterlet Acipenser ruthenus. Ninety days post-transplant of both fresh and cryopreserved cells, introduced cells proliferated in more than half of the recipients. PMID:26920821

  11. De novo annotation of the immune-enriched transcriptome provides insights into immune system genes of Chinese sturgeon (Acipenser sinensis).

    PubMed

    Zhu, Rong; Du, He-Jun; Li, Shun-Yi; Li, Ya-Dong; Ni, Hong; Yu, Xue-Jing; Yang, Yan-Yan; Fan, Yu-Ding; Jiang, Nan; Zeng, Ling-Bing; Wang, Xing-Guo

    2016-08-01

    Chinese sturgeon (Acipenser sinensis), one of the oldest extant actinopterygian fishes with very high evolutionary, economical and conservation interest, is considered to be one of the critically endangered aquatic animals in China. Up to date, the immune system of this species remains largely undetermined with little sequence information publicly available. Herein, the first comprehensive transcriptome of immune tissues for Chinese sturgeon was characterized using Illumina deep sequencing. Over 67 million high-quality reads were generated and de novo assembled into the final set of 91,739 unique sequences. The annotation pipeline revealed that 25,871 unigenes were successfully annotated in the public databases, of which only 2002 had significant match to the existing sequences for the genus Acipenser. Overall 22,827 unigenes were categorized into 52 GO terms, 12,742 were classified into 26 KOG categories, and 4968 were assigned to 339 KEGG pathways. A more detailed annotation search showed the presence of a notable representation of immune-related genes, which suggests that this non-teleost actinopterygian fish harbors the same intermediates as in the well known immune pathways from mammals and teleosts, such as pattern recognition receptor (PRR) signaling pathway, JAK-STAT signaling pathway, complement and coagulation pathway, T-cell receptor (TCR) and B-cell receptor (BCR) signaling pathways. Additional genetic marker discovery led to the retrieval of 20,056 simple sequence repeats (SSRs) and 327,140 single nucleotide polymorphisms (SNPs). This immune-enriched transcriptome of Chinese sturgeon represents a rich resource that adds to the currently nascent field of chondrostean fish immunogenetics and furthers the conservation and management of this valuable fish. PMID:27368537

  12. Geomorphic controls on fine sediment reinfiltration into salmonid spawning gravels and the implications for spawning habitat rehabilitation

    NASA Astrophysics Data System (ADS)

    Franssen, Jan; Lapointe, Michel; Magnan, Pierre

    2014-04-01

    Anthropogenic activities often increase the flux of fine sediment to fluvial environments. In gravel-bed streams the extent to which augmented fines loading causes the degradation of vital interstitial habitats is determined by factors controlling fines infiltration into channel substratum. Previous research suggests that substrate pore constriction size, intensity of upwelling interstitial flow, and the quantity of fines transported across the bed surface (i.e., exposure dose) are three important factors controlling substrate fines content. Few field studies have investigated the interactive effects of these physical factors. We constructed 17 experimental redds in brook trout spawning microhabitats in a boreal forest stream in Quebec, Canada, to investigate the role of pore constriction size, hyporheic flow, and exposure dose on substrate fines content. To simulate the effect of spawning in coarsening the substrates, redds were partially cleaned of coarse sand and of all fine sediment (< 0.5 mm). Results show that coarse sands and fine gravel (0.5-4 mm; filter class) acted as a filter of percolating fine sediment (< 0.5 mm). We found that this filtering effect (i.e., lower fines density at egg pocket depth) occurred at sites where the proportion of the filter class in the substratum above egg pocket depth exceeded a threshold value of 18%, as indicated by a statistically significant step-function response between fines gradient with depth and the filter class content in the uppermost layers of the bed. Results also indicated that fines content at depth was unrelated to fines exposure. Estimated upward seepage rates were well below the threshold velocity that would inhibit the percolation of medium-grained sand (i.e., 0.5 mm) into the bed. These results suggest that within these gravel-bed spawning substrates the abundance of filter classes was the primary determinant of fines content at depth. This study highlights the importance of considering filter class

  13. A proposed mechanism for turbulent enhancement of broadcast spawning efficiency

    NASA Astrophysics Data System (ADS)

    Crimaldi, J. P.; Browning, H. S.

    2004-08-01

    The broadcast spawning reproductive strategy relies on turbulent-stirring processes in the flow to bring together gametes previously released by adult males and females. The subsequent fertilization rate depends on the product of co-occurring concentrations of egg and sperm. Turbulent mixing produces a strong average dilution in these concentrations, suggesting that an increase in turbulence would reduce the average local fertilization rate. However, turbulent dilution occurs at time scales that may be long compared to those associated with fertilization. Therefore, the instantaneous structure of egg and sperm filaments at shorter time scales must be considered. In this paper, a mechanism is proposed whereby coherent turbulent structures in the velocity field cause coalescence between high-concentration filaments of egg and sperm, significantly enhancing the average fertilization rate. Simple analytical and numerical models are used to demonstrate how the mechanism works, and to make qualitative estimates of its effect on the resulting fertilization rate. The results suggest that the efficiency of broadcast spawning is a consequence of features in the instantaneous turbulent field, and that this efficiency is not captured by models that consider only time-averaged features of the flow.

  14. Quantification of coral sperm collected during a synchronous spawning event.

    PubMed

    Teo, Aaron; Guest, James R; Neo, Mei Lin; Vicentuan, Kareen; Todd, Peter A

    2016-01-01

    Most studies of coral reproductive biology to date have focused on oocyte numbers and sizes. Only one (ex situ) study has enumerated sperm numbers, even though these data have multiple potential applications. We quantified total coral sperm and eggs per gamete bundle collected from six species in situ during a synchronous spawning event in Singapore. Egg-sperm bundles were captured midwater as they floated towards the surface after being released by the colony. For each sample, a semi-transparent soft plastic bottle was squeezed and released to create a small suction force that was used to 'catch' the bundles. This technique provided several advantages over traditional methods, including low cost, ease of use, no diving prior to the night of collection needed, and the ability to target specific areas of the colony. The six species sampled were Echinophyllia aspera, Favites abdita, F. chinensis, Merulina ampliata, M. scabricula and Platygyra pini. The mean number of sperm packaged within one egg-sperm bundle ranged from 2.04 × 10(6) to 1.93 × 10(7). The mean number of eggs per egg-sperm bundle ranged from 26.67 (SE ± 3.27) to 85.33 (SE ± 17.79). These data are critical for fertilisation success models, but the collection technique described could also be applied to studies requiring in situ spawning data at the polyp level. PMID:27478697

  15. Quantification of coral sperm collected during a synchronous spawning event

    PubMed Central

    Teo, Aaron; Guest, James R.; Neo, Mei Lin; Vicentuan, Kareen

    2016-01-01

    Most studies of coral reproductive biology to date have focused on oocyte numbers and sizes. Only one (ex situ) study has enumerated sperm numbers, even though these data have multiple potential applications. We quantified total coral sperm and eggs per gamete bundle collected from six species in situ during a synchronous spawning event in Singapore. Egg-sperm bundles were captured midwater as they floated towards the surface after being released by the colony. For each sample, a semi-transparent soft plastic bottle was squeezed and released to create a small suction force that was used to ‘catch’ the bundles. This technique provided several advantages over traditional methods, including low cost, ease of use, no diving prior to the night of collection needed, and the ability to target specific areas of the colony. The six species sampled were Echinophyllia aspera, Favites abdita, F. chinensis, Merulina ampliata, M. scabricula and Platygyra pini. The mean number of sperm packaged within one egg-sperm bundle ranged from 2.04 × 106 to 1.93 × 107. The mean number of eggs per egg-sperm bundle ranged from 26.67 (SE ± 3.27) to 85.33 (SE ± 17.79). These data are critical for fertilisation success models, but the collection technique described could also be applied to studies requiring in situ spawning data at the polyp level. PMID:27478697

  16. Influences of fluctuating flows on spawning habitat and recruitment success

    NASA Astrophysics Data System (ADS)

    Orth, D. J.; Krause, C. W.; Novinger, D. C.

    2005-05-01

    Over the 50 years of daily peak power generation, no ramping restrictions, and loss of gravel due to operations of Philpott Dam, on Smith River, has created a wider, rectangular-shaped channel, with steeper banks. The pattern caused by channel degradation, tributary headcutting, bank erosion, and downstream aggradation has limited the length of productive habitat to between 3 and 10 river kilometers from the dam. Here the channel appears to contain key habitats where we found the highest redd densities, abundance, and spawner biomass for brown trout (Salmo trutta). Recruitment of brown trout to the fishable size classes is constrained by the daily hydropower peaking operations. The number of young brown trout produced each year was strongly related to the average magnitude of the peak flow and the duration of generation flows. Magnitude of peak flows also depressed abundance of native fishes. Although, brown trout actively removed fine sediment via redd construction and spawning, thereby increasing gravel permeability, the fine sediments from tributaries and bank erosion rapidly intruded into the spawning gravel in downstream reaches of the river. We recommend mitigating the effects of fluctuating releases from Philpott Dam through a combination of flow management and habitat improvement.

  17. Passive acoustic monitoring to detect spawning in large-bodied catostomids

    USGS Publications Warehouse

    Straight, Carrie A.; Freeman, Byron J.; Freeman, Mary C.

    2014-01-01

    Documenting timing, locations, and intensity of spawning can provide valuable information for conservation and management of imperiled fishes. However, deep, turbid or turbulent water, or occurrence of spawning at night, can severely limit direct observations. We have developed and tested the use of passive acoustics to detect distinctive acoustic signatures associated with spawning events of two large-bodied catostomid species (River Redhorse Moxostoma carinatum and Robust Redhorse Moxostoma robustum) in river systems in north Georgia. We deployed a hydrophone with a recording unit at four different locations on four different dates when we could both record and observe spawning activity. Recordings captured 494 spawning events that we acoustically characterized using dominant frequency, 95% frequency, relative power, and duration. We similarly characterized 46 randomly selected ambient river noises. Dominant frequency did not differ between redhorse species and ranged from 172.3 to 14,987.1 Hz. Duration of spawning events ranged from 0.65 to 11.07 s, River Redhorse having longer durations than Robust Redhorse. Observed spawning events had significantly higher dominant and 95% frequencies than ambient river noises. We additionally tested software designed to automate acoustic detection. The automated detection configurations correctly identified 80–82% of known spawning events, and falsely indentified spawns 6–7% of the time when none occurred. These rates were combined over all recordings; rates were more variable among individual recordings. Longer spawning events were more likely to be detected. Combined with sufficient visual observations to ascertain species identities and to estimate detection error rates, passive acoustic recording provides a useful tool to study spawning frequency of large-bodied fishes that displace gravel during egg deposition, including several species of imperiled catostomids.

  18. Temporal patterns and behavioral characteristics of aggregation formation and spawning in the Bermuda chub ( Kyphosus sectatrix)

    NASA Astrophysics Data System (ADS)

    Nemeth, Richard S.; Kadison, Elizabeth

    2013-12-01

    Reef fish spawning aggregations are important life history events that occur at specific times and locations and represent the primary mode of reproduction for many species. This paper provides detailed descriptions of aggregation formation and mass spawning of the Bermuda chub ( Kyphosus sectatrix). Spawning coloration and gamete release of K. sectatrix were observed and filmed at the Grammanik Bank, a deep spawning aggregation site used by many different species located on the southern edge of the Puerto Rican shelf 10 km south of St. Thomas, US Virgin Islands. Underwater visual surveys using technical Nitrox and closed circuit re-breathers were conducted from December 2002 to March 2013 and documented spatial and temporal patterns of movement and aggregation formation along 1.5 km of mesophotic reef. The largest aggregations of K. sectatrix (>200 fish) were observed on the Grammanik Bank January to March from 0 to 11 d after the full moon with peak abundance from 60 to 80 d after the winter solstice across all survey years. Aggregation formation of K. sectatrix coincided with the spawning season of Nassau ( Epinephelus striatus) and yellowfin ( Mycteroperca venenosa) groupers. These spatial and temporal patterns of aggregation formation and spawning suggest that K. sectatrix, an herbivore, may also be a transient aggregating species. On several occasions, chubs were observed both pair spawning and mass spawning. Color patterns and behaviors associated with aggregation and spawning are described and compared to spawning characteristics observed in other species, many of which are similar but others that appear unique to K. sectatrix. This represents the first report of a kyphosid species aggregating to spawn and illuminates a portion of the poorly understood life history of the Bermuda chub.

  19. Optimum Pathways of Fish Spawning Migrations in Rivers

    NASA Astrophysics Data System (ADS)

    McElroy, B. J.; Jacobson, R. B.; Delonay, A.

    2010-12-01

    Many fish species migrate large distances upstream in rivers to spawn. These migrations require energetic expenditures that are inversely related to fecundity of spawners. Here we present the theory necessary to quantify relative energetic requirements of upstream migration pathways and then test the hypothesis that least-cost paths are taken by the federally endangered pallid sturgeon (Scaphyrhyncus Albus), a benthic rheophile, in the lower Missouri River, USA. Total work done by a fish through a migratory path is proportional to the size of the fish, the total drag on the fish, and the distance traversed. Normalizing by the work required to remain stationary at the beginning of a path, relative work expenditure at each point of the path is found to be the cube of the ratio of the velocity along the path to the velocity at the start of the path. This is the velocity of the fish relative to the river flow. A least-cost migratory pathway can be determined from the velocity field in a reach as the path that minimizes a fish's relative work expenditure. We combine location data from pallid sturgeon implanted with telemetric tags and pressure-sensitive data storage tags with depth and velocity data collected with an acoustic Doppler profiler. During spring 2010 individual sturgeon were closely followed as they migrated up the Missouri River to spawn. These show that, within a small margin, pallid sturgeon in the lower Missouri River select least-cost paths as they swim upstream (typical velocities near 1.0 - 1.2 m/s). Within the range of collected data, it is also seen that many alternative paths not selected for migration are two orders of magnitude more energetically expensive (typical velocities near 2.0 - 2.5 m/s). In general these sturgeon migrated along the inner banks of bends avoiding high velocities in the thalweg, crossing the channel where the thalweg crosses in the opposite direction in order to proceed up the inner bank of subsequent bends. Overall, these

  20. Migration and spawning of female surubim (Pseudoplatystoma corruscans, Pimelodidae) in the São Francisco river, Brazil

    USGS Publications Warehouse

    Godinho, Alexandre L.; Kynard, Boyd; Godinho, Hugo P.

    2007-01-01

    Surubim, Pseudoplatystoma corruscans, is the most valuable commercial and recreational fish in the São Francisco River, but little is known about adult migration and spawning. Movements of 24 females (9.5–29.0 kg), which were radio-tagged just downstream of Três Marias Dam (TMD) at river kilometer 2,109 and at Pirapora Rapids (PR) 129 km downstream of TMD, suggest the following conceptual model of adult female migration and spawning. The tagged surubims used only 274 km of the main stem downstream of TMD and two tributaries, the Velhas and Abaeté rivers. Migration style was dualistic with non-migratory (resident) and migratory fish. Pre-spawning females swam at ground speeds of up to 31 km day-1 in late September–December to pre-spawning staging sites located 0–11 km from the spawning ground. In the spawning season (November–March), pre-spawning females migrated back and forth from nearby pre-spawning staging sites to PR for short visits to spawn, mostly during floods. Multiple visits to the spawning site suggest surubim is a multiple spawner. Most post-spawning surubims left the spawning ground to forage elsewhere, but some stayed at the spawning site until the next spawning season. Post-spawning migrants swam up or downstream at ground speeds up to 29 km day-1 during January–March. Construction of proposed dams in the main stem and tributaries downstream of TMD will greatly reduce surubim abundance by blocking migrations and changing the river into reservoirs that eliminate riverine spawning and non-spawning habitats, and possibly, cause extirpation of populations.

  1. 18 CFR 1304.411 - Fish attractor, spawning, and habitat structures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Fish attractor, spawning, and habitat structures. 1304.411 Section 1304.411 Conservation of Power and Water Resources... STRUCTURES AND OTHER ALTERATIONS Miscellaneous § 1304.411 Fish attractor, spawning, and habitat...

  2. 18 CFR 1304.411 - Fish attractor, spawning, and habitat structures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Fish attractor, spawning, and habitat structures. 1304.411 Section 1304.411 Conservation of Power and Water Resources... STRUCTURES AND OTHER ALTERATIONS Miscellaneous § 1304.411 Fish attractor, spawning, and habitat...

  3. Spawning Distribution of Fall Chinook Salmon in the Snake River : Annual Report 1999.

    SciTech Connect

    Garcia, Aaron P.

    2000-04-01

    This report is separated into 2 chapters. The chapters are (1) Progress toward determining the spawning distribution of supplemented fall chinook salmon in the Snake River in 1999; and (2) Fall chinook salmon spawning ground surveys in the Snake River, 1999.

  4. 18 CFR 1304.411 - Fish attractor, spawning, and habitat structures.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Fish attractor, spawning, and habitat structures. 1304.411 Section 1304.411 Conservation of Power and Water Resources... STRUCTURES AND OTHER ALTERATIONS Miscellaneous § 1304.411 Fish attractor, spawning, and habitat...

  5. 18 CFR 1304.411 - Fish attractor, spawning, and habitat structures.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Fish attractor, spawning, and habitat structures. 1304.411 Section 1304.411 Conservation of Power and Water Resources... STRUCTURES AND OTHER ALTERATIONS Miscellaneous § 1304.411 Fish attractor, spawning, and habitat...

  6. 18 CFR 1304.411 - Fish attractor, spawning, and habitat structures.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Fish attractor, spawning, and habitat structures. 1304.411 Section 1304.411 Conservation of Power and Water Resources TENNESSEE... OTHER ALTERATIONS Miscellaneous § 1304.411 Fish attractor, spawning, and habitat structures....

  7. Deschutes River Spawning Gravel Study, Volume II, Appendices I-XIV, Final Report.

    SciTech Connect

    Huntington, Charles W.

    1985-09-01

    Spawning habitat in the Deschutes River was inventoried, gravel permeability and composition were sampled at selected gravel bars, historical flow records for the Deschutes were analyzed, salmon and trout utilization of spawning habitat was examined, and potential methods of enhancing spawning habitat in the river were explored. Some changes in river conditions since the mid-1960's were identified, including a reduction in spawning habitat immediately downstream from the hydroelectric complex. The 1964 flood was identified as a factor which profoundly affected spawning habitat in the river, and which greatly complicated efforts to identify recent changes which could be attributed to the hydrocomplex. A baseline on present gravel quality at both chinook and steelhead spawning areas in the river was established using a freeze-core methodology. Recommendations are made for enhancing spawning habitat in the Deschutes River, if it is independently determined that spawning habitat is presently limiting populations of summer steelhead or fall chinook in the river. Volume II contains appendices to the study.

  8. Use of ELISA to monitor bacterial kidney disease in naturally spawning chinook salmon.

    PubMed

    O'Connor, Glenda; Hoffnagle, Timothy L

    2007-09-14

    Bacterial kidney disease (BKD) caused by Renibacterium salmoninarum (Rs) is a serious problem among Pacific Northwest salmon hatcheries and has raised concerns that salmon reared in hatcheries may spread BKD to natural populations. In order to monitor the potential spread of this disease to salmon spawning in nature, a method must be available to collect and analyze tissues from naturally spawning salmon. Kidney tissue analyzed by enzyme-linked immunosorbent assay (ELISA) is the standard method to detect the presence of Rs in salmon sampled in hatcheries. In this study, we tested the validity of using ELISA on kidney tissue collected from intact carcasses recovered on the spawning grounds to monitor BKD in naturally spawning populations by comparing ELISA optical density (OD) values from kidney tissue that was subjected to conditions that simulated decomposition in a carcass and collection during a spawning ground survey with samples freshly collected from salmon at a hatchery. Mean ELISA OD levels were 1.060 for the samples prepared by the normal preparation and 1.115 for samples prepared by simulating spawning ground survey collection. There was no significant difference in mean ELISA OD between the 2 sample preparations and the relationship did not significantly differ from 1:1 (slope = 0.946). This demonstrates that BKD prevalence in natural populations can be monitored using ELISA conducted on samples from intact carcasses recovered on spawning ground surveys. This will be an important tool for monitoring the effect of hatchery supplementation on naturally spawning salmon populations. PMID:17972755

  9. Bear use of cutthroat trout spawning streams in Yellowstone National Park

    USGS Publications Warehouse

    Reinhart, D.P.; Mattson, D.J.

    1990-01-01

    Grizzly bears (Ursus arctos) and black bears (U. americanus) prey on spawning cutthroat trout (Oncorhynchus clarki, formerly known as Salmo clarki) in tributary streams of Yellowstone Lake. These tributary streams were surveyed from 1985 to 1987 to determine the presence and level of trout spawning activity and bear use. Indices were developed to enumerate spawner density and levels of bear use. Of 124 known tributaries of Yellowstone Lake, 48% had a spawning run. Of these spawning streams, 93% had associated bear activity, and 61% had associated evidence of bear fishing. Bears were apparently using more spawning streams and fish compared to 10 years earlier. Bear use of cutthroat trout spawning streams appeared to be largely a positive function of volumetric spawner density. We hypothesize that abundance and quality of stream-side vegetation relative to other foraging options influenced bear use. Intra- and interspecific avoidance among bears was suggested by patterns of spawning stream use. Less bear use of spawning streams than expected occurred within 1 km of park developments.

  10. Spawning, copulation and inbreeding coefficients in marine invertebrates.

    PubMed

    Addison, J A; Hart, M W

    2005-12-22

    Patterns of population genetic variation have frequently been understood as consequences of life history covariates such as dispersal ability and breeding systems (e.g. selfing). For example, marine invertebrates show enormous variation in life history traits that are correlated with the extent of gene flow between populations and the magnitude of differentiation among populations at neutral genetic markers (FST). Here we document an unexpected correlation between marine invertebrate life histories and deviation from Hardy-Weinberg equilibrium (non-zero values of FIS, the inbreeding coefficient). FIS values were significantly higher in studies of species with free-spawned planktonic sperm than in studies of species that copulate or have some form of direct sperm transfer to females or benthic egg masses. This result was robust to several different analytical approaches. We note several mechanisms that might contribute to this pattern, and appeal for more studies and ideas that might help to explain our observations. PMID:17148230

  11. Spawning behaviour of Allis shad Alosa alosa: new insights based on imaging sonar data.

    PubMed

    Langkau, M C; Clavé, D; Schmidt, M B; Borcherding, J

    2016-06-01

    Spawning behaviour of Alosa alosa was observed by high resolution imaging sonar. Detected clouds of sexual products and micro bubbles served as a potential indicator of spawning activity. Peak spawning time was between 0130 and 0200 hours at night. Increasing detections over three consecutive nights were consistent with sounds of mating events (bulls) assessed in hearing surveys in parallel to the hydro acoustic detection. In 70% of the analysed mating events there were no additional A. alosa joining the event whilst 70% of the mating events showed one or two A. alosa leaving the cloud. In 31% of the analysed mating events, however, three or more A. alosa were leaving the clouds, indicating that matings are not restricted to a pair. Imaging sonar is suitable for monitoring spawning activity and behaviour of anadromous clupeids in their spawning habitats. PMID:27126879

  12. Quality assessment of wild Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) semen under conditions of short-term storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Short-term storage trials were conducted with Atlantic sturgeon semen collected from a total of nine wild males during the 2008 and 2009 spawning seasons on the Hudson River. Semen samples were kept refrigerated (4 plus or minus 1 degree C) and stored in different gaseous atmospheres and storage ext...

  13. Characterization of channel substrate, and changes in suspended-sediment transport and channel geometry in white sturgeon spawning habitat in the Kootenai River near Bonners Ferry, Idaho, following the closure of Libby Dam

    USGS Publications Warehouse

    Barton, Gary J.

    2004-01-01

    Many local, State, and Federal agencies have concerns over the declining population of white sturgeon (Acipenser transmontanus) in the Kootenai River and the possible effects of the closure and subsequent operation of Libby Dam in 1972. In 1994, the Kootenai River white sturgeon was listed as an Endangered Species. A year-long field study was conducted in cooperation with the Kootenai Tribe of Idaho along a 21.7-kilometer reach of the Kootenai River including the white sturgeon spawning reach near Bonners Ferry, Idaho, approximately 111 to 129 kilometers below Libby Dam. During the field study, data were collected in order to map the channel substrate in the white sturgeon spawning reach. These data include seismic subbottom profiles at 18 cross sections of the river and sediment cores taken at or near the seismic cross sections. The effect that Libby Dam has on the Kootenai River white sturgeon spawning substrate was analyzed in terms of changes in suspended-sediment transport, aggradation and degradation of channel bed, and changes in the particle size of bed material with depth below the riverbed. The annual suspended-sediment load leaving the Kootenai River white sturgeon spawning reach decreased dramatically after the closure of Libby Dam in 1972: mean annual pre-Libby Dam load during 1966–71 was 1,743,900 metric tons, and the dam-era load during 1973–83 was 287,500 metric tons. The amount of sand-size particles in three suspended-sediment samples collected at Copeland, Idaho, 159 kilometers below Libby Dam, during spring and early summer high flows after the closure of Libby Dam is less than in four samples collected during the pre-Libby Dam era. The supply of sand to the spawning reach is currently less due to the reduction of high flows and a loss of 70 percent of the basin after the closure of Libby Dam. The river's reduced capacity to transport sand out of the spawning reach is compensated to an unknown extent by a reduced load of sand entering the

  14. Patterns of migration between feeding and spawning sites in a coral reef surgeonfish

    NASA Astrophysics Data System (ADS)

    Claydon, J. A. B.; McCormick, M. I.; Jones, G. P.

    2012-03-01

    Many coral reef fishes exhibit regular localised migrations between feeding and spawning areas, but the factors affecting these migration patterns, such as the distance, frequency and spawning site fidelity are poorly understood. The aim of this study was to investigate the patterns of migration to spawning sites of the surgeonfish, Ctenochaetus striatus (Acanthuridae). We explored relationships amongst an individual's size and sex, the distance and frequency it migrated from its feeding area to spawning sites, fidelity to particular spawning sites and the number of individuals that aggregated to spawn. In order to achieve this, 406 C. striatus were captured and tagged on inshore reefs in Kimbe Bay (5°30'S 150°6'E), New Britain, Papua New Guinea. Tagged individuals were consistently observed within spatially discrete but overlapping feeding areas (maximum diameter averaging <13 m). The mean distance migrated was 58 m (ranging from 2 to 291 m). No tagged individuals were witnessed spawning at more than one site. Whilst most individuals ( n = 88) migrated to the spawning site that was closest to their feeding areas, those that migrated to sites further away ( n = 9) always spawned at sites where the number of conspecifics aggregating was larger. Neither the size nor the sex of individuals limited migration distance. However, males migrated significantly more frequently than females (on average once every 2 days vs. once every 3 days), and migration frequency was positively correlated with size in females. Migration distance did not affect the frequency with which individuals spawned. Whether patterns of migration are determined by cost-benefit optimisation, tradition, or an alternative mechanism is unknown.

  15. Predicting crappie recruitment in Ohio reservoirs with spawning stock size, larval density, and chlorophyll concentrations

    USGS Publications Warehouse

    Bunnell, David B.; Hale, R. Scott; Vanni, Michael J.; Stein, Roy A.

    2006-01-01

    Stock-recruit models typically use only spawning stock size as a predictor of recruitment to a fishery. In this paper, however, we used spawning stock size as well as larval density and key environmental variables to predict recruitment of white crappies Pomoxis annularis and black crappies P. nigromaculatus, a genus notorious for variable recruitment. We sampled adults and recruits from 11 Ohio reservoirs and larvae from 9 reservoirs during 1998-2001. We sampled chlorophyll as an index of reservoir productivity and obtained daily estimates of water elevation to determine the impact of hydrology on recruitment. Akaike's information criterion (AIC) revealed that Ricker and Beverton-Holt stock-recruit models that included chlorophyll best explained the variation in larval density and age-2 recruits. Specifically, spawning stock catch per effort (CPE) and chlorophyll explained 63-64% of the variation in larval density. In turn, larval density and chlorophyll explained 43-49% of the variation in age-2 recruit CPE. Finally, spawning stock CPE and chlorophyll were the best predictors of recruit CPE (i.e., 74-86%). Although larval density and recruitment increased with chlorophyll, neither was related to seasonal water elevation. Also, the AIC generally did not distinguish between Ricker and Beverton-Holt models. From these relationships, we concluded that crappie recruitment can be limited by spawning stock CPE and larval production when spawning stock sizes are low (i.e., CPE , 5 crappies/net-night). At higher levels of spawning stock sizes, spawning stock CPE and recruitment were less clearly related. To predict recruitment in Ohio reservoirs, managers should assess spawning stock CPE with trap nets and estimate chlorophyll concentrations. To increase crappie recruitment in reservoirs where recruitment is consistently poor, managers should use regulations to increase spawning stock size, which, in turn, should increase larval production and recruits to the fishery.

  16. Spawning Distribution of Fall Chinook Salmon in the Snake River : Annual Report 2000.

    SciTech Connect

    Garcia, Aaron P.

    2001-08-01

    From 1997 to 2000, we collected data on the spawning distribution of fall chinook salmon above Lower Granite Dam as part of a five-year evaluation of three acclimation/release facilities: Pittsburgh Landing, Captain John, and Big Canyon Creek. The use of multiple facilities is intended to distribute spawning throughout the habitat normally used in the Snake and Clearwater rivers, and our study was designed to determine if this is achieved. In the Snake River, spawning normally occurs throughout a 100 mile reach. Pittsburgh Landing is located within the upper half of this reach, and Captain John is located within the lower half. In the Clearwater River, most spawning occurs within the lower 41 miles and the Big Canyon Creek facility is located therein. Our approach for determining spawning distribution was to first trap returning fish at Lower Granite Dam, identify their origin (all yearling fish were externally marked before they were released), and use radio tags and redd searches to determine where they spawned. Thus far we radio tagged 203 adult fish that were initially released at the acclimation sites. We confirmed the spawning location of 74 of these fish, 42 from releases at Pittsburgh Landing, seven from Captain John, and 25 from releases at the Big Canyon Creek facility. All of the fish from Pittsburgh Landing spawned in the Snake River, 86% within the upper half of the Snake River study area, and 14% in the lower half. Of the adult fish from Captain John, roughly 71% spawned in the lower half of the Snake River study area, 14% spawned in the upper half, and 14% spawned in the Clearwater River. Of the adult fish from releases at Big Canyon Creek, 80% spawned in the Clearwater River and 20% spawned in the Snake River (four in the lower half and one in the upper half). To augment the study, we determined the spawning locations of 16 adult fish that were directly released as subyearlings at or near the three acclimation sites. Ten of the fish were from

  17. Deepwater Spawning of Fall Chinook Salmon (Oncorhynchus Tshawytscha) : Spawning Near Ives and Pierce Island of the Columbia River, 2001 Annual Report.

    SciTech Connect

    Mueller, Robert P.

    2002-10-01

    Pacific Northwest National Laboratory initiated studies to identify potential fall chinook salmon (Oncorhynchus tshawytscha) spawning habitat and assess the extent of spawning in deep water (>1 m) downstream of Bonneville Dam in the fall of 1999. This report provides results from 2001, the third year of our effort. The main objective of this study was to find deepwater spawning locations of fall chinook salmon in the main Columbia River channel, collect additional data on physical habitat parameters at spawning sites, and provide estimates of adult spawners in the area. The secondary objective was to map any chum salmon redds located in the deeper sections near Hamilton Slough. River flows during the spawning surveys in 2001 were lower than in 1999 and 2000. Peak spawning activity, based on redd counts and live fish seen near redds, was on or near November 9, 2001. The location of the spawning area was similar to that of 1999 and 2000. One difference was the majority of redds were found in deeper water (>1.5 m) and closer to the shoreline adjacent to Pierce Island. Because of the low river flows during the fall of 2001, only a handful of redds were found using the boat-deployed video system within Hamilton Slough. No chum salmon (O. keta) redds were found in areas surveyed during 2000. (Note: surveys were limited to deeper sections of Hamilton Slough and near the main river channel.) An estimated 717 fall chinook salmon redds at water depths exceeding 1.5 m ({approx} 125 kcfs) were documented in 2001. These estimates are expanded from the number of redds found within a predefined survey area. Fall chinook salmon redds were found at water depths from 1.5-4.6 m and were located in a general area of {approx} 4.9 ha. Fall chinook salmon redds were constructed in gravels ranging from 3.2-13.4 cm in diameter and water velocities of 0.29-0.70 m/s.

  18. Induced nest spawning and artificial hatching of the fertilized eggs of mudskipper, Boleophthalmus pectinirostris

    NASA Astrophysics Data System (ADS)

    Hong, Wanshu; Zhang, Qiyong

    2004-12-01

    In this study, nest spawning was successfully induced by exogenous hormone injections and seawater flow stimulation, and optimum condition for hatching fertilized eggs of burrow fish mudskipper, Boleophthalmus pectinirostris, was searched. Apart from spawning inside the nests, females also spawned outside the nests. The percentages of spawned nests were 8.0% to 24.2%. Most eggs were observed adhered to the inner wall of the top half of the nest. Fertilization rates of the nest-spawned eggs varied from 17.3% to 80.8%. Females could spawn after being artificially confined inside the nests with males at ratios of 1∶1 or 1∶2, but the spawned eggs were not fertilized. Mean hatching rates of artificially fertilized eggs incubated in round plastic buckets were 32.7% 70.6%, and in the net cages, were 4.2% 20.5%, respectively. Mean hatching rates of nest-fertilized eggs incubated in the round plastic buckets were 33.6% 76.3%, and in the net cages, were 5.9% 25.2%. Results showed that round bucket incubation was the best way for hatching fertilized eggs of mudskipper. Keeping the hatching seawater flowing is an important way for increasing the hatching rates of the mudskipper fertilized eggs.

  19. Laboratory observation on spawning, fecundity and larval development of amphioxus ( Branchiostoma belcheri Tsingtaunese)

    NASA Astrophysics Data System (ADS)

    Wu, Xian-Han; Zhang, Shi-Cui; Wang, Yong-Yuan; Zhang, Bao-Lu; Qu, Yan-Mei; Jiang, Xin-Ji

    1994-12-01

    Although amphioxus is widespread in temperate and tropical seas, its population is diminishing because of environmental pollution. To keep the population of this evolutionarily important animal from diminishing, study on its reproduction and development is necessary. The main findings in this study on the spawning and fecundity of the amphioxus reared in laboratory and its larval development are as follows. 1. Water temperature markedly affected the spawning. It spawned only when water temperature reached 21°C. 2. Spawning of the amphioxus in laboratory was markedly extended. Initially, the amphioxus spawned at about 7:00 PM, but spawning time was postponed as spawning days went on. 3. The number of eggs produced by a female ranged from 1400 to 12800, average of 5800. This also represents the fecundity of the amphioxus because it shedded all eggs within the ovary at a time. 4. During the first few months of life of the amphioxus, its growth rate changed seasonally. The growth rate in summer and fall was greater than that in winter. 5. The pelagic larva became a benthic adult after 50 days. 6. The amphioxus reared in laboratory from fertilized eggs could produce fertile eggs and sperms. These findings can be a foundation for measures to address the problem of diminishing amphioxus population.

  20. Spawning related movement of shovelnose sturgeon in the Missouri River above Fort Peck Reservoir, Montana

    USGS Publications Warehouse

    Richards, Ryan R.; Guy, Christopher S.; Webb, Molly A.; Gardner, William M.; Jensen, C.B.

    2014-01-01

    The hypotheses of this study were (i) that shovelnose sturgeon would make upstream movements to spawn, (ii) movement of spawning fish would be greater in a year with higher discharge, and (iii) that spawning fish would have greater movements than reproductively inactive fish. Shovelnose sturgeon Scaphirhynchus platorynchus (Rafinesque, 1820) in five reproductive categories (e.g. males, confirmed spawning females, potentially spawning females, atretic females, and reproductively inactive females) were tracked in 2008 and 2009. All reproductive categories, except reproductively inactive females, exhibited large-scale movements and had omnidirectional movements. No differences in movement rates were observed in confirmed spawning females between years despite a 45% higher peak discharge in 2008 (839 m3 s−1) than in 2009 (578 m3 s−1). A peak discharge was obtained at a faster rate in 2008 (165 m3 s−1 day−1) than in 2009 (39 m3 s−1 day−1), and high discharge was of greater duration in 2008. Reproductively inactive females did not exhibit large-scale movements and their movement rate differed from other reproductive categories. Shovelnose sturgeon spawned in both years, despite highly varying hydrographs between years.

  1. Not All Offspring Are Created Equal: Variation in Larval Characteristics in a Serially Spawning Damselfish

    PubMed Central

    Maddams, Jessica Claire; McCormick, Mark Ian

    2012-01-01

    The way organisms allocate their resources to growth and reproduction are key attributes differentiating life histories. Many organisms spawn multiple times in a breeding season, but few studies have investigated the impact of serial spawning on reproductive allocation. This study investigated whether resource allocation was influenced by parental characteristics and prior spawning history in a serial spawning tropical damselfish (Pomacentrus amboinensis). The offspring attributes of isolated parents of known characteristics were monitored over a 6-week breeding period in the field. Smaller females produced larvae of longer length and larger energy reserves at hatching. This finding is contrary to several other studies that found larger females produce offspring of greater quality. We found that resource allocation in the form of reproductive output was not influenced by the number of spawning events within the breeding season, with larger females producing the greatest number of offspring. Larval characteristics changed as spawning progressed. There was a general decline in length of larvae produced, with an increase in the size of the larval yolk-sac, for all females regardless of size as spawning progressed. This trend was accentuated by the smallest females. This change in larval characteristics may reflect a parental ability to forecast unfavourable conditions as the season progresses or a mechanism to ensure that some will survive no matter what conditions they encounter. This study highlights the importance of accounting for temporal changes in reproductive allocation in studies of reproductive trade-offs and investigations into the importance of parental effects. PMID:23155389

  2. Distribution and spawning dynamics of capelin (Mallotus villosus) in Glacier Bay, Alaska: A cold water refugium

    USGS Publications Warehouse

    Arimitsu, M.L.; Piatt, J.F.; Litzow, M.A.; Abookire, A.A.; Romano, Marc D.; Robards, M.D.

    2008-01-01

    Pacific capelin (Mallotus villosus) populations declined dramatically in the Northeastern Pacific following ocean warming after the regime shift of 1977, but little is known about the cause of the decline or the functional relationships between capelin and their environment. We assessed the distribution and abundance of spawning, non-spawning adult and larval capelin in Glacier Bay, an estuarine fjord system in southeastern Alaska. We used principal components analysis to analyze midwater trawl and beach seine data collected between 1999 and 2004 with respect to oceanographic data and other measures of physical habitat including proximity to tidewater glaciers and potential spawning habitat. Both spawning and non-spawning adult Pacific capelin were more likely to occur in areas closest to tidewater glaciers, and those areas were distinguished by lower temperature, higher turbidity, higher dissolved oxygen and lower chlorophyll a levels when compared with other areas of the bay. The distribution of larval Pacific capelin was not sensitive to glacial influence. Pre-spawning females collected farther from tidewater glaciers were at a lower maturity state than those sampled closer to tidewater glaciers, and the geographic variation in the onset of spawning is likely the result of differences in the marine habitat among sub-areas of Glacier Bay. Proximity to cold water in Glacier Bay may have provided a refuge for capelin during the recent warm years in the Gulf of Alaska.

  3. Location and timing of Asian carp spawning in the Lower Missouri River

    USGS Publications Warehouse

    Deters, Joseph E.; Chapman, Duane C.; McElroy, Brandon

    2013-01-01

    We sampled for eggs of Asian carps, (bighead carp Hypophthalmichthys nobilis, silver carp H. molitrix, and grass carp Ctenopharyngodon idella) in 12 sites on the Lower Missouri River and in six tributaries from the months of May through July 2005 and May through June 2006 to examine the spatial and temporal dynamics of spawning activity. We categorized eggs into thirty developmental stages, but usually they could not be identified to species. We estimated spawning times and locations based on developmental stage, temperature dependent rate of development and water velocity. Spawning rate was higher in the daytime between 05:00 and 21:00 h than at night. Spawning was not limited to a few sites, as has been reported for the Yangtze River, where these fishes are native, but more eggs were spawned in areas of high sinuosity. We employ a sediment transport model to estimate vertical egg concentration profiles and total egg fluxes during spawning periods on the Missouri River. We did not identify substantial spawning activity within tributaries or at tributary confluences examined in this study.

  4. Impact of coral spawning on the biogeochemistry of a Hawaiian reef

    NASA Astrophysics Data System (ADS)

    Briggs, R. A.; Padilla-Gamiño, J. L.; Bidigare, R. R.; Gates, R. D.; Ruttenberg, K. C.

    2013-12-01

    We examined the impact of Montipora capitata coral spawning on local biogeochemistry in Kane'ohe Bay, Hawai'i. This event supplied labile, spawn-derived organic matter (SDOM) to the water column, triggering a cascading series of related effects on the biogeochemistry of the reef. Specifically, we measured the isotopic composition and nutrient ratios of spawning material and coral tissues, and utilized these signatures to track pathways of SDOM incorporation into this coral-dominated ecosystem. We observed: (1) shifts in the isotopic signatures of coral tissues after the spawning event, (2) rapid turnover of SDOM within the water column and enhanced deposition of POM to the sediment surface, (3) enhanced sediment efflux of NH after the spawning event that triggered a phytoplankton bloom in the overlying water, and (4) drawdown of dissolved nutrients in the water column after spawning that coincided with the occurrence of a water column phytoplankton bloom. Our results show that single-species spawning events can serve as a source of substantial nutrient input to the water column, contributing in similar ways to storm-driven river nutrient input, and with measurable impact on the biogeochemistry of the reef.

  5. Biogeochemical responses following coral mass spawning on the Great Barrier Reef: pelagic-benthic coupling

    NASA Astrophysics Data System (ADS)

    Wild, C.; Jantzen, C.; Struck, U.; Hoegh-Guldberg, O.; Huettel, M.

    2008-03-01

    This study quantified how the pulse of organic matter from the release of coral gametes triggered a chain of pelagic and benthic processes during an annual mass spawning event on the Australian Great Barrier Reef. Particulate organic matter (POM) concentrations in reef waters increased by threefold to 11-fold the day after spawning and resulted in a stimulation of pelagic oxygen consumption rates that lasted for at least 1 week. Water column microbial communities degraded the organic carbon of gametes of the broadcast-spawning coral Acropora millepora at a rate of >15% h-1, which is about three times faster than the degradation rate measured for larvae of the brooding coral Stylophora pistillata. Stable isotope signatures of POM in the water column reflected the fast transfer of organic matter from coral gametes into higher levels of the food chain, and the amount of POM reaching the seafloor immediately increased after coral spawning and then tailed-off in the next 2 weeks. Short-lasting phytoplankton blooms developed within a few days after the spawning event, indicating a prompt recycling of nutrients released through the degradation of spawning products. These data show the profound effects of coral mass spawning on the reef community and demonstrate the tight recycling of nutrients in this oligotrophic ecosystem.

  6. Response of ecosystem metabolism to low densities of spawning Chinook salmon

    USGS Publications Warehouse

    Benjamin, Joseph R.; Bellmore, James R.; Watson, Grace A.

    2016-01-01

    Marine derived nutrients delivered by large runs of returning salmon are thought to subsidize the in situ food resources that support juvenile salmon. In the Pacific Northwest, USA, salmon have declined to <10% of their historical abundance, with subsequent declines of marine derived nutrients once provided by large salmon runs. We explored whether low densities (<0.001 spawners/m2) of naturally spawning Chinook Salmon (Oncorhynchus tshawytscha) can affect ecosystem metabolism. We measured gross primary production (GPP) and ecosystem respiration (ER) continuously before, during, and after salmon spawning. We compared downstream reaches with low densities of spawning salmon to upstream reaches with fewer or no spawners in 3 mid-sized (4th-order) rivers in northern Washington. In addition, we measured chemical, physical, and biological factors that may be important in controlling rates of GPP and ER. We observed that low densities of spawning salmon can increase GPP by 46% during spawning, but values quickly return to those observed before spawning. No difference in ER was observed between up- and downstream reaches. Based on our results, salmon density, temperature, and the proximity to salmon redds were the most important factors controlling rates of GPP, whereas temperature was most important for ER. These results suggest that even at low spawning densities, salmon can stimulate basal resources that may propagate up the food web. Understanding how recipient ecosystems respond to low levels of marine derived nutrients may inform nutrient augmentation studies aimed at enhancing fish populations.

  7. Spawning aggregations of three protogynous groupers in the southern Gulf of Mexico.

    PubMed

    Tuz-Sulub, A; Brulé, T

    2015-01-01

    Spawning aggregations of red hind Epinephelus guttatus, tiger grouper Mycteroperca tigris and yellowfin grouper Mycteroperca venenosa were identified at two coral-reef systems: Arrecife Alacranes (emergent bank reef) and Bajos del Norte (submerged bank reef) on the continental shelf of the Yucatan Peninsula (Campeche Bank), Mexico. At both reefs, E. guttatus forms large spawning aggregations between February and March. At Bajos del Norte, M. tigris reproduces in a small, low-density aggregation in May, while M. venenosa aggregates at high densities for spawning between March and May. Multi-species use of an aggregation site by E. guttatus and M. venenosa was observed at Bajos del Norte. The identified spawning aggregations are apparently stable in location over time, and all three species were commonly observed to spawn within 1 week following the full moon. Development and survival of the larvae spawned in these aggregations are probably aided by a seasonal (spring-summer) upwelling in the north-east Campeche Bank. A permanent area closure at Bajos del Norte, currently outside any specific fisheries management area or regulations, would provide protection needed for the spawning aggregations of these three species. PMID:25557429

  8. First record of multi-species synchronous coral spawning from Malaysia.

    PubMed

    Chelliah, Alvin; Amar, Halimi Bin; Hyde, Julian; Yewdall, Katie; Steinberg, Peter D; Guest, James R

    2015-01-01

    Knowledge about the timing and synchrony of coral spawning has important implications for both the ecology and management of coral reef ecosystems. Data on the timing of spawning and extent of synchrony, however, are still lacking for many coral reefs, particularly from equatorial regions and from locations within the coral triangle. Here we present the first documentation of a multi-species coral spawning event from reefs around Pulau Tioman, Peninsular Malaysia, a popular diving and tourist destination located on the edge of the coral triangle. At least 8 coral species from 3 genera (Acropora, Montipora and Porites) participated in multi-species spawning over five nights in April 2014, between two nights before and two nights after the full moon. In addition, two Acropora species were witnessed spawning one night prior to the full moon in October 2014. While two of the Acropora species that reproduced in April (A. millepora and A. nasuta) exhibited highly synchronous spawning (100% of sampled colonies), two other common species (A. hyacinthus and A. digitifera) did not contain visible eggs in the majority of colonies sampled (i.e., <15% of colonies) in either April or October, suggesting that these species spawn at other times of the year. To the best of our knowledge, this is the first detailed documented observation of multi-species coral spawning from reefs in Malaysia. These data provide further support for the contention that this phenomenon is a feature of all speciose coral assemblages, including equatorial reefs. More research is needed, however, to determine the seasonal cycles and extent of spawning synchrony on these reefs and elsewhere in Malaysia. PMID:25737817

  9. Potential spawn induction and suppression agents in Caribbean Acropora cervicornis corals of the Florida Keys

    PubMed Central

    Than, John T.

    2016-01-01

    The enhanced ability to direct sexual reproduction may lead to improved restoration outcomes for Acropora cervicornis. Gravid fragments of A. cervicornis were maintained in a laboratory for two sequential trials in the seven days prior to natural spawning in the Florida Keys. Ten replicates of five chemicals known to affect spawning in various invertebrate taxa were tested. Hydrogen peroxide at 2 mM (70%) and L-5-hydroxytryptophan (5-HTP) at 5 (40%) and 20 µM (30%) induced spawning within 15.4 h, 38.8 h and 26.9 h of dosing at or above the rate of release of the control (30%) within 14.6 h. Serotonin acetate monohydrate at 1 µM (20%) and 10 µM (20%), naloxone hydrochloride dihydrate at 0.01 µM (10%) and potassium phosphate monobasic at 0.25 µM (0%) induced spawning at rates less than the control. Although the greatest number of fragments spawned using hydrogen peroxide, it was with 100% mortality. There was a significantly higher induction rate closer to natural spawn (Trial 2) compared with Trial 1 and no genotype effect. Mechanisms of action causing gamete release were not elucidated. In Caribbean staghorn corals, 5-HTP shows promise as a spawning induction agent if administered within 72 h of natural spawn and it will not result in excessive mortality. Phosphate chemicals may inhibit spawning. This is the first study of its kind on Caribbean acroporid corals and may offer an important conservation tool for biologists currently charged with restoring the imperiled Acropora reefs of the Florida Keys. PMID:27168990

  10. Potential spawn induction and suppression agents in Caribbean Acropora cervicornis corals of the Florida Keys.

    PubMed

    Flint, Mark; Than, John T

    2016-01-01

    The enhanced ability to direct sexual reproduction may lead to improved restoration outcomes for Acropora cervicornis. Gravid fragments of A. cervicornis were maintained in a laboratory for two sequential trials in the seven days prior to natural spawning in the Florida Keys. Ten replicates of five chemicals known to affect spawning in various invertebrate taxa were tested. Hydrogen peroxide at 2 mM (70%) and L-5-hydroxytryptophan (5-HTP) at 5 (40%) and 20 µM (30%) induced spawning within 15.4 h, 38.8 h and 26.9 h of dosing at or above the rate of release of the control (30%) within 14.6 h. Serotonin acetate monohydrate at 1 µM (20%) and 10 µM (20%), naloxone hydrochloride dihydrate at 0.01 µM (10%) and potassium phosphate monobasic at 0.25 µM (0%) induced spawning at rates less than the control. Although the greatest number of fragments spawned using hydrogen peroxide, it was with 100% mortality. There was a significantly higher induction rate closer to natural spawn (Trial 2) compared with Trial 1 and no genotype effect. Mechanisms of action causing gamete release were not elucidated. In Caribbean staghorn corals, 5-HTP shows promise as a spawning induction agent if administered within 72 h of natural spawn and it will not result in excessive mortality. Phosphate chemicals may inhibit spawning. This is the first study of its kind on Caribbean acroporid corals and may offer an important conservation tool for biologists currently charged with restoring the imperiled Acropora reefs of the Florida Keys. PMID:27168990

  11. Endocrine events associated with spawning behavior in the sea lamprey (Petromyzon marinus)

    USGS Publications Warehouse

    Linville, Jane E.; Hanson, Lee H.; Sower, Stacia A.

    1987-01-01

    Levels of estradiol, progesterone, and testosterone were determined in plasma of sea lamprey (Petromyzon marinus) undergoing certain behaviors associated with spawning in natural and artifical stream environments. Significantly higher levels of estradiol, progesterone, and testosterone were found in males than in females. In the artifical spawning channel, levels of estradiol were significantly higher in females exhibiting resting and swimming behaviors than in fanning, nest building, and spawning behaviors. No significant correlation was found with either progesterone or testosterone levels and the various reproductive behaviors. The data presented are the first experimental evidence that suggest gonadal steroids may be correlated with certain reproductive behaviors in the sea lamprey.

  12. Influence of Glutamine Supplementation on Motility and Fertilization Success of Frozen-Thawed Persian Sturgeon (Acipenser persicus) Sperm.

    PubMed

    Aramli, M S; Golshahi, K; Nazari, R M; Golpour, A; Aramli, S

    2016-08-01

    Amino acids have an important biological role for the prevention of cell damage during cryopreservation. The aim of this study was to investigate the effects of glutamine on post-thaw sperm motility and fertilization success in the Persian sturgeon (Acipenser persicus). Sperm collected from six fish was cryopreserved in extenders containing different glutamine concentrations (2.5, 5 and 10 mm). Sperm samples diluted at the ratio of 1 : 1 using the extenders were subjected to cryopreservation. After dilution, the sperm suspensions were sucked into 250-μl straws; the straws were placed on the tray, frozen in nitrogen vapour and plunged into liquid nitrogen. Then, sperm were thawed in a water bath at 40°C for 5 s and used for analysis. Our results revealed that an increase in the concentration of glutamine caused a significant increase in the motility percentage, curvilinear velocity (VCL) and also fertilization success in the Persian sturgeon (p < 0.05). Comparing all concentrations of glutamine, the best concentration for sperm motility and fertilization rate was 10 mm. In addition, higher post-thaw motility percentage, VCL, and fertilization and hatching rates were obtained with the extender at the concentration of 10 mm (p < 0.05). The findings of this study showed that glutamine was of greater benefit to Persian sturgeon sperm motility during frozen-thawed process. PMID:27168189

  13. Mycobacterium chelonae associated with tumor-like skin and oral masses in farmed Russian sturgeons (Acipenser gueldenstaedtii)

    PubMed Central

    2014-01-01

    Background Non-tuberculous mycobacteria responsible for piscine mycobacteriosis usually produce visceral granulomas in both freshwater and marine species. In this study, the first occurrence of Mycobacterium chelonae associated with tumor-like lesions in the Russian sturgeon (Acipenser gueldenstaedtii) is reported. Fifteen sturgeons from an Italian fish farm showing skin and oral cauliflower-like masses were investigated by histopathology, bacterial culture and molecular analyses. Results A total of 20 masses different in size located in the mouth and in pectoral and caudal fins (characterized by abundant calcium deposits and by mild to moderate granulomatous inflammation) were observed with a significant different degree of histological severity. All internal organs of the fish were negative for mycobacteria, Ziehl-Neelsen was positive in only one of the oral masses, whereas bacterial and PCR analyses detected the presence of M. chelonae for almost all the skin and oral masses. Based on these results, a calcinosis of dystrophic origin associated with a chronic granulomatous inflammation was considered as a primary diagnosis consequent to tissue injury in areas susceptible to trauma. Conclusions We hypothesized that the occurrence of M. chelonae in farmed sturgeons was only a secondary event related to its presence in a stressful rearing environment and subsequent to a dystrophic calcinosis occurred in previously damaged tissues. PMID:24423126

  14. Current Occurrence of the Atlantic Sturgeon Acipenser oxyrinchus in Northern Spain: A New Prospect for Sturgeon Conservation in Western Europe

    PubMed Central

    Elvira, Benigno

    2015-01-01

    Acipenser oxyrinchus is considered extirpated in Europe, but numerous breeding populations still exist on the Atlantic coast of North America. An adult female A. oxyrinchus, 2500 mm total length and 120 kg wet weight, was accidentally fished on 24 November 2010 near the coast of Gijón, Asturias, Spain. The fish was identified by its morphological pattern as well as by mitochondrial and nuclear DNA analyses. Because the sturgeon was found far away from any known breeding area, it was considered a stray or vagrant specimen. It certainly has a natural origin, but its eventual birthplace could not be determined. Because its current occurrence was unknown in southwestern Europe until now, the species is not cataloged or protected in this area. Therefore, the residual European stocks of A. oxyrinchus ought to be listed as Critically Endangered (CR) according to the IUCN categories. Likewise, it is imperative for southwestern European countries with an historic or recent occurrence of A. oxyrinchus to protect the species through domestic and international legislation. The present sympatric occurrence of A. sturio and A. oxyrinchus raises new challenges about key questions, such as the species selection for restoration program in European countries. Accurate monitoring is mandatory to obtain appropriate information for an assessment of the current occurrence of A. oxyrinchus in southwestern Europe. PMID:26717564

  15. Monitoring the effects of storage in caviar from farmed Acipenser transmontanus using chemical, SEM, and NMR methods.

    PubMed

    Gussoni, Maristella; Greco, Fulvia; Vezzoli, Alessandra; Paleari, Maria Antonietta; Moretti, Vittorio Maria; Beretta, Giuseppe; Caprino, Fabio; Lanza, Barbara; Zetta, Lucia

    2006-09-01

    The effects of storage at 4 degrees C on the quantity and quality of chemical components in the caviar from farmed Acipenser transmontanus have been analyzed by SEM, chemical methods, and NMR and MRI techniques. Particular attention has been focused on the lipid components, the distribution and mobility of which were strongly affected by the storage time. MRI and relaxation data indicated that lipids are endowed with two different mobility regimes, one slow (short T1) and one fast (long T1), both lengthening with the storage time. Chemical analysis assessed a total fat content that remained practically unchanged and a constant fatty acid composition during the total storage time. The combination of the two methods allowed one (a) to suppose that a mechanism of lipid hydrolysis (faster in unsalted than in salted eggs) is still occurring during storage of caviar at 4 degrees C for up to approximately 4 months and (b) to exclude that an intensive oxidative process is active in the same storage period. PMID:16939332

  16. Oxygen consumption and haematology of juvenile shortnose sturgeon Acipenser brevirostrum during an acute 24 h saltwater challenge.

    PubMed

    Penny, F M; Kieffer, J D

    2014-04-01

    This study focused on the acute physiological responses to saltwater exposure in juvenile shortnose sturgeon Acipenser brevirostrum. In two separate laboratory experiments, 2 year-old A. brevirostrum were exposed to either full (32) or half-strength (16) seawater for up to 24 h. First, oxygen consumption rates were used to estimate the metabolic costs over 24 h. Secondly, blood and muscle samples were analysed at 6, 12 and 24 h for water loss, various measures of osmoregulatory status (plasma osmolality and ions) and other standard haematological variables. Juveniles exposed to full-strength seawater showed significant decreases in oxygen consumption rates during the 24 h exposure. Furthermore, seawater-exposed fish had significantly increased plasma osmolality, ions (Na(+) and Cl(-)) and a 17% decrease in total wet mass over the 24 h exposure period. To a lesser extent, increases in osmolality, ions and mass loss were observed in fish exposed to half-strength seawater but no changes to oxygen consumption. Cortisol was also significantly increased in fish exposed to full-strength seawater. While plasma protein was elevated following 24 h in full-strength seawater, haemoglobin, haematocrit and plasma glucose levels did not change with increased salinity. These results imply an inability of juvenile A. brevirostrum to regulate water and ions in full-strength seawater within 24 h. Nonetheless, no mortality occurred in any exposure, suggesting that juvenile A. brevirostrum can tolerate short periods in saline environments. PMID:24628001

  17. Dietary Administration of Lactobacillus plantarum Enhanced Growth Performance and Innate Immune Response of Siberian Sturgeon, Acipenser baerii.

    PubMed

    Pourgholam, Moheb Ali; Khara, Hossein; Safari, Reza; Sadati, Mohammad Ali Yazdani; Aramli, Mohammad Sadegh

    2016-03-01

    We investigated the effects of Lactobacillus plantarum used as a dietary supplement on the growth performance and innate immune response in juvenile Siberian sturgeon Acipenser baerii. Juvenile fish (14.6 ± 2.3 g) were fed three experimental diets prepared by supplementing a basal diet with L. plantarum at different concentrations [1 × 10(7), 1 × 10(8) and 1 × 10(9) colony-forming units (cfu) g(-1)] and a control (non-supplemented basal) diet for 8 weeks. Growth performance indices were increased in fish fed the 1 × 10(8) cfu g(-1) L. plantarum diet compared to the other groups. There was an increased innate immune response in fish fed the experimental diets. The highest levels of lysozyme activity, total immunoglobulin (IgM) and complement component 3 (C3) were observed in fish fed the diet containing L. plantarum at a concentration of 1 × 10(8) cfu g(-1), but there was no significant difference in the level of complement component 4 (C4) in fish fed the experimental diets or the control diet. The present study underlying some positive effects (growth performance and immune indices) of dietary administration of L. plantarum at a concentration of 1 × 10(8) cfu g(-1) in the Siberian sturgeon. PMID:26686864

  18. Inactivation of Listeria innocua in nisin-treated salmon (Oncorhynchus keta) and sturgeon (Acipenser transmontanus) caviar heated by radio frequency.

    PubMed

    Al-Holy, M; Ruiter, J; Lin, M; Kang, D H; Rasco, B

    2004-09-01

    Recent regulatory concerns about the presence of the pathogen Listeria monocytogenes in ready-to-eat aquatic foods such as caviar has prompted the development of postpackaging pasteurization processes. However, caviar is heat labile, and conventional pasteurization processes affect the texture, color, and flavor of these foods negatively. In this study, chum salmon (Oncorhynchus keta, 2.5% total salt) caviar or ikura and sturgeon (Acipenser transmontanus, 3.5% total salt) caviar were inoculated with three strains of Listeria innocua in stationary phase at a level of more than 10(7) CFU/g. L innocua strains were used because they exhibit an equivalent response to L monocytogenes for many physicochemical processing treatments, including heat treatment. The products were treated by immersion in 500 IU/ml nisin solution and heat processed (an 8-D process without nisin or a 4-D process with 500 IU/ml nisin) in a newly developed radio frequency (RF; 27 MHz) heating method at 60, 63, and 65 degrees C. RF heating along with nisin acted synergistically to inactivate L. innocua cells and total mesophilic microorganisms. In the RF-nisin treatment at 65 degrees C, no surviving L. innocua microbes were recovered in sturgeon caviar or ikura. The come-up times in the RF-heated product were significantly lower compared with the water bath-heated caviar at all treatment temperatures. The visual quality of the caviar products treated by RF with or without nisin was comparable to the untreated control. PMID:15453574

  19. Characterization and inhibition studies of an α-carbonic anhydrase from the endangered sturgeon species Acipenser gueldenstaedti.

    PubMed

    Kolayli, Sevgi; Karahalil, Fatma; Sahin, Huseyin; Dincer, Barbaros; Supuran, Claudiu T

    2011-12-01

    An α-carbonic anhydrase (CA, EC 4.2.1.1) was purified and characterized kinetically from erythrocytes of the sturgeon Acipenser gueldenstaedti, an endangered species. The sturgeon enzyme (AgCA) showed kinetic parameters for the CO(2) hydration reaction comparable with those of the human erythrocytes enzyme hCA II, being a highly active enzyme, whereas its esterase activity with 4-nitrophenyl acetate as substrate was lower. Sulphonamide inhibitors (acetazolamide, sulphanilamide) strongly inhibited AgCA, whereas metal ions (Ag(+), Zn(2+), Cu(2+) and Co(2+)) were weak, millimolar inhibitors. Several widely used pesticides (2,4-dichlorophenol, dithiocarbamates, parathion and carbaryl) were also assayed as inhibitors of this enzyme. The dithiocarbamates were low micromolar AgCA inhibitors (IC(50) of 16-18 μM), whereas the other pesticides inhibited the enzyme with IC(50)s in the range of 102-398 μM. The wide use of dithiocarbamate pesticides may be one of the factors enhancing the vulnerability of this sturgeon species to pollutants. PMID:21381885

  20. A Nuclear DNA Perspective on Delineating Evolutionarily Significant Lineages in Polyploids: The Case of the Endangered Shortnose Sturgeon (Acipenser brevirostrum)

    PubMed Central

    King, Tim L.; Henderson, Anne P.; Kynard, Boyd E.; Kieffer, Micah C.; Peterson, Douglas L.; Aunins, Aaron W.; Brown, Bonnie L.

    2014-01-01

    The shortnose sturgeon, Acipenser brevirostrum, oft considered a phylogenetic relic, is listed as an “endangered species threatened with extinction” in the US and “Vulnerable” on the IUCN Red List. Effective conservation of A. brevirostrum depends on understanding its diversity and evolutionary processes, yet challenges associated with the polyploid nature of its nuclear genome have heretofore limited population genetic analysis to maternally inherited haploid characters. We developed a suite of polysomic microsatellite DNA markers and characterized a sample of 561 shortnose sturgeon collected from major extant populations along the North American Atlantic coast. The 181 alleles observed at 11 loci were scored as binary loci and the data were subjected to multivariate ordination, Bayesian clustering, hierarchical partitioning of variance, and among-population distance metric tests. The methods uncovered moderately high levels of gene diversity suggesting population structuring across and within three metapopulations (Northeast, Mid-Atlantic, and Southeast) that encompass seven demographically discrete and evolutionarily distinct lineages. The predicted groups are consistent with previously described behavioral patterns, especially dispersal and migration, supporting the interpretation that A. brevirostrum exhibit adaptive differences based on watershed. Combined with results of prior genetic (mitochondrial DNA) and behavioral studies, the current work suggests that dispersal is an important factor in maintaining genetic diversity in A. brevirostrum and that the basic unit for conservation management is arguably the local population. PMID:25166503

  1. Discovery and identification of candidate sex-related genes based on transcriptome sequencing of Russian sturgeon (Acipenser gueldenstaedtii) gonads.

    PubMed

    Chen, Yadong; Xia, Yongtao; Shao, Changwei; Han, Lei; Chen, Xuejie; Yu, Mengjun; Sha, Zhenxia

    2016-07-01

    As the Russian sturgeon (Acipenser gueldenstaedtii) is an important food and is the main source of caviar, it is necessary to discover the genes associated with its sex differentiation. However, the complicated life and maturity cycles of the Russian sturgeon restrict the accurate identification of sex in early development. To generate a first look at specific sex-related genes, we sequenced the transcriptome of gonads in different development stages (1, 2, and 5 yr old stages) with next-generation RNA sequencing. We generated >60 million raw reads, and the filtered reads were assembled into 263,341 contigs, which produced 38,505 unigenes. Genes involved in signal transduction mechanisms were the most abundant, suggesting that development of sturgeon gonads is under control of signal transduction mechanisms. Differentially expressed gene analysis suggests that more genes for protein synthesis, cytochrome c oxidase subunits, and ribosomal proteins were expressed in female gonads than in male. Meanwhile, male gonads expressed more transposable element transposase, reverse transcriptase, and transposase-related genes than female. In total, 342, 782, and 7,845 genes were detected in intersex, male, and female transcriptomes, respectively. The female gonad expressed more genes than the male gonad, and more genes were involved in female gonadal development. Genes (sox9, foxl2) are differentially expressed in different sexes and may be important sex-related genes in Russian sturgeon. Sox9 genes are responsible for the development of male gonads and foxl2 for female gonads. PMID:27199458

  2. Changes of vitellogenin and Lipase in captive Sterlet sturgeon Acipenser ruthenus females during previtellogenesis to early atresia.

    PubMed

    Akhavan, Sobhan Ranay; Salati, Amir Parviz; Falahatkar, Bahram; Jalali, Seyed Amir Hossein

    2016-06-01

    Plasma chemistry, lipid metabolism and vitellogenin gene expression of captive Sterlet sturgeon Acipenser ruthenus were studied in different maturity stages. A total of 32 fish were sampled, and maturity stages were identified on the basis of histological criteria and direct observation. Females were classified to four groups: previtellogenic, vitellogenic, post-vitellogenic, and atresia. Blood, gonad and liver tissue samples were taken through non-lethal biopsy. Our results showed that plasma levels of glucose, cholesterol, triacylglycerol, high-density lipoprotein, low-density lipoprotein, very low-density lipoprotein, calcium, phosphorus, alkaline phosphatase activity, albumin and total protein increased during ovarian development and were highest at post-vitellogenic stage. The lowest amounts in atresia stage demonstrate that lipid and energy imbalance was related to reabsorption and digestion of the yolk. These results suggested that the VLDL was the main plasma lipoprotein component of Sterlet. We determined that lipoprotein lipase and hepatic lipase activity increased during vitellogenesis process which suggested the role of lipase enzymes in regulating blood lipid metabolism. RT-PCR analysis indicates that Vitellogenin (VTG) mRNA could be detected both in livers and ovaries of female Sterlet. Throughout the study, the expression level of VTG gene showed an increase both in ovaries and in livers reaching its peak at late vitellogenesis stage. This strongly indicated a relation between VTG mRNA and ovarian development. PMID:26732070

  3. Complete mitochondrial genome of the hybrid of Acipenser schrenckii (♀) × Huso dauricus (♂).

    PubMed

    Li, Sha; Guo, Wentao; Liu, Xueqing; Qu, Huantao; Guan, Min; Su, Wei

    2016-07-01

    The complete mitochondrial genome sequence of the hybrid of Acipenser schrenckii (♀) × Huso dauricus (♂) (A × H) was first determined by a PCR-based sequencing method in this study. The mitochondrial was 16 687 bp in length, including 13 protein genes, two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and one control region. All genes were encoded on the heavy strain except for ND6 and eight tRNA genes. Base composition of the heavy strain was A (29.80%), T (24.42%), C (28.94%), G (16.82%), and with A + T bias of 54.26%. Compared with the complete mitochondrial genome of the parents, results showed the hybrid sturgeon was consistent with a maternal inheritance; however, we also found ND6 and tRNA-Glu which were species-specific for the male parent H. dauricus. The complete mitochondrial genome sequence of the A × H provided an important data set for further study in mitochondrial inheritance mechanism. PMID:26122339

  4. A nuclear DNA perspective on delineating evolutionarily significant lineages in polyploids: the case of the endangered shortnose sturgeon (Acipenser brevirostrum).

    PubMed

    King, Tim L; Henderson, Anne P; Kynard, Boyd E; Kieffer, Micah C; Peterson, Douglas L; Aunins, Aaron W; Brown, Bonnie L

    2014-01-01

    The shortnose sturgeon, Acipenser brevirostrum, oft considered a phylogenetic relic, is listed as an "endangered species threatened with extinction" in the US and "Vulnerable" on the IUCN Red List. Effective conservation of A. brevirostrum depends on understanding its diversity and evolutionary processes, yet challenges associated with the polyploid nature of its nuclear genome have heretofore limited population genetic analysis to maternally inherited haploid characters. We developed a suite of polysomic microsatellite DNA markers and characterized a sample of 561 shortnose sturgeon collected from major extant populations along the North American Atlantic coast. The 181 alleles observed at 11 loci were scored as binary loci and the data were subjected to multivariate ordination, Bayesian clustering, hierarchical partitioning of variance, and among-population distance metric tests. The methods uncovered moderately high levels of gene diversity suggesting population structuring across and within three metapopulations (Northeast, Mid-Atlantic, and Southeast) that encompass seven demographically discrete and evolutionarily distinct lineages. The predicted groups are consistent with previously described behavioral patterns, especially dispersal and migration, supporting the interpretation that A. brevirostrum exhibit adaptive differences based on watershed. Combined with results of prior genetic (mitochondrial DNA) and behavioral studies, the current work suggests that dispersal is an important factor in maintaining genetic diversity in A. brevirostrum and that the basic unit for conservation management is arguably the local population. PMID:25166503

  5. Effects of dietary β-glucan on the growth and innate immune response of juvenile Persian sturgeon, Acipenser persicus.

    PubMed

    Aramli, Mohammad Sadegh; Kamangar, Behzad; Nazari, Rajab Mohammad

    2015-11-01

    The present study evaluated the effects of different levels of dietary β-glucan (MacroGard(®)) on growth performance and innate immune parameters in juvenile Persian sturgeon (Acipenser persicus). Fish (20.1 ± 0.8 g) were allocated into 12 tanks (15 fish per tank) and triplicate groups were fed a control diet or diets containing 0.1%, 0.2% and 0.3% β-glucan. After six weeks of daily feeding (3.0% body weight day(-1)), humoral innate immune parameters (serum immunoglobulin (Ig) levels, lysozyme activity and alternative complement activity (ACH50)) and growth parameters (final weight, weight gain, specific growth rate (SGR), food conversion ratio (FCR)) were examined. Innate immune responses (lysozyme activity and ACH50) were significantly higher in 0.2% and 0.3% β-glucan fed fish (P < 0.05). Similarly, elevated growth performance (final weight, SGR and FCR) was observed in fish fed 1%, 2% and 3% β-glucan compared to the control group (P < 0.05). However, dietary β-glucan had no significant effect on survival rate of fish (P > 0.05). These results indicate that β-glucan can be considered as a beneficial dietary supplement for improving the immune response and growth performance of Persian sturgeon. PMID:26453793

  6. Development of polysomic microsatellite markers for characterization of population structuring and phylogeography in the shortnose sturgeon (Acipenser brevirostrum)

    USGS Publications Warehouse

    Henderson, Anne P.; King, Tim L.

    2012-01-01

    Shortnose sturgeon Acipenser brevirostrum is an endangered polyploid fish species for which no nuclear DNA markers previously existed. To address this need, 86 polysomic loci were developed and characterized in 20 A. brevirostrum from five river systems and eight members (parents and six progeny) of a captive-bred family. All markers proved to be polymorphic, polysomic, and demonstrated direct inheritance when tested in a captive family. Eleven loci were included in a range-wide survey of 561 fish sampled from 17 geographic collections. Allelic diversity at these markers ranged from 7 to 24 alleles/locus and averaged 16.5 alleles/locus; sufficient diversity to produce unique multilocus genotypes. In the range-wide survey, a Mantel comparison of an ecological (1-Jaccard’s) and genetic (ΦPT; an analog to FST) distance metrics, identified a strong positive correlation (r = 0.98, P PT represents a viable metric for assessing genetic relatedness using this class of marker.

  7. A nuclear DNA perspective on delineating evolutionarily significant lineages in polyploids: the case of the endangered shortnose sturgeon (Acipenser brevirostrum)

    USGS Publications Warehouse

    King, Timothy L.; Henderson, Anne P.; Kynard, Boyd E.; Kieffer, Micah C.; Peterson, Douglas L.; Aunins, Aaron W.; Brown, Bonnie L.

    2014-01-01

    The shortnose sturgeon, Acipenser brevirostrum, oft considered a phylogenetic relic, is listed as an “endangered species threatened with extinction” in the US and “Vulnerable” on the IUCN Red List. Effective conservation of A. brevirostrum depends on understanding its diversity and evolutionary processes, yet challenges associated with the polyploid nature of its nuclear genome have heretofore limited population genetic analysis to maternally inherited haploid characters. We developed a suite of polysomic microsatellite DNA markers and characterized a sample of 561 shortnose sturgeon collected from major extant populations along the North American Atlantic coast. The 181 alleles observed at 11 loci were scored as binary loci and the data were subjected to multivariate ordination, Bayesian clustering, hierarchical partitioning of variance, and among-population distance metric tests. The methods uncovered moderately high levels of gene diversity suggesting population structuring across and within three metapopulations (Northeast, Mid-Atlantic, and Southeast) that encompass seven demographically discrete and evolutionarily distinct lineages. The predicted groups are consistent with previously described behavioral patterns, especially dispersal and migration, supporting the interpretation that A. brevirostrum exhibit adaptive differences based on watershed. Combined with results of prior genetic (mitochondrial DNA) and behavioral studies, the current work suggests that dispersal is an important factor in maintaining genetic diversity in A. brevirostrum and that the basic unit for conservation management is arguably the local population.

  8. Optimum swimming pathways of fish spawning migrations in rivers

    USGS Publications Warehouse

    McElroy, Brandon; DeLonay, Aaron; Jacobson, Robert

    2012-01-01

    Fishes that swim upstream in rivers to spawn must navigate complex fluvial velocity fields to arrive at their ultimate locations. One hypothesis with substantial implications is that fish traverse pathways that minimize their energy expenditure during migration. Here we present the methodological and theoretical developments necessary to test this and similar hypotheses. First, a cost function is derived for upstream migration that relates work done by a fish to swimming drag. The energetic cost scales with the cube of a fish's relative velocity integrated along its path. By normalizing to the energy requirements of holding a position in the slowest waters at the path's origin, a cost function is derived that depends only on the physical environment and not on specifics of individual fish. Then, as an example, we demonstrate the analysis of a migration pathway of a telemetrically tracked pallid sturgeon (Scaphirhynchus albus) in the Missouri River (USA). The actual pathway cost is lower than 105 random paths through the surveyed reach and is consistent with the optimization hypothesis. The implication—subject to more extensive validation—is that reproductive success in managed rivers could be increased through manipulation of reservoir releases or channel morphology to increase abundance of lower-cost migration pathways.

  9. Changes in spawning time led to the speciation of the broadcast spawning corals Acropora digitifera and the cryptic species Acropora sp. 1 with similar gamete recognition systems

    NASA Astrophysics Data System (ADS)

    Ohki, Shun; Kowalski, Radoslaw K.; Kitanobo, Seiya; Morita, Masaya

    2015-12-01

    Multi-species spawning is reported in the coral genus Acropora, but hybridization in nature rarely occurs because of the incompatibility of gametes and the timing of spawning. However, the evolutionary relationships between gamete compatibility and spawning time are obscure. Investigations of gamete compatibility in sister species that spawn at different times may provide clues to answering this question. Acropora sp. 1 has been defined as a cryptic species of Acropora digitifera, and they are morphologically similar, but spawn in different months, suggesting that they are either a cryptic species or a different species. We examined the morphology and conducted crossing experiments using cryopreserved sperm. The morphologies (branch length, branch width, and outer diameter of axial corallites) of A. digitifera and Acropora sp. 1 differed significantly. A phylogenetic tree of partial Pax- C nuclear sequences from A. digitifera and Acropora sp. 1 shows that they are monophyletic and closely related genetically, based on F ST values and P-distance. These results imply that these two species originated recently from a common ancestor. In addition, cryopreserved sperm from both A. digitifera and Acropora sp. 1 showed bidirectional inter-crossing (cryopreserved sperm of A. digitifera and eggs of Acropora sp. 1 from Sesoko: 32.1 ± 6.7 %, control-conspecific cryopreserved sperm and eggs: 46.1 ± 10.6 %; cryopreserved sperm of Acropora sp. 1 and eggs of A. digitifera from Oku: 63.3 ± 16.6 %, control: 83.6 ± 6.0 %). The results suggest that the gametes of these two species are compatible and that the pre-zygotic isolation mechanism is relaxed because their gametes do not interact. Overall, these two species should be classified as distinct species, and changes in spawning time are related to speciation in a similar gamete recognition system.

  10. Spawning ecology of flannelmouth sucker, Catostomus lattipinnis (Catostomidae), in two small tributaries of the lower Colorado river

    USGS Publications Warehouse

    Weiss, S.J.; Otis, E.O.; Maughan, O.E.

    1998-01-01

    We report the first published accounts of spawning behavior and spawning site selection of the flannelmouth sucker in two small tributaries of the lower Colorado River in the Grand Canyon, Arizona. Spawning was observed on 20 March 1992 and from 28 March to 10 April 1993 in the Paria River, and from 16 to 19 March 1993 in Bright Angel Creek. Flannelmouth suckers exhibited promiscuous spawning behavior-individual females were typically paired with two or more males for a given event and sometimes changed partners between events. Multiple egg deposits by different females sometimes occurred at one spawning site. Flannelmouth sucker selected substrates from 16 to 32 mm diameter in both streams. Spawning occurred at depths of 10 to 25 cm in the Paria River and 19 to 41 cm in Bright Angel Creek. Mean column water velocities at spawning locations ranged from 0.15 to 1.0 m sec-1 in the Paria River and from 0.23 to 0.89 m sec-1 in Bright Angel Creek. Water temperatures recorded during spawning ranged from 9 to 18??C in the Paria River and 13 to 15??C in Bright Angel Creek. Spawning flannelmouth sucker ascended 9.8 km upstream in the Paria River and 1.25 km in Bright Angel Creek. Spawning females (410-580 mm) were significantly larger than spawning males (385-530 mm) in the Paria River. The mean size of spawning fish in the Paria River was significantly smaller than the entire stock, averaged throughout the study period (380-620 mm). However, fish spawning in 1992-1993 averaged 53 mm larger than fish spawning in the same reach of the Paria River in 1981, indicating a shift in the size structure of this stock.

  11. Fall Chinook Salmon Spawning Activity Versus Daylight and Flow in the Tailrace of a Large Hydroelectric Dam

    SciTech Connect

    McMichael, Geoffrey A.; McKinstry, Craig A.; Vucelick, Jessica A.; Lukas, Joe

    2005-05-01

    We deployed an acoustic system during the fall Chinook salmon (Oncorhynchus tshawytscha) spawning season in 2001 to determine whether fall Chinook salmon spawning activity in a hydroelectric dam tailrace area was affected by daylight or river flow dynamics. The system was deployed following a randomized study design to record fall Chinook salmon spawning activity during day and night periods in two index areas downstream of Wanapum Dam on the Columbia River in Washington, USA. One index area was a deepwater spawning area located (river kilometer (rkm) 663) in 9 to 11 m of water. The other index site was a moderate depth mid-channel bar, where water depths ranged from 2.5 to 6 m. The acoustic system was used to collect spawning activity data during free-drifts in a boat through the index areas. Spawning activity was defined as digs per minute from underwater sound recordings. Fall Chinook salmon spawning activity in the Wanapum Dam tailrace was influenced by daylight and river discharge. Results showed there was a substantial amount of spawning activity occurring during both daylight and darkness. However, there was significantly more spawning activity during daylight than at night in both index areas. Spawning activity was also affected by flow. Project discharge had a pronounced non-linear effect on spawning activity. Spawning activity was generally highest at project discharges between 1,700 and 2266 m3 sec-1 in both spawning areas, with reduced activity as discharge increased to between 3,400 and 4,250 m3 sec-1. We concluded that fall Chinook salmon spawning activity in highly variable environments was affected more by flow (and velocity) than by daylight.

  12. Marked changes in neuropeptide expression accompany broadcast spawnings in the gastropod Haliotis asinina

    PubMed Central

    2012-01-01

    Introduction A huge diversity of marine species reproduce by synchronously spawning their gametes into the water column. Although this species-specific event typically occurs in a particular season, the precise time and day of spawning often can not be predicted. There is little understanding of how the environment (e.g. water temperature, day length, tidal and lunar cycle) regulates a population’s reproductive physiology to synchronise a spawning event. The Indo-Pacific tropical abalone, Haliotis asinina, has a highly predictable spawning cycle, where individuals release gametes on the evenings of spring high tides on new and full moons during the warmer half of the year. These calculable spawning events uniquely allow for the analysis of the molecular and cellular processes underlying reproduction. Here we characterise neuropeptides produced in H. asinina ganglia that are known in egg-laying molluscs to control vital aspects of reproduction. Results We demonstrate that genes encoding APGWamide, myomodulin, the putative proctolin homologue whitnin, FMRFamide, a schistosomin-like peptide (SLP), a molluscan insulin-related peptide (MIP) and a haliotid growth-associated peptide (HGAP) all are differentially expressed in the anterior ganglia during the two week spawning cycle in both male and female abalone. Each gene has a unique and sex-specific expression profile. Despite these differences, expression levels in most of the genes peak at or within 12 h of the spawning event. In contrast, lowest levels of transcript abundance typically occurs 36 h before and 24 h after spawning, with differences in peak and low expression levels being most pronounced in genes orthologous to known molluscan reproduction neuromodulators. Conclusions Exploiting the predictable semi-lunar spawning cycle of the gastropod H. asinina, we have identified a suite of evolutionarily-conserved, mollusc-specific and rapidly-evolving neuropeptides that appear to contribute to the

  13. Shovelnose sturgeon spawning in relation to varying discharge treatments in a Missouri River tributary

    USGS Publications Warehouse

    Goodman, B.J.; Guy, C.S.; Camp, S.L.; Gardner, W.M.; Kappenman, K.M.; Webb, M.A.H.

    2013-01-01

    Many lotic fish species use natural patterns of variation in discharge and temperature as spawning cues, and these natural patterns are often altered by river regulation. The effects of spring discharge and water temperature variation on the spawning of shovelnose sturgeon Scaphirhynchus platorynchus have not been well documented. From 2006 through 2009, we had the opportunity to study the effects of experimental discharge levels on shovelnose sturgeon spawning in the lower Marias River, a regulated tributary to the Missouri River in Montana. In 2006, shovelnose sturgeon spawned in the Marias River in conjunction with the ascending, peak (134 m3/s) and descending portions of the spring hydrograph and water temperatures from 16°C to 19°C. In 2008, shovelnose sturgeon spawned in conjunction with the peak (118 m3/s) and descending portions of the spring hydrograph and during a prolonged period of increased discharge (28–39 m3/s), coupled with water temperatures from 11°C to 23°C in the lower Marias River. No evidence of shovelnose sturgeon spawning was documented in the lower Marias River in 2007 or 2009 when discharge remained low (14 and 20 m3/s) despite water temperatures suitable and optimal (12°C-24°C) for shovelnose sturgeon embryo development. A similar relationship between shovelnose sturgeon spawning and discharge was observed in the Teton River. These data suggest that discharge must reach a threshold level (28 m3/s) and should be coupled with water temperatures suitable (12°C-24°C) or optimal (16°C-20°C) for shovelnose sturgeon embryo development to provide a spawning cue for shovelnose sturgeon in the lower Marias River.

  14. Froude Number is the Single Most Important Hydraulic Parameter for Salmonid Spawning Habitat.

    NASA Astrophysics Data System (ADS)

    Gillies, E.; Moir, H. J.

    2015-12-01

    Many gravel-bed rivers exhibit historic straightening or embanking, reducing river complexity and the available habitat for key species such as salmon. A defensible method for predicting salmonid spawning habitat is an important tool for anyone engaged in assessing a river restoration. Most empirical methods to predict spawning habitat use lookup tables of depth, velocity and substrate. However, natural site selection is different: salmon must pick a location where they can successfully build a redd, and where eggs have a sufficient survival rate. Also, using dimensional variables, such as depth and velocity, is problematic: spawning occurs in rivers of differing size, depth and velocity range. Non-dimensional variables have proven useful in other branches of fluid dynamics, and instream habitat is no different. Empirical river data has a high correlation between observed salmon redds and Froude number, without insight into why. Here we present a physics based model of spawning and bedform evolution, which shows that Froude number is indeed a rational choice for characterizing the bedform, substrate, and flow necessary for spawning. It is familiar for Froude to characterize surface waves, but Froude also characterizes longitudinal bedform in a mobile bed river. We postulate that these bedforms and their hydraulics perform two roles in salmonid spawning: allowing transport of clasts during redd building, and oxygenating eggs. We present an example of this Froude number and substrate based habitat characterization on a Scottish river for which we have detailed topography at several stages during river restoration and subsequent evolution of natural processes. We show changes to the channel Froude regime as a result of natural process and validate habitat predictions against redds observed during 2014 and 2015 spawning seasons, also relating this data to the Froude regime in other, nearby, rivers. We discuss the use of the Froude spectrum in providing an indicator of

  15. Genetic effects of habitat restoration in the Laurentian Great Lakes: an assessment of lake sturgeon origin and genetic diversity

    USGS Publications Warehouse

    Jamie Marie Marranca; Amy Welsh; Roseman, Edward F.

    2015-01-01

    Lake sturgeon (Acipenser fulvescens) have experienced significant habitat loss, resulting in reduced population sizes. Three artificial reefs were built in the Huron-Erie corridor in the Great Lakes to replace lost spawning habitat. Genetic data were collected to determine the source and numbers of adult lake sturgeon spawning on the reefs and to determine if the founder effect resulted in reduced genetic diversity. DNA was extracted from larval tail clips and 12 microsatellite loci were amplified. Larval genotypes were then compared to 22 previously studied spawning lake sturgeon populations in the Great Lakes to determine the source of the parental population. The effective number of breeders (Nb) was calculated for each reef cohort. The larval genotypes were then compared to the source population to determine if there were any losses in genetic diversity that are indicative of the founder effect. The St. Clair and Detroit River adult populations were found to be the source parental population for the larvae collected on all three artificial reefs. There were large numbers of contributing adults relative to the number of sampled larvae. There was no significant difference between levels of genetic diversity in the source population and larval samples from the artificial reefs; however, there is some evidence for a genetic bottleneck in the reef populations likely due to the founder effect. Habitat restoration in the Huron-Erie corridor is likely resulting in increased habitat for the large lake sturgeon population in the system and in maintenance of the population's genetic diversity.

  16. Oxygen depletion in coastal seas and the effective spawning stock biomass of an exploited fish species

    PubMed Central

    Hinrichsen, H.-H.; von Dewitz, B.; Dierking, J.; Haslob, H.; Makarchouk, A.; Petereit, C.; Voss, R.

    2016-01-01

    Environmental conditions may have previously underappreciated effects on the reproductive processes of commercially exploited fish populations, for example eastern Baltic cod, that are living at the physiological limits of their distribution. In the Baltic Sea, salinity affects neutral egg buoyancy, which is positively correlated with egg survival, as only water layers away from the oxygen consumption-dominated sea bottom contain sufficient oxygen. Egg buoyancy is positively correlated to female spawner age/size. From observations in the Baltic Sea, a field-based relationship between egg diameter and buoyancy (floating depth) could be established. Hence, based on the age structure of the spawning stock, we quantify the number of effective spawners, which are able to reproduce under ambient hydrographic conditions. For the time period 1993–2010, our results revealed large variations in the horizontal extent of spawning habitat (1000–20 000 km2) and oxygen-dependent egg survival (10–80%). The novel concept of an effective spawning stock biomass takes into account offspring that survive depending on the spawning stock age/size structure, if reproductive success is related to egg buoyancy and the extent of hypoxic areas. Effective spawning stock biomass reflected the role of environmental conditions for Baltic cod recruitment better than the spawning stock biomass alone, highlighting the importance of including environmental information in ecosystem-based management approaches. PMID:26909164

  17. Sex structure and potential female fecundity in a Epinephelus guttatus spawning aggregation: Applying ultrasonic imaging

    USGS Publications Warehouse

    Whiteman, E.A.; Jennings, C.A.; Nemeth, R.S.

    2005-01-01

    Ultrasonic imaging was used to determine the spawning population structure and develop a fecundity estimation model for a red hind Epinephelus guttatus spawning aggregation within the Red Hind Bank Marine Conservation District, St Thomas, U.S.V.I. The spawning population showed considerable within-month and between-month variation in population size- and sex-structure. In the spawning season studied, males appeared to arrive at the aggregation site first in December although females represented a large proportion of the catch early in the aggregation periods in January and February. Spawning occurred in January and February, and size frequency distributions suggested that an influx of small females occurred during the second spawning month. An overall sex ratio of 2.9:1 (female:male) was recorded for the whole reproductive season. The sex ratio, however, differed between months and days within months. More females per male were recorded in January than in February when the sex ratio was male biased. Fecundity estimates for this species predicted very high potential fecundities (2.4 ?? 105-2.4 ?? 106 oocytes). The ultrasound model also illustrated a rapid increase in potential female fecundity with total length. Ultrasonic imaging may prove a valuable tool in population assessment for many species and locations in which invasive fishing methods are clearly undesirable. ?? 2005 The Fisheries Society of the British Isles.

  18. Outlier Loci Detect Intraspecific Biodiversity amongst Spring and Autumn Spawning Herring across Local Scales

    PubMed Central

    Bekkevold, Dorte; Gross, Riho; Arula, Timo; Helyar, Sarah J.; Ojaveer, Henn

    2016-01-01

    Herring, Clupea harengus, is one of the ecologically and commercially most important species in European northern seas, where two distinct ecotypes have been described based on spawning time; spring and autumn. To date, it is unknown if these spring and autumn spawning herring constitute genetically distinct units. We assessed levels of genetic divergence between spring and autumn spawning herring in the Baltic Sea using two types of DNA markers, microsatellites and Single Nucleotide Polymorphisms, and compared the results with data for autumn spawning North Sea herring. Temporally replicated analyses reveal clear genetic differences between ecotypes and hence support reproductive isolation. Loci showing non-neutral behaviour, so-called outlier loci, show convergence between autumn spawning herring from demographically disjoint populations, potentially reflecting selective processes associated with autumn spawning ecotypes. The abundance and exploitation of the two ecotypes have varied strongly over space and time in the Baltic Sea, where autumn spawners have faced strong depression for decades. The results therefore have practical implications by highlighting the need for specific management of these co-occurring ecotypes to meet requirements for sustainable exploitation and ensure optimal livelihood for coastal communities. PMID:27050440

  19. Outlier Loci Detect Intraspecific Biodiversity amongst Spring and Autumn Spawning Herring across Local Scales.

    PubMed

    Bekkevold, Dorte; Gross, Riho; Arula, Timo; Helyar, Sarah J; Ojaveer, Henn

    2016-01-01

    Herring, Clupea harengus, is one of the ecologically and commercially most important species in European northern seas, where two distinct ecotypes have been described based on spawning time; spring and autumn. To date, it is unknown if these spring and autumn spawning herring constitute genetically distinct units. We assessed levels of genetic divergence between spring and autumn spawning herring in the Baltic Sea using two types of DNA markers, microsatellites and Single Nucleotide Polymorphisms, and compared the results with data for autumn spawning North Sea herring. Temporally replicated analyses reveal clear genetic differences between ecotypes and hence support reproductive isolation. Loci showing non-neutral behaviour, so-called outlier loci, show convergence between autumn spawning herring from demographically disjoint populations, potentially reflecting selective processes associated with autumn spawning ecotypes. The abundance and exploitation of the two ecotypes have varied strongly over space and time in the Baltic Sea, where autumn spawners have faced strong depression for decades. The results therefore have practical implications by highlighting the need for specific management of these co-occurring ecotypes to meet requirements for sustainable exploitation and ensure optimal livelihood for coastal communities. PMID:27050440

  20. Thermal and hydrologic suitability of Lake Erie and its major tributaries for spawning of Asian carps

    USGS Publications Warehouse

    Kocovsky, Patrick M.; Chapman, Duane C.; McKenna, James E.

    2012-01-01

    Bighead carp Hypophthalmichthys nobilis, silver carp H. molitrix, and grass carp Ctenopharyngodon idella (hereafter Asian carps) have expanded throughout the Mississippi River basin and threaten to invade Lakes Michigan and Erie. Adult bighead carp and grass carp have been captured in Lake Erie, but self-sustaining populations probably do not exist. We examined thermal conditions within Lake Erie to determine if Asian carps would mature, and to estimate time of year when fish would reach spawning condition. We also examined whether thermal and hydrologic conditions in the largest tributaries to western and central Lake Erie were suitable for spawning of Asian carps. We used length of undammed river, predicted summer temperatures, and predicted water velocity during flood events to determine whether sufficient lengths of river are available for spawning of Asian carps. Most rivers we examined have at least 100 km of passable river and summer temperatures suitable (> 21 C) for rapid incubation of eggs of Asian carps. Predicted water velocity and temperature were sufficient to ensure that incubating eggs, which drift in the water column, would hatch before reaching Lake Erie for most flood events in most rivers if spawned far enough upstream. The Maumee, Sandusky, and Grand Rivers were predicted to be the most likely to support spawning of Asian carps. The Black, Huron, Portage, and Vermilion Rivers were predicted to be less suitable. The weight of the evidence suggests that the largest western and central Lake Erie tributaries are thermally and hydrologically suitable to support spawning of Asian carps.

  1. Phenotypic plasticity in the spawning traits of bigheaded carp (Hypophthalmichthys spp.) in novel ecosystems

    USGS Publications Warehouse

    Coulter, Alison A.; Keller, Doug; Amberg, Jon J.; Bailey, Elizabeth J.; Goforth, Reuben R.

    2013-01-01

    1. Bigheaded carp, including both silver (Hypophthalmichthys molitrix) and bighead (H. nobilis) carp, are successful invasive fishes that threaten global freshwater biodiversity. High phenotypic plasticity probably contributes to their success in novel ecosystems, although evidence of plasticity in several spawning traits has hitherto been largely anecdotal or speculative. 2. We collected drifting eggs from a Midwestern U.S.A. river from June to September 2011 and from April to June 2012 to investigate the spawning traits of bigheaded carp in novel ecosystems. 3. Unlike reports from the native range, the presence of drifting bigheaded carp eggs was not related to changes in hydrological regime or mean daily water temperature. Bigheaded carp also exhibited protracted spawning, since we found drifting eggs throughout the summer and as late as 1 September 2011. Finally, we detected bigheaded carp eggs in a river reach where the channel is c. 30 m wide with a catchment area of 4579 km2, the smallest stream in which spawning has yet been documented. 4. Taken with previous observations of spawning traits that depart from those observed within the native ranges of both bighead and silver carp, our findings provide direct evidence that bigheaded carp exhibit plastic spawning traits in novel ecosystems that may facilitate invasion and establishment in a wider range of river conditions than previously envisaged.

  2. Location Isn’t Everything: Timing of Spawning Aggregations Optimizes Larval Replenishment

    PubMed Central

    Donahue, Megan J.; Karnauskas, Mandy; Toews, Carl; Paris, Claire B.

    2015-01-01

    Many species of reef fishes form large spawning aggregations that are highly predictable in space and time. Prior research has suggested that aggregating fish derive fitness benefits not just from mating at high density but, also, from oceanographic features of the spatial locations where aggregations occur. Using a probabilistic biophysical model of larval dispersal coupled to a fine resolution hydrodynamic model of the Florida Straits, we develop a stochastic landscape of larval fitness. Tracking virtual larvae from release to settlement and incorporating changes in larval behavior through ontogeny, we found that larval success was sensitive to the timing of spawning. Indeed, propagules released during the observed spawning period had higher larval success rates than those released outside the observed spawning period. In contrast, larval success rates were relatively insensitive to the spatial position of the release site. In addition, minimum (rather than mean) larval survival was maximized during the observed spawning period, indicating a reproductive strategy that minimizes the probability of recruitment failure. Given this landscape of larval fitness, we take an inverse optimization approach to define a biological objective function that reflects a tradeoff between the mean and variance of larval success in a temporally variable environment. Using this objective function, we suggest that the length of the spawning period can provide insight into the tradeoff between reproductive risk and reward. PMID:26103162

  3. Seasonality of spawning by tropical anguillid eels around Sulawesi Island, Indonesia.

    PubMed

    Wouthuyzen, Sam; Aoyama, Jun; Sugeha, H Yulia; Miller, Michael J; Kuroki, Mari; Minegishi, Yuki; Suharti, Sasanti R; Tsukamoto, Katsumi

    2009-01-01

    Remarkably little is known about the life histories of the many tropical anguillid eels distributed across the Indo-Pacific region, and since the Danish expedition to study eels in the region in 1928 and 1929, research on these eels has only begun again in recent years. Sampling for anguillid leptocephali in the Indonesian Seas has been carried out recently to learn about the spawning ecology and larval distributions of tropical eels there. The leptocephali of Anguilla marmorata, Anguilla bicolor pacifica, Anguilla borneensis, Anguilla interioris, and Anguilla celebesensis were collected around Sulawesi Island both in May 2001 and October of 2002. The development of genetic identification techniques has enabled these leptocephali to be identified to species, and their distributions and sizes during different seasons indicated that there are differing life history patterns among sympatric species in the region. A. celebesensis was found to have been spawning in Tomini Bay of northeastern Sulawesi Island in March and April 2001, but apparently, no spawning had occurred in the late summer and fall of 2002. Studies on anguillid glass eels have suggested that tropical anguillids may spawn throughout much of year, but our research on leptocephali in Tomini Bay and data on the downstream migration of tropical anguillids in the major tributary to Tomini Bay indicate that A. celebesensis may have a distinct seasonal pattern of spawning possibly related to the regional monsoon cycles. This is the first evidence of seasonality of spawning in tropical anguillid eels whose life histories are only just beginning to be revealed. PMID:18850081

  4. Location Isn't Everything: Timing of Spawning Aggregations Optimizes Larval Replenishment.

    PubMed

    Donahue, Megan J; Karnauskas, Mandy; Toews, Carl; Paris, Claire B

    2015-01-01

    Many species of reef fishes form large spawning aggregations that are highly predictable in space and time. Prior research has suggested that aggregating fish derive fitness benefits not just from mating at high density but, also, from oceanographic features of the spatial locations where aggregations occur. Using a probabilistic biophysical model of larval dispersal coupled to a fine resolution hydrodynamic model of the Florida Straits, we develop a stochastic landscape of larval fitness. Tracking virtual larvae from release to settlement and incorporating changes in larval behavior through ontogeny, we found that larval success was sensitive to the timing of spawning. Indeed, propagules released during the observed spawning period had higher larval success rates than those released outside the observed spawning period. In contrast, larval success rates were relatively insensitive to the spatial position of the release site. In addition, minimum (rather than mean) larval survival was maximized during the observed spawning period, indicating a reproductive strategy that minimizes the probability of recruitment failure. Given this landscape of larval fitness, we take an inverse optimization approach to define a biological objective function that reflects a tradeoff between the mean and variance of larval success in a temporally variable environment. Using this objective function, we suggest that the length of the spawning period can provide insight into the tradeoff between reproductive risk and reward. PMID:26103162

  5. Oxygen depletion in coastal seas and the effective spawning stock biomass of an exploited fish species.

    PubMed

    Hinrichsen, H-H; von Dewitz, B; Dierking, J; Haslob, H; Makarchouk, A; Petereit, C; Voss, R

    2016-01-01

    Environmental conditions may have previously underappreciated effects on the reproductive processes of commercially exploited fish populations, for example eastern Baltic cod, that are living at the physiological limits of their distribution. In the Baltic Sea, salinity affects neutral egg buoyancy, which is positively correlated with egg survival, as only water layers away from the oxygen consumption-dominated sea bottom contain sufficient oxygen. Egg buoyancy is positively correlated to female spawner age/size. From observations in the Baltic Sea, a field-based relationship between egg diameter and buoyancy (floating depth) could be established. Hence, based on the age structure of the spawning stock, we quantify the number of effective spawners, which are able to reproduce under ambient hydrographic conditions. For the time period 1993-2010, our results revealed large variations in the horizontal extent of spawning habitat (1000-20 000 km(2)) and oxygen-dependent egg survival (10-80%). The novel concept of an effective spawning stock biomass takes into account offspring that survive depending on the spawning stock age/size structure, if reproductive success is related to egg buoyancy and the extent of hypoxic areas. Effective spawning stock biomass reflected the role of environmental conditions for Baltic cod recruitment better than the spawning stock biomass alone, highlighting the importance of including environmental information in ecosystem-based management approaches. PMID:26909164

  6. Spawning rings of exceptional points out of Dirac cones

    NASA Astrophysics Data System (ADS)

    Zhen, Bo; Hsu, Chia Wei; Igarashi, Yuichi; Lu, Ling; Kaminer, Ido; Pick, Adi; Chua, Song-Liang; Joannopoulos, John D.; Soljačić, Marin

    2015-09-01

    The Dirac cone underlies many unique electronic properties of graphene and topological insulators, and its band structure--two conical bands touching at a single point--has also been realized for photons in waveguide arrays, atoms in optical lattices, and through accidental degeneracy. Deformation of the Dirac cone often reveals intriguing properties; an example is the quantum Hall effect, where a constant magnetic field breaks the Dirac cone into isolated Landau levels. A seemingly unrelated phenomenon is the exceptional point, also known as the parity-time symmetry breaking point, where two resonances coincide in both their positions and widths. Exceptional points lead to counter-intuitive phenomena such as loss-induced transparency, unidirectional transmission or reflection, and lasers with reversed pump dependence or single-mode operation. Dirac cones and exceptional points are connected: it was theoretically suggested that certain non-Hermitian perturbations can deform a Dirac cone and spawn a ring of exceptional points. Here we experimentally demonstrate such an `exceptional ring' in a photonic crystal slab. Angle-resolved reflection measurements of the photonic crystal slab reveal that the peaks of reflectivity follow the conical band structure of a Dirac cone resulting from accidental degeneracy, whereas the complex eigenvalues of the system are deformed into a two-dimensional flat band enclosed by an exceptional ring. This deformation arises from the dissimilar radiation rates of dipole and quadrupole resonances, which play a role analogous to the loss and gain in parity-time symmetric systems. Our results indicate that the radiation existing in any open system can fundamentally alter its physical properties in ways previously expected only in the presence of material loss and gain.

  7. Redd site selection and spawning habitat use by fall chinook salmon: The importance of geomorphic features in large rivers

    SciTech Connect

    Geist, D.R. |; Dauble, D.D.

    1998-09-01

    Knowledge of the three-dimensional connectivity between rivers and groundwater within the hyporheic zone can be used to improve the definition of fall chinook salmon (Oncorhynchus tshawytscha) spawning habitat. Information exists on the microhabitat characteristics that define suitable salmon spawning habitat. However, traditional spawning habitat models that use these characteristics to predict available spawning habitat are restricted because they can not account for the heterogeneous nature of rivers. The authors present a conceptual spawning habitat model for fall chinook salmon that describes how geomorphic features of river channels create hydraulic processes, including hyporheic flows, that influence where salmon spawn in unconstrained reaches of large mainstem alluvial rivers. Two case studies based on empirical data from fall chinook salmon spawning areas in the Hanford Reach of the Columbia River are presented to illustrate important aspects of the conceptual model. The authors suggest that traditional habitat models and the conceptual model be combined to predict the limits of suitable fall chinook salmon spawning habitat. This approach can incorporate quantitative measures of river channel morphology, including general descriptors of geomorphic features at different spatial scales, in order to understand the processes influencing redd site selection and spawning habitat use. This information is needed in order to protect existing salmon spawning habitat in large rivers, as well as to recover habitat already lost.

  8. Spermatophore affects the egg-spawning and egg-carrying behavior in the female giant freshwater prawn, Macrobrachium rosenbergii.

    PubMed

    Kruangkum, Thanapong; Vanichviriyakit, Rapeepun; Chotwiwatthanakun, Charoonroj; Saetan, Jirawat; Tinikul, Yotsawan; Wanichanon, Chaitip; Cummins, Scott F; Hanna, Peter J; Sobhon, Prasert

    2015-10-01

    In crustaceans, mating occurs during the ecdysis after female molting. During this period, a male transfers its spermatophore into a female which, in some species, stores the spermatophore for a long period prior to spawning and fertilization. However, in some species including the giant freshwater prawn, Macrobrachium rosenbergii, the male deposits its spermataphore onto the external surface of the thoracic segment of the female which affects the spawning time and maternal behavior. This study investigated the spawning behavior of the M. rosenbergii females, which was divided into pre-spawning, spawning, and post-spawning phases. It was revealed that mated female prawns with attached spermatophore exhibited an earlier spawning than unmated individuals, leading to assessment of the factors that may elicit this phenomenon. Four groups of female prawns were allocated to groups including mating females with spermatophore still attached, mating females with the spermatophore removed, artificially inseminated females with spermatophores, and an unmated control. There was a significant reduction in the time of egg-spawning in the presence of spermatophores, and the mating activity was also a contributing factor. Furthermore, over 90% of the mated and artificially inseminated females in which spermatophores were deposited carried the eggs in the abdominal brood chamber until completion of embryonic development while others discarded the eggs within 2 days post-spawning. This study implies that the spermatophore may contain ovulation-inducing factors which stimulate an earlier spawning and fostering of brooding behavior. PMID:26388033

  9. Does fish reproduction and metabolic activity influence metal levels in fish intestinal parasites, acanthocephalans, during fish spawning and post-spawning period?

    PubMed

    Filipović Marijić, Vlatka; Vardić Smrzlić, Irena; Raspor, Biserka

    2014-10-01

    Application of fish intestinal parasites, acanthocephalans, as bioindicators in metal exposure assessment usually involves estimation of their metal levels and bioconcentration factors. Metal levels in parasite final host, fishes, are influenced by fish physiology but there is no data for acanthocephalan metal levels. Gastrointestinal Zn, Fe, Mn, Cd, Ag levels in European chub (Squalius cephalus L.) from the Sava River were significantly higher during chub spawning (April/May) compared to the post-spawning period (September). In acanthocephalans (Pomphorhynchus laevis and Acanthocephalus anguillae) significantly higher metal levels during chub spawning were observed only for Zn in P. laevis. Bioconcentration factors were twice as high for Fe, Mn, Ag, Pb in the post-spawning period, probably as a consequence of lower gastrointestinal metal levels in fish rather than metal exposure. Therefore, bioconcentration factors should be interpreted with caution, due to their possible variability in relation to fish physiology. In addition, gastrointestinal Cu, Cd and Pb levels were lower in infected than uninfected chub, indicating that metal variability in fishes might be affected by the presence of acanthocephalans. PMID:25048939

  10. Spawning areas of eastern Baltic cod revisited: Using hydrodynamic modelling to reveal spawning habitat suitability, egg survival probability, and connectivity patterns

    NASA Astrophysics Data System (ADS)

    Hinrichsen, H.-H.; Lehmann, A.; Petereit, C.; Nissling, A.; Ustups, D.; Bergström, U.; Hüssy, K.

    2016-04-01

    In the highly variable environment of the Baltic Sea two genetically distinct cod stocks exist, one west of the island of Bornholm, which is referred to as the western stock, and one to the east of Bornholm, the eastern stock. A hydrodynamic model combined with a Lagrangian particle tracking technique was utilised to provide spatially and temporally resolved long-term information on environmentally-related (i) spawning habitat size, (ii) egg/yolk-sac larval survival, (iii) separation of causes of mortality, and (iv) connectivity between spawning areas of eastern Baltic cod. Simulations were performed to quantify processes generating heterogeneity in spatial distribution of cod eggs and yolk sac larvae up to the first-feeding stage. The spatial extent of cod eggs represented as virtual drifters is primarily determined by oxygen and salinity conditions at spawning, which define the habitat requirement to which cod's physiology is suited for egg development. The highest habitat suitability occurred in the Bornholm Basin, followed by the Gdansk Deep, while relatively low habitat suitability was obtained for the Arkona and the Gotland Basin. During drift egg and yolk sac larval survival is to a large extent affected by sedimentation. Eggs initially released in the western spawning grounds (Arkona and Bornholm Basin) were more affected by sedimentation than those released in the eastern spawning grounds (Gdansk Deep and Gotland Basin). Highest relative survival of eastern Baltic cod eggs occurred in the Bornholm Basin, with a pronounced decrease towards the Gdansk Deep and the Gotland Basin. Relatively low survival rates in the Gdansk Deep and in the Gotland Basin were attributable to oxygen-dependent mortality. Low oxygen content had almost no impact on survival in the Arkona Basin. For all spawning areas temperature dependent mortality was only evident after severe winters. Egg buoyancy in relation to topographic features like bottom sills and strong bottom slopes

  11. Managing polyploidy in ex situ conservation genetics: the case of the critically endangered Adriatic sturgeon (Acipenser naccarii).

    PubMed

    Congiu, Leonardo; Pujolar, Jose Martin; Forlani, Anna; Cenadelli, Silvia; Dupanloup, Isabelle; Barbisan, Federica; Galli, Andrea; Fontana, Francesco

    2011-01-01

    While the current expansion of conservation genetics enables to address more efficiently the management of threatened species, alternative methods for genetic relatedness data analysis in polyploid species are necessary. Within this framework, we present a standardized and simple protocol specifically designed for polyploid species that can facilitate management of genetic diversity, as exemplified by the ex situ conservation program for the tetraploid Adriatic sturgeon Acipenser naccarii. A critically endangered endemic species of the Adriatic Sea tributaries, its persistence is strictly linked to the ex situ conservation of a single captive broodstock currently decimated to about 25 individuals, which represents the last remaining population of Adriatic sturgeon of certain wild origin. The genetic variability of three F1 broodstocks available as future breeders was estimated based on mitochondrial and microsatellite information and compared with the variability of the parental generation. Genetic data showed that the F1 stocks have only retained part of the genetic variation present in the original stock due to the few parent pairs used as founders. This prompts for the urgent improvement of the current F1 stocks by incorporating new founders that better represent the genetic diversity available. Following parental allocation based on band sharing values, we set up a user-friendly tool for selection of candidate breeders according to relatedness between all possible parent-pairs that secures the use of non-related individuals. The approach developed here could also be applied to other endangered tetraploid sturgeon species overexploited for caviar production, particularly in regions lacking proper infrastructure and/or expertise. PMID:21483472

  12. Isolation of Yersinia ruckeri strain H01 from farm-raised Amur Sturgeon Acipenser schrencki in China.

    PubMed

    Shaowu, Li; Di, Wang; Hongbai, Liu; Tongyan, Lu

    2013-03-01

    Yersinia ruckeri is the causative agent of enteric redmouth disease or yersiniosis, which affects salmonids and several other species of fish. However, there are no reports on the characteristics and pathogenicity of Y. ruckeri isolated from farm-raised Amur Sturgeon Acipenser schrencki. Here, we isolated and characterized Y. ruckeri strain H01 from the diseased Amur Sturgeon in China. The phenotypic and genotypic characteristics of Y. ruckeri were observed, and its virulence was tested by examining experimentally infected sturgeons. Examination of the flagellar morphology of Y. ruckeri by transmission electron microscopy showed five to eight peritrichous flagella located on the cell body. Actively dividing cells with an obvious cell membrane were approximately 0.64 μm in diameter and between 1.7 and 2.5 μm in length. The dose that was lethal to 50% of the test fish after intraperitoneal injection was determined to be 7.2×10(6) CFU, and Y. ruckeri could be reisolated from the liver and kidneys of infected sturgeon. Antimicrobial susceptibility tests showed that H01 was susceptible to 10 antimicrobial agents. Part of the 16S rRNA sequences (563 base pair) was amplified and sequenced to study the genotypic characterization in Y. ruckeri (GenBank accession number JQ657818). The phylogenetic tree revealed H01 was clustered together with Y. ruckeri strains. Together, this study describes the isolation, characterization, and phenotypic-genotypic analysis of a Y. ruckeri strain isolated from farm-raised Amur Sturgeon. The results discovered may provide some theoretical basis for the prevention and control of yersiniosis in Amur Sturgeon. PMID:23241058

  13. Effect of anaesthetics MS-222 and clove oil on blood biochemical parameters of juvenile Siberian sturgeon (Acipenser baerii)

    USGS Publications Warehouse

    Feng, G.; Zhuang, P.; Zhang, L.; Kynard, B.; Shi, X.; Duan, M.; Liu, J.; Huang, X.

    2011-01-01

    The effects of MS-222 and clove oil on blood biochemical parameters of juvenile Siberian sturgeon (Acipenser baerii) were studied. MS-222 caused higher glucose (GLU) concentrations in anaesthetic test groups than for the control group. Triglyceride (TGL) concentrations of fish in the 140 and 160mgL-1 groups were also significantly higher than those of other groups. Alanine aminotransferase (ALT) activity in the 140mgL-1 group was significantly higher than the level in 80, 100 and 120mgL-1 groups. Aspartate aminotransferase (AST) activity in the 140mgL-1 group was significantly higher than those in the 100 and 120mgL-1 groups. Levels of total protein (TP), cholesterol (CHOL) and alkaline phosphatase (ALP) in anaesthetic test groups were not significantly influenced by MS-222. Clove oil did not have significant effects on levels of GLU, TP, CHOL, ALT and ALP. TGL concentration of fish exposed to 180mgL-1 clove oil was significantly higher than those of the rest anaesthetic groups. AST activities of fish exposed to 120, 150 and 180mgL-1 were significantly higher than those of 60 and 90mgL-1. Overall, TGL and AST could be potentially used as indicators of anaesthetic stress for juvenile Siberian sturgeon. Based on blood biochemical parameters, the appropriate anaesthetic concentrations of MS-222 and clove oil were 80-120mgL-1 and 60-90mgL-1, respectively. Clove oil was a promising alternative to MS-222. ?? 2011 Blackwell Verlag, Berlin.

  14. Destruction of Listeria monocytogenes in sturgeon (Acipenser transmontanus) caviar by a combination of nisin with chemical antimicrobials or moderate heat.

    PubMed

    Al-Holy, M; Lin, M; Rasco, B

    2005-03-01

    The objective of this study was to investigate the effect of nisin in combination with heat or antimicrobial chemical treatments (such as lactic acid, chlorous acid, and sodium hypochlorite) on the inhibition of Listeria monocytogenes and total mesophiles in sturgeon (Acipenser transmontanus) caviar. The effects of nisin (250, 500, 750, and 1,000 IU/ml), lactic acid (1, 2, and 3%), chlorous acid (134 and 268 ppm), sodium hypochlorite (150 and 300 ppm), and heat at 60 degrees C for 3 min were evaluated for a five-strain mixture of L. monocytogenes and total mesophiles in sturgeon caviar containing 3.5% salt. Selected combinations of these antimicrobial treatments were also tested. Injured and viable L. monocytogenes cells were recovered using an overlay method. Treating caviar with > or =500 IU/ml nisin initially reduced L. monocytogenes by 2 to 2.5 log units. Chlorous acid (268 ppm) reduced L. monocytogenes from 7.7 log units to undetectable (<0.48 log units) after 4 days of storage at 4 degrees C. However, there were no synergistic effects observed for combinations of nisin (500 or 750 IU/ml) plus either lactic acid or chlorous acid. Lactic acid caused a slight reduction (approximately 1 log unit) in the microbial load during a 6-day period at 4 degrees C. Sodium hypochlorite was ineffective at the levels tested. Mild heating (60 degrees C for 3 min) with nisin synergistically reduced viable counts of L. monocytogenes and total mesophiles. No L. monocytogenes cells (<0.48 log units) were recovered from caviar treated with heat and nisin (750 IU/ml) after a storage period of 28 days at 4 degrees C. PMID:15771175

  15. Novel technique for visualizing primordial germ cells in sturgeons (Acipenser ruthenus, A. gueldenstaedtii, A. baerii, and Huso huso).

    PubMed

    Saito, Taiju; Psenicka, Martin

    2015-10-01

    Primordial germ cells (PGCs) are the origin of all germ cells in developing embryos. In the sturgeon embryo, PGCs develop from the vegetal hemisphere, which mainly acts as an extraembryonic source of nutrition. Current methods for studying sturgeon PGCs require either killing the fish or using costly and time-consuming histological procedures. Here, we demonstrate that visualization of sterlet (Acipenser ruthenus>) PGCs in vivo is feasible by simply labeling the vegetal hemisphere with fluorescein isothiocyanate (FITC)-dextran. We injected FITC-dextrans, with molecular weights varying between 10 000 and 2 000 000, into the vegetal pole of 1- to 4-cell stage embryos. At the neurula to tail-bud developmental stages, FITC-positive PGC-like cells appeared ventrally around the developing tail bud in the experimental group that received a high-molecular-weight FITC-dextran. The highest average number of FITC-positive PGC-like cells was observed in embryos injected with FITC-dextran having a molecular weight of 500 000 (FD-500). The pattern of migration of the labeled cells was identical to that of PGCs, clearly indicating that the FITC-positive PGC-like cells were PGCs. Labeled vegetal cells, except for the PGCs, were digested and excreted before the embryos starting feeding. FITC-labeled PGCs were observed in the developing gonads of fish for at least 3 mo after injection. We also found that FD-500 could be used to visualize PGCs in other sturgeon species. To the best of our knowledge, this report is the first to demonstrate in any animal species that PGCs can be visualized in vivo for a long period by the injection of a simple reagent. PMID:26134864

  16. Spawning Habitat Studies of Hanford Reach Fall Chinook Salmon (Oncorhynchus tshawytscha), Final Report.

    SciTech Connect

    Geist, David R.; Arntzen, Evan V.; Chien, Yi-Ju

    2009-03-02

    The Pacific Northwest National Laboratory conducted this study for the Bonneville Power Administration (BPA) with funding provided through the Northwest Power and Conservation Council(a) and the BPA Fish and Wildlife Program. The study was conducted in the Hanford Reach of the Columbia River. The goal of study was to determine the physical habitat factors necessary to define the redd capacity of fall Chinook salmon that spawn in large mainstem rivers like the Hanford Reach and Snake River. The study was originally commissioned in FY 1994 and then recommissioned in FY 2000 through the Fish and Wildlife Program rolling review of the Columbia River Basin projects. The work described in this report covers the period from 1994 through 2004; however, the majority of the information comes from the last four years of the study (2000 through 2004). Results from the work conducted from 1994 to 2000 were covered in an earlier report. More than any other stock of Pacific salmon, fall Chinook salmon (Oncorhynchus tshawytscha) have suffered severe impacts from the hydroelectric development in the Columbia River Basin. Fall Chinook salmon rely heavily on mainstem habitats for all phases of their life cycle, and mainstem hydroelectric dams have inundated or blocked areas that were historically used for spawning and rearing. The natural flow pattern that existed in the historic period has been altered by the dams, which in turn have affected the physical and biological template upon which fall Chinook salmon depend upon for successful reproduction. Operation of the dams to produce power to meet short-term needs in electricity (termed power peaking) produces unnatural fluctuations in flow over a 24-hour cycle. These flow fluctuations alter the physical habitat and disrupt the cues that salmon use to select spawning sites, as well as strand fish in near-shore habitat that becomes dewatered. The quality of spawning gravels has been affected by dam construction, flood protection, and

  17. Evaluation of Salmon Spawning Below Bonneville Dam, Annual Report October 2005 - September 2006.

    SciTech Connect

    Arntzen, Evan V.; Mueller, Robert P.; Murray, Christopher J.

    2007-09-21

    Since FY 2000, scientists at Pacific Northwest National Laboratory (PNNL) have conducted research to assess the extent of spawning by chum salmon (Oncorhynchus keta) and fall Chinook salmon (O. tshawytscha) in the lower mainstem Columbia River. Their work supports a larger project funded by the Bonneville Power Administration (BPA) aimed at characterizing the physical habitat used by mainstem fall Chinook and chum salmon populations. Multiple collaborators in addition to PNNL are involved in the BPA project--counterparts include the Washington Department of Fish and Wildlife (WDFW), U.S. Fish and Wildlife Service (USFWS), Pacific States Marine Fisheries Commission (PSMFC), U.S. Geological Survey (USGS), and Oregon Department of Fish and Wildlife (ODFW). Data resulting from the individual tasks each agency conducts are providing a sound scientific basis for developing strategies to operate the Federal Columbia River Power System (FCRPS) in ways that will effectively protect and enhance the chum and tule fall Chinook salmon populations--both listed as threatened under the Endangered Species Act (ESA). Fall Chinook salmon, thought to originate from Bonneville Hatchery, were first noted to be spawning downstream of Bonneville Dam by WDFW biologists in 1993. Known spawning areas include gravel beds on the Washington side of the river near Hamilton Creek and near Ives Island. Limited surveys of spawning ground were conducted in the area around Ives and Pierce islands from 1994 through 1997. Based on those surveys, it is believed that fall Chinook salmon are spawning successfully in this area. The size of this population from 1994 to 1996 was estimated at 1800 to 5200 fish. Chum salmon also have been documented spawning downstream of Bonneville Dam. Chum salmon were listed as threatened under the ESA in March 1999. At present there is a need to determine the number of fall Chinook and chum salmon spawning downstream of Bonneville Dam, the characteristics of their spawning

  18. Evaluation of Salmon Spawning Below Bonneville Dam, 2005-2006 Annual Report.

    SciTech Connect

    Arntzen, Evan; Mueller, Robert; Murray, Christopher

    2007-03-01

    Since FY 2000, scientists at Pacific Northwest National Laboratory (PNNL) have conducted research to assess the extent of spawning by chum salmon (Oncorhynchus keta) and fall Chinook salmon (O. tshawytscha) in the lower mainstem Columbia River. Their work supports a larger project funded by the Bonneville Power Administration (BPA) aimed at characterizing the physical habitat used by mainstem fall Chinook and chum salmon populations. Multiple collaborators in addition to PNNL are involved in the BPA project--counterparts include the Washington Department of Fish and Wildlife (WDFW), U.S. Fish and Wildlife Service (USFWS), Pacific States Marine Fisheries Commission (PSMFC), U.S. Geological Survey (USGS), and Oregon Department of Fish and Wildlife (ODFW). Data resulting from the individual tasks each agency conducts are providing a sound scientific basis for developing strategies to operate the Federal Columbia River Power System (FCRPS) in ways that will effectively protect and enhance the chum and tule fall Chinook salmon populations--both listed as threatened under the Endangered Species Act (ESA). Fall Chinook salmon, thought to originate from Bonneville Hatchery, were first noted to be spawning downstream of Bonneville Dam by WDFW biologists in 1993. Known spawning areas include gravel beds on the Washington side of the river near Hamilton Creek and near Ives Island. Limited surveys of spawning ground were conducted in the area around Ives and Pierce islands from 1994 through 1997. Based on those surveys, it is believed that fall Chinook salmon are spawning successfully in this area. The size of this population from 1994 to 1996 was estimated at 1800 to 5200 fish. Chum salmon also have been documented spawning downstream of Bonneville Dam. Chum salmon were listed as threatened under the ESA in March 1999. At present there is a need to determine the number of fall Chinook and chum salmon spawning downstream of Bonneville Dam, the characteristics of their spawning

  19. Bedform morphology of salmon spawning areas in a large gravel-bed river

    SciTech Connect

    Hanrahan, Timothy P.

    2007-05-01

    While the importance of river channel morphology to salmon spawning habitat is increasingly recognized, quantitative measures of the relationships between channel morphology and habitat use are lacking. Such quantitative measures are necessary as management and regulatory agencies within the Pacific Northwestern region of the USA, and elsewhere, seek to quantify potential spawning habitat and develop recovery goals for declining salmon populations. The objective of this study was to determine if fall Chinook salmon (Oncorhynchus tshawytscha) spawning areas in the Snake River, Idaho, USA, were correlated with specific bed form types at the pool-riffle scale. A bed form differencing technique was used to objectively quantify the longitudinal riverbed profile into four distinct pool-riffle units that were independent of discharge. The vertical location of thalweg points within these units was quantified with a riffle proximity index. Chinook salmon spawning areas were mapped and correlated with the pool-riffle units through the use of cross-tabulation tables. The results indicate that 84% of fall Chinook salmon spawning areas were correlated with riffles (Chi-square=152.1, df=3, p<0.001), with 53% of those areas located on the upstream side of riffle crests. The majority of Snake River fall Chinook salmon spawning occurred at a vertical location within 80% of the nearest riffle crest elevation. The analyses of bed form morphology will assist regional fish mangers in quantifying existing and potential fall Chinook salmon spawning habitat, and will provide a quantitative framework for evaluating general ecological implications of channel morphology in large gravel-bed rivers.

  20. Evaluation of Salmon Spawning Below Bonneville Dam Annual Report October 2006 - September 2007.

    SciTech Connect

    Arntzen, Evan V.; Mueller, Robert P.; Murray, Katherine J.; Bott, Yi-Ju

    2008-08-08

    From 1999 through 2007, the Fish and Wildlife Program of the Bonneville Power Administration funded a project to determine the number of fall Chinook and chum salmon spawning downstream of Bonneville Dam, the characteristics of their spawning areas, and the flows necessary to ensure their long-term survival. Data were collected to ensure that established flow guidelines are appropriate and provide adequate protection for the species of concern. The projects objectives are consistent with the high priority placed by the Northwest Power and Conservation Council Independent Scientific Advisory Board and the salmon managers on determining the importance of mainstem habitats to the production of salmon in the Columbia River Basin. Because of the influence of mainstem habitat on salmon production, there is a continued need to better understand the physical habitat variables used by mainstem fall Chinook and chum salmon populations and the effects of hydropower project operations on spawning and incubation. During FY 2007, Pacific Northwest National Laboratory focused on (1) locating and mapping deep-water fall Chinook salmon and chum salmon spawning areas, (2) investigating the interaction between groundwater and surface water near fall Chinook and chum salmon spawning areas, and (3) providing in-season hyporheic temperature and water surface elevation data to assist state agencies with emergence timing and redd dewatering estimates. This report documents the studies and tasks performed by PNNL during FY 2007. Chapter 1 provides a description of the searches conducted for deepwater redds-adjacent to Pierce and Ives islands for fall Chinook salmon and near the Interstate 205 bridge for chum salmon. The chapter also provides data on redd location, information about habitat associations, and estimates of total spawning populations. Chapter 2 documents the collection of data on riverbed and river temperatures and water surface elevations, from the onset of spawning to the

  1. Reproductive longevity and fecundity associated with nonannual spawning in cui-ui

    USGS Publications Warehouse

    Scoppettone, G.G.; Rissler, P.H.; Buettner, M.E.

    2000-01-01

    The cui-ui Chasmistes cujus, a long-lived (40 years or more) and highly fecund catostomid, is often prevented from spawning in drought years. We studied the effect of cui-ui age on egg viability and the effect of nonannual spawning on fecundity in relation to length, age, and growth rate. Egg hatching and survival of swim-up larvae were examined for the offspring of first-time spawners, intermediate-aged females, and old females. Fecundity was tested for three growth categories (fast, intermediate, and slow) in years that were sufficiently wet to allow fish to spawn in the Truckee River and after dry years when fish did not spawn because of river inaccessibility. Females in the fast-growth category were first-time spawners, those in the middle-growth category were young to middle aged, and those in the slow-growth category were middle aged to old. Females up to 44 years of age still had viable eggs and a reproductive life of at least 29 years. Fecundity was greater after no-spawn years (dry year) compared with a spawn year (wet year), especially for fish in the slow-growth category. This study provides insight into the reproductive adaptation of a long-lived western North American catostomid and suggests possible reasons for the wide variation in fecundity in other long-lived catostomids. Our data will be used to improve the accuracy of an existing cui-ui population viability model. The revised model will have greater sensitivity to cui-ui survival relative to their spawning frequency and, thus, contribute to better management of conditions needed for the long-term survival of endangered cui-ui.

  2. High Variance within Salmonid Spawning Gravels at Restoration Sites Creates More Suitable Habitat within the Hyporheic Zone

    NASA Astrophysics Data System (ADS)

    Janes, M. K.; Heffernan, J. E.; Rosenberry, J. W.; Horner, T.

    2012-12-01

    The Lower American River has historically provided natural spawning habitat for approximately one third of Northern California's salmon population. However, since the construction of Folsom and Nimbus Dams, downstream reaches have become sediment starved and periodic high outflow from the dam has caused channel armoring and incision, thereby degrading the natural spawning habitat. Restoration work on spawning sites in the Lower American River has consisted primarily of importing gravel to create riffles during periods of moderate flow. This is an effort to mitigate armoring of the riverbed and to rehabilitate salmonid spawning habitat by providing suitable grain size for all stages of spawning (redd construction, incubation, and emergence). Since restoration activities began, all rehabilitated sites have not been equally used for spawning. This study attempts to examine and compare the physical properties of each site in order to ascertain which characteristics create more suitable rehabilitated habitat. To do this, we compared restored areas to pre-restoration conditions through the assessment of three main aspects of the restored spawning habitat; grain size and its natural mobility, water flow in the surface and subsurface, and intragravel water quality. We found that some augmentation sites are more heterogeneous than others, and this correlates with higher spawning use. Most spawning was at fin height, and salmonids tend to use sites with higher depth variance (surface features) and higher variance in flow directions and velocities. With time, salmonids alter the spawning sites, creating small ridges and valleys perpendicular to flow. This creates more variable subsurface flow and generates hyporheic flow through the new gravel. This may have an effect on spawning as the more seasoned additions have a higher frequency of spawning than the newer augmentations. In order to efficiently rehabilitate a site and expedite the "seasoning process", creating variance

  3. Evaluation of Fall Chinook and Chum Salmon Spawning below Bonneville Dam; 2002-2003 Annual Report.

    SciTech Connect

    van der Naald, Wayne; Clark, Roy; Brooks, Robert

    2004-01-01

    In 2002 a total of 364 adult fall chinook and 472 chum were sampled for biological data in the Ives and Pierce islands area below Bonneville Dam. Vital statistics were developed from 290 fall chinook and 403 chum samples. The peak redd count for fall chinook was 214. The peak redd count for chum was 776. Peak spawning time for fall chinook was set at approximately 15 November. Peak spawning time for chum occurred approximately 6 December. There were estimated to be a total of 1,881 fall chinook spawning below Bonneville Dam in 2002. The study area's 2002 chum population was estimated to be 4,232 spawning fish. Temperature unit data suggests that below Bonneville Dam 2002 brood bright stock, fall chinook emergence began on February 3 2003 and ended 7 May 2003, with peak emergence occurring 20 April. 2002 brood juvenile chum emergence below Bonneville Dam began 27 January and continued through 6 April 2003. Peak chum emergence took place 1 March. A total of 10,925 juvenile chinook and 1,577 juvenile chum were sampled between the dates of 24 January and 21 July 2003 below Bonneville Dam. Juvenile chum migrated from the study area in the 40-55 mm fork length range. Migration of chum occurred during the months of March, April and May. Sampling results suggest fall chinook migration from rearing areas took place during the month of June 2003 when juvenile fall chinook were in the 65 to 80 mm fork length size range. Adult and juvenile sampling below Bonneville Dam provided information to assist in determining the stock of fall chinook and chum spawning and rearing below Bonneville Dam. Based on observed spawning times, adult age and sex composition, juvenile emergence timing, juvenile migration timing and juvenile size at the time of migration, it appears that in 2002 and 2003 the majority of fall chinook using the area below Bonneville Dam were of a late-spawning, bright stock of fall chinook. Observed spawning times, adult age and sex composition, GSI and DNA analysis

  4. Evaluation of Fall Chinook and Chum Salmon Spawning below Bonneville Dam; 2003-2004 Annual Report.

    SciTech Connect

    van der Naald, Wayne; Duff, Cameron; Brooks, Robert

    2005-01-01

    In 2003 a total of 253 adult fall chinook and 113 chum were sampled for biological data in the Ives and Pierce islands area below Bonneville Dam. Vital statistics were developed from 221 fall chinook and 109 chum samples. The peak redd count for fall chinook was 190. The peak redd count for chum was 262. Peak spawning time for fall chinook was set at approximately 24 November. Peak spawning time for chum occurred approximately 24 November. There were estimated to be a total of 1,533 fall chinook spawning below Bonneville Dam in 2003. The study area's 2003 chum population was estimated to be 688 spawning fish. Temperature unit data suggests that below Bonneville Dam 2003 brood bright stock, fall chinook emergence began on January 6, 2004 and ended 28 April 2004, with peak emergence occurring 13 April. 2003 brood juvenile chum emergence below Bonneville Dam began 22 February and continued through 15 April 2004. Peak chum emergence took place 25 March. A total of 25,433 juvenile chinook and 4,864 juvenile chum were sampled between the dates of 20 January and 28 June 2004 below Bonneville Dam. Juvenile chum migrated from the study area in the 40-55 mm fork length range. Migration of chum occurred during the months of March, April and May. Sampling results suggest fall chinook migration from rearing areas took place during the month of June 2004 when juvenile fall chinook were in the 65 to 80 mm fork length size range. Adult and juvenile sampling below Bonneville Dam provided information to assist in determining the stock of fall chinook and chum spawning and rearing below Bonneville Dam. Based on observed spawning times, adult age and sex composition, juvenile emergence timing, juvenile migration timing and juvenile size at the time of migration, it appears that in 2003 all of the fall chinook using the area below Bonneville Dam were of a late-spawning, bright stock. Observed spawning times, adult age and sex composition, GSI and DNA analysis, juvenile emergence timing

  5. Importance of reservoir tributaries to spawning of migratory fish in the upper Paraná River

    USGS Publications Warehouse

    da Silva, P.S.; Makrakis, Maristela Cavicchioli; Miranda, Leandro E.; Makrakis, Sergio; Assumpcao, L.; Paula, S.; Dias, João Henrique Pinheiro; Marques, H.

    2015-01-01

    Regulation of rivers by dams transforms previously lotic reaches above the dam into lentic ones and limits or prevents longitudinal connectivity, which impairs access to suitable habitats for the reproduction of many migratory fish species. Frequently, unregulated tributaries can provide important habitat heterogeneity to a regulated river and may mitigate the influence of impoundments on the mainstem river. We evaluated the importance of tributaries to spawning of migratory fish species over three spawning seasons, by comparing several abiotic conditions and larval fish distributions in four rivers that are tributaries to an impounded reach of the Upper Parana River, Brazil. Our study confirmed reproduction of at least 8 long-distance migrators, likely nine, out of a total of 19 occurring in the Upper Parana River. Total larval densities and percentage species composition differed among tributaries, but the differences were not consistent among spawning seasons and unexpectedly were not strongly related to annual differences in temperature and hydrology. We hypothesize that under present conditions, densities of larvae of migratory species may be better related to efficiency of fish passage facilities than to temperature and hydrology. Our study indicates that adult fish are finding suitable habitat for spawning in tributaries, fish eggs are developing into larvae, and larvae are finding suitable rearing space in lagoons adjacent to the tributaries. Our findings also suggest the need for establishment of protected areas in unregulated and lightly regulated tributaries to preserve essential spawning and nursery habitats.

  6. Potential spawning habitat for lake trout on Julian's Reef, Lake Michigan

    USGS Publications Warehouse

    Edsall, Thomas A.; Kennedy, Gregory W.

    1996-01-01

    Julian's Reef is an historical spawning ground for lake trout (Salvelinus namaycush) in southwestern Lake Michigan. It is a designated lake trout refuge and is the focus of lake trout restoration efforts in Illinois waters of the lake. We studied the reef to determine its potential as spawning habitat for stocked lake trout. We used side-scan sonar and a remotely operated vehicle equipped with a video camera to survey and map 156 ha of lake bed on the southeast portion of the reef, where an earlier study revealed the presence of loose-rock substrate potentially suitable for use by spawning lake trout. Our survey showed that the substrate on the reef that most closely resembled that described in the literature as suitable for spawning by stocked lake trout in the Great Lakes was rubble patches with interstitial depths greater than 20 cm. These rubble patches occupied about 2 ha of the 13-ha expanse of bedrock and rubble substrate near the reef crest in the surveyed area. We estimated that these rubble patches, if fully used by spawning lake trout, could accommodate egg deposition by at least 1,300–3,300 2.7-kg females.

  7. Coral-Bacterial Communities before and after a Coral Mass Spawning Event on Ningaloo Reef

    PubMed Central

    Ceh, Janja; Raina, Jean-Baptiste; Soo, Rochelle M.; van Keulen, Mike; Bourne, David G.

    2012-01-01

    Bacteria associated with three coral species, Acropora tenuis, Pocillopora damicornis and Tubastrea faulkneri, were assessed before and after coral mass spawning on Ningaloo Reef in Western Australia. Two colonies of each species were sampled before and after the mass spawning event and two additional samples were collected for P. damicornis after planulation. A variable 470 bp region of the 16 S rRNA gene was selected for pyrosequencing to provide an understanding of potential variations in coral-associated bacterial diversity and community structure. Bacterial diversity increased for all coral species after spawning as assessed by Chao1 diversity indicators. Minimal changes in community structure were observed at the class level and data at the taxonomical level of genus incorporated into a PCA analysis indicated that despite bacterial diversity increasing after spawning, coral-associated community structure did not shift greatly with samples grouped according to species. However, interesting changes could be detected from the dataset; for example, α-Proteobacteria increased in relative abundance after coral spawning and particularly the Roseobacter clade was found to be prominent in all coral species, indicating that this group may be important in coral reproduction. PMID:22629343

  8. Spawning habitat and behavior of Gila trout, a rare salmonid of the southwestern United States

    SciTech Connect

    Rinne, J.N.

    1980-01-01

    The spawning season of Gila trout, Salmo gilae Miller, in three streams in the Gila National Forest, New Mexico, began in early April at the lowest elevation and continued through June at the highest elevation. Water temperature and stream flow interacted to induce spawning; however, the former was more important. Spawning commenced at water temperatures near 8 C. Redds were normally in 6 to 15 cm deep water, about a quarter of the stream width from one bank and within 5 m of cover. The substrate was predominantly gravel and small pebble (0.2 to 3.8 cm). Spawning fish selected redd sites based on depth of water and substrate rather than on water velocity. Redds ranged in area from less than 0.1 m/sup 2/ to nearly 2.0 m/sup 2/ and averaged 3 to 4 cm in structural depth. Normally a single fish or a pair of fish occupied a redd, but occupancy by three to four fish was common. Most spawning activity occurred between 1300 and 1600 hours. Fry (15 to 20 mm long) emerged in 8 to 10 weeks and inhibited riffle areas. Absence of fry from pools occupied by adults indicated that cannibalism may occur.

  9. Spawning activity of the Australian lungfish Neoceratodus forsteri in an impoundment.

    PubMed

    Roberts, D T; Mallett, S; Krück, N C; Loh, W; Tibbetts, I

    2014-01-01

    This study assessed the spawning activity of the threatened Australian lungfish Neoceratodus forsteri by measuring egg densities within the artificial habitat of a large impoundment (Lake Wivenhoe, Australia). Eggs were sampled (August to November 2009) from multiple locations across the impoundment, but occurred at highest densities in water shallower than 40 cm along shorelines with a dense cover of submerged terrestrial vegetation. The numbers of eggs declined over the study period and all samples were dominated by early developmental stages and high proportions of unviable eggs. The quality of the littoral spawning habitats declined over the study as flooded terrestrial grasses decomposed and filamentous algae coverage increased. Water temperatures at the spawning site exhibited extreme variations, ranging over 20·4° C in water shallower than 5 cm. Dissolved oxygen concentrations regularly declined to <1 mg l⁻¹ at 40 and 80 cm water depth. Spawning habitats utilised by N. forsteri within impoundments expose embryos to increased risk of desiccation or excessive submergence through water-level variations, and extremes in temperature and dissolved oxygen concentration that present numerous challenges for successful spawning and recruitment of N. forsteri in large impoundment environments. PMID:24383803

  10. Data Mining on Large Data Set for Predicting Salmon Spawning Habitat

    SciTech Connect

    Xie, YuLong; Murray, Christopher J.; Hanrahan, Timothy P.; Geist, David R.

    2008-07-01

    Hydraulic properties related to river flow affect salmon spawning habitat. Accurate prediction of salmon spawning habitat and understanding the influential properties on the spawning behavior are of great interest for hydroelectric dam management. Previous research predicted salmon spawning habitat through deriving river specific spawning suitability indices and employing a function estimate method like logistic regression on several static river flow related properties and had some success. The objective of this study was two-fold. First dynamic river flow properties associated with upstream dam operation were successfully derived from a huge set of time series of both water velocity and water depth for about one fifth of a million habitat cells through principal component analysis (PCA) using nonlinear iterative partial least squares (NIPLAS). The inclusion of dynamic variables in the models greatly improved the model prediction. Secondly, nine machine learning methods were applied to the data and it was found that decision tree and rule induction methods were generally outperformed usually used logistic regression. Specifically random forest, an advanced decision tree algorithm, provided unanimous better results. Over-prediction problem in previous studies were greatly alleviated.

  11. Transcriptional Profiling Reveals Differential Gene Expression of Amur Ide (Leuciscus waleckii) during Spawning Migration

    PubMed Central

    Cui, Jun; Xu, Jian; Zhang, Songhao; Wang, Kai; Jiang, Yanliang; Mahboob, Shahid; Al-Ghanim, Khalid A.; Xu, Peng

    2015-01-01

    Amur ide (Leuciscus waleckii), an important aquaculture species, inhabits neutral freshwater but can tolerate high salinity or alkalinity. As an extreme example, the population in Dali Nor lake inhabits alkalized soda water permanently, and migrates from alkaline water to neutral freshwater to spawn. In this study, we performed comparative transcriptome profiling study on the livers of Amur ide to interrogate the expression differences between the population that permanently inhabit freshwater in Ganggeng Nor lake (FW) and the spawning population that recently migrated from alkaline water into freshwater (SM). A total of 637,234,880 reads were generated, resulting in 53,440 assembled contigs that were used as reference sequences. Comparisons of these transcriptome files revealed 444 unigenes with significant differential expression (p-value ≤ 0.01, fold-change ≥ 2), including 246 genes that were up-regulated in SM and 198 genes that were up-regulated in FW. The gene ontology (GO) enrichment analysis and KEGG pathway analysis indicated that the mTOR signaling pathway, Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway, and oxidative phosphorylation were highly likely to affect physiological changes during spawning migration. Overall, this study demonstrates that transcriptome changes played a role in Amur ide spawning migration. These results provide a foundation for further analyses on the physiological and molecular mechanisms underlying Amur ide spawning migration. PMID:26096003

  12. Does dopamine block the spawning of the acroporid coral Acropora tenuis?

    PubMed Central

    Isomura, N.; Yamauchi, C.; Takeuchi, Y.; Takemura, A.

    2013-01-01

    Most corals undergo spawning after a particular moon phase, but how moon-related spawning is endogenously regulated in corals remains unknown. The objective of the present study was to evaluate whether dopamine (DA) affects spawning in Acropora tenuis. When pieces of four A. tenuis colonies were reared under a natural photoperiod and water temperature, spawning was observed after the predicted moon phase. After exposure to water containing DA at 0.1 μM, pieces of the same colonies only released 5 to 10 bundles. Co-treatment with DA and pimozide (D1 and D2 receptors antagonist), but not domperidone (D2 receptor antagonist), induced mass release of bundles from the colonies. A cross-experiment revealed high fertilization rates between the control colonies (95%) and between the control and DA-treated colonies (90%), suggesting that gametes developed normally in coral tissue. Therefore, DA appears to have an inhibitory effect on the spawning of A. tenuis. PMID:24026104

  13. Prey resources before spawning influence gonadal investment of female, but not male, white crappie

    USGS Publications Warehouse

    Bunnell, D.B.; Thomas, S.E.; Stein, R.A.

    2007-01-01

    In this study, an outdoor pool experiment was used to evaluate the effect of prey resources during 4 months before spawning on the gonadal investments of male and female white crappie Pomoxis annularis, a popular freshwater sportfish that exhibits erratic recruitment. Fish were assigned one of three feeding treatments: starved, fed once every 5 days (intermediate) or fed daily (high). All measurements of male testes (i.e. wet mass, energy density and spermatocrit) were similar across treatments. Conversely, high-fed females produced larger ovaries than those of intermediate-fed and starved fish, and invested more energy in their ovaries than starved fish. Compared to pre-experiment fish, starved and intermediate-fed females appeared to increase their ovary size by relying on liver energy stores (‘capital’ spawning). Conversely, high-fed females increased liver and gonad mass, implying an ‘income’-spawning strategy (where gonads are built from recently acquired energy). Fecundity did not differ among treatments, but high-fed fish built larger eggs than those starved. Females rarely ‘skipped’ spawning opportunities when prey resources were low, as only 8% of starved females and 8% of intermediate-fed females lacked vitellogenic eggs. These results suggest that limited prey resources during the months before spawning can limit ovary production, which, in turn, can limit reproductive success of white crappies.

  14. Differences in spawning date between populations of common frog reveal local adaptation

    PubMed Central

    Phillimore, Albert B.; Hadfield, Jarrod D.; Jones, Owen R.; Smithers, Richard J.

    2010-01-01

    Phenotypic differences between populations often correlate with climate variables, resulting from a combination of environment-induced plasticity and local adaptation. Species comprising populations that are genetically adapted to local climatic conditions should be more vulnerable to climate change than those comprising phenotypically plastic populations. Assessment of local adaptation generally requires logistically challenging experiments. Here, using a unique approach and a large dataset (>50,000 observations from across Britain), we compare the covariation in temperature and first spawning dates of the common frog (Rana temporaria) across space with that across time. We show that although all populations exhibit a plastic response to temperature, spawning earlier in warmer years, between-population differences in first spawning dates are dominated by local adaptation. Given climate change projections for Britain in 2050–2070, we project that for populations to remain as locally adapted as contemporary populations will require first spawning date to advance by ∼21–39 days but that plasticity alone will only enable an advance of ∼5–9 days. Populations may thus face a microevolutionary and gene flow challenge to advance first spawning date by a further ∼16–30 days over the next 50 years. PMID:20404185

  15. Effects of hydropeaking on the spawning behaviour of Atlantic salmon Salmo salar and brown trout Salmo trutta.

    PubMed

    Vollset, K W; Skoglund, H; Wiers, T; Barlaup, B T

    2016-06-01

    An in situ camera set-up was used to study the spawning activity of Atlantic salmon Salmo salar and brown trout Salmo trutta throughout two consecutive seasons in a spawning area affected by hydropower-related pulse flows due to hydropeaking. The purpose was to test whether the flow variation discouraged spawning in shallow areas or motivated spawning into areas with elevated risk of incubation mortality. There were more S. salar observed on the spawning ground during days with high discharge. The presence of S. salar in the spawning grounds was not affected by the hydropeaking cycles of the preceding night. Female S. salar were observed preparing nests within the first hour after water discharge had increased to levels suitable for spawning. In contrast, the number of S. trutta was not correlated with flow and nest preparation was also observed at a discharge corresponding to the lowest discharge levels during a hydropeaking cycle. Survival was generally high in nests excavated the following winter, with only 5·4% suffering mortality due to dewatering. The results suggest that S. salar may respond rapidly to variable-flow conditions and utilize short windows with suitable flows for spawning. Smaller S. trutta may utilize low-flow conditions to spawn in areas that are not habitable by larger S. salar during low flow. PMID:27125209

  16. Analysis of spawning behavior, habitat, and season of the federally threatened Etheostoma scotti, Cherokee darter (Osteichthyes: Percidae)

    USGS Publications Warehouse

    Storey, C.M.; Porter, B.A.; Freeman, Mary C.; Freeman, B.J.

    2006-01-01

    Etheostoma scotti (Cherokee darter) is a member of the subgenus Ulocentra and a federally threatened endemic to the Etowah River system, GA. Field observations of spawning behavior of the Cherokee darter were made at five stream sites to identify spawning season and habitat over two field seasons. Cherokee darters primarily spawn in pool habitats between mid-March and early June, at temperatures between 11 and 18 ?C. Egg deposition was typically on large gravel substrate, but ranged from gravel to bedrock in size and included woody debris. Spawning occurred in a variety of depths (0.09-0.59 m) and velocities (0-0.68 m/s).

  17. The utility of a long-term acoustic recording system for detecting white seabass Atractoscion nobilis spawning sounds.

    PubMed

    Aalbers, S A; Sepulveda, C A

    2012-11-01

    This study reports the use of a long-term acoustic recording system (LARS) to remotely monitor white seabass Atractoscion nobilis spawning sounds at three sites along the southern California coastline, adjacent to Camp Pendleton. On the basis of previous studies of A. nobilis sound production relative to periods of known spawning activity, LARS were set to continuously record ambient sounds for a 2 h period around sunset from April to June 2009. Acoustic analyses identified A. nobilis courtship sounds on 89, 28 and 45% of the days at the three locations, respectively. From 474 h of acoustic data, spawning-related sounds (chants) were detected on 19 occasions in 2009 with an additional 11 spawning chants recorded during a 2007 validation period. Most spawning chants occurred within 30 min of sunset during the months of May and June at a mean ±S.D. surface temperature of 18.2 ± 1.2° C. Consecutive daily spawning activity was not apparent at any sites in 2009. Atractoscion nobilis spawning chants were recorded at all three sites, suggesting that shallow rocky reefs which support kelp forests provide suitable A. nobilis spawning habitat. Results confirm the utility of passive acoustic recorders for identifying A. nobilis spawning periods and locations. PMID:23130687

  18. Hyporheic discharge of river water into fall chinook salmon (Oncorhynchus tshawytscha) spawning areas in the Hanford Reach, Columbia River

    SciTech Connect

    Geist, David R. )

    1999-12-01

    Fall chinook salmon (Oncorhynchus tshawytscha) spawned predominantly in areas of the Hanford Reach of the Columbia River where hyporheic water discharged into the river channel. This upwelling water had a dissolved solids content (i.e., specific conductance) indicative of river water and was presumed to have entered highly permeable riverbed substrate at locations upstream of the spawning areas. Hyporheic discharge zones composed of undiluted ground water or areas with little or no upwelling were not used by spawning salmon. Rates of upwelling into spawning areas averaged 1,200 L?m-2?day-1 (95% C.I.= 784 to 1,665 L?m-2?day-1) as compared to approximately 500 L?m-2?day-1 (95% C.I.= 303 to 1,159 L?m-2?day-1) in non-spawning areas. Dissolved oxygen content of the hyporheic discharge near salmon spawning areas was about 9 mg?L-1 (+ 0.4 mg?L-1) whereas in non-spawning areas dissolved oxygen values were 7 mg?L-1 (+ 0.9 mg?L-1) or lower. In both cases dissolved oxygen of the river water was higher (11.3+ 0.3 mg?L-1). Physical and chemical gradients between the hyporheic zone and the river may provide cues for adult salmon to locate suitable spawning areas. This information will help fisheries managers to describe the suitability of salmon spawning habitat in large rivers.

  19. Signaling cascades and the importance of moonlight in coral broadcast mass spawning.

    PubMed

    Kaniewska, Paulina; Alon, Shahar; Karako-Lampert, Sarit; Hoegh-Guldberg, Ove; Levy, Oren

    2015-01-01

    Many reef-building corals participate in a mass-spawning event that occurs yearly on the Great Barrier Reef. This coral reproductive event is one of earth's most prominent examples of synchronised behavior, and coral reproductive success is vital to the persistence of coral reef ecosystems. Although several environmental cues have been implicated in the timing of mass spawning, the specific sensory cues that function together with endogenous clock mechanisms to ensure accurate timing of gamete release are largely unknown. Here, we show that moonlight is an important external stimulus for mass spawning synchrony and describe the potential mechanisms underlying the ability of corals to detect environmental triggers for the signaling cascades that ultimately result in gamete release. Our study increases the understanding of reproductive chronobiology in corals and strongly supports the hypothesis that coral gamete release is achieved by a complex array of potential neurohormones and light-sensing molecules. PMID:26668113

  20. Apparent genetic homogeneity of spawning striped bass in the upper Chesapeak Bay

    SciTech Connect

    Sidell, B.D.; Otto, R.G.; Powers, D.A. Karweit, M.; Smith, J.

    1980-01-01

    The possible existence of genetically distinct populations of spawning striped bass (Morone saxatilis) in the river systems of the upper Chesapeake Bay was investigated by a biochemical genetic approach. Samples of blood and liver from adult fish were obtained during the 1976 spawning runs from the Rappanhannock (Virginia), Potomac, Choptank, Sassafras, Bohemia, and Elk rivers (Maryland), and Maryland waters of the Chesapeake and Delaware Canal. Samples were analyzed for frequency of occurrence of a polymorphic liver enzyme, glycerol-3-phosphate dehydrogenase, and variable serum proteins which were not correlated with age or sex. Multivariate and Bayesian analyses of these data indicate apparent genetic homogeneity of spawning bass within the upper Chesapeake Bay. If natal stream homing occurs, a sufficient number of wanderers may provide significant gene flow among river systems. The results suggest that long-term management of the fishery need not be totally on the basis of separate river units.

  1. Spawning of zebra mussels (Dreissena polymorpha) and rearing of veligers under laboratory conditions

    USGS Publications Warehouse

    Nichols, S. Jerrine

    1992-01-01

    The spawning cycle of the zebra mussel, Dreissena polymorpha, is amenable to laboratory manipulations. Techniques are presented that can be used to initiate spawning and rear veligers from fertilized egg to settlement stage. Spawning can be induced in sexually mature mussels by temperature flucuations or by the addition of ripe gametes. Embryonic survival is excellent until the straight-hinge stage when the first wave of mortality occurs, usually due to improper food. The second critical stage of development occurs just prior to settlement when mortality increases again. Veliger mortality averaged over 90% from egg to settlement. The results indicate that obtaining large numbers of veligers for laboratory experiments to be conducted year-round is difficult.

  2. Effect of 'Azotobacter' Bioinoculant on the Growth and Substrate Utilization Potential of Pleurotus eous Seed Spawn

    PubMed Central

    Parani, K.; Pothiraj, C.; Rajapandy, V.

    2005-01-01

    We investigated the effect of nitrogen fixing Azotobacter bioinoculant on the mycelial growth and the rate of substrate utilization by Pleurotus eous. The synergistic or antagonistic role of the microorganism during dual culturing with the mushroom or the competitor molds Trichoderma viride, and Trichoderma reesi was studied. Azotobacter was inhibitory to the molds, which are competitive to the mushroom in the seed spawn substrate, but was synergistic towards the mushroom. The growth, substrate utilization potential as total nitrogen content and cellulase enzyme activities of the mushroom in the seed spawn substrate were also enhanced in the presence of the bioinoculant at lower inoculum concentrations, upto 5 ml broth culture per spawn bottle. PMID:24049469

  3. Evaluation of three gears for sampling spawning populations of rainbow trout in a large Alaskan river

    USGS Publications Warehouse

    Schwanke, C.J.; Hubert, W.A.

    2004-01-01

    Alternatives to electrofishing are needed for sampling sexually mature rainbow trout Oncorhynchus mykiss during the spawning season in large Alaskan rivers. We compared hook and line, beach seining, and actively fished gill nets as sampling tools. Beach seining and active gill netting yielded similar catch rates, length frequencies, and sex ratios of sexually mature fish. Hook-and-line sampling was less effective, with a lower catch rate and selectivity for immature fish and sexually mature females. We conclude that both beach seining and active gill netting can serve as alternatives to electrofishing for sampling sexually mature rainbow trout stocks during the spawning season in large rivers with stable spring flows and spawning areas with few snags.

  4. Dispersal of Adult Black Marlin (Istiompax indica) from a Great Barrier Reef Spawning Aggregation

    PubMed Central

    Domeier, Michael L.; Speare, Peter

    2012-01-01

    The black marlin (Istiompax indica) is one of the largest bony fishes in the world with females capable of reaching a mass of over 700 kg. This highly migratory predator occurs in the tropical regions of the Pacific and Indian Oceans, and is the target of regional recreational and commercial fisheries. Through the sampling of ichthyoplankton and ovaries we provide evidence that the relatively high seasonal abundance of black marlin off the Great Barrier Reef is, in fact, a spawning aggregation. Furthermore, through the tracking of individual black marlin via satellite popup tags, we document the dispersal of adult black marlin away from the spawning aggregation, thereby identifying the catchment area for this spawning stock. Although tag shedding is an issue when studying billfish, we tentatively identify the catchment area for this stock of black marlin to extend throughout the Coral Sea, including the waters of Papua New Guinea, the Solomon Islands, Micronesia, New Caledonia, Kiribati, Vanuatu, Fiji, Tuvalu and Nauru. PMID:22363692

  5. A simple method for in situ monitoring of water temperature in substrates used by spawning salmonids

    USGS Publications Warehouse

    Zimmerman, Christian E.; Finn, James E.

    2012-01-01

    Interstitial water temperature within spawning habitats of salmonids may differ from surface-water temperature depending on intragravel flow paths, geomorphic setting, or presence of groundwater. Because survival and developmental timing of salmon are partly controlled by temperature, monitoring temperature within gravels used by spawning salmonids is required to adequately describe the environment experienced by incubating eggs and embryos. Here we describe a simple method of deploying electronic data loggers within gravel substrates with minimal alteration of the natural gravel structure and composition. Using data collected in spawning sites used by summer and fall chum salmon Oncorhynchus keta from two streams within the Yukon River watershed, we compare contrasting thermal regimes to demonstrate the utility of this method.

  6. Evidence for spawning aggregations of the endangered Atlantic goliath grouper Epinephelus itajara in southern Brazil.

    PubMed

    Bueno, L S; Bertoncini, A A; Koenig, C C; Coleman, F C; Freitas, M O; Leite, J R; De Souza, T F; Hostim-Silva, M

    2016-07-01

    In this study, seasonal numerical abundance of the critically endangered Atlantic goliath grouper Epinephelus itajara was estimated by conducting scuba dive surveys and calculating sightings-per-unit-effort (SPUE) at three sites in southern Brazil. Seasonal differences in size and reproductive condition of captured or confiscated specimens were compared. The SPUE differed significantly with season, increasing in late spring and peaking during the austral summer months. A significant effect was observed in the number of fish relative to the lunar cycle. All females sampled during the summer were spawning capable, while all those sampled during other seasons were either regressing or regenerating. What these data strongly infer is that the E. itajara spawning aggregation sites have been located in the southern state of Paraná and the northern state of Santa Catarina and summer is the most likely spawning season. Size frequency distributions, abundance and reproductive state were estimated and correlated with environmental variables. PMID:27264779

  7. Dispersal of adult black marlin (Istiompax indica) from a Great Barrier Reef spawning aggregation.

    PubMed

    Domeier, Michael L; Speare, Peter

    2012-01-01

    The black marlin (Istiompax indica) is one of the largest bony fishes in the world with females capable of reaching a mass of over 700 kg. This highly migratory predator occurs in the tropical regions of the Pacific and Indian Oceans, and is the target of regional recreational and commercial fisheries. Through the sampling of ichthyoplankton and ovaries we provide evidence that the relatively high seasonal abundance of black marlin off the Great Barrier Reef is, in fact, a spawning aggregation. Furthermore, through the tracking of individual black marlin via satellite popup tags, we document the dispersal of adult black marlin away from the spawning aggregation, thereby identifying the catchment area for this spawning stock. Although tag shedding is an issue when studying billfish, we tentatively identify the catchment area for this stock of black marlin to extend throughout the Coral Sea, including the waters of Papua New Guinea, the Solomon Islands, Micronesia, New Caledonia, Kiribati, Vanuatu, Fiji, Tuvalu and Nauru. PMID:22363692

  8. Detecting the movement and spawning activity of bigheaded carps with environmental DNA

    USGS Publications Warehouse

    Erickson, Richard A.; Rees, Christopher B.; Coulter, Alison A.; Merkes, Christopher; McCalla, Sunnie; Touzinsky, Katherine F; Walleser, Liza R.; Goforth, Reuben R.; Amberg, Jon

    2016-01-01

    Bigheaded carps are invasive fishes threatening to invade the Great Lakes basin and establish spawning populations, and have been monitored using environmental DNA (eDNA). Not only does eDNA hold potential for detecting the presence of species, but may also allow for quantitative comparisons like relative abundance of species across time or space. We examined the relationships among bigheaded carp movement, hydrography, spawning and eDNA on the Wabash River, IN, USA. We found positive relationships between eDNA and movement and eDNA and hydrography. We did not find a relationship between eDNA and spawning activity in the form of drifting eggs. Our first finding demonstrates how eDNA may be used to monitor species abundance, whereas our second finding illustrates the need for additional research into eDNA methodologies. Current applications of eDNA are widespread, but the relatively new technology requires further refinement.

  9. Detecting the movement and spawning activity of bigheaded carps with environmental DNA.

    PubMed

    Erickson, Richard A; Rees, Christopher B; Coulter, Alison A; Merkes, Christopher M; McCalla, Sunnie G; Touzinsky, Katherine F; Walleser, Liza; Goforth, Reuben R; Amberg, Jon J

    2016-07-01

    Bigheaded carps are invasive fishes threatening to invade the Great Lakes basin and establish spawning populations, and have been monitored using environmental DNA (eDNA). Not only does eDNA hold potential for detecting the presence of species, but may also allow for quantitative comparisons like relative abundance of species across time or space. We examined the relationships among bigheaded carp movement, hydrography, spawning and eDNA on the Wabash River, IN, USA. We found positive relationships between eDNA and movement and eDNA and hydrography. We did not find a relationship between eDNA and spawning activity in the form of drifting eggs. Our first finding demonstrates how eDNA may be used to monitor species abundance, whereas our second finding illustrates the need for additional research into eDNA methodologies. Current applications of eDNA are widespread, but the relatively new technology requires further refinement. PMID:27087387

  10. Lake trout spawning habitat in the Great Lakes - a review of current knowledge

    USGS Publications Warehouse

    Marsden, J. Ellen; Casselman, John M.; Edsall, Thomas A.; Elliott, Robert F.; Fitzsimons, John D.; Horns, William H.; Manny, Bruce A.; McAughey, Scott C.; Sly, Peter G.; Swanson, Bruce L.

    1995-01-01

    We review existing information on lake trout spawning habitat, which might indicate whether habitat is now a limiting factor in lake trout reproductive success. Lake trout spawning habitat quality is defined by the presence or absence of olfactory cues for homing, reef location with respect to the shoreline, water depth, proximity to nursery areas, reef size, contour, substrate size and shape, depth of interstitial spaces, water temperature at spawning time, water quality in interstitial spaces, and the presence of egg and fry predators. Data on factors which attracted native spawners to spawning reefs are lacking, due to the absence of historic data on egg deposition. No direct evidence of egg deposition has been collected from sites deeper than 18 m. Interstitial space and, therefore, substrate size and shape, appear to be critical for both site selection by adults and protection of eggs and fry. Water quality is clearly important for egg incubation, but the critical parameters which define water quality have not yet been well determined in the field. Exposure to wave energy, dictated in part by reef location, may maintain high water quality but may also damage or dislodge eggs. The importance of olfactory cues, water temperature, and proximity to nursery habitat to spawning trout is unclear. Limited data suggest that egg and fry predators, particularly exotic species, may critically affect fry production and survival. Although availability of physical spawning habitat is probably not limiting lake trout reproduction, changes in water quality and species composition may negatively affect early life stages. This review of habitat factors that affect early life stages of lake trout suggests several priorities for research and management.

  11. Spawning Behavior and Egg Development of Aplysia kurodai Inhabiting the Coastal Waters of Jeju Island, Korea

    PubMed Central

    Lee, Chi-Hoon; Kaang, Bong-Kiun; Lee, Young-Don

    2014-01-01

    This study was investigated spawning behavior, structure of egg masses and egg development in Aplysia kurodai inhabiting the coastal waters of Jeju Island, Korea. The mating and courtship behavior of A. kurodai occurred in the form of unilateral copulating with chain formation. In chain copulation, only the first animal acted as a female; the second and succeeding animals acted as males (sperm donors) to the animals in front and as females to the animals behind. The fertilized eggs were packaged in capsules that are embedded in jelly to form a cylindrical string called an egg masses. The number of capsule per cm of the egg masses was 55 to 60 capsules and each capsule within the egg masses held 15 to 25 eggs. After spawning, the egg masses were bright yellow or orange in color. This egg masses color not changed until embryos developed into trochophore stage. Thereafter, as embryo developed from trochophore stage to veliger stage the egg masses color became brownish. The fertilized eggs were spherical, with a diameter of approximately 80±1 μm at spawning. At 5 to 6 days after spawning, the embryo developed into trochophore stage and began to rotate within the egg capsule. In the trochophore stage, the precursor of the velum, called the prototroch or prevelum, developed. At 10 days after spawning, the prevelum is transformed into the velum, and the trochophore developed into veliger stage. Between 10 to 15 days after spawning, the veligers broke out of the egg capsule, and hatched as free-swimming larvae. PMID:25949168

  12. Characterization of Atlantic cod spawning habitat and behavior in Icelandic coastal waters

    USGS Publications Warehouse

    Grabowski, Timothy B.; Boswell, Kevin M.; McAdam, Bruce J.; Wells, R. J. David; Marteinsdóttir, Gudrún

    2012-01-01

    The physical habitat used during spawning may potentially be an important factor affecting reproductive output of broadcast spawning marine fishes, particularly for species with complex, substrate-oriented mating systems and behaviors, such as Atlantic cod Gadus morhua. We characterized the habitat use and behavior of spawning Atlantic cod at two locations off the coast of southwestern Iceland during a 2-d research cruise (15–16 April 2009). We simultaneously operated two different active hydroacoustic gear types, a split beam echosounder and a dual frequency imaging sonar (DIDSON), as well as a remotely operated underwater vehicle (ROV). A total of five fish species were identified through ROV surveys: including cusk Brosme brosme, Atlantic cod, haddock Melanogrammus aeglefinus, lemon sole Microstomus kitt, and Atlantic redfish Sebastes spp. Of the three habitats identified in the acoustic surveys, the transitional habitat between boulder/lava field and sand habitats was characterized by greater fish density and acoustic target strength compared to that of sand or boulder/lava field habitats independently. Atlantic cod were observed behaving in a manner consistent with published descriptions of spawning. Individuals were observed ascending 1–5 m into the water column from the bottom at an average vertical swimming speed of 0.20–0.25 m s−1 and maintained an average spacing of 1.0–1.4 m between individuals. Our results suggest that cod do not choose spawning locations indiscriminately despite the fact that it is a broadcast spawning fish with planktonic eggs that are released well above the seafloor.

  13. Latitudinal comparison of spawning season and growth of 0-group sole, Solea solea (L.)

    NASA Astrophysics Data System (ADS)

    Vinagre, C.; Amara, R.; Maia, A.; Cabral, H. N.

    2008-07-01

    0-Group sole, Solea solea (Linnaeus, 1758) were sampled in four nursery grounds: two on the Northern French coast and two on the Portuguese coast. Juvenile sole were collected at the Vilaine estuary (Northern Bay of Biscay) in 1992, in the Authie estuary (Eastern English Channel) in 1997, and in the Douro and Tagus estuary (Northern and central Portugal, respectively) in 2005. Left lapilli otoliths were used to estimate age and investigate variability in growth rates and hatch dates. In the French study areas nursery colonisation ended in early June in the Vilaine estuary and in late June in the Authie estuary. In the Portuguese estuaries nursery colonisation ended in May in the Douro estuary and in late June in the Tagus estuary. Growth rates were higher in the Portuguese estuaries, 0.767 mm d -1 in the Tagus estuary and 0.903 mm d -1 in the Douro estuary. In the French nurseries, growth rates were estimated to be 0.473 mm d -1 in the Villaine estuary and 0.460 mm d -1 in the Authie estuary. Data on growth rates from other studies shows that growth rates are higher at lower latitudes, probably due to higher water temperature. Spawning took place between early January and early April in the Villaine estuary's coastal area in 1992. In 1997, in the Authie estuary spawning started in late January and ended in early April. On the Douro estuary's adjacent coast spawning started in mid-January and ended in late March, in 2005, while on the Tagus estuary's adjacent coast spawning started in mid-February and ended in mid-April, in the same year. Literature analysis of the spawning period of sole along a latitudinal gradient ranging from 38°N to 55°N in the Northeast Atlantic indicated that there is a latitudinal trend, in that spawning starts sooner at lower latitudes. Results support that local conditions, particularly hydrodynamics, may overrule general latitudinal trends.

  14. Evaluate the Restoration Potential of Snake River Fall Chinook Salmon Spawning Habitat, Status Report 2006.

    SciTech Connect

    Hanrahan, T.P.

    2009-01-08

    The Bonneville Power Administration (BPA) Project 2003-038-00, Evaluate the restoration potential of Snake River fall Chinook salmon spawning habitat, began in FY04 (15 December 2003) and continues into FY06. This status report is intended to summarize accomplishments during FY04 and FY05. Accomplishments are summarized by Work Elements, as detailed in the Statement of Work (see BPA's project management database PISCES). This project evaluates the restoration potential of mainstem habitats for fall Chinook salmon. The studies address two research questions: 'Are there sections not currently used by spawning fall Chinook salmon within the impounded lower Snake River that possess the physical characteristics for potentially suitable fall Chinook spawning habitat?' and 'Can hydrosystem operations affecting these sections be adjusted such that the sections closely resemble the physical characteristics of current fall Chinook salmon spawning areas in similar physical settings?' Efforts are focused at two study sites: (1) the Ice Harbor Dam tailrace downstream to the Columbia River confluence, and (2) the Lower Granite Dam tailrace. Our previous studies indicated that these two areas have the highest potential for restoring Snake River fall Chinook salmon spawning habitat. The study sites will be evaluated under existing structural configurations at the dams (i.e., without partial removal of a dam structure), and alternative operational scenarios (e.g., varying forebay/tailwater elevations). The areas studied represent tailwater habitat (i.e., riverine segments extending from a dam downstream to the backwater influence from the next dam downstream). We are using a reference site, indicative of current fall Chinook salmon spawning areas in tailwater habitat, against which to compare the physical characteristics of each study site. The reference site for tailwater habitats is the section extending downstream from the Wanapum Dam tailrace on the Columbia River. Escapement

  15. Preliminary observations on the spawning conditions of the European amphioxus (Branchiostoma lanceolatum) in captivity.

    PubMed

    Fuentes, Michael; Schubert, Michael; Dalfo, Diana; Candiani, Simona; Benito, Elia; Gardenyes, Josep; Godoy, Laura; Moret, Frederic; Illas, Margarita; Patten, Iain; Permanyer, Jon; Oliveri, Diana; Boeuf, Gilles; Falcon, Jack; Pestarino, Mario; Fernandez, Jordi Garcia; Albalat, Ricard; Laudet, Vincent; Vernier, Philippe; Escriva, Hector

    2004-07-15

    Members of the subphylum Cephalochordata, which include the genus Branchiostoma (i.e. amphioxus), represent the closest living invertebrate relatives of the vertebrates. To date, developmental studies have been carried out on three amphioxus species (the European Branchiostoma lanceolatum, the East Asian B. belcheri, and Floridian-Caribbean B. floridae). In most instances, adult animals have been collected from the field during their ripe season and allowed (or stimulated) to spawn in the laboratory. In any given year, dates of laboratory pawning have been limited by two factors. First, natural populations of these three most studied species of amphioxus are ripe, at most, for only a couple of months each year and, second, even when apparently ripe, animals spawn only at unpredictable intervals of every several days. This limited supply of living material hinders the development of amphioxus as a model system because this limitation makes it more difficult to work out protocols for new laboratory techniques. Therefore we are developing laboratory methods for increasing the number of amphioxus spawning dates per year. The present study found that a Mediterranean population of B. lanceolatum living near the Franco-Spanish border spawned naturally at the end of May and again at the end of June in 2003. Re-feeding experiments in the laboratory demonstrated that the gonads emptied at the end of May refilled with gametes by the end of June. We also found that animals with large gonads (both, obtained from the field and kept and fed at the laboratory during several weeks) could be induced to spawn in the laboratory out of phase with the field population if they were temperature shocked (spawning occurred 36 hours after a sustained increase in water temperature from 19 degrees C to 25 degrees C). PMID:15287102

  16. Discrimination among spawning aggregations of lake herring from Lake Superior using whole-body morphometric characters

    USGS Publications Warehouse

    Hoff, Michael H.

    2004-01-01

    The lake herring (Coregonus artedi) was one of the most commercially and ecologically valuable Lake Superior fishes, but declined in the second half of the 20th century as the result of overharvest of putatively discrete stocks. No tools were previously available that described lake herring stock structure and accurately classified lake herring to their spawning stocks. The accuracy of discriminating among spawning aggregations was evaluated using whole-body morphometrics based on a truss network. Lake herring were collected from 11 spawning aggregations in Lake Superior and two inland Wisconsin lakes to evaluate morphometrics as a stock discrimination tool. Discriminant function analysis correctly classified 53% of all fish from all spawning aggregations, and fish from all but one aggregation were classified at greater rates than were possible by chance. Discriminant analysis also correctly classified 66% of fish to nearest neighbor groups, which were groups that accounted for the possibility of mixing among the aggregations. Stepwise discriminant analysis showed that posterior body length and depth measurements were among the best discriminators of spawning aggregations. These findings support other evidence that discrete stocks of lake herring exist in Lake Superior, and fishery managers should consider all but one of the spawning aggregations as discrete stocks. Abundance, annual harvest, total annual mortality rate, and exploitation data should be collected from each stock, and surplus production of each stock should be estimated. Prudent management of stock surplus production and exploitation rates will aid in restoration of stocks and will prevent a repeat of the stock collapses that occurred in the middle of the 20th century, when the species was nearly extirpated from the lake.

  17. Characterization of Atlantic cod spawning habitat and behavior in Icelandic coastal waters.

    PubMed

    Grabowski, Timothy B; Boswell, Kevin M; McAdam, Bruce J; Wells, R J David; Marteinsdóttir, Guđrún

    2012-01-01

    The physical habitat used during spawning may potentially be an important factor affecting reproductive output of broadcast spawning marine fishes, particularly for species with complex, substrate-oriented mating systems and behaviors, such as Atlantic cod Gadus morhua. We characterized the habitat use and behavior of spawning Atlantic cod at two locations off the coast of southwestern Iceland during a 2-d research cruise (15-16 April 2009). We simultaneously operated two different active hydroacoustic gear types, a split beam echosounder and a dual frequency imaging sonar (DIDSON), as well as a remotely operated underwater vehicle (ROV). A total of five fish species were identified through ROV surveys: including cusk Brosme brosme, Atlantic cod, haddock Melanogrammus aeglefinus, lemon sole Microstomus kitt, and Atlantic redfish Sebastes spp. Of the three habitats identified in the acoustic surveys, the transitional habitat between boulder/lava field and sand habitats was characterized by greater fish density and acoustic target strength compared to that of sand or boulder/lava field habitats independently. Atlantic cod were observed behaving in a manner consistent with published descriptions of spawning. Individuals were observed ascending 1-5 m into the water column from the bottom at an average vertical swimming speed of 0.20-0.25 m s(-1) and maintained an average spacing of 1.0-1.4 m between individuals. Our results suggest that cod do not choose spawning locations indiscriminately despite the fact that it is a broadcast spawning fish with planktonic eggs that are released well above the seafloor. PMID:23236471

  18. Optimal reproduction in salmon spawning substrates linked to grain size and fish length

    NASA Astrophysics Data System (ADS)

    Riebe, Clifford S.; Sklar, Leonard S.; Overstreet, Brandon T.; Wooster, John K.

    2014-02-01

    Millions of dollars are spent annually on revitalizing salmon spawning in riverbeds where redd building by female salmon is inhibited by sediment that is too big for fish to move. Yet the conditions necessary for productive spawning remain unclear. There is no gauge for quantifying how grain size influences the reproductive potential of coarse-bedded rivers. Hence, managers lack a quantitative basis for optimizing spawning habitat restoration for reproductive value. To overcome this limitation, we studied spawning by Chinook, sockeye, and pink salmon (Oncorhynchus tshawytscha, O. nerka, and O. gorbuscha) in creeks and rivers of California and the Pacific Northwest. Our analysis shows that coarse substrates have been substantially undervalued as spawning habitat in previous work. We present a field-calibrated approach for estimating the number of redds and eggs a substrate can accommodate from measurements of grain size and fish length. Bigger fish can move larger sediment and thus use more riverbed area for spawning. They also tend to have higher fecundity, and so can deposit more eggs per redd. However, because redd area increases with fish length, the number of eggs a substrate can accommodate is maximized for moderate-sized fish. This previously unrecognized tradeoff raises the possibility that differences in grain size help regulate river-to-river differences in salmon size. Thus, population diversity and species resilience may be linked to lithologic, geomorphic, and climatic factors that determine grain size in rivers. Our approach provides a tool for managing grain-size distributions in support of optimal reproductive potential and species resilience.

  19. Quantity, structure, and habitat selection of natural spawning reefs by walleyes in a north temperate lake: A multiscale analysis

    USGS Publications Warehouse

    Raabe, Joshua K.; Bozek, Michael A.

    2012-01-01

    Spawning habitat, the cornerstone of self-sustaining, naturally reproducing walleyeSander vitreus populations, has received limited quantitative research. Our goal was to quantitatively describe the structure and quantity of natural walleye spawning habitat and evaluate potential selection of habitat in Big Crooked Lake, Wisconsin. In 2004 and 2005, we located and delineated walleye egg deposition polygons through visual snorkel and scuba surveys. We also delineated recently deposited, adhesive egg patches daily along one spawning reef in 2005. To determine habitat selection, we quantified and compared spawning and lakewide available habitat at different scales. In both years, walleyes used similar spawning habitat, including three geomorphic types: linear shorelines, a point bar, and an island. Walleyes used only 14% of the entire lake shoreline and 39% of the shoreline comprised of gravel (6.4–76.0 mm), cobble (76.1–149.9 mm), or coarser substrates for spawning in 2005, indicating selection of specific spawning habitat. Lakewide, walleyes spawned close to shore (outer egg deposition polygon boundary mean distance = 2.7 m), in shallow water (outer egg deposition polygon boundary mean depth = 0.3 m), and over gravel substrate (percent coverage mean = 64.3) having low embeddedness (mean = 1.30). Our best nearshore (0–13-m) resource selection function predicted an increase in the relative probability of egg deposition with the increasing abundance of gravel, cobble, and rubble (150.0–303.9-mm) substrates and a decrease with increasing distance from shore and water depth (89.9% overall correct classification). Adhesive egg patches confirmed that walleyes actively chose nearshore, shallow-water, and coarse-substrate spawning habitat. The quantitative habitat information and predictive models will assist biologists in developing walleye spawning reef protection strategies and potentially aid in designing and evaluating artificial spawning reefs.

  20. Effects of arabinoxylan-oligosaccharides (AXOS) on juvenile Siberian sturgeon (Acipenser baerii) performance, immune responses and gastrointestinal microbial community.

    PubMed

    Geraylou, Zahra; Souffreau, Caroline; Rurangwa, Eugene; D'Hondt, Sofie; Callewaert, Lien; Courtin, Christophe M; Delcour, Jan A; Buyse, Johan; Ollevier, Frans

    2012-10-01

    Arabinoxylan-oligosaccharides (AXOS) are a newly discovered class of candidate prebiotics that exert different properties depending on their structure. In this study the effects of two different structures of AXOS, namely AXOS-32-0.30 (average degree of polymerization: 32, average degree of substitution: 0.30) and AXOS-3-0.25, were investigated on growth performance, immune responses, gut microbial fermentation and gut bacterial composition of juvenile Siberian sturgeon (Acipenser baerii). After a two weeks acclimation, fish (25.9 ± 0.9 g) were distributed over 24 aquariums (8 replicates per treatment) and fed a control diet or a diet containing 2% AXOS-32-0.30 or AXOS-3-0.25 for 12 weeks. Growth performance and feed utilization tend to improve in sturgeon fed on diets supplemented with AXOS-32-0.30, however not significant. Survival was high in all groups. Both AXOS preparations significantly enhanced the phagocytic activity of fish macrophages compared to the control group, while the alternative haemolytic complement activity and total serum peroxidase content improved only in the group fed AXOS-32-0.30 (P < 0.05). The lysozyme activity was not affected by AXOS addition. Simultaneously, the amount of short-chain fatty acids (SCFAs) was highest in the hind gut of sturgeon fed AXOS-32-0.30. The concentrations of acetate, butyrate and total SCFAs in fish fed AXOS-32-0.30 was significantly higher than in the groups fed the control diet or AXOS-3-0.25. Study of the bacterial community in the sturgeon hindgut using PCR-denaturing gradient gel electrophoresis (PCR-DGGE) revealed that both preparations of AXOS induced changes in the bacterial composition. According to redundancy analysis (RDA), hindgut microbiota of each treatment group clustered apart from one another (P = 0.001). DNA sequencing of the dominant DGGE bands recovered from the different treatments showed that AXOS mainly stimulated the growth of lactic acid bacteria and Clostridium sp., with more

  1. Effects of diazinon on adaptation to sea-water by the endangered Persian sturgeon, Acipenser persicus, fingerlings.

    PubMed

    Hajirezaee, Saeed; Mirvaghefi, Ali Reza; Farahmand, Hamid; Agh, Naser

    2016-11-01

    To replenish the depleting populations of sturgeon fishes especially Persian sturgeon, Acipenser persicus in the Caspian Sea, millions of Persian sturgeon fingerlings are farmed through artificial propagation and released into the Iranian river estuaries annually. Fish osmoregulation is a vital physiological process that can be affected during the release. Many Iranian river estuaries are under the influence of pesticides originating from farming activities that may affect osmoregulation. In this study, Persian sturgeon fingerlings were exposed to sublethal concentrations (0, 0.18, 0.54, 0.9mgL(-)(1)) of diazinon for 96h (short-term trial) and 12 days (long-term trial) in fresh water (FW) and then fish were exposed in brackish water (BW) for 24h. After 96h and 12 days of exposure in FW, the lower levels of plasma triidothyronine (T3), thyroxine (T4), Na(+), Cl(-), K(+), gill Na(+)/K(+)- ATPase activity and number of chloride cells were observed in exposed fish (0.54 and 0.9mgL(-)(1) diazinon) compared to control group and 0.18mgL(-)(1) diazinon treatment. Also, higher levels of plasma cortisol (except 0.18mgL(-)(1) diazinon treatment in long-term trial) were observed in diazinon exposed fish compared to control group. However, gill Na(+)/K(+)-ATPase activity and the number of chloride cells were higher in fingerlings exposed to diazinon compared than control. When fish were exposed in BW for 24h, the following changes occurred: (a) in short-term trial: increases in cortisol and Cl(-) levels (0.54mgL(-)(1) diazinon ), Na(+) (0.9mgL(-)(1) diazinon ) and gill Na(+)/K(+)-ATPase activity (0.18mgL(-)(1) diazinon ). In control group, cortisol, T4, Na(+), gill Na(+)/K(+)-ATPase activity and the number of chloride cells increased significantly. (b) In long-term trial: increases in K(+) levels in fish exposed to 0.9mgL(-)(1) diazinon, Na+ in all diazinon concentrations and decreases in chloride cells number in fish exposed to 0.18mgL(-)(1) diazinon. In control group

  2. Striped Bass Spawning in Non-Estuarine Portions of the Savannah River

    SciTech Connect

    Martin, D.; Paller, M.

    2007-04-17

    Historically, the estuarine portions of the Savannah River have been considered to be the only portion of the river in which significant amounts of striped bass (Morone saxatilis) spawning normally occur. A reexamination of data from 1983 through 1985 shows a region between River Kilometers 144 and 253 where significant numbers of striped bass eggs and larvae occur with estimated total egg production near that currently produced in the estuarine reaches. It appears possible that there are two separate spawning populations of striped bass in the Savannah River.

  3. Predator avoidance during reproduction: diel movements by spawning sockeye salmon between stream and lake habitats.

    PubMed

    Bentley, Kale T; Schindler, Daniel E; Cline, Timothy J; Armstrong, Jonathan B; Macias, Daniel; Ciepiela, Lindsy R; Hilborn, Ray

    2014-11-01

    Daily movements of mobile organisms between habitats in response to changing trade-offs between predation risk and foraging gains are well established; however, less in known about whether similar tactics are used during reproduction, a time period when many organisms are particularly vulnerable to predators. We investigated the reproductive behaviour of adult sockeye salmon (Oncorhynchus nerka) and the activity of their principal predator, brown bears (Ursus arctos), on streams in south-western Alaska. Specifically, we continuously monitored movements of salmon between lake habitat, where salmon are invulnerable to bears, and three small streams, where salmon spawn and are highly vulnerable to bears. We conducted our study across 2 years that offered a distinct contrast in bear activity and predation rates. Diel movements by adult sockeye salmon between stream and lake habitat were observed in 51.3% ± 17.7% (mean ± SD) of individuals among years and sites. Fish that moved tended to hold in the lake for most of the day and then migrated into spawning streams during the night, coincident with when bear activity on streams tended to be lowest. Additionally, cyclic movements between lakes and spawning streams were concentrated earlier in the spawning season. Individuals that exhibited diel movements had longer average reproductive life spans than those who made only one directed movement into a stream. However, the relative effect was dependent on the timing of bear predation, which varied between years. When predation pressure primarily occurred early in the spawning run (i.e., during the height of the diel movements), movers lived 120-310% longer than non-movers. If predation pressure was concentrated later in the spawning run (i.e. when most movements had ceased), movers only lived 10-60% longer. Our results suggest a dynamic trade-off in reproductive strategies of sockeye salmon; adults must be in the stream to reproduce, but must also avoid predation long

  4. Consumption of coral propagules after mass spawning enhances larval quality of damselfish through maternal effects.

    PubMed

    McCormick, Mark I

    2003-06-01

    The synchronized spawning of corals in many parts of the Indo-Pacific represents a huge injection of biological material into the waters around reefs. Much of this material is consumed by fishes and filter-feeding invertebrates in the 5 or so days following spawning. The present study is the first to document the effect of the consumption of coral propagules on a population of facultatively planktivorous fish and the transference of physiological condition across generations. The study compares two populations of the damselfish Pomacentrus amboinensis that fed to differing degrees on coral propagules for 5 days after the annual mass spawning of corals at Lizard Island, Great Barrier Reef, Australia. Wind blew coral slicks over the outer lagoon to the inner lagoon some 1.5 km away. While coral propagules were abundant in the water column in the windward location, they were scarce by the time the water mass reached the inner lagoon. Behavioral observations 2-5 days after coral spawning showed that a significantly higher proportion of P. amboinensis was feeding on coral propagules in the windward location than in the inner lagoon location. Windward location females consumed coral propagules almost exclusively and had fuller guts than females from the inner lagoonal location. Five days after the mass coral spawning, windward location females had a higher condition factor and a larger liver mass relative to body mass compared to females within the inner lagoon or females from both locations 2 months later. Fish eggs laid by the windward location females soon after coral spawning yielded larvae that had 25% larger yolk sacs and 100% larger oil globules than did larvae produced from the females from the inner lagoon location, or larvae produced at either location prior to or well after coral spawning in 2 previous years. Larger yolk sacs and oil globules have been shown to have direct survival benefits in the transition from endogenous to exogenous feeding. A feeding

  5. Steelhead Spawning Surveys Near Locke Island, Hanford Reach of the Columbia River

    SciTech Connect

    Geist,; Mueller, RP

    1999-10-19

    In 1997, the National Marine Fisheries Service (NMFS) listed upper Columbia River steelhead trout (Oncorhynchus znykiss) as endangered. This action affected management of land-use activities along and within the Hanford Reach of the Columbia River, which flows through the U.S. Department of Energy (DOE) Hanford Site. Steelhead covered in this listing include all naturally spawned populations of steel-head and their progeny in streams in the Columbia River Basin upstream from the Yakima River to the United States/Canada border. The NMFS has identified a general listing of activities that could potentially result in harm to steelhead (62 FR 43937, August 18, 1997). One of these concerns includes land-use changes resulting in mass wasting or surface erosion. Landslide activity along the White Bluffs on the east ,side of Locke Island has redirected river flow into the island where substantial erosion has occurred. This erosion has exposed important anthropological and archaeological resources that were previously buried on the island. The DOE is working with affected tribes and other agencies to develop a plan for addressing the erosion of Locke Island. As part of this effort, the U.S. Army Corps of Engineers has prepared an assessment of potential alternatives to stabilize the erosion, including a no-action alternative. Steelhead historically spawned in the vicinity of Locke Island, but recent information on the occurrence of steelhead spawning or availability of spawning habitat was lacking. Therefore, the purpose of this study was to determine if steelhead spawned in the vicinity of Locke Island erosion and to evaluate the composition of substrate in the affected area. Surveys to document the occurrence of steelheads redds were conducted in Spring 1999. The surveys were conducted from the air as well as with the use of an underwater video camera. Neither aerial nor underwater surveys documented steelhead spawning within the survey area. Habitat surveys were

  6. Communication: GAIMS—Generalized Ab Initio Multiple Spawning for both internal conversion and intersystem crossing processes

    NASA Astrophysics Data System (ADS)

    Curchod, Basile F. E.; Rauer, Clemens; Marquetand, Philipp; González, Leticia; Martínez, Todd J.

    2016-03-01

    Full multiple spawning is a formally exact method to describe the excited-state dynamics of molecular systems beyond the Born-Oppenheimer approximation. However, it has been limited until now to the description of radiationless transitions taking place between electronic states with the same spin multiplicity. This Communication presents a generalization of the full and ab initio multiple spawning methods to both internal conversion (mediated by nonadiabatic coupling terms) and intersystem crossing events (triggered by spin-orbit coupling matrix elements) based on a spin-diabatic representation. The results of two numerical applications, a model system and the deactivation of thioformaldehyde, validate the presented formalism and its implementation.

  7. Migration and spawning of radio-tagged zulega Prochilodus argenteus in a dammed Brazilian river

    USGS Publications Warehouse

    Godinho, Alexandre L.; Kynard, B.

    2006-01-01

    It is difficult for agencies to evaluate the impacts of the many planned dams on Sa??o Francisco River, Brazil, migratory fishes because fish migrations are poorly known. We conducted a study on zulega Prochilodus argenteus, an important commercial and recreational fish in the Sa??o Francisco River, to identify migrations and spawning areas and to determine linear home range. During two spawning seasons (2001-2003), we radio-tagged fish in three main-stem reaches downstream of Tre??s Marias Dam (TMD), located at river kilometer (rkm) 2,109. We tagged 10 fish at Tre??s Marias (TM), which is 5 km downstream of TMD; 12 fish at Pontal, which is 28 km downstream of TMD and which includes the mouth of the Abaete?? River, and 10 fish at Cilga, which is 45 km downstream of TMD. Late-stage (ripe) adults tagged in each area during the spawning season remained at or near the tagging site, except for four Cilga fish that went to Pontal and probably spawned. The Pontal area at the Abaete?? River mouth was the most important spawning site we found. Prespawning fish moved back and forth between main-stem staging areas upstream of the Abaete?? River mouth and Pontal for short visits. These multiple visits were probably needed as ripe fish waited for spawning cues from a flooding Abaete?? River. Some fish homed to prespaw ning staging areas, spawning areas, and nonspawning areas. The migratory style of zulega was dualistic, with resident and migratory fish. Total linear home range was also dualistic, with small (<26-km) and large (53-127-km) ranges. The locations of spawning areas and home ranges suggest that the Pontal group (which includes Cilga fish) is one population that occupies about 110 km. The Pontal population overlaps a short distance with a population located downstream of Cilga. Movements of late-stage TM adults suggest that the TM group is a separate population, possibly with connections to populations upstream of TMD. ?? Copyright by the American Fisheries Society

  8. A New Tool for Assessing Salmon Spawning Substrates in Coarse-Bedded Rivers

    NASA Astrophysics Data System (ADS)

    Riebe, C. S.; Overstreet, B. T.; Wooster, J. K.; Ligon, F. K.

    2010-12-01

    Millions of dollars are spent annually on revitalizing salmon spawning in anthropogenically coarsened riverbeds. Restoration strategies typically involve gravel augmentation—the addition of “spawning-sized” particles at sites that are too coarse but otherwise seem suitable for salmon spawning. However, managers lack a quantitative basis for such strategies, because the influence of coarse sediment on salmon spawning has not been systematically quantified. To address this gap, we measured grain sizes and the areal extent of spawning across a series of rivers where redd-building by chinook and pink salmon (Oncorhynchus tshawytscha and O. gorbuscha) appears to be affected by coarse sediment. Our data from spawning redds show that, for each salmon run, the mass of the largest particle moved by female fish increases with the square of flow velocity and thus is proportional with shear stress, consistent with first principles from fluid mechanics. Furthermore, across species and runs, which range in average female fish length from 450 to 820 mm in this study, we find that the mass of the largest particle moved increases with the square root of fish mass; thus we infer that, on a mass-per-mass basis, smaller fish are able to move bigger particles. Our data show that female salmon can often move particles that are bigger than the median particle size of the bed; this adds fresh support to recent revelations that, when salmon spawn en masse, they can mobilize sediment and modify bed-surface textures at rates that are commensurate with sediment transport at bankfull discharge. Our analysis suggests that spawning use of riverbeds is limited by percent coverage of particles that are too coarse for fish to move. We present a power-law regression model for predicting immovable particle coverage from fish length and both D50 and D84, two oft-measured indices of bed-surface grain-size distributions. Across the data considered here, our model predicts coverage by immovable

  9. Distribution of spawning activity by anadromous fishes in an atlantic slope drainage after removal of a low-head dam

    USGS Publications Warehouse

    Burdick, S.M.; Hightower, J.E.

    2006-01-01

    In 1998, the Quaker Neck Dam was removed from the Neuse River near Goldsboro, North Carolina, restoring access to more than 120 km of potential main-stem spawning habitat and 1,488 km of potential tributary spawning habitat to anadromous fishes. We used plankton sampling and standardized electrofishing to examine the extent to which anadromous fishes utilized this restored spawning habitat in 2003 and 2004. Evidence of spawning activity was detected upstream of the former dam site for three anadromous species: American shad Alosa sapidissima, hickory shad A. mediocris, and striped bass Morone saxatilis. The percentages of eggs and larvae collected in the restored upstream habitat were greater in 2003, when spring flows were high, than in 2004. River reaches where spawning occurred were estimated from egg stage and water velocity data. Spawning of American shad and striped bass occurred primarily in main-stem river reaches that were further upstream during the year of higher spring flows. Hickory shad generally spawned in downstream reaches and in tributaries above and below the former dam site. These results demonstrate that anadromous fishes will take advantage of upper basin spawning habitat restored through dam removal as long as instream flows are adequate to facilitate upstream migration.

  10. INDUCTION OF MATURATION AND SPAWNING OF PINK SHRIMP, PENAEUS DUORARUM, BY CHANGING WATER TEMPERATURE, AND SURVIVAL OF GROWTH OF YOUNG

    EPA Science Inventory

    Maturation, mating, and spawning of pink shrimp, Panaeus duorarum, are described. hree temperature cycles over 130 days produced three separate periods of maturation and spawning within 7 to 14 days after the water temperature increased from the minimum of 20.5 +/- 0.5 degrees C ...

  11. Organohalogen concentrations and feeding status in Atlantic salmon (Salmo salar L.) of the Baltic Sea during the spawning run.

    PubMed

    Vuorinen, Pekka J; Kiviranta, Hannu; Koistinen, Jaana; Pöyhönen, Outi; Ikonen, Erkki; Keinänen, Marja

    2014-01-15

    Changes in the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Baltic salmon muscle were studied during the spawning migration from the southern Baltic Sea to rivers flowing into the northern Gulf of Bothnia and during the spawning period. The aim was to obtain information to facilitate the arrangement of salmon fisheries such that the human dioxin intake is taken into account. The EC maximum allowable total toxic equivalent concentration (WHO-TEQPCDD/F+PCB) was exceeded in the muscle of the majority of the migrating salmon, except in the Baltic Proper. The fresh-weight-based concentrations of all toxicant groups in salmon tended to be the lowest in the Baltic Proper and the Northern Quark, and all toxicant concentrations, except PCDDs and PCDFs, were significantly higher in the spawning salmon than in the salmon caught during the spawning run. The fat content of the salmon muscle decreased by 60% during the spawning run, and the lipid-based total toxicant concentrations were consequently 4.2-6.2 times higher during the spawning period than during the spawning migration. However, the toxicants were concentrated just before spawning, and thus there is no essential difference related to whether the salmon are caught in the sea or the recreational river fishery. PMID:24056447

  12. Effects of diets with fish meal and oil replaced with plant production on spawning in Rainbow Trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To determine the effects of plant protein and oils on spawning rainbow trout an experiment was set up to examine 3 distinct families fed the following diets: 1) fish meal and fish oil; 2) plant meal and fish oil; 3) plant meal and plant oil. The fish were fed the diets for one year through spawning....

  13. Evidence for skipped spawning in a potamodromous cyprinid, humpback chub (Gila cypha), with implications for demographic parameter estimates

    USGS Publications Warehouse

    Pearson, Kristen Nicole; Kendall, William; Winkelman, Dana L.; Persons, William R.

    2015-01-01

    Our findings reveal evidence for skipped spawning in a potamodromous cyprinid, humpback chub (HBC; Gila cypha  ). Using closed robust design mark-recapture models, we found, on average, spawning HBC transition to the skipped spawning state () with a probability of 0.45 (95% CRI (i.e. credible interval): 0.10, 0.80) and skipped spawners remain in the skipped spawning state () with a probability of 0.60 (95% CRI: 0.26, 0.83), yielding an average spawning cycle of every 2.12 years, conditional on survival. As a result, migratory skipped spawners are unavailable for detection during annual sampling events. If availability is unaccounted for, survival and detection probability estimates will be biased. Therefore, we estimated annual adult survival probability (S), while accounting for skipped spawning, and found S remained reasonably stable throughout the study period, with an average of 0.75 ((95% CRI: 0.66, 0.82), process varianceσ2 = 0.005), while skipped spawning probability was highly dynamic (σ2 = 0.306). By improving understanding of HBC spawning strategies, conservation decisions can be based on less biased estimates of survival and a more informed population model structure.

  14. Interdisciplinary Adventures in Perceptual Ecology

    NASA Astrophysics Data System (ADS)

    Bocast, Christopher S.

    A portfolio dissertation that began as acoustic ecology and matured into perceptual ecology, centered on ecomusicology, bioacoustics, and translational audio-based media works with environmental perspectives. The place of music in Western eco-cosmology through time provides a basis for structuring an environmental history of human sound perception. That history suggests that music may stabilize human mental activity, and that an increased musical practice may be essential for the human project. An overview of recent antecedents preceding the emergence of acoustic ecology reveals structural foundations from 20th century culture that underpin modern sound studies. The contextual role that Aldo Leopold, Jacob von Uexkull, John Cage, Marshall McLuhan, and others played in anticipating the development of acoustic ecology as an interdiscipline is detailed. This interdisciplinary aspect of acoustic ecology is defined and defended, while new developments like soundscape ecology are addressed, though ultimately sound studies will need to embrace a broader concept of full-spectrum "sensory" or "perceptual" ecology. The bioacoustic fieldwork done on spawning sturgeon emphasized this necessity. That study yielded scientific recordings and spectrographic analyses of spawning sounds produced by lake sturgeon, Acipenser fulvescens, during reproduction in natural habitats in the Lake Winnebago watershed in Wisconsin. Recordings were made on the Wolf and Embarrass River during the 2011-2013 spawning seasons. Several specimens were dissected to investigate possible sound production mechanisms; no sonic musculature was found. Drumming sounds, ranging from 5 to 7 Hz fundamental frequency, verified the infrasonic nature of previously undocumented "sturgeon thunder". Other characteristic noises of sturgeon spawning including low-frequency rumbles and hydrodynamic sounds were identified. Intriguingly, high-frequency signals resembling electric organ discharges were discovered. These

  15. Differential expression of three types of gonadotropin-releasing hormone genes during the spawning season in grass puffer, Takifugu niphobles.

    PubMed

    Shahjahan, Md; Hamabata, Tomoko; Motohashi, Eiji; Doi, Hiroyuki; Ando, Hironori

    2010-05-15

    Grass puffer, Takifugu niphobles, has unique spawning behavior; spawning occurs on beach only for several days around new moon and full moon from spring to early summer. To investigate the role of gonadotropin-releasing hormone (GnRH) in the reproductive function, genes encoding three types of GnRHs, namely seabream GnRH (sbGnRH), chicken GnRH-II (cGnRH-II) and salmon GnRH (sGnRH), were cloned and changes in their mRNA amounts were examined over the spawning season. In addition, changes in the pituitary gonadotropin subunit mRNAs and the plasma steroid hormones were examined over the spawning season. Fishes were assessed at four reproductive stages, i.e., in December (early maturation), in April (maturing), in May (spawning), and in July (post-spawning). Moreover, spawning fish just after releasing eggs and sperm were taken at a spawning bed. The amounts of sbGnRH mRNA were substantially elevated in May and the spawning fish in both sexes, concomitant with considerable elevations of follicle-stimulating hormone and luteinizing hormone beta subunit mRNAs and plasma estradiol-17beta (E(2)) and testosterone (T) levels. There were strong positive correlations between the sbGnRH mRNA and the plasma E(2) and T levels over the spawning season in both sexes. The amounts of cGnRH-II mRNA showed no noticeable changes except for an increase in the post-spawning females. The amounts of sGnRH mRNA in the males were significantly increased in May, but they were low in the spawning males. In the females, sGnRH mRNA increased from the maturing stage and reached a maximum in the post-spawning stage, in which a positive correlation with the plasma cortisol levels was observed. These specific changes suggest that the expression of three types of GnRH genes is differentially regulated during the spawning season, and sex steroids may be important for the differential expression of GnRH genes. PMID:20138178

  16. Bioaccumulation of Zn, Cu and Mn in the caviar and muscle of Persian sturgeon (Acipenser persicus) from the Caspian Sea, Iran.

    PubMed

    Mashroofeh, Abdulreza; Bakhtiari, Alireza Riyahi; Pourkazemi, Mohammad

    2012-12-01

    Concentrations of Zn, Cu and Mn were examined in caviar and muscle of the Persian sturgeon (Acipenser persicus) collected from coastal waters of south Caspian Sea during March and April, 2011. Mean Zn, Cu and Mn concentrations in caviar samples were 21.48, 2.05 and 1.66 μg g(-1) wet weight basis, respectively. The mean Zn, Cu and Mn concentrations in muscle tissues were 7.49, 1.00 and 0.34 μg g(-1) wet weight basis, respectively. The mean concentrations of Zn and Cu in caviar and muscle samples were under the permissible limits proposed by the United Kingdom's Ministry of Agriculture, Fisheries and Food (2000). PMID:23080537

  17. Effect of dietary macronutrient proportion on intermediate metabolism and oxidative status in sturgeon (Acipenser naccarii) and trout (Oncorhynchus mykiss): comparative study.

    PubMed

    Furné, M; García-Gallego, M; Hidalgo, M C; Sanz, A

    2016-08-01

    Three isoenergetic diets varying the proportion of dietary energy supplied by each of the macronutrients (carbohydrate, lipid, or protein) were delivered, to farmed sturgeon (Acipenser naccarii) and trout (Oncorhynchus mykiss), to test the possible effects on the intermediate metabolism and oxidative status in liver, white muscle, and heart. In trout, there is an adaptive metabolic response to an increase in lipids and carbohydrates in the diet. However, this does not happen in the sturgeon. These differences may be due to different dietary habits of both species. In terms of oxidative status, only the liver displayed oxidative stress in both species, showing an increase in the lipid peroxidation and antioxidant enzyme activities after feeding with the high-lipid and high-protein diet. PMID:26970754

  18. Ecological relationship between freshwater sculpins (Genus cottus) and beach-spawning sockeye salmon (Oncorhynchus nerka) in Iliamna Lake, Alaska

    USGS Publications Warehouse

    Foote, C.J.; Brown, G.S.

    1998-01-01

    The interaction between two sculpin species, Cottus cognatus and Cottus aleuticus, and island beach spawning sockeye salmon (Oncorhynchus nerka) was examined in Iliamna Lake, Alaska. We conclude that sculpins actively move to specific spawning beaches and that the initiation of their movements precedes the start of spawning. Sculpin predation on sockeye eggs is positively dependent on sculpin size and on the state of the eggs (fresh versus water hardened), with the largest sculpins able to consume nearly 50 fresh eggs at a single feeding and 130 over a 7-day period. The number of sculpins in sockeye nests is greatest at the beginning of the spawning run, lowest in the middle, and high again at the end, with peak numbers of over 100 sculpins per nest (1 m2). We discuss the results in terms of energy flow of marine-derived nutrients into an oligotrophic system and in terms of the coevolution of sockeye spawning behavior and the predatory behavior of sculpins.

  19. Salmon spawning habitat rehabilitation on the Merced River, California: An evaluation of project planning and performance

    SciTech Connect

    Kondolf, G.M.; Vick, J.C.; Ramirez, T.M.

    1996-11-01

    From 1986 to 1995, over US$2.5 million has been spent or allocated for projects to modify channel conditions to improve spawning habitat for chinook salmon Oncorhynchus tshawytscha in the Merced. Tuolumne, and Stanislaus rivers, tributaries to the San Joaquin River, California. The authors evaluated the planning, design and performance of the Riffle 1B reconstruction on the Merced River. This typical of the nine individual riffle reconstructions completed to date. involving excavation of the existing channel bed (here, to 0.6 m) and back-filling with smaller gravels believed to be more suitable for salmon spawning. Project documents were reviewed, agency staff interviewed, and field surveys conducted to document channel conditions in 1994 for comparison with the project as constructed in 1990. The project planning and design did not consider the site`s geomorphic context nor processes of erosion and sediment transport under the current flow regime. As a consequence, spawning-sized gravel placed in the channel was scoured and transported through the site at a flow with a return period of 1.5 years. The need for spawning habitat enhancement in the Merced River is questionable, but if such projects are to be built, the authors recommend that the project planning and design consider the site`s geomorphic context and acknowledge the need for and provide funds for project maintenance, and that the performance of completed projects be systematically monitored and evaluated. 32 refs., 8 figs., 1 tab.

  20. Spatial and temporal characteristics of grouper spawning aggregations in marine protected areas in Palau, western Micronesia

    NASA Astrophysics Data System (ADS)

    Golbuu, Yimnang; Friedlander, Alan M.

    2011-04-01

    In Palau, Ngerumekaol and Ebiil Channels are spawning aggregation sites that have been protected from fishing since 1976 and 2000, respectively. Groupers and other targeted fisheries species were monitored monthly over a 1.5 year period at these two spawning aggregations and two nearby exploited reference sites where grouper formerly aggregated to spawn. At the protected aggregation sites, three grouper species ( Plectropomus areolatus, Epinephelus polyphekadion, and Epinephelus fuscoguttatus) accounted for 78% of the abundance and 85% of the biomass of all resource species surveyed but comprised <1% of the total abundance and biomass at reference sites not protected from fishing that formally harbored spawning aggregations. Abundance and biomass of grouper species pooled were 54% and 72% higher, respectively, at Ngerumekaol compared to Ebiil. Comparisons with data from the same locations in 1995-1996 showed order of magnitude declines in abundance of E. polyphekadion at both locations. The lower numbers of E. fuscoguttatus and the near absence of E. polyphekadion at Ebiil may reflect the effects of previous and current overexploitation.

  1. Linking air-sea energy exchanges and European anchovy potential spawning ground

    NASA Astrophysics Data System (ADS)

    Grammauta, R.; Molteni, D.; Basilone, G.; Guisande, C.; Bonanno, A.; Aronica, S.; Giacalone, G.; Fontana, I.; Zora, M.; Patti, B.; Cuttitta, A.; Buscaino, G.; Sorgente, R.; Mazzola, S.

    2008-10-01

    The physical and chemical processes of the sea greatly affect the reproductive biology of fishes, mainly influencing both the numbers of spawned eggs and the survivorship of early stages up to the recruitment period. In the central Mediterranean, the European anchovy constitutes one of the most important fishery resource. Because of its short living nature and of its recruitment variability, associated to high environmental variability, this small pelagic species undergo high interannual fluctuation in the biomass levels. Despite several efforts were addressed to characterize fishes spawning habitat from the oceanographic point of view, very few studies analyze the air-sea exchanges effects. To characterize the spawning habitat of these resources a specific technique (quotient rule analysis) was applied on air-sea heat fluxes, wind stress, sea surface temperature and turbulence data, collected in three oceanographic surveys during the summer period of 2004, 2005 and 2006. The results showed the existence of preferred values in the examined physical variables, associated to anchovy spawning areas. Namely, for heat fluxes the values were around -40 W/m2, for wind stress 0.04-0.11 N/m2, for SST 23°C, and 300 - 500 m3s-3 for wind mixing. Despite the obtained results are preliminary, this is the first relevant analysis on the air-sea exchanges and their relationship with the fish biology of pelagic species.

  2. Evaluation of a GnRh-II analog as a spawning aid in catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effectiveness of three different analogs of gonadotropin-releasing hormone (GnRH) to induce spawning in female channel catfish, Ictalurus punctatus, was evaluated head to head in a blind study. Two of those analogs are currently used under INAD by the catfish industry, mGnRH Ia (D-Ala6, Pro9-NHe...

  3. Effects of habitat quality and ambient hyporheic flows on salmon spawning site selection

    NASA Astrophysics Data System (ADS)

    Benjankar, Rohan; Tonina, Daniele; Marzadri, Alessandra; McKean, Jim; Isaak, Daniel J.

    2016-05-01

    Understanding the role of stream hydrologic and morphologic variables on the selection of spawning sites by salmonid fishes at high resolution across broad scales is needed for effective habitat restoration and protection. Here we used remotely sensed meter-scale channel bathymetry for a 13.5 km reach of Chinook salmon spawning stream in central Idaho to describe habitat quality and set boundary conditions for a two-dimensional surface water model coupled with a three-dimensional hyporheic flux model. Metrics describing ambient hyporheic flow intensity and habitat quality, which is quantified as a function of stream hydraulics and morphology, were compared to the locations of nests built by female salmon. Nest locations were predicted most accurately by habitat quality followed by channel morphology (i.e., riffles location). As a lesser degree than habitat quality, water surface curvature was also a good indicator of spawning location because its intensity can identify riffle morphology. The ambient hyporheic flow predicted at meter-scale resolution was not a strong predictor of redd site selection. Furthermore, the study suggests direct morphological measurements obtained from easily measured channel bathymetry data could enable effective and rapid assessments of salmon spawning channels across broad areas.

  4. REPRODUCTIVE ECOLOGY AND SPAWNING PERIODICITY OF THE ATLANTIC SILVERSIDE, 'MENIDIA MENIDIA' (PISCES: ATHERINIDAE)

    EPA Science Inventory

    The reproduction ecology and spawning periodicity of the Atlantic silverside, Menidia menidia, living in the North Edisto River estuary, South Carolina, was studied at two sites, Bears Bluff and the Point of Pines, during the spring and summer of 1976, 1977, and 1978. A specific ...

  5. LABORATORY OF SPAWNING OF TOPSMELT ATHERINOPS AFFINIS, WITH NOTES ON CULTURE AND GROWTH OF LARVAE.

    EPA Science Inventory

    Topsmelt, Atherinops affinis, were spawned repeatedly in the laboratory during May-July, 1989. eriodic "temperature spike" from the holding temperature of -18 degrees C, up to -20.5 degrees C, introduced at 7 to 9 day intervals, resulted in maximum production of viable embryos on...

  6. Year-round reproduction and induced spawning of Chinese amphioxus, Branchiostoma belcheri, in laboratory.

    PubMed

    Li, Guang; Shu, ZongHuang; Wang, Yiquan

    2013-01-01

    Amphioxus is a best candidate for studying the evolutionary and developmental mechanisms of vertebrates, because of its vertebrate-like but much simpler morphology, embryonic development and genome structure. Producing live amphioxus embryos throughout the year is an ideal for comparative evolution and developmental studies. However, all amphioxus species have distinct breeding seasons in the wild and laboratory. We recently found that Chinese amphioxus B. belcheri could reproduce repeatedly beyond its natural breeding season when reared under proper conditions. In this study, we were able to extend further and produce embryos throughout the year from October 2011 to October 2012. We found all examined animals had spawned repeatedly during the examined period. In addition, both lancelets B. belcheri and B. japonicum could be induced to spawn by heat-shock method, although the induced spawning efficiency was not as high as that observed in the European lancelet. In general, we have succeeded in producing B. belcheri embryos almost daily throughout the year. This advancement will provide essential embryonic material for evolutionary and developmental studies, and have great implications for the cultivation and spawning induction of other amphioxus species. PMID:24086537

  7. INFLUENCE OF SPAWNING GROUP SIZE AND SPACE ON REPRODUCTION BY SHEEPSHEAD MINNOWS, CYPRINODON VARIEGATUS

    EPA Science Inventory

    Cripe, G.M., R.L. Hemmer and L.R. Goodman. In press. Influence of Spawning Group Size and Space on Reproduction Variability of Sheepshead Minnows, Cyprinodon variegatus (Abstract). To be presented at the SETAC Fourth World Congress, 14-18 November 2004, Portland, OR. 1 p. (ERL,GB...

  8. MATERNAL TRANSFER OF BIOACTIVE POLYCHLORINATED AROMATIC HYDROCARBONS IN SPAWNING CHINOOK SALMON (ONCORHYNCHUS TSCHAWYTSCHA)

    EPA Science Inventory

    The biological potency (relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD) of planar polychlorinated aromatic hydrocarbons (PCHs) in extracts of eggs and flesh from spawning female chinook salmon (Oncorhynchus tschawytscha) from Lake Michigan was determined by measuring the i...

  9. Spatial and temporal characteristics of grouper spawning aggregations in marine protected areas in Palau, western Micronesia

    USGS Publications Warehouse

    Golbuu, Y.; Friedlander, A.M.

    2011-01-01

    In Palau, Ngerumekaol and Ebiil Channels are spawning aggregation sites that have been protected from fishing since 1976 and 2000, respectively. Groupers and other targeted fisheries species were monitored monthly over a 1.5 year period at these two spawning aggregations and two nearby exploited reference sites where grouper formerly aggregated to spawn. At the protected aggregation sites, three grouper species (Plectropomus areolatus, Epinephelus polyphekadion, and Epinephelus fuscoguttatus) accounted for 78% of the abundance and 85% of the biomass of all resource species surveyed but comprised <1% of the total abundance and biomass at reference sites not protected from fishing that formally harbored spawning aggregations. Abundance and biomass of grouper species pooled were 54% and 72% higher, respectively, at Ngerumekaol compared to Ebiil. Comparisons with data from the same locations in 1995-1996 showed order of magnitude declines in abundance of E. polyphekadion at both locations. The lower numbers of E. fuscoguttatus and the near absence of E. polyphekadion at Ebiil may reflect the effects of previous and current overexploitation. ?? 2011 Elsevier Ltd.

  10. Temperature affects the timing of spawning and migration of North Sea mackerel

    NASA Astrophysics Data System (ADS)

    Jansen, Teunis; Gislason, Henrik

    2011-01-01

    Climate change accentuates the need for knowing how temperature impacts the life history and productivity of economically and ecologically important species of fish. We examine the influence of temperature on the timing of the spawning and migrations of North Sea Mackerel using data from larvae CPR surveys, egg surveys and commercial landings from Danish coastal fisheries in the North Sea, Skagerrak, Kattegat and inner Danish waters. The three independent sources of data all show that there is a significant relationship between the timing of spawning and sea surface temperature. Large mackerel are shown to arrive at the feeding areas before and leave later than small mackerel and the sequential appearance of mackerel in each of the feeding areas studied supports the anecdotal evidence for an eastward post-spawning migration. Occasional commercial catches taken in winter in the Sound N, Kattegat and Skagerrak together with catches in the first quarter IBTS survey furthermore indicate some overwintering here. Significant relationships between temperature and North Sea mackerel spawning and migration have not been documented before. The results have implications for mackerel resource management and monitoring. An increase in temperature is likely to affect the timing and magnitude of the growth, recruitment and migration of North Sea mackerel with subsequent impacts on its sustainable exploitation.

  11. Olfactory navigation during spawning migrations: a review and introduction of the Hierarchical Navigation Hypothesis.

    PubMed

    Bett, Nolan N; Hinch, Scott G

    2016-08-01

    Migrations are characterized by periods of movement that typically rely on orientation towards directional cues. Anadromous fish undergo several different forms of oriented movement during their spawning migration and provide some of the most well-studied examples of migratory behaviour. During the freshwater phase of the migration, fish locate their spawning grounds via olfactory cues. In this review, we synthesize research that explores the role of olfaction during the spawning migration of anadromous fish, most of which focuses on two families: Salmonidae (salmonids) and Petromyzontidae (lampreys). We draw attention to limitations in this research, and highlight potential areas of investigation that will help fill in current knowledge gaps. We also use the information assembled from our review to formulate a new hypothesis for natal homing in salmonids. Our hypothesis posits that migrating adults rely on three types of cues in a hierarchical fashion: imprinted cues (primary), conspecific cues (secondary), and non-olfactory environmental cues (tertiary). We provide evidence from previous studies that support this hypothesis. We also discuss future directions of research that can test the hypothesis and further our understanding of the spawning migration. PMID:25923999

  12. Side-scan sonar mapping of lake trout spawning habitat in northern Lake Michigan

    USGS Publications Warehouse

    Edsall, Thomas A.; Poe, Thomas P.; Nester, Robert T.; Brown, Charles L.

    1989-01-01

    Native stocks of lake trout Salvelinus namaycush were virtually or completely extirpated from the lower four Great Lakes by the early 1960s. The failure of early attempts to reestablish self-sustaining populations of lake trout was attributed partly to the practice of stocking hatcheryreared juveniles at locations and over substrates that had not been used in the past for spawning by native fish. Subsequent attempts to improve the selection of stocking locations were impeded by the lack of reliable information on the distribution of substrates on historical spawning grounds. Here we demonstrate the potential of side-scan sonar to substantially expand the data base needed to pinpoint the location of substrates where lake trout eggs, fry, or juveniles could be stocked to maximize survival and help ensure that survivors returning to spawn would encounter suitable substrates. We also describe the substrates and bathymetry of large areas on historical lake trout spawning grounds in the Fox Island Lake Trout Sanctuary in northern Lake Michigan. These areas could be used to support a contemporary self-sustaining lake trout population in the sanctuary and perhaps also in adjacent waters.

  13. Floodplains within reservoirs promote earlier spawning of white crappies Pomoxis annularis

    USGS Publications Warehouse

    Miranda, Leandro E.; Dagel, Jonah D.; Kaczka, Levi J.; Mower, Ethan; Wigen, S. L.

    2015-01-01

    Reservoirs impounded over floodplain rivers are unique because they may include within their upper reaches extensive shallow water stored over preexistent floodplains. Because of their relatively flat topography and riverine origin, floodplains in the upper reaches of reservoirs provide broad expanses of vegetation within a narrow range of reservoir water levels. Elsewhere in the reservoir, topography creates a band of shallow water along the contour of the reservoir where vegetation often does not grow. Thus, as water levels rise, floodplains may be the first vegetated habitats inundated within the reservoir. We hypothesized that shallow water in reservoir floodplains would attract spawning white crappies Pomoxis annularis earlier than reservoir embayments. Crappie relative abundance over five years in floodplains and embayments of four reservoirs increased as spawning season approached, peaked, and decreased as fish exited shallow water. Relative abundance peaked earlier in floodplains than embayments, and the difference was magnified with higher water levels. Early access to suitable spawning habitat promotes earlier spawning and may increase population fitness. Recognition of the importance of reservoir floodplains, an understanding of how reservoir water levels can be managed to provide timely connectivity to floodplains, and conservation of reservoir floodplains may be focal points of environmental management in reservoirs.

  14. Toward responsible stock enhancement: broadcast spawning dynamics and adaptive genetic management in white seabass aquaculture

    PubMed Central

    Gruenthal, Kristen M; Drawbridge, Mark A

    2012-01-01

    The evolutionary effects captive-bred individuals that can have on wild conspecifics are necessary considerations for stock enhancement programs, but breeding protocols are often developed without the knowledge of realized reproductive behavior. To help fill that gap, parentage was assigned to offspring produced by a freely mating group of 50 white seabass (Atractoscion nobilis), a representative broadcast spawning marine finfish cultured for conservation. Similar to the well-known and closely related red drum (Sciaenops ocellatus), A. nobilis exhibited large variation in reproductive success. More males contributed and contributed more equally than females within and among spawns in a mating system best described as lottery polygyny. Two females produced 27% of the seasonal offspring pool and female breeding effective size averaged 1.85 per spawn and 12.38 seasonally, whereas male breeding effective size was higher (6.42 and 20.87, respectively), with every male contributing 1–7% of offspring. Further, females batch spawned every 1–5 weeks, while males displayed continuous reproductive readiness. Sex-specific mating strategies resulted in multiple successful mate pairings and a breeding effective to census size ratio of ≥0.62. Understanding a depleted species’ mating system allowed management to more effectively utilize parental genetic variability for culture, but the fitness consequences of long-term stocking can be difficult to address. PMID:25568060

  15. Identification of American shad spawning sites and habitat use in the Pee Dee River, North Carolina and South Carolina

    USGS Publications Warehouse

    Harris, Julianne E.; Hightower, Joseph E.

    2011-01-01

    We examined spawning site selection and habitat use by American shad Alosa sapidissima in the Pee Dee River, North Carolina and South Carolina, to inform future management in this flow-regulated river. American shad eggs were collected in plankton tows, and the origin (spawning site) of each egg was estimated; relocations of radio-tagged adults on spawning grounds illustrated habitat use and movement in relation to changes in water discharge rates. Most spawning was estimated to occur in the Piedmont physiographic region within a 25-river-kilometer (rkm) section just below the lowermost dam in the system; however, some spawning also occurred downstream in the Coastal Plain. The Piedmont region has a higher gradient and is predicted to have slightly higher current velocities and shallower depths, on average, than the Coastal Plain. The Piedmont region is dominated by large substrates (e.g., boulders and gravel), whereas the Coastal Plain is dominated by sand. Sampling at night (the primary spawning period) resulted in the collection of young eggs (≤1.5 h old) that more precisely identified the spawning sites. In the Piedmont region, most radio-tagged American shad remained in discrete areas (average linear range = 3.6 rkm) during the spawning season and generally occupied water velocities between 0.20 and 0.69 m/s, depths between 1.0 and 2.9 m, and substrates dominated by boulder or bedrock and gravel. Tagged adults made only small-scale movements with changes in water discharge rates. Our results demonstrate that the upstream extent of migration and an area of concentrated spawning occur just below the lowermost dam. If upstream areas have similar habitat, facilitating upstream access for American shad could increase the spawning habitat available and increase the population's size.

  16. A model of the effects of flow fluctuations on fall Chinook salmon spawning habitat availability in the Columbia River

    SciTech Connect

    Geist, David R.; Murray, Christopher J.; Hanrahan, Timothy P.; Xie, YuLong

    2008-12-01

    Previously we reported that about 30% to 60% of the area predicted to be used by fall Chinook salmon (Oncorhynchus tshawytscha) for spawning in the Hanford Reach of the Columbia River did not contain redds. One explanation for the overprediction of habitat was that our model did not incorporate streamflow fluctuation. Daily fluctuation in flow caused by load-following operations (power generation to meet short-term electrical demand) at Priest Rapids Dam, situated at the upper end of the Hanford Reach, changes the hydraulic characteristics to which fish respond in selecting redd sites. The purpose of the study described here was to examine the effect of flow changes on spawning habitat modeling and, in particular, to look at the connection between spawning and the variability and persistence of habitat variables caused by rapid changes in flow resulting from load-following operations at Priest Rapids Dam. We found that spawning habitat use by fall Chinook salmon was consistent with previous fall Chinook salmon studies in the Reach. Dynamic variables that were based on hourly time series were used to account for the variability in habitat as a result of flow fluctuations. The analysis showed that the proportion of velocities that fell within the range of 1.0 to 2.5 m/s differed significantly between locations that were predicted to be spawning by the logistic regression model where spawning actually occurred and locations that were predicted to be spawning where spawning did not occur. However, the resulting sequential logistic regression model that incorporated the dynamic variables did not provide significant improvement in the percentage of errors for areas predicted to be spawning; the model’s overprediction errors still ranged from 63% to 78%. We suggest that while flow fluctuation may affect spawning habitat and individual fish behavior, the high correlation between time-averaged velocities and the proportion of hourly velocities that fell within the most

  17. Individual Spawning Duration of Captive Atlantic Bluefin Tuna (Thunnus thynnus) Revealed by Mitochondrial DNA Analysis of Eggs

    PubMed Central

    Gordoa, Ana; Sanz, Nuria; Viñas, Jordi

    2015-01-01

    This study presents the first results on Atlantic bluefin tuna (Thunnus thynnus) individual spawning duration and its short-term temporal behavior. The study was based on direct measurements resulting from mtDNA analysis of the offspring of spawners held in transport cages during the 2013 spawning monitoring survey in Balearic waters. The number of females consisted of approximately 259 individuals with an average weight of 186 kg. The survey began on May 22 and ended on July 3. Spawning started on May 30 and was observed every night afterwards. The sampling of eggs for genetic monitoring was conducted for 9 days interspersed from the beginning of spawning to the end of the survey. A total of 946 eggs were analyzed and revealed 129 different haplotypes; 77 of these were not previously detected in the Mediterranean. A total of 69 haplotypes were observed in more than one spawning event and those with higher frequency lasted their maximum possible duration. The haplotypes present at the beginning of spawning were also identified at the end of the sampling, indicating a minimum spawning duration of 34 days, and individual annual fecundity was estimated at around 1290 eggs gr-1. These results differed from those generally presumed until now and are indicative of a much higher fecundity. Females exhibited a regular spawning schedule but with the capacity to shift the spawning hour during the spawning season. These results were observed for the eastern population of Atlantic bluefin tuna and before extrapolating to the western population, their validity should be proved. PMID:26317343

  18. A scientific basis for restoring fish spawning habitat in the St. Clair and Detroit Rivers of the Laurentian Great Lakes

    USGS Publications Warehouse

    Manny, Bruce A.; Roseman, Edward F.; Kennedy, Gregory W.; Boase, James C.; Craig, Jaquelyn; Bennion, David H.; Read, Jennifer; Vaccaro, Lynn; Chiotti, Justin A.; Drouin, Richard; Ellison, Roseanne

    2015-01-01

    Loss of functional habitat in riverine systems is a global fisheries issue. Few studies, however, describe the decision-making approach taken to abate loss of fish spawning habitat. Numerous habitat restoration efforts are underway and documentation of successful restoration techniques for spawning habitat of desirable fish species in large rivers connecting the Laurentian Great Lakes are reported here. In 2003, to compensate for the loss of fish spawning habitat in the St. Clair and Detroit Rivers that connect the Great Lakes Huron and Erie, an international partnership of state, federal, and academic scientists began restoring fish spawning habitat in both of these rivers. Using an adaptive management approach, we created 1,100 m2 of productive fish spawning habitat near Belle Isle in the Detroit River in 2004; 3,300 m2 of fish spawning habitat near Fighting Island in the Detroit River in 2008; and 4,000 m2 of fish spawning habitat in the Middle Channel of the St. Clair River in 2012. Here, we describe the adaptive-feedback management approach that we used to guide our decision making during all phases of spawning habitat restoration, including problem identification, team building, hypothesis development, strategy development, prioritization of physical and biological imperatives, project implementation, habitat construction, monitoring of fish use of the constructed spawning habitats, and communication of research results. Numerous scientific and economic lessons learned from 10 years of planning, building, and assessing fish use of these three fish spawning habitat restoration projects are summarized in this article.

  19. Reproductive Potential of Salmon Spawning Substrates Inferred from Grain Size and Fish Length

    NASA Astrophysics Data System (ADS)

    Riebe, C. S.; Sklar, L. S.; Overstreet, B. T.; Wooster, J. K.; Bellugi, D. G.

    2014-12-01

    The river restoration industry spends millions of dollars every year on improving salmon spawning in riverbeds where sediment is too big for fish to move and thus use during redd building. However, few studies have addressed the question of how big is too big in salmon spawning substrates. Hence managers have had little quantitative basis for gauging the amount of spawning habitat in coarse-bedded rivers. Moreover, the scientific framework has remained weak for restoration projects that seek to improve spawning conditions. To overcome these limitations, we developed a physically based, field-calibrated model for the fraction of the bed that is fine-grained enough to support spawning by fish of a given size. Model inputs are fish length and easy-to-measure indices of bed-surface grain size. Model outputs include the number of redds and eggs the substrate can accommodate when flow depth, temperature, and other environmental factors are not limiting. The mechanistic framework of the model captures the biophysical limits on sediment movement and the space limitations on redd building and egg deposition in riverbeds. We explored the parameter space of the model and found a previously unrecognized tradeoff in salmon size: bigger fish can move larger sediment and thus use more riverbed area for spawning; they also tend to have higher fecundity, and so can deposit more eggs per redd; however, because redd area increases with fish length, the number of eggs a substrate can accommodate is highest for moderate-sized fish. One implication of this tradeoff is that differences in grain size may help regulate river-to-river differences in salmon size. Thus, our model suggests that population diversity and, by extension, species resilience are linked to lithologic, geomorphic, and climatic factors that determine grain size in rivers. We cast the model into easy-to-use look-up tables, charts, and computer applications, including a JavaScript app that works on tablets and mobile

  20. Evaluation of Salmon Spawning below the Four Lowermost Columbia River Dams, 2004-2005 Annual Report.

    SciTech Connect

    Geist, David; Currie, Andrea

    2006-02-01

    Since FY 2000, scientists at Pacific Northwest National Laboratory (PNNL) have conducted research to assess the extent of spawning by chum (Oncorhynchus keta) and fall Chinook (O. tshawytscha) salmon in the lower mainstem Columbia River. Their work supports a larger Bonneville Power Administration (BPA) project aimed at characterizing the physical habitat used by mainstem fall Chinook and chum salmon populations. Multiple collaborators in addition to PNNL are involved in the BPA project--counterparts include the Washington Department of Fish and Wildlife (WDFW), U.S. Fish and Wildlife Service (USFWS), Pacific States Marine Fisheries Commission (PSMFC), U.S. Geological Survey (USGS), and Oregon Department of Fish and Wildlife (ODFW). Data resulting from the individual tasks each agency conducts are providing a sound scientific basis for developing strategies to operate the Federal Columbia River Power System (FCRPS) in ways that will effectively protect and enhance the chum and fall Chinook salmon populations--both listed as threatened under the Endangered Species Act. Fall Chinook salmon, thought to originate from Bonneville Hatchery, were first noted to be spawning downstream of Bonneville Dam by biologists from the WDFW in 1993. Known spawning areas include gravel beds on the Washington side of the river near Hamilton Creek and Ives Island. Limited spawning ground surveys were conducted in the area around Ives and Pierce islands during 1994 through 1997. Based on these surveys, fall Chinook salmon were believed to be spawning successfully in this area. In addition, chum salmon have been documented spawning downstream of Bonneville Dam. In FY 1999, BPA Project No. 1999-003 was initiated by the WDFW, ODFW, and the USFWS to characterize the variables associated with physical habitat used by mainstem fall Chinook and chum salmon populations and to better understand the effects of hydropower project operations on spawning and incubation. Pacific Northwest National

  1. A review of spawning induction, larviculture, and juvenile rearing of the fat snook, Centropomus parallelus.

    PubMed

    Cerqueira, V R; Tsuzuki, M Y

    2009-03-01

    The fat snook, Centropomus parallelus, is a commercially valuable marine fish species with potential for aquaculture. This paper describes the development of technology for mass production of fat snook juveniles at the Experimental Fish Hatchery of the Universidade Federal de Santa Catarina, focusing on research about reproduction, larviculture, and juvenile rearing. Induced spawning of wild fat snook was first achieved in 1991 with a single injection of human chorionic gonadotropin (hCG). There was a substantial increase in egg quality when broodstock was conditioned in maturation rooms and induced to spawn. Different dosages of luteinizing hormone-releasing hormone analogue (LHRHa) with saline injection and colesterol implant were also tested. As fat snook exhibits group-synchronous oocyte development, females could be induced to spawn (with 35-50 mug kg(-1) of LHRHa) once a month, resulting in up to four consecutive spawnings. Results of larval culture were highly variable at the beginning; survival rates were frequently around 1% until the juvenile stage. Several experiments were conducted to evaluate the effect of environmental factors and feeding quality on survival and growth. With the improvement of the spawning induction technique and better larviculture practices, survival rates increased to 10-30%. Studies on the particular requirements of juveniles in terms of stocking density, feeding, nutrition, and environmental factors were also performed in order to improve growth rates and feed utilization. The present study demonstrates the feasibility of mass production of fat snook juveniles. However, further research is needed to develop cost-effective grow-out technology. PMID:19189233

  2. First direct confirmation of grass carp spawning in a Great Lakes tributary

    USGS Publications Warehouse

    Embke, Holly S.; Kocovsky, Patrick M.; Richter, Catherine A.; Pritt, Jeremy J.; Christine M. Mayer; Qian, Song

    2016-01-01

    Grass carp (Ctenopharyngodon idella), an invasive species of Asian carp, has been stocked for many decades in the United States for vegetation control. Adult individuals have been found in all of the Great Lakes except Lake Superior, but no self-sustaining populations have yet been identified in Great Lakes tributaries. In 2012, a commercial fisherman caught four juvenile diploid grass carp in the Sandusky River, a major tributary to Lake Erie. Otolith microchemistry and the capture location of these fish permitted the conclusion that they were most likely produced in the Sandusky River. Due to this finding, we sampled ichthyoplankton using paired bongo net tows and larval light traps during June–August of 2014 and 2015 to determine if grass carp are spawning in the Sandusky River. From the samples collected in 2015, we identified and staged eight eggs that were morphologically consistent with grass carp. Five eggs were confirmed as grass carp using quantitative Polymerase Chain Reaction for a grass carp-specific marker, while the remaining three were retained for future analysis. Our finding confirms that grass carp are naturally spawning in this Great Lakes tributary. All eggs were collected during high-flow events, either on the day of peak flow or 1–2 days following peak flow, supporting an earlier suggestion that high flow conditions favor grass carp spawning. The next principal goal is to identify the spawning and hatch location(s) for the Sandusky River. Predicting locations and conditions where grass carp spawning is most probable may aid targeted management efforts.

  3. Seasonal Dynamics of Atlantic Herring (Clupea harengus L.) Populations Spawning in the Vicinity of Marginal Habitats

    PubMed Central

    Eggers, Florian; Slotte, Aril; Libungan, Lísa Anne; Johannessen, Arne; Kvamme, Cecilie; Moland, Even; Olsen, Esben M.; Nash, Richard D. M.

    2014-01-01

    Gillnet sampling and analyses of otolith shape, vertebral count and growth indicated the presence of three putative Atlantic herring (Clupea harengus L.) populations mixing together over the spawning season February–June inside and outside an inland brackish water lake (Landvikvannet) in southern Norway. Peak spawning of oceanic Norwegian spring spawners and coastal Skagerrak spring spawners occurred in March–April with small proportions of spawners entering the lake. In comparison, spawning of Landvik herring peaked in May–June with high proportions found inside the lake, which could be explained by local adaptations to the environmental conditions and seasonal changes of this marginal habitat. The 1.85 km2 lake was characterized by oxygen depletion occurring between 2.5 and 5 m depth between March and June. This was followed by changes in salinity from 1–7‰ in the 0–1 m surface layer to levels of 20–25‰ deeper than 10 m. In comparison, outside the 3 km long narrow channel connecting the lake with the neighboring fjord, no anoxic conditions were found. Here salinity in the surface layer increased over the season from 10 to 25‰, whereas deeper than 5 m it was stable at around 35‰. Temperature at 0–5 m depth increased significantly over the season in both habitats, from 7 to 14°C outside and 5 to 17°C inside the lake. Despite differences in peak spawning and utilization of the lake habitat between the three putative populations, there was an apparent temporal and spatial overlap in spawning stages suggesting potential interbreeding in accordance with the metapopulation concept. PMID:25372461

  4. Modeling spawning dates of Hucho taimen in Mongolia to establish fishery management zones.

    PubMed

    Vander Zanden, M Jake; Joppa, Lucas N; Allen, Brant C; Chandra, Sudeep; Gilroy, David; Hogan, Zeb; Maxted, Jeffrey T; Zhu, Jun

    2007-12-01

    The ecological impacts of recreational fisheries are of growing concern and pose a number of unique management challenges. Here we report on our efforts to provide guidance for managing a recreational fishery for taimen, the giant Eurasian trout (Hucho taimen) in Mongolia. This species has declined dramatically across its range of Siberia and Central Asia, and is currently listed as endangered in Mongolia. Strong populations persist in remote regions of Mongolia because of limited anthropogenic impacts and harvest, though interest in the fishery is expanding rapidly. Current fishing regulations list the spring "opening date" for taimen fishing as 15 June, although regulations have not been consistently enforced, partially because taimen spawn much earlier than 15 June in much of the country. Through a combination of statistical models, climate data, knowledge of taimen biology, and geographic information systems (GIS), we model taimen spawning dates for potential habitat in Mongolia. A parametric bootstrap procedure was used to simulate variability in spawning date derived from inter-annual climate variability and model error, from which we estimated the date in which taimen spawning is predicted to occur with 90% confidence. We recommend the designation of three fisheries management zones, with corresponding opening dates of 20 May, 1 June, and 15 June. Our fishery opening date recommendations are less restrictive than existing regulations. Provided there is little or no catch-and-release fishing mortality, this approach serves both environmental and human needs by protecting taimen during the reproductive period, while still allowing a post-spawning catch-and-release fishery that benefits local economies and generates revenue (through fishing concession fees) for local conservation efforts. PMID:18213968

  5. Lunar Phase Modulates Circadian Gene Expression Cycles in the Broadcast Spawning Coral Acropora millepora.

    PubMed

    Brady, Aisling K; Willis, Bette L; Harder, Lawrence D; Vize, Peter D

    2016-04-01

    Many broadcast spawning corals in multiple reef regions release their gametes with incredible temporal precision just once per year, using the lunar cycle to set the night of spawning. Moonlight, rather than tides or other lunar-regulated processes, is thought to be the proximate factor responsible for linking the night of spawning to the phase of the Moon. We compared patterns of gene expression among colonies of the broadcast spawning coral Acropora millepora at different phases of the lunar cycle, and when they were maintained under one of three experimentally simulated lunar lighting treatments: i) lunar lighting conditions matching those on the reef, or lunar patterns mimicking either ii) constant full Moon conditions, or iii) constant new Moon conditions. Normal lunar illumination was found to shift both the level and timing of clock gene transcription cycles between new and full moons, with the peak hour of expression for a number of genes occurring earlier in the evening under a new Moon when compared to a full Moon. When the normal lunar cycle is replaced with nighttime patterns equivalent to either a full Moon or a new Moon every evening, the normal monthlong changes in the level of expression are destroyed for most genes. In combination, these results indicate that daily changes in moonlight that occur over the lunar cycle are essential for maintaining normal lunar periodicity of clock gene transcription, and this may play a role in regulating spawn timing. These data also show that low levels of light pollution may have an impact on coral biological clocks. PMID:27132135

  6. Spawning of Bluefin Tuna in the Black Sea: Historical Evidence, Environmental Constraints and Population Plasticity

    PubMed Central

    MacKenzie, Brian R.; Mariani, Patrizio

    2012-01-01

    The lucrative and highly migratory Atlantic bluefin tuna, Thunnus thynnus (Linnaeus 1758; Scombridae), used to be distributed widely throughout the north Atlantic Ocean, Mediterranean Sea and Black Sea. Its migrations have supported sustainable fisheries and impacted local cultures since antiquity, but its biogeographic range has contracted since the 1950s. Most recently, the species disappeared from the Black Sea in the late 1980s and has not yet recovered. Reasons for the Black Sea disappearance, and the species-wide range contraction, are unclear. However bluefin tuna formerly foraged and possibly spawned in the Black Sea. Loss of a locally-reproducing population would represent a decline in population richness, and an increase in species vulnerability to perturbations such as exploitation and environmental change. Here we identify the main genetic and phenotypic adaptations that the population must have (had) in order to reproduce successfully in the specific hydrographic (estuarine) conditions of the Black Sea. By comparing hydrographic conditions in spawning areas of the three species of bluefin tunas, and applying a mechanistic model of egg buoyancy and sinking rate, we show that reproduction in the Black Sea must have required specific adaptations of egg buoyancy, fertilisation and development for reproductive success. Such adaptations by local populations of marine fish species spawning in estuarine areas are common as is evident from a meta-analysis of egg buoyancy data from 16 species of fish. We conclude that these adaptations would have been necessary for successful local reproduction by bluefin tuna in the Black Sea, and that a locally-adapted reproducing population may have disappeared. Recovery of bluefin tuna in the Black Sea, either for spawning or foraging, will occur fastest if any remaining locally adapted individuals are allowed to survive, and by conservation and recovery of depleted Mediterranean populations which could through time re

  7. Efficiency of treatments for controlling Trichoderma spp during spawning in cultivation of lignicolous mushrooms

    PubMed Central

    Colavolpe, María Belén; Mejía, Santiago Jaramillo; Albertó, Edgardo

    2014-01-01

    Trichoderma spp is the cause of the green mold disease in mushroom cultivation production. Many disinfection treatments are commonly applied to lignocellulose substrates to prevent contamination. Mushroom growers are usually worried about the contaminations that may occur after these treatments during handling or spawning. The aim of this paper is to estimate the growth of the green mold Trichoderma sp on lignocellulose substrates after different disinfection treatments to know which of them is more effective to avoid contamination during spawning phase. Three different treatments were assayed: sterilization (121 °C), immersion in hot water (60 and 80 °C), and immersion in alkalinized water. Wheat straw, wheat seeds and Eucalyptus or Populus sawdust were used separately as substrates. After the disinfection treatments, bagged substrates were sprayed with 3 mL of suspension of conidia of Trichoderma sp (105 conidia/mL) and then separately spawned with Pleurotus ostreatus or Gymnopilus pampeanus. The growth of Trichoderma sp was evaluated based on a qualitative scale. Trichoderma sp could not grow on non-sterilized substrates. Immersions in hot water treatments and immersion in alkalinized water were also unfavorable treatments for its growth. Co- cultivation with mushrooms favored Trichoderma sp growth. Mushroom cultivation disinfection treatments of lignocellulose substrates influence on the growth of Trichoderma sp when contaminations occur during spawning phase. The immersion in hot water at 60 °C for 30 min or in alkalinized water for 36 h, are treatments which better reduced the contaminations with Trichoderma sp during spawning phase for the cultivation of lignicolous species. PMID:25763030

  8. Dynamic height: A key variable for identifying the spawning habitat of small pelagic fishes

    NASA Astrophysics Data System (ADS)

    Asch, Rebecca G.; Checkley, David M., Jr.

    2013-01-01

    Small pelagic fishes off southern California exhibit interannual variations in the regions they occupy. An enhanced understanding of these fluctuations could improve fisheries management and predictions of fish's responses to climate change. We investigated dynamic height as a variable for identifying the spawning habitat of northern anchovy (Engraulis mordax), Pacific sardine (Sardinops sagax), and jack mackerel (Trachurus symmetricus). During cruises between 1998 and 2004, dynamic height was calculated from temperature and salinity profiles, while fish egg concentration was measured with obliquely towed bongo nets and the Continuous, Underway Fish Egg Sampler. Dynamic height ranged between 68 and 108 cm, with values increasing offshore. The greatest probability of encountering anchovy, sardine, and jack mackerel eggs occurred at dynamic heights of 79-83 cm, 84-89 cm, and 89-99 cm, respectively. Four mechanisms were proposed to explain how dynamic height affects egg distribution: (1) dynamic height is a proxy for upper water column temperature and salinity, which are known to influence spawning habitat. (2) Low dynamic heights are indicative of coastal upwelling, which increases primary and secondary productivity. (3) Egg concentration is greater at dynamic heights coincident with geostrophic currents that transport larvae to favorable habitats. (4) Eddies delineated by dynamic height contours retain eggs in productive habitats. To evaluate these mechanisms, a generalized linear model was constructed using dynamic height, temperature, salinity, chlorophyll, zooplankton volume, geostrophic currents, and eddies as independent variables. Dynamic height explained more variance than any other variable in models of sardine and anchovy spawning habitat. Together temperature, salinity, and chlorophyll accounted for 80-95% of the dynamic height effect, emphasizing the importance of the first two mechanisms. However, dynamic height remained statistically significant in the

  9. Effect of horseshoe crab spawning density on nest disturbance and exhumation of eggs: A simulation study

    USGS Publications Warehouse

    Smith, D.R.

    2007-01-01

    Because the Delaware Bay horseshoe crab (Limulus polyphemus) population is managed to provide for dependent species, such as migratory shorebirds, there is a need to understand the process of egg exhumation and to predict eggs available to foraging shorebirds. A simple spatial model was used to simulate horseshoe crab spawning that would occur on a typical Delaware Bay beach during spring tide cycles to quantify density-dependent nest disturbance. At least 20% of nests and eggs were disturbed for levels of spawning greater than one third of the average density in Delaware Bay during 2004. Nest disturbance increased approximately linearly as spawning density increased from one half to twice the 2004 level. As spawning density increased further, the percentage of eggs that were disturbed reached an asymptote of 70% for densities up to 10 times the density in 2004. Nest disturbance was heaviest in the mid beach zone. Nest disturbance precedes entrainment and begins the process of exhumation of eggs to surface sediments. Model predictions were combined with observations from egg surveys to estimate a snap-shot exhumation rate of 5-9% of disturbed eggs. Because an unknown quantity of eggs were exhumed and removed from the beach prior to the survey, cumulative exhumation rate was likely to have been higher than the snap-shot estimate. Because egg exhumation is density-dependent, in addition to managing for a high population size, identification and conservation of beaches where spawning horseshoe crabs concentrate in high densities (i.e., hot spots) are important steps toward providing a reliable food supply for migratory shorebirds. ?? 2007 Estuarine Research Federation.

  10. Redd Site Selection and Spawning Habitat Use by Fall Chinook Salmon, Hanford Reach, Columbia River : Final Report 1995 - 1998.

    SciTech Connect

    Geist, David R.

    1999-05-01

    This report summarizes results of research activities conducted from 1995 through 1998 on identifying the spawning habitat requirements of fall chinook salmon (Oncorhynchus tshawytscha) in the Hanford Reach of the Columbia River. The project investigated whether traditional spawning habitat models could be improved in order to make better predictions of available habitat for fall chinook salmon in the Snake River. Results suggest models could be improved if they used spawning area-specific, rather than river-specific, spawning characteristics; incorporated hyporheic discharge measurements; and gave further consideration to the geomorphic features that are present in the unconstrained segments of large alluvial rivers. Ultimately the recovery of endangered fall chinook salmon will depend on how well we are able to recreate the characteristics once common in alluvial floodplains of large rivers. The results from this research can be used to better define the relationship between these physical habitat characteristics and fall chinook salmon spawning site selection, and provide more efficient use of limited recovery resources. This report is divided into four chapters which were presented in the author's doctoral dissertation which he completed through the Department of Fisheries and Wildlife at Oregon State University. Each of the chapters has been published in peer reviewed journals or is currently under review. Chapter one is a conceptual spawning habitat model that describes how geomorphic features of river channels create hydraulic processes, including hyporheic flows, that influence where salmon spawn in unconstrained reaches of large mainstem alluvial rivers. Chapter two describes the comparison of the physical factors associated with fall chinook salmon redd clusters located at two sites within the Reach. Spatial point pattern analysis of redds showed that redd clusters averaged approximately 10 hectares in area and their locations were consistent from year to

  11. How Well Can We Predict Salmonid Spawning Habitat with LiDAR?

    NASA Astrophysics Data System (ADS)

    Pfeiffer, A.; Finnegan, N. J.; Hayes, S.

    2013-12-01

    Suitable salmonid spawning habitat is, to a great extent, determined by physical, landscape driven characteristics such as channel morphology and grain size. Identifying reaches with high-quality spawning habitat is essential to restoration efforts in areas where salmonid species are endangered or threatened. While both predictions of suitable habitat and observations of utilized habitat are common in the literature, they are rarely combined. Here we exploit a unique combination of high-resolution LiDAR data and seven years of 387 individually surveyed Coho and Steelhead redds in Scott Creek, a 77 km2 un-glaciated coastal California drainage in the Santa Cruz Mountains, to both make and test predictions of spawning habitat. Using a threshold channel assumption, we predict grain size throughout Scott Creek via a shear stress model that incorporates channel width, instead of height, using Manning's equation (Snyder et al., 2013). Slope and drainage area are computed from a LiDAR-derived DEM, and channel width is calculated via hydraulic modeling. Our results for median grain size predictions closely match median grain sizes (D50) measured in the field, with the majority of sites having predicted D50's within a factor of two of the observed values, especially for reaches with D50 > 0.02m. This success suggests that the threshold model used to predict grain size is appropriate for un-glaciated alluvial channel systems. However, it appears that grain size alone is not a strong predictor of salmon spawning. Reaches with a high (>0.1m) average predicted D50 do have lower redd densities, as expected based on spawning gravel sizes in the literature. However, reaches with lower (<0.1m) predicted D50 have a wide range of redd densities, suggesting that reach-average grain size alone cannot explain spawning site selection in the finer-grained reaches of Scott Creek. We turn to analysis of bedform morphology in order to explain the variation in redd density in the low

  12. Beach characteristics mitigate effects of onshore wind on horseshoe crab spawning: Implications for matching with shorebird migration in Delaware Bay

    USGS Publications Warehouse

    Smith, D.R.; Jackson, N.L.; Nordstrom, K.F.; Weber, R.G.

    2011-01-01

    Disruption of food availability by unfavorable physical processes at energetically demanding times can limit recruitment of migratory species as predicted by the match-mismatch hypothesis. Identification and protection of disruption-resistant habitat could contribute to system resilience. For example, horseshoe crab Limulus polyphemus spawning and shorebird stopover must match temporally in Delaware Bay for eggs to be available to shorebirds. Onshore winds that generate waves can create a mismatch by delaying horseshoe crab spawning. We examined effects of beach characteristics and onshore winds on spawning activity at five beaches when water temperatures were otherwise consistent with early spawning activity. Onshore winds resulted in reduced spawning activity during the shorebird stopover, when spawning typically peaks in late May. During the period with high onshore wind, egg density was highest on the foreshore exposed to the lowest wave heights. Onshore wind was low in early June, and spawning and egg densities were high at all sites, but shorebirds had departed. Beaches that can serve as a refuge from wind and waves can be identified by physical characteristics and orientation to prevailing winds and should receive special conservation status, especially in light of predicted increases in climate change-induced storm frequency. These results point to a potential conservation strategy that includes coastal management for adapting to climate change-induced mismatch of migrations. ?? 2011 The Authors. Animal Conservation ?? 2011 The Zoological Society of London.

  13. Identification of a female spawn-associated Kazal-type inhibitor from the tropical abalone Haliotis asinina.

    PubMed

    Wang, Tianfang; Nuurai, Parinyaporn; McDougall, Carmel; York, Patrick S; Bose, Utpal; Degnan, Bernard M; Cummins, Scott F

    2016-07-01

    Abalone (Haliotis) undergoes a period of reproductive maturation, followed by the synchronous release of gametes, called broadcast spawning. Field and laboratory studies have shown that the tropical species Haliotis asinina undergoes a two-week spawning cycle, thus providing an excellent opportunity to investigate the presence of endogenous spawning-associated peptides. In female H. asinina, we have isolated a peptide (5145 Da) whose relative abundance in hemolymph increases substantially just prior to spawning and is still detected using reverse-phase high-performance liquid chromatography chromatograms up to 1-day post-spawn. We have isolated this peptide from female hemolymph as well as samples prepared from the gravid female gonad, and demonstrated through comparative sequence analysis that it contains features characteristic of Kazal-type proteinase inhibitors (KPIs). Has-KPI is expressed specifically within the gonad of adult females. A recombinant Has-KPI was generated using a yeast expression system. The recombinant Has-KPI does not induce premature spawning of female H. asinina when administered intramuscularly. However it displays homomeric aggregations and interaction with at least one mollusc-type neuropeptide (LRDFVamide), suggesting a role for it in regulating neuropeptide endocrine communication. This research provides new understanding of a peptide that can regulate reproductive processes in female abalone, which has the potential to lead to the development of greater control over abalone spawning. The findings also highlight the need to further explore abalone reproduction to clearly define a role for novel spawning-associated peptide in sexual maturation and spawning. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27352998

  14. Flow and sediment-transport modeling of Kootenai River White Sturgeon Spawning Habitat.

    NASA Astrophysics Data System (ADS)

    McDonald, R. R.; Nelson, J.; Barton, G.; Paragamian, V.

    2004-12-01

    The population of White Sturgeon in the Kootenai River downstream of Libby Dam in Montana and Idaho has declined since the construction of the dam in 1972. The White Sturgeon was listed as endangered in 1994 and an 11.2 mile reach of the river, downstream of Bonners Ferry, Idaho was designated as Critical Habitat in 2001. It is hypothesized that hydro-electric and flood control operations have contributed to poor spawning habitat and recruitment of juvenile fish. The successful incubation of eggs requires a stable and coarse bed material. Currently the sturgeon are spawning in a reach of poor substrate consisting of dunes up to 2 meters in amplitude and composed of fine sand while a short distance upstream there is suitable substrate of coarse gravel. We present here the preliminary results of a flow and sediment-transport modeling effort to aid in an understanding of both the current spawning habitat of the White Sturgeon and the potential to artificially enhance the current spawning habitat or to influence the sturgeon to move upstream to more suitable habitat. A 2.5 dimensional flow model was constructed for an 8-kilometer reach of the designated Critical Habitat. The modeled reach consists of several broad meanders and a mid channel island. The substrate is composed of fine sand with a median grain size of 0.22mm and has large dunes up to 2m in amplitude at relatively lows flows of 200 cms that wash out to a plane bed at around 600 cms. The model has been calibrated to a range of historical flow conditions from 170 cms to 1709 cms and verified against 16 ADCP velocity cross-section profiles collected during a period of steady flow at 554 cms. The model predicts well most of the salient features of the velocity field including the magnitude and location of the secondary flow, using a simple constant value for roughness. However for a few reaches of the river the bed forms and their spatial variability in size are shown to significantly affect the flow and the

  15. Characteristics of fall chum salmon spawning habitat on a mainstem river in Interior Alaska

    USGS Publications Warehouse

    Burril, Sean E.; Zimmerman, Christian E.; Finn, James E.

    2010-01-01

    Chum salmon (Oncorhynchus keta) are the most abundant species of salmon spawning in the Yukon River drainage system, and they support important personal use, subsistence, and commercial fisheries. Chum salmon returning to the Tanana River in Interior Alaska are a significant contribution to the overall abundance of Yukon River chum salmon and an improved understanding of habitat use is needed to improve conservation of this important resource. We characterized spawning habitat of chum salmon using the mainstem Tanana River as part of a larger study to document spawning distributions and habitat use in this river. Areas of spawning activity were located using radiotelemetry and aerial helicopter surveys. At 11 spawning sites in the mainstem Tanana River, we recorded inter-gravel and surface-water temperatures and vertical hydraulic gradient (an indication of the direction of water flux) in substrate adjacent to salmon redds. At all locations, vertical hydraulic gradient adjacent to redds was positive, indicating that water was upwelling through the gravel. Inter-gravel temperatures adjacent to redds generally were warmer than surface water at most locations and were more stable than surface-water temperature. Inter-gravel water temperature adjacent to redds ranged from 2.6 to 5.8 degrees Celsius, whereas surface-water temperature ranged from greater than 0 to 5.5 degrees Celsius. Some sites were affected more by extremes in air temperature than others. At these sites, inter-gravel water temperature profiles were variable (with ranges similar to those observed in surface water), suggesting that even though upwelling habitats provide a stable thermal incubation environment, eggs and embryos still may be affected by extremes in air temperature. Fine sand and silt covered redds at multiple sites and were evidence of increased river flow during the winter months, which may be a potential source of increased mortality during egg-to-fry development. This study provides

  16. Visual observations of historical lake trout spawning grounds in western Lake Huron

    USGS Publications Warehouse

    Nester, Robert T.; Poe, Thomas P.

    1987-01-01

    Direct underwater video observations were made of the bottom substrates at 12 spawning grounds formerly used by lake trout Salvelinus namaycush in western Lake Huron to evaluate their present suitability for successful reproduction by lake trout. Nine locations examined north of Saginaw Bay in the northwestern end of the lake are thought to provide the best spawning habitat. The substrate at these sites consisted of angular rough cobble and rubble with relatively deep interstitial spaces (a?Y 0.5 m), small amounts of fine sediments, and little or no periphytic growth. Conditions at the three other sampling locations south of Saginaw Bay seemed much less suitable for successful reproduction based on the reduced area of high-quality substrate, shallow interstitial spaces, high infiltration of fine sediments, and greater periphytic growth.

  17. Communication: GAIMS—generalized ab initio multiple spawning for both internal conversion and intersystem crossing processes

    DOE PAGESBeta

    Curchod, Basile F. E.; Rauer, Clemens; Marquetand, Philipp; Gonzalez, Leticia; Martinez, Todd J.

    2016-03-11

    Full Multiple Spawning is a formally exact method to describe the excited-state dynamics of molecular systems beyond the Born-Oppenheimer approximation. However, it has been limited until now to the description of radiationless transitions taking place between electronic states with the same spin multiplicity. This Communication presents a generalization of the full and ab initio Multiple Spawning methods to both internal conversion (mediated by nonadiabatic coupling terms) and intersystem crossing events (triggered by spin-orbit coupling matrix elements) based on a spin-diabatic representation. Lastly, the results of two numerical applications, a model system and the deactivation of thioformaldehyde, validate the presented formalismmore » and its implementation.« less

  18. The gill maggot Salmincola salmoneus as an indicator of repeat spawning in Atlantic salmon Salmo salar.

    PubMed

    Kusterle, S; Halttunen, E; Thorstad, E B; Naesje, T F; Jensen, J L A; Gallo-Bueno, A; Olague, E; Rikardsen, A H

    2013-03-01

    The potential of the gill maggot Salmincola salmoneus for use as an indicator of repeat spawning in Atlantic salmon Salmo salar was studied in adult fish captured during their return migration to the River Alta (n = 659) and River Namsen (n = 540) in Norway. Eighty-eight and 49% of previous spawners identified by scale readings were infected with S. salmoneus in the two rivers, respectively. Salmincola salmoneus can be used as a reliable, rapid and objective field indicator of repeat spawning in S. salar as nearly all infected fish (99·4%) were identified as repeat spawners, although it is important to have appropriate background information on S. salmoneus prevalence on the postspawning individuals within the same population. PMID:23464562

  19. Sex-specific daily spawning seaward migration of striped mullet Mugil cephalus in a coastal lagoon.

    PubMed

    Katselis, G; Koukou, K; Ramfos, A; Moutopoulos, D K

    2015-08-01

    The sex-specific daily spawning seaward migration of striped mullet Mugil cephalus was analysed in Palaiopotamos Lagoon (western Greek coast, eastern Mediterranean Sea) in an 86 day time series. The data set included the daily number of M. cephalus catches in barrier traps, as well as a time series of some weather variables. The analysis revealed an important linkage of the daily migration rate as well as a sex-specific response of the species to the lunar cycle and the short-term fluctuation of weather variables. The daily migration pattern of females was more persistent than that of males, indicating a possible female leadership role during the spawning migration. Multiregression models described quite accurately the sex-specific daily migration rates of the species, thus providing a potentially powerful tool regarding the lagoon fishery management of M. cephalus, especially in the context of climate change. PMID:26108151

  20. Gonadal Development, Spawning and Plasma Sex Steroid Levels of the Indoor Cultured Grunt, Hapalogenys nitens

    PubMed Central

    Kang, Hee Woong; Cho, Jae-Kwon; Son, Maeng-Hyun; Park, Jong Youn; Hong, Chang Gi; Chung, Jae Seung; Chung, Ee-Yung

    2015-01-01

    The gonadosomatic index (GSI), gonadal development and changes in hormones in plasma level of the indoor cultured grunt (Hapalogenys nitens) were investigated by histological study from August 2011 to October 2012. The GSI showed similar trends with gonad developmental stages during the culture periods. Changes in plasma level of estradiol-17β of female H. nitens reached the highest value before the spawning period, and seasonal changes in plasma level of estradiol-17β were similar in trends of oocyte developments and GSI changes. Testosterone levels of male H. nitens reached the highest value before and after the spent stage. Ovarian developmental stages of H. nitens could be classified into early growing stage, late growing stage, mature stage, ripe and spawning stage, recovery and resting stage. The testicular developmental stages could be divided into growing stage, mature stage, ripe and spent stage, and recovery and resting stage. PMID:25949208

  1. Sediment transport and siltation of brown trout (Salmo trutta L.) spawning gravels in chalk streams

    NASA Astrophysics Data System (ADS)

    Acornley, R. M.; Sear, D. A.

    1999-02-01

    Deposition rates of fine sediment into brown trout spawning gravels were measured at monthly intervals for a period of one year in a small channel of the River Test, Hampshire. Data were also collected on stream discharge, water depth, flow velocity and suspended sediment concentrations. Deposition rates followed a seasonal pattern and were maximal during periods of high discharge in the late winter/early spring when suspended sediment concentrations were high. The material deposited in the spawning gravels included silts and fine sands (<250 m) that were transported in suspension and coarser fragments of low density tufa-like material that were transported as bed load. The ecological implications of fine sediment deposition for salmonid egg survival in chalk streams are considered.

  2. Water temperatures within spawning beds in two chalk streams and implications for salmonid egg development

    NASA Astrophysics Data System (ADS)

    Acornley, R. M.

    1999-02-01

    Water temperatures within brown trout (Salmo trutta L.) spawning gravels were measured in two Hampshire chalk streams from October 1995 to April 1996 inclusive. During the winter, mean intra-gravel water temperatures were higher than those in the stream, and increased with depth in the gravel bed. The amplitude of diel fluctuations in water temperature decreased with depth in the gravel bed, although diel fluctuations were still evident at a depth of 30 cm. Differences in intra-gravel temperature gradients between the two study sites were attributed to differences in the amplitude of stream water temperature fluctuations and there was no evidence that either of the study sites were located in zones of upwelling groundwater. Published equations are used to predict, from temperature, the timing of important stages in the development of brown trout embryos (eyeing, hatching and emergence) for eggs spawned in the autumn and winter and buried at different depths in the gravel bed.

  3. Hot moments in spawning aggregations: implications for ecosystem-scale nutrient cycling

    NASA Astrophysics Data System (ADS)

    Archer, Stephanie K.; Allgeier, Jacob E.; Semmens, Brice X.; Heppell, Scott A.; Pattengill-Semmens, Christy V.; Rosemond, Amy D.; Bush, Phillippe G.; McCoy, Croy M.; Johnson, Bradley C.; Layman, Craig A.

    2015-03-01

    Biogeochemical hot moments occur when a temporary increase in availability of one or more limiting reactants results in elevated rates of biogeochemical reactions. Many marine fish form transient spawning aggregations, temporarily increasing their local abundance and thus nutrients supplied via excretion at the aggregation site. In this way, nutrients released by aggregating fish could create a biogeochemical hot moment. Using a combination of empirical and modeling approaches, we estimate nitrogen and phosphorus supplied by aggregating Nassau grouper ( Epinephelus striatus). Data suggest aggregating grouper supply up to an order-of-magnitude more nitrogen and phosphorus than daily consumer-derived nutrient supply on coral reefs without aggregating fish. Comparing current and historic aggregation-level excretion estimates shows that overfishing reduced nutrients supplied by aggregating fish by up to 87 %. Our study illustrates a previously unrecognized ecosystem viewpoint regarding fish spawning aggregations and provides an additional perspective on the repercussions of their overexploitation.

  4. Monitoring Spawning Activity in a Southern California Marine Protected Area Using Molecular Identification of Fish Eggs

    PubMed Central

    Harada, Alice E.; Lindgren, Elise A.; Hermsmeier, Maiko C.; Rogowski, Peter A.; Terrill, Eric; Burton, Ronald S.

    2015-01-01

    In order to protect the diverse ecosystems of coastal California, a series of marine protected areas (MPAs) have been established. The ability of these MPAs to preserve and potentially enhance marine resources can only be assessed if these habitats are monitored through time. This study establishes a baseline for monitoring the spawning activity of fish in the MPAs adjacent to Scripps Institution of Oceanography (La Jolla, CA, USA) by sampling fish eggs from the plankton. Using vertical plankton net tows, 266 collections were made from the Scripps Pier between 23 August 2012 and 28 August 2014; a total of 21,269 eggs were obtained. Eggs were identified using DNA barcoding: the COI or 16S rRNA gene was amplified from individual eggs and sequenced. All eggs that were successfully sequenced could be identified from a database of molecular barcodes of California fish species, resulting in species-level identification of 13,249 eggs. Additionally, a surface transport model of coastal circulation driven by current maps from high frequency radar was used to construct probability maps that estimate spawning locations that gave rise to the collected eggs. These maps indicated that currents usually come from the north but water parcels tend to be retained within the MPA; eggs sampled at the Scripps Pier have a high probability of having been spawned within the MPA. The surface transport model also suggests that although larvae have a high probability of being retained within the MPA, there is also significant spillover into nearby areas outside the MPA. This study provides an important baseline for addressing the extent to which spawning patterns of coastal California species may be affected by future changes in the ocean environment. PMID:26308928

  5. Horseshoe crab, Tachypleus gigas (Müller, 1785) spawning population at Balok Beach, Kuantan, Pahang, Malaysia.

    PubMed

    Tan, A N; Christianus, A; Shakibazadeh, S; Hajeb, P

    2012-07-01

    Local and regional decline of Asian horseshoe crabs has spurred a study on its spawning population at Balok Beach, Kuantan, Pahang, Malaysia. This location was identified as spawning site due to the occurrence of horseshoe crab spawning pairs and nests. Size-frequency, length-weight relationships, sex ratio and epibiont infestation of Tachypleus gigas were studied. Instar stage was estimated based on prosomal width. Condition of the horseshoe crab carapace was reported. Visual search technique of horseshoe crab was conducted during high tide of new and full moons. Prosomal, opisthosomal and telson length and weight of each horseshoe crab were measured. Largest female was recorded with mean prosomal length and width of 154.4 and 246.9 mm, respectively. About 69.8% of the males belonged to size group of 151-200 mm and 53.3% of females were grouped into 201-250 mm. All individuals were of fourteenth to sixteenth instar stages. Sex ratio varied from 0.313 to 2.5 and attributed to commercial harvest and monsoon season. Sand sediment of study site showed 93% of fine sands with grain size ranged from 120 to 250 microm. Acorn and pedunculate barnacle, conical and flat slipper shells were found on the carapace of the specimens. Most males had damaged eyes and carapaces while females with broken telsons. Body damages of about 19.9% on the specimens were likely due to nearby fishing activities. Lack of satellite male indicated low spawning population. The finding of this study showed that the species is extremely threatened by human activities and coastal development. PMID:24218930

  6. Spawning success in the damselfish Amblyglyphidodon leucogaster: the influence of eggs in the nest

    PubMed

    Goulet

    1998-03-01

    Spawning success of males and its correlates were investigated in a natural colony of whitebelly damselfish, A. leucogaster (Pomacentridae), to explore the criteria that females use in choosing mates. The mating success of individual males was variable, with some males acquiring as few as 5000 eggs and others as many as 450 000 eggs during a breeding season. Male spawning success was not correlated with body size, territory size, nest site parameters or parental care behaviour. Egg hatching success was not related to either male size or egg clutch size, and all males were capable of rearing eggs to hatching. The temporal sequence of choices by females indicated non-independent choice by females, such that males chosen by females on the first spawn of the day were also chosen by females that spawned later in the day. Field observations indicated that, in the absence of male courtship, females preferentially visited males that had eggs in their nest site. Males that had recently mated were preferred by females over those males with either late-stage eggs or no eggs in the nest. This female preference did not appear to be related to increased paternal care or egg clutch survival. Given that the mating system is promiscuous and non-resource based, and that there appears to be little difference among males in body size, females may be mating non-independently by mimicking the choice of other females. Copyright 1998 The Association for the Study of Animal Behaviour Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9514684

  7. Feeding activity and spawning time of striped bass in the Colorado River Inlet, Lake Powell, Utah

    USGS Publications Warehouse

    Persons, William R.; Bulkly, R.V.

    1982-01-01

    Striped bass, Morone saxatilis, from Lake Powell, Utah spawned in or near the mixing zone of the reservoir and the Colorado River in 1980 and 1981. The fish did not move through Cataract Canyon rapids just above the reservoir in either year. Of 321 adult striped bass stomachs examined, 30% contained food and 28% contained threadfin shad, Dorosoma petenense. No stomachs contained native threatened or endangered Colorado River fishes.

  8. Monitoring Spawning Activity in a Southern California Marine Protected Area Using Molecular Identification of Fish Eggs.

    PubMed

    Harada, Alice E; Lindgren, Elise A; Hermsmeier, Maiko C; Rogowski, Peter A; Terrill, Eric; Burton, Ronald S

    2015-01-01

    In order to protect the diverse ecosystems of coastal California, a series of marine protected areas (MPAs) have been established. The ability of these MPAs to preserve and potentially enhance marine resources can only be assessed if these habitats are monitored through time. This study establishes a baseline for monitoring the spawning activity of fish in the MPAs adjacent to Scripps Institution of Oceanography (La Jolla, CA, USA) by sampling fish eggs from the plankton. Using vertical plankton net tows, 266 collections were made from the Scripps Pier between 23 August 2012 and 28 August 2014; a total of 21,269 eggs were obtained. Eggs were identified using DNA barcoding: the COI or 16S rRNA gene was amplified from individual eggs and sequenced. All eggs that were successfully sequenced could be identified from a database of molecular barcodes of California fish species, resulting in species-level identification of 13,249 eggs. Additionally, a surface transport model of coastal circulation driven by current maps from high frequency radar was used to construct probability maps that estimate spawning locations that gave rise to the collected eggs. These maps indicated that currents usually come from the north but water parcels tend to be retained within the MPA; eggs sampled at the Scripps Pier have a high probability of having been spawned within the MPA. The surface transport model also suggests that although larvae have a high probability of being retained within the MPA, there is also significant spillover into nearby areas outside the MPA. This study provides an important baseline for addressing the extent to which spawning patterns of coastal California species may be affected by future changes in the ocean environment. PMID:26308928

  9. Biogeomorphic impacts of migration and disturbance: Implications of salmon spawning and decay

    NASA Astrophysics Data System (ADS)

    Albers, S. J.; Petticrew, E. L.

    2013-11-01

    Geomorphologic processes often involve a biotic element that acts to regulate landform development. This biotic element can be plant or animal-based with a feedback that ultimately benefits the ecology of the organism. Pacific salmon (Oncorhynchus sp.) are an example of an animal biogeomorphic agent exhibiting such feedbacks and, because of long migrations from the sea to freshwater spawning grounds, are a species of interest that act on both local and regional scales. Upon returning to their natal streams, salmon generate a dual disturbance, resuspending large amounts of sediment as they construct nests while at the same time generating a substantial nutrient pulse through post-spawn die-off and decay. The retention and export of these nutrients are of importance to any hypothesized productivity boost driven by the marine derived nutrients (MDNs). Using experimental enclosures in the Horsefly River spawning channel in north-central British Columbia, our objectives for this study were to i) quantify the magnitude of organic and inorganic sediment export and retention from an active-spawning area and ii) determine the contribution of fine sediment MDN storage. Using a suspended sediment mass balance model, marine isotope enrichment and a time series of gravel bed sediment infiltration, we found strongly linear relationships between sediment infiltration and marine-derived nutrient enrichment. Elevated suspended sediment produced by salmon redd (nest) construction acted as an effective vector for MDN infiltration into the gravel bed. This study demonstrated that localized patterns of sediment deposition are regulated by salmon activity which in turn act to control MDN storage within, and release from, the gravel bed. Furthermore, this study demonstrates the ability of a biogeomorphic agent like salmon to establish a feedback mechanism that creates favorable conditions which ultimately benefit the organism.

  10. Evaluation of Fall Chinook and Chum Salmon Spawning below Bonneville Dam; 2004-2005 Annual Report.

    SciTech Connect

    van der Naald, Wayne; Duff, Cameron; Friesen, Thomas A.

    2006-02-01

    Pacific salmon Oncorhynchus spp. populations have declined over the last century due to a variety of human impacts. Chum salmon O. keta populations in the Columbia River have remained severely depressed for the past several decades, while upriver bright (URB) fall Chinook salmon O. tschawytscha populations have maintained relatively healthy levels. For the past seven years we have collected data on adult spawning and juvenile emergence and outmigration of URB fall Chinook and chum salmon populations in the Ives and Pierce islands complex below Bonneville Dam. In 2004, we estimated 1,733 fall Chinook salmon and 336 chum salmon spawned in our study area. Fall Chinook salmon spawning peaked 19 November with 337 redds and chum salmon spawning peaked 3 December with 148 redds. Biological characteristics continue to suggest chum salmon in our study area are similar to nearby stocks in Hardy and Hamilton creeks, and Chinook salmon we observe are similar to upriver bright stocks. Temperature data indicated that 2004 brood URB fall Chinook salmon emergence began on 6 January and ended 27 May 2005, with peak emergence occurring 12 March. Chum salmon emergence began 4 February and continued through 2 May 2005, with peak emergence occurring on 21 March. Between 13 January and 28 June, we sampled 28,984 juvenile Chinook salmon and 1,909 juvenile chum salmon. We also released 32,642 fin-marked and coded-wire tagged juvenile fall Chinook salmon to assess survival. The peak catch of juvenile fall Chinook salmon occurred on 18 April. Our results suggested that the majority of fall Chinook salmon outmigrate during late May and early June, at 70-80 mm fork length (FL). The peak catch of juvenile chum salmon occurred 25 March. Juvenile chum salmon appeared to outmigrate at 40-55 mm FL. Outmigration of chum salmon peaked in March but extended into April and May.

  11. Assessment of lake trout spawning habitat quality in central Lake Huron by submarine

    USGS Publications Warehouse

    Manny, Bruce A.; Edsall, Thomas A.

    1989-01-01

    Interstitial water quality was measured using a submersible at seven locations on Six Fathom Bank. Historically, the bank was an important lake trout spawning ground. It is currently the focus of coordinated, interagency efforts to rehabilitate lake trout in Lake Huron. Water quality, evaluated from measurements of biochemical oxygen demand, dissolved oxygen, ammonia, and hydrogen sulfide among the rocks, would not prevent lake trout eggs from hatching successfully on the bank.

  12. Extreme Inverted Trophic Pyramid of Reef Sharks Supported by Spawning Groupers.

    PubMed

    Mourier, Johann; Maynard, Jeffrey; Parravicini, Valeriano; Ballesta, Laurent; Clua, Eric; Domeier, Michael L; Planes, Serge

    2016-08-01

    The extent of the global human footprint [1] limits our understanding of what is natural in the marine environment. Remote, near-pristine areas provide some baseline expectations for biomass [2, 3] and suggest that predators dominate, producing an inverted biomass pyramid. The southern pass of Fakarava atoll-a biosphere reserve in French Polynesia-hosts an average of 600 reef sharks, two to three times the biomass per hectare documented for any other reef shark aggregations [4]. This huge biomass of predators makes the trophic pyramid inverted. Bioenergetics models indicate that the sharks require ∼90 tons of fish per year, whereas the total fish production in the pass is ∼17 tons per year. Energetic theory shows that such trophic structure is maintained through subsidies [5-9], and empirical evidence suggests that sharks must engage in wide-ranging foraging excursions to meet energy needs [9, 10]. We used underwater surveys and acoustic telemetry to assess shark residency in the pass and feeding behavior and used bioenergetics models to understand energy flow. Contrary to previous findings, our results highlight that sharks may overcome low local energy availability by feeding on fish spawning aggregations, which concentrate energy from other local trophic pyramids. Fish spawning aggregations are known to be targeted by sharks, but they were previously believed to play a minor role representing occasional opportunistic supplements. This research demonstrates that fish spawning aggregations can play a significant role in the maintenance of local inverted pyramids in pristine marine areas. Conservation of fish spawning aggregations can help conserve shark populations, especially if combined with shark fishing bans. PMID:27476598

  13. Sympatric spawning of Anguilla marmorata and Anguilla japonica in the western North Pacific Ocean.

    PubMed

    Kuroki, M; Aoyama, J; Miller, M J; Yoshinaga, T; Shinoda, A; Hagihara, S; Tsukamoto, K

    2009-06-01

    Extensive collections were made of the larvae of the temperate Japanese eel Anguilla japonica and the tropical giant mottled eel Anguilla marmorata in an overlapping area of the North Equatorial Current region of the western North Pacific Ocean. Collections of 189 A. marmorata and > 2500 A. japonica larvae during nine surveys from 1991 to 2007 showed that these two anguillid eels have similar spawning areas just west of the southern West Mariana Ridge. In July to August 2006 and August 2007, morphologically and genetically identified A. marmorata preleptocephali were mainly collected between 14.5-15 degrees N and 142-142.5 degrees E, where A. japonica preleptocephali were also caught in some of the same net tows. Fewer A. marmorata preleptocephali, however, were collected (n = 31) compared to those of A. japonica (n = c. 165), and fewer small larvae of A. marmorata were collected per tow than A. japonica (n = 1-10 and 1-294, respectively), suggesting relatively smaller spawning aggregations of A. marmorata. The distribution of preleptocephali and small larvae was wider in longitude in A. marmorata (131- 143 degrees E) than in A. japonica (137-143 degrees E), while the latitudinal range was almost the same (12-17 degrees N). Although spawning by these two species overlaps both spatially and temporally, the tropical eels of the North Pacific population of A. marmorata probably have a much longer spawning season with fewer spawners, at least in summer, and recruit to a much wider latitudinal range of growth habitats. PMID:20735676

  14. Using larval fish community structure to guide long-term monitoring of fish spawning activity

    USGS Publications Warehouse

    Pritt, Jeremy J.; Roseman, Edward F.; Ross, Jason E.; DeBruyne, Robin L.

    2015-01-01

    Larval fishes provide a direct indication of spawning activity and may therefore be useful for long-term monitoring efforts in relation to spawning habitat restoration. However, larval fish sampling can be time intensive and costly. We sought to understand the spatial and temporal structure of larval fish communities in the St. Clair–Detroit River system, Michigan–Ontario, to determine whether targeted larval fish sampling can be made more efficient for long-term monitoring. We found that larval fish communities were highly nested, with lower river segments and late-spring samples containing the highest genus richness of larval fish. We created four sampling scenarios for each river system: (1) using all available data, (2) limiting temporal sampling to late spring, (3) limiting spatial sampling to lower river segments only, and (4) limiting both spatial and temporal sampling. By limiting the spatial extent of sampling to lower river sites and/or limiting the temporal extent to the late-spring period, we found that effort could be reduced by more than 50% while maintaining over 75% of the observed and estimated total genus richness. Similarly, limiting the sampling effort to lower river sites and/or the late-spring period maintained between 65% and 93% of the observed richness of lithophilic-spawning genera and invasive genera. In general, community composition remained consistent among sampling scenarios. Targeted sampling offers a lower-cost alternative to exhaustive spatial and temporal sampling and may be more readily incorporated into long-term monitoring.

  15. Spawning period of Senegal sole, Solea senegalensis, based on juvenile otolith microstructure

    NASA Astrophysics Data System (ADS)

    Vinagre, Catarina; Maia, Anabela; Amara, Rachid; Cabral, Henrique N.

    2013-02-01

    The Senegal sole, Solea senegalensis, is a flatfish species distributed from the Bay of Biscay to the coast of South Africa. Although it is a species of high commercial value its spawning period remains poorly known. In the Tagus estuary, Portugal, two juvenile cohorts of this species colonize two independent nursery areas within the estuarine system. Left lapilli otoliths of these 0-group juveniles were used to estimate age and back-calculate hatch dates, thus allowing the estimation of S. senegalensis spawning period in the Portuguese coast. The two cohorts of S. senegalensis completed the colonization of the two nurseries in July. The ages of juveniles were estimated to range between 46 and 111 days in nursery A, and between 33 and 61 days in nursery B. Hatch dates ranged from April to early June for juveniles colonizing nursery A, and from May to early June for juveniles colonizing nursery B. The mean hatch date in nursery A was the 7th of May, while in nursery B it was the 25th of May. It was concluded that the spawning period for this species off the Portuguese coast was from April to June.

  16. Sound production by dusky grouper Epinephelus marginatus at spawning aggregation sites.

    PubMed

    Bertucci, F; Lejeune, P; Payrot, J; Parmentier, E

    2015-08-01

    Sound production by the dusky grouper Epinephelus marginatus was monitored both in captivity and at two Mediterranean spawning sites during the summers of 2012 and 2013. The results of long-term passive acoustic recordings provide for the first time a description of the sounds produced by E. marginatus. Two types of sounds were mainly recorded and consisted of low-frequency booms that can be produced singly or in series with dominant frequencies below 100 Hz. Recordings in captivity validated these sounds as belonging to E. marginatus and suggested that they may be associated with reproductive displays usually performed during early stages of courtship behaviour. This study also allowed the identification of a third, low-frequency growl-like type of sound typically found in other grouper species. These growls were, however, not recorded in tanks and it is cautiously proposed that they are produced by E. marginatus. Acoustic signals attributed to E. marginatus were produced throughout the spawning season, with a diel pattern showing an increase before dusk, i.e., from 1900 to 2200 hours, before decreasing until the morning. The occurrence of sounds during the spawning season of this species suggests that they are probably involved in social activity occurring close to aggregation sites. Passive acoustics offer a helpful tool to monitor aggregation sites of this emblematic species in order to improve conservation efforts. PMID:26177857

  17. Seasonal Abundance, Spatial Distribution, Spawning and Growth of Astropecten irregularis (Echinodermata: Asteroidea)

    NASA Astrophysics Data System (ADS)

    Freeman, S. M.; Richardson, C. A.; Seed, R.

    2001-07-01

    Seasonal trends in the abundance, spatial distribution, spawning and growth of a population of Astropecten irregularis inhabiting the coastal waters of North Wales are described. Population densities of A. irregularis varied seasonally with starfish attaining their maximum and minimum abundances in summer and winter respectively. Changes in their spatial distribution strongly suggests that A. irregularis migrates offshore into deeper waters during the winter months probably to avoid strong onshore wave surges. High population densities of starfish which occur during the summer months may be associated with spawning aggregations or the availability of suitable prey species; a smaller peak in starfish abundance occurred during autumn 1997 coinciding with the settlement of the bivalve Spisula subtruncata and the cumacean Diastylis rugosa , prey species which are readily consumed by A. irregularis. Astropecten irregularis spawned during late spring-early summer, but thereafter the gonad somatic index remained at a low level until late autumn; the index increased throughout winter and starfish attained peak reproductive condition by late spring. Small starfish (arm length <24 mm), showed little evidence of reproductive development. Limited recruitment of A. irregularis (<8 mm) occurred during October-November 1996, and the integration of this small cohort into the main population occurred within one year. Locomotory activity and burrowing depth of starfish maintained in laboratory aquaria correlated with changes in seawater temperature; activity was largely inhibited and burrowing depth significantly increased at temperatures <8 °C. Seawater temperature is probably an important factor regulating the abundance and distribution of A. irregularis in coastal waters.

  18. Signaling cascades and the importance of moonlight in coral broadcast mass spawning

    PubMed Central

    Kaniewska, Paulina; Alon, Shahar; Karako-Lampert, Sarit; Hoegh-Guldberg, Ove; Levy, Oren

    2015-01-01

    Many reef-building corals participate in a mass-spawning event that occurs yearly on the Great Barrier Reef. This coral reproductive event is one of earth's most prominent examples of synchronised behavior, and coral reproductive success is vital to the persistence of coral reef ecosystems. Although several environmental cues have been implicated in the timing of mass spawning, the specific sensory cues that function together with endogenous clock mechanisms to ensure accurate timing of gamete release are largely unknown. Here, we show that moonlight is an important external stimulus for mass spawning synchrony and describe the potential mechanisms underlying the ability of corals to detect environmental triggers for the signaling cascades that ultimately result in gamete release. Our study increases the understanding of reproductive chronobiology in corals and strongly supports the hypothesis that coral gamete release is achieved by a complex array of potential neurohormones and light-sensing molecules. DOI: http://dx.doi.org/10.7554/eLife.09991.001 PMID:26668113

  19. Original research in the classroom: why do zebrafish spawn in the morning?

    PubMed

    Liang, Jennifer O; Abata, Katie; Bachelder, Eric; Bartley, Becca; Bozadjieva, Nadejda; Caskey, Victoria; Christianson, Benjamin; Detienne, Shannon; Dillon, Cassandra; Ecklund, Derek; Eckwright, David; Erickson, Raymond; Fadness, Tyler; Fealey, Michael; Fetter, Nicholas; Flatten, Michael; Fulton, Joshua; Galloway, Ryan; Gauer, Jacob; Hagler, Michael; Hammer, Andrea; Hasbargen, David; Heckmann, Brandon; Hildebrandt, Anne; Hillesheim, Jaclyn; Hoffman, Meghan; Hovey, Jonathan; Iverson, Sonja; Joyal, Matthew; Jubran, Rami; Keller, Stephanie; Kent, Derek; Kiefer, Brendan; King, Jacob; Kuefler, Aaron; Larson, Alex; Lewis, Nathan; Lu, Po-nien; Malone, Jessica; Mickolichek, Chelsey; Mitchell, Sean; Nelson, Pamela; Nemec, Michelle; Olsen, Shayna; Olson, Kendelle; Pautz, Kelsey; Pieper, Kelsey; Remackel, Michelle; Rengo, Cody; Sekenski, Jaime; Sievers, Tyson; Slavik, Brittney; Sloan, Jami; Smrekar, Candice; Stromquist, Emily; Tandberg, Patrick; Taurinskas, Nicholas; Thiele, Mark; Timinski, Peter; Tusa, Barite; Tuthill, Andrew; Uher, Bradley; Ward, Amy; Wilson, Luke; Young, Nathan

    2011-12-01

    As part of an upper level undergraduate developmental biology course at the University of Minnesota Duluth, we developed a unit in which students carried out original research as part of a cooperative class project. Students had the opportunity to gain experience in the scientific method from experimental design all of the way through to the preparation of publication on their research that included text, figures, and tables. This kind of inquiry-based learning has been shown to have many benefits for students, including increased long-term learning and a better understanding of the process of scientific discovery. In our project, students designed experiments to explore why zebrafish typically spawn in the first few hours after the lights come on in the morning. The results of our experiments suggest that spawning still occurs when the dark-to-light transition is altered or absent. This is consistent with the work of others that demonstrates that rhythmic spawning behavior is regulated by an endogenous circadian clock. Our successes and failures carrying out original research as part of an undergraduate course should contribute to the growing approaches for using zebrafish to bring the excitement of experimental science to the classroom. PMID:22181662

  20. Evolution of sperm morphology in anurans: insights into the roles of mating system and spawning location

    PubMed Central

    2014-01-01

    Background The degree of postcopulatory sexual selection, comprising variable degrees of sperm competition and cryptic female choice, is an important evolutionary force to influence sperm form and function. Here we investigated the effects of mating system and spawning location on the evolution of sperm morphology in 67 species of Chinese anurans. We also examined how relative testes size as an indicator of the level of sperm competition affected variation in sperm morphology across a subset of 29 species. Results We found a significant association of mating system and spawning location with sperm morphology. However, when removing the effects of body mass or absolute testes mass for species for which such data were available, this effect became non-significant. Consistent with predictions from sperm competition theory, we found a positive correlation between sperm morphology and relative testes size after taking phylogeny into account. Conclusions Our findings suggest that sexual selection in Chinese anurans favors longer sperm when the level of sperm competition is high. Pre-copulatory male-male competition and spawning location, on the other hand, do not affect the evolution of sperm morphology after taking body mass and absolute testes mass into account. PMID:24884745

  1. Dairy Wastewater, Aquaculture, and Spawning Fish as Sources of Steroid Hormones in the Aquatic Environment

    NASA Astrophysics Data System (ADS)

    Kolodziej, E. P.; Harter, T.; Sedlak, D. L.

    2004-12-01

    A suite of androgens, estrogens, and progestins were measured in samples from dairy farms, aquaculture facilities, and surface waters with actively spawning fish using gas chromatography-tandem mass spectrometry (GC/MS/MS) to assess the potential importance of these sources of steroid hormones to surface waters. In a dairy waste lagoon, the endogenous estrogens 17beta-estradiol and estrone, and the androgens testosterone and androstenedione were detected at concentrations as high as 650 ng/L. Samples from nearby groundwater monitoring wells demonstrated removal of steroid hormones in the subsurface. Samples from nearby surface waters and tile drains likely impacted by animal wastes demonstrated the sporadic presence of the steroids 17beta-estradiol, estrone, testosterone, and medroxyprogesterone, usually at concentrations near or below 1 ng/L. The endogenous steroids estrone, testosterone, and androstenedione were detected in the raceways and effluents of three fish hatcheries at concentrations near 1 ng/L. Similar concentrations were detected in a river containing spawning adult Chinook salmon. These results indicate that dairy wastewater, aquaculture effluents, and even spawning fish are sources that can lead to detectable concentrations of steroid hormones in surface waters and that the concentrations of these compounds exhibit considerable temporal and spatial variation.

  2. Reproductive neuropeptides that stimulate spawning in the Sydney Rock Oyster (Saccostrea glomerata).

    PubMed

    In, Vu Van; Ntalamagka, Nikoleta; O'Connor, Wayne; Wang, Tianfang; Powell, Daniel; Cummins, Scott F; Elizur, Abigail

    2016-08-01

    The Sydney Rock Oyster, Saccostrea glomerata, is a socioeconomically important species in Australia, yet little is known about the molecular mechanism that regulates its reproduction. To address this gap, we have performed a combination of high throughput transcriptomic and peptidomic analysis, to identify genes and neuropeptides that are expressed in the key regulatory tissues of S. glomerata; the visceral ganglia and gonads. Neuropeptides are known to encompass a diverse class of peptide messengers that play functional roles in many aspects of an animal's life, including reproduction. Approximately 28 neuropeptide genes were identified, primarily within the visceral ganglia transcriptome, that encode precursor proteins containing numerous neuropeptides; some were confirmed through mass spectral peptidomics analysis of the visceral ganglia. Of those, 28 bioactive neuropeptides were synthesized, and then tested for their capacity to induce gonad development and spawning in S. glomerata. Egg laying hormone, gonadotropin-releasing hormone, APGWamide, buccalin, CCAP and LFRFamide were neuropeptides found to trigger spawning in ripe animals. Additional testing of APGWa and buccalin demonstrated their capacity to advance conditioning and gonadal maturation. In summary, our analysis of S. glomerata has identified neuropeptides that can influence the reproductive cycle of this species, specifically by accelerating gonadal maturation and triggering spawning. Other molluscan neuropeptides identified in this study will enable further research into understanding the neuroendocrinology of oysters, which may benefit their cultivation. PMID:27328253

  3. Effects of telemetry transmitter placement on egg retention in naturally spawning, captively reared steelhead

    SciTech Connect

    Berejikian, Barry A.; Brown, Richard S.; Tatara, Chris P.; Cooke, Steven J.

    2007-05-01

    Maturing female anadromous salmonids receiving surgical intraperitoneally-implanted telemetry transmitters may experience difficulty depositing eggs during natural spawning. We allocated maturing adult steelhead females to three treatments: tags surgically implanted in the body cavity (internal), tags implanted between the skin and muscle tissue (subdermal), and non-tagged, and allowed them to spawn naturally in an experimental channel. Internally tagged females retained significantly more eggs than both the subdermally tagged treatment (P = 0.005) and non-tagged controls (P = 0.001); the subdermal and non-tag controls did not differ significantly (P = 0.934). The internal, subdermal and non-tag treatments retained an average of 49%, 11% and 2% of their eggs, respectively. The onset of sexual activity did not differ significantly among treatments (P = 0.413). Post-spawning mortality was 70% for both internally and subdermally tagged females and 0% for non-tagged females (P <0.01). We suggest that subdermal implantation techniques be considered in future studies during the reproductive period to reduce egg retention caused by internal implantation of transmitters.

  4. Temporal windows of reproductive opportunity reinforce species barriers in a marine broadcast spawning assemblage.

    PubMed

    Monteiro, Carla A; Paulino, Cristina; Jacinto, Rita; Serrão, Ester A; Pearson, Gareth A

    2016-01-01

    Prezygotic isolating mechanisms act to limit hybridization and maintain the genetic identity of closely-related species. While synchronous intraspecific spawning is a common phenomenon amongst marine organisms and plays an important role in reproductive success, asynchronous spawning between potentially hybridizing lineages may also be important in maintaining species boundaries. We tested this hypothesis by comparing reproductive synchrony over daily to hourly timescales in a sympatric assemblage of intertidal fucoid algae containing selfing hermaphroditic (Fucus spiralis and Fucus guiryi) and dioecious (Fucus vesiculosus and Fucus serratus) species. Our results confirm that gametes are released on semi-lunar cycles in all species. However, sister species with different mating systems showed asynchronous spawning at finer circadian timescales, thus providing evidence for a partial reproductive barrier between hermaphroditic and dioecious species. Finally, our data also emphasize the ecological, developmental, and/or physiological constraints that operate to restrict reproduction to narrow temporal windows of opportunity in the intertidal zone and more generally the role of ecological factors in marine speciation. PMID:27373816

  5. Comparative mapping reveals quantitative trait loci that affect spawning time in coho salmon (Oncorhynchus kisutch)

    PubMed Central

    Araneda, Cristian; Díaz, Nelson F.; Gomez, Gilda; López, María Eugenia; Iturra, Patricia

    2012-01-01

    Spawning time in salmonids is a sex-limited quantitative trait that can be modified by selection. In rainbow trout (Oncorhynchus mykiss), various quantitative trait loci (QTL) that affect the expression of this trait have been discovered. In this study, we describe four microsatellite loci associated with two possible spawning time QTL regions in coho salmon (Oncorhynchus kisutch). The four loci were identified in females from two populations (early and late spawners) produced by divergent selection from the same base population. Three of the loci (OmyFGT34TUF, One2ASC and One19ASC) that were strongly associated with spawning time in coho salmon (p < 0.0002) were previously associated with QTL for the same trait in rainbow trout; a fourth loci (Oki10) with a suggestive association (p = 0.00035) mapped 10 cM from locus OmyFGT34TUF in rainbow trout. The changes in allelic frequency observed after three generations of selection were greater than expected because of genetic drift. This work shows that comparing information from closely-related species is a valid strategy for identifying QTLs for marker-assisted selection in species whose genomes are poorly characterized or lack a saturated genetic map. PMID:22888302

  6. Comparing histology and gonadosomatic index for determining spawning condition of small-bodied riverine fishes

    USGS Publications Warehouse

    Brewer, S.K.; Rabeni, C.F.; Papoulias, D.M.

    2008-01-01

    We compared gonadosomatic index (GSI) and histological analysis of ovaries for identifying reproductive periods of fishes to determine the validity of using GSI in future studies. Four small-bodied riverine species were examined in our comparison of the two methods. Mean GSI was significantly different between all histological stages for suckermouth minnow and red shiner. Mean GSI was significantly different between most stages for slenderhead darter; whereas stages 3 and 6 were not significantly different, the time period when these stages are present would allow fisheries biologists to distinguish between the two stages. Mean GSI was not significantly different for many histological stages in stonecat. Difficulties in distinguishing between histological stages and GSI associated with stonecat illustrate potential problems obtaining appropriate sample sizes from species that move to alternative habitats to spawn. We suggest that GSI would be a useful tool in identifying mature ovaries in many small-bodied, multiple-spawning fishes. This information could be combined with data from histology during mature periods to pinpoint specific spawning events. ?? 2007 Blackwell Munksgaard.

  7. Foraging behaviors of Surf Scoters and White-Winged Scoters during spawning of Pacific herring

    USGS Publications Warehouse

    Esler, Daniel N.; Boyd, Sean

    2007-01-01

    Winter diets of Surf (Melanitta perspicillata) and White-winged Scoters (M. fusca) are composed primarily of bivalves. During spawning of Pacific herring (Clupea pallasi) in early spring, scoters shift their diets to herring eggs. Using radio-telemetry, we contrasted scoter foraging behaviorsbetween winter and herring spawning periods. Scoters increased their dive durations during herring spawning, likely to maximize the amount of roe consumed per dive; in winter, dives were typically terminated upon clam capture. Scoters spent approximately 50% less time foraging ( $min underwater hr^{-1}$ ) and decreased their dive rate (dives hr -1 ) by 70% when feeding on roe. The observed reduction in time spent foraging was presumably caused by the abundance of herring eggs, and thus a reduction in prey search-time. Scoters were able to meet energetic requirements with reduced effort, despite potentially increased demands related to spring fattening. Less time spentforaging may also allow more time for premigratory courtship behaviors

  8. Temporal windows of reproductive opportunity reinforce species barriers in a marine broadcast spawning assemblage

    PubMed Central

    Monteiro, Carla A.; Paulino, Cristina; Jacinto, Rita; Serrão, Ester A.; Pearson, Gareth A.

    2016-01-01

    Prezygotic isolating mechanisms act to limit hybridization and maintain the genetic identity of closely-related species. While synchronous intraspecific spawning is a common phenomenon amongst marine organisms and plays an important role in reproductive success, asynchronous spawning between potentially hybridizing lineages may also be important in maintaining species boundaries. We tested this hypothesis by comparing reproductive synchrony over daily to hourly timescales in a sympatric assemblage of intertidal fucoid algae containing selfing hermaphroditic (Fucus spiralis and Fucus guiryi) and dioecious (Fucus vesiculosus and Fucus serratus) species. Our results confirm that gametes are released on semi-lunar cycles in all species. However, sister species with different mating systems showed asynchronous spawning at finer circadian timescales, thus providing evidence for a partial reproductive barrier between hermaphroditic and dioecious species. Finally, our data also emphasize the ecological, developmental, and/or physiological constraints that operate to restrict reproduction to narrow temporal windows of opportunity in the intertidal zone and more generally the role of ecological factors in marine speciation. PMID:27373816

  9. Hierarchical Bayesian Markov switching models with application to predicting spawning success of shovelnose sturgeon

    USGS Publications Warehouse

    Holan, S.H.; Davis, G.M.; Wildhaber, M.L.; DeLonay, A.J.; Papoulias, D.M.

    2009-01-01

    The timing of spawning in fish is tightly linked to environmental factors; however, these factors are not very well understood for many species. Specifically, little information is available to guide recruitment efforts for endangered species such as the sturgeon. Therefore, we propose a Bayesian hierarchical model for predicting the success of spawning of the shovelnose sturgeon which uses both biological and behavioural (longitudinal) data. In particular, we use data that were produced from a tracking study that was conducted in the Lower Missouri River. The data that were produced from this study consist of biological variables associated with readiness to spawn along with longitudinal behavioural data collected by using telemetry and archival data storage tags. These high frequency data are complex both biologically and in the underlying behavioural process. To accommodate such complexity we developed a hierarchical linear regression model that uses an eigenvalue predictor, derived from the transition probability matrix of a two-state Markov switching model with generalized auto-regressive conditional heteroscedastic dynamics. Finally, to minimize the computational burden that is associated with estimation of this model, a parallel computing approach is proposed. ?? Journal compilation 2009 Royal Statistical Society.

  10. Long-term Monitoring of Spawning Habitat Rehabilitation Projects in a Regulated River

    NASA Astrophysics Data System (ADS)

    Wheaton, J. M.; Brasington, J.; Darby, S. E.; Merz, J.; Pasternack, G.; Sear, D.; Vericat, D.

    2009-04-01

    Monitoring geomorphic changes in response to river restoration interventions through the use of repeat topographic surveying is becoming more common in long-term monitoring programs. Repeat montitoring surveys are often preformed before and immediately following construction, and then on some defined interval (typically annually) or event-basis. How uncertainties in these surveys are managed to decipher what changes can be taken as meaningful adjustments of the project and/or geomorphic changes versus just noise in the data requires careful consideration. Moreover, once the reliability of the data is reasonably well understood, how to interpret the changes and segregate the resulting sediment budgets has not received adequate attention in the literature. Here, eight repeat topographic surveys from four different spawning habitat rehabilitation projects on the heavily Mokelumne River of California, are used to demonstrate the utility of applying some new methods for accounting for DEM reliability uncertainties and budget segregation techniques. The significance of recorded geomorphic changes are related to spawning and incubating Chinook salmon (Oncorhynchus tshawytsch) to explore questions such as: 1) the impact of a large flood on incubating salmonids embryos; 2) the influence of high-flow dam releases on physical habitat quality; and 3) documenting changes that took place specifically where salmon spawned. The results highlight some simple but interpretively powerful techniques for linking ecohydraulic and geomorphic field monitoring data at a scale relevant to salmon.

  11. Spawning segregation and philopatry are major prezygotic barriers in sympatric cryptic Mugil cephalus species.

    PubMed

    Shen, Kang-Ning; Chang, Chih-Wei; Durand, Jean-Dominique

    2015-12-01

    The flathead mullet, Mugil cephalus, is a commercially vital fish in fisheries and aquaculture worldwide. Genetic analyses have recently revealed three cryptic species of M. cephalus in the Northwest Pacific. These species are sympatric in Taiwanese waters and specific reproductive behaviors have been suggested to be a major prezygotic barrier. Species composition was evaluated in samples of M. cephalus at different growth stages collected from various habitats (offshore spawning ground, estuarine nursery and feeding areas) over several months or years. The gonadosomatic index of adults and the body length of juveniles were recorded to determine the reproductive season and recruitment periods in estuaries. The results revealed partially temporal spawning isolation between species pairs, spatial segregation on specific spawning grounds and strong philopatry preclude hybridization. Thus, the results imply that traditional fisheries of mature fish in the Taiwan Strait target only one species, whereas aquaculture in Taiwan contain juveniles of all three species collected in estuaries. The ecological niche and demography of these species must be investigated further to estimate the impact of juvenile sources on aquaculture. PMID:26563557

  12. Tradeoffs between homing and habitat quality for spawning site selection by hatchery-origin Chinook salmon

    USGS Publications Warehouse

    Cram, Jeremy M.; Torgersen, Christian E.; Klett, Ryan S.; Pess, George R.; May, Darran; Pearsons, Todd N.; Dittman, Andrew H.

    2013-01-01

    Spawning site selection by female salmon is based on complex and poorly understood tradeoffs between the homing instinct and the availability of appropriate habitat for successful reproduction. Previous studies have shown that hatchery-origin Chinook salmon (Oncorhynchus tshawytscha) released from different acclimation sites return with varying degrees of fidelity to these areas. To investigate the possibility that homing fidelity is associated with aquatic habitat conditions, we quantified physical habitat throughout 165 km in the upper Yakima River basin (Washington, USA) and mapped redd and carcass locations from 2004 to 2008. Principal components analysis identified differences in substrate, cover, stream width, and gradient among reaches surrounding acclimation sites, and canonical correspondence analysis revealed that these differences in habitat characteristics were associated with spatial patterns of spawning (p < 0.01). These analyses indicated that female salmon may forego spawning near their acclimation area if the surrounding habitat is unsuitable. Evaluating the spatial context of acclimation areas in relation to surrounding habitat may provide essential information for effectively managing supplementation programs and prioritizing restoration actions.

  13. Identification of the Spawning, Rearing, and Migratory Requirements of Fall Chinook Salmon in the Columbia River Basin, Annual Report 1993.

    SciTech Connect

    Rondorf, Dennis W.; Tiffan, Kenneth F.

    1994-12-01

    Recovery efforts for the endangered fall chinook salmon necessitates knowledge of the factors limiting the various life history stages. This study attempts to identify those physical and biological factors which affect spawning of the fish in the free-flowing Snake River and their rearing seward migration through Columbia River basin reservoirs. The spawning was generally a November event in 1993, with some activity in late Oct. and early Dec. Spawning habitat availability was assessed by applying hydraulic and habitat models to known fall chinook salmon spawning sites. Juveniles were seined and PIT tagged in the free-flowing Snake River, and in the Columbia River in he Hanford Reach and in McNary Reservoir. Subyearling fish were marked at McNary Dam to relate river flow and migration patterns of juveniles to adult returns. Hydroacoustic surveys were conducted on McNary and John Day reservoirs and in net pens.

  14. METHODS FOR SPAWNING, CULTURING, AND CONDUCTING TOXICITY TESTS WITH EARLY-LIFE STAGES OF ESTUARINE AND MARINE FISHES

    EPA Science Inventory

    This chapter provides a detailed description of the life history, geographical distribution of the life history, geographical distribution, and procedures for laboratory spawning, culturing and testing of five fishes: the sheepshead minnow, Cyprinodon variegatus; the inlan...

  15. Appearance and quantification of infectious hematopoietic necrosis virus in female sockeye salmon (Oncorhynchus nerka) during their spawning migration

    USGS Publications Warehouse

    Mulcahy, D.; Jenes, C.K.; Pascho, R.J.

    1984-01-01

    The incidence and amount of infectious hematopoietic necrosis (IHN) virus was determined in 10 organs and body fluids from each of 100 female sockeye salmon(Oncorhynchus nerka) before, during, and after their spawning migration into freshwater. Virus was found in high concentrations only in fish sampled during and after spawning. Infection rates increased from nil to 100 percent within 2 weeks. In spawning fish, incidences of IHN virus were high in all organs and fluids except brain and serum, and the highest concentrations were in the pyloric caeca and lower gut. Immediately before spawning, IHN virus was found most frequently in the gills, less frequently in the pyloric caeca and spleen, and rarely in other organs.

  16. Effect of mesoscale eddies and streamers on sardine spawning habitat and recruitment success off Southern and central California

    NASA Astrophysics Data System (ADS)

    Nieto, Karen; McClatchie, Sam; Weber, Edward D.; Lennert-Cody, Cleridy E.

    2014-09-01

    We quantified the effect of mesoscale eddies and streamers on the spatial distribution of Pacific sardine spawning habitat using a merged altimetry data set and a statistical spawning habitat model. The distribution of eggs could be predicted using sea-surface temperature, chlorophyll concentration, and eddy kinetic energy (EKE) similarly to previous studies. Eddies alone did not have a significant additional or emergent effect on the probability of capturing eggs beyond these predictors. Rather, mesoscale features (eddies and streamers) entrained water with the appropriate conditions in terms of temperature, chlorophyll, and EKE. These dynamic features moved appropriate spawning habitat for sardine offshore to areas where appropriate habitat otherwise would not exist. Using centroids of predicted sardine habitat, we showed that sardine recruitment success was inversely correlated with distance from shore of predicted sardine habitat centroids. This indicates that offshore transport has a negative effect on sardine recruitment, despite expanding favorable spawning habitat further offshore.

  17. Determination of temporal spawning patterns and hatching time in response to temperature of Atlantic bluefin tuna (Thunnus thynnus) in the Western Mediterranean.

    PubMed

    Gordoa, Ana; Carreras, Gustavo

    2014-01-01

    This study analysed the temporal pattern of Atlantic bluefin tuna (ABFT) spawning in the Balearic spawning ground and examined its reproductive performance after years in captivity. Furthermore, ABFT hatching time at different on-site temperatures was determined for the first time. Spawning surveys were carried out in 4 spawning seasons (2009-2012) aboard tuna transport vessels. Three groups of spawners were monitored: a captive group transported to the spawning region and monitored throughout the four spawning seasons and two wild groups caught in 2009 and 2010 which were transferred to a monitoring transport cage immediately after being caught. Surface plankton samples were collected nightly, beginning immediately after the first purse seine catches were made and concluding after spawning was observed to have ended. All groups displayed the same spawning hours, restricted between 2:00-5:00 a.m. The captive group, as they got older, shifted towards the earliest hour, suggesting an age influence on reproductive time. The onset of spawning varied annually from the end of May to the beginning of June at temperatures around 19 °C-20 °C, ending by the second week of July. The peak of spawning was consistently around the summer solstice, June 15th-30th. The results showed the negative effect of unstable oceanographic conditions in the spawning process which might influence the annual reproductive success of ABFT. The influence of temperature on hatching time was higher than that observed in other tuna species, twice as fast at 26 °C (23 h) as at 19.5 °C (49 h). Overall, this study shows the strength of the internal mechanism in ABFT that controls spawning traits. Spawning in ABFT is cyclical and highly synchronised on diel and annual scales. We consider that the timing of spawning is rather influenced by day length and its adaptive significance is discussed. PMID:24608107

  18. Determination of Temporal Spawning Patterns and Hatching Time in Response to Temperature of Atlantic Bluefin Tuna (Thunnus thynnus) in the Western Mediterranean

    PubMed Central

    Gordoa, Ana; Carreras, Gustavo

    2014-01-01

    This study analysed the temporal pattern of Atlantic bluefin tuna (ABFT) spawning in the Balearic spawning ground and examined its reproductive performance after years in captivity. Furthermore, ABFT hatching time at different on-site temperatures was determined for the first time. Spawning surveys were carried out in 4 spawning seasons (2009–2012) aboard tuna transport vessels. Three groups of spawners were monitored: a captive group transported to the spawning region and monitored throughout the four spawning seasons and two wild groups caught in 2009 and 2010 which were transferred to a monitoring transport cage immediately after being caught. Surface plankton samples were collected nightly, beginning immediately after the first purse seine catches were made and concluding after spawning was observed to have ended. All groups displayed the same spawning hours, restricted between 2:00–5:00 a.m. The captive group, as they got older, shifted towards the earliest hour, suggesting an age influence on reproductive time. The onset of spawning varied annually from the end of May to the beginning of June at temperatures around 19°C–20°C, ending by the second week of July. The peak of spawning was consistently around the summer solstice, June 15th–30th. The results showed the negative effect of unstable oceanographic conditions in the spawning process which might influence the annual reproductive success of ABFT. The influence of temperature on hatching time was higher than that observed in other tuna species, twice as fast at 26°C (23 h) as at 19.5°C (49 h). Overall, this study shows the strength of the internal mechanism in ABFT that controls spawning traits. Spawning in ABFT is cyclical and highly synchronised on diel and annual scales. We consider that the timing of spawning is rather influenced by day length and its adaptive significance is discussed. PMID:24608107

  19. Gametogenic development and spawning of the freshwater clam, Galatea paradoxa (Born 1778) from the Volta River Estuary, Ghana.

    PubMed

    Adjei-Boateng, D; Wilson, J G

    2013-01-01

    The study focused on the reproductive cycle of Galatea paradoxa (Born 1778), a major species for artisanal fishery in the Volta River estuary, Ghana. Condition indices and histological observation of the gonads revealed that G. paradoxa has a single spawning event between July and October. Gametogenesis started in December progressing steadily to a peak in June-July when spawning began until November when individuals were spent. Condition and gonadal indices showed a clear relationship with the gametogenic stages. PMID:25141603

  20. Influence of water temperature on rainbow smelt spawning and early life history dynamics in St. Martin Bay, Lake Huron

    USGS Publications Warehouse

    O'Brien, Timothy P.; Taylor, William W.; Briggs, Andrew S.; Roseman, Edward F.

    2012-01-01

    Rainbow smelt are an important prey species for native and introduced salmonines in the Great Lakes. In Lake Huron, rainbow smelt populations are characterized by variable recruitment and year-class strength. To understand the influence of water temperature on reproduction, growth, and survival during larval-fish stages, we sampled spawning tributaries and larval-fish habitats during 2008 and 2009 in St. Martin Bay, Lake Huron. Spawning by rainbow smelt occurred primarily when stream temperatures were between 3 and 10 °C, which resulted in a 7–10-day spawning period during 2008, and a 15–20-day spawning period during 2009. Regardless of these differences in spawning temperatures and duration, peak larval-fish densities during 2008 were double those observed during 2009. Length–frequency analysis of larval-fish populations during both years revealed stream-hatched fish during May and a later emergence of larval rainbow smelt during summer, presumably originating from lake spawning. Warmer bay water temperatures led to earlier emergence of lake-spawned rainbow smelt larvae during 2009. Stream-hatched fish larvae experienced large-scale mortality during May 2008 resulting in a bay population consisting primarily of lake-spawned rainbow smelt larvae, but during 2009 both stream- and lake-hatched cohorts experienced higher survival concomitant with significantly higher mean population growth rates. Higher larval-fish growth rates during 2009 appeared to be density-dependent and facilitated by warmer water temperatures during late June and cooler water temperatures during July. Temperature-mediated differences in annual growth rates and irregular contributions from stream- and lake-hatched fish larvae are important factors affecting survival and abundance of young-of-the-year rainbow smelt in Lake Huron.

  1. The description and histopathology of Leptorhynchoides polycristatus n. sp. (Acanthocephala: Rhadinorhynchidae) from sturgeons, Acipenser spp. (Actinopterygii: Acipenseridae) in the Caspian Sea, Iran, with emendation of the generic diagnosis.

    PubMed

    Amin, Omar M; Heckmann, Richard A; Halajian, Ali; El-Naggar, Atif M; Tavakol, Sareh

    2013-11-01

    Of the three known species of Leptorhynchoides Kostylew 1924, two are reported from North American fishes: Leptorhynchoides aphredoderi Buckner and Buckner 1976 and Leptorhynchoides thecatus (Linton 1891) Kostylew 1924. The third species, Leptorhynchoides plagicephalus (Westrumb 1821) Kostylew 1924, is commonly found in the Caspian and Black Sea from at least four species of sturgeons including Acipenser stellatus Pallas 1771 and the Acipenser nudiventris Lovetzsky 1828 from which Leptorhynchoides polycristatus n. sp. was found. No taxonomic work has been reported for L. plagicephalus for the last 90 years. L. polycristatus n. sp. can be readily confused with L. plagicephalus because of many superficial similarities. Such similarities include the general shape of the trunk, proboscis, and organ systems. However, L. polycristatus is clearly distinguished from the other three species primarily by having (1) 19-20 proboscis hooks per row; (2) the shortest hooks are anterior and the longest at the middle; the opposite is true in L. plagicephalus; (3) with a cuticular collar enveloping the base of the proboscis hooks; (4) the surface of its proboscis hooks is ribbed; (5) with a broad collar of multiple rectangular cuticular crests encircling the anterior end of the trunk; this is the only member of Leptorhynchoides with such a structure; (6) with many large ovoid uninucleated cells in the subcuticular layer of the trunk; (7) with paired glandular clusters near the male reproductive opening and of suction cup-like sensory structures on the bursa; (8) with dorsoventral ligament across the vagina; (9) cement glands are in a cluster of eight arranged in two horizontal tiers of four glands each; (10) with female gonopore near terminal; (11) with structures interpreted as possible microtriches on the surface of the trunk; (12) and with thinner eggs. L. polycristatus caused extensive histopathological damage to host intestinal layers. The armed proboscis invades and attaches

  2. Swimbladder function and the spawning migration of the European eel Anguilla anguilla.

    PubMed

    Pelster, Bernd

    2014-01-01

    The spawning migration of the European eel is an extensive journey over 5000 to 7000 km from the European coast to the Sargasso Sea. Eels do not feed during this journey and on-board fuels must be sufficient to support the journey of 3.5 to 6 month, as well as sexual maturation and the spawning activity. Swimming of eels appears to be quite energy efficient compared to other fish species, and elevated hydrostatic pressure has been shown to even reduce the costs of transport. Recent studies revealed, however, that during traveling eels perform extensive diurnal migrations and swim at a depth of about 100-300 m at night time, but go down to 600-1000 m at day time. At a depth of 200 m eels are exposed to a hydrostatic pressure of 21 atmospheres (2.13 MPa), while at 800 m hydrostatic pressure increases to 81 atmospheres (8.21 MPa). Accordingly, without any compensation at a depth of 800 m swimbladder volume will be reduced to about 25% of the volume established with neutral buoyancy at 200 m. Consequently, these diurnal changes in depth must be taken into consideration for a calculation of the energy requirements of the spawning migration. Without compensation a compression of the swimbladder will result in a status of negative buoyancy, which makes swimming more costly. Trying to keep the status of neutral buoyancy during descent by gas secretion into the swimbladder in turn requires metabolic activity to enhance swimbladder perfusion and for acid production of the gas gland cells to stimulate gas secretion. During ascent gas is passively removed from the swimbladder in the resorbing section and in the blood transported to the gills, where it is lost into the water. Accordingly, the swimbladder appears to be a crucial organ for the spawning migration. It can be assumed that an impairment of swimbladder function for example due to an infection with the nematode Anguillicola crassus significantly threatens the success of the spawning migration. PMID:25646080

  3. Recruitment of shrimp ( Pandalus borealis) in the Barents Sea related to spawning stock and environment

    NASA Astrophysics Data System (ADS)

    Aschan, Michaela; Ingvaldsen, Randi

    2009-10-01

    The shrimp spawn in autumn, and the females carry their eggs as out roe until spring when the larvae hatch. Within a period of 2 months the shrimp larvae settle to the bottom. It has been claimed that the year-class strength probably is determined during the larval phase. Today's assessment and forecast of the shrimp stock productivity and potential fishing yields are weak. This is partly due to poor knowledge on population dynamics from hatching until the shrimp are caught in the fishery at the age of 3 or 4 years. We, therefore, here identify the most important abiotic and biotic factors that affect recruitment in addition to spawning stock biomass. Since 1995, a net attached to the underbelly of the survey trawl used at the annual cruise in the Barents Sea has caught juvenile shrimp. The abundance of settled shrimp larvae varies in time and space. The recruitment to the fishery has been quite stable with the exception of the 1996 year-class, which was observed as 1-year-olds but has not been registered since. The temporal pattern of the three youngest year-classes is studied in relation to abiotic factors such as sea temperature, ice index and North Atlantic Oscillation, as well as biotic factors such as spawning stock biomass and presence of copepods, euphausiids and predating cod. Recruitment indices and factors identified by the Spearmann correlation to be significantly correlated with recruitment were used as input in a principal component analysis (PCA) and a generalized additive model (GAM) was applied. Abundance of 1-year-old shrimp is positively correlated to spawning stock biomass the previous year and to temperature of the previous winter, and negatively correlated with the number of 1-year-old cod. Two-year-old shrimp show significant correlation with temperature, whereas there is a strong negative correlation with euphausiids. Three-year-old shrimp are significantly correlated with the number of 2-year-old shrimp the previous year but negatively

  4. Swimbladder function and the spawning migration of the European eel Anguilla anguilla

    PubMed Central

    Pelster, Bernd

    2014-01-01

    The spawning migration of the European eel is an extensive journey over 5000 to 7000 km from the European coast to the Sargasso Sea. Eels do not feed during this journey and on-board fuels must be sufficient to support the journey of 3.5 to 6 month, as well as sexual maturation and the spawning activity. Swimming of eels appears to be quite energy efficient compared to other fish species, and elevated hydrostatic pressure has been shown to even reduce the costs of transport. Recent studies revealed, however, that during traveling eels perform extensive diurnal migrations and swim at a depth of about 100–300 m at night time, but go down to 600–1000 m at day time. At a depth of 200 m eels are exposed to a hydrostatic pressure of 21 atmospheres (2.13 MPa), while at 800 m hydrostatic pressure increases to 81 atmospheres (8.21 MPa). Accordingly, without any compensation at a depth of 800 m swimbladder volume will be reduced to about 25% of the volume established with neutral buoyancy at 200 m. Consequently, these diurnal changes in depth must be taken into consideration for a calculation of the energy requirements of the spawning migration. Without compensation a compression of the swimbladder will result in a status of negative buoyancy, which makes swimming more costly. Trying to keep the status of neutral buoyancy during descent by gas secretion into the swimbladder in turn requires metabolic activity to enhance swimbladder perfusion and for acid production of the gas gland cells to stimulate gas secretion. During ascent gas is passively removed from the swimbladder in the resorbing section and in the blood transported to the gills, where it is lost into the water. Accordingly, the swimbladder appears to be a crucial organ for the spawning migration. It can be assumed that an impairment of swimbladder function for example due to an infection with the nematode Anguillicola crassus significantly threatens the success of the spawning migration. PMID:25646080

  5. Comparisons of spawning areas and times for two runs of chinook salmon (Oncorhynchus tshawytscha) in the Kenai River, Alaska

    USGS Publications Warehouse

    Burger, C.V.; Wilmot, R.L.; Wangaard, D.B.

    1985-01-01

    From 1979 to 1982,188 chinook salmon (Oncorhynchus tshawytscha) were tagged with radio transmitters to locate spawning areas in the glacial Kenai River, southcentral Alaska. Results confirmed that an early run entered the river in May and June and spawned in tributaries, and a late run entered the river from late June through August and spawned in the main stem. Spawning peaked during August in tributaries influenced by lakes, but during July in other tributaries. Lakes may have increased fall and winter temperatures of downstream waters, enabling successful reproduction for later spawning fish within these tributaries. This hypothesis assumes that hatching and emergence can be completed in a shorter time in lake-influenced waters. The time of upstream migration and spawning (mid- to late August) of the late run is unique among chinook stocks in Cook Inlet. This behavior may have developed only because two large lakes (Kenai and Skilak) directly influence the main-stem Kenai River. If run timing is genetically controlled, and if the various components of the two runs are isolated stocks that have adapted to predictable stream temperatures, there are implications for stock transplantation programs and for any activities of man that alter stream temperatures.

  6. Observations on the spawning behavior, egg masses and paralarval development of the ommastrephid squid Todarodes pacificus in a laboratory mesocosm.

    PubMed

    Puneeta, Pandey; Vijai, Dharmamony; Yoo, Hae-Kyun; Matsui, Hajime; Sakurai, Yasunori

    2015-12-01

    The spawning behavior of ommastrephid squids has never been observed under natural conditions. Previous laboratory observations of Japanese flying squid (Todarodes pacificus) suggest that pre-spawning females might rest on the continental shelf or slope before they ascend above the pycnocline to spawn, and that the egg masses might settle in the pycnocline. Here, two mesocosm experiments were conducted in a 300 m(3) tank that was 6 m deep to investigate this hypothesis. In the first experiment, a thermocline (2.5-3.5 m) was established in the tank by creating a thermally stratified (17-22°C) water column. In the second experiment, the temperature was uniform (22°C) at all depths. Prior to spawning, females did not rest on the tank floor. In the stratified water column, egg masses remained suspended in the thermocline, but in an unstratified water column, they settled on the tank bottom, collapsed and were infested by microbes, resulting in abnormal or nonviable embryos. Eleven females spawned a total of 18 egg masses (17-80 cm in diameter), indicating that females can spawn more than once when under stress. Paralarvae hatched at stage 30/31 and survived for up to 10 days, allowing us to observe the most advanced stage of paralarvae in captivity. Paralarvae survived after consumption of the inner yolk, suggesting they might have fed in the tank. PMID:26632456

  7. Identification of the Spawning, Rearing, and Migratory Requirements of Fall Chinook Salmon in the Columbia River Basin, Annual Report 1994.

    SciTech Connect

    Rondorf, Dennis W.; Tiffan, Kenneth F.

    1996-08-01

    Spawning ground surveys were conducted in 1994 as part of a five year study of Snake River chinook salmon Oncorhynchus tshawyacha begun in 1991. Observations of fall chinook salmon spawning in the Snake River were limited to infrequent aerial red counts in the years prior to 1987. From 1987-1990, red counts were made on a limited basis by an interagency team and reported by the Washington Department of Fisheries. Starting in 1991, the U.S. Fish and Wildlife Service (USFWS), and other cooperating agencies and organizations, expanded the scope of spawning ground surveys to include: (1) additional aerial surveys to improve red counts and provide data on the timing of spawning; (2) the validation (ground truthing) of red counts from aerial surveys to improve count accuracy; (3) underwater searches to locate reds in water too deep to allow detection from the air; and (4) bathymetric mapping of spawning sites for characterizing spawning habitat. This document is the 1994 annual progress report for selected studies of fall chinook salmon. The studies were undertaken because of the growing concern about the declining salmon population in the Snake River basin.

  8. Do walleye pollock exhibit flexibility in where or when they spawn based on variability in water temperature?

    NASA Astrophysics Data System (ADS)

    Bacheler, Nathan M.; Ciannelli, Lorenzo; Bailey, Kevin M.; Bartolino, Valerio

    2012-06-01

    Environmental variability is increasingly recognized as a primary determinant of year-class strength of marine fishes by directly or indirectly influencing egg and larval development, growth, and survival. Here we examined the role of annual water temperature variability in determining when and where walleye pollock (Theragra chalcogramma) spawn in the eastern Bering Sea. Walleye pollock spawning was examined using both long-term ichthyoplankton data (N=19 years), as well as with historical spatially explicit, foreign-reported, commercial catch data occurring during the primary walleye pollock spawning season (February-May) each year (N=22 years in total). We constructed variable-coefficient generalized additive models (GAMs) to relate the spatially explicit egg or adult catch-per-unit-effort (CPUE) to predictor variables including spawning stock biomass, season, position, and water temperature. The adjusted R2 value was 63.1% for the egg CPUE model and 35.5% for the adult CPUE model. Both egg and adult GAMs suggest that spawning progresses seasonally from Bogoslof Island in February and March to Outer Domain waters between the Pribilof and Unimak Islands by May. Most importantly, walleye pollock egg and adult CPUE was predicted to generally increase throughout the study area as mean annual water temperature increased. These results suggest low interannual variability in the spatial and temporal dynamics of walleye pollock spawning regardless of changes in environmental conditions, at least at the spatial scale examined in this study and within the time frame of decades.

  9. Effects of thermal regime on ovarian maturation and plasma sex steroids in farmed white sturgeon, Acipenser transmontanus

    USGS Publications Warehouse

    Webb, M.A.H.; Van Eenennaam, J. P.; Feist, G.W.; Linares-Casenave, J.; Fitzpatrick, M.S.; Schreck, C.B.; Doroshov, S.I.

    2001-01-01

    Recently, commercial aquaculture farms in Northern California have exposed gravid, cultured white sturgeon females to cold water (12 ?? 1??C) throughout the late phase of vitellogenesis and ovarian follicle maturation resulting in improved ovulation rates and egg quality. However, the optimum timing for transfer of broodfish to the cold water and the capacity of transferred broodfish to maintain reproductive competence over an extended time in cold water had not been evaluated. Gravid white sturgeon females that have been raised at water temperatures of 16-20??C were transported to either cold water (12 ?? 1??C; Group 1) in November 1997 or maintained in ambient water temperatures (10-19??C; Group 2) until early spring. In March 1998, half of the fish in Group 2 had regressed ovaries, but the remaining females had intact ovarian follicles and were transported to the cold water. Ovarian follicles and blood were collected from females until they reached the stage of spawning readiness (determined by germinal vesicle position and an oocyte maturation assay) or underwent ovarian regression. Exposure of gravid sturgeon females to ambient water temperatures (14.5 ?? 2.3??C, mean ?? S.D.) from October to March led to a decrease in plasma sex steroids and a high incidence of ovarian regression in fish with a more advanced stage of oocyte development. Transfer of females with intact ovarian follicles to cold water (12 ?? 1??C) in the fall or early spring resulted in normal ovarian development in the majority of females. Holding females in cold water does not seem to override their endogenous reproductive rhythms but extends their capacity to maintain oocyte maturational competence over a longer period of time. A temperature-sensitive phase in ovarian development may occur during the transition from vitellogenic growth to oocyte maturation, and the degree and timing of sensitivity to environmental temperature are dependent on the female's endogenous reproductive rhythm

  10. An estimate of chinook salmon (Oncorhynchus tshawytscha) spawning habitat and redd capacity upstream of a migration barrier in the upper Columbia River

    SciTech Connect

    Hanrahan, Timothy P.; Dauble, Dennis D.; Geist, David R.

    2004-02-01

    Chief Joseph Dam on the Columbia River is the upstream terminus for anadromous fish, due to its lack of fish passage facilities. Management agencies are currently evaluating the feasibility of reintroducing anadromous fish upriver of Chief Joseph Dam. We evaluated the physical characteristics of potential fall chinook salmon (Oncorhynchus tshawytscha) spawning habitat in the upper section of Chief Joseph Reservoir. The objective of this study was to estimate the quantity and location of potential spawning habitat, and secondly to determine the redd capacity of the area based on spawning habitat characteristics. We used a geomorphic approach to first identify specific segments with the highest potential for spawning. The suitability of these segments for spawning was then estimated through the use of empirical physical data and modeled hydraulic data. We estimated 5% (48.7 ha) of the study area contains potentially suitable fall chinook salmon spawning habitat. Potential spawning habitat is primarily limited by water too deep and secondly by water velocities too low, the combination of which results in 20% (9.6 ha) of the potential spawning habitat being characterized as high quality. Estimates of redd capacity within potential spawning habitat range from 207? 1599 redds, based on proportional use of potential habitat and varying amounts of channelbed used by spawning salmon. The results of our study provide fisheries managers significant insight into one component of the complex issue of reintroducing anadromous fish to the Columbia River upstream of Chief Joseph Dam.

  11. Coupling Hydrodynamic Modeling and Empirical Measures of Bed Mobility: Implications for Restoring Spawning Gravel Quality on a Large Regulated River

    NASA Astrophysics Data System (ADS)

    May, C. L.; Smith, B. J.; Lisle, T. E.; Lang, M. M.

    2005-05-01

    Flow releases are increasingly being used as a tool to restore spawning gravel quality downstream of large dams. Often times, the primary goal of a peak flow release is to flush fine sediment from incubation habitat and restore active river processes; thus understanding the portion of the bed that is entrained and the flow required for full mobility is important. However, a critical knowledge gap for implementing these experimental floods is predicting the potential scouring of spawning redds in downstream reaches. To address these questions we need to understand the relationships between river discharge, bed mobility, and scour depths in areas heavily utilized by spawning salmon. Our approach couples numerical flow modeling and empirical data to quantify spatially explicit zones of differential bed mobility and identify specific areas where scour is deep enough to impact redd viability. Boundary shear stress values were predicted using the USGS's Multi-Dimensional Surface Water Modeling System for a segment of the Trinity River below Lewiston Dam. From model-generated shear stress and fine-scale mapping of local particle size distributions, Shields stress values were calculated to identify areas of differential bed mobility. Our data suggest that full mobility is limited to a central, yet discontinuous core along the thalweg, which expands with increasing flow strengths. Spatial analysis revealed that Chinook salmon tend not to spawn in areas that became fully mobile during bankfull flood events. Scour depths in areas preferentially used for spawning were less than in other portions of the bed and were not deep enough to impact incubating eggs or embryos. This site-selection preference allows fish to spawn in areas that are relatively safe from deep scour. However, the trade-off for spawning in stable areas is that flushing of fine sediment from the subsurface occurs very infrequently and gravel permeability is likely to become limiting for egg and embryo survival

  12. Long-term effects of intraperitoneal injection of estradiol-17β on the growth and physiology of juvenile stellate sturgeon Acipenser stellatus.

    PubMed

    Falahatkar, Bahram; Poursaeid, Samaneh; Meknatkhah, Bahman; Khara, Hossein; Efatpanah, Iraj

    2014-04-01

    Juvenile stellate sturgeon Acipenser stellatus were intraperitoneally injected with estradiol-17β (E2; 0 and 5 mg/kg fish) to investigate the possibility of sex reversal and also determine the changes in biochemical parameters. Five-month-old fish (40.9 ± 1.1 g) were injected every 3-week interval during a 190-day trial. At the termination of the experiment, final weight and other growth parameters including weight gain and specific growth rate, hepatosomatic and viscerosomatic indices were not affected by repetitive injection of E2. Hematological features of E2-treated fish showed significant reductions in number of red blood cells, hemoglobin concentration, hematocrit value and mean corpuscular hemoglobin (P < 0.05), but no significant changes were observed in number of white blood cells, mean corpuscular volume and mean corpuscular hemoglobin concentration (P > 0.05). Calcium, phosphorus, glucose, triacylglycerol, cholesterol, total protein and estradiol concentrations were significantly increased in fish injected with E2 (P < 0.001). Plasma progesterone and testosterone levels were noticeably lower in fish injected with 5 mg/kg E2 rather than the control fish (P < 0.001). Histological observations of gonads showed that all fish injected with 5 mg/kg E2 apparently feminized, while 66.6 % of the control group was female. These results revealed that the injection of E2 is an effective method for feminization of stellate sturgeon without having significant inhibitory effects on growth and survival. PMID:23990284

  13. Ancient fish and recent invaders: white sturgeon Acipenser transmontanus diet response to invasive-species-mediated changes in a benthic prey assemblage

    USGS Publications Warehouse

    Zeug, Steven C; Brodsky, Annie; Kogut, Nina; Stewart, Robin; Merz, Joe

    2014-01-01

    Invasive organisms can have significant impacts on native species, and the San Francisco Estuary (SFE), California, USA, is one of the world's most invaded estuaries. Decline of native white sturgeon Acipenser transmontanus abundance in the SFE has been acknowledged, but underlying mechanisms are poorly understood. Invasion by the overbite clam Potamocorbula amurensis has drastically altered the SFE benthic prey community, yet little is known about how this change has affected sturgeon diets. We investigated changes in the diet of white sturgeon following the overbite clam invasion and subsequent shift in the SFE benthic prey assemblage. Gut content analysis was used to compare white sturgeon prey composition and importance between the pre- and post-invasion periods. Additionally, stable isotope analysis was employed to estimate the assimilation of prey items to sturgeon biomass. Overbite clams dominated diets in the post-invasion period, accounting for 82 to 93% of total volume. Stable isotope analysis confirmed the importance of this prey item, although their assimilated contribution to sturgeon biomass was estimated to be less (70 to 83%) than gut contents indicated. The frequency of fish in white sturgeon guts increased in the post-invasion period, and isotope analysis indicated relatively large contributions of fish to sturgeon biomass (3.7 to 19%). The trophic adaptability of white sturgeon has allowed them to exploit this new prey source (overbite clam). Future conservation and restoration efforts must consider a potentially destabilized food web given the large importance of a single prey item.

  14. Adaptive alterations on gill Na⁺, K⁺-ATPase activity and mitochondrion-rich cells of juvenile Acipenser sinensis acclimated to brackish water.

    PubMed

    Zhao, Feng; Wu, Beibei; Yang, Gang; Zhang, Tao; Zhuang, Ping

    2016-04-01

    Understanding the physiological changes and osmoregulatory strategy is critical for anadromous species to adapt to large changes between freshwater and marine environments. In this study, juvenile Chinese sturgeon (Acipenser sinensis) were acclimated for 2 months to freshwater (FW, c. 0‰) and brackish water (BW, 15‰). Blood was assessed for changes in osmolality and ions. Gill tissue was assayed for Na(+), K(+)-ATPase (NKA) activity and immunohistochemical analysis on mitochondria-rich cells (MRCs). Serum osmolality and ions concentrations (Na(+), Cl(-) and K(+)) examined, except K(+), increased significantly in those specimens adapted to BW. However, the variations were within the range of effective hyperosmotic adaptation. The specific activity of gill NKA of juveniles adapted to BW was significantly higher (c. 1.6 times) than that of fish adapted to FW. MRCs were mainly presented in the interlamellar region of the filament and at the base of the lamella in either FW- or BW-acclimated individuals. In BW, the number and size of MRCs on filaments greatly increased. However, there was no significant difference in the number and size of the MRCs at the lamella region. Results show that juvenile Chinese sturgeon keep osmotic homeostasis in hyperosmotic environments by increasing gill NKA activity and MRCs' size and number, which is similar to other sturgeons and euryhaline teleosts. PMID:26614501

  15. Stock Structure and Homing Fidelity in Gulf of Mexico Sturgeon (Acipenser Oxyrinchus Desotoi) Based on Restriction Fragment Length Polymorphism and Sequence Analyses of Mitochondrial DNA

    PubMed Central

    Stabile, J.; Waldman, J. R.; Parauka, F.; Wirgin, I.

    1996-01-01

    Efforts have been proposed worldwide to restore sturgeon populations through the use of hatcheries to supplement natural reproduction and to reintroduce sturgeon where they have become extinct. We examined the population structure and inferred the extent of homing in the anadromous Gulf of Mexico (Gulf) sturgeon (Acipenser oxyrinchus desotoi). Restriction fragment length polymorphism and control region sequence analyses of mitochondrial DNA (mtDNA) were used to identify haplotypes of Gulf sturgeon specimens obtained from eight drainages spanning the subspecies' entire distribution from Louisiana to Florida. Significant differences in haplotype frequencies indicated substantial geographic structuring of populations. A minimum of four regional or river-specific populations were identified (from west to east): (1) Pearl River, LA and Pascagoula River, MS, (2) Escambia and Yellow rivers, FL, (3) Choctawhatchee River, FL, and (4) Apalachicola, Ochlockonee, and Suwannee rivers, FL. Estimates of maternally mediated gene flow between any pair of the four regional or river-specific stocks ranged between 0.15 to 1.2. Tandem repeats in the mtDNA control region of Gulf sturgeon were not perfectly conserved. This result, together with an absence of heteroplasmy and length variation in Gulf sturgeon mtDNA, indicates that the molecular mechanisms of mtDNA control region sequence evolution differ among acipenserids. PMID:8889537

  16. Characterization of the contents and histology of the gastrointestinal tracts of White Sturgeon (Acipenser transmontanus) captured from Upper Lake Roosevelt, Washington, October 2008

    USGS Publications Warehouse

    Parsley, Michael J.; van der Leeuw, Bjorn K.; Elliott, Diane G.

    2010-01-01

    The gastrointestinal tracts of 37 juvenile white sturgeon (Acipenser transmontanus) captured from the upper part of Lake Roosevelt during October 2008, were examined to identify prey taxa and to determine if the fish were consuming smelter slag along with other sediments. Histological examination of the gastrointestinal tract tissues and comparison with similar tissues from hatchery-reared fish also was performed. The contents of the gastro-intestinal tracts (guts) indicated that white sturgeon were actively foraging on various benthic invertebrates and the diet was quite diverse, with more than 50 percent of the fish feeding on five or more different taxa. Slag was present in 76 percent of the guts examined. Although not all guts contained slag particles, larger fish tended to have greater amounts of slag in their guts. Histology of the gut tissues showed the presence of a chronic inflammatory response, and the severity of the response had a significant positive correlation (P = 0.01) with fish length and weight suggesting that the inflammation represented a response to long-term exposure to one or more stressors. However, additional work is needed to determine if the physical or chemical properties of slag contributed to this response.

  17. Stock structure and homing fidelity in Gulf of Mexico sturgeon (Acipenser oxyrinchus desotoi) based on restriction fragment length polymorphism and sequence analyses of mitochondrial DNA.

    PubMed

    Stabile, J; Waldman, J R; Parauka, F; Wirgin, I

    1996-10-01

    Efforts have been proposed worldwide to restore sturgeon populations through the use of hatcheries to supplement natural reproduction and to reintroduce sturgeon where they have become extinct. We examined the population structure and inferred the extent of homing in the anadromous Gulf of Mexico (Gulf) sturgeon (Acipenser oxyrinchus desotoi). Restriction fragment length polymorphism and control region sequence analyses of mitochondrial DNA (mtDNA) were used to identify haplotypes of Gulf sturgeon specimens obtained from eight drainages spanning the subspecies' entire distribution from Louisiana to Florida. Significant differences in haplotype frequencies indicated substantial geographic structuring of populations. A minimum of four regional or river-specific populations were identified (from west to east): (1) Pearl River, LA and Pascagoula River, MS, (2) Escambia and Yellow rivers, FI, (3) Choctawbatchee River, FL and (4) Apalachicola Ochlockonee, and Suwannee rivers, FL. Estimates of maternally mediated gene flow between any pair of the four regional or river-specific stocks ranged between 0.15 to 1.2. Tandem repeats in the mtDNA control region of Gulf sturgeon were not perfectly conserved. This result, together with an absence of heteroplasmy and length variation in Gulf sturgeon mtDNA, indicates that the molecular mechanisms of mtDNA control region sequence evolution differ among acipenserids. PMID:8889537

  18. Effects of suspended sediment on the reproductive success of the tricolor shiner, a crevice-spawning minnow

    USGS Publications Warehouse

    Burkhead, N.M.; Jelks, H.L.

    2001-01-01

    Excessive sedimentation of rivers and creeks has been linked to increasing levels of imperilment in the diverse fish fauna of the southeastern United States. In particular, benthic-spawning fishes have decreased in both numbers and range. The tricolor shiner Cyprinella trichroistia is a crevice-spawning minnow that is widespread in the eastern Mobile River drainage above the Fall Line. While they are less sensitive to perturbation than the federally threatened blue shiner C. caerulea, tricolor shiners have decreased in numbers and range during the past few decades. This experiment examined the effects of 0 (control), 100, 300, and 600 mg/L initial concentrations of suspended sediment on the reproductive success of the tricolor shiner. Increasing levels of suspended sediment caused decreasing levels of reproductive success (fewer spawns and fewer eggs laid when spawning occurred). Increasing levels of suspended sediment also delayed the onset of spawning, resulting in distinct frequency distributions of clear eggs, eyed eggs, and larvae across treatments. Mortality of eggs and larvae was not a factor in the experiment. We examined daily sediment concentration data recorded at three sites in the upper Coosa River over the April-August spawning season of 1963. By weighting our experimental results by the number of days above each sediment concentration, we estimated that 20% fewer eggs were laid than would have been laid if conditions had been like those of the controls. Albeit our model is simplistic, it provides insight into how excessive sedimentation contributes to population extirpation. Mitigation of suspended sediments is an important management action for the conservation of southern Appalachian fishes that spawn in benthic habitats.

  19. Demographic structure, sex ratio and growth rates of southern bluefin tuna (Thunnus maccoyii) on the spawning ground.

    PubMed

    Farley, Jessica H; Eveson, J Paige; Davis, Tim L O; Andamari, Retno; Proctor, Craig H; Nugraha, Budi; Davies, Campbell R

    2014-01-01

    The demographics of the southern bluefin tuna (SBT) Thunnus maccoyii spawning stock were examined through a large-scale monitoring program of the Indonesian longline catch on the spawning ground between 1995 and 2012. The size and age structure of the spawning population has undergone significant changes since monitoring began. There has been a reduction in the relative abundance of larger/older SBT in the catch since the early 2000s, and a corresponding decrease in mean length and age, but there was no evidence of a significant truncation of the age distribution. Pulses of young SBT appear in the catches in the early- and mid-2000s and may be the first evidence of increased recruitment into the spawning stock since 1995. Fish in these two recruitment pulses were spawned around 1991 and 1997. Size-related variations in sex ratio were also observed with female bias for fish less than 170 cm FL and male bias for fish greater than 170 cm FL. This trend of increasing proportion of males with size above 170 cm FL is likely to be related to sexual dimorphism in growth rates as male length-at-age is greater than that for females after age 10 years. Mean length-at-age of fish aged 8-10 years was greater for both males and females on the spawning ground than off the spawning ground, suggesting that size may be the dominant factor determining timing of maturation in SBT. In addition to these direct results, the data and samples from this program have been central to the assessment and management of this internationally harvested stock. PMID:24797529

  20. Demographic Structure, Sex Ratio and Growth Rates of Southern Bluefin Tuna (Thunnus maccoyii) on the Spawning Ground

    PubMed Central

    Farley, Jessica H.; Eveson, J. Paige; Davis, Tim L. O.; Andamari, Retno; Proctor, Craig H.; Nugraha, Budi; Davies, Campbell R.

    2014-01-01

    The demographics of the southern bluefin tuna (SBT) Thunnus maccoyii spawning stock were examined through a large-scale monitoring program of the Indonesian longline catch on the spawning ground between 1995 and 2012. The size and age structure of the spawning population has undergone significant changes since monitoring began. There has been a reduction in the relative abundance of larger/older SBT in the catch since the early 2000s, and a corresponding decrease in mean length and age, but there was no evidence of a significant truncation of the age distribution. Pulses of young SBT appear in the catches in the early- and mid-2000s and may be the first evidence of increased recruitment into the spawning stock since 1995. Fish in these two recruitment pulses were spawned around 1991 and 1997. Size-related variations in sex ratio were also observed with female bias for fish less than 170 cm FL and male bias for fish greater than 170 cm FL. This trend of increasing proportion of males with size above 170 cm FL is likely to be related to sexual dimorphism in growth rates as male length-at-age is greater than that for females after age 10 years. Mean length-at-age of fish aged 8–10 years was greater for both males and females on the spawning ground than off the spawning ground, suggesting that size may be the dominant factor determining timing of maturation in SBT. In addition to these direct results, the data and samples from this program have been central to the assessment and management of this internationally harvested stock. PMID:24797529

  1. Effects of dam removal on Tule Fall Chinook salmon spawning habitat in the White Salmon River, Washington

    USGS Publications Warehouse

    Hatten, James R.; Batt, Thomas R.; Skalicky, Joseph J.; Engle, Rod; Barton, Gary J.; Fosness, Ryan L.; Warren, Joe

    2016-01-01

    Condit Dam is one of the largest hydroelectric dams ever removed in the USA. Breached in a single explosive event in October 2011, hundreds-of-thousands of cubic metres of sediment washed down the White Salmon River onto spawning grounds of a threatened species, Columbia River tule fall Chinook salmon Oncorhynchus tshawytscha. We investigated over a 3-year period (2010–2012) how dam breaching affected channel morphology, river hydraulics, sediment composition and tule fall Chinook salmon (hereafter ‘tule salmon’) spawning habitat in the lower 1.7 km of the White Salmon River (project area). As expected, dam breaching dramatically affected channel morphology and spawning habitat due to a large load of sediment released from Northwestern Lake. Forty-two per cent of the project area that was previously covered in water was converted into islands or new shoreline, while a large pool near the mouth filled with sediments and a delta formed at the mouth. A two-dimensional hydrodynamic model revealed that pool area decreased 68.7% in the project area, while glides and riffles increased 659% and 530%, respectively. A spatially explicit habitat model found the mean probability of spawning habitat increased 46.2% after dam breaching due to an increase in glides and riffles. Shifting channels and bank instability continue to negatively affect some spawning habitat as sediments continue to wash downstream from former Northwestern Lake, but 300 m of new spawning habitat (river kilometre 0.6 to 0.9) that formed immediately post-breach has persisted into 2015. Less than 10% of tule salmon have spawned upstream of the former dam site to date, but the run sizes appear healthy and stable. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  2. Spawn viability in edible mushrooms after freezing in liquid nitrogen without a cryoprotectant.

    PubMed

    Mata, Gerardo; Pérez-Merlo, Rosalía

    2003-08-01

    Five strains of edible mushrooms (Lentinula boryana, Lentinula edodes, Pleurotus djamor, Pleurotus pulmonarius, and Volvariella volvacea) were studied. Spawn were prepared from sorghum seeds and then incubated for 14 days under optimum conditions for each species. Once covered by mycelia, the sorghum seeds were placed in polycarbonate vials for freezing in liquid nitrogen. The effect of adding a cryoprotective solution before freezing (either 10% glycerol v/v or 5% dimethylsulfoxide v/v) was evaluated as a function of mycelial growth and percent viability. Three main treatments were undertaken: (1) freezing with a glycerol or dimethylsulfoxide cryoprotectant, (2) freezing with water and (3) freezing without cryoprotectant or water. Samples were maintained frozen for a week, after which time they were thawed (10 min at 30 degrees C) and the seeds placed in Petri dishes with a culture medium. A recovery rate of 96.8% was obtained for the total number of samples summed over all strains and treatments. In contrast, 99.2% of the samples frozen without cryoprotectant were recovered. The recovery of frozen mycelia was delayed with respect to a control group, which was not frozen. However, no difference was observed in percent recovery and mycelial diameter when a new series of spawn was prepared from mycelia that had been previously frozen. Results obtained from this experiment demonstrate that an adequate recovery of mycelia can be obtained without using a cryoprotectant. This capacity might enable large quantities of commercial mushroom strains to be handled at reduced production costs. It is suggested that the mycelia survived freezing without cryoprotectants because they were embedded and protected within the sorghum seeds used to elaborate the spawn. PMID:12963408

  3. Acoustic estimates of abundance and distribution of spawning lake trout on Sheboygan Reef in Lake Michigan

    USGS Publications Warehouse

    Warner, D.M.; Claramunt, R.M.; Janssen, J.; Jude, D.J.; Wattrus, N.

    2009-01-01

    Efforts to restore self-sustaining lake trout (Salvelinus namaycush) populations in the Laurentian Great Lakes have had widespread success in Lake Superior; but in other Great Lakes, populations of lake trout are maintained by stocking. Recruitment bottlenecks may be present at a number of stages of the reproduction process. To study eggs and fry, it is necessary to identify spawning locations, which is difficult in deep water. Acoustic sampling can be used to rapidly locate aggregations of fish (like spawning lake trout), describe their distribution, and estimate their abundance. To assess these capabilities for application to lake trout, we conducted an acoustic survey covering 22 km2 at Sheboygan Reef, a deep reef (<40 m summit) in southern Lake Michigan during fall 2005. Data collected with remotely operated vehicles (ROV) confirmed that fish were large lake trout, that lake trout were 1–2 m above bottom, and that spawning took place over specific habitat. Lake trout density exhibited a high degree of spatial structure (autocorrelation) up to a range of ~190 m, and highest lake trout and egg densities occurred over rough substrates (rubble and cobble) at the shallowest depths sampled (36–42 m). Mean lake trout density in the area surveyed (~2190 ha) was 5.8 fish/ha and the area surveyed contained an estimated 9500–16,000 large lake trout. Spatial aggregation in lake trout densities, similarity of depths and substrates at which high lake trout and egg densities occurred, and relatively low uncertainty in the lake trout density estimate indicate that acoustic sampling can be a useful complement to other sampling tools used in lake trout restoration research.

  4. Real-Time Ichthyoplankton Drift in Northeast Arctic Cod and Norwegian Spring-Spawning Herring

    PubMed Central

    Vikebø, Frode B.; Ådlandsvik, Bjørn; Albretsen, Jon; Sundby, Svein; Stenevik, Erling Kåre; Huse, Geir; Svendsen, Einar; Kristiansen, Trond; Eriksen, Elena

    2011-01-01

    Background Individual-based biophysical larval models, initialized and parameterized by observations, enable numerical investigations of various factors regulating survival of young fish until they recruit into the adult population. Exponentially decreasing numbers in Northeast Arctic cod and Norwegian Spring Spawning herring early changes emphasizes the importance of early life history, when ichthyoplankton exhibit pelagic free drift. However, while most studies are concerned with past recruitment variability it is also important to establish real-time predictions of ichthyoplankton distributions due to the increasing human activity in fish habitats and the need for distribution predictions that could potentially improve field coverage of ichthyoplankton. Methodology/Principal Findings A system has been developed for operational simulation of ichthyoplankton distributions. We have coupled a two-day ocean forecasts from the Norwegian Meteorological Institute with an individual-based ichthyoplankton model for Northeast Arctic cod and Norwegian Spring Spawning herring producing daily updated maps of ichthyoplankton distributions. Recent years observed spawning distribution and intensity have been used as input to the model system. The system has been running in an operational mode since 2008. Surveys are expensive and distributions of early stages are therefore only covered once or twice a year. Comparison between model and observations are therefore limited in time. However, the observed and simulated distributions of juvenile fish tend to agree well during early fall. Area-overlap between modeled and observed juveniles September 1st range from 61 to 73%, and 61 to 71% when weighted by concentrations. Conclusions/Significance The model system may be used to evaluate the design of ongoing surveys, to quantify the overlap with harmful substances in the ocean after accidental spills, as well as management planning of particular risky operations at sea. The modeled

  5. 2008 Spawning Cisco Investigations in the Canadian Waters of Lake Superior

    USGS Publications Warehouse

    Yule, Daniel; Addison, Peter A.; Evrard, Lori M.; Cullis, Ken I.; Cholwek, Gary A.

    2009-01-01

    The Great Lakes Science Center of the United States Geological Survey (USGS) is working cooperatively with the Ontario Ministry of Natural Resources (OMNR) on a threeyear study to develop standard procedures for acoustic and midwater trawl (AC-MT) assessments of spawning cisco Coregonus artedi that the OMNR can carry forward as a management activity. In year two (2008), we conducted an AC-MT survey of the northern shore from Nipigon Bay to Thunder Bay. Spawning-cisco (> 250 mm total length) densities were lowest near Nipigon Bay (<10/ha), moderate in and around Black Bay (15- 30/ha), and highest in Thunder Bay (118/ha). Rainbow smelt Osmerus mordax densities were highest in Nipigon (2,179/ha) and Black (3,219/ha) bays, and lowest in Thunder Bay (961/ha). We combined our AC-MT survey results with commercial catch records to estimate exploitation fractions of female cisco in Thunder Bay during the 2008 fishery at 4% for ages 1-5, 8.7% for ages 6-12, and 4.4% for ages ≥ 13. Lake Superior fishery managers recently recommended that annual exploitation of adult female lake cisco be kept below 10-15%. Recruitment of cisco since 2003 has been low and there is a strong probability the Thunder Bay stock will decline into the future. Using a simple population dynamics approach we estimated that if the current total allowable catch (TAC) quota is held constant, exploitation fractions could exceed 10% by 2010 and 15% by 2011. Our 2008 collections suggested the survey of Black Bay was likely conducted before all spawners had returned there to spawn. Our data also suggested that cisco collected in Black Bay and east of this site in mid-November may be from the same stock. During November 2009 we will attempt to get better definition of the area occupied by cisco around Black Bay and also determine when surveys should be conducted at this location.

  6. Spawning seasons of Rasbora tawarensis (Pisces: Cyprinidae) in Lake Laut Tawar, Aceh Province, Indonesia

    PubMed Central

    2010-01-01

    Background Rasbora tawarensis is an endemic freshwater fish in Lake Laut Tawar, Aceh Province, Indonesia. Unfortunately, its status is regarded as critical endangered with populations decreasing in recent years. To date no information on the spawning activities of the fish are available. Therefore, this study provides a contribution to the knowledge on reproductive biology of R. tawarensis especially on spawning seasons as well as basic information for conservation of the species. Methods Monthly sampling was conducted from April 2008 to March 2009 by using selective gillnets. The gonadosomatic index, size composition and sex ratio were assessed. The gonadal development was evaluated based on macroscopic and microscopic examinations of the gonads. Results The gonadosomatic index (GSI) varied between 6.65 to 18.16 in female and 4.94 to 8.56 for male. GSI of the female R. tawarensis was higher in March, September and December indicating the onset of reproductive seasons, the GSI and oocyte size being directly correlated with gonadal development stages. Although, a greater proportion of mature male than female was detected during the study, the sex ratio showed that the overall number of female was higher than male. The ovaries had multiple oocyte size classes at every stage of gonadal development, thus R. tawarensis can be classified as a group synchronous spawner or a fractional multiple spawner. Conclusion The spawning seasons of R. tawarensis were three times a year and September being the peak of the reproductive season and the female was the predominant sex. This species is classified as a group synchronous spawner. PMID:20482777

  7. Spawning habitat unsuitability: an impediment to cisco rehabilitation in Lake Michigan?

    USGS Publications Warehouse

    Madenjian, Charles P.; Rutherford, Edward S.; Blouin, Marc A.; Sederberg, Bryan J.; Elliott, Jeff R.

    2011-01-01

    The cisco Coregonus artedi was one of the most important native prey fishes in Lake Michigan and in the other four Laurentian Great Lakes. Most of the cisco spawning in Lake Michigan was believed to have occurred in Green Bay. The cisco population in Lake Michigan collapsed during the 1950s, and the collapse was attributed in part to habitat degradation within Green Bay. Winter water quality surveys of lower Green Bay during t