Structure-activity relationship of crustacean peptide hormones.

PubMed

Katayama, Hidekazu

2016-01-01

In crustaceans, various physiological events, such as molting, vitellogenesis, and sex differentiation, are regulated by peptide hormones. To understanding the functional sites of these hormones, many structure-activity relationship (SAR) studies have been published. In this review, the author focuses the SAR of crustacean hyperglycemic hormone-family peptides and androgenic gland hormone and describes the detailed results of our and other research groups. The future perspectives will be also discussed.

Ecdysone receptor agonism leading to lethal molting ...

EPA Pesticide Factsheets

Molting is a key biological process in growth, development, reproduction and survival in arthropods. Complex neuroendocrine pathways are involved in the regulation of molting and may potentially become targets of environmental endocrine disrupting compounds (EDCs). For example, several classes of pesticides used in agriculture and aquaculture specifically target key endocrine regulators of the molting process. These chemicals may also pose hazards to non-target species by causing molting defects, thus affecting the health of the ecosystems. The present review summarized the available knowledge on molting-related endocrine regulation and disruption in arthropods (with special focus on insects and crustaceans), in order to identify research gaps and develop a toxicity mechanism-based model for environmental hazard and risk assessment. Based on the review, multiple targets in the molting processes that EDCs can interact with were characterized to inform future studies. An adverse outcome pathway (AOP) describing ecdysone receptor agonism leading to incomplete ecdysis associated mortality was developed according to the OECD guideline and evaluated for weight of evidence using the Evolved Bradford Hill Criteria. This review proposed the first invertebrate endocrine disruption AOP and may serve as a knowledge foundation for future environmental studies and AOP development. Development of high throughput toxicology (HTT) programs (e.g., ToxCast, Tox21) and potential a

Structure and function of matrix proteins and peptides in the biomineral formation in crustaceans.

PubMed

Nagasawa, Hiromichi

2011-01-01

Crustaceans have hard cuticle with layered structure, which is composed mainly of chitin, proteins, and calcium carbonate. Crustaceans grow by shedding the old cuticle and replacing it with a new one. Decalcification in the cuticle during the pre-molt stage and concomitant calcification in the stomach to form gastroliths observed in some crustacean species are triggered by the molting hormone. Various proteins and peptides have been identified from calcified cuticle and gastroliths, and their functions have been examined in terms of calcification and interaction with chitin. Acidic nature of matrix proteins is important for recruitment of calcium ions and interaction with calcium carbonate. Examination of the relationship between amino acid sequence containing acidic amino acid residues and calcification inhibitory activity revealed that the potency did not depend on the sequence but on the number of acidic amino acid residues. Calcium carbonate in the calcified tissues of crustaceans is amorphous in many cases. Crustaceans take a strategy to induce and maintain amorphous calcium carbonate by using low-molecular-weight phosphorus compounds.

Proteomic analysis of Bombyx mori molting fluid: Insights into the molting process.

PubMed

Liu, Hua-Wei; Wang, Luo-Ling; Tang, Xin; Dong, Zhao-Ming; Guo, Peng-Chao; Zhao, Dong-Chao; Xia, Qing-You; Zhao, Ping

2018-02-20

Molting is an essential biological process occurring multiple times throughout the life cycle of most Ecdysozoa. Molting fluids accumulate and function in the exuvial space during the molting process. In this study, we used liquid chromatography-tandem mass spectrometry to investigate the molting fluids to analyze the molecular mechanisms of molting in the silkworm, Bombyx mori. In total, 375 proteins were identified in molting fluids from the silkworm at 14-16h before pupation and eclosion, including 12 chitin metabolism-related enzymes, 35 serine proteases, 15 peptidases, and 38 protease inhibitors. Gene ontology analysis indicated that "catalytic" constitutes the most enriched function in the molting fluid. Gene expression patterns and bioinformatic analyses suggested that numerous enzymes are involved in the degradation of cuticle proteins and chitin. Protein-protein interaction network and activity analyses showed that protease inhibitors are involved in the regulation of multiple pathways in molting fluid. Additionally, many immune-related proteins may be involved in the immune defense during molting. These results provide a comprehensive proteomic insight into proteolytic enzymes and protease inhibitors in molting fluid, and will likely improve the current understanding of physiological processes in insect molting. Insect molting constitutes a dynamic physiological process. To better understand this process, we used LC-MS/MS to investigate the proteome of silkworm molting fluids and identified key proteins involved in silkworm molting. The biological processes of the old cuticle degradation pathway and immune defense response were analyzed in the proteome of silkworm molting fluid. We report that protease inhibitors serve as key factors in the regulation of the molting process. The proteomic results provide new insight into biological molting processes in insects. Copyright © 2017 Elsevier B.V. All rights reserved.

Limb regeneration and molting processes under chronic methoprene exposure in the mud fiddler crab, Uca pugnax.

PubMed

Stueckle, Todd A; Likens, Jason; Foran, Christy M

2008-04-01

Insect growth regulator application for wetland mosquito control remains controversial due to the potential for disruption of normal development and growth processes in non-target crustaceans and beneficial arthropods, e.g. Apis mellifera. Concerns include slow-release methoprene formulations and its environmental breakdown products which mimic an endogenous crustacean hormone and retinoids, respectively. Our primary objective was to evaluate the effect that a chronic methoprene exposure would have on male and female Uca pugnax limb regeneration and molting. After single limb autonomy, limb growth and molt stage were monitored every two days while eyestalk ablation was used to induce proecdysis. Dorsal carapace was collected 6 days post-molt to determine protein and chitin content. In post-molt crabs, methoprene-exposed individuals displayed lower percent gain in body weight. Male crabs lost more weight per body volume than females, took significantly longer to proceed through proecdysis than females exposed to 0.1 microg/L methoprene and exhibited significantly elevated frequency for abnormal limb formation at 1.0 microg/L while females displayed no such trend. Methoprene did not significantly alter extractable exoskeleton protein or chitin content. However, variable water-soluble protein expression increased with exposure at 1.0 microg/L (1 ppb) which contributed to overall variability in total protein content. Our findings suggest that adult male U. pugnax possess greater sensitivity to chronic methoprene exposure during limb regeneration and molting, potentially affecting their post-molt fitness. Furthermore, methoprene has the potential to impact post-molt biomass and exocuticle quality.

Control of molting in crustacea

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

Skinner, D.M.; Graham, D.E.; Holland, C.A.

1982-01-01

The single, overriding event that occurs during all proecdysial periods in crustaceans is the synthesis of a new exoskeleton that encompasses an enlarged animal when the old shell is cast off. Regeneration of missing appendages and larval or puberty metamorphoses also occur during proecdysis. Proecdysial periods have been divided into substages defined by the occurrence of specific events. Although a number of factors must be postulated to account for individual proecdysial events, only the molting hormone, 20-hydroxyecdysone, has been identified and isolated. Much evidence indicates that the X-organ sinus glands complex, a neurosecretory tissue located in the eyestalks, is themore » source of a molt inhibiting hormone (MIH) responsible for maintaining animals in anecdysis. An exuviation factor has been proposed to support the extrication of the animal from the old exoskeleton. There is evidence for a limb growth inhibitory factor (LGIF) that affects the rate of growth of regenerating limbs. We are proposing an anecdysial limb autotomy factor (LAF/sub an/) that propels into precocious molts anecdysial limb autotomy factor (LAF/sub pro/) that interrupts the proecdysial period of animals that lose one or more normal or partially regenerated pereopods before a critical time in proecdysis.« less

Molt-related susceptibility and regenerative limb growth as sensitive indicators of aquatic pollutant toxicity to crustaceans

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

Rao, K.R.; Conklin, P.J.

1986-01-01

The study evaluated the comparative toxicity of various pollutants to intermolt and molting grass shrimp (Palaemonetes pugio). Most of the tested materials (pentachlorophenol, tetrachlorophenols, trichlorophenols, methylenebis dichlorophenol, dibutyl phthalate, chromium, and drilling mud) were more toxic to molting shrimp than to intermolt shrimp. Radio-tracer studies with 2,4,5-trichlorophenol and pentachlorophenol indicated that the increased susceptibility of newly molted shrimp is linked to increased pollutant uptake.

What do we (need to) know about the melatonin in crustaceans?

PubMed

Sainath, S B; Swetha, Ch; Reddy, P Sreenivasula

2013-08-01

Melatonin (N-acetyl-5-methoxy-tryptamine) was first discovered from the bovine pineal gland extract in 1958. Since then, its synthesis, metabolism, physiological, and patho-physiological functions are well studied in vertebrates; there is an increasing recognition of melatonin in invertebrates and especially in crustaceans. The presence of melatonin in crustaceans is now well documented and some functional aspects in the framework of crustacean biology have been demonstrated. This review aims at giving a comprehensive overview of the various physiological events regulated by this pleiotropic hormone. Topics include: glucose homeostasis, regulation of reproduction, molting, limb regeneration, and antioxidant properties. Finally, perspectives on current and possible research are offered. Copyright © 2013 Wiley Periodicals, Inc.

What Kills the Hindgut Flagellates of Lower Termites during the Host Molting Cycle?

PubMed Central

Nalepa, Christine A.

2017-01-01

Subsocial wood feeding cockroaches in the genus Cryptocercus, the sister group of termites, retain their symbiotic gut flagellates during the host molting cycle, but in lower termites, closely related flagellates die prior to host ecdysis. Although the prevalent view is that termite flagellates die because of conditions of starvation and desiccation in the gut during the host molting cycle, the work of L.R. Cleveland in the 1930s through the 1960s provides a strong alternate hypothesis: it was the changed hormonal environment associated with the origin of eusociality and its concomitant shift in termite developmental ontogeny that instigates the death of the flagellates in termites. Although the research on termite gut microbial communities has exploded since the advent of modern molecular techniques, the role of the host hormonal environment on the life cycle of its gut flagellates has been neglected. Here Cleveland’s studies are revisited to provide a basis for re-examination of the problem, and the results framed in the context of two alternate hypotheses: the flagellate symbionts are victims of the change in host social status, or the flagellates have become incorporated into the life cycle of the eusocial termite colony. Recent work on parasitic protists suggests clear paths for exploring these hypotheses and for resolving long standing issues regarding sexual-encystment cycles in flagellates of the Cryptocercus-termite lineage using molecular methodologies, bringing the problem into the modern era. PMID:29258251

Primary molt of California condors

USGS Publications Warehouse

Snyder, N.F.R.; Johnson, E.V.; Clendenen, D.A.

1987-01-01

Primary molt of the California Condor (Gymnogyps californianus) was studied intensively from 1982 through 1985, using repeated flight photographs of the remaining individuals in the wild population as a basis for most analyses. On the average, wild condors replaced 4.4 of the 8 emarginated primaries on each wing each year. The sepcific primaries molted were generally the ones missed in the previous year and were usually well-distributed among the eight possibilities, with a tendency for low-numbered primaries to molt earlier than high-numbered primaries. Within individuals, molt of one wing was commonly very different from that of the other wing. Primarily molt of captive juveniles was similar to that of wild juveniles. The interval from loss to full replacement of individual primary feathers was normally 3 1/2 to 4 months, with the primaries closest to the leading edge of the wing growing most slowly. Most primarities were shed between 1 February and 1 September. Primaries lost in late fall and early winter were not replaced until the following summer, indicating interrupted molt over the winter. In general, primary molt of the condor differs from that of smaller cathartids in being highly seasonal, highly variable in sequence, highly asymmetric between wings, and in following a roughly 2-year cycle. Molt of the condor shows many similarities to that of the White Stork (Ciconia ciconia) and to that of large accipitrid vultures.

Using molt cycles to categorize the age of tropical birds: an integrative new system

Treesearch

Jared D. Wolfe; Thomas B. Ryder; Peter Pyle

2010-01-01

Accurately differentiating age classes is essential for the long-term monitoring of resident New World tropical bird species. Molt and plumage criteria have long been used to accurately age temperate birds, but application of temperate age-classification models to the Neotropics has been hindered because annual life-cycle events of tropical birds do not always...

Crustaceans as a model for microgravity-induced muscle atrophy

NASA Astrophysics Data System (ADS)

Mykles, D. L.

Atrophy of skeletal muscles is a serious problem in a microgravity environment. It is hypothesized that the unloading of postural muscles, which no longer must resist gravity force, causes an accelerated breakdown of contractile proteins, resulting in a reduction in muscle mass and strength. A crustacean model using the land crab, Gecarcinus lateralis, to assess the effects of spaceflight on protein metabolism is presented. The model is compared to a developmentally-regulated atrophy in which a premolt reduction in muscle mass allows the withdrawal of the large claws at molt. The biochemical mechanisms underlying protein breakdown involves both Ca^2+-dependent and multicatalytic proteolytic enzymes. Crustacean claw muscle can be used to determine the interactions between shortening and unloading at the molecular level.

Crustaceans as a model for microgravity-induced muscle atrophy

NASA Technical Reports Server (NTRS)

Mykles, D. L.

1996-01-01

Atrophy of skeletal muscles is a serious problem in a microgravity environment. It is hypothesized that the unloading of postural muscles, which no longer must resist gravity force, causes an accelerated breakdown of contractile proteins, resulting in reduction in muscle mass and strength. A crustacean model using the land crab, Gecarcinus lateralis, to assess the effects of spaceflight on protein meatabolism is presented. The model is compared to a developmentally-regulated atrophy in which a premolt reduction in muscle mass allows the withdrawal of the large claws at molt. The biochemical mechanisms underlying protein breakdown involves both Ca2(+) -dependent and multicatalytic proteolytic enzymes. Crustacean claw muscle can be used to determine the interactions between shortening and unloading at the molecular level.

Calcium homeostasis in crustacea: the evolving role of branchial, renal, digestive and hypodermal epithelia.

PubMed

Wheatly, M G

1999-06-01

Crustaceans serve as an ideal model for the study of calcium homeostasis due to their natural molting cycle. Demineralization and remineralization of the calcified cuticle is accompanied by bidirectional Ca transfer across the primary Ca transporting epithelia: gills, antennal gland (kidney), digestive system, and cuticular hypodermis. The review will demonstrate how a continuum of crustaceans can be used as a paradigm for the evolution of Ca transport mechanisms. Generally speaking, aquatic crustaceans rely primarily on branchial Ca uptake and accordingly are affected by water Ca content; terrestrial crustaceans rely on intake of dietary Ca across the digestive epithelium. Synchrony of mineralization at the cuticle vs. storage sites will be presented Physiological and behavioral adaptations have evolved to optimize Ca balance during the molting cycle in different Ca environments. Intracellular Ca regulation reveals common mechanisms of apical and basolateral membrane transport as well as intracellular sequestration. Regulation of cell Ca concentration will be discussed in intermolt and during periods of the molting cycle when transepithelial Ca flux is significantly elevated. Molecular characterization of the sarco-/endoplasmic reticular Ca pump in aquatic species reveals the presence of two isoforms that originate from a single gene. This gene is differentially expressed during the molting cycle. Gene expression may be regulated by a suite of hormones including ecdysone, calcitonin, and vitamin D. Perspectives for future research are presented.

Survival of surf scoters and white-winged scoters during remigial molt

USGS Publications Warehouse

Uher-Koch, Brian D.; Esler, Daniel N.; Dickson, Rian D.; Hupp, Jerry W.; Evenson, Joseph R.; Anderson, Eric M.; Barrett, Jennifer; Schmutz, Joel A.

2014-01-01

Quantifying sources and timing of variation in demographic rates is necessary to determine where and when constraints may exist within the annual cycle of organisms. Surf scoters (Melanitta perspicillata) and white-winged scoters (M. fusca) undergo simultaneous remigial molt during which they are flightless for >1 month. Molt could result in reduced survival due to increased predation risk or increased energetic demands associated with regrowing flight feathers. Waterfowl survival during remigial molt varies across species, and has rarely been assessed for sea ducks. To quantify survival during remigial molt, we deployed very high frequency (VHF) transmitters on surf scoters (n = 108) and white-winged scoters (n = 57) in southeast Alaska and the Salish Sea (British Columbia and Washington) in 2008 and 2009. After censoring mortalities potentially related to capture and handling effects, we detected no mortalities during remigial molt; thus, estimates of daily and period survival for both scoter species during molt were 1.00. We performed sensitivity analyses in which mortalities were added to the dataset to simulate potential mortality rates for the population and then estimated the probability of obtaining a dataset with 0 mortalities. We found that only at high survival rates was there a high probability of observing 0 mortalities. We conclude that remigial molt is normally a period of low mortality in the annual cycle of scoters. The molt period does not appear to be a constraint on scoter populations; therefore, other annual cycle stages should be targeted by research and management efforts to change population trajectories.

Glycolytic intermediates induce amorphous calcium carbonate formation in crustaceans.

PubMed

Sato, Ai; Nagasaka, Seiji; Furihata, Kazuo; Nagata, Shinji; Arai, Isao; Saruwatari, Kazuko; Kogure, Toshihiro; Sakuda, Shohei; Nagasawa, Hiromichi

2011-04-01

It has been thought that phosphorus in biominerals made of amorphous calcium carbonate (ACC) might be related to ACC formation, but no such phosphorus-containing compounds have ever been identified. Crustaceans use ACC biominerals in exoskeleton and gastroliths so that they will have easy access to calcium carbonate inside the body before and after molting. We have identified phosphoenolpyruvate and 3-phosphoglycerate, intermediates of the glycolytic pathway, in exoskeleton and gastroliths and found them important for stabilizing ACC.

Crustacean molt-inhibiting hormone: structure, function, and cellular mode of action.

PubMed

Nakatsuji, Teruaki; Lee, Chi-Ying; Watson, R Douglas

2009-02-01

In Crustacea, secretion of ecdysteroid molting hormones by Y-organs is regulated, at least in part, by molt-inhibiting hormone (MIH), a polypeptide neurohormone produced by neurosecretory cells of the eyestalks. This article reviews current knowledge of MIH, with particular emphasis on recent findings regarding the (a) structure of the MIH peptide and gene, (b) levels of MIH in eyestalks and hemolymph, (c) cellular mechanism of action of MIH, and (d) responsiveness of Y-organs to MIH. At least 26 MIH/MIH-like sequences have been directly determined by protein sequencing or deduced from cloned cDNA. Recent studies reveal the existence of multiple forms of MIH/MIH-like molecules among penaeids and raise the possibility that molecular polymorphism may exist more generally among MIH (type II) peptides. The hemolymphatic MIH titer has been determined for two species, a crayfish (Procambarus clarkii) and a crab (Carcinus maenas). The data are dissimilar and additional studies are needed. Composite data indicate cellular signaling pathways involving cGMP, cAMP, or both may play a role in MIH-induced suppression of ecdysteroidogenesis. Data from the two species studied in our laboratories (P. clarkii and Callinectes sapidus) strongly favor cGMP as the physiologically relevant second messenger. Ligand-binding studies show an MIH receptor exists in Y-organ plasma membranes, but the MIH receptor has not been isolated or fully characterized for any species. Such studies are critical to understanding the cellular mechanism by which MIH regulates ecdysteroidogenesis. Rates of ecdysteroid synthesis appear also to be influenced by stage-specific changes in the responsiveness of Y-organs to MIH. The changes in responsiveness result, at least in part, from changes in glandular phosphodiesterase (PDE) activity. The PDE isotype (PDE1) present in Y-organs of C. sapidus is calcium/calmodulin dependent. Thus, calcium may regulate ecdysteroidogenesis through activation of glandular PDE.

Respiratory and Metabolic Impacts of Crustacean Immunity: Are there Implications for the Insects?

PubMed

Burnett, Karen G; Burnett, Louis E

2015-11-01

Extensive similarities in the molecular architecture of the crustacean immune system to that of insects give credence to the current view that the Hexapoda, including Insecta, arose within the clade Pancrustacea. The crustacean immune system is mediated largely by hemocytes, relying on suites of pattern recognition receptors, effector functions, and signaling pathways that parallel those of insects. In crustaceans, as in insects, the cardiovascular system facilitates movement of hemocytes and delivery of soluble immune factors, thereby supporting immune surveillance and defense along with other physiological functions such as transport of nutrients, wastes, and hormones. Crustaceans also rely heavily on their cardiovascular systems to mediate gas exchange; insects are less reliant on internal circulation for this function. Among the largest crustaceans, the decapods have developed a condensed heart and a highly arteriolized cardiovascular system that supports the metabolic demands of their often large body size. However, recent studies indicate that mounting an immune response can impair gas exchange and metabolism in their highly developed vascular system. When circulating hemocytes detect the presence of potential pathogens, they aggregate rapidly with each other and with the pathogen. These growing aggregates can become trapped in the microvasculature of the gill where they are melanized and may be eliminated at the next molt. Prior to molting, trapped aggregates of hemocytes also can impair hemolymph flow and oxygenation at the gill. Small shifts to anaerobic metabolism only partially compensate for this decrease in oxygen uptake. The resulting metabolic depression is likely to impact other energy-expensive cellular processes and whole-animal performance. For crustaceans that often live in microbially-rich, but oxygen-poor aquatic environments, there appear to be distinct tradeoffs, based on the gill's multiple roles in respiration and immunity. Insects have

Dynamics of vitellogenin and vitellogenesis-inhibiting hormone levels in adult and subadult whiteleg shrimp, Litopenaeus vannamei: relation to molting and eyestalk ablation.

PubMed

Kang, Bong Jung; Okutsu, Tomoyuki; Tsutsui, Naoaki; Shinji, Junpei; Bae, Sun-Hye; Wilder, Marcy N

2014-01-01

Levels of vitellogenin (VG) and vitellogenesis-inhibiting hormone (VIH) in the whiteleg shrimp, Litopenaeus vannamei, were measured by time-resolved fluoroimmunoassay in relation to the molting cycle and ovarian maturation induced by eyestalk ablation. During the molt cycle, VG mRNA expression levels and VG concentrations showed similar patterns of fluctuation. VG levels increased significantly at early intermolt (stage C0) in adults, but not in subadults. Unilateral and bilateral eyestalk ablation increased VG levels in adults, whereas only bilateral eyestalk ablation affected subadults. VIH levels showed contrasting patterns between adults and subadults. In adults, levels were high in late postmolt adults (stage B) and then low thereafter, whereas they increased from postmolt (stage A) to intermolt (stage C0) in subadults and remained high. Unilateral eyestalk ablation increased VIH levels 10 days following ablation in adults, after which levels decreased at 20 days. VIH levels decreased from 10 to 20 days after bilateral ablation. Both unilateral and bilateral ablation led to increased VIH levels in subadults. Eyestalk ablation induced ovarian maturation, but did not reduce VIH concentrations in the hemolymph. This phenomenon was perhaps due to other crustacean hyperglycemic hormone peptides having cross-reactivity with VIH antibodies. This is the first report to quantify concentrations of VG and VIH together in L. vannamei hemolymph, and to examine their relative dynamics.

Whole Transcriptome Analysis Provides Insights into Molecular Mechanisms for Molting in Litopenaeus vannamei

PubMed Central

Gao, Yi; Zhang, Xiaojun; Wei, Jiankai; Sun, Xiaoqing; Yuan, Jianbo; Li, Fuhua; Xiang, Jianhai

2015-01-01

Molting is one of the most important biological processes in shrimp growth and development. All shrimp undergo cyclic molting periodically to shed and replace their exoskeletons. This process is essential for growth, metamorphosis, and reproduction in shrimp. However, the molecular mechanisms underlying shrimp molting remain poorly understood. In this study, we investigated global expression changes in the transcriptomes of the Pacific white shrimp, Litopenaeus vannamei, the most commonly cultured shrimp species worldwide. The transcriptome of whole L. vannamei was investigated by RNA-sequencing (RNA-seq) throughout the molting cycle, including the inter-molt (C), pre-molt (D0, D1, D2, D3, D4), and post-molt (P1 and P2) stages, and 93,756 unigenes were identified. Among these genes, we identified 5,117 genes differentially expressed (log2ratio ≥1 and FDR ≤0.001) in adjacent molt stages. The results were compared against the National Center for Biotechnology Information (NCBI) non-redundant protein/nucleotide sequence database, Swiss-Prot, PFAM database, the Gene Ontology database, and the Kyoto Encyclopedia of Genes and Genomes database in order to annotate gene descriptions, associate them with gene ontology terms, and assign them to pathways. The expression patterns for genes involved in several molecular events critical for molting, such as hormone regulation, triggering events, implementation phases, skelemin, immune responses were characterized and considered as mechanisms underlying molting in L. vannamei. Comparisons with transcriptomic analyses in other arthropods were also performed. The characterization of major transcriptional changes in genes involved in the molting cycle provides candidates for future investigation of the molecular mechanisms. The data generated in this study will serve as an important transcriptomic resource for the shrimp research community to facilitate gene and genome annotation and to characterize key molecular processes

Chapter 9: Molts and Plumages in the Annual Cycle of the Marbled Murrelet

Treesearch

Harry R. Carter; Janet L. Stein

1995-01-01

Marbled Murrelets have distinct basic, alternate and juvenal plumages. In after-hatching-year (adult) birds, the incomplete pre-alternate molt occurs rapidly over a period of about one month per individual between late February and mid-May. The complete pre-basic molt occurs between mid-July and December. At this time, individuals are flightless for about two months....

Crustacean hyperglycemic hormone (CHH) neuropeptidesfamily: Functions, titer, and binding to target tissues.

PubMed

Chung, J Sook; Zmora, N; Katayama, H; Tsutsui, N

2010-05-01

The removal of the eyestalk (s) induces molting and reproduction promoted the presence of regulatory substances in the eyestalk (ES), particularly medulla terminalis X-organ and the sinus gland (MTXO-SG). The PCR-based cloning strategies have allowed for isolating a great number of cDNAs sequences of crustacean hyperglycemic hormone (CHH) neuropeptides family from the eyestalk and non-eyestalk tissues, e.g., pericardial organs and fore- and hindguts. However, the translated corresponding neuropeptides in these tissues, their circulating concentrations, the mode of actions, and specific physiological functions have not been well described. The profiles of CHH neuropeptides present in the MTXO-SG may differ among decapod crustacean species, but they can be largely divided into two sub-groups on the basis of structural homology: (1) CHH and (2) molt-inhibiting hormone (MIH)/mandibular organ-inhibiting hormone (MOIH)/vitellogenesis/gonad-inhibiting hormone (V/GIH). CHH typically elevating the level of circulating glucose from animals under stressful conditions (hyper- and hypothermia, hypoxia, and low salinity) has multiple target tissues and functions such as ecdysteroidogenesis, osmoregulation, and vitellogenesis. Recently, MIH, known for exclusively suppressing ecdysteroidogenesis in Y-organs, is also reported to have an additional role in vitellogenesis of adult female crustacean species, suggesting that some CHH neuropeptides may acquire an extra regulatory role in reproduction at adult stage. This paper reviews the regulatory roles of CHH and MIH at the levels of specific functions, temporal and spatial expression, titers, their binding sites on the target tissues, and second messengers from two crab species: the blue crab, Callinectes sapidus, and the European green crab, Carcinus maenas. It further discusses the diverse regulatory roles of these neuropeptides and the functional plasticity of these neuropeptides in regard to life stage and species

When the seasons don't fit: speedy molt as a routine carry-over cost of reproduction.

PubMed

Dietz, Maurine W; Rogers, Ken G; Piersma, Theunis

2013-01-01

The failure of animals to fit all life-cycle stages into an annual cycle could reduce the chances of successful breeding. In some cases, non-optimal strategies will be adopted in order to maintain the life-cycle within the scope of one year. We studied trade-offs made by a High Arctic migrant shorebird, the red knot Calidris canutus islandica, between reproduction and wing feather molt carried out in the non-breeding period in the Dutch Wadden Sea. We compared primary molt duration between birds undertaking the full migratory and breeding schedule with birds that forego breeding because they are young or are maintained in captivity. Molt duration was ca. 71 days in breeding adults, which was achieved by an accelerated feather replacement strategy. Second-year birds and captive adults took ca. 22% and 27% longer, respectively. Second-year birds start molt in late June, more than four weeks before captive adults, and almost seven weeks before adults that return from breeding in late July-August. Adults finish molt in October when steeply increasing thermostatic costs and reductions in food availability occur. Primary molt duration was longer in female than in male knots (all ages), which was accordance with the somewhat larger body size of females. Since fast growth leads to lower quality feathers, the speedy wing molt shown by Arctic-breeding birds may represent a time constraint that is an unavoidable and routine cost of reproduction. So far it was hypothesized that only birds over 1 kg would have difficulty fitting molt within a year. Here we show that in birds an order of magnitude smaller, temporal imperatives may impose the adoption of non-optimal life-cycle routines in the entire actively breeding population.

Ontogeny of decapod crustacean hemocyanin: effects of temperature and nutrition.

PubMed

Terwilliger, N; Dumler, K

2001-03-01

Hemocyanin is present throughout the decapod crustacean's life, usually as one-hexamer and two-hexamer oligomers. Hemocyanins of some decapod crustaceans undergo changes in subunit composition and oxygen affinity during development. Maternal hemocyanin is taken up from the hemolymph via endocytosis by the oocyte. Embryo hemocyanin differs in subunit composition from hemocyanin of oocyte and adult crab and may represent the onset of hemocyanin synthesis. Complex changes in expression of hemocyanin subunits occur through megalopa and early juvenile stages of the crab Cancer magister, culminating in the pattern of adult hemocyanin. The influences of food availability and temperature on development, growth and hemocyanin ontogeny in early juvenile C. magister have been studied. Crabs were raised in warm or cold sea water and fed high or low levels of food for 6 months. While intermolt period was shorter in crabs fed high food levels, especially those raised in warm water, crabs reared in cold water with high food levels attained the largest sizes. Thus increased food availability affects growth more than increased temperature. Adult hemocyanin appeared at about the same number of weeks after the start of the experiment for crabs in the warm water/high food, warm water/low food and cold water/high food groups, even though warm water/low food crabs had molted fewer times. Crabs in the cold water/low food group expressed adult hemocyanin much later than the other groups. Molt stage and maturation from juvenile to adult are not absolutely coupled, and food availability has a greater influence than temperature on hemocyanin ontogeny.

Lunar-Rhythmic Molting in Laboratory Populations of the Noble Crayfish Astacus astacus (Crustacea, Astacidea): An Experimental Analysis

PubMed Central

Franke, Robert; Hoerstgen-Schwark, Gabriele

2013-01-01

Juvenile noble crayfish, Astacusastacus (Crustacea, Astacidea) in the second year of age were kept in the laboratory for a twelve-month period under continuing “summer conditions” (LD 16:8, 19°C). Molting processes in this population could be synchronized by artificial moonlight cycles. Peaks of exuviations occurred at “new moons”. Males showed a slightly higher degree of synchronization than females. A phase-shift of the artificial lunar cycle in relation to the natural cycle resulted in a corresponding shift of the molting cycle. This clearly demonstrates that changes in the nocturnal light regime provide the primary external information for the lunar-monthly molting rhythm. There is a first indication that lunar photic stimuli do not act directly but as a zeitgeber which entrains an endogenous molting rhythm to the lunar cycle. Moreover, the results of the long-term experiments suggest that the hibernal resting period of A . astacus in the field (no molts between October and April) may also involve some endogenous programming. Continuing artificial summer conditions can delay but not completely suppress this resting period. The adaptive significance of the phenomena and how the findings may be applied to improve the management of crowded crayfish stocks are discussed. PMID:23840899

Elevated expression of neuropeptide signaling genes in the eyestalk ganglia and Y-organ of Gecarcinus lateralis individuals that are refractory to molt induction.

PubMed

Pitts, Natalie L; Schulz, Hanna M; Oatman, Stephanie R; Mykles, Donald L

2017-12-01

Molting is induced in decapod crustaceans via multiple leg autotomy (MLA) or eyestalk ablation (ESA). MLA removes five or more walking legs, which are regenerated and become functional appendages at ecdysis. ESA eliminates the primary source of molt-inhibiting hormone (MIH) and crustacean hyperglycemic hormone (CHH), which suppress the production of molting hormones (ecdysteroids) from the molting gland or Y-organ (YO). Both MLA and ESA are effective methods for molt induction in Gecarcinus lateralis. However, some G. lateralis individuals are refractory to MLA, as they fail to complete ecdysis by 12weeks post-MLA; these animals are in the "blocked" condition. Quantitative polymerase chain reaction was used to quantify mRNA levels of neuropeptide and mechanistic target of rapamycin (mTOR) signaling genes in YO, eyestalk ganglia (ESG), thoracic ganglion (TG), and brain of intact and blocked animals. Six of the seven neuropeptide signaling genes, three of four mTOR signaling genes, and Gl-elongation factor 2 (EF2) mRNA levels were significantly higher in the ESG of blocked animals. Gl-MIH and Gl-CHH mRNA levels were higher in the TG and brain of blocked animals and levels increased in both control and blocked animals in response to ESA. By contrast, mRNA levels of Gl-EF2 and five of the 10 MIH signaling pathway genes in the YO were two to four orders of magnitude higher in blocked animals compared to controls. These data suggest that increased MIH and CHH synthesis in the ESG contributes to the prevention of molt induction by MLA in blocked animals. The up-regulation of MIH signaling genes in the YO of blocked animals suggests that the YO is more sensitive to MIH produced in the ESG, as well as MIH produced in brain and TG of ESA animals. Both the up-regulation of MIH signaling genes in the YO and of Gl-MIH and Gl-CHH in the ESG, TG, and brain appear to contribute to some G. lateralis individuals being refractory to MLA and ESA. Copyright © 2017 Elsevier Inc. All

Breeding seasons, molt patterns, and gender and age criteria for selected northeastern Costa Rican resident landbirds

Treesearch

Jared D. Wolfe; Peter Pyle; C. John Ralph

2009-01-01

Detailed accounts of molt and breeding cycles remain elusive for the majority of resident tropical bird species. We used data derived from a museum review and 12 years of banding data to infer breeding seasonality, molt patterns, and age and gender criteria for 27 common landbird species in northeastern Costa Rica. Prealternate molts appear to be rare, only occurring...

Effects of periodical salinity fluctuation on the growth, molting, energy homeostasis and molting-related gene expression of Litopenaeus vannamei

NASA Astrophysics Data System (ADS)

Zhang, Dan; Guo, Xiantao; Wang, Fang; Dong, Shuanglin

2016-10-01

To determine the response of Litopenaeus vannamei to periodical salinity fluctuation, a 30-day experiment was conducted in laboratory. In this experiment, two salinity fluctuation amplitudes of 4 (group S4) and 10 (group S10) were designed. The constant salinity of 30 (group S0) was used as the control. Levels of shrimp growth, molting frequency (MF), cellular energy status (ATP, ADP and AMP), as well as the expression of genes encoding molt-inhibiting hormone (MIH), crustacean hyperglycemic hormone (CHH), ecdysteroid-regulated protein (ERP), and energy-related AMP-activated protein kinase (AMPK) were determined. The results showed that periodical salinity fluctuation significantly influenced all indicators except MF which ranged from 13.3% in group S10 to15.4% in group S4. In comparison with shrimps cultured at the constant salinity of 30, those in group S4 showed a significant elevation in growth rate, food conversion efficiency, cellular energy status, ERP and MIH gene transcript abundance, and a significant reduction in CHH and AMPK transcript abundance ( P < 0.05). However, salinity fluctuation of 10 only resulted in a significant variation in MIH and CHH gene expression when compared to the control ( P < 0.05). According to our findings, L. vannamei may be highly capable of tolerating salinity fluctuation. When ambient salinity fluctuated at approx. 4, the increased MF and energy stores in organisms may aid to promoting shrimp growth.

Effects of chlordecone on 20-hydroxyecdysone concentration and chitobiase activity in a decapod crustacean, Macrobrachium rosenbergii.

PubMed

Lafontaine, Anne; Gismondi, Eric; Boulangé-Lecomte, Céline; Geraudie, Perrine; Dodet, Nathalie; Caupos, Fanny; Lemoine, Soazig; Lagadic, Laurent; Thomé, Jean-Pierre; Forget-Leray, Joëlle

2016-07-01

Chlordecone (CLD) is an organochlorine insecticide abundant in aquatic environment of the French West Indies. However, few studies have investigated its impact on freshwater invertebrates. Whereas CLD is suspected of inducing endocrine disruption, this work aimed to study the effects of environmentally relevant concentrations of CLD on the 20-hydroxyecdysone (20-HE) hormone concentration and on the chitobiase activity, both having key roles in the molting process of crustaceans. In addition, the bioaccumulation of CLD was measured in the muscle tissue of Macrobrachium rosenbergii to underline potential dose-response relationship. The results have shown that CLD was bioaccumulated in exposed organisms according to a trend to a dose-response relationship. Moreover, it was observed that CLD decreased the 20-HE concentration in exposed prawns when compared to control, whatever the duration of exposure, as well as it inhibited the chitobiase activity after 30days of exposure. The present study indicates that CLD could interfere with molting process of M. rosenbergii by disturbing the 20-HE concentration and the activity of chitobiase, suggesting consequences at the long term on the shrimp development. This study also confirmed that CLD could be an endocrine disruptor in decapod crustaceans, as it was already observed in vertebrates. Copyright © 2016 Elsevier B.V. All rights reserved.

Prealternate molt in nuthatches

USGS Publications Warehouse

Banks, Richard C.

1978-01-01

Nuthatches of the genus Sitta constitute one of the passerine groups in which prealternate (prenuptial) molt is generally believed not to occur. Dwight (1900: 298) discussed this genus with the family Paridae and stated: "All the members of this family have only the annual moult. They are peculiar in assuming a juvenal plumage closely resembling the pale nuptial plumage which results from extreme fading of the winter dress." Witherby (in Witherby et al. 1938: 244) remarked that in S. europaea the summer plumage is attained by abrasion rather than by molt. Following Dwight's analysis, Bent (1948) recorded that the prenuptial molt did not occur in S. carolinensis or S. canadensis. Although Norris (1958: 246) found several females of S. pygmaea that were replacing feathers in the nuchal region in March and April, he regarded this as a regrowth of feathers lost in social interactions rather than as prealternate molt; the replacement of contour feathers "over nearly every part of the body" in early April by one female of that species was considered to be "an aberrant instance of prenuptial molt." Norris (op. cit.) stated categorically that "There is no prenuptial molt in Sitta pusilla." For most species in the genus, however, I have been unable to find any statement, even a negative one, concerning the occurrence of this molt. On the other hand, there is a partial prealternate molt in the seasonally dimorphic Tichodroma muraria, usually considered a member of the family Sittidae but in a different subfamily.

Control of molt in birds: association with prolactin and gonadal regression in starlings.

PubMed

Dawson, Alistair

2006-07-01

Despite the importance of molt to birds, very little is known about its environmental or physiological control. In starlings Sturnus vulgaris, and other species, under both natural conditions and experimental regimes, gonadal regression coincides with peak prolactin secretion. The prebasic molt starts at the same time. The aim of this series of experiments was to keep starlings on photo-schedules that would challenge the normally close relationship between gonadal regression and molt, to determine how closely the start of molt is associated with gonadal regression and/or associated changes in prolactin concentrations. In one series of experiments, photosensitive starlings were moved from a short photoperiod, 8 h light per day (8L), to 13 or 18L, and from 13 to 18L or 13 to 8L during testicular maturation. Later, photorefractory birds under 13L that had finished molting were moved to 18L. In another series of experiments, photorefractory starlings were moved from 18 to 8L for 7 weeks, 4 weeks, 2 weeks, 1 week, 3 days, 1 day, or 0 days, before being returned to 18L. There was no consistent relationship between photoperiod, or the increase in photoperiod, and the timing of the start of molt. Nor was there a consistent relationship with gonadal regression and the start of molt-molt could be triggered in the absence of a gonadal cycle. However, there was always an association between the start of molt and prolactin. In all cases where molt was induced, there had been an earlier increase in prolactin. However, the timing of molt was related to the time of peak prolactin, not the magnitude of that peak. This relationship between peak prolactin and the start of molt could explain the normally close relationship between the end of breeding activity and the start of molt.

Molt chronology of northern pintails in California

USGS Publications Warehouse

Miller, M.R.

1986-01-01

Intensity and chronology of molt in 10 feather groups (head, neck, breast, belly, back, rump, side, scapular, tertial, and tail) were measured using percentages of developing feathers (pinfeathers) converted to molt scores (0-100) in samples plucked monthly from northern pintails (Anas acuta) collected by shooting from August through March 1980-82 in the Sacramento Valley, California. Data to supplement sample size of immatures were obtained from October 1982 through January 1983. Molt scores of the prealternate molt peaked (30-40% pinfeathers) in immature and adult females and adult males in October when nearly all feather groups were molting. The prealternate molt in immature males did not peak until November. Adult males nearly completed this molt by December; no new feather growth occurred after January. Immature males were still growing new neck, side, rump, scapular, and tertial feathers in December. Molt scores of the prebasic molt among adult and immature females peaked (30-40% new growth) in February in both years. The prealternate molt of breast and belly feathers (both sexes) peaked earlier (Sep) than molt of most other feathers (Oct). Increased molt scores in peak months were a function of a disproportionate increase of molt activity within each feather group and the number of feather groups with molt. Molt scores of the prebasic molt in adult females were less during December and January of the dry (1980-81) than the wet (1981-82) winter. Restriction or delay of molt may conserve energy or other nutrients during poor habitat conditions.

Testing competing hypotheses for chronology and intensity of lesser scaup molt during winter and spring migration

USGS Publications Warehouse

Anteau, Michael J.; Anteau, Andrea C.E.; Afton, Alan D.

2011-01-01

We examined chronology and intensity of molt and their relationships to nutrient reserves (lipid and protein) of Lesser Scaup (Aythya affinisK/i>) to test predictions of two competing hypotheses. The "staggered cost" hypothesis states that contour-feather molt is nutritionally costly and should not occur during nutritionally costly periods of the annual cycle unless adequate nutrients are available. The "breeding plumage" hypothesis states that prealternate molt must be complete prior to nesting, regardless of nutrient availability. Males and females were completing prebasic molt during winter (Louisiana) and had similar molt intensities. Females underwent prealternate molt during spring migration (Illinois and Minnesota) and prebreeding (Manitoba) periods; 53% and 93% of females were in moderate to heavy molt in Minnesota and Manitoba, respectively, despite experiencing other substantial nutritional costs. Intensity of prealternate molt was not correlated with lipid reserves even though females, on average, were nutritionally stressed. Molt intensity was not negatively correlated with protein reserves at any location. Chronology and intensity of prealternate molt varied little and were not temporally staggered from other nutritionally costly events. Prealternate molt did not influence nutrient reserves, and nutrient reserves likely were not the ultimate factor influencing chronology or intensity of prealternate molt of females. We surmise that nutrients required for prealternate molt come from exogenous sources and that the "staggered cost" hypothesis does not explain chronology of prealternate molt in female Lesser Scaup; rather, it appears that molt must be complete prior to nesting, consistent with the "breeding plumage" hypothesis.

Testing competing hypotheses for chronology and intensity of lesser scaup molt during winter and spring migration

USGS Publications Warehouse

Anteau, M.J.; Anteau, A.C.E.; Afton, A.D.

2011-01-01

We examined chronology and intensity of molt and their relationships to nutrient reserves (lipid and protein) of Lesser Scaup (Aythya affinis) to test predictions of two competing hypotheses. The "staggered cost" hypothesis states that contour-feather molt is nutritionally costly and should not occur during nutritionally costly periods of the annual cycle unless adequate nutrients are available. The "breeding plumage" hypothesis states that prealternate molt must be complete prior to nesting, regardless of nutrient availability. Males and females were completing prebasic molt during winter (Louisiana) and had similar molt intensities. Females underwent prealternate molt during spring migration (Illinois and Minnesota) and prebreeding (Manitoba) periods; 53% and 93% of females were in moderate to heavy molt in Minnesota and Manitoba, respectively, despite experiencing other substantial nutritional costs. Intensity of prealternate molt was not correlated with lipid reserves even though females, on average, were nutritionally stressed. Molt intensity was not negatively correlated with protein reserves at any location. Chronology and intensity of prealternate molt varied little and were not temporally staggered from other nutritionally costly events. Prealternate molt did not influence nutrient reserves, and nutrient reserves likely were not the ultimate factor influencing chronology or intensity of prealternate molt of females. We surmise that nutrients required for prealternate molt come from exogenous sources and that the "staggered cost" hypothesis does not explain chronology of prealternate molt in female Lesser Scaup; rather, it appears that molt must be complete prior to nesting, consistent with the "breeding plumage" hypothesis. ?? The Cooper Ornithological Society 2011.

Transcriptional response of mysid crustacean, Americamysis bahia, is affected by subchronic exposure to nonylphenol.

PubMed

Uchida, Masaya; Hirano, Masashi; Ishibashi, Hiroshi; Kobayashi, Jun; Kagami, Yoshihiro; Koyanagi, Akiko; Kusano, Teruhiko; Koga, Minoru; Arizono, Koji

2016-11-01

Nonylphenol (NP) has been classified as an endocrine-disrupting chemical. In this study, we conducted mysid DNA microarray analysis with which has 2240 oligo DNA probes to observe differential gene expressions in mysid crustacean (Americamysis bahia) exposed to 1, 3, 10 and 30 μg/l of NP for 14 days. As a result, we found 31, 27, 39 and 68 genes were differentially expressed in the respective concentrations. Among these genes, the expressions of five particular genes were regulated in a similar manner at all concentrations of the NP exposure. So, we focused on one gene encoding cuticle protein, and another encoding cuticular protein analogous to peritrophins 1-H precursor. These genes were down-regulated by NP exposure in a dose-dependent manner, and it suggested that they were related in a reduction of the number of molting in mysids. Thus, they might become useful molecular biomarker candidates to evaluate molting inhibition in mysids. Copyright © 2016 Elsevier Inc. All rights reserved.

Molecular evolution of the crustacean hyperglycemic hormone family in ecdysozoans

PubMed Central

2010-01-01

Background Crustacean Hyperglycemic Hormone (CHH) family peptides are neurohormones known to regulate several important functions in decapod crustaceans such as ionic and energetic metabolism, molting and reproduction. The structural conservation of these peptides, together with the variety of functions they display, led us to investigate their evolutionary history. CHH family peptides exist in insects (Ion Transport Peptides) and may be present in all ecdysozoans as well. In order to extend the evolutionary study to the entire family, CHH family peptides were thus searched in taxa outside decapods, where they have been, to date, poorly investigated. Results CHH family peptides were characterized by molecular cloning in a branchiopod crustacean, Daphnia magna, and in a collembolan, Folsomia candida. Genes encoding such peptides were also rebuilt in silico from genomic sequences of another branchiopod, a chelicerate and two nematodes. These sequences were included in updated datasets to build phylogenies of the CHH family in pancrustaceans. These phylogenies suggest that peptides found in Branchiopoda and Collembola are more closely related to insect ITPs than to crustacean CHHs. Datasets were also used to support a phylogenetic hypothesis about pancrustacean relationships, which, in addition to gene structures, allowed us to propose two evolutionary scenarios of this multigenic family in ecdysozoans. Conclusions Evolutionary scenarios suggest that CHH family genes of ecdysozoans originate from an ancestral two-exon gene, and genes of arthropods from a three-exon one. In malacostracans, the evolution of the CHH family has involved several duplication, insertion or deletion events, leading to neuropeptides with a wide variety of functions, as observed in decapods. This family could thus constitute a promising model to investigate the links between gene duplications and functional divergence. PMID:20184761

Relationship between dose of emamectin benzoate and molting response of ovigerous American lobsters (Homarus americanus).

PubMed

Waddy, S L; Merritt, V A; Hamilton-Gibson, M N; Aiken, D E; Burridge, L E

2007-05-01

A widely-prescribed treatment to control sea lice on cultured salmon is the administration of feed medicated with SLICE (active ingredient emamectin benzoate (EMB)). High doses of EMB can disrupt the molt cycle of ovigerous American lobsters, causing them to enter proecdysis prematurely and lose their attached eggs when the shell is cast. To determine the dose response to EMB, lobsters were forced to ingest doses that ranged from 0.05 to 0.39 microg g(-1). A significant proportion of lobsters given doses of 0.39 and 0.22 microg g(-1) (37% and 23%, respectively) molted prematurely, almost a year earlier than the control group. All the lobsters in the 0.05 and 0.12 microg g(-1) groups molted at the normal time and the mean time of molt was similar to that of the control group. Thus, the no-observed-effect level (NOEL) and lowest-observed-effect level (LOEL) of EMB on the molt cycle were 0.12 and 0.22 microg EMB g(-1) lobster, respectively. To acquire the LOEL, a 500-g lobster would have to consume 22 g of salmon feed medicated with SLICE at a level of 5 microg EMB g(-1) feed.

Digestive proteinases of red shrimp Pleoticus muelleri (Decapoda, Penaeoidea): partial characterization and relationship with molting.

PubMed

Fernández Gimenez, A V; García-Carreño, F L; Navarrete del Toro, M A; Fenucci, J L

2001-10-01

The present study describes the activity and some characteristics of proteinases in the hepatopancreas of red shrimp Pleoticus muelleri during the different stages of the molting cycle. Proteolytic activity was highest between pH 7.5 and 8. The hepatopancreatic protein content in the premolt stage was higher than in the other stages of the molting cycle (P<0.05). No significant differences were found in total proteolytic activity in the hepatopancreas when comparing molting stages. The proteolytic activity of the P. muelleri hepatopancreas enzyme preparations is the main responsibility of serine proteinases. TLCK, a trypsin inhibitor, reduced azocasein hydrolysis between 26% (intermolt) and 37% (premolt). TPCK, a chymotrypsin inhibitor, did not decrease hydrolytic activity, except for in postmolt. Low trypsin and chymotrypsin activities were found during intermolt, and increased in postmolt. The electrophoretogram of the enzyme extracts shows 12 bands of activity during intermolt (from 16.6 to 53.1 kDa). Some fractions were not detected in the postmolt and premolt stages. Three low molecular weight trypsin forms (17.4, 19.1 and 20 kDa) were found in all molting stages. One band of chymotrypsin (21.9 kDa) was observed in all molting stages. High molecular mass active bands (66-205 kDa) could not be characterized with inhibitors. Comparison of the protease-specific activity of the hepatopancreas of some species indicated a relationship between digestive enzyme activity and feeding habits of the shrimp. Omnivorous shrimp, such as Penaeus vannamei (syn: Litopenaeus vannamei) and Penaeus monodon, showed higher protease activity than the carnivorous shrimp, Penaeus californiensis (syn: Farfantepenaeus californiensis) and P. muelleri. In fact, the enzymatic activity in the hepatopancreas of P. muelleri showed variations in relation to feeding habit and molting cycle.

New Functions of Arthropod Bursicon: Inducing Deposition and Thickening of New Cuticle and Hemocyte Granulation in the Blue Crab, Callinectes sapidus

PubMed Central

Chung, J. Sook; Katayama, Hidekazu; Dircksen, Heinrich

2012-01-01

Arthropod growth requires molt-associated changes in softness and stiffness of the cuticle that protects from desiccation, infection and injury. Cuticle hardening in insects depends on the blood-borne hormone, bursicon (Burs), although it has never been determined in hemolymph. Whilst also having Burs, decapod crustaceans reiterate molting many more times during their longer life span and are encased in a calcified exoskeleton, which after molting undergoes similar initial cuticle hardening processes as in insects. We investigated the role of homologous crustacean Burs in cuticular changes and growth in the blue crab, Callinectes sapidus. We found dramatic increases in size and number of Burs cells during development in paired thoracic ganglion complex (TGC) neurons with pericardial organs (POs) as neurohemal release sites. A skewed expression of Burs β/Burs α mRNA in TGC corresponds to protein contents of identified Burs β homodimer and Burs heterodimer in POs. In hemolymph, Burs is consistently present at ∼21 pM throughout the molt cycle, showing a peak of ∼89 pM at ecdysis. Since initial cuticle hardness determines the degree of molt-associated somatic increment (MSI), we applied recombinant Burs in vitro to cuticle explants of late premolt or early ecdysis. Burs stimulates cuticle thickening and granulation of hemocytes. These findings demonstrate novel cuticle-associated functions of Burs during molting, while the unambiguous and constant presence of Burs in cells and hemolymph throughout the molt cycle and life stages may implicate further functions of its homo- and heterodimer hormone isoforms in immunoprotective defense systems of arthropods. PMID:23029467

Structural prediction and analysis of VIH-related peptides from selected crustacean species

PubMed Central

Nagaraju, Ganji Purna Chandra; Kumari, Nunna Siva; Prasad, Ganji Lakshmi Vara; Rajitha, Balney; Meenu, Madan; Rao, Manam Sreenivasa; Naik, Bannoth Reddya

2009-01-01

The tentative elucidation of the 3D-structure of vitellogenesis inhibiting hormone (VIH) peptides is conversely underprivileged by difficulties in gaining enough peptide or protein, diffracting crystals, and numerous extra technical aspects. As a result, no structural information is available for VIH peptide sequences registered in the Genbank. In this situation, it is not surprising that predictive methods have achieved great interest. Here, in this study the molt-inhibiting hormone (MIH) of the kuruma prawn (Marsupenaeus japonicus) is used, to predict the structure of four VIHrelated peptides in the crustacean species. The high similarity of the 3D-structures and the calculated physiochemical characteristics of these peptides suggest a common fold for the entire family. PMID:20011146

Structural prediction and analysis of VIH-related peptides from selected crustacean species.

PubMed

Nagaraju, Ganji Purna Chandra; Kumari, Nunna Siva; Prasad, Ganji Lakshmi Vara; Rajitha, Balney; Meenu, Madan; Rao, Manam Sreenivasa; Naik, Bannoth Reddya

2009-08-17

The tentative elucidation of the 3D-structure of vitellogenesis inhibiting hormone (VIH) peptides is conversely underprivileged by difficulties in gaining enough peptide or protein, diffracting crystals, and numerous extra technical aspects. As a result, no structural information is available for VIH peptide sequences registered in the Genbank. In this situation, it is not surprising that predictive methods have achieved great interest. Here, in this study the molt-inhibiting hormone (MIH) of the kuruma prawn (Marsupenaeus japonicus) is used, to predict the structure of four VIHrelated peptides in the crustacean species. The high similarity of the 3D-structures and the calculated physiochemical characteristics of these peptides suggest a common fold for the entire family.

Orchestin, a calcium-binding phosphoprotein, is a matrix component of two successive transitory calcified biomineralizations cyclically elaborated by a terrestrial crustacean.

PubMed

Hecker, Arnaud; Quennedey, Brigitte; Testenière, Olivier; Quennedey, André; Graf, François; Luquet, Gilles

2004-06-01

Orchestia cavimana is a crustacean that cyclically replaces its calcified cuticle during molting cycles in order to grow. Its terrestrial way of life requires storage of calcium during each premolt period, as calcareous concretions, in tubular diverticula of the midgut. During the postmolt period the stored calcium is reabsorbed and is translocated through the storage organ epithelium as calcified small spherules. In a previous study, we sequenced and characterized a remarkable component of the organic matrix of the premolt storage structures, Orchestin, which is a calcium-binding phosphoprotein. In this paper, we analyzed the spatiotemporal expression of the orchestin gene by Northern blotting and in situ hybridization, and its translated product by immunocytochemistry. We found evidence that the gene and the protein are expressed specifically during premolt in the storage organs. More interestingly, we demonstrated that the protein is synthesized also during the postmolt period, as a component of the organic matrix of the calcium resorption spherules. Thus, Orchestin is a matrix component that is synthesized by the same cells to contribute alternately to the elaboration of two different calcifications. These results, in addition to the physical and chemical features of the protein, suggest that Orchestin is probably a key molecule in the calcium carbonate precipitation process leading to the cyclic elaboration of two transitory calcified mineralizations by the crustacean Orchestia.

Least squares estimation of avian molt rates

USGS Publications Warehouse

Johnson, D.H.

1989-01-01

A straightforward least squares method of estimating the rate at which birds molt feathers is presented, suitable for birds captured more than once during the period of molt. The date of molt onset can also be estimated. The method is applied to male and female mourning doves.

The effect of latitude on photoperiodic control of gonadal maturation, regression and molt in birds.

PubMed

Dawson, Alistair

2013-09-01

Photoperiod is the major cue used by birds to time breeding seasons and molt. However, the annual cycle in photoperiod changes with latitude. Within species, for temperate and high latitude species, gonadal maturation and breeding start earlier at lower latitudes but regression and molt both occur at similar times at different latitudes. Earlier gonadal maturation can be explained simply by the fact that considerable maturation occurs before the equinox when photoperiod is longer at lower latitudes - genetic differences between populations are not necessary to explain earlier breeding at lower latitudes. Gonadal regression is caused either by absolute photorefractoriness or, in some species with long breeding seasons, relative photorefractoriness. In either case, the timing of regression and molt cannot be explained by absolute prevailing photoperiod or rate of change in photoperiod - birds appear to be using more subtle cues from the pattern of change in photoperiod. However, there may be no difference between absolute and relative photorefractory species in how they utilise the annual cycle in photoperiod to time regression. Copyright © 2013 Elsevier Inc. All rights reserved.

Molt patterns and weight changes of the American woodcock

USGS Publications Warehouse

Owen, R.B.; Krohn, W.B.

1973-01-01

A study of molt and changes in body weight of American Woodcock was conducted to better understand the summer and fall behavior of these birds and to indicate periods of physiological stress. The postnuptial molt of adults was a complete molt beginning in late June and ending by the middle of October. In contrast, the postjuvenal molt was a less intensive partial molt beginning in mid-July but also extending to the middle of October. Both male and female adult birds experienced weight loss in August during peak molt. Young birds gradually gained weight throughout the summer. Fat deposition was negatively correlated with molt while fall body weights were positively correlated with fat deposition. The data indicated that the majority of Maine woodcock are not physiologically prepared for migration until mid-October. Weights of adult males during the spring suggested that this is an important period of stress for these birds.

Utilizing fungus myceliated grain for molt induction and performance in commercial laying hens.

PubMed

Willis, W L; Isikhuemhen, O S; Allen, J W; Byers, A; King, K; Thomas, C

2009-10-01

Molting in poultry is used to rejuvenate hens for a second or third laying cycle. Feed withdrawal was once the most effective method used for molt induction; however, it has being phased out due to food safety and animal welfare concerns. This study evaluated the utilization of fungus myceliated grain as a safe and effective alternative for inducing molt, enhancing immunity, reducing Salmonella growth, and returning to egg production. Laying hens were subjected to 1 of 5 treatments: 1) nonfed (NF), 2) full-fed (FF), 3) fungus myceliated meal (FM), 4) 90% fungus myceliated meal+10% standard layer ration (FM-90), and 5) 90% alfalfa meal+10% fungus myceliated meal (AF-90). Each treatment condition was replicated 9 times during a 9-d molt period. The results revealed that egg production for treatments 1 and 3 ceased completely by d 5, whereas hens in treatments 4 and 5 ceased egg production by d 6. The percentage of BW loss decreased significantly (P<0.05) in treatments 1 (57%), 2 (8%), 3 (35%), 4 (37%), and 5 (44%). Ovary weights of hens fed all molting diets decreased significantly from the full-fed control but did not differ significantly (P<0.05) from each other. Salmonella population in the crop, ovary, and ceca from hens differed significantly (P<0.05) among treatments. Return to egg production differed between treatments with higher production beginning in treatment 3 and ending in treatment 5. Antibody titers did differ (P<0.05) among treatments. From these results, fungus myceliated meal appears to be a viable alternative to conventional feed withdrawal and other methods for the successful induction of molt and retention of postmolt performance.

Localization and expression of molt-inhibiting hormone and nitric oxide synthase in the central nervous system of the green shore crab, Carcinus maenas, and the blackback land crab, Gecarcinus lateralis.

PubMed

Pitts, Natalie L; Mykles, Donald L

2017-01-01

In decapod crustaceans, molting is controlled by the pulsatile release of molt-inhibiting hormone (MIH) from neurosecretory cells in the X-organ/sinus gland (XO/SG) complex in the eyestalk ganglia (ESG). A drop in MIH release triggers molting by activating the molting gland or Y-organ (YO). Post-transcriptional mechanisms ultimately control MIH levels in the hemolymph. Neurotransmitter-mediated electrical activity controls Ca 2+ -dependent vesicular release of MIH from the SG axon terminals, which may be modulated by nitric oxide (NO). In green shore crab, Carcinus maenas, nitric oxide synthase (NOS) protein and NO are present in the SG. Moreover, C. maenas are refractory to eyestalk ablation (ESA), suggesting other regions of the nervous system secrete sufficient amounts of MIH to prevent molting. By contrast, ESA induces molting in the blackback land crab, Gecarcinus lateralis. Double-label immunofluorescence microscopy and quantitative polymerase chain reaction were used to localize and quantify MIH and NOS proteins and transcripts, respectively, in the ESG, brain, and thoracic ganglion (TG) of C. maenas and G. lateralis. In ESG, MIH- and NOS-immunopositive cells were closely associated in the SG of both species; confocal microscopy showed that NOS was localized in cells adjacent to MIH-positive axon terminals. In brain, MIH-positive cells were located in a small number of cells in the olfactory lobe; no NOS immunofluorescence was detected. In TG, MIH and NOS were localized in cell clusters between the segmental nerves. In G. lateralis, Gl-MIH and Gl-crustacean hyperglycemic hormone (CHH) mRNA levels were ~10 5 -fold higher in ESG than in brain or TG of intermolt animals, indicating that the ESG is the primary source of these neuropeptides. Gl-NOS and Gl-elongation factor (EF2) mRNA levels were also higher in the ESG. Molt stage had little or no effect on CHH, NOS, NOS-interacting protein (NOS-IP), membrane Guanylyl Cyclase-II (GC-II), and NO-independent GC

Egg prices, feed costs, and the decision to molt.

PubMed

McDaniel, B A; Aske, D R

2000-09-01

On April 7, 1998, the United Poultry Concerns filed a petition with the Department of Health and Human Services of the Food and Drug Administration calling for the elimination of the practice of forced molting of laying hens in the US. In reaction to this petition, this study investigated the economic importance of forced molting as a short-term production management tool for egg producers. The relationship between shell egg prices and feed costs and the occurrence of forced molting in the five shell egg-pricing regions in the US was addressed. The purpose of this analysis was to determine whether forced molting is used to slow egg production during periods of falling or low egg prices or periods of high or rising feed costs. Ordinary least squares was used to test the relationship between the independent variables (egg, corn, and meal prices) and the dependent variable (percentage of layers in molt). In four of the five regions, there was a significant inverse relationship (P < 0.05) between egg prices and the percentage of layers in molt. This analysis suggests that producers were influenced by current egg prices when making the decision to molt. However, the relationship between the percentage of layers in molt and corn and meal prices was less clear. Although a positive relationship between feed prices and molt was found in each region, in only one region was the relationship statistically significant (P < 0.05).

Evaluation of Salmonella enteritidis in molting hens after administration of an experimental chlorate product (for nine days) in the drinking water and feeding an alfalfa molt diet.

PubMed

McReynolds, J; Kubena, L; Byrd, J; Anderson, R; Ricke, S; Nisbet, D

2005-08-01

The method most commonly used to induce molting and stimulate multiple egg-laying cycles in laying hens for commercial egg production is to fast the hens. Unfortunately, increased risk of Salmonella enteritidis (SE) infection may result from the use of this method. Methods to stimulate multiple egg-laying cycles without increasing the risk of SE infection are needed. Hens over 50 wk of age were divided into 12 groups of 11 hens each and placed in individual laying cages. One week prior to dietary changes, hens were placed on an 8-h light and 16-h dark photoperiod that continued for the 9-d molt. All hens were challenged orally with 10(6) cfu of SE on the fourth day of the molt. Treatments were nonfed hens with distilled water (NFD), nonfed hens with the experimental chlorate product (ECP, which provided 15 mM chlorate ion) water (NFECP), alfalfa diets with distilled water (ALD), and alfalfa diets with ECP water (ALECP). In the NFD hens, 67% (log10 2.74) of the crops and 94% (log10 5.62) of the ceca were colonized, whereas for the NFECP hens significant reductions to 22% (log10 1.05) of the crops and 61% (log10 2.44) of the ceca were observed. In the ALD hens, 61% (log10 2.52) of the crops and 94% (log10 4.06) of the ceca were colonized. In the ALECP hens, highly significant reductions to 11% (log10 1.26) of the crops and 39% (log10 1.12) of the ceca were observed. When compared with the NFD hens, significant reductions in SE invasion of the ovary, liver, and spleen occurred in all other treatments, except the ovary in the ALD hens. The low alfalfa intake is probably a factor in our lowered protection against SE when compared with previous results. For several parameters, these results suggest that ECP or the combination of ECP and alfalfa may be a useful tool to reduce the risk of SE during an induced molt.

Mineral deposition in bacteria-filled and bacteria-free calcium bodies in the crustacean Hyloniscus riparius (Isopoda: Oniscidea).

PubMed

Vittori, Miloš; Rozman, Alenka; Grdadolnik, Jože; Novak, Urban; Štrus, Jasna

2013-01-01

Crustacean calcium bodies are epithelial sacs which contain a mineralized matrix. The objectives of this study were to describe the microscopic anatomy of calcium bodies in the terrestrial isopod Hyloniscus riparius and to establish whether they undergo molt-related structural changes. We performed 3D reconstruction of the calcium bodies from paraffin sections and analyzed their structure with light and electron microscopy. In addition, we analyzed the chemical composition of their mineralized matrices with micro-Raman spectroscopy. Two pairs of these organs are present in H. riparius. One pair is filled with bacteria while the other pair is not. In non-molting animals, the bacteria-filled calcium bodies contain apatite crystals and the bacteria-free calcium bodies enclose CaCO3-containing concretions with little organic matrix. During preparation for molt, an additional matrix layer is deposited in both pairs of calcium bodies. In the bacteria-filled calcium bodies it contains a mixture of calcium carbonate and calcium phosphate, whereas only calcium carbonate is present in bacteria-free calcium bodies. After ecdysis, all mineral components in bacteria-free calcium bodies and the additional matrix layer in bacteria-filled calcium bodies are completely resorbed. During calcium resorption, the apical surface of the calcium body epithelium is deeply folded and electron dense granules are present in spaces between epithelial cells. Our results indicate that the presence of bacteria might be linked to calcium phosphate mineralization. Calcium bodies likely provide a source of calcium and potentially phosphate for the mineralization of the new cuticle after molt. Unlike other terrestrial isopods, H. riparius does not form sternal CaCO3 deposits and the bacteria-free calcium bodies might functionally replace them in this species.

Mineral Deposition in Bacteria-Filled and Bacteria-Free Calcium Bodies in the Crustacean Hyloniscus riparius (Isopoda: Oniscidea)

PubMed Central

Vittori, Miloš; Rozman, Alenka; Grdadolnik, Jože; Novak, Urban; Štrus, Jasna

2013-01-01

Crustacean calcium bodies are epithelial sacs which contain a mineralized matrix. The objectives of this study were to describe the microscopic anatomy of calcium bodies in the terrestrial isopod Hyloniscus riparius and to establish whether they undergo molt-related structural changes. We performed 3D reconstruction of the calcium bodies from paraffin sections and analyzed their structure with light and electron microscopy. In addition, we analyzed the chemical composition of their mineralized matrices with micro-Raman spectroscopy. Two pairs of these organs are present in H. riparius. One pair is filled with bacteria while the other pair is not. In non-molting animals, the bacteria-filled calcium bodies contain apatite crystals and the bacteria-free calcium bodies enclose CaCO3-containing concretions with little organic matrix. During preparation for molt, an additional matrix layer is deposited in both pairs of calcium bodies. In the bacteria-filled calcium bodies it contains a mixture of calcium carbonate and calcium phosphate, whereas only calcium carbonate is present in bacteria-free calcium bodies. After ecdysis, all mineral components in bacteria-free calcium bodies and the additional matrix layer in bacteria-filled calcium bodies are completely resorbed. During calcium resorption, the apical surface of the calcium body epithelium is deeply folded and electron dense granules are present in spaces between epithelial cells. Our results indicate that the presence of bacteria might be linked to calcium phosphate mineralization. Calcium bodies likely provide a source of calcium and potentially phosphate for the mineralization of the new cuticle after molt. Unlike other terrestrial isopods, H. riparius does not form sternal CaCO3 deposits and the bacteria-free calcium bodies might functionally replace them in this species. PMID:23554963

Cuticular Biominerals of the Terrestrial Crustacean Oniscus asellus (Isopoda, Linnaeus 1758)

NASA Astrophysics Data System (ADS)

Mergelsberg, S. T.; Mukhopadhyay, B.; Dove, P. M.

2013-12-01

Biomineralization is a phenomenon observed in many eukaryotic organisms and evidence suggests this process began relatively early in the evolution of multicellular life (Marin F et al. 1996). Crustaceans form a large fraction of all eukaryotic biomineralizers by incorporating calcium carbonate (CaCO3) into their cuticle. Terrestrial species are challenged in their production of CaCO3 by the absence of calcium-rich waters. To cope with this limitation, the terrestrial crustacean Oniscus asellus recycles up to 80% (Auzou G 1953) of its total calcium during the molting process. This feat is accomplished by separate molting of the front and back cuticle, with temporary storage of the calcium carbonate as amorphous calcium carbonate (ACC) in the front half (Ziegler A 1997). These processes infer a highly efficient and regulated mechanism for biomineralization that is most likely orchestrated by a myriad of proteins (Ziegler A et al. 2012). Until recently, investigations of biomineralization were largely directed toward understanding morphology and large-scale chemistry of the minerals, ignoring the mechanistic roles of biomacromolecules in mineralization processes. More recent work suggests a high involvement of these compounds on the formation of biominerals and, in some cases, the specific polymorphs thereof (Keene EC et al. 2010). This study focuses on identifying the components of the biological mineralization matrix at each stage of the process. Using chemical demineralization of the stored ACC, all biomacromolecules can be separated and purified for subsequent analysis by MALDI-TOF mass spectrometry. To link the localized biochemistry more intimately to the polymorph of calcium carbonate that forms in the animal, the inorganic phase (';the mineral') will be monitored at each life stage using XRD and TEM. This analysis will reveal the organic components of a very precise biomineralization mechanism and may shed insight on its evolutionary origin. References: Marin

Artificial rain and cold wind act as stressors to captive molting and non-molting European starlings (Sturnus vulgaris).

PubMed

de Bruijn, Robert; Romero, L Michael

2013-03-01

Free-roaming animals continually cope with changes in their environment. One of the most unpredictable environmental phenomena is weather. Being able to respond to weather appropriately is crucial as it can be a threat to survival. The stress response, consisting of increases in heart rate and release of glucocorticoids, is an important mechanism by which animals cope with stressors. This study examined behavioral, heart rate, and corticosterone responses of captive European starlings (Sturnus vulgaris) to two aspects of weather mimicked under controlled conditions, a subtle (3 °C) decrease in temperature and a short, mild bout of rain. Both decreased temperature and exposure to rain elicited increases in heart rate and corticosterone in non-molting starlings. Molt is an important life history stage in birds that affects feather cover and may require a different response to weather-related stressors. We repeated the experiment in molting starlings and found increases in heart rate in response to rain and cold wind. However, the hypothalamic-pituitary-adrenal (HPA)-axis was suppressed during molt, as molting starlings did not increase corticosterone release in response to either stimulus. These data suggest these stimuli induce increased allostatic load in starlings, and that animals may adjust their response depending on the life-history stage. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of adenosine on the growth of human T-lymphocyte leukemia cell line MOLT-4.

PubMed

Streitová, Denisa; Weiterová, Lenka; Hofer, Michal; Holá, Jirina; Horváth, Viktor; Kozubík, Alois; Znojil, Vladimír

2007-09-01

Adenosine has been observed to suppress the growth of MOLT-4 human leukemia cells in vitro. Changes in the cell cycle, especially increased percentage of cells in S phase, prolonged generation time, and induction of apoptosis at higher adenosine concentrations have been found to be responsible for the growth suppression. Dipyridamole, a drug inhibiting the cellular uptake of adenosine, reversed partially but significantly the adenosine-induced growth suppression. It follows from these results that the action of adenosine on the MOLT-4 cells comprises its cellular uptake and intracellular operation. These findings present new data on anticancer efficacy of adenosine.

Changes in timing, duration, and symmetry of molt of Hawaiian forest birds.

PubMed

Freed, Leonard A; Cann, Rebecca L

2012-01-01

Food limitation greatly affects bird breeding performance, but the effect of nutritive stress on molt has barely been investigated outside of laboratory settings. Here we show changes in molting patterns for an entire native Hawaiian bird community at 1650-1900 m elevation on the Island of Hawaii between 1989-1999 and 2000-2006, associated with severe food limitation throughout the year beginning in 2000. Young birds and adults of all species took longer to complete their molt, including months never or rarely used during the 1989-1999 decade. These included the cold winter months and even the early months of the following breeding season. In addition, more adults of most species initiated their molt one to two months earlier, during the breeding season. Suspended molt, indicated by birds temporarily not molting primary flight feathers during the months of peak primary molt, increased in prevalence. Food limitation reached the point where individuals of all species had asymmetric molt, with different primary flight feathers molted on each wing. These multiple changes in molt, unprecedented in birds, had survival consequences. Adult birds captured during January to March, 2000-2004, had lower survival in four of five species with little effect of extended molt. Extended molt may be adaptive for a nutrient stressed bird to survive warm temperatures but not cool winter temperatures that may obliterate the energy savings. The changing molt of Hawaiian birds has many implications for conservation and for understanding life history aspects of molt of tropical birds.

Flightless and post-molt survival and movements of female mallards molting in Klamath Basin

USGS Publications Warehouse

Fleskes, Joseph P.; Mauser, David M.; Yee, Julie L.; Blehert, David S.; Yarris, Gregory S.

2010-01-01

Flightless and post-molt survival and movements were studied during August-May, 2001-2002, 2002- 2003 and 2006-2007 for 181 adult female Mallards (Anas platyrhynchos). Birds were radiotagged just before or early in their flightless period on four wetlands that differed in size on Klamath Basin (KB) National Wildlife Refuge complex. Flightless survival varied among years but was higher on two larger than two smaller wetlands; 30-day survival ranged from 11% (SE = 6.5%) on a small wetland in 2006 to 93% (SE = 6.5%) on a large wetland in 2001, and averaged 76.8% (SE = 6.1%). Most flightless mortality was from avian botulism (64%) and predation (26%). Of the 81 radiotagged Mallards that did not die in KB, 80% moved to the Central Valley of California (CVCA) before 31 January, 16% wintered in unknown areas, and 4% remained in KB through 31 January. Mallards departed KB 21 August-13 January (average: 11 Nov 2001, 25 Oct 2002, 19 Nov 2006). Post-molt survival during August-March in KB (20.7%, SE = 6.3%) was lower than in CVCA during this (62.9%, SE = 10.1%) and an earlier study. Survival in KB was consistently high only for females that molted in large permanent marshes, and although the impact of poor survival of molting females on Mallard population dynamics is unknown, KB water management plans should be developed that maintain these habitats.

Changes in Timing, Duration, and Symmetry of Molt of Hawaiian Forest Birds

PubMed Central

Freed, Leonard A.; Cann, Rebecca L.

2012-01-01

Food limitation greatly affects bird breeding performance, but the effect of nutritive stress on molt has barely been investigated outside of laboratory settings. Here we show changes in molting patterns for an entire native Hawaiian bird community at 1650–1900 m elevation on the Island of Hawaii between 1989–1999 and 2000–2006, associated with severe food limitation throughout the year beginning in 2000. Young birds and adults of all species took longer to complete their molt, including months never or rarely used during the 1989–1999 decade. These included the cold winter months and even the early months of the following breeding season. In addition, more adults of most species initiated their molt one to two months earlier, during the breeding season. Suspended molt, indicated by birds temporarily not molting primary flight feathers during the months of peak primary molt, increased in prevalence. Food limitation reached the point where individuals of all species had asymmetric molt, with different primary flight feathers molted on each wing. These multiple changes in molt, unprecedented in birds, had survival consequences. Adult birds captured during January to March, 2000–2004, had lower survival in four of five species with little effect of extended molt. Extended molt may be adaptive for a nutrient stressed bird to survive warm temperatures but not cool winter temperatures that may obliterate the energy savings. The changing molt of Hawaiian birds has many implications for conservation and for understanding life history aspects of molt of tropical birds. PMID:22279547

Characterization of cDNA encoding molt-inhibiting hormone of the crab, Cancer pagurus; expression of MIH in non-X-organ tissues.

PubMed

Lu, W; Wainwright, G; Olohan, L A; Webster, S G; Rees, H H; Turner, P C

2001-10-31

Synthesis of ecdysteroids (molting hormones) by crustacean Y-organs is regulated by a neuropeptide, molt-inhibiting hormone (MIH), produced in eyestalk neural ganglia. We report here the molecular cloning of a cDNA encoding MIH of the edible crab, Cancer pagurus. Full-length MIH cDNA was obtained by using reverse transcription-polymerase chain reaction (RT-PCR) with degenerate oligonucleotides based upon the amino acid sequence of MIH, in conjunction with 5'- and 3'-RACE. Full-length clones of MIH cDNA were obtained that encoded a 35 amino acid putative signal peptide and the mature 78 amino acid peptide. Of various tissues examined by Northern blot analysis, the X-organ was the sole major site of expression of the MIH gene. However, a nested-PCR approach using non-degenerate MIH-specific primers indicated the presence of MIH transcripts in other tissues. Southern blot analysis indicated a simple gene arrangement with at least two copies of the MIH gene in the genome of C. pagurus. Additional Southern blotting experiments detected MIH-hybridizing bands in another Cancer species, Cancer antennarius and another crab species, Carcinus maenas.

Primary feather molt of adult mourning doves in North and South Carolina

USGS Publications Warehouse

Haas, G.H.; Amend, S.R.

1979-01-01

Examination of 8,141 adult mourning doves (Zenaida macroura) in North and South Carolina revealed that substantial numbers complete primary feather molt in September. Adult mourning doves shed primaries at the rate of 1 per 14 days. No difference was found in this rate between sexes or among years, 1969-74. The initiation of molt differed from year to year, and female molt always preceded male molt. Available data show that southern doves complete primary molt a month earlier than northern doves. Therefore, age based on primary molt can be biased upward if all molt-complete wings from southern hunting samples are considered immature.

Progress of primary feather molt of adult mourning doves in Missouri

USGS Publications Warehouse

Sadler, K.C.; Tomlinson, R.E.; Wight, H.M.

1970-01-01

The examination of 7,892 adult doves in Missouri between 1953 and 1965 showed that less than 2.5% of adult doves completed their molt before October 1. Adult doves of both sexes began molting their primary feathers during early June in Missouri and lost the last (tenth) primary during the latter half of October. Approximately 140-150 days were required to complete the molt. Thus, early-hatched immatures, which begin their primary molt 25-30 days after hatching, contributed the bulk of the wings with completed molts in September. By correctly classifying September samples of dove wings with a completed molt as young-of-the-year a more accurate young:adult ratio is obtained.

The Involvement of Hemocyte Prophenoloxidase in the Shell-Hardening Process of the Blue Crab, Callinectes sapidus

PubMed Central

Alvarez, Javier V.; Chung, J. Sook

2015-01-01

Cuticular structures of arthropods undergo dramatic molt-related changes from being soft to becoming hard. The shell-hardening process of decapod crustaceans includes sclerotization and mineralization. Hemocyte PPO plays a central role in melanization and sclerotization particularly in wound healing in crustaceans. However, little is known about its role in the crustacean initial shell-hardening process. The earlier findings of the aggregation of heavily granulated hemocytes beneath the hypodermis during ecdysis imply that the hemocytes may be involved in the shell-hardening process. In order to determine if hemocytes and hemocyte PPO have a role in the shell-hardening of crustaceans, a knockdown study using specific CasPPO-hemo-dsRNA was carried out with juvenile blue crabs, Callinectes sapidus. Multiple injections of CasPPO-hemo-dsRNA reduce specifically the levels of CasPPO-hemo expression by 57% and PO activity by 54% in hemocyte lysate at the postmolt, while they have no effect on the total hemocyte numbers. Immunocytochemistry and flow cytometry analysis using a specific antiserum generated against CasPPO show granulocytes, semigranulocytes and hyaline cells as the cellular sources for PPO at the postmolt. Interestingly, the type of hemocytes, as the cellular sources of PPO, varies by molt stage. The granulocytes always contain PPO throughout the molt cycle. However, semigranulocytes and hyaline cells become CasPPO immune-positive only at early premolt and postmolt, indicating that PPO expression in these cells may be involved in the shell-hardening process of C. sapidus. PMID:26393802

Molt and taxonomy of red-breasted nuthatches

USGS Publications Warehouse

Banks, R.C.

1970-01-01

The postnuptial and postjuvenal molts of Red-breasted Nuthatches occur from middle June to late September. Some birds may be nearly finished with the complete molt before other individuals begin, so that specimens taken at any given time may differ by as much as two months in the age of their plumage. No characters useful in ageing birds after the completion of the autumn molt were found.....The proposed racial subdivision of Sitta canadensis was based on misleading evidence resulting from variation of plumage age in birds assumed to be seasonally comparable, sooting of birds in industrialized parts of the country, and variation in quality of prepared specimens.

Analysis of snail genes in the crustacean Parhyale hawaiensis: insight into snail gene family evolution.

PubMed

Hannibal, Roberta L; Price, Alivia L; Parchem, Ronald J; Patel, Nipam H

2012-05-01

The transcriptional repressor snail was first discovered in Drosophila melanogaster, where it initially plays a role in gastrulation and mesoderm formation, and later plays a role in neurogenesis. Among arthropods, this role of snail appears to be conserved in the insects Tribolium and Anopheles gambiae, but not in the chelicerates Cupiennius salei and Achaearanea tepidariorum, the myriapod Glomeris marginata, or the Branchiopod crustacean Daphnia magna. These data imply that within arthropoda, snail acquired its role in gastrulation and mesoderm formation in the insect lineage. However, crustaceans are a diverse group with several major taxa, making analysis of more crustaceans necessary to potentially understand the ancestral role of snail in Pancrustacea (crustaceans + insects) and thus in the ancestor of insects as well. To address these questions, we examined the snail family in the Malacostracan crustacean Parhyale hawaiensis. We found three snail homologs, Ph-snail1, Ph-snail2 and Ph-snail3, and one scratch homolog, Ph-scratch. Parhyale snail genes are expressed after gastrulation, during germband formation and elongation. Ph-snail1, Ph-snail2, and Ph-snail3 are expressed in distinct patterns in the neuroectoderm. Ph-snail1 is the only Parhyale snail gene expressed in the mesoderm, where its expression cycles in the mesodermal stem cells, called mesoteloblasts. The mesoteloblasts go through a series of cycles, where each cycle is composed of a migration phase and a division phase. Ph-snail1 is expressed during the migration phase, but not during the division phase. We found that as each mesoteloblast division produces one segment's worth of mesoderm, Ph-snail1 expression is linked to both the cell cycle and the segmental production of mesoderm.

[The mechanisms of p21WAF1/Cip-1 expression in MOLT-4 cell line induced by TSA].

PubMed

Song, Yi; Liu, Mei-Ju; Zhao, Guo-Wei; Qian, Jun-Jie; Dong, Yan; Liu, Hua; Sun, Guo-Jing; Mei, Zhu-Zhong; Liu, Bin; Tian, Bao-Lei; Sun, Zhi-Xian

2005-04-01

To investigate the function and molecular mechanism of p21(WAF1/Cip-1) expression in MOLT-4 cells induced by HDAC inhibitor TSA, the expression pattern of p21(WAF1/Cip-1) and the distribution of cell cycle in TSA treated cells were analyzed. The results showed that TSA could effectively induce G(2)/M arrest and apoptosis of MOLT-4 cells. Kinetic experiments demonstrated that p21(WAF1/Cip-1) were upregulated quickly before cell arrested in G(2)/M and began decreasing at the early stage of apoptosis. Meanwhile, the proteasome inhibitor MG-132 could inhibit the decrease of p21(WAF1/Cip-1) at the early stage of apoptosis, which showed that proteasome pathway involved in p21(WAF1/Cip-1) degradation during the TSA induced G(2)/M arrest and apoptosis responses. This study also identified that the protein level of p21(WAF1/Cip-1) was highly associated with the cell cycle change induced by TSA. Compared to cells treated by TSA only, exposure MOLT-4 cells to TSA meanwhile treatment with MG-132 increased the protein level of p21(WAF1/Cip-1) and increased the numbers of cell in G(2)/M-phase, whereas the cell apoptosis were delayed. It is concluded that p21(WAF1/Cip-1) plays a significant role in G(2)/M arrest and apoptosis signaling induced by TSA in MOLT-4 cells.

Shifts in the distribution of molting Spectacled Eiders (Somateria fischeri) indicate ecosystem change in the Arctic

USGS Publications Warehouse

Sexson, Matthew; Petersen, Margaret; Breed, Greg A.; Powell, Abby N.

2016-01-01

Shifts in the distribution of benthivorous predators provide an indication of underlying environmental changes in benthic-mediated ecosystems. Spectacled Eiders (Somateria fischeri) are benthivorous sea ducks that spend the nonbreeding portion of their annual cycle in the Bering, Chukchi, Beaufort, and East Siberian seas. Sea ducks generally molt in biologically productive areas with abundant prey. If the distribution of eiders at molting areas matches prey abundance, spatial shifts may indicate changes in environmental conditions in the Arctic. We used a randomization procedure to test for shifts in the distribution of satellite telemetry locations received from Spectacled Eiders in the 1990s and 2008–2011 within 4 late-summer, ice-free molting areas: Indigirka–Kolyma, northern Russia; Ledyard Bay, eastern Chukchi Sea; Norton Sound, northeastern Bering Sea; and Mechigmenskiy Gulf, northwestern Bering Sea. We also tested for interannual and interdecadal changes in dive depth required to reach prey, which might affect the energetic costs of foraging during the molting period. Transmitter-marked birds used each molting area in each year, although the distribution of Spectacled Eiders shifted within each area. Interdecadal shifts in Ledyard Bay and Norton Sound decreased dive depth in recent years, although minor differences in depth were biologically negligible in relation to the energetic expense of feather growth. Shifts in Mechigmenskiy Gulf and Indigirka–Kolyma did not occur consistently within or among decades, which suggests greater interannual variability among environmental factors that influence distribution in these areas. Shifts in each molting area suggest dynamic ecosystem processes, with implications for Spectacled Eiders if changes result in novel competition or predation, or in shifting prey regimes.

Molting Mania

ERIC Educational Resources Information Center

Arce, Christina

2006-01-01

Most children are unaware of the process of molting, the periodic shedding and replacement of part or all of a coat or an outer covering of an animal, but it is an animal characteristic they are sure to be interested in and should have the opportunity to observe. In this article, the author shares how she and her students observed various…

Season, molt, and body size influence mercury concentrations in grebes

USGS Publications Warehouse

Hartman, Christopher; Ackerman, Joshua T.; Herzog, Mark; Eagles-Smith, Collin A.

2017-01-01

We studied seasonal and physiological influences on mercury concentrations in western grebes (Aechmophorus occidentalis) and Clark's grebes (A. occidentalis) across 29 lakes and reservoirs in California, USA. Additionally, at three of these lakes, we conducted a time series study, in which we repeatedly sampled grebe blood mercury concentrations during the spring, summer, and early fall. Grebe blood mercury concentrations were higher among males (0.61 ± 0.12 μg/g ww) than females (0.52 ± 0.10 μg/g ww), higher among Clark's grebes (0.58 ± 0.12 μg/g ww) than western grebes (0.51 ± 0.10 μg/g ww), and exhibited a strong seasonal pattern (decreasing by 60% from spring to fall). Grebe blood THg concentrations exhibited a shallow, inverse U-shaped pattern with body size, and was lowest among the smallest and largest grebes. Further, the relationship between grebe blood mercury concentrations and wing primary feather molt exhibited a shallow U-shaped pattern, where mercury concentrations were highest among birds that had not yet begun molting, decreased approximately 24% between pre-molt and late molt, and increased approximately 19% from late molt to post-molt. Because grebes did not begin molting until mid-summer, lower grebe blood mercury concentrations observed in late summer and early fall were consistent with the onset of primary feather molt. However, because sampling date was a much stronger predictor of grebe mercury concentrations than molt, other seasonally changing environmental factors likely played a larger role than molt in the seasonal variation in grebe mercury concentrations. In the time series study, we found that seasonal trends in grebe mercury concentrations were not consistent among lakes, indicating that lake-specific variation in mercury dynamics influence the overall seasonal decline in grebe blood mercury concentrations. These results highlight the importance of accounting for sampling date, as well as ecological processes that may

Flight feather molt in Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) in North Dakota

USGS Publications Warehouse

Twedt, Daniel J.; Linz, George M.

2015-01-01

Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) in central North Dakota undergo prebasic molt or prejuvenile molt during late summer. Nestling Yellow-headed Blackbirds initiate a complete prejuvenile molt, grow their primary and secondary regimes in about 40 days, completing molt after they leave the nest by the first week in August. Remiges are not replaced during the subsequent preformative molt, being retained until the second prebasic molt. Nonlinear (logistic) regression of primary remex growth during definitive prebasic molts of Yellow-headed Blackbirds indicated 38 days were required to complete the linear phase of growth (between 10% and 90% of total primary length). Males added 19.5 mm/d and females added 15.7 mm/d to the total length of all primaries during this linear growth phase; an average of 4–5 mm per primary remex per day. Definitive prebasic molting of primary remiges in males and females was initiated in late June, after nesting and brood rearing were completed. Molts of Yellow-headed Blackbirds were completed by early September, before birds emigrated from North Dakota during mid-September. Because of their comparatively early completion of molt and emigration from the state, as well as their more diverse diet, agricultural depredation caused by Yellow-headed Blackbirds in North Dakota is likely less than that of Red-winged Blackbirds and Common Grackles.

LIFE CYCLE, DISTRIBUTION AND ABUNDANCE OF CARCINONEMERTES EPIALTI, A NEMERTEAN EGG PREDATOR OF THE SHORE CRAB, HEMIGRAPSUS OREGONENSIS, IN RELATION TO HOST SIZE, REPRODUCTION AND MOLT CYCLE.

PubMed

Kuris, Armand M

1978-02-01

1. The geographic range of Carcinonemertes epialti has been greatly extended. The worms are found from Bahia San Quintin, Baja California, Mexico, to Page's Lagoon, Vancouver Island, British Columbia, Canada. 2. New host records for C. epialti include H. oregonensis, and H. nudus. It is rare on its type host Pugettia producta. Specimens of Carcinonemertes of uncertain affinities are also found on Cancer antennarius, C. anthonyi and C. productus. 3. Carcinonemertes epialti adults are egg predators on ovigerous hosts. Growth, demography and abundance are described in relation to the embryogenic stage of the host brood at Bodega Harbor, California. 4. Nonfeeding juveniles are ensheathed on individuals of both host sexes over 8.0 mm carapace width. 5. Transmission experiments show that contact transfer of juvenile nemerteans from males to other hosts may occur. 6. The percentage of infestation and mean density peak in autumn on H. oregonensis at Bodega Harbor. 7. Ovigerous female hosts are more frequently infested with C. epialti, particularly at small host sizes, than are male or nonovigerous female hosts at Bodega Harbor. However, average worm density on ovigerous females is low. 8. Mean density of C. epialti rises through late postmolt, declines during intermolt and rebuilds to a high level in late premolt H. oregonensisfrom Bodega Harbor. 9. Large crabs have a higher percentage of infestations and mean densities per infection than do small crabs. Nemerteans are more frequently found in the sternal-abdominal furrow and less frequently in the limb axillae on large crabs. 10. A model of C. epialti transmission and site occupancy is proposed, incorporating the influence of host size, sex, reproductive state, embryogenesis, molt cycle stage and molt cycle duration of H. oregonensis at Bodega Harbor. Site availability increases with host size. At higher densities the juvenile nemerteans increasingly occupy less preferred sites. Transferral of juvenile nemerteans occurs

The timing of wing molt in tundra swans: energetic and non-energetic constraints

USGS Publications Warehouse

Earnst, S.L.

1992-01-01

Date of wing molt initiation, based on the regression of tenth primary length on capture date, was calculated for breeding and nonbreeding Tundra Swans (Cygnus columbianus columbianus) on the Colville River Delta, Alaska. Breeding females initiated wing molt significantly later than breeding males and nonbreeding males and females; the molt of breeding females was correlated with the date on which their eggs hatched. Breeding males did not differ significantly from nonbreeding males and females in the date of molt initiation. Timing of molt in breeding males and females was consistent with the views that females delay molt while replenishing energy spent on reproduction, but was also consistent with the breeding pair's need for primaries to defend territories and to defend and brood young. Other results, including an increase in an index of female body condition throughout most of the molt period, and a positive correlation between clutch size and female hatch-to-molt interval, were not predicted by the hypothesis that past energy expenditures constrain the timing of molt. Patterns of wing molt within and among other Northern Hemisphere geese and swans are also difficult to explain on the basis of energetics alone. For example, breeding females initiate molt before breeding males in many species. Also, there is extreme asynchrony between mates in two swan species; one of those species also exhibits variation in which sex initiates wing molt first. Both patterns suggest that asynchrony, per se, is important, probably to facilitate brood protection or territory defense. In Tundra Swans and other northern breeding geese and swans, the non-energetic demands of territory defense, brood defense, and brooding are probably important constraints on the timing of wing molt.

Season, molt, and body size influence mercury concentrations in grebes.

PubMed

Hartman, C Alex; Ackerman, Joshua T; Herzog, Mark P; Eagles-Smith, Collin A

2017-10-01

We studied seasonal and physiological influences on mercury concentrations in western grebes (Aechmophorus occidentalis) and Clark's grebes (A. occidentalis) across 29 lakes and reservoirs in California, USA. Additionally, at three of these lakes, we conducted a time series study, in which we repeatedly sampled grebe blood mercury concentrations during the spring, summer, and early fall. Grebe blood mercury concentrations were higher among males (0.61 ± 0.12 μg/g ww) than females (0.52 ± 0.10 μg/g ww), higher among Clark's grebes (0.58 ± 0.12 μg/g ww) than western grebes (0.51 ± 0.10 μg/g ww), and exhibited a strong seasonal pattern (decreasing by 60% from spring to fall). Grebe blood THg concentrations exhibited a shallow, inverse U-shaped pattern with body size, and was lowest among the smallest and largest grebes. Further, the relationship between grebe blood mercury concentrations and wing primary feather molt exhibited a shallow U-shaped pattern, where mercury concentrations were highest among birds that had not yet begun molting, decreased approximately 24% between pre-molt and late molt, and increased approximately 19% from late molt to post-molt. Because grebes did not begin molting until mid-summer, lower grebe blood mercury concentrations observed in late summer and early fall were consistent with the onset of primary feather molt. However, because sampling date was a much stronger predictor of grebe mercury concentrations than molt, other seasonally changing environmental factors likely played a larger role than molt in the seasonal variation in grebe mercury concentrations. In the time series study, we found that seasonal trends in grebe mercury concentrations were not consistent among lakes, indicating that lake-specific variation in mercury dynamics influence the overall seasonal decline in grebe blood mercury concentrations. These results highlight the importance of accounting for sampling date, as well as ecological processes

Timing of breeding and molting in six species of Hawaiian honeycreepers

USGS Publications Warehouse

Ralph, C.J.; Fancy, S.G.

1994-01-01

The timing of breeding and molting was studied in six species of Hawaiian honeycreepers with differing food habits on the Island of Hawaii. The availability of nectar was highly seasonal, whereas insect abundance was relatively constant throughout the year. All six species of honeycreeper had extended breeding and molting periods with peak breeding between April and July and peak molting in August. Breeding and molting periods for Apapane (Himatione sanguinea) and Iiwi (Vestiaria coccinea), two nectarivorous species, were shorter than those for the more insectivorous Common Amakihi (Hemignathus virens), Hawaii Creeper (Oreomystis mana), Akepa (Loxops coccineus), and Akiapolaau (Hemignathus munroi). Missing or growing flight feathers and either a brood patch or enlarged cloacal protuberance occurred simultaneously in only 3.2% of 2.786 adult birds examined. Although overlap of breeding and molting was rare, some individuals may have been able to allocate energy resources to both activities because of low clutch size, extended brooding of young, and a low rate of molting.

Molting and cuticle deposition in the subterranean trichoniscid Titanethes albus (Crustacea, Isopoda)

PubMed Central

Vittori, Miloš; Kostanjšek, Rok; Žnidaršič, Nada; Štrus, Jasna

2012-01-01

Abstract Terrestrial isopods are a suitable group for the study of cuticle synthesis and calcium dynamics because they molt frequently and have evolved means to store calcium during molt. Little data is currently available on molting in Synocheta and subterranean isopods. We studied the molting dynamics in the subterranean trichoniscid Titanethes albus under laboratory conditions and performed a microscopic investigation of sternal CaCO3 deposits and the tergal epithelium during molt in this species. In accordance with its lower metabolic rate, molting in the laboratory is roughly 2–3 times less frequent in Titanethes albus than would be expected for an epigean isopod under similar conditions. Animals assumed characteristic postures following the molt of each body half and did not consume the posterior exuviae after posterior molt. The structure of sternal calcium deposits and the ultrastructural characteristics of the epidermis during cuticle formation in Titanethes albus are similar to those described in representatives of Ligiidae. During the deposition of the exocuticle, the apical plasma membrane of epidermal cells forms finger-like extensions and numerous invaginations. In the ecdysial space of individuals in late premolt we observed cellular extensions surrounded by bundles of tubules. PMID:22536097

The involvement of prolactin in avian molt: the effects of gender and breeding success on the timing of molt in Mute swans (Cygnus olor).

PubMed

Dawson, A; Perrins, C M; Sharp, P J; Wheeler, D; Groves, S

2009-04-01

The aim of the study was to test the hypothesis that decreasing plasma prolactin stimulates or permits the initiation of avian molt. Changes in the concentration of plasma prolactin in Mute swans (Cygnus olor) were compared in non-breeding singletons and breeding pairs. In breeding swans, the onset of molt is delayed compared to non-breeders, and is delayed further in breeding males compared to their female partners. The seasonal decrease in prolactin in non-breeding birds of both sexes started at the end of May and was associated with the initiation of molt 4 weeks later. The decrease in plasma prolactin in incubating females was more pronounced, as a consequence of increased prolactin secretion associated with incubation behavior, but also started at end of May, and was associated the onset of molt 6 weeks later. In breeding males, plasma prolactin increased at the end of May when they started to care for their newly hatched cygnets. Correspondingly, prolactin began to decrease 3-5 weeks later in males than in females. These males started to molt in mid August, at least 4 weeks later than females. It is concluded that molt is related to decreasing plasma prolactin, and is inhibited when plasma prolactin is increasing or high.

Post-molting development of wind-elicited escape behavior in the cricket.

PubMed

Sato, Nodoka; Shidara, Hisashi; Ogawa, Hiroto

2017-11-01

Arthropods including insects grow through several developmental stages by molting. The abrupt changes in their body size and morphology accompanying the molting are responsible for the developmental changes in behavior. While in holometabolous insects, larval behaviors are transformed into adult-specific behaviors with drastic changes in nervous system during the pupal stage, hemimetabolous insects preserve most innate behaviors whole life long, which allow us to trace the maturation process of preserved behaviors after the changes in body. Wind-elicited escape behavior is one of these behaviors and mediated by cercal system, which is a mechanosensory organ equipped by all stages of nymph in orthopteran insects like crickets. However, the maturation process of the escape behavior after the molt is unclear. In this study, we examined time-series of changes in the wind-elicited escape behavior just after the imaginal molt in the cricket. The locomotor activities are developed over the elapsed time, and matured 24h after the molt. In contrast, a stimulus-angle dependency of moving direction was unchanged over time, meaning that the cercal sensory system detecting airflow direction was workable immediately after the molt, independent from the behavioral maturation. The post-molting development of the wind-elicited behavior was considered to result not simply from maturation of the exoskeleton or musculature because the escape response to heat-shock stimulus did not change after the molt. No effect of a temporal immobilization after the imaginal molt on the maturation of the wind-elicited behavior also implies that the maturation may be innately programmed without experience of locomotion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molting Site Fidelity in Workers of Formosan Subterranean Termites (Isoptera: Rhinotermitidae).

PubMed

Kakkar, G; Osbrink, W; Mullins, A; Su, N-Y

2017-12-05

Spatial assessment of molting in workers of Coptotermes formosanus Shiraki was conducted in laboratory-reared colonies using extended foraging arenas. Workers at a premolt stage were found concentrated in the nest or in a planar arena near the nest. However, molting individuals were found exclusively in the central nest and they stayed inside or near the central nest for at least 36 h postmolting. The absence of premolt workers at foraging sites suggests that the workers have an affinity to the nest for molting and the second study on nest-fidelity evaluation suggested that the workers molt in the proximity of eggs. The molting site fidelity by workers in a colony ensures that speeding up the time for mortality induced by chitin synthesis inhibitor (CSI) baits will not result in an inhibitory cascade of dead termites around the bait stations. Thus, speeding up the elimination of a C. formosanus colony using CSI baits with the addition of molt-accelerating compounds will not lead to secondary repellency. Reasons for the molting-site fidelity amongst workers in a colony are discussed. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Post-breeding population dynamics indicate upslope molt-migration by Wilson's Warblers

Treesearch

Andrew K. Wiegardt; Daniel C. Barton; Jared D. Wolfe

2017-01-01

Molt is an energetically costly process, and songbirds (Order Passeriformes) exhibit a diversity of strategies to maximize their survival and reproductive success while meeting the energetic demands of the annual prebasic molt. Nearctic-Neotropic migrants in western North America commonly exhibit one of three strategies: (1) remain in breeding areas to molt, (2)...

Temporal Assessment of Molting in Workers of Formosan Subterranean Termites (Isoptera: Rhinotermitidae).

PubMed

Kakkar, G; Chouvenc, T; Osbrink, W; Su, N-Y

2016-10-01

Molt frequency of workers in laboratory-reared juvenile colonies and foraging population from field colonies of Coptotermes formosanus Shiraki was determined using planar arenas in laboratory. Given that, chitin synthesis inhibitor (CSI)-incorporated baits disrupt the molting process of workers that comprises the major population of a termite colony, temporal assessment of molting frequency in workers can give insights into potential methods of reducing the time to eliminate a CSI-baited colony. In our study the 10-d observation of juvenile colonies of C. formosanus suggested average daily molting incidence of workers in a colony is 1.7 ±  0.3% (mean ± SD). The results from a time lapse study on foraging population of workers showed that on average there is a 44-d intermolt period for second-instar workers molting to third instar and 45 d for third-instar workers molting to fourth instar. At low temperature (21 °C), molting frequency of workers (0.6% per day) was significantly lower than that of workers at 27 °C (2.2% per day). Information from this study suggests that time to molt is an important component of total time for eliminating colonies treated with CSI baits and reduction in time lapse between two consecutive molts may reduce the time required for colony elimination. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Temporal and spatial shifts in habitat use by Black Brant immediately following flightless molt

USGS Publications Warehouse

Lewis, Tyler L.; Flint, Paul L.; Schmutz, Joel A.; Derksen, Dirk V.

2010-01-01

Each year thousands of Pacific Black Brant (Branta bernicla nigricans) undergo flightless wing molt in the Teshekpuk Lake Special Area (TLSA), Alaska, in two distinct habitats: inland, freshwater lakes and coastal, brackish wetlands. Brant lose body mass during wing molt and likely must add reserves upon regaining flight to help fuel their 2,500 km migration to autumn staging areas. We characterized movements and habitat use by Brant during post-molt (the period immediately following the recovery of flight) by (1) marking individual Brant with GPS (global positioning system) transmitters, and (2) conducting a series of replicate aerial surveys. Individuals molting in inland habitats promptly abandoned their molt wetland during the post-molt and moved into coastal habitats. Consequently, inland habitats were nearly deserted by early August when Brant had regained flight, a decrease of >5,000 individuals from the flightless period of early July. Conversely, coastal molting Brant largely remained in coastal habitats during the post-molt and many coastal wetlands were occupied by large flocks (>1,000 birds). Our results indicate that inland, freshwater wetlands were less suitable post-molt habitats for Brant, while coastal wetlands were preferred as they transitioned from flightless molt. The immediacy with which Brant vacated inland habitats upon regaining flight suggests that food may be limiting during molt and they are not selecting inland molt sites strictly for food resources, but rather a balance of factors including predator avoidance and acquisition of protein for feather growth. Our data clearly demonstrate that patterns of habitat use by Brant in the TLSA change over the course of the molt season, an important consideration for management of future resource development activities in this area.

Populations, feeding ecology and molt of Steller's Eiders

USGS Publications Warehouse

Petersen, Margaret R.

1981-01-01

This study considers the temporal and spatial distribution of Steller's Eiders (Polysticta stelleri) during molt along the north side of the Alaska Peninsula from Port Heiden to Bechevin Bay. Subadult eiders molted primarily at Nelson Lagoon, adult males at Nelson Lagoon and Izembek Bay, and adult females primarily at Izembek Bay. Only a few eiders used Bechevin Bay, Seal Islands, and Port Heiden. Although the flightless period overlapped among different age and sex classes, subadults were flightless first, then adult males, and last, adult females. Eiders maintained spatial and temporal separation during the flightless period, thereby reducing competition for food resources.Eiders at Nelson Lagoon were observed feeding only by head-dipping during the pre-flightless period in 1979, a significant change from 1977 when they fed both by diving and dipping. During both 1977 and 1979 eiders foraged for approximately equal amounts of time during each stage of molt. Foods consisted primarily of bivalve mollusks and amphipods. These foods were consumed in different proportions before and after the wing-feather molt, with mussels being most important when eiders were growing remiges. Comparisons between the amount of energy in blue mussels (Mytilus edulis), clams (Macoma balthica), and gammarid amphipods showed that mussels yield the most energy per gram of whole wet weight. Apparently Steller's Eiders have adjusted to the increased energy demands of molt by eating invertebrates with high caloric content, rather than by increasing the amount of time feeding.

Identification of molting fluid carboxypeptidase A (MF-CPA) in Bombyx mori.

PubMed

Ote, Manabu; Mita, Kazuei; Kawasaki, Hideki; Daimon, Takaaki; Kobayashi, Masahiko; Shimada, Toru

2005-07-01

Using microarray analyses, we identified carboxypeptidase A (MF-CPA), which was induced during pupal ecdysis in the wing discs of Bombyx mori. Here, we report the functional characterization of MF-CPA. MF-CPA has amino acid sequence similarities with the proteins in the carboxypeptidase A/B subfamily, from human to nematode. The MF-CPA gene is expressed during the molting periods in the epithelial tissues. MF-CPA is detected in the molting fluid, which fills the space between the old and new cuticle during molting. By Western blot analysis, we show that MF-CPA is secreted as a zymogen and processed in the molting fluid. Recombinant MF-CPA expressed in the insect cells has carboxypeptidase A activity. We propose that MF-CPA degrades the proteins from the old cuticle during the molting periods and contributes to recycling of the amino acids.

Fasting in king penguin. II. Hormonal and metabolic changes during molt.

PubMed

Cherel, Y; Leloup, J; Le Maho, Y

1988-02-01

The coincidence of fast and molt in penguins is an interesting condition for investigating the factors controlling protein metabolism; avian molt involves the utilization of amino acids for synthesis of new feathers, whereas a major factor for adaptation to fasting in birds, as for mammals, is reduction in net protein breakdown. Hormonal and biochemical changes were studied in seven molting king penguins. Their initial body mass was 18 kg. It decreased by 58% over 41 days of fasting. Feather synthesis lasted for the first 3 wk of the fast. It was marked by plasma concentrations of alanine and uric acid 1.5 to 2 times those for nonmolting fast, and plasma thyroxine was increased five times. At the completion of molt all these values returned to levels comparable to those in nonmolting fast. As indicated by high plasma levels of beta-hydroxybutyrate, lipid stores were mobilized readily during molting. The fast ended by a phase of enhancement in protein utilization that was characterized by a fivefold increase in uricacidemia and coincided with an 80% drop in plasma beta-hydroxybutyrate and a fourfold increase in plasma corticosterone. These data suggest that two different hormones control the two successive periods marked by an increased protein mobilization during the molting fast, i.e., thyroxine during feather growth and corticosterone toward the end of the fast, when the molt is completed.

Breeding chronology, molt, and measurements of accipiter hawks in northeastern Oregon

USGS Publications Warehouse

Henny, C.J.; Olson, R.A.; Fleming, T.L.

1985-01-01

Most northern goshawks completed laying eggs in April, while most Cooper's hawks completed their clutches in May with essentially no overlap. The sharp-shinned hawks laid in late May and June. Juvenile females represented 4% of the northern goshawk breeding population; 22% of the Cooper's hawk breeding population (highest reported for the species) and 60% of the sharp-shinned hawk breeding population, northern goshawks and Cooper's hawks in juvenal plumage generally nested later in the season, but not sharp-shinned hawks. Females of each species began molting first. Primaries were molted from the innermost outward in all species, but rectrix molt sequence was variable. Usually R1 was molted first. Primary molt of the 2 wings was usually synchronous; however, the rectrix molt was not as orderly. Arrested molt was observed in some individuals of all species; it probably has an energy-saving function. Wing chords of adult northern goshawks from Oregon were not different from Wisconsin fall migrants or birds from Alaska; however, rectrices were significantly shorter in Oregon than Wisconsin. Cooper's hawks nesting in Oregon were much smaller than those trapped in Wisconsin. Wing chords and rectrices were significantly shorter for both sexes, and, although weights were not directly comparable, Oregon Cooper's hawks also weighed much less. The limited number of sharp-shinned hawks measured precluded statistical analyses.

Mallard (Anas platyrhynchos) mortality and recovery rates vary by wing molt status at time of banding

USGS Publications Warehouse

Fleskes, Joseph P.; Halstead, Brian J.; Kohl, Jeffrey D.; Yarris, Gregory S.

2017-01-01

Recovery (i.e., shot, retrieved, and reported) rates and daily mortality risk of 52,330 adult Mallards (Anas platyrhynchos) leg-banded during pre-molt, in-molt, or post-molt during 1985–2011 were evaluated to better understand mortality during wing molt in dynamics of the Mallard population in California, USA. Recovery rates and non-hunting mortality risk varied by molt status at time of banding and California region where banded. Mallards banded during post-molt were 1.22 (95% credible interval = 1.10–1.32) times more likely to be recovered than Mallards banded pre-molt; recovery probability was similar for pre-molt and in-molt Mallards. Mallards banded post-molt had 0.43 (0.17–0.98) and in-molt 0.87 (0.51–1.49) times the daily risk of non-hunting mortality as Mallards banded pre-molt. Mallards were 0.92 (0.86–0.98) times as likely to be recovered, and daily risk of non-hunting mortality was 2.93 (1.79–4.94) times greater, if banded in Northeastern California than in California's Central Valley. Results indicate that high mortality during the molt period, especially in Northeastern California where most Mallards that breed in California molt, might be negatively affecting recovery (and potentially annual survival) of Mallards in California. Thus, conservation programs that reduce mortality during molt could help attain the desired population size for Mallards nesting in California.

Body molt of male long-tailed ducks in the nearshore waters of the north slope, Alaska

USGS Publications Warehouse

Howell, M.D.; Grand, J.B.; Flint, Paul L.

2003-01-01

We examined the timing and intensity of body molt in relation to stage of remige growth for postbreeding adult male Long-tailed Ducks (Clangula hyemalis) off the coast of northern Alaska. During this period, remige and rectrix feathers are molted simultaneously with body feathers during the prebasic molt, which results in a period of increased energetic and nutritional demands. We collected birds from late July through mid-August and recorded intensity of molt in eight regions: head and neck, back and rump, greater coverts, lesser coverts, flank and sides, breast, belly, and tail. Using nonlinear regression, we estimated the peak intensity and variation for each region in relation to ninth primary length. We found little evidence of molt in the head and neck region. The greater and lesser coverts, and back and rump reached peak molt intensities earliest and were followed by tail, breast, and belly. Molt intensity in the flank and side region was highly variable and indicated a more prolonged molting pattern in relation to other regions. While body molt occurs simultaneously with wing molt, we found that molt among regions occurred in a staggered pattern. Long-tailed Ducks may employ this staggered molting pattern to minimize the energetic and nutritional requirements of molt.

Environmental endocrine disruption in decapod crustacean larvae: hormone titers, cytochrome P450, and stress protein responses to heptachlor exposure.

PubMed

Snyder, M J; Mulder, E P

2001-11-12

A variety of enzymes and other proteins are produced by organisms in response to xenobiotic exposures. Cytochrome P450s (CYP) are one of the major phase I-type classes of detoxification enzymes found in terrestrial and aquatic organisms ranging from bacteria to vertebrates. One of the primary functions of stress proteins (HSPs) is to aid in the recovery of damaged proteins by chaperoning their refolding. These and other biomarkers of xenobiotic exposure and resulting effects have not been studied in crustacean larvae. This information is of potential importance for environmental management and risk assessment. In this work, we have given Homarus americanus larvae single 24 h exposures to the cyclodiene pesticide heptachlor, a known environmental endocrine disruptor (EDC) on different days of the 1st larval instar. We followed these larvae during the first larval stage for effects on timing of ecdysis to 2nd stage, ecdysteroid molting hormone titers, and alterations in the levels of cytochrome P450 CYP45 and HSP70 proteins. Delays in ecdysis were correlated with alterations in ecdysteroid levels. This result provides clues that this pesticide may function as an environmental endocrine disruptor in crustaceans. CYP45 and HSP70 levels were significantly elevated for several days following heptachlor exposure. The elevation in HSP70 was prolonged depending on the day of pesticide exposure and this was directly related to the increase in mortality. These results demonstrate the utility of these measurements as potential biomarkers in crustacean larval developmental toxicology and EDC effects research.

The lunar-tide cycle viewed by crustacean and mollusc gatherers in the State of Paraíba, Northeast Brazil and their influence in collection attitudes

PubMed Central

Nishida, Alberto K; Nordi, Nivaldo; Alves, Rômulo RN

2006-01-01

Traditional human communities have a wide knowledge of their environment. Collection of animals in estuarine and coastal areas are directly influenced by tidal cycles. The aim of this study is to evaluate the understanding of the tides associated with the lunar cycle held by people who gather crustaceans and molluscs in the State of Paraiba. The empirical knowledge of 20 crab gatherers and 30 mollusc gatherers was recorded through open interviews and structured questionnaires. The results showed that the gatherers have an accurate comprehension of tidal phenomenon based on their exploitation of natural resources, which perpetuates through generations. PMID:16393342

Evidence for wing molt and breeding site fidelity in King Eiders

USGS Publications Warehouse

Phillips, Laura M.; Powell, A.N.

2006-01-01

Fidelity of King Eiders (Somateria spectabilis) to breeding and wing molt sites was examined using satellite telemetry data obtained opportunistically when battery life of transmitters provided locations in a second year. Consecutive breeding locations were obtained for eleven female and 23 male King Eiders. All females exhibited breeding site fidelity by returning to sites within 15 km of first year breeding areas on the North Slope of Alaska. Breeding locations of males in a subsequent year were located on average >1000 km from their prior breeding sites and were primarily outside Alaska, on the coasts of Russia and Canada. Second-year wing molt locations were obtained for two female and six male King Eiders. Wing molt sites of males were located 6.2 ?? 3.1 km apart on average in successive years, while female wing molt locations averaged almost 50 km apart. Our results demonstrate site fidelity of female King Eiders to a breeding area on the North Slope of Alaska, document the dispersal of male King Eiders between breeding seasons, and present the first evidence for wing molt site fidelity in males.

Chronic repeated exposure to weather-related stimuli elicits few symptoms of chronic stress in captive molting and non-molting European starlings (Sturnus vulgaris).

PubMed

de Bruijn, Robert; Reed, J Michael; Romero, L Michael

2017-10-01

Repeated exposure to acute stressors causes dramatic changes in an animal's stress physiology and the cumulative effects are often called chronic stress. Recently we showed that short-term exposure to weather-related stimuli, such as temperature change, artificial precipitation, and food restriction, cause acute responses in captive European starlings (Sturnus vulgaris). Here, we examined the effect of repeated exposure to weather-related stressors on heart rate and corticosterone (CORT) of captive non-molting and molting European starlings. Four times every day for 3 weeks, birds were exposed to either 30 min of a subtle (3°C) decrease in temperature, a short bout of simulated rain, or 2 hr of food removal. The order and time of presentation were randomly assigned on each day. We found no differences in heart rate or heart rate variability. Furthermore, there were no changes in baseline CORT levels, CORT negative feedback efficacy, or maximal adrenal capacity. Mass increased across the experimental period only in molting birds. CORT responses to restraint were decreased in both groups following treatment, suggesting the birds had downregulated their responses to acute stress. Molting birds showed evidence of suppression of the HPA axis compared with non-molting birds, which is consistent with previous research. Overall, our data show that repeated exposure to weather-related stressors does not elicit most of the symptoms normally associated with chronic stress. © 2018 Wiley Periodicals, Inc.

Tapping the Power of Crustacean Transcriptomics to Address Grand Challenges in Comparative Biology: An Introduction to the Symposium.

PubMed

Mykles, Donald L; Burnett, Karen G; Durica, David S; Stillman, Jonathon H

2016-12-01

Crustaceans, and decapods in particular (i.e., crabs, shrimp, and lobsters), are a diverse and ecologically and commercially important group of organisms. Understanding responses to abiotic and biotic factors is critical for developing best practices in aquaculture and assessing the effects of changing environments on the biology of these important animals. A relatively small number of decapod crustacean species have been intensively studied at the molecular level; the availability, experimental tractability, and economic relevance factor into the selection of a particular species as a model. Transcriptomics, using high-throughput next generation sequencing (NGS, coupled with RNA sequencing or RNA-seq) is revolutionizing crustacean biology. The 11 symposium papers in this volume illustrate how RNA-seq is being used to study stress response, molting and limb regeneration, immunity and disease, reproduction and development, neurobiology, and ecology and evolution. This symposium occurred on the 10th anniversary of the symposium, "Genomic and Proteomic Approaches to Crustacean Biology", held at the Society for Integrative and Comparative Biology 2006 meeting. Two participants in the 2006 symposium, the late Paul Gross and David Towle, were recognized as leaders who pioneered the use of molecular techniques that would ultimately foster the transcriptomics research reviewed in this volume. RNA-seq is a powerful tool for hypothesis-driven research, as well as an engine for discovery. It has eclipsed the technologies available in 2006, such as microarrays, expressed sequence tags, and subtractive hybridization screening, as the millions of "reads" from NGS enable researchers to de novo assemble a comprehensive transcriptome without a complete genome sequence. The symposium series concludes with a policy paper that gives an overview of the resources available and makes recommendations for developing better tools for functional annotation and pathway and network analysis in

Complex Population Responses to Food Resources in the Marine Crustacean Americamysis Bahia

EPA Science Inventory

Most observations of stressor effects on marine crustaceans are made on individuals or even-aged cohorts. Results of these studies are difficult to translate into ecological predictions, either because life cycle models are incomplete, or because stressor effects on mixed age po...

Analysis of gene expression in the midgut of Bombyx mori during the larval molting stage.

PubMed

Yang, Bing; Huang, Wuren; Zhang, Jie; Xu, Qiuyun; Zhu, Shoulin; Zhang, Qiaoli; Beerntsen, Brenda T; Song, Hongsheng; Ling, Erjun

2016-11-03

Insects can be models for understanding human intestinal infection and pathology. Molting, a special period during which the old insect cuticle is shed and a new one is produced, is crucial for insect development. Holometabolous insects may experience several larva-to-larva moltings to become larger, a pupal molt and adult eclosion to become adults. During the larval molts, they stop feeding and become quiescent. Although the molting larvae become quiescent, it is not known if changes in microbiome, physiology, development and immunity of midguts occur. Transcriptome analysis indicated that functions such as metabolism, digestion, and transport may become reduced due to the downregulated expression of many associated genes. During the molting stage, midguts harbor less microflora and DNA synthesis decreases. Both ecdysone and juvenile hormone in the larval midgut likely degrade after entering the larva-to-larva molting stage. However, at 12 h after ecdysis, the feeding larvae of 5th instars that were injected with 20-hydroxyecdysone entered a molting-like stage, during which changes in midgut morphology, DNA synthesis, gene expression, and microflora exhibited the same patterns as observed in the actual molting state. This study is important for understanding insect midgut physiology, development and immunity during a special development stage when no food is ingested. Although the molting larva becomes immobile and quiescent, we demonstrate that numerous changes occur in midgut morphology, physiology, metabolism and microbiome during this period.

The relationship of blue crab (Callinectes sapidus) size class and molt stage to disease acquisition and intensity of Hematodinium perezi infections.

PubMed

Lycett, Kristen A; Chung, J Sook; Pitula, Joseph S

2018-01-01

In the blue crab, Callinectes sapidus, early studies suggested a relationship between smaller crabs, which molt more frequently, and higher rates of infection by the dinoflagellate parasite, Hematodinium perezi. In order to better explore the influence of size and molting on infections, blue crabs were collected from the Maryland coastal bays and screened for the presence of H. perezi in hemolymph samples using a quantitative PCR assay. Molt stage was determined by a radioimmunoassay which measured ecdysteroid concentrations in blue crab hemolymph. Differences were seen in infection prevalence between size classes, with the medium size class (crabs 61 to 90 mm carapace width) and juvenile crabs (≤ 30 mm carapace width) having the highest infection prevalence at 47.2% and 46.7%, respectively. All size classes were susceptible to infection, although fall months favored disease acquisition by juveniles, whereas mid-sized animals (31-90 mm carapace width) acquired infection predominantly in summer. Disease intensity was also most pronounced in the summer, with blue crabs > 61 mm being primary sources of proliferation. Molt status appeared to be influenced by infection, with infected crabs having significantly lower concentrations of ecdysteroids than uninfected crabs in the spring and the fall. We hypothesize that infection by H. perezi may increase molt intervals, with a delay in the spring molt cycle as an evolutionary adaptation functioning to coincide with increased host metabolism, providing optimal conditions for H. perezi propagation. Regardless of season, postmolt crabs harbored significantly higher proportions of moderate and heavy infections, suggesting that the process of ecdysis, and the postmolt recovery period, has a positive effect on parasite proliferation.

Neural mechanism of optimal limb coordination in crustacean swimming

PubMed Central

Zhang, Calvin; Guy, Robert D.; Mulloney, Brian; Zhang, Qinghai; Lewis, Timothy J.

2014-01-01

A fundamental challenge in neuroscience is to understand how biologically salient motor behaviors emerge from properties of the underlying neural circuits. Crayfish, krill, prawns, lobsters, and other long-tailed crustaceans swim by rhythmically moving limbs called swimmerets. Over the entire biological range of animal size and paddling frequency, movements of adjacent swimmerets maintain an approximate quarter-period phase difference with the more posterior limbs leading the cycle. We use a computational fluid dynamics model to show that this frequency-invariant stroke pattern is the most effective and mechanically efficient paddling rhythm across the full range of biologically relevant Reynolds numbers in crustacean swimming. We then show that the organization of the neural circuit underlying swimmeret coordination provides a robust mechanism for generating this stroke pattern. Specifically, the wave-like limb coordination emerges robustly from a combination of the half-center structure of the local central pattern generating circuits (CPGs) that drive the movements of each limb, the asymmetric network topology of the connections between local CPGs, and the phase response properties of the local CPGs, which we measure experimentally. Thus, the crustacean swimmeret system serves as a concrete example in which the architecture of a neural circuit leads to optimal behavior in a robust manner. Furthermore, we consider all possible connection topologies between local CPGs and show that the natural connectivity pattern generates the biomechanically optimal stroke pattern most robustly. Given the high metabolic cost of crustacean swimming, our results suggest that natural selection has pushed the swimmeret neural circuit toward a connection topology that produces optimal behavior. PMID:25201976

Topographical and typological comparison of the rodlike setae of ambulatory dactylopodites in decapod crustaceans

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

Hamilton, K.A.

1983-01-01

The arrangement and external morphology of the rodlike setae and associated structures located on the dactylopodites of the walking legs of six species of decapod crustaceans are compared. The dactyls of littoral species, represented by the rock crab, Cancer antennarius, and the spiny lobster, Panulirus interruptus, have dense tufts and bands of rodlike setae, as is typical of many decapods, and additionally only a few small plumed setae. The arrangement of setae on the dactyls of the recently discovered Galapagos vent crab. Bythograea thermydron, closely resembles that of C. antennarius. Rodlike and long plumed setae occur in about equal numbersmore » on the dactyls of the pelagic anomuran, Pleuroncodes planipes. The dactyls having the fewest rodlike setae are those of the terrestrial hermit crab, Coenobita perlatus, and those of the kelp crab, Pugettia producta, where flat setae typical of Majidae have replace most rodlike setae. The presence and structures of the terminal pores in rodlike setae vary intra- and interspecifically, possibly as a function of molt stage. Variations in some features of rodlike setae, such as tip acuity and presence of microsetae and surface sculpting, appear to be related to development. Serrated setae occur on the dactyls of megalopal P. producta but not in later stages. The topography and typolgy of setae located on the ambulatory dactyls of decapod crustaceans are considered in light of recent interest in using seta characteristics to determine the sensory functions of sensilla and to clarify the phylogeny of arthropod groups.« less

Transcriptome sequencing of newly molted adult female cattle ticks, Rhipicephalus microplus: Raw Illumina reads.

USDA-ARS?s Scientific Manuscript database

Illumina paired end oligo-dT sequencing technology was used to sequence the transcriptome from newly molted adult females from the cattle tick, Rhipicephalus microplus. These samples include newly molted unfed whole adult females, newly molted whole adult females feeding for 2 hours on a bovine host...

Knickkopf protein protects and organizes chitin in the newly synthesized insect exoskeleton

PubMed Central

Chaudhari, Sujata S.; Arakane, Yasuyuki; Specht, Charles A.; Moussian, Bernard; Boyle, Daniel L.; Park, Yoonseong; Kramer, Karl J.; Beeman, Richard W.; Muthukrishnan, Subbaratnam

2011-01-01

During each molting cycle of insect development, synthesis of new cuticle occurs concurrently with the partial degradation of the overlying old exoskeleton. Protection of the newly synthesized cuticle from molting fluid enzymes has long been attributed to the presence of an impermeable envelope layer that was thought to serve as a physical barrier, preventing molting fluid enzymes from accessing the new cuticle and thereby ensuring selective degradation of only the old one. In this study, using the red flour beetle, Tribolium castaneum, as a model insect species, we show that an entirely different and unexpected mechanism accounts for the selective action of chitinases and possibly other molting enzymes. The molting fluid enzyme chitinase, which degrades the matrix polysaccharide chitin, is not excluded from the newly synthesized cuticle as previously assumed. Instead, the new cuticle is protected from chitinase action by the T. castaneum Knickkopf (TcKnk) protein. TcKnk colocalizes with chitin in the new cuticle and organizes it into laminae. Down-regulation of TcKnk results in chitinase-dependent loss of chitin, severe molting defects, and lethality at all developmental stages. The conservation of Knickkopf across insect, crustacean, and nematode taxa suggests that its critical roles in the laminar ordering and protection of exoskeletal chitin may be common to all chitinous invertebrates. PMID:21930896

Knickkopf protein protects and organizes chitin in the newly synthesized insect exoskeleton.

PubMed

Chaudhari, Sujata S; Arakane, Yasuyuki; Specht, Charles A; Moussian, Bernard; Boyle, Daniel L; Park, Yoonseong; Kramer, Karl J; Beeman, Richard W; Muthukrishnan, Subbaratnam

2011-10-11

During each molting cycle of insect development, synthesis of new cuticle occurs concurrently with the partial degradation of the overlying old exoskeleton. Protection of the newly synthesized cuticle from molting fluid enzymes has long been attributed to the presence of an impermeable envelope layer that was thought to serve as a physical barrier, preventing molting fluid enzymes from accessing the new cuticle and thereby ensuring selective degradation of only the old one. In this study, using the red flour beetle, Tribolium castaneum, as a model insect species, we show that an entirely different and unexpected mechanism accounts for the selective action of chitinases and possibly other molting enzymes. The molting fluid enzyme chitinase, which degrades the matrix polysaccharide chitin, is not excluded from the newly synthesized cuticle as previously assumed. Instead, the new cuticle is protected from chitinase action by the T. castaneum Knickkopf (TcKnk) protein. TcKnk colocalizes with chitin in the new cuticle and organizes it into laminae. Down-regulation of TcKnk results in chitinase-dependent loss of chitin, severe molting defects, and lethality at all developmental stages. The conservation of Knickkopf across insect, crustacean, and nematode taxa suggests that its critical roles in the laminar ordering and protection of exoskeletal chitin may be common to all chitinous invertebrates.

Molt and aging criteria for four North American grassland passerines

USGS Publications Warehouse

Pyle, Peter; Jones, Stephanie L.; Ruth, Janet M.

2008-01-01

Prairie and grassland habitats in central and western North America have declined substantially since settlement by Europeans (Knopf 1994) and many of the birds and other organisms that inhabit North American grasslands have experienced steep declines (Peterjohn and Sauer 1999; Johnson and Igl 1997; Sauer, Hines, and Fallon 2007). The species addressed here, Sprague’s Pipit (Anthus spragueii), Grasshopper (Ammodramus savannarum) and Baird’s (A. bairdii) sparrows, and Chestnut-collared Longspurs (Calcarius ornatus), are grassland birds that are of special conservation concern throughout their ranges due to declining populations and the loss of the specific grassland habitats required on both their breeding and wintering ranges (Knopf 1994, Davis and Sealy 1998, Davis 2003, Davis 2004, Jones and Dieni 2007). Population-trend data on grassland birds, while clearly showing declines, provides no information on the causes of population declines. Without demographic information (i.e., productivity and survivorship), there are no means to determine when in their life cycle the problems that are creating these declines are occurring, or to determine to what extent population trends are driven by factors that affect birth rates, death rates, or both (DeSante 1995). For migratory birds, population declines may be driven by factors on breeding grounds, during migration, and/or on wintering grounds. Lack of data on productivity and survivorship thus impedes the formulation of effective management and conservation strategies to reverse population declines (DeSante 1992). Furthermore, if deficiencies in survivorship are revealed, management strategies may need to address habitats on both breeding and non-breeding grounds, as well as along migratory pathways. One technique that helps inform management strategies is the biochemical analysis of isotopes and genetic markers, from the sampling of individual feathers from live birds (Smith et al. 2003, Pérez and Hobson 2006

Molt and reproduction enhancement together with hemolymph ecdysteroid elevation under eyestalk ablation in the female fiddler crab, Uca triangularis (Brachyura: Decapoda)

NASA Astrophysics Data System (ADS)

Supriya, Nagathinkal T.; Sudha, Kappalli; Krishnakumar, Velayudhannair; Anilkumar, Gopinathan

2017-05-01

We present the results of eyestalk extirpation experiments performed on the fiddler crab, Uca triangularis at seasons of molting and reproduction, with a view to have a better understanding of the regulatory mechanisms of these two highly energy-demanding processes. Bilateral eyestalk ablation resulted in precocious acceleration of both molting and reproduction, irrespective of the season at which each experiment was conducted. The rate of accelerated ovarian growth, however, was maximum if the eyestalk ablation was conducted during August-January, the breeding season in the wild, or in February-May (molting-reproductive season), wherein a section of the wild population would be engaged in molting and another section in breeding. The highest degree of precocious molt acceleration, on the other hand, was obtained during June-July when the population was primarily engaged in molting, but with no reproductive activity. The precocious oocyte maturation (due to de-eyestalking) was minimal in June-July. Significantly, the eyestalk ablation also resulted in a dramatic increase in the hemolymph ecdysteroid titer, revealing that a high ecdysteroid titer would have no restraining influence on vitellogenesis. No spawning was, however, observed among de-eyestalked females, even though their final oocyte size surpassed the size of the normal mature oocytes, implying that spawning is not exclusively under the control of eyestalk hormones. A comparative study performed on the vitelline components of the experimentals and the controls revealed that the precociously incorporated yolk under eyestalk ablation was biochemically impoverished. These results indicate that throughout the annual cycle, both the somatic and the reproductive growth of U. triangularis are under the influence of inhibitory principles from the eyestalks. It is also revealing that mere deprival of the inhibitory principles does not culminate into successful vitellogenesis. Arguably, the inhibitory influence from

Haste Makes Waste but Condition Matters: Molt Rate–Feather Quality Trade-Off in a Sedentary Songbird

PubMed Central

Vágási, Csongor I.; Pap, Péter L.; Vincze, Orsolya; Benkő, Zoltán; Marton, Attila; Barta, Zoltán

2012-01-01

Background The trade-off between current and residual reproductive values is central to life history theory, although the possible mechanisms underlying this trade-off are largely unknown. The ‘molt constraint’ hypothesis suggests that molt and plumage functionality are compromised by the preceding breeding event, yet this candidate mechanism remains insufficiently explored. Methodology/Principal Findings The seasonal change in photoperiod was manipulated to accelerate the molt rate. This treatment simulates the case of naturally late-breeding birds. House sparrows Passer domesticus experiencing accelerated molt developed shorter flight feathers with more fault bars and body feathers with supposedly lower insulation capacity (i.e. shorter, smaller, with a higher barbule density and fewer plumulaceous barbs). However, the wing, tail and primary feather lengths were shorter in fast-molting birds if they had an inferior body condition, which has been largely overlooked in previous studies. The rachis width of flight feathers was not affected by the treatment, but it was still condition-dependent. Conclusions/Significance This study shows that sedentary birds might face evolutionary costs because of the molt rate–feather quality conflict. This is the first study to experimentally demonstrate that (1) molt rate affects several aspects of body feathers as well as flight feathers and (2) the costly effects of rapid molt are condition-specific. We conclude that molt rate and its association with feather quality might be a major mediator of life history trade-offs. Our findings also suggest a novel advantage of early breeding, i.e. the facilitation of slower molt and the condition-dependent regulation of feather growth. PMID:22808221

Hormonal treatment and flight feather molt in immature Sandhill Cranes

USGS Publications Warehouse

Gee, G.F.; Lewis, J.C.

1982-01-01

Molt, the production of a new generation of feathers, is a poorly understood physiological phenomenon in nondomestic birds. Often in large birds like geese, flight is restricted by clipping the primary remiges on 1 wing and flight is restored after the molt when the primaries are replaced. A similar technique would be desirable for use with cranes conditioned for release to the native habitat. However, immature sandhill cranes (Grus canadensis) did not appear to replace their primaries annually; therefore, we studied their flight feather molt (from 4 months to 3.5 years of age) and attempted to influence molting. Under natural conditions tail feathers (rectrices) were replaced annually and all secondaries replaced in 2.5-year-old birds. However, replacement of primaries in immature sandhill cranes appears to be a gradual process beginning the 2nd year; about 33% of the original primaries (present at 10 months of age) persisted in the 3.5-year-oId birds. Pulling out the primaries of immature sandhill cranes induces the growth of new primaries, as is true of many other birds. However, the new primaries were incapable of supporting flight, fell out repeatedly, and those that remained were often deformed. Pulling the primaries, under the influence of tranquilizers and anesthetics to relax the feather papillae, also did not induce normal growth of the replacement primaries. Progesterone (including excessively high doses), thyroxine, and follicle stimulating hormone, although effective in inducing feather replacement in domestic poultry, had no effect on crane molt.

Temporal assessment of molting in workers of Formosan subterranean termites (Isoptera: Rhinotermitidae)

USDA-ARS?s Scientific Manuscript database

Molt frequency of workers in laboratory-reared juvenile colonies and foraging population from field colonies of Coptotermes formosanus Shiraki was determined using planar arenas in laboratory. Given that, chitin synthesis inhibitor (CSI)-incorporated baits disrupt the molting process of workers that...

Gene Silencing in Crustaceans: From Basic Research to Biotechnologies

PubMed Central

Sagi, Amir; Manor, Rivka; Ventura, Tomer

2013-01-01

Gene silencing through RNA interference (RNAi) is gaining momentum for crustaceans, both in basic research and for commercial development. RNAi has proven instrumental in a growing number of crustacean species, revealing the functionality of novel crustacean genes essential among others to development, growth, metabolism and reproduction. Extensive studies have also been done on silencing of viral transcripts in crustaceans, contributing to the understanding of the defense mechanisms of crustaceans and strategies employed by viruses to overcome these. The first practical use of gene silencing in aquaculture industry has been recently achieved, through manipulation of a crustacean insulin-like androgenic gland hormone. This review summarizes the advancements in the use of RNAi in crustaceans, and assesses the advantages of this method, as well as the current hurdles that hinder its large-scale practice. PMID:24705266

An improved extraction method to increase DNA yield from molted feathers

Treesearch

Shelley Bayard De Volo; Richard T. Reynolds; Marlis R. Douglas; Michael F. Antolin

2008-01-01

To assess the value of molted feathers as a noninvasive source of DNA for genetic studies of Northern Goshawks (Accipiter gentilis), we isolated and quantified DNA from molted feathers and compared yields across five feather types. We also compared PCR success across the same five feather types using five microsatellite genetic markers of varying...

Laboratory Studies on Molting and Growth of the Shore Crab, Hemigrapsus sanguineus de Haan, Parasitized by a Rhizocephalan Barnacle.

PubMed

Takahashi, T; Matsuura, S

1994-06-01

Molting of shore crabs (Hemigrapsus sanguineus) parasitized by rhizocephalans (Sacculina senta) was observed in the laboratory, and the growth of the molted crabs was compared with that of unparasitized animals. Molting of the host was obstructed by the infestation, but was still possible. After the release of several broods of larvae, the externa (the external reproductive system of the parasite) detached from the host. Subsequent molting occurred within 40 days in about 80% of the animals, but in the remainder, it was delayed for at most 4 months. Soon after molting, a new externa protruded from the abdomen of every crab. Thus, the life-span of the externa and the molting of the host would seem to be closely connected. In the female, the molt frequency was reduced, but the molt increment of the parasitized crabs was not different from that in the unparasitized ones. In the male, however, both the molt frequency and the molt increment were reduced. Thus, the annual growth of parasitized males and females was about half that of unparasitized crabs.

Fossil Crustaceans as Parasites and Hosts.

PubMed

Klompmaker, Adiël A; Boxshall, Geoff A

2015-01-01

Numerous crustacean lineages have independently moved into parasitism as a mode of life. In modern marine ecosystems, parasitic crustaceans use representatives from many metazoan phyla as hosts. Crustaceans also serve as hosts to a rich diversity of parasites, including other crustaceans. Here, we show that the fossil record of such parasitic interactions is sparse, with only 11 examples, one dating back to the Cambrian. This may be due to the limited preservation potential and small size of parasites, as well as to problems with ascribing traces to parasitism with certainty, and to a lack of targeted research. Although the confirmed stratigraphic ranges are limited for nearly every example, evidence of parasitism related to crustaceans has become increasingly more complete for isopod-induced swellings in decapods so that quantitative analyses can be carried out. Little attention has yet been paid to the origin of parasitism in deep time, but insight can be generated by integrating data on fossils with molecular studies on modern parasites. In addition, there are other traces left by parasites that could fossilize, but have not yet been recognized in the fossil record. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of drinking water treatment on susceptibility of laying hens to Salmonella enteritidis during forced molt.

PubMed

Kubena, L F; Byrd, J A; Moore, R W; Ricke, S C; Nisbet, D J

2005-02-01

Feed deprivation is used in the layer industry to induce molting and stimulate multiple egg-laying cycles in laying hens. Unfortunately, the stress involved increases susceptibility to Salmonella enteritidis (SE), the risk of SE-positive eggs, and incidence of SE in internal organs. Leghorn hens over 50 wk of age were divided into 4 treatment groups of 12 hens each in experiment 1 and 3 treatment groups of 12 hens in experiments 2 and 3; hens were placed in individual laying hen cages. Treatment groups were 1) nonmolted (NM) and received feed and distilled water for 9 d, 2) force molted by feed removal for 9 d and received distilled water, 3) force molted by feed removal for 9 d and received 0.5% lactic acid (LA) in distilled water. An additional group (4) in experiment 1 only was force molted by feed removal for 9 d and received 0.5% acetic acid in distilled water. Seven days before feed removal hens were exposed to an 8L:16D photoperiod, which was continued throughout the experiment. Individual hens among all treatments were challenged orally with 10(4) SE on d 4 of feed removal. When compared with the NM treatments, weight losses were significantly higher in the M treatments, regardless of water treatments. When compared with NM treatments, crop pH was significantly higher in the M treatment receiving distilled water. Crop pH was reduced to that of the NM controls by 0.5% acetic acid in the drinking water. No consistent significant changes were observed for volatile fatty acids. The number of hens positive for SE in crop and ceca after culture and the number of SE per crop and per gram of cecal contents were higher in the M treatments, when compared with the NM treatments, but there was no effect of addition of either of the acids to the drinking water. Additional research using different acid treatment regimens may provide a tool for reducing the incidence of SE in eggs and internal organs during and following molting of laying hens.

Molt cycle related changes and effect of short term starvation on the biochemical constituents of the blue swimmer crab Portunus pelagicus

PubMed Central

Sugumar, V.; Vijayalakshmi, G.; Saranya, K.

2012-01-01

Synthesis and hardening of a new exoskeleton are essential to the arthropod molting process. The present study emphasizes the variations in the levels of hemolymph total free sugars, hepatopancreas glycogen and cuticular proteins during the molting stages of Portunus pelagicus. It also reports the effect of short-term starvation conditions on the biochemical constituents of the hemolymph. Intermolt crabs were subjected to 6 days of starvation and hemolymph samples were taken. Standard biochemical procedures were followed toward the quantification of total proteins, total free sugars and total lipids. The total free sugar level in the hemolymph of P. pelagicus was observed to increase during early premolt D0 (3.108 ± 0.032 g/ml) and a gradual decrease till late postmolt B stage (0.552 ± 0.124 g/ml), suggesting the need for total free sugars to provide energy for the apolysis process. Increase in the levels of hepatopancreas glycogen was observed from 1225 ± 0.04 μg/mg in early premolt D0 to 1700 ± 0.3 μg/mg in late premolt D2–3. This is in correlation with the decreased levels of free sugars during premolt stages, suggesting an increase in the storage of glycogen reserves in the hepatopancreas. Cuticular proteins increased during stage B (2.702 ± 0.093 g/ml) and stage C (3.065 ± 0.012 g/ml), indicating exoskeleton hardening and mineralization. Results of the starvation studies clearly showed a steady decline in the level of total free sugars till day 6 (0.099 ± 0.00 g/ml) when compared to the control (8.646 ± 0.08 g/ml). Gradual decrease of total lipids was also observed from the first day of the experiment (6.088 ± 2.44 g/ml) to the last day of the study (0.401 ± 0.20 g/ml) which was 85% lesser than the control (8.450 ± 0.49 g/ml)suggesting the efficient usage of total sugars to consolidate the loss of energy reserves during starvation. The knowledge of Molt-cycle events can be used as a tool for the evaluation of

Inverse Demographic Analysis of Compensatory Responses to Resource Limitation in the Mysid Crustacean Americamysis bahia

EPA Science Inventory

Most observations of stressor effects on marine crustaceans are made on individuals or even-aged cohorts. Results of these studies are difficult to translate into ecological predictions, either because life cycle models are incomplete, or because stressor effects on mixed age po...

Body condition, food habits, and molt status of late-wintering ruddy ducks in California

USGS Publications Warehouse

Hohman, W.L.; Ankney, C.D.; Roster, D.L.

1992-01-01

We studied body condition, food habits, and molt status of late-wintering ruddy ducks (Oxyura jamaicensis) using drainwater evaporation ponds in the southern San Joaquin Valley, California. Levels of body fat and protein were similar by sex but varied by age (adults greater than immatures). Masses of breast and leg muscle protein were greatest in adult males and lowest in immature males, but similar in adult and immature females. Fat and protein levels in late-wintering ruddy ducks were independent of their body size. We detected no differences among sex-age classes in the proportion of animal foods consumed. Aquatic invertebrates composed 85% of the diet; midge larvae (Diptera: Chironomidae) and brine flies (Diptera: Ephydridae) were the principal taxa consumed. Molt score by feather region and overall molt score did not vary by sex or age. Light to moderate molt (25 to 50% molting feathers) was recorded in all feather regions. High levels of body fat and protein were attributed to premigratory hyperphagia and consumption of foods with a high protein:energy ratio.

An insect-like mushroom body in a crustacean brain

PubMed Central

Wolff, Gabriella Hannah; Thoen, Hanne Halkinrud; Marshall, Justin; Sayre, Marcel E

2017-01-01

Mushroom bodies are the iconic learning and memory centers of insects. No previously described crustacean possesses a mushroom body as defined by strict morphological criteria although crustacean centers called hemiellipsoid bodies, which serve functions in sensory integration, have been viewed as evolutionarily convergent with mushroom bodies. Here, using key identifiers to characterize neural arrangements, we demonstrate insect-like mushroom bodies in stomatopod crustaceans (mantis shrimps). More than any other crustacean taxon, mantis shrimps display sophisticated behaviors relating to predation, spatial memory, and visual recognition comparable to those of insects. However, neuroanatomy-based cladistics suggesting close phylogenetic proximity of insects and stomatopod crustaceans conflicts with genomic evidence showing hexapods closely related to simple crustaceans called remipedes. We discuss whether corresponding anatomical phenotypes described here reflect the cerebral morphology of a common ancestor of Pancrustacea or an extraordinary example of convergent evolution. PMID:28949916

The Effect of Temperature on Synchronization of Brood Development of the Bopyrid Isopod Parasite Probopyrus pandalicola with Molting of Its Host, the Daggerblade Grass Shrimp Palaemonetes pugio.

PubMed

Brinton, Brigette A; Curran, Mary Carla

2015-08-01

The bopyrid isopod Probopyrus pandalicola is a hematophagous ectoparasite that sexually sterilizes some palaemonid shrimps, including female daggerblade grass shrimp Palaemonetes pugio. The reproduction of parasitic isopods is thought to occur synchronously with host molting because the brood would be unsuccessful if molting occurred before the larvae were free swimming. Temperature affects the length of the molting cycle of shrimp, and therefore may also affect the incubation time of isopod broods. The purpose of the present study was to determine the effect of temperature on brood development of the parasite and on the degree of synchronization with the molting of its host. Parasitized P. pugio were monitored daily at 2 experimental temperatures, 23 and 15 C, in temperature-controlled chambers for the duration of a full parasite reproductive cycle. Developmental stage was determined by the visible coloration of the brood through the exoskeleton of the host, and was designated as egg, embryo I, embryo II, or epicaridium larvae. Temperature significantly affected median brood incubation time, which was only 11 days at 23 C, as compared to 35 days at 15 C. The final developmental stage (epicaridium larvae) was 3 times shorter at 23 C (median 3 days; n = 45) than at 15 C (median 9 days; n = 15). Temperature significantly affected the intermolt period of parasitized shrimp, which was shorter at 23 C (median 12 days) than at 15 C (median 37 days). A smaller percentage of the intermolt period elapsed between larval release and shrimp molting at 23 C (0.0%) than at 15 C (3.1%), indicating closer synchronization between host molting and parasite reproduction at the warmer temperature. At 15 C, the isopods utilized a smaller proportion of the time that was available for brood incubation during the intermolt period of their host. Brood size ranged from 391 to 4,596 young and was positively correlated with parasite and host size. Because development progressed more rapidly

Relative costs of prebasic and prealternate molts for male blue-winged teal

USGS Publications Warehouse

Hohman, W.L.; Manley, S.W.; Richard, D.

1997-01-01

We compared masses of definitive basic and alternate plumages of male Blue-winged Teal (Anas discors) to evaluate the hypothesis that nutritional investments in basic and alternate plumages are related to the duration that plumages are worn and to assess the relative costs of prebasic and prealternate molts. Because these plumages are worn by males for approximately equal durations, we predicted that masses of the basic and alternate body plumages would be similar. To assess nutritional stress (demands greater than available resources) associated with molt, we examined the relation between remigial length and structural size and compared predicted and observed plum-age masses of Blue-winged Teal and other ducks. If birds were nutritionally challenged during remigial molt, then we predicted remigial length would be influenced by nutrition rather than size, and remigial length and size would be unrelated. Alternate body plumage of male Blue-winged Teal weighed about 10% more than the basic body plumage; however, masses of both plumages were less than that predicted on the basis of lean body mass. We argue that deviations between observed and predicted plumage masses were related to factors other than nutrition. Further, remigial lengths were significantly, albeit weakly, related to structural size. We therefore concluded that, although the potential for molt-induced stress may be greatest in small-bodied waterfowl species, there was no clear evidence that molting male Blue-winged Teal were nutritionally stressed. ?? The Cooper Ornithological Society 1997.

Induced molt using cassava meal. 2. Effects on eggshell quality, ultrastructure, and pore density in late-phase laying hens.

PubMed

Gongruttananun, N

2018-03-01

This experiment was conducted to investigate the effect of a non-fasting induced molt using cassava meal on the eggshell quality, ultrastructure, and porosity in late-phase (74 wk old) H&N Brown laying hens. Hens were randomly assigned to 3 treatments of 90 birds each: 1) Controls with no induced molt (CONT); 2) molted by full feeding with cassava meal for 3 wk (FP3); and 3) molted by full feeding with cassava meal for 4 wk (FP4). Following the treatments, groups 2 and 3 were fed a pullet developer diet for 3 weeks. During the molt period, the birds were exposed to an 8L:16D photoperiod and had access to drinking water at all times. Thereafter, all hens were fed a layer diet (17% CP) and exposed to a 16L:8D photoperiod until the end of the study. Compared to the CONT treatment, significant reductions (P < 0.05) in shell weight, thickness, and breaking strength were identified on the sixth d of feeding the molt diet. Significant (P < 0.05) improvements in these parameters were observed for the FP3 and FP4 treatments during the post-molt period, with the greater degree in the FP4 treatment. In addition, scanning electron microscopy revealed a smaller size of mammillary knobs accompanied by a higher density of mammillae in eggs taken from the molted treatments. Evidence of type B mammillae was detected in an egg produced by the CONT hens, whereas confluent and cuffing mammillae were observed in an egg taken from the FP4 birds. Reduced pore densities were found in the molted treatments in some periods of the post-molt production as compared to the CONT treatment. It was concluded that feeding the cassava molt diet for 4 wk could be an effective non-fasting molt method for improving eggshell quality, ultrastructure, and porosity in post-molt laying hens.

The effects of polychlorinated biphenyls (Aroclor 1242) on thyroxine, estradiol, molt, and plumage characteristics in the American kestrel (Falco sparverius)

USGS Publications Warehouse

Quinn, M.J.; French, J.B.; McNabb, F.M.A.; Ottinger, M.A.

2002-01-01

The purpose of this experiment was to determine the effects of Aroclor 1242, a mixture of polychlorinated biphenyls (PCBs), on plumage characteristics and molt in the American kestrel, Falco sparverills. Several characteristics of plumage. including color and molt schedule, are modulated by hormonal signals and hence may be modified by endocrine-active contaminants. If so, the functions of plumage (e.g. communication for mating or territorial defense) may be compromised by exposure to such compounds. Captive American kestrels were fed Aroclor 1242 at 0. 6.0. and 60.0 ppm (n = 6 males and 6 females per treatment) mixed in their normal diet. Concentrations of plasma estradiol and thyroxine were measured weekly from the beginning of treatment. Measured plumage characteristics included width of the black subterminal band on the tail, color (a composite index of hue and saturation), reflectance from 230 to 800 min. pattern of feather loss and regrowth on the tail and wing. and timing of onset and duration of molt. Aroclor 1242 depressed plasma thyroxine. Plasma estradiol levels remained low due to the phase of the breeding cycle. Treatments did not disrupt the measured plumage characteristics. This may be due to timing or dose of exposure or to genetic factors.

Crustacean-derived biomimetic components and nanostructured composites.

PubMed

Grunenfelder, Lessa Kay; Herrera, Steven; Kisailus, David

2014-08-27

Over millions of years, the crustacean exoskeleton has evolved into a rigid, tough, and complex cuticle that is used for structural support, mobility, protection of vital organs, and defense against predation. The crustacean cuticle is characterized by a hierarchically arranged chitin fiber scaffold, mineralized predominately by calcium carbonate and/or calcium phosphate. The structural organization of the mineral and organic within the cuticle occurs over multiple length scales, resulting in a strong and tough biological composite. Here, the ultrastructural details observed in three species of crustacean are reviewed: the American lobster (Homarus americanus), the edible crab (Cancer pagurus), and the peacock mantis shrimp (Odontodactylus scyllarus). The Review concludes with a discussion of recent advances in the development of biomimetics with controlled organic scaffolding, mineralization, and the construction of nanoscale composites, inspired by the organization and formation of the crustacean cuticle. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The current state of knowledge on molt and plumage sequences in selected tropical families: a review

Treesearch

T. B. Ryder; Jared Wolfe

2009-01-01

Annual molts and the subsequent plumages they produce are a ubiquitous element of avian life history. Research pertaining to the utility of molt and plumage has produced a robust framework of age-categorization for the vast majority of temperate avifauna. In comparison to temperate bird species, however, we know very little about resident topical bird molt and plumage...

Occurrence of hemocyanin in ostracod crustaceans.

PubMed

Marxen, Julia C; Pick, Christian; Oakley, Todd H; Burmester, Thorsten

2014-08-01

Hemocyanin is a copper-containing protein that transports O2 in the hemolymph of many arthropod species. Within the crustaceans, hemocyanin appeared to be restricted to Malacostraca but has recently been identified in Remipedia. Here, we report the occurrence of hemocyanin in ostracods, indicating that this respiratory protein is more widespread within crustaceans than previously thought. By analyses of expressed sequence tags and by RT-PCR, we obtained four full length and nine partial hemocyanin sequences from six of ten investigated ostracod species. Hemocyanin was identified in Myodocopida (Actinoseta jonesi, Cypridininae sp., Euphilomedes morini, Skogsbergia lerneri, Vargula tsujii) and Platycopida (Cytherelloidea californica) but not in Podocopida. We found no evidence for the presence of hemoglobin in any of these ostracod species. Like in other arthropods, we identified multiple hemocyanin subunits (up to six) to occur in a single ostracod species. Bayesian phylogenetic analyses showed that ostracod hemocyanin subunit diversity evolved independently from that of other crustaceans. Ostracod hemocyanin subunits were found paraphyletic, with myodocopid and platycopid subunits forming distinct clades within those of the crustaceans. This pattern suggests that ostracod hemocyanins originated from distinct subunits in the pancrustacean stemline.

Molt patterns, age, and sex criteria for selected highland Costa Rican resident landbirds

Treesearch

Jared D. Wolfe; Richard B. Chandler; David I. King

2009-01-01

Demographic studies within temperate latitudes often use molt and plumage-based criteria to differentiate age and sex classes (Bayne & Hobson 2002, Brown et al. 2002, Jones et al. 2004). Despite their critical nature (Pyle et al. 2004, DuVal 2005, Doucet et al. 2007), molt and plumage data derived from resident tropical species remain scarce (Dickey & van...

Notes on winter feeding behavior and molt in Wilson's phalaropes

USGS Publications Warehouse

Burger, J.; Howe, M.

1975-01-01

Wilson's Phalaropes, Steganopus tricolor, migrate in late summer from the prairie regions of North America to their wintering grounds in the highlands of Peru and the inland and coastal waters of Chile, Bolivia, Paraguay, Uruguay, and Argentina (Holmes 1939, Meyer de Schauensee 1970). Reports on these birds from their wintering habitat are few. This paper describes numbers, feeding behavior, and molt of Wilson's Phalaropes wintering in a freshwater marsh in central Argentina. Fieldwork in Argentina was conducted by the senior author. The junior author analyzed molt patterns of birds collected there and added data he collected in North Dakota in 1968 and 1969.

Evaluation of the Bacterial Diversity in Cecal Contents of Laying Hens Fed Various Molting Diets Using Bacterial Tag-Encoded FLX Amplicon Pyrosequencing (bTEFAP)

USDA-ARS?s Scientific Manuscript database

Laying hens are typically induced to molt in order to begin a new egg-laying cycle by withdrawing feed for up to 12-14 d. Fasted hens are more susceptible to colonization and tissue invasion by Salmonella Enteriditis. Much of this increased incidence in fasted hens is thought to be due to changes ...

Abundance and distribution of the common eider in eastern North America during the molting season

USGS Publications Warehouse

Savard, Jean-Pierre L.; Allen, B.; McAuley, D.; Milton, G.R.; Gililand, S.

2005-01-01

Like most other sea ducks, male common eiders (Somateria mollissima) concentrate in large groups to molt following the breeding season. Although Maine conducted surveys in the 1980s, little was known of eider molting sites in Atlantic Canada until recently, when surveys and research conducted in Quebec, Newfoundland, Labrador, Nova Scotia and Maine revealed a number of important molting sites. Sites vary in importance from a few hundred males to tens of thousands. Important sites include the western and southern coastal areas of Anticosti island (40,000 birds), Baie des Milles Vaches (9,000) in Quebec, southwestern Nova Scotia (40,000), Petit Manan Island archipelago (7,000), and Metinic Island archipelago (10,000) in Maine. Molting eider surveys conducted in Maine during the early 1980s and in the St. Lawrence in 2003-2004 revealed large flock sizes, commonly over 2,000 birds, in consistent locations annually. An estimated 40,000 males molt in Nova Scotia and 28,400 in Maine (1981 data). Surveys indicate that important sites are used consistently between years and that local movements occur. Recoveries from banded birds suggest that eiders breeding on the lower North Shore of the St. Lawrence, New Brunswick, Nova Scotia, and even Newfoundland appear to concentrate at the Petit Manan site in Maine. They also suggest inter annual movements between the Nova Scotia and Petit Manan sites. Greater understanding of the relationships between breeding, wintering, and molting sites will facilitate management of this heavily exploited sea duck.

Seasonal changes in concentrations of plasma LH and prolactin associated with the advance in the development of photorefractoriness and molt by high temperature in the starling.

PubMed

Dawson, Alistair; Sharp, Peter J

2010-05-15

In a study on starlings (Sturnus vulgaris) kept on a simulated annual cycle in photoperiod, temperature had no effect on the timing or rate of testicular maturation but high temperature resulted in an advance in the timing of testicular regression and molt (Dawson, 2005). This study asks whether the earlier gonadal regression in response to higher temperature represents a central neuroendocrine response to temperature, and secondly, whether prolactin plays a role in the earlier regression. Castrated starlings were kept on a simulated annual cycle of photoperiod at either 8 or 18 degrees C. Circulating LH and prolactin concentrations were measured and the progress of the post-nuptial molt was recorded as an external indicator of the development of photorefractoriness. Additionally plasma prolactin was measured in samples taken from intact male and female starlings in the 2005 study. In castrated birds, LH concentrations decreased three weeks earlier at 18 degrees C. These birds also showed the same three week advance in molt as males and females in the earlier study. This demonstrates that the advance in regression caused by higher temperatures probably results from a central neuroendocrine mechanism, i.e., an advance in photorefractoriness, rather than an effect at the level of the gonads. Temperature had a highly significant effect on the changes in prolactin - peak prolactin occurred three weeks earlier at 18 degrees C. However, there was no clear consistent significant difference in prolactin between the two temperatures in advance of the onset of photorefractoriness, so the advance in photorefractoriness may not be mediated by prolactin. The higher temperature resulted in a significantly earlier decrease in prolactin and this may be causally related to the advance in molt. Copyright 2010 Elsevier Inc. All rights reserved.

50 CFR 17.46 - Special rules-crustaceans.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 2 2013-10-01 2013-10-01 false Special rules-crustaceans. 17.46 Section 17.46 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Special rules—crustaceans. (a) Madison Cave isopod (Antrolana lira). (1) All provisions of § 17.31 (a) and...

50 CFR 17.46 - Special rules-crustaceans.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 2 2011-10-01 2011-10-01 false Special rules-crustaceans. 17.46 Section 17.46 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Special rules—crustaceans. (a) Madison Cave isopod (Antrolana lira). (1) All provisions of § 17.31 (a) and...

50 CFR 17.46 - Special rules-crustaceans.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 2 2012-10-01 2012-10-01 false Special rules-crustaceans. 17.46 Section 17.46 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Special rules—crustaceans. (a) Madison Cave isopod (Antrolana lira). (1) All provisions of § 17.31 (a) and...

50 CFR 17.46 - Special rules-crustaceans.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 2 2014-10-01 2014-10-01 false Special rules-crustaceans. 17.46 Section 17.46 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Special rules—crustaceans. (a) Madison Cave isopod (Antrolana lira). (1) All provisions of § 17.31 (a) and...

50 CFR 17.46 - Special rules-crustaceans.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 2 2010-10-01 2010-10-01 false Special rules-crustaceans. 17.46 Section 17.46 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Special rules—crustaceans. (a) Madison Cave isopod (Antrolana lira). (1) All provisions of § 17.31 (a) and...

Mechanistic mathematical modelling of mercaptopurine effects on cell cycle of human acute lymphoblastic leukaemia cells

PubMed Central

Panetta, J C; Evans, W E; Cheok, M H

2006-01-01

The antimetabolite mercaptopurine (MP) is widely used to treat childhood acute lymphoblastic leukaemia (ALL). To study the dynamics of MP on the cell cycle, we incubated human T-cell leukaemia cell lines (Molt-4 sensitive and resistant subline and P12 resistant) with 10 μM MP and measured total cell count, cell cycle distribution, percent viable, percent apoptotic, and percent dead cells serially over 72 h. We developed a mathematical model of the cell cycle dynamics after treatment with MP and used it to show that the Molt-4 sensitive controls had a significantly higher rate of cells entering apoptosis (2.7-fold, P<0.00001) relative to the resistant cell lines. Additionally, when treated with MP, the sensitive cell line showed a significant increase in the rate at which cells enter apoptosis compared to its controls (2.4-fold, P<0.00001). Of note, the resistant cell lines had a higher rate of antimetabolite incorporation into the DNA of viable cells (>1.4-fold, P<0.01). Lastly, in contrast to the other cell lines, the Molt-4 resistant subline continued to cycle, though at a rate slower relative to its control, rather than proceed to apoptosis. This led to a larger S-phase block in the Molt-4 resistant cell line, but not a higher rate of cell death. Gene expression of apoptosis, cell cycle, and repair genes were consistent with mechanistic dynamics described by the model. In summary, the mathematical model provides a quantitative assessment to compare the cell cycle effects of MP in cells with varying degrees of MP resistance. PMID:16333308

High fidelity does not preclude colonization: range expansion of molting Black Brant on the Arctic coast of Alaska

USGS Publications Warehouse

Flint, Paul L.; Meixell, Brandt W.; Mallek, Edward J.

2014-01-01

High rates of site fidelity have been assumed to infer static distributions of molting geese in some cases. To test this assumption, we examined movements of individually marked birds to understand the underlying mechanisms of range expansion of molting Black Brant (Branta bernicla nigricans) on the Arctic Coastal Plain (ACP) of Alaska. The Teshekpuk Lake Special Area (TLSA) on the ACP was created to protect the primary molting area of Brant. When established in 1977, the TLSA was thought to include most, if not all, wetlands used by molting Brant on the ACP. From 2010 to 2013, we surveyed areas outside the TLSA and counted an average of 9800 Brant per year, representing 29–37% of all molting Brant counted on the ACP. We captured and banded molting Brant in 2011 and 2012 both within the TLSA and outside the TLSA at the Piasuk River Delta and Cape Simpson to assess movements of birds among areas across years. Estimates of movement rates out of the TLSA exceeded those into the TLSA, demonstrating overall directional dispersal. We found differences in sex and age ratios and proportions of adult females with brood patches, but no differences in mass dynamics for birds captured within and outside the TLSA. Overall fidelity rates to specific lakes (0.81, range = 0.49–0.92) were unchanged from comparable estimates obtained in the early 1990s. We conclude that Brant are dispersing from the TLSA into new molting areas while simultaneously redistributing within the TLSA, likely as a consequence of changes in relative habitat quality. Shifts in distribution resulted from colonization of new areas by young birds as well as low levels of directional dispersal of birds that previously molted in the TLSA. Based on combined counts, the overall number of molting Brant across the ACP has increased substantially.

Nutrient intake determines post-maturity molting in the golden orb-web spider Nephila pilipes (Araneae: Araneidae).

PubMed

Cheng, Ren-Chung; Zhang, Shichang; Chen, Yu-Chun; Lee, Chia-Yi; Chou, Yi-Ling; Ye, Hui-Ying; Piorkowski, Dakota; Liao, Chen-Pan; Tso, I-Min

2017-06-15

While molting occurs in the development of many animals, especially arthropods, post-maturity molting (PMM, organisms continue to molt after sexual maturity) has received little attention. The mechanism of molting has been studied intensively; however, the mechanism of PMM remains unknown although it is suggested to be crucial for the development of body size. In this study, we investigated factors that potentially induce PMM in the golden orb-web spider Nephila pilipes , which has the greatest degree of sexual dimorphism among terrestrial animals. We manipulated the mating history and the nutrient consumption of the females to examine whether they affect PMM. The results showed that female spiders under low nutrition were more likely to molt as adults, and mating had no significant influence on the occurrence of PMM. Moreover, spiders that underwent PMM lived longer than those that did not and their body sizes were significantly increased. Therefore, we concluded that nutritional condition rather than mating history affect PMM. © 2017. Published by The Company of Biologists Ltd.

Changes in intracellular calcium concentration in crustacean (Callinectes sapidus) Y-organs: relation to the hemolymphatic ecdysteroid titer.

PubMed

Chen, Hsiang-Yin; Watson, R Douglas

2011-01-01

Secretion of ecdysteroid molting hormones by crustacean Y-organs is negatively regulated (inhibited) by molt-inhibiting hormone (MIH), a neuropeptide produced by neurosecretory cells in eyestalk ganglia. The inhibitory effect of MIH is mediated by one or more cyclic nucleotide second messengers. In addition, available data indicate that ecdysteroidogenesis is positively regulated (stimulated) by intracellular calcium. However, despite the apparent critical role of calcium in regulating ecdysteroidogenesis, the level of Ca(2+) in Y-organs cells has not been previously determined. In studies reported here, eyestalks were ablated from blue crabs (Callinectes sapidus) to remove the endogenous source of MIH and activate Y-organs. At 0, 3, 6, and 9 days after eyestalk ablation (D0, D3, D6, and D9, respectively), the level of Ca(2+) in Y-organ cells was determined using a fluorescent calcium indicator (Fluo-4), and the hemolymphatic ecdysteroid titer was determined by radioimmunoassay. Calcium fluorescence in D6 Y-organs was 3.5-fold higher than that in D0 controls; calcium fluorescence in D9 Y-organs was 3.9-fold higher than in D0 controls (P<0.05). Measurement of fluorescence along a transect drawn through representative cells indicated that the calcium fluorescence was localized to cytoplasm and not to nuclei. Associated with the increase in intracellular Ca(2+) was a significant increase in the hemolymphatic ecdysteroid titer: The level of ecdysteroids in hemolymph rose from 5.5 ng/mL on D0 to 49.6 ng/mL on D6 and 87.2 ng/mL on D9 (P<0.05). The results are consistent with the hypothesis that ecdysteroidogenesis is stimulated by an increase in intracellular Ca(2+).

VITELLOGENISIS AND IT'S ENDOCRINE CONTROL IN DECAPOD CRUSTACEANS

EPA Science Inventory

Vitellogenesis, the production of vitellin (major yolk protein), is controlled in decapod crustaceans by several hormones. With increasing efforts world-wide to successfully culture economically important crustaceans, such as shrimp, there is growing interest in attaining a bette...

50 CFR 665.240 - Hawaii crustacean fisheries. [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Hawaii crustacean fisheries. [Reserved] 665.240 Section 665.240 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC... Hawaii Fisheries § 665.240 Hawaii crustacean fisheries. [Reserved] ...

50 CFR 665.240 - Hawaii crustacean fisheries. [Reserved

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Hawaii crustacean fisheries. [Reserved] 665.240 Section 665.240 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC... Hawaii Fisheries § 665.240 Hawaii crustacean fisheries. [Reserved] ...

50 CFR 665.240 - Hawaii crustacean fisheries. [Reserved

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Hawaii crustacean fisheries. [Reserved] 665.240 Section 665.240 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC... Hawaii Fisheries § 665.240 Hawaii crustacean fisheries. [Reserved] ...

50 CFR 665.240 - Hawaii crustacean fisheries. [Reserved

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Hawaii crustacean fisheries. [Reserved] 665.240 Section 665.240 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC... Hawaii Fisheries § 665.240 Hawaii crustacean fisheries. [Reserved] ...

50 CFR 665.440 - Mariana crustacean fisheries. [Reserved

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Mariana crustacean fisheries. [Reserved] 665.440 Section 665.440 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC... Mariana Archipelago Fisheries § 665.440 Mariana crustacean fisheries. [Reserved] ...

50 CFR 665.440 - Mariana crustacean fisheries. [Reserved

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Mariana crustacean fisheries. [Reserved] 665.440 Section 665.440 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC... Mariana Archipelago Fisheries § 665.440 Mariana crustacean fisheries. [Reserved] ...

50 CFR 665.440 - Mariana crustacean fisheries. [Reserved

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Mariana crustacean fisheries. [Reserved] 665.440 Section 665.440 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC... Mariana Archipelago Fisheries § 665.440 Mariana crustacean fisheries. [Reserved] ...

50 CFR 665.640 - PRIA crustacean fisheries. [Reserved

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false PRIA crustacean fisheries. [Reserved] 665.640 Section 665.640 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Island Area Fisheries § 665.640 PRIA crustacean fisheries. [Reserved] ...

50 CFR 665.640 - PRIA crustacean fisheries. [Reserved

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false PRIA crustacean fisheries. [Reserved] 665.640 Section 665.640 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Island Area Fisheries § 665.640 PRIA crustacean fisheries. [Reserved] ...

50 CFR 665.640 - PRIA crustacean fisheries. [Reserved

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false PRIA crustacean fisheries. [Reserved] 665.640 Section 665.640 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Island Area Fisheries § 665.640 PRIA crustacean fisheries. [Reserved] ...

Molt-associated changes in hematologic and plasma biochemical values and stress hormone levels in African penguins (Spheniscus demersus).

PubMed

Mazzaro, Lisa M; Meegan, Jenny; Sarran, Delphine; Romano, Tracy A; Bonato, Vinicius; Deng, Shibing; Dunn, J Lawrence

2013-12-01

Handling, including blood collection, has often been discouraged in molting penguins because it is considered an additional stress imposed on birds already experiencing major physiologic stress associated with molting. To evaluate the degree of physiologic stress posed by molting, we compared the hematologic and plasma biochemical values and hormone levels of molting and nonmolting African penguins, Spheniscus demersus. Five male and 5 female penguins randomly chosen were given complete physical examinations, were weighed, and blood samples were taken at 7 time points before, during, and after the molt. Data were analyzed by linear mixed-model analysis of variance. Throughout the study, behavior and appetite remained normal. Catecholamine levels were highly variable within and among subjects, whereas mean corticosterone levels were significantly different between baseline, molt, and postmolt values. Significant differences from baseline values were observed in many of the hematologic analytes; however, only decreases in hematocrit and red blood cell count values were considered clinically significant. Anemia due to experimentally induced blood loss as a possible cause of the significant hematologic changes was ruled out based on results of a follow-up control study during the nonmolt season, which showed no significant changes in hematocrit level or total red blood cell counts when using similar sampling protocols, which indicates that these changes were associated with molt.

Effects of Organotins on Crustaceans: Update and Perspectives

PubMed Central

Vogt, Éverton L.; Model, Jorge F. A.; Vinagre, Anapaula S.

2018-01-01

Organotins (OTs) are considered some of the most toxic chemicals introduced into aquatic environments by anthropogenic activities. They are widely used for agricultural and industrial purposes and as antifouling additives on boat hull’s paints. Even though the use of OTs was banned in 2008, elevated levels of OTs can still be detected in aquatic environments. OTs’ deleterious effects upon wildlife and experimental animals are well documented and include endocrine disruption, immunotoxicity, neurotoxicity, genotoxicity, and metabolic dysfunction. Crustaceans are key members of zooplankton and benthic communities and have vital roles in food chains, so the endocrine-disrupting effects of tributyltin (TBT) on crustaceans can affect other organisms. TBT can disrupt carbohydrate and lipid homeostasis of crustaceans by interacting with retinoid X receptor (RXR) and crustacean hyperglycemic hormone (CHH) signaling. Moreover, it can also interact with other nuclear receptors, disrupting methyl farnesoate and ecdysteroid signaling, thereby altering growth and sexual maturity, respectively. This compound also interferes in cytochrome P450 system disrupting steroid synthesis and reproduction. Crustaceans are also important fisheries worldwide, and its consumption can pose risks to human health. However, some questions remain unanswered. This mini review aims to update information about the effects of OTs on the metabolism, growth, and reproduction of crustaceans; to compare with known effects in mammals; and to point aspects that still needs to be addressed in future studies. Since both macrocrustaceans and microcrustaceans are good models to study the effects of sublethal TBT contamination, novel studies should be developed using multibiomarkers and omics technology. PMID:29535684

Effects of a premolt calcium and low-energy molt program on laying hen behavior and heterophil-to-lymphocyte ratios.

PubMed

Dickey, E R; Bregendahl, K; Stalder, K; Fitzgerald, R; Johnson, A K

2010-11-01

The objectives of this study were to compare the behaviors, postures, and heterophil-to-lymphocyte ratios (H:L) of laying hens housed in a cage system when offered a Ca premolt treatment and low-energy molt diets vs. a traditional feed withdrawal (FW) treatment during and after molt. A total of 144 Hy-Line W-36 hens (85 wk of age), housed 3 hens/cage (413 cm(2)/hen), were used. Hens were allotted to treatments according to a randomized complete block design, with the cage location and initial BW as the blocking criteria. Six treatments were compared in a 2 × 3 factorial arrangement with 2 Ca premolt treatments (fine or coarse) and 3 low-energy molt diets (FW, soybean hulls, or wheat middlings). The 2 Ca premolt treatments differed only in Ca particle size (fine was 0.14 mm and coarse was 2.27 mm mean diameter). Two postures and 5 behaviors were recorded and H:L was measured. Data were analyzed using the MIXED procedure of SAS, with P < 0.05 considered significant. There were no differences in behaviors, postures, or H:L during the premolt baseline period. The Ca premolt treatment had no carryover effects during or after molt for behaviors or postures. During molt, hens in the FW treatment were more active, and they ate and drank less compared with hens fed soybean hulls or wheat middlings, but there were no differences in aggression, nonnutritive pecking, or sitting. Drinking and aggression during and after molt were not different, but hens postmolt engaged in more sitting and feeding and less activity, nonnutritive pecking, and preening compared with during molt. There were no differences in H:L during or after molt. In conclusion, a Ca premolt treatment did not affect the behavior of the laying hen. The low-energy molt diets did not adversely affect behavior compared with FW and did not increase H:L; therefore, they could be useful alternatives for inducing molt in laying hens.

Ecdysone receptor agonism leading to lethal molting disruption in arthropods: Review and adverse outcome pathway development

EPA Science Inventory

Molting is a key biological process in growth, development, reproduction and survival in arthropods. Complex neuroendocrine pathways are involved in the regulation of molting and may potentially become targets of environmental endocrine disrupting compounds (EDCs). For example, s...

The eyes have it: A brief history of crustacean neuroendocrinology.

PubMed

Hopkins, Penny M

2012-02-01

To help celebrate the 50th anniversary of General and Comparative Endocrinology, the history of only a small portion of crustacean endocrinology is presented here. The field of crustacean endocrinology dates back to the decades prior to the establishment of General and Comparative Endocrinology and the first article about crustacean endocrinology published in this journal was concerned with the anatomy of neurosecretory and neurohemal structures in brachyuran crabs. This review looks at the history of neuroendocrinology in crustaceans during that time and tries to put perspective on the future of this field. Copyright © 2011 Elsevier Inc. All rights reserved.

Houttuynia cordata Thunb fraction induces human leukemic Molt-4 cell apoptosis through the endoplasmic reticulum stress pathway.

PubMed

Prommaban, Adchara; Kodchakorn, Kanchanok; Kongtawelert, Prachya; Banjerdpongchai, Ratana

2012-01-01

Houttuynia cordata Thunb (HCT) is a native herb found in Southeast Asia which features various pharmacological activities against allergy, inflammation, viral and bacterial infection, and cancer. The aims of this study were to determine the cytotoxic effect of 6 fractions obtained from silica gel column chromatography of alcoholic HCT extract on human leukemic Molt-4 cells and demonstrate mechanisms of cell death. Six HCT fractions were cytotoxic to human lymphoblastic leukemic Molt-4 cells in a dose-dependent manner by MTT assay, fraction 4 exerting the greatest effects. Treatment with IC50 of HCT fraction 4 significantly induced Molt-4 apoptosis detected by annexinV-FITC/propidium iodide for externalization of phosphatidylserine to the outer layer of cell membrane. The mitochondrial transmembrane potential was reduced in HCT fraction 4-treated Molt-4 cells. Moreover, decreased expression of Bcl-xl and increased levels of Smac/Diablo, Bax and GRP78 proteins were noted on immunoblotting. In conclusion, HCT fraction 4 induces Molt-4 apoptosis cell through an endoplasmic reticulum stress pathway.

California condor plumage and molt as field study aids

USGS Publications Warehouse

Wilbur, S.R.

1975-01-01

An analysis is made of the reliability of plumage and molt characteristics of the California condor for estimating age and identifying individual birds. Neither character seems sufficiently reliable to use in more than a general way.

Transcriptomic analysis of the autophagy machinery in crustaceans.

PubMed

Suwansa-Ard, Saowaros; Kankuan, Wilairat; Thongbuakaew, Tipsuda; Saetan, Jirawat; Kornthong, Napamanee; Kruangkum, Thanapong; Khornchatri, Kanjana; Cummins, Scott F; Isidoro, Ciro; Sobhon, Prasert

2016-08-09

The giant freshwater prawn, Macrobrachium rosenbergii, is a decapod crustacean that is commercially important as a food source. Farming of commercial crustaceans requires an efficient management strategy because the animals are easily subjected to stress and diseases during the culture. Autophagy, a stress response process, is well-documented and conserved in most animals, yet it is poorly studied in crustaceans. In this study, we have performed an in silico search for transcripts encoding autophagy-related (Atg) proteins within various tissue transcriptomes of M. rosenbergii. Basic Local Alignment Search Tool (BLAST) search using previously known Atg proteins as queries revealed 41 transcripts encoding homologous M. rosenbergii Atg proteins. Among these Atg proteins, we selected commonly used autophagy markers, including Beclin 1, vacuolar protein sorting (Vps) 34, microtubule-associated proteins 1A/1B light chain 3B (MAP1LC3B), p62/sequestosome 1 (SQSTM1), and lysosomal-associated membrane protein 1 (Lamp-1) for further sequence analyses using comparative alignment and protein structural prediction. We found that crustacean autophagy marker proteins contain conserved motifs typical of other animal Atg proteins. Western blotting using commercial antibodies raised against human Atg marker proteins indicated their presence in various M. rosenbergii tissues, while immunohistochemistry localized Atg marker proteins within ovarian tissue, specifically late stage oocytes. This study demonstrates that the molecular components of autophagic process are conserved in crustaceans, which is comparable to autophagic process in mammals. Furthermore, it provides a foundation for further studies of autophagy in crustaceans that may lead to more understanding of the reproduction- and stress-related autophagy, which will enable the efficient aquaculture practices.

Midgut epithelium in molting silkworm: A fine balance among cell growth, differentiation, and survival.

PubMed

Franzetti, Eleonora; Casartelli, Morena; D'Antona, Paola; Montali, Aurora; Romanelli, Davide; Cappellozza, Silvia; Caccia, Silvia; Grimaldi, Annalisa; de Eguileor, Magda; Tettamanti, Gianluca

2016-07-01

The midgut of insects has attracted great attention as a system for studying intestinal stem cells (ISCs) as well as cell death-related processes, such as apoptosis and autophagy. Among insects, Lepidoptera represent a good model to analyze these cells and processes. In particular, larva-larva molting is an interesting developmental phase since the larva must deal with nutrient starvation and its organs are subjected to rearrangements due to proliferation and differentiation events. Several studies have analyzed ISCs in vitro and characterized key factors involved in their division and differentiation during molt. However, in vivo studies performed during larva-larva transition on these cells, and on the whole midgut epithelium, are fragmentary. In the present study, we analyzed the larval midgut epithelium of the silkworm, Bombyx mori, during larva-larva molting, focusing our attention on ISCs. Moreover, we investigated the metabolic changes that occur in the epithelium and evaluated the intervention of autophagy. Our data on ISCs proliferation and differentiation, autophagy activation, and metabolic and functional activities of the midgut cells shed light on the complexity of this organ during the molting phase. Copyright © 2016 Elsevier Ltd. All rights reserved.

Plumage development and molt in Long-tailed Manakins (Chiroxiphia linearis): Variation according to sex and age

USGS Publications Warehouse

Doucet, S.M.; McDonald, D.B.; Foster, M.S.; Clay, R.P.

2007-01-01

Lek-mating Long-tailed Manakins (Chiroxiphia linearis) exhibit an unusual pattern of delayed plumage maturation. Each year, males progress through a series of predefinitive plumages before attaining definitive plumage in their fifth calendar year. Females also exhibit variation in plumage coloration, with some females displaying male-like plumage characteristics. Using data from mist-net captures in northwest Costa Rica (n = 1,315) and museum specimens from throughout the range of Long-tailed Manakins (n = 585), we documented the plumage sequence progression of males, explored variation in female plumage, and described the timing of molt in this species. Males progressed through a series of age-specific predefinitive plumages, which enabled the accurate aging of predefinitive-plumaged males in the field; this predefinitive plumage sequence is the basis for age-related status-signaling in these males. Females tended to acquire red coloration in the crown as they aged. However, colorful plumage in females may be a byproduct of selection on bright male plumage. Females exhibited an early peak of molt activity from February to April, little molt from May through July, and a second, more pronounced peak of molt activity in October. By contrast, males in older predefinitive-plumage stages and males in definitive plumage exhibited comparable unimodal distributions in molt activity beginning in June and peaking between July and October. Our data are consistent with selective pressure to avoid the costs of molt-breeding overlap in females and older males. Our findings have important implications for social organization and signaling in Long- tailed Manakins, and for the evolution of delayed plumage maturation in birds.

The Salmon Louse Lepeophtheirus salmonis (Copepoda: Caligidae) Life Cycle Has Only Two Chalimus Stages

PubMed Central

Dalvin, Sussie T.; Bron, James E.; Nilsen, Frank; Boxshall, Geoff; Skern-Mauritzen, Rasmus

2013-01-01

Each year the salmon louse ( Lepeophtheirus salmonis Krøyer, 1838) causes multi-million dollar commercial losses to the salmon farming industry world-wide, and strict lice control regimes have been put in place to reduce the release of salmon louse larvae from aquaculture facilities into the environment. For half a century, the Lepeophtheirus life cycle has been regarded as the only copepod life cycle including 8 post-nauplius instars as confirmed in four different species, including L . salmonis . Here we prove that the accepted life cycle of the salmon louse is wrong. By observations of chalimus larvae molting in incubators and by morphometric cluster analysis, we show that there are only two chalimus instars: chalimus 1 (comprising the former chalimus I and II stages which are not separated by a molt) and chalimus 2 (the former chalimus III and IV stages which are not separated by a molt). Consequently the salmon louse life cycle has only six post-nauplius instars, as in other genera of caligid sea lice and copepods in general. These findings are of fundamental importance in experimental studies as well as for interpretation of salmon louse biology and for control and management of this economically important parasite. PMID:24069203

Crustacean Larvae-Vision in the Plankton.

PubMed

Cronin, Thomas W; Bok, Michael J; Lin, Chan

2017-11-01

We review the visual systems of crustacean larvae, concentrating on the compound eyes of decapod and stomatopod larvae as well as the functional and behavioral aspects of their vision. Larval compound eyes of these macrurans are all built on fundamentally the same optical plan, the transparent apposition eye, which is eminently suitable for modification into the abundantly diverse optical systems of the adults. Many of these eyes contain a layer of reflective structures overlying the retina that produces a counterilluminating eyeshine, so they are unique in being camouflaged both by their transparency and by their reflection of light spectrally similar to background light to conceal the opaque retina. Besides the pair of compound eyes, at least some crustacean larvae have a non-imaging photoreceptor system based on a naupliar eye and possibly other frontal eyes. Larval compound-eye photoreceptors send axons to a large and well-developed optic lobe consisting of a series of neuropils that are similar to those of adult crustaceans and insects, implying sophisticated analysis of visual stimuli. The visual system fosters a number of advanced and flexible behaviors that permit crustacean larvae to survive extended periods in the plankton and allows them to reach acceptable adult habitats, within which to metamorphose. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

NHR-23 dependent collagen and hedgehog-related genes required for molting

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

Kouns, Nathaniel A.; Nakielna, Johana; Behensky, Frantisek

2011-10-07

Highlights: {yields} NHR-23 is a critical regulator of nematode development and molting. {yields} The manuscript characterizes the loss-of-function phenotype of an nhr-23 mutant. {yields} Whole genome expression analysis identifies new potential targets of NHR-23. {yields} Hedgehog-related genes are identified as NHR-23 dependent genes. {yields} New link between sterol mediated signaling and regulation by NHR-23 is found. -- Abstract: NHR-23, a conserved member of the nuclear receptor family of transcription factors, is required for normal development in Caenorhabditis elegans where it plays a critical role in growth and molting. In a search for NHR-23 dependent genes, we performed whole genome comparativemore » expression microarrays on both control and nhr-23 inhibited synchronized larvae. Genes that decreased in response to nhr-23 RNAi included several collagen genes. Unexpectedly, several hedgehog-related genes were also down-regulated after nhr-23 RNAi. A homozygous nhr-23 deletion allele was used to confirm the RNAi knockdown phenotypes and the changes in gene expression. Our results indicate that NHR-23 is a critical co-regulator of functionally linked genes involved in growth and molting and reveal evolutionary parallels among the ecdysozoa.« less

The relationship between circulating ecdysteroids and chela allometry in male tanner crabs: Evidence for a terminal molt in the genus Chionoecetes

USGS Publications Warehouse

Tamone, S.L.; Taggart, S. James; Andrews, A.G.; Mondragon, Jennifer; Nielsen, J.K.

2007-01-01

Whether male Tanner crabs, Chionoecetes bairdi, undergo a terminal molt associated with a change in claw allometry has long been debated. We measured molting hormone levels in captured male C. bairdi to assess the potential for molting. We plotted a frequency histogram of chela height to carapace width ratios and found a bimodal distribution of crabs with a ratio of approximately 0.18 separating the two modes. Male crabs with a ratio less than 0.18 were classified as "small-clawed" (SC) while crabs with a ratio greater than 0.18 were classified as "large-clawed" (LC). Circulating molting hormones between SC and LC crabs were compared. Significantly lower ecdysteroid levels were found in LC crabs, indicating that this morphotype had negligible potential for molting. Circulating ecdysteroids were measured in SC males of different shell conditions (soft, new, old, and very old) and no significant differences were found. This research suggests that the molt to LC morphology is a terminal molt. The results from this study have important implications for fisheries management because sub-legal LC males will not recruit into the fishery and removal of larger males may have long term effects on population size structure.

Effects of polystyrene microbeads in marine planktonic crustaceans.

PubMed

Gambardella, Chiara; Morgana, Silvia; Ferrando, Sara; Bramini, Mattia; Piazza, Veronica; Costa, Elisa; Garaventa, Francesca; Faimali, Marco

2017-11-01

Plastic debris accumulates in the marine environment, fragmenting into microplastics (MP), causing concern about their potential toxic effects when ingested by marine organisms. The aim of this study was to verify whether 0.1µm polystyrene beads are likely to trigger lethal and sub-lethal responses in marine planktonic crustaceans. MP build-up, mortality, swimming speed alteration and enzyme activity (cholinesterases, catalase) were investigated in the larval stages of Amphibalanus amphitrite barnacle and of Artemia franciscana brine shrimp exposed to a wide range of MP concentrations (from 0.001 to 10mgL -1 ) for 24 and 48h. The results show that MP were accumulated in crustaceans, without affecting mortality. Swimming activity was significantly altered in crustaceans exposed to high MP concentrations (> 1mgL -1 ) after 48h. Enzyme activities were significantly affected in all organisms exposed to all the above MP concentrations, indicating that neurotoxic effects and oxidative stress were induced after MP treatment. These findings provide new insight into sub-lethal MP effects on marine crustaceans. Copyright © 2017 Elsevier Inc. All rights reserved.

The crustaceans and pycnogonids of the Mariana Islands

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

Paulay, Gustav; Kropp, Roy K.; Ng, Peter K.

2003-09-01

The crustacean and pycnogonid fauna of the Mariana Islands is reviewed, and 829 crustacean and 15 pycnogonid species are documented from the archipelago based on literature records and new collections, including 272 new records. Voucher specimens are listed for 605 and photographic records for 356 species. The bulk of the fauna is marine, including 12 terrestrial and 11 freshwater decapods with marine larvae. Five cladocerans comprise the known freshwater fauna, and 25 peracarids and one copepod are currently documented on land. Coverage reflects a taxonomically uneven effort, and is strongly biased toward macrocrustaceans, with decapods accounting for 80%, and crabsmore » for 50% of the recorded crustacean diversity.« less

Biological effects of the anti-parasitic chemotherapeutant emamectin benzoate on a non-target crustacean, the spot prawn (Pandalus platyceros Brandt, 1851) under laboratory conditions.

PubMed

Veldhoen, Nik; Ikonomou, Michael G; Buday, Craig; Jordan, Jameson; Rehaume, Vicki; Cabecinha, Melissa; Dubetz, Cory; Chamberlain, Jon; Pittroff, Sabrina; Vallée, Kurtis; van Aggelen, Graham; Helbing, Caren C

2012-02-01

The potential impact of commercial salmon aquaculture along the coast of British Columbia on the health of non-target marine wildlife is of growing concern. In the current initiative, the biological effects on gene expression within spot prawn (Pandalus platyceros) exposed to the sea lice controlling agent, emamectin benzoate (EB; 0.1-4.8 mg/kg sediment), were investigated. A mean sediment/water partitioning coefficient (K(p)) was determined to be 21.81 and significant levels of EB were detected in the tail muscle tissue in all exposed animals. Animals selected for the experiment did not have eggs and were of similar weight. Significant mortality was observed within 8 days of EB treatment at concentrations between 0.1 and 0.8 mg/kg and there was no effect of EB on molting. Twelve spot prawn cDNA sequences were isolated from the tail muscle either by directed cloning or subtractive hybridization of control versus EB exposed tissues. Three of the transcripts most affected by EB exposure matched sequences encoding the 60S ribosomal protein L22, spliceosome RNA helicase WM6/UAP56, and the intracellular signal mediator histidine triad nucleotide binding protein 1 suggesting that translation, transcription regulation, and apoptosis pathways were impacted. The mRNA encoding the molting enzyme, β-N-acetylglucosaminidase, was not affected by EB treatment. However, the expression of this transcript was extremely variable making it unsuitable for effects assessment. The results suggest that short-term exposure to EB can impact biological processes within this non-target crustacean. Copyright © 2011 Elsevier B.V. All rights reserved.

Molting site fidelity accounts for colony elimination of the Formosan subterranean termites (Isoptera: Rhinotermitidae) by chitin synthesis inhibitor baits.

PubMed

Kakkar, G; Osbrink, W; Su, N-Y

2018-01-19

Site fidelity by molting termites in Formosan subterranean termite, Coptotermes formosanus Shiraki colonies is a new addition to our understanding of lower termites' behavior and biology. Our previous studies indicated that workers moved to the central nest to molt in the presence of eggs and reproductives. The current study showed that noviflumuron-affected workers also return to the central nest and died in the vicinity of reproductives and eggs. The aversion to the dead and decaying workers caused reproductives and brood to leave the original central nest site in a colony and refuge at newer sites every few days in response to newly dead workers near them. Because mortality was an event observed only in workers undergoing molting under the effect of noviflumuron- a CSI, the death of molting individuals was observed only around reproductives and brood. This study reveals a previously undiscovered behavior of molting termites and the mechanics behind a successful arsenal; noviflumuron baits used against subterranean termites.

50 CFR 665.140 - American Samoa Crustacean Fisheries. [Reserved

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false American Samoa Crustacean Fisheries. [Reserved] 665.140 Section 665.140 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... PACIFIC American Samoa Fisheries § 665.140 American Samoa Crustacean Fisheries. [Reserved] ...

50 CFR 665.140 - American Samoa Crustacean Fisheries. [Reserved

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false American Samoa Crustacean Fisheries. [Reserved] 665.140 Section 665.140 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... PACIFIC American Samoa Fisheries § 665.140 American Samoa Crustacean Fisheries. [Reserved] ...

50 CFR 665.140 - American Samoa Crustacean Fisheries. [Reserved

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false American Samoa Crustacean Fisheries. [Reserved] 665.140 Section 665.140 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... PACIFIC American Samoa Fisheries § 665.140 American Samoa Crustacean Fisheries. [Reserved] ...

Transcriptomic, cellular and life-history responses of Daphnia magna chronically exposed to benzotriazoles: Endocrine-disrupting potential and molting effects

PubMed Central

Giraudo, Maeva; Douville, Mélanie; Cottin, Guillaume; Houde, Magali

2017-01-01

Benzotriazoles (BZTs) are ubiquitous aquatic contaminants used in a wide range of industrial and domestic applications from aircraft deicers to dishwasher tablets. Acute toxicity has been reported in aquatic organisms for some of the BZTs but their mode of action remains unknown. The objectives of this study were to evaluate the transcriptomic response of D. magna exposed to sublethal doses of 1H-benzotriazole (BTR), 5-methyl-1H-benzotriazole (5MeBTR) and 5-chloro-1H-benzotriazole (5ClBTR) using RNA-sequencing and quantitative real-time PCR. Cellular and life-history endpoints (survival, number of neonates, growth) were also investigated. Significant effects on the molting frequency were observed after 21-d exposure to 5MeBTR and 5ClBTR. No effects on molting frequency were observed for BTR but RNA-seq results indicated that this BZT induced the up-regulation of genes coding for cuticular proteins, which could have compensated the molting disruption. Molting in cladocerans is actively controlled by ecdysteroid hormones. Complementary short-term temporal analysis (4- and 8-d exposure) of the transcription of genes related to molting and hormone-mediated processes indicated that the three compounds had specific modes of action. BTR induced the transcription of genes involved in 20-hydroxyecdysone synthesis, which suggests pro-ecdysteroid properties. 5ClBTR exposure induced protein activity and transcriptional levels of chitinase enzymes, associated with an impact on ecdysteroid signaling pathways, which could explain the decrease in molt frequency. Finally, 5MeBTR seemed to increase molt frequency through epigenetic processes. Overall, results suggested that molting effects observed at the physiological level could be linked to endocrine regulation impacts of BZTs at the molecular level. PMID:28196088

Hox genes and study of Hox genes in crustacean

NASA Astrophysics Data System (ADS)

Hou, Lin; Chen, Zhijuan; Xu, Mingyu; Lin, Shengguo; Wang, Lu

2004-12-01

Homeobox genes have been discovered in many species. These genes are known to play a major role in specifying regional identity along the anterior-posterior axis of animals from a wide range of phyla. The products of the homeotic genes are a set of evolutionarily conserved transcription factors that control elaborate developmental processes and specify cell fates in metazoans. Crustacean, presenting a variety of body plans not encountered in any other class or phylum of the Metazoa, has been shown to possess a single set of homologous Hox genes like insect. The ancestral crustacean Hox gene complex comprised ten genes: eight homologous to the hometic Hox genes and two related to nonhomeotic genes presented within the insect Hox complexes. The crustacean in particular exhibits an abundant diversity segment specialization and tagmosis. This morphological diversity relates to the Hox genes. In crustacean body plan, different Hox genes control different segments and tagmosis.

Significant fluctuations in ecdysteroid receptor gene (EcR) expression in relation to seasons of molt and reproduction in the grapsid crab, Metopograpsus messor (Brachyura: Decapoda).

PubMed

Shyamal, Sharmishtha; Anilkumar, G; Bhaskaran, R; Doss, G P; Durica, D S

2015-01-15

Metopograpsus messor, a brachyuran crab inhabiting the estuaries of North Kerala (India), is a prolific breeder releasing approximately 14-16 broods a year. The present paper reports the sequence information on the DNA binding domain (C domain, DBD), linker (D domain) and ligand binding domain (E domain, LBD) of M. messor ecdysteroid receptor (MmEcR) gene, the first grapsid brachyuran crab EcR examined. We have also measured MmEcR transcript levels in the ovary and the hepatopancreas throughout the annual cycle, with special reference to seasons of molt and reproduction. MmEcR expression in both the tissues is found to be at its peak (P<0.05) in late premolt crabs (January/May, molt/reproduction season); the expression levels are lowest (P<0.05) during June/July, when the females would neither molt nor reproduce (season for molt/reproduction repose). Intermediate levels of expression were found during the breeding season (August/December). Interestingly, this pattern of gene expression is in concordance with the fluctuating ecdysteroid levels of the hemolymph and Y organ secretory activity. The significant levels of fluctuation in the ovarian expression of MmEcR strongly suggest the ovary as a potential target for ecdysteroid action. A season-wise comparison of the gene expression reveals that ovarian MmEcR transcript levels are higher in breeding crabs (August/December) than the non-breeding animals (June/July), implicating a possible ecdysteroid role in reproduction in M. messor. Copyright © 2014 Elsevier Inc. All rights reserved.

Host partitioning by parasites in an intertidal crustacean community.

PubMed

Koehler, Anson V; Poulin, Robert

2010-10-01

Patterns of host use by parasites throughout a guild community of intermediate hosts can depend on several biological and ecological factors, including physiology, morphology, immunology, and behavior. We looked at parasite transmission in the intertidal crustacean community of Lower Portobello Bay, Dunedin, New Zealand, with the intent of: (1) mapping the flow of parasites throughout the major crustacean species, (2) identifying hosts that play the most important transmission role for each parasite, and (3) assessing the impact of parasitism on host populations. The most prevalent parasites found in 14 species of crustaceans (635 specimens) examined were the trematodes Maritrema novaezealandensis and Microphallus sp., the acanthocephalans Profilicollis spp., the nematode Ascarophis sp., and an acuariid nematode. Decapods were compatible hosts for M. novaezealandensis, while other crustaceans demonstrated lower host suitability as shown by high levels of melanized and immature parasite stages. Carapace thickness, gill morphology, and breathing style may contribute to the differential infection success of M. novaezealandensis and Microphallus sp. in the decapod species. Parasite-induced host mortality appears likely with M. novaezealandensis in the crabs Austrohelice crassa, Halicarcinus varius, Hemigrapsus sexdentatus, and Macrophthalmus hirtipes, and also with Microphallus sp. in A. crassa. Overall, the different parasite species make different use of available crustacean intermediate hosts and possibly contribute to intertidal community structure.

Whole-Organism Transcriptomic Analysis Provides Mechanistic Insight into the Acute Toxicity of Emamectin Benzoate in Daphnia magna.

PubMed

Song, You; Rundberget, Jan Thomas; Evenseth, Linn Mari; Xie, Li; Gomes, Tânia; Høgåsen, Tore; Iguchi, Taisen; Tollefsen, Knut Erik

2016-11-01

Emamectin benzoate (EMB) is an antisea lice chemical widely used in the aquaculture that may also unintentionally affect nontarget crustaceans in the environment. Although the adverse effects of this compound are well documented in various species, the full modes of action (MoAs) are still not well characterized. The current study was therefore conducted to characterize the MoAs of EMB and link perturbations of key toxicological pathways to adverse effects in the model freshwater crustacean Daphnia magna. Effects on molting and survival were determined after 48 h exposure to EMB, whereas global transcriptional changes and the ecdysone receptor (EcR) binding potency was determined to characterize the MoA. The results showed that the molting frequency and survival of D. magna decreased in a concentration-dependent manner, and the observed changes could not be attributed to direct interactions with the EcR. Major MoAs such as activation of glutamate-gated chloride channels and gamma-aminobutyric acid signaling, disruption of neuroendocrine regulation of molting, perturbation of energy homeostasis, suppression of DNA repair and induction of programmed cell death were observed by transcriptional analysis and successfully linked to the adverse effects. This study has demonstrated that acute exposure to intermediate and high pM levels of EMB may pose hazards to nontarget crustaceans in the aquatic environment.

The First Complete Mitochondrial Genome Sequences for Stomatopod Crustaceans: Implications for Phylogeny

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

Swinstrom, Kirsten; Caldwell, Roy; Fourcade, H. Matthew

2005-09-07

We report the first complete mitochondrial genome sequences of stomatopods and compare their features to each other and to those of other crustaceans. Phylogenetic analyses of the concatenated mitochondrial protein-coding sequences were used to explore relationships within the Stomatopoda, within the malacostracan crustaceans, and among crustaceans and insects. Although these analyses support the monophyly of both Malacostraca and, within it, Stomatopoda, it also confirms the view of a paraphyletic Crustacea, with Malacostraca being more closely related to insects than to the branchiopod crustaceans.

Evidence of molting and the function of "rock-nosing" behavior in bowhead whales in the eastern Canadian Arctic.

PubMed

Fortune, Sarah M E; Koski, William R; Higdon, Jeff W; Trites, Andrew W; Baumgartner, Mark F; Ferguson, Steven H

2017-01-01

Bowhead whales (Balaena mysticetus) have a nearly circumpolar distribution, and occasionally occupy warmer shallow coastal areas during summertime that may facilitate molting. However, relatively little is known about the occurrence of molting and associated behaviors in bowhead whales. We opportunistically observed whales in Cumberland Sound, Nunavut, Canada with skin irregularities consistent with molting during August 2014, and collected a skin sample from a biopsied whale that revealed loose epidermis and sloughing. During August 2016, we flew a small unmanned aerial system (sUAS) over whales to take video and still images to: 1) determine unique individuals; 2) estimate the proportion of the body of unique individuals that exhibited sloughing skin; 3) determine the presence or absence of superficial lines representative of rock-rubbing behavior; and 4) measure body lengths to infer age-class. The still images revealed that all individuals (n = 81 whales) were sloughing skin, and that nearly 40% of them had mottled skin over more than two-thirds of their bodies. The video images captured bowhead whales rubbing on large rocks in shallow, coastal areas-likely to facilitate molting. Molting and rock rubbing appears to be pervasive during late summer for whales in the eastern Canadian Arctic.

Pancrustacean phylogeny: hexapods are terrestrial crustaceans and maxillopods are not monophyletic

PubMed Central

Regier, Jerome C.; Shultz, Jeffrey W.; Kambic, Robert E.

2005-01-01

Recent molecular analyses indicate that crustaceans and hexapods form a clade (Pancrustacea or Tetraconata), but relationships among its constituent lineages, including monophyly of crustaceans, are controversial. Our phylogenetic analysis of three protein-coding nuclear genes from 62 arthropods and lobopods (Onychophora and Tardigrada) demonstrates that Hexapoda is most closely related to the crustaceans Branchiopoda (fairy shrimp, water fleas, etc.) and Cephalocarida+Remipedia, thereby making hexapods terrestrial crustaceans and the traditionally defined Crustacea paraphyletic. Additional findings are that Malacostraca (crabs, isopods, etc.) unites with Cirripedia (barnacles, etc.) and they, in turn, with Copepoda, making the traditional crustacean class Maxillopoda paraphyletic. Ostracoda (seed shrimp)—either all or a subgroup—is associated with Branchiura (fish lice) and likely to be basal to all other pancrustaceans. A Bayesian statistical (non-clock) estimate of divergence times suggests a Precambrian origin for Pancrustacea (600 Myr ago or more), which precedes the first unambiguous arthropod fossils by over 60 Myr. PMID:15734694

[Extraction method suitable for detection of unheated crustaceans including cephalothorax by ELISA].

PubMed

Shibahara, Yusuke; Yamada, Itta; Uesaka, Yoshihiko; Uneo, Noriko; Abe, Akihisa; Ohashi, Eiji; Shiomi, Kazuo

2009-08-01

When unheated whole samples of crustaceans (shrimp, prawn and crab) were analyzed with our ELISA kit (FA test EIA-Crustacean 'Nissui') using anti-tropomyosin antibodies, a remarkable reduction in reactivity was recognized. This reduction in activity was found to be due to the digestion of tropomyosin during the extraction process by proteases contained in cephalothorax. To avoid the digestion of tropomyosin by proteases, we developed an extraction method (heating method) suitable for the detection of tropomyosin in unheated crustaceans including cephalothorax. Experiments with unheated whole samples of various species of crustaceans confirmed that the heating method greatly improved the low reactivity in the standard method; the heating method gave extraction efficiencies of as high as 93-107%. Various processed crustaceans with cephalothorax, such as dry products (unheated or weakly heated products) and pickles in soy sauce (unheated products), that showed low reactivity with the standard method were confirmed to give superior results with the heating method. These results indicated that the developed heating method is suitable for detecting unheated crustaceans with cephalothorax by means of the ELISA kit.

Sex Steroids Effects on the Molting Process of the Helminth Human Parasite Trichinella spiralis

PubMed Central

Hernández-Bello, Romel; Ramirez-Nieto, Ricardo; Muñiz-Hernández, Saé; Nava-Castro, Karen; Pavón, Lenin; Sánchez-Acosta, Ana Gabriela; Morales-Montor, Jorge

2011-01-01

We evaluated the in vitro effects of estradiol, progesterone, and testosterone on the molting process, which is the initial and crucial step in the development of the muscular larvae (ML or L1) to adult worm. Testosterone had no significative effect on the molting rate of the parasite, however, progesterone decreased the molting rate about a 50% in a concentration- and time-independent pattern, while estradiol had a slight effect (10%). The gene expression of caveolin-1, a specific gene used as a marker of parasite development, showed that progesterone and estradiol downregulated its expression, while protein expression was unaffected. By using flow citometry, a possible protein that is recognized by a commercial antiprogesterone receptor antibody was detected. These findings may have strong implications in the host-parasite coevolution, in the sex-associated susceptibility to this infection and could point out to possibilities to use antihormones to inhibit parasite development. PMID:22162638

Sensitivity of Crustaceans to Substrate-Borne Vibration.

PubMed

Roberts, Louise; Breithaupt, Thomas

2016-01-01

There is increasing interest in the responsiveness of crustaceans to vibrations, especially in the context of marine developments where techniques such as pile driving create strong vibrations that are readily transmitted through the seabed. Experiments were undertaken under controlled conditions to investigate the sensitivity of unconditioned crustaceans to substrate-borne vibration. The subjects were exposed to a range of frequencies and amplitudes using the staircase method of presentation to determine the thresholds of response. Behavior varied according to the strength of the stimuli and included bursts of movement and rapid bouts of movement.

Usage of energy reserves in crustaceans during starvation: status and future directions.

PubMed

Sánchez-Paz, Arturo; García-Carreño, Fernando; Muhlia-Almazán, Adriana; Peregrino-Uriarte, Alma B; Hernández-López, Jorge; Yepiz-Plascencia, Gloria

2006-04-01

In this paper, we review the current knowledge about the usage of carbohydrates, lipids and proteins as energy source by marine crustaceans during starvation. Crustaceans are a large and diverse group including some economically important species. The efforts to culture them for human consumption has prompted the interest to understand the preferences of energy sources to be applied for feed formulation and cost reduction. Important differences have been found among species and appear to be related not only to the biochemistry and physiology of nutrition, but also to the living environment of the crustaceans. Furthermore, crustaceans undergo morphological, physiological and behavioral changes due to their natural growing process that affect their feeding habits, an aspect that should be carefully considered. We discuss the current information on marine crustaceans about energy usage and describe areas of future research, where starvation studies render important insights.

Plasma biochemistry values in emperor geese (Chen canagica) in Alaska: comparisons among age, sex, incubation, and molt.

USGS Publications Warehouse

Franson, J. Christian; Hoffman, D.J.; Schmutz, J.A.

2009-01-01

Reduced populations of emperor geese (Chen canagica), a Bering Sea endemic, provided the need to assess plasma biochemistry values as indicators of population health. A precursory step to such an investigation was to evaluate patterns of variability in plasma biochemistry values among age, sex, and reproductive period. Plasma from 63 emperor geese was collected on their breeding grounds on the Yukon-Kuskokwim Delta in western Alaska, USA. The geese sampled included 18 incubating adult females captured, in mid June, on their nests by using bow nets, and 30 adults and 15 goslings captured in corral traps in late July and early August, when the adults were molting their wing feathers and the goslings were 5-6 weeks old. Plasma was evaluated for 15 biochemical parameters, by comparing results among age, sex, and sampling period (incubation versus wing-feather molt). Ten of the 15 biochemical parameters assayed differed among adults during incubation, the adults during molt, and the goslings at molt, whereas sex differences were noted in few parameters.

Model for the accumulation of strontium and calcium by recently molted crayfish (Cambarus longulus longerostris Ort.)

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

SCHURR, J. M.; STAMPER, M. N.

1962-10-01

After molting, crayfish absorbed Sr 85 rapidly; rates of uptake decreased exponentially as an upper limit was approached (T 1/2 = 1 to 2 days). A simple mathematical model attributes this limit to the number of sites available for deposition in the exoskeleton. Deposited ions are relatively immobile until 2 to 4 days prior to the next molt, when some are redistributed to the calcareous gastroliths prior to reuse.

Movements and habitat use of White-fronted Geese (Anser albifrons frontalis) during the remigial molt in arctic Alaska, USA

USGS Publications Warehouse

Flint, Paul L.; Meixell, Brandt W.

2017-01-01

Proposed oil and gas leasing in the National Petroleum Reserve - Alaska has raised questions about possible impacts of development on molting Greater White-fronted Geese (Anser albifrons frontalis) and their habitats. We used GPS transmitters to record fine-scale location data of molting and post-molt White-fronted Geese to assess patterns of movement and resource selection relative to vegetation class, year (2012, 2013), and body mass at capture. Molting White-fronted Geese were located an average of 63.3 ± 4.9 m (SE) from lakeshores. Estimated terrestrial home range size for flightless birds differed between years (2012 = 13.2 ± 2.6 km2; 2013 = 6.5 ± 1.8 km2), but did not vary among habitat strata or with body mass. Molting White-fronted Geese used sedge (Carex aquatilus) dominated low centered polygons and water more frequently than expected given proportional habitat availability, but avoided tussock tundra and wet sedge vegetation classes. Upon regaining flight, individuals tended to remain in the same general area, and the center of their home range only moved an average of 6.9 km. Greater White-fronted Geese that could fly tended to forage further from lakeshores ( = 245 m), and used a larger home range ( = 44.3 ± 9.5 km2) than when flightless.

Evidence of molting and the function of “rock-nosing” behavior in bowhead whales in the eastern Canadian Arctic

PubMed Central

Koski, William R.; Higdon, Jeff W.; Trites, Andrew W.; Baumgartner, Mark F.; Ferguson, Steven H.

2017-01-01

Bowhead whales (Balaena mysticetus) have a nearly circumpolar distribution, and occasionally occupy warmer shallow coastal areas during summertime that may facilitate molting. However, relatively little is known about the occurrence of molting and associated behaviors in bowhead whales. We opportunistically observed whales in Cumberland Sound, Nunavut, Canada with skin irregularities consistent with molting during August 2014, and collected a skin sample from a biopsied whale that revealed loose epidermis and sloughing. During August 2016, we flew a small unmanned aerial system (sUAS) over whales to take video and still images to: 1) determine unique individuals; 2) estimate the proportion of the body of unique individuals that exhibited sloughing skin; 3) determine the presence or absence of superficial lines representative of rock-rubbing behavior; and 4) measure body lengths to infer age-class. The still images revealed that all individuals (n = 81 whales) were sloughing skin, and that nearly 40% of them had mottled skin over more than two-thirds of their bodies. The video images captured bowhead whales rubbing on large rocks in shallow, coastal areas—likely to facilitate molting. Molting and rock rubbing appears to be pervasive during late summer for whales in the eastern Canadian Arctic. PMID:29166385

Biogenic amines and aggression: experimental approaches in crustaceans.

PubMed

Huber, R; Orzeszyna, M; Pokorny, N; Kravitz, E A

1997-01-01

This review summarizes our experimental approaches attempting to link amines and their metabolites to aggression in crustaceans. The results demonstrate (i) that agonistic behavior in crustaceans can be quantified, (ii) that the amines themselves have telling and subtle effects on the fighting behavior of animals, (iii) that pharmacological interventions are possible that might allow a biochemical dissection of the underlying mechanisms involved in processes like decision making in these animals, and (iv) that selective metabolites of amines are excreted in the urine of lobsters where they may serve behavioral roles. Many of the studies presented here are preliminary. Nonetheless, we believe the results are provocative and nicely complement previous detailed physiological, morphological and biochemical studies exploring the roles of amines in aggression in crustaceans. We expect that the continued use of this invertebrate model system will allow us to gain considerable insight into, and understanding of, the role served by biogenic amines in a complex behavioral process like aggression.

NHR-23 dependent collagen and hedgehog-related genes required for molting.

PubMed

Kouns, Nathaniel A; Nakielna, Johana; Behensky, Frantisek; Krause, Michael W; Kostrouch, Zdenek; Kostrouchova, Marta

2011-10-07

NHR-23, a conserved member of the nuclear receptor family of transcription factors, is required for normal development in Caenorhabditis elegans where it plays a critical role in growth and molting. In a search for NHR-23 dependent genes, we performed whole genome comparative expression microarrays on both control and nhr-23 inhibited synchronized larvae. Genes that decreased in response to nhr-23 RNAi included several collagen genes. Unexpectedly, several hedgehog-related genes were also down-regulated after nhr-23 RNAi. A homozygous nhr-23 deletion allele was used to confirm the RNAi knockdown phenotypes and the changes in gene expression. Our results indicate that NHR-23 is a critical co-regulator of functionally linked genes involved in growth and molting and reveal evolutionary parallels among the ecdysozoa. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of starvation and molting on the metabolic rate of the bed bug (Cimex lectularius L.).

PubMed

DeVries, Zachary C; Kells, Stephen A; Appel, Arthur G

2015-01-01

The bed bug (Cimex lectularius L.) is a common hematophagous pest in the urban environment and is capable of surviving extended periods of starvation. However, the relationship between starvation and metabolism in bed bugs is not well understood. To better understand this relationship, we measured the metabolism of all life stages for >900 h after feeding (starvation) using closed-system respirometry. Measurements were made around molting for the immature life stages, which occurs only after a blood meal. In addition, both mated and unmated adults were measured. Starvation and molting had significant effects on the metabolism of the bed bug. Mass-specific metabolic rate (V(O2); mL g(-1) h(-1)) declined in a curvilinear fashion with the period of starvation for adults and with the postmolting period for immature bed bugs (used to standardize all immature life stages). A standard curve was developed to depict the generalized pattern of metabolic decline observed in all life stages that molted. Individual metabolic comparisons among life stages that molted revealed some differences in metabolic rate between unmated males and females. In addition, the mass scaling coefficient was found to decline with starvation time (postmolting time) for all life stages that molted. In most life stages, the ratio of V(CO2) to V(O2) (respiratory exchange ratio) declined over time, indicating a change in metabolic substrate with starvation. Finally, daily percent loss in body mass declined in a pattern similar to that of V(O2). The observed patterns in metabolic decline are evaluated in relation to the life history of bed bugs. In addition, the evolutionary development of these patterns is discussed. The metabolic pattern after feeding was also found to share several similarities with that of other ectothermic species.

Guar meal diets as an alternative approach to inducing molt and improving Salmonella enteritidis resistance in late-phase laying hens.

PubMed

Gutierrez, O; Zhang, C; Caldwell, D J; Carey, J B; Cartwright, A L; Bailey, C A

2008-03-01

Induced molting of laying hens is a practice used by commercial egg producers to increase the productive lifetime of their flock. However, the conventional method of inducing molt, which involves removal of feed, water, or both as well as a reduction in photoperiod to less than a natural day has drawn criticism due to animal welfare and food safety concerns. The objective of this study was to explore the efficacy of diets containing high levels of guar meal (GM) in inducing molt and reducing susceptibility to Salmonella Enteritidis colonization in late-phase laying hens. Late-phase (68 wk old) Lohmann laying hens were either full-fed standard laying hen diets (nonmolted control), induced to molt by feed withdrawal, or full-fed standard laying hen diets containing 20% GM with or without 250 units/kg of mannanase Hemicell supplementation. On the fourth day of treatment, all hens were orally challenged with SE (1.65 x 10(7) cfu). Hens were killed and evaluated for Salmonella colonization and differences in organ weights 5 d postinoculation. Salmonella Enteritidis present in crop, liver, ovary, and cecal contents were significantly reduced by feeding GM with enzyme supplementation compared with feed withdrawal hens. No significant differences were observed in reproductive tract weights of molted groups, although a difference in liver weight was detected. Results indicate that feeding diets containing 20% GM are as effective as complete feed withdrawal with respect to inducing molt with the added benefit of improved resistance to Salmonella Enteritidis colonization and translocation.

Skin lipid structure controls water permeability in snake molts.

PubMed

Torri, Cristian; Mangoni, Alfonso; Teta, Roberta; Fattorusso, Ernesto; Alibardi, Lorenzo; Fermani, Simona; Bonacini, Irene; Gazzano, Massimo; Burghammer, Manfred; Fabbri, Daniele; Falini, Giuseppe

2014-01-01

The role of lipids in controlling water exchange is fundamentally a matter of molecular organization. In the present study we have observed that in snake molt the water permeability drastically varies among species living in different climates and habitats. The analysis of molts from four snake species: tiger snake, Notechis scutatus, gabon viper, Bitis gabonica, rattle snake, Crotalus atrox, and grass snake, Natrix natrix, revealed correlations between the molecular composition and the structural organization of the lipid-rich mesos layer with control in water exchange as a function of temperature. It was discovered, merging data from micro-diffraction and micro-spectroscopy with those from thermal, NMR and chromatographic analyses, that this control is generated from a sophisticated structural organization that changes size and phase distribution of crystalline domains of specific lipid molecules as a function of temperature. Thus, the results of this research on four snake species suggest that in snake skins different structured lipid layers have evolved and adapted to different climates. Moreover, these lipid structures can protect, "safety", the snakes from water lost even at temperatures higher than those of their usual habitat. Copyright © 2013 Elsevier Inc. All rights reserved.

Hemocyanin with phenoloxidase activity in the chitin matrix of the crayfish gastrolith.

PubMed

Glazer, Lilah; Tom, Moshe; Weil, Simy; Roth, Ziv; Khalaila, Isam; Mittelman, Binyamin; Sagi, Amir

2013-05-15

Gastroliths are transient extracellular calcium deposits formed by the crayfish Cherax quadricarinatus von Martens on both sides of the stomach wall during pre-molt. Gastroliths are made of a rigid chitinous organic matrix, constructed as sclerotized chitin-protein microfibrils within which calcium carbonate is deposited. Although gastroliths share many characteristics with the exoskeleton, they are simpler in structure and relatively homogeneous in composition, making them an excellent cuticle-like model for the study of cuticular proteins. In searching for molt-related proteins involved in gastrolith formation, two integrated approaches were employed, namely the isolation and mass spectrometric analysis of proteins from the gastrolith matrix, and 454-sequencing of mRNAs from both the gastrolith-forming and sub-cuticular epithelia. SDS-PAGE separation of gastrolith proteins revealed a set of bands at apparent molecular masses of 75-85 kDa; mass spectrometry data matched peptide sequences from the deduced amino acid sequences of seven hemocyanin transcripts. This assignment was then examined by immunoblot analysis using anti-hemocyanin antibodies, also used to determine the spatial distribution of the proteins in situ. Apart from contributing to oxygen transport, crustacean hemocyanins were previously suggested to be involved in several aspects of the molt cycle, including hardening of the new post-molt exoskeleton via phenoloxidation. The phenoloxidase activity of gastrolith hemocyanins was demonstrated. It was also noted that hemocyanin transcript expression during pre-molt was specific to the hepatopancreas. Our results thus reflect a set of functionally versatile proteins, expressed in a remote metabolic tissue and dispersed via the hemolymph to perform different roles in various organs and structures.

Size dimorphism, molt status, and body mass variation of Prairie Falcons nesting in the Snake River Birds of Prey National Conservation Area

USGS Publications Warehouse

Steenhof, Karen; McKinley, James O.

2006-01-01

Birds face challenges in how they allocate energy during the reproductive season. Most temperate zone species do not breed and molt at the same time, presumably because of the high energy demands of these two activities (Espie et al. 1996 and citations therein). However, representatives of at least four raptor genera are known to molt during the nesting season (Schmutz and Schmutz 1975, Newton and Marquiss 1982, Schmutz 1992, Espie et al. 1996). Molt strategies vary among raptor species depending on prey abundance, migration strategies, and the relative costs of reproduction. Sexually-dimorphic raptors typically have different roles in parenting, which result in different strategies for energy allocation. Male and female Eurasian Kestrels (Falco tinnunculus), for example, exhibit different molt patterns and mass changes during the breeding season (Village 1990). Prairie Falcons (Falco mexicanus) are similar to Eurasian Kestrels in that males provide most of the prey to females and young during the first part of the nesting season (Holthuijzen 1990), but no published data exist on molt patterns or mass changes in Prairie Falcons. Reliable information about raptor molt and morphometrics has important implications for modeling energetics and for understanding the role of sexes in raising young. Such knowledge also has practical application for distinguishing sexes of raptors and for determining appropriate size limits of transmitters used for telemetry studies. In this paper, we report on morphometric characteristics useful in distinguishing sexes of Prairie Falcons captured during several breeding seasons in the Snake River Birds of Prey National Conservation Area (NCA), and we assess changes in mass and molt status through the nesting season.

Habitat use and foraging patterns of molting male Long-tailed Ducks in lagoons of the central Beaufort Sea, Alaska

USGS Publications Warehouse

Flint, Paul L.; Reed, John; Deborah Lacroix,; Richard Lanctot,

2016-01-01

From mid-July through September, 10 000 to 30 000 Long-tailed Ducks (Clangula hyemalis) use the lagoon systems of the central Beaufort Sea for remigial molt. Little is known about their foraging behavior and patterns of habitat use during this flightless period. We used radio transmitters to track male Long-tailed Ducks through the molt period from 2000 to 2002 in three lagoons: one adjacent to industrial oil field development and activity and two in areas without industrial activity. We found that an index to time spent foraging generally increased through the molt period. Foraging, habitat use, and home range size showed similar patterns, but those patterns were highly variable among lagoons and across years. Even with continuous daylight during the study period, birds tended to use offshore areas during the day for feeding and roosted in protected nearshore waters at night. We suspect that variability in behaviors associated with foraging, habitat use, and home range size are likely influenced by availability of invertebrate prey. Proximity to oil field activity did not appear to affect foraging behaviors of molting Long-tailed Ducks.

Evaluation of limit feeding corn and distillers dried grains with solubles in non-feed-withdrawal molt programs for laying hens.

PubMed

Mejia, L; Meyer, E T; Utterback, P L; Utterback, C W; Parsons, C M; Koelkebeck, K W

2010-03-01

An experiment was conducted using 504 Hy-Line W-36 Single Comb White Leghorn hens (69 wk of age) randomly assigned to 1 of 7 treatments. These treatments consisted of a 47% corn:47% soy hulls diet (C:SH) fed ad libitum; a 94% corn diet fed at a rate of 36.3, 45.4, or 54.5 g/hen per day (CORN 36, CORN 45, and CORN 54, respectively); and a 94% corn distillers dried grains with solubles (DDGS) diet fed at the same rates as the previous corn diets (DDGS 36, DDGS 45, and DDGS 54, respectively) during the molt period of 28 d. The intent was to feed the DDGS diets for 28 d; however, all hens on these diets had very low feed intakes and greater than anticipated BW loss. Thus, they were switched to a 16% CP corn-soybean meal layer diet on d 19 of the molt period. At d 28, hens on all treatments were fed the same corn-soybean meal layer diet for 39 wk (73 to 112 wk of age). All DDGS diets and the CORN 36 diet resulted in total cessation of egg production during the molt period and egg production of hens fed the CORN 45, CORN 54, and C:SH diets had decreased to 3 and 4%, respectively, by d 28. Body weight loss during the 28-d molt period ranged from 14% for the CORN 54 diet to approximately 23% for the 3 DDGS diets. Postmolt egg production (5 to 43 wk) was higher for hens fed the DDGS molt diets than those fed the corn diets. There were no consistent differences in egg mass, egg-specific gravity, feed efficiency, or layer feed consumption among molt treatments for the postmolt period. These results indicate that limit feeding corn diet and DDGS diet in non-feed-withdrawal molt programs will yield long-term postmolt performance that is comparable to that observed by ad libitum feeding a C:SH diet.

Using body mass dynamics to examine long-term habitat shifts of arctic-molting geese: Evidence for ecological change

USGS Publications Warehouse

Lewis, Tyler L.; Flint, Paul L.; Derksen, Dirk V.; Schmutz, Joel A.; Taylor, Eric J.; Bollinger, Karen S.

2011-01-01

From 1976 onward, molting brant geese (Branta bernicla) within the Teshekpuk Lake Special Area, Alaska, shifted from inland, freshwater lakes toward coastal wetlands. Two hypotheses explained this redistribution: (1) ecological change: redistribution of molting brant reflects improvements in coastal foraging habitats, which have undergone a succession toward salt-tolerant plants due to increased coastal erosion and saltwater intrusion as induced by climate change or (2) interspecific competition: greater white-fronted geese (Anser albifrons) populations increased 12-fold at inland lakes, limiting food availability and forcing brant into coastal habitats. Both hypotheses presume that brant redistributions were driven by food availability; thus, body mass dynamics may provide insight into the relevance of these hypotheses. We compared body mass dynamics of molting brant across decades (1978, 1987–1992, 2005–2007) and, during 2005–2007, across habitats (coastal vs. inland). Brant lost body mass during molt in all three decades. At inland habitats, rates of mass loss progressively decreased by decade despite the increased number of greater white-fronted geese. These results do not support an interspecific competition hypothesis, instead suggesting that ecological change enhanced foraging habitats for brant. During 2005–2007, rates of mass loss did not vary by habitat. Thus, while habitats have improved from earlier decades, our results cannot distinguish between ecological changes at inland versus coastal habitats. However, we speculate that coastal forage quality has improved beyond that of inland habitats and that the body mass benefits of these higher quality foods are offset by the disproportionate number of brant now molting coastally.

Reservoirs and alternate hosts for pathogens of commercially important crustaceans: a review.

PubMed

Small, Hamish J; Pagenkopp, Katrina M

2011-01-01

There is a considerable body of literature describing the causative agents of many diseases of crustaceans. Given that many of these crustaceans support commercially important fisheries, it is somewhat surprising that comparatively little information is available regarding the natural transmission pathways and reservoirs of many of the disease-causing agents. In this paper we review what is known about reservoirs and alternate hosts for several important diseases of commercially important crustaceans and provide recommendations on future areas of research. Copyright © 2010 Elsevier Inc. All rights reserved.

Distribution and function of splash, an achaete-scute homolog in the adult olfactory organ of the Caribbean spiny lobster Panulirus argus

PubMed Central

Tadesse, Tizeta; Schmidt, Manfred; Walthall, William W.; Tai, Phang C.; Derby, Charles D.

2011-01-01

achaete-scute complex (ASC) genes, which encode basic helix-loop-helix transcription factors, regulate embryonic and adult neurogenesis in many animals. In adult arthropods, including crustaceans, ASC homologs have been identified but rarely functionally characterized. We took advantage of the recently identified crustacean homolog, splash (spiny lobster achaete scute homolog), in the olfactory organ of the Caribbean spiny lobster Panulirus argus to examine its role in adult neurogenesis. We tested the hypothesis that splash is associated with but not restricted to sensory neuron formation in the olfactory organ, the antennular lateral flagellum (LF), of adult spiny lobsters. We demonstrated splash labeling in epithelial cells across LF developmental zones (i.e., proliferation and mature zones), in auxiliary cells surrounding dendrites of olfactory receptor neurons (ORNs), and in immature and mature ORNs, but not in granulocytes or chromatophores. Since ORN proliferation varies with molt stage, we examined splash expression across molt stages and found that molt stage affected splash expression in the ORN mature zone but not in the proliferation zone. In vivo incorporation of bromodeoxyuridine (BrdU) showed no correlation in the cellular pattern of splash expression and BrdU labeling. The intensity of splash labeling was dramatically enhanced in the proliferation zones following LF damage, suggesting enhanced splash expression during repair and/or regeneration. We conclude that splash is not closely associated with the formation of sensory neurons under normal physiological conditions, and we propose that splash is involved in repair and regeneration. We also propose that splash has additional roles other than neurogenesis in adult crustaceans. PMID:21394934

Distribution and function of splash, an achaete-scute homolog in the adult olfactory organ of the Caribbean spiny lobster Panulirus argus.

PubMed

Tadesse, Tizeta; Schmidt, Manfred; Walthall, William W; Tai, Phang C; Derby, Charles D

2011-04-01

achaete-scute complex (ASC) genes, which encode basic helix-loop-helix transcription factors, regulate embryonic and adult neurogenesis in many animals. In adult arthropods, including crustaceans, ASC homologs have been identified but rarely functionally characterized. We took advantage of the recently identified crustacean homolog, splash (spiny lobster achaete scute homolog), in the olfactory organ of the Caribbean spiny lobster Panulirus argus to examine its role in adult neurogenesis. We tested the hypothesis that splash is associated with but not restricted to sensory neuron formation in the olfactory organ, the antennular lateral flagellum (LF), of adult spiny lobsters. We demonstrated splash labeling in epithelial cells across LF developmental zones (i.e., proliferation and mature zones), in auxiliary cells surrounding dendrites of olfactory receptor neurons (ORNs), and in immature and mature ORNs, but not in granulocytes or chromatophores. Since ORN proliferation varies with molt stage, we examined splash expression across molt stages and found that molt stage affected splash expression in the ORN mature zone but not in the proliferation zone. In vivo incorporation of bromodeoxyuridine (BrdU) showed no correlation in the cellular pattern of splash expression and BrdU labeling. The intensity of splash labeling was dramatically enhanced in the proliferation zones following LF damage, suggesting enhanced splash expression during repair and/or regeneration. We conclude that splash is not closely associated with the formation of sensory neurons under normal physiological conditions, and we propose that splash is involved in repair and regeneration. We also propose that splash has additional roles other than neurogenesis in adult crustaceans. 2010 Wiley Periodicals, Inc.

Male but not female olfaction is crucial for intermolt mating in European lobsters (Homarus gammarus L.).

PubMed

Skog, Malin

2009-02-01

Chemical signals are common in most crustacean social interactions and are often perceived via chemosensory (olfactory) organs on the first antenna. Intermolt courtship behaviors and mating were investigated in size-matched pairs of intermolt European lobsters (Homarus gammarus) where the olfactory receptors of either the male or the female were lesioned with distilled water (olfactory ablation) or seawater (control). Matings or advanced male courtship behaviors (mounting and turning) were common in seawater controls and olfactory-ablated females. In contrast, when male olfaction was ablated with distilled water, there was not a single mating, and the only male courtship behaviors seen were a few very brief and unsuccessful mounting attempts. Individual females mated up to 5 times with different males, showing that previously inseminated females were still attractive to males. Thus, male but not female olfaction is crucial for intermolt mating in H. gammarus, indicating the presence of a female sex pheromone during the entire female molt cycle, not only at the time of molting. Female sex discrimination may be based on other cues from the male in combination with typical male behaviors.

ROS signaling pathways and biological rhythms: perspectives in crustaceans.

PubMed

Fanjul-Moles, Maria Luisa

2013-01-01

This work reviews concepts regarding the endogenous circadian clock and the relationship between oxidative stress (OS), light and entrainment in different organisms including crustaceans, particularly crayfish. In the first section, the molecular control of circadian rhythms in invertebrates, particularly in Drosophila, is reviewed, and this model is contrasted with recent reports on the circadian genes and proteins in crayfish. Second, the redox mechanisms and signaling pathways that participate in the entrainment of the circadian clock in different organisms are reviewed. Finally, the light signals and transduction pathways involved in the entrainment of the circadian clock, specifically in relation to cryptochromes (CRYs) and their dual role in the circadian clock of different animal groups and their possible relationship to the circadian clock and redox mechanisms in crustaceans is discussed. The relationship between metabolism, ROS signals and transcription factors, such as HIF-1 alpha in crayfish, as well as the possibility that HIF-1 alpha participates in the regulation of circadian control genes (ccgs) in crustaceans is discussed.

Fine scale movements and habitat use of black brant during the flightless Wing Molt in Arctic Alaska

USGS Publications Warehouse

Lewis, Tyler L.; Flint, Paul L.; Derksen, Dirk V.; Schmutz, Joel A.

2011-01-01

Thousands of Black Brant (Branta bernicla nigricans) migrate annually to the Teshekpuk Lake Special Area (TLSA), Alaska, to undergo the flightless wing molt on tundra lakes and wetlands. GPS transmitters were attached to Brant over two summers (2007–2008) to examine patterns of movement and habitat use of molting Brant, including variation by habitat type, year and body mass. Molting Brant were located an average of 31 ± 1 m (SE) from shore and this distance did not vary across any of the explanatory variables. Brant moved an average of 123 ± 3 m hr-1 while flightless. Movement rates varied by year, averaging 22 ± 12 m hr-1 faster in 2008, and across habitat types, averaging 22 ± 13 m hr-1 faster in inland versus coastal and estuarine habitats. Two kernel home ranges were estimated: entire home range, which encompassed the complete 95% probability contour, and shoreline home range, which included only shoreline areas used by molting Brant. Entire home range (x bar = 15.1 ± 2.2 km2) was negatively correlated with body mass, suggesting that heavier individuals have more body reserves to contribute to feather growth and thereby require less food and smaller home ranges. Conversely, shoreline home range (x bar = 4.3 ± 0.6 km2) did not vary by body mass, but rather by habitat type, being larger in estuarine habitats. The complex shorelines and numerous deltaic islands of estuarine habitats offer more shoreline per area than either coastal or inland habitats. Brant appear to have limited ability to adjust their home range size or forage further from shore in response to variable food resources across years or habitats, instead altering their movement rate. Given this apparent lack of behavioral flexibility, Brant may be sensitive to development-related disturbances or habitat losses at molt sites in the TLSA.

Corticosterone stress response and plasma metabolite levels during breeding and molt in a free-living migratory songbird, the wood thrush (Hylocichla mustelina).

PubMed

Done, Tyler; Gow, Elizabeth A; Stutchbury, Bridget J M

2011-04-01

Many birds face energetic trade-offs between different life history stages, such as reproductive effort, feather molt and the non-breeding period. Little is known about how physiological measures of condition (corticosterone, plasma metabolites) in free-living birds change from nesting stages to the post-breeding molt period or whether this is influenced by prior reproductive effort. We evaluated whether corticosterone (CORT) and plasma metabolite levels vary with date, nest stage and sex in a free-living migratory songbird, the wood thrush (Hylocichla mustelina). We also tested whether (1) baseline CORT levels early in the season were predictive of subsequent reproductive success and (2) whether prior reproductive effort influenced CORT levels and blood metabolites during molt. Baseline CORT levels decreased with date during both the incubation stage and nestling stage, but did not vary significantly across stage of breeding season. Stress-induced CORT declined with date during incubation and varied significantly across breeding stage, with lower levels during feather molt. Profiles of the metabolites of β-hydroxybutyrate, glycerol, and triglyceride did not vary significantly with date or breeding stage. Only triglycerides varied significantly with sex, with females having higher levels than males. Reproductive output was highly variable (0-10 fledglings per season) but baseline CORT levels in females during the first incubation period of the season was not related to subsequent reproductive output. Prior reproductive effort, measured as the cumulative number of young hatched during the breeding season, was positively related to stress-induced CORT during molt. High reproductive effort in wood thrush appears to have physiological carry-over effects into the molt period which could potentially affect rate of molt and preparation for fall migration. Copyright © 2011. Published by Elsevier Inc.

Filling the gap between identified neuroblasts and neurons in crustaceans adds new support for Tetraconata

PubMed Central

Ungerer, Petra; Scholtz, Gerhard

2007-01-01

The complex spatio-temporal patterns of development and anatomy of nervous systems play a key role in our understanding of arthropod evolution. However, the degree of resolution of neural processes is not always detailed enough to claim homology between arthropod groups. One example is neural precursors and their progeny in crustaceans and insects. Pioneer neurons of crustaceans and insects show some similarities that indicate homology. In contrast, the differentiation of insect and crustacean neuroblasts (NBs) shows profound differences and their homology is controversial. For Drosophila and grasshoppers, the complete lineage of several NBs up to formation of pioneer neurons is known. Apart from data on median NBs no comparable results exist for Crustacea. Accordingly, it is not clear where the crustacean pioneer neurons come from and whether there are NBs lateral to the midline homologous to those of insects. To fill this gap, individual NBs in the ventral neuroectoderm of the crustacean Orchestia cavimana were labelled in vivo with a fluorescent dye. A partial neuroblast map was established and for the first time lineages from individual NBs to identified pioneer neurons were established in a crustacean. Our data strongly suggest homology of NBs and their lineages, providing further evidence for a close insect–crustacean relationship. PMID:18048285

Dietary mercury exposure causes decreased escape takeoff flight performance and increased molt rate in European starlings (Sturnus vulgaris).

PubMed

Carlson, Jenna R; Cristol, Daniel; Swaddle, John P

2014-10-01

Mercury is a widespread and persistent environmental contaminant that occurs in aquatic and terrestrial habitats. Recently, songbirds that forage from primarily terrestrial sources have shown evidence of bioaccumulation of mercury, but little research has assessed the effects of mercury on their health and fitness. There are many indications that mercury negatively affects neurological functioning, bioenergetics, and behavior through a variety of mechanisms and in a wide array of avian taxa. Effective flight is crucial to avian fitness and feather molt is an energetically expensive life history trait. Therefore, we investigated whether mercury exposure influenced flight performance and molt in a common songbird, the European starling (Sturnus vulgaris). Specifically, we dosed the diet of captive starlings with methylmercury cysteine at 0.0, 0.75, or 1.5 μg/g wet weight and recorded changes in flight performance after 1 year of dietary mercury exposure. We also recorded the annual molt of wing feathers. We found that individuals dosed with mercury exhibited decreased escape takeoff flight performance compared with controls and blood mercury was also correlated with an increased rate of molt, which can reduce flight performance and thermoregulatory ability. This study reveals two novel endpoints, flight performance and molt, that may be affected by dietary mercury exposure. These findings suggest a potential impact on wild songbirds exposed to mercury levels comparable to the high dosage levels in the present study. Any decrease in flight efficiency could reduce fitness due to a direct impact on survival during predation events or by decreased efficiency in other critical activities (such as foraging or migration) that require efficient flight.

Calcium transport mechanism in molting crayfish revealed by microanalysis

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

Mizuhira, V.; Ueno, M.

1983-01-01

Crayfish provide a good model in which to study the transport mechanism of Ca ions. During the molting stage, decalcified Ca ions are transferred into the blood and accumulate in the gastrolith epithelium, after which a gastrolith is formed on the surface of the epithelium. The gastrolith is dissolved in the stomach after molting, and the Ca is reabsorbed and redistributed throughout the newly formed exoskeleton. We studied the mechanism of Ca transport by cytochemical precipitation of Ca ions and by electron microanalysis, including X-ray microanalysis (EDX) and electron energy-loss spectroscopy (EELS), with a computer. In EDX analysis, the finemore » precipitates of K-antimonate in the gastrolith mitochondria clearly defined Ca with antimony; we also observed a large amount of Ca-oxalate in the mitochondria, and Ca-K X-ray pulses were clearly defined. Ca-K X-rays were also detected from fresh freeze-substituted mitochondria. Finally, we succeeded in taking a Ca-L EELS image from the mitochondria of fresh freeze-substituted thin sections. Only a very small amount of Ca was detected from the cell membrane and other organelles. Ca-adenosine triphosphatase (ATPase) and Mg-ATPase activity was also very clearly demonstrated in the mitochondria. These enzymes may play an important role in Ca metabolism.« less

Neural processing, perception, and behavioral responses to natural chemical stimuli by fish and crustaceans.

PubMed

Derby, Charles D; Sorensen, Peter W

2008-07-01

This manuscript reviews the chemical ecology of two of the major aquatic animal models, fish and crustaceans, in the study of chemoreception. By necessity, it is restricted in scope, with most emphasis placed on teleost fish and decapod crustaceans. First, we describe the nature of the chemical world perceived by fish and crustaceans, giving examples of the abilities of these animals to analyze complex natural odors. Fish and crustaceans share the same environments and have evolved some similar chemosensory features: the ability to detect and discern mixtures of small metabolites in highly variable backgrounds and to use this information to identify food, mates, predators, and habitat. Next, we give examples of the molecular nature of some of these natural products, including a description of methodologies used to identify them. Both fish and crustaceans use their olfactory and gustatory systems to detect amino acids, amines, and nucleotides, among many other compounds, while fish olfactory systems also detect mixtures of sex steroids and prostaglandins with high specificity and sensitivity. Third, we discuss the importance of plasticity in chemical sensing by fish and crustaceans. Finally, we conclude with a description of how natural chemical stimuli are processed by chemosensory systems. In both fishes and crustaceans, the olfactory system is especially adept at mixture discrimination, while gustation is well suited to facilitate precise localization and ingestion of food. The behaviors of both fish and crustaceans can be defined by the chemical worlds in which they live and the abilities of their nervous systems to detect and identify specific features in their domains. An understanding of these worlds and the sensory systems that provide the animals with information about them provides insight into the chemical ecology of these species.

Undesirable Enzymatic Browning in Crustaceans: Causative Effects and Its Inhibition by Phenolic Compounds.

PubMed

Nirmal, Nilesh Prakash; Benjakul, Soottawat; Ahmad, Mehraj; Arfat, Yasir Ali; Panichayupakaranant, Pharkphoom

2015-01-01

Undesirable enzymatic browning mediated by polyphenol oxidase (E.C. 1.14.18.1) on the surface of seafood from crustaceans have been a great concern to food processors, causing quality losses of seafood products. Seafoods especially from crustaceans are worldwide consumed due to their delicacy and nutritional value. However, black spot formation (melanosis) is the major problem occurring in crustaceans during postmortem handling and refrigerated storage induce deleterious changes in organoleptic properties and, therefore, decreases commercial value. Polyphenoloxidase (PPO), the copper-containing metalloprotein involved in oxidation of phenol to quinone is the major biochemical reaction of melanosis formation. This enzymatic mechanism causes unappealing blackening in postharvest crustaceans. To alleviate the melanosis formation in crustaceans, use of phenolic compounds from plant extract can serve as antimelanotics and appears to be a good alternative to the conventional sulfites which are associated with health-related disorders. In this review, we focuses on the unique features about the structure, distribution, and properties of PPO as well as mechanism of melanosis formation and provide a comprehensive deeper insight on the factors affecting melanosis formation and its inhibition by various antimelanotics including newly discovered plant phenolic compounds.

Chronobiology of deep-water decapod crustaceans on continental margins.

PubMed

Aguzzi, Jacopo; Company, Joan B

2010-01-01

Species have evolved biological rhythms in behaviour and physiology with a 24-h periodicity in order to increase their fitness, anticipating the onset of unfavourable habitat conditions. In marine organisms inhabiting deep-water continental margins (i.e. the submerged outer edges of continents), day-night activity rhythms are often referred to in three ways: vertical water column migrations (i.e. pelagic), horizontal displacements within benthic boundary layer of the continental margin, along bathymetric gradients (i.e. nektobenthic), and endobenthic movements (i.e. rhythmic emergence from the substrate). Many studies have been conducted on crustacean decapods that migrate vertically in the water column, but much less information is available for other endobenthic and nektobenthic species. Also, the types of displacement and major life habits of most marine species are still largely unknown, especially in deep-water continental margins, where steep clines in habitat factors (i.e. light intensity and its spectral quality, sediment characteristics, and hydrography) take place. This is the result of technical difficulties in performing temporally scheduled sampling and laboratory testing on living specimens. According to this scenario, there are several major issues that still need extensive research in deep-water crustacean decapods. First, the regulation of their behaviour and physiology by a biological clock is almost unknown compared to data for coastal species that are easily accessible to direct observation and sampling. Second, biological rhythms may change at different life stages (i.e. size-related variations) or at different moments of the reproductive cycle (e.g. at egg-bearing) based on different intra- and interspecific interactions. Third, there is still a major lack of knowledge on the links that exist among the observed bathymetric distributions of species and selected autoecological traits that are controlled by their biological clock, such as the

Sensitization pattern of crustacean-allergic individuals can indicate allergy to molluscs.

PubMed

Vidal, C; Bartolomé, B; Rodríguez, V; Armisén, M; Linneberg, A; González-Quintela, A

2015-11-01

This study investigated the sensitization pattern of crustacean-allergic patients according to tolerance to molluscs. Thirty-one patients with anaphylaxis to crustaceans (14 with mollusc allergy and 17 with mollusc tolerance) were studied using skin prick tests (SPTs), specific IgEs (sIgEs) and SDS-PAGE immunoblotting. IgE-reactive shrimp proteins were identified by proteomic analyses. Patients with mollusc allergy presented more frequently SPTs positive to molluscs and higher sIgE titres in response to both molluscs and crustaceans. Shrimp-sIgE and rPen a1-sIgE values of 1.57 kUA /l and 4.38 kUA /l, respectively, showed positive likelihood ratios of 4.3 and 10.9 for the identification of mollusc allergy. Patients with mollusc allergy reacted more frequently to tropomyosin in immunoblots than did patients without it (93% vs 35%, respectively, P = 0.004). Reactivity to proteins other than tropomyosin (n = 14) was not different between the two groups. Among patients with crustacean anaphylaxis, patients with mollusc allergy and mollusc tolerance show a different pattern of sensitization, something that may help identify them. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Characterization of a molt-inhibiting hormone (MIH) of the crayfish, Orconectes limosus, by cDNA cloning and mass spectrometric analysis.

PubMed

Bulau, Patrick; Okuno, Atsuro; Thome, Elke; Schmitz, Tina; Peter-Katalinic, Jasna; Keller, Rainer

2005-11-01

The structure of the precursor of a molt-inhibiting hormone (MIH) of the American crayfish, Orconectes limosus was determined by cloning of a cDNA based on RNA from the neurosecretory perikarya of the X-organ in the eyestalk ganglia. The open reading frame includes the complete precursor sequence, consisting of a signal peptide of 29, and the MIH sequence of 77 amino acids. In addition, the mature peptide was isolated by HPLC from the neurohemal sinus gland and analyzed by ESI-MS and MALDI-TOF-MS peptide mapping. This showed that the mature peptide (Mass 8664.29 Da) consists of only 75 amino acids, having Ala75-NH2 as C-terminus. Thus, C-terminal Arg77 of the precursor is removed during processing, and Gly76 serves as an amide donor. Sequence comparison confirms this peptide as a novel member of the large family, which includes crustacean hyperglycaemic hormone (CHH), MIH and gonad (vitellogenesis)-inhibiting hormone (GIH/VIH). The lack of a CPRP (CHH-precursor related peptide) in the hormone precursor, the size and specific sequence characteristics show that Orl MIH belongs to the MIH/GIH(VIH) subgroup of this larger family. Comparison with the MIH of Procambarus clarkii, the only other MIH that has thus far been identified in freshwater crayfish, shows extremely high sequence conservation. Both MIHs differ in only one amino acid residue ( approximately 99% identity), whereas the sequence identity to several other known MIHs is between 40 and 46%.

Crustacean zooplankton release copious amounts of dissolved organic matter as taurine in the ocean.

PubMed

Clifford, Elisabeth L; Hansell, Dennis A; Varela, Marta M; Nieto-Cid, Mar; Herndl, Gerhard J; Sintes, Eva

2017-11-01

Taurine (Tau), an amino acid-like compound, is present in almost all marine metazoans including crustacean zooplankton. It plays an important physiological role in these organisms and is released into the ambient water throughout their life cycle. However, limited information is available on the release rates by marine organisms, the concentrations and turnover of Tau in the ocean. We determined dissolved free Tau concentrations throughout the water column and its release by abundant crustacean mesozooplankton at two open ocean sites (Gulf of Alaska and North Atlantic). At both locations, the concentrations of dissolved free Tau were in the low nM range (up to 15.7 nM) in epipelagic waters, declining sharply in the mesopelagic to about 0.2 nM and remaining fairly stable throughout the bathypelagic waters. Pacific amphipod-copepod assemblages exhibited lower dissolved free Tau release rates per unit biomass (0.8 ± 0.4 μmol g -1 C-biomass h -1 ) than Atlantic copepods (ranging between 1.3 ± 0.4 μmol g -1 C-biomass h -1 and 9.5 ± 2.1 μmol g -1 C-biomass h -1 ), in agreement with the well-documented inverse relationship between biomass-normalized excretion rates and body size. Our results indicate that crustacean zooplankton might contribute significantly to the dissolved organic matter flux in marine ecosystems via dissolved free Tau release. Based on the release rates and assuming steady state dissolved free Tau concentrations, turnover times of dissolved free Tau range from 0.05 d to 2.3 d in the upper water column and are therefore similar to those of dissolved free amino acids. This rapid turnover indicates that dissolved free Tau is efficiently consumed in oceanic waters, most likely by heterotrophic bacteria.

Exceptionally preserved crustaceans from western Canada reveal a cryptic Cambrian radiation

NASA Astrophysics Data System (ADS)

Harvey, Thomas H. P.; Vélez, Maria I.; Butterfield, Nicholas J.

2012-01-01

The early history of crustaceans is obscured by strong biases in fossil preservation, but a previously overlooked taphonomic mode yields important complementary insights. Here we describe diverse crustacean appendages of Middle and Late Cambrian age from shallow-marine mudstones of the Deadwood Formation in western Canada. The fossils occur as flattened and fragmentary carbonaceous cuticles but provide a suite of phylogenetic and ecological data by virtue of their detailed preservation. In addition to an unprecedented range of complex, largely articulated filtering limbs, we identify at least four distinct types of mandible. Together, these fossils provide the earliest evidence for crown-group branchiopods and total-group copepods and ostracods, extending the respective ranges of these clades back from the Devonian, Pennsylvanian, and Ordovician. Detailed similarities with living forms demonstrate the early origins and subsequent conservation of various complex food-handling adaptations, including a directional mandibular asymmetry that has persisted through half a billion years of evolution. At the same time, the Deadwood fossils indicate profound secular changes in crustacean ecology in terms of body size and environmental distribution. The earliest radiation of crustaceans is largely cryptic in the fossil record, but "small carbonaceous fossils" reveal organisms of surprisingly modern aspect operating in an unfamiliar biosphere.

Effect of limb regeneration on size increase at molt of the shore crabs Hemigrapsus oregonensis and Pachygrapsus crassipes.

PubMed

Kuris, A M; Mager, M

1975-09-01

Size increase at molt is reduced following multiple limb regeneration in the shore crabs, Hemigrapsus oregonensis and Pachygrapsus crassipes. Limb loss per se does not influence postmolt size. Effect of increasing number of regenerating limbs is additive. Postmolt size is programmed early in the premolt period of the preceding instar and is probably not readily influenced by water uptake mechanics at ecdysis. A simple model for growth, molting, and regeneration in heavily calcified Crustacea is developed from the viewpoint of adaptive strategies and energetic considerations.

Hydrodynamics of metachronal paddling in crustaceans

NASA Astrophysics Data System (ADS)

Santhanakrishnan, A.; Lai, H. K.; Samaee, M.; Lewis, T. J.; Guy, R. D.

2016-02-01

Long-tailed crustaceans such as crayfish and krill swim by rhythmically paddling a set of four to five limbs (swimmerets) originating from their abdomen. Despite variations in limb size and stroke frequency, movements of ipsilateral limbs always maintain a tail-to-head metachronal rhythm with an approximate quarter-period inter-limb phase difference. Relatively few studies have examined the fluid dynamics of metachronal limb stroke for the range of Reynolds numbers at which crustaceans operate. The objective of this study is to investigate metachronal paddling as a function of Reynolds number (Re) for quantifying hydrodynamic scalability of this swimming mechanism, including the effect of hinges on paddles as seen in crustacean swimmerets. Our approach included experiments on a scaled physical model and computational fluid dynamics (CFD) simulations using the immersed boundary (IB) method. The scaled robotic model of metachronal paddling consisted of a rectangular aquarium tank fitted above with four stepper motors coupled to a four-bar linkage that actuated four acrylic paddles immersed in water-glycerin fluid medium. 2D particle image velocimetry (PIV) was used for quantitative flow visualization in the experiments. The swimmerets were modeled in CFD simulations as rigid 1D rods in a 2D fluid. The inter-limb phase difference was varied from 0% (synchronous paddling) through 50% across Re range of O(10-1000). Two types of experimental limb models were tested, including a simple flat plate and a `split-paddle' structure with two flat plates connected halfway with hinges. Our results show that the natural tail-to-head metachronal rhythm with an approximate quarter-period phase difference is the most effective and efficient rhythm across a wide range of Reynolds numbers. Limb models with hinges generated increased horizontal flow compared to the simple flat plate paddles, suggesting that asymmetry between power and return stroke is important to augment thrust.

EFFECT OF DIFLUBENZURON ON AN ESTUARINE CRUSTACEAN

EPA Science Inventory

Data are reported for tests exposing a small, estuarine crustacean, Mysidopsis bahia, to diflubenzuron (Dimilin, TH-6040, (1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea)) in flowing seawater. Tests were conducted in intermittent flows from a diluter or continuous flowing water i...

The mercury levels in crustaceans and cephalopods from Peninsular Malaysia.

PubMed

Ahmad, Nurul Izzah; Noh, Mohd Fairulnizal Mohd; Mahiyuddin, Wan Rozita Wan; Jaafar, Hamdan; Ishak, Ismail; Azmi, Wan Nurul Farah Wan; Veloo, Yuvaneswary; Mokhtar, Fazlin Anis

2015-09-01

This study is to determine total mercury in edible tissues of eight species of cephalopods and 12 species of crustaceans purchased from 11 identified major fish landing ports and wet markets throughout Peninsular Malaysia. The concentration of mercury was measured by cold vapor atomic absorption spectrometry (AAS) technique using the Perkin Elmer Flow Injection Mercury System (FIMS-400). In general, the mercury levels were low with concentrations in cephalopods ranging from 0.099 to 2.715 mg/kg dry weight (or 0.0184-0.505 mg/kg wet weight) and in crustaceans ranging from 0.057 to 1.359 mg/kg dry weight (or 0.0111-0.265 mg/kg wet weight). The mercury levels showed no significant differences (P > 0.05) between species for both cephalopods and crustaceans. There was no significant correlation between mercury concentrations and the body size of individual for both groups as well. Comparisons with mercury levels obtained found from other previous studies and/or species noted that they were of the same magnitude or relatively low compared to various locations reported worldwide.

Toward crustacean without chemicals: a descriptive analysis of consumer response using price comparisons

PubMed Central

Okpala, Charles Odilichukwu R.; Bono, Gioacchino; Pipitone, Vito; Vitale, Sergio; Cannizzaro, Leonardo

2016-01-01

Background To date, there seems to be limited-to-zero emphasis about how consumers perceive crustacean products subject to either chemical and or non-chemical preservative treatments. In addition, studies that investigated price comparisons of crustacean products subject to either chemical or chemical-free preservative methods seem unreported. Objective This study focused on providing some foundational knowledge about how consumers perceive traditionally harvested crustaceans that are either chemical-treated and or free of chemicals, incorporating price comparisons using a descriptive approach. Design The study design employed a questionnaire approach via interview using a computer-assisted telephone system and sampled 1,540 participants across five key locations in Italy. To actualize consumer sensitivity, ‘price’ was the focus given its crucial role as a consumption barrier. Prior to this, variables such as demographic characteristics of participants, frequency of purchasing, quality attributes/factors that limit the consumption of crustaceans were equally considered. Results By price comparisons, consumers are likely to favor chemical-free (modified atmosphere packaging) crustacean products amid a price increase of up to 15%. But, a further price increase such as by 25% could markedly damage consumers’ feelings, which might lead to a considerable number opting out in favor of either chemical-treated or other seafood products. Comparing locations, the studied variables showed no statistical differences (p>0.05). On the contrary, the response weightings fluctuated across the studied categories. Both response weightings and coefficient of variation helped reveal more about how responses deviated per variable categories. Conclusions This study has revealed some foundational knowledge about how consumers perceive traditionally harvested crustaceans that were either chemical-treated or subject to chemical-free preservative up to price sensitivity using Italy as

Selected endocrine disrupting compounds (vinclozolin, flutamide, ketoconazole and dicofol): effects on survival, occurrence of males, growth, molting and reproduction of Daphnia magna.

PubMed

Haeba, Maher H; Hilscherová, Klára; Mazurová, Edita; Bláha, Ludek

2008-05-01

Pollution-induced endocrine disruption in vertebrates and invertebrates is a worldwide environmental problem, but relatively little is known about effects of endocrine disrupting compounds (EDCs) in planktonic crustaceans (including Daphnia magna). Aims of the present study were to investigate acute 48 h toxicity and sub-chronic (4-6 days) and chronic (21 days) effects of selected EDCs in D. magna. We have investigated both traditional endpoints as well as other parameters such as sex determination, maturation, molting or embryogenesis in order to evaluate the sensitivity and possible use of these endpoints in ecological risk assessment. We have studied effects of four model EDCs (vinclozolin, flutamide, ketoconazole and dicofol) on D. magna using (i) an acute 48 h immobilization assay, (ii) a sub-chronic, 4-6 day assay evaluating development and the sex ratio of neonates, and (iii) a chronic, 21 day assay studying number of neonates, sex of neonates, molting frequency, day of maturation and the growth of maternal organisms. Acute EC50 values in the 48 h immobilization test were as follows (mg/L): dicofol 0.2, ketoconazole 1.5, flutamide 2.7, vinclozolin >3. Short-term, 4-6 day assays with sublethal concentrations showed that the sex ratio in Daphnia was modulated by vinclozolin (decreased number of neonate males at 1 mg/L) and dicofol (increase in males at 0.1 mg/L). Flutamide (up to 1 mg/L) had no effect on the sex of neonates, but inhibited embryonic development at certain stages during chronic assay, resulting in abortions. Ketoconazole had no significant effects on the studied processes up to 1 mg/L. Sex ratio modulations by some chemicals (vinclozolin and dicofol) corresponded to the known action of these compounds in vertebrates (i.e. anti-androgenicity and anti-oestrogenicity, respectively). Our study revealed that some chemicals known to affect steroid-regulated processes in vertebrates can also affect sublethal endpoints (e.g. embryonic sex determination

[Diversity and faunal analysis of crustaceans in Potatso National Park, Shangri-La, China].

PubMed

Shu, Shu-Sen; Chen, Fei-Zhou; Yang, Jun-Xing; Yang, Xiao-Jun; Chen, Xiao-Yong

2013-06-01

Potatso National Park was the first national park in mainland China, preceded by the earlier Bitahai Nature Reserve. Located in the northwest of Yunnan and on the southeast of Qinghai-Tibet plateau, Potatso is a typical low latitude and high elevation wetland nature reserve, with large areas of coniferous forest around alpine lakes and both wetland and water area ecosystems. In August, 2011, we undertook a survey of crustaceans in the park, sampling lakes, ponds, streams, and rivers throughout Potatso. We found a total of 29 species (including varieties) belonging to 24 genera and 11 families. Notable discoveries include Parartemiopsis sp, Arctodiaptomus parvispinus and Simocephalus congener, which are the first examples of these species to be recorded in China. Likewise, Gammarus bitaensis is a unique crustacean found only in Potatso National Park and Thermocyclops dumonti and Gammarus paucispinus are both endemic species to northwestern Yunnan. The overall faunal characteristics of crustaceans in the park also revealed several things about Potatso: (1) Cosmopolitan and Palaearctic elements reach 48.27% and 37.93%, clearly showing the Palaearctic element as the dominant fauna; (2) most of the crustacean, such as Arctodiaptomus parvispinus and Gammarus, are typical alpine types, confirming that Potatso has feature typical of alpine and plateau fauna; and (3) the proportion of endemic and rare crustacean species in Potatso National Park is approximately 10%, suggesting that the Potatso National Park in particular and the northwest of Yunnan in general have a unique geological and evolutionary history.

[Effects of large bio-manipulation fish pen on community structure of crustacean zooplankton in Meiliang Bay of Taihu Lake].

PubMed

Ke, Zhi-Xin; Xie, Ping; Guo, Long-Gen; Xu, Jun; Zhou, Qiong

2012-08-01

In 2005, a large bio-manipulation pen with the stock of silver carp and bighead carp was built to control the cyanobacterial bloom in Meiliang Bay of Taihu Lake. This paper investigated the seasonal variation of the community structure of crustacean zooplankton and the water quality within and outside the pen. There were no significant differences in the environmental parameters and phytoplankton biomass within and outside the pen. The species composition and seasonal dynamics of crustacean zooplankton within and outside the pen were similar, but the biomass of crustacean zooplankton was greatly suppressed by silver carp and bighead carp. The total crustacean zooplankton biomass and cladocerans biomass were significantly lower in the pen (P < 0.05). In general, silver carp and bighead carp exerted more pressure on cladoceran species than on copepod species. A distinct seasonal succession of crustacean zooplankton was observed in the Bay. Many crustacean species were only dominated in given seasons. Large-sized crustacean (mainly Daphnia sp. and Cyclops vicnus) dominated in winter and spring, while small-sized species (mainly Bosmina sp., Ceriodaphnia cornuta, and Limnoithona sinensis) dominated in summer and autumn. Canonical correspondence analysis showed that water transparency, temperature, and phytoplankton biomass were the most important factors affecting the seasonal succession of the crustacean.

Local knowledge of traditional fishermen on economically important crabs (Decapoda: Brachyura) in the city of Conde, Bahia State, Northeastern Brazil.

PubMed

de Magalhães, Henrique Fernandes; Costa Neto, Eraldo Medeiros; Schiavetti, Alexandre

2012-07-02

This article records the traditional knowledge of crab gatherers in the city of Conde, in the North Coast Region of Bahia State, Northeastern Brazil. Data on biological and ecological aspects of economically important brachyuran crustaceans have been obtained from semi-structured interviews and in loco observations conducted from September 2007 to December 2009. A total of 57 fishermen of both genders, aged between 10 and 78 years have been interviewed (individually or collectively) in different contexts; interviewees were asked about aspects such as external morphology, life cycle, trophic ecology, and spatial and temporal distribution of the major economically important brachyuran crustaceans in the region. Seven fishing communities were visited: Siribinha, Sítio do Conde, Poças, Ilha das Ostras, Cobó, Buri and Sempre Viva. Data were analyzed by comparing the information provided by participants with those from the specialized academic literature. The results show that artisanal fishermen have a wide ranging and well-grounded knowledge on the ecological and biological aspects of crustaceans. Crab gatherers of Conde know about growth and reproductive behavior of the animals they interact with, especially with regard to the three major biological aspects: "molt", "walking dance" and "spawning". This knowledge constitutes an important source of information that should be considered in studies of management and sustainable use of fishery resources in the North Coast Region of Bahia State.

The Y-organ secretory activity fluctuates in relation to seasons of molt and reproduction in the brachyuran crab, Metopograpsus messor (Grapsidae): Ultrastructural and immunohistochemical study.

PubMed

Shyamal, Sharmishtha; Sudha, K; Gayathri, N; Anilkumar, G

2014-01-15

This paper presents a first-time report on the localization, structure and seasonal secretory activity of the Y-organ of a grapsid brachyuran crab (Metopograpsus messor). Having exhibited discrete seasonality with reference to the programming of molt and reproduction, this brachyuran crab has offered us an excellent model to obtain a clear picture of the fluctuating secretory nature of the Yorgan, all the way through the reproductive (August-December) as well as the molt-reproduction active (January-May) and inactive (June-July) seasons. Ultrastructural studies revealed that the secretion of the Y-organ was at its peak in premolt crabs during molt-reproduction season (January-May). Interestingly, the Y-organs of the intermolt females that engaged in breeding activity showed higher levels of secretion than those of the molt-reproduction inactive season (June-July), implicating the gland's involvement in reproduction. Immunohistochemical studies using the antiserum raised against 2-succinyl conjugate of ecdysone have demonstrated the ecdysteroid nature of the secretion from the Y-organ, and results of the quantitative assay of ecdysteroids (through radioimmunoassay) revealed that the hormone titer fluctuates in consonance with the Y-organ's secretory activity during seasons of molt and reproduction. Pertinently, not only that the paper gives us a comprehensive understanding on the secretory activity of the Y-organ in a season-dependent fashion, it also allows us to have a better insight into the gland's function related to molting and reproduction (for the first time) in a grapsid brachyuran crab. Copyright © 2013 Elsevier Inc. All rights reserved.

Apoptosis of leukemia K562 and Molt-4 cells induced by emamectin benzoate involving mitochondrial membrane potential loss and intracellular Ca2+ modulation.

PubMed

Yun, Xinming; Rao, Wenbing; Xiao, Ciying; Huang, Qingchun

2017-06-01

Leukemia threatens millions of people's health and lives, and the pesticide-induced leukemia has been increasingly concerned because of the etiologic exposure. In this paper, cytotoxic effect of emamectin benzoate (EMB), an excellent natural-product insecticide, was evaluated through monitoring cell viability, cell apoptosis, mitochondrial membrane potential and intracellular Ca 2+ concentration ([Ca 2+ ] i ) in leukemia K562 and Molt-4 cells. Following the exposure to EMB, cell viability was decreased and positive apoptosis of K562 and Molt-4 cells was increased in a concentration- and time- dependent fashion. In the treatment of 10μM EMB, apoptotic cells accounted for 93.0% to K562 cells and 98.9% to Molt-4 cells based on the control, meanwhile, 63.47% of K562 cells and 81.15% of Molt-4 cells exhibited late apoptotic and necrotic features with damaged cytoplasmic membrane. 48h exposure to 10μM EMB increased significantly the great number of cells with mitochondrial membrane potential (MMP) loss, and the elevation of [Ca 2+ ] i level was peaked and persisted within 70s in K562 cells whilst 50s in Molt-4 cells. Moreover, a stronger cytotoxicity of EMB was further observed than that of imatinib. The results authenticate the efficacious effect of EMB as a potential anti-leukemia agent and an inconsistency with regard to insecticide-induced leukemia. Copyright © 2017 Elsevier B.V. All rights reserved.

Survival and movements of molting male black ducks in Labrador

USGS Publications Warehouse

Bowman, Timothy D.; Longcore, J.R.

1989-01-01

We marked 26 flightless male American black ducks with transmitters during the post-nuptial molt in northern Labrabor to determine survival and movements. Twelve ducks remained in the watershed where marked and 11 ducks moved to different watersheds. The period survival rate (PSR) for these flightless males was 0.89 using the Kaplan-Meier estimator. Only 2 ducks were killed by predators. Death of these 2 ducks might have been influenced by our disturbance, thus we considered the PSR minimal.

Mitochondrial genomes suggest that hexapods and crustaceans are mutually paraphyletic

PubMed Central

Cook, Charles E; Yue, Qiaoyun; Akam, Michael

2005-01-01

For over a century the relationships between the four major groups of the phylum Arthropoda (Chelicerata, Crustacea, Hexapoda and Myriapoda) have been debated. Recent molecular evidence has confirmed a close relationship between the Crustacea and the Hexapoda, and has included the suggestion of a paraphyletic Hexapoda. To test this hypothesis we have sequenced the complete or near-complete mitochondrial genomes of three crustaceans (Parhyale hawaiensis, Squilla mantis and Triops longicaudatus), two collembolans (Onychiurus orientalis and Podura aquatica) and the insect Thermobia domestica. We observed rearrangement of transfer RNA genes only in O. orientalis, P. aquatica and P. hawaiensis. Of these, only the rearrangement in O. orientalis, an apparent autapomorphy for the collembolan family Onychiuridae, was phylogenetically informative. We aligned the nuclear and amino acid sequences from the mitochondrial protein-encoding genes of these taxa with their homologues from other arthropod taxa for phylogenetic analysis. Our dataset contains many more Crustacea than previous molecular phylogenetic analyses of the arthropods. Neighbour-joining, maximum-likelihood and Bayesian posterior probabilities all suggest that crustaceans and hexapods are mutually paraphyletic. A crustacean clade of Malacostraca and Branchiopoda emerges as sister to the Insecta sensu stricto and the Collembola group with the maxillopod crustaceans. Some, but not all, analyses strongly support this mutual paraphyly but statistical tests do not reject the null hypotheses of a monophyletic Hexapoda or a monophyletic Crustacea. The dual monophyly of the Hexapoda and Crustacea has rarely been questioned in recent years but the idea of both groups' paraphyly dates back to the nineteenth century. We suggest that the mutual paraphyly of both groups should seriously be considered. PMID:16024395

Toxicity of sodium chromate and 3,4-dichloroaniline to crustaceans

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

van der Meer, C.; Teunissen, C.; Boog, T.F.M.

1988-02-01

Small adult and larval crustaceans are important components of a number of food webs. Therefore, it is important on the one hand to determine the sensitivity of these crustaceans to environmental contaminants and on the other hand to select the most sensitive species as test organisms to help establish the permissible contamination. In brackish water adults as well as larvae of the species Palaemonetes pugio and Uca pugilator have been most frequently investigated. These species can also be studied in sea water. The marine species Carcinus maenas, Crangon septemspinosa and Homarus americanus have also been studied relatively intensively. The presentmore » paper describes the toxicity, at different salinities, of Na/sub 2/, CrO/sub 4/, (chromate) and 3,4-dichloroaniline (3,4-DCA) to a number of relatively small adult and larval crustaceans. Chromate was chosen as a model of a heavy metal since, although its toxicity may be relatively low, it may under certain circumstance have considerable environmental effects. Moreover, bichromate has been recommended as a standard in Daphnia tests. 3,4-dichloroaniline was chosen as a model of a chlorinated hydrocarbon, the handling of which does not need special precautions.« less

Links between Osmoregulation and Nitrogen-Excretion in Insects and Crustaceans.

PubMed

Weihrauch, Dirk; O'Donnell, Michael J

2015-11-01

The epithelia involved in ionoregulation and detoxification in crustaceans and insects are quite distinct: the gills, hepatopancreas, and antennal gland serve these functions in crustaceans, whereas the Malpighian tubules, hindgut, and, to some extent, the midgut, are involved in insects. This article compares the means by which the Na(+)/K(+)-ATPase and the vacuolar type H(+)-ATPase are used to energize ionoregulatory processes in both groups. The vacuolar H(+)-ATPase is particularly important as a generator of both H(+) gradients and transmembrane electrical gradients that can be used to energize electroneutral or electrogenic exchange of Na(+) and/or K(+) for H(+). In addition to cation:proton antiporters, epithelia in both groups depend upon the activity of Na(+):K(+):2Cl(-) cotransporters, Cl(-)/[Formula: see text] exchangers, and channels for K(+) and Cl(-) for transepithelial ion transport. This article also contrasts the dominant role of ammonia as the primary nitrogenous waste in crustaceans, with the excretion of ammonia, uric acid, or both in insects. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Implications of prebasic and a previously undescribed prealternate molt for aging Rusty Blackbirds

Treesearch

Claudial Mettke-Hofmann; Pamela H. Sinclair; Paul B. Hamel; Russell Greenberg

2010-01-01

Aging birds often relies on differences in plumage between immatures and adults, and understanding these patterns can improve our ability to discern demographic patterns within populations. We investigated patterns of prebasic molt of the Rusty Blackbird (Euphagus carolinus) in fall at Whitehorse, Yukon Territory, and developed a new technique for aging based on...

Shellfish/crustacean oral allergy syndrome among national service pre-enlistees in Singapore.

PubMed

Thong, Bernard Yu-Hor; Arulanandam, Shalini; Tan, Sze-Chin; Tan, Teck-Choon; Chan, Grace Yin-Lai; Tan, Justina Wei-Lyn; Yeow, Mark Chong-Wei; Tang, Chwee-Ying; Hou, Jinfeng; Leong, Khai-Pang

2018-04-01

All Singaporean males undergo medical screening prior to compulsory military service. A history of possible food allergy may require referral to a specialist Allergy clinic to ensure that special dietary needs can be taken into account during field training and deployment. To study the pattern of food allergy among pre-enlistees who were referred to a specialist allergy clinic to work up suspected food allergy. Retrospective study of all pre-enlistees registered in the Clinical Immunology/Allergy New Case Registry referred to the Allergy Clinic from 1 August 2015 to 31 May 2016 for suspected food allergy. One hundred twenty pre-enlistees reporting food allergy symptoms other than rash alone were referred to the Allergy Clinic during the study period. Of these, 77 (64.2%) had food allergy. Among those with food allergy, mean age was 19.1 ± 1.5 years. They comprised predominantly Chinese (66.2%) and Malays (20.8%). The most commonly reported foods were shellfish/crustaceans (78%), peanut (15.6%), and egg (6.5%). Self-limiting oral allergy syndrome, OAS (itchy lips and throat with/without lip angioedema) was the most common manifestation (n = 33, 42.9%) followed by anaphylaxis (n = 23, 29.9%). Majority of OAS was from shellfish/crustacean (90.6%); of which shrimp (30.3%), crab (15.2%), and lobster (3.0%) were the most common. Mild childhood asthma (69.7%), allergic rhinitis (6.3%), and eczema (6.1%) were the most common atopic conditions among individuals with shellfish/crustacean OAS. This pattern was similar for shellfish/crustacean anaphylaxis. Skin prick tests were most commonly positive for shrimp (OAS 87.1% vs. anaphylaxis 100%), crab (OAS 95.8% vs. 90.9%), and lobster (OAS 91.7% vs. 63.6%). OAS to shellfish/crustaceans was more common than anaphylaxis among this study population of young males referred for food allergy symptoms other than rash alone.

50 CFR 665.440 - Mariana crustacean fisheries. [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Mariana crustacean fisheries. [Reserved] 665.440 Section 665.440 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC...

50 CFR 665.440 - Mariana crustacean fisheries. [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Mariana crustacean fisheries. [Reserved] 665.440 Section 665.440 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC...

50 CFR 665.240 - Hawaii crustacean fisheries. [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Hawaii crustacean fisheries. [Reserved] 665.240 Section 665.240 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC...

Plumbagin exerts an immunosuppressive effect on human T-cell acute lymphoblastic leukemia MOLT-4 cells

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

Bae, Kyoung Jun; Lee, Yura; Kim, Soon Ae

2016-04-22

Of the hematological disorders typified by poor prognoses and survival rates, T-cell acute lymphoblastic leukemia (T-ALL) is one of the most commonly diagnosed. Despite the development of new therapeutic agents, the treatment options for this cancer remain limited. In this manuscript, we investigated the anti-proliferative effects of plumbagin, mediated by the activation of mitogen-activated protein kinase (MAPK) pathways, and inhibition of NF-κB signaling; the human T-ALL MOLT-4 cell line was used as our experimental system. Plumbagin is a natural, plant derived compound, which exerts an anti-proliferative activity against many types of human cancer. Our experiments confirm that plumbagin induces a caspase-dependentmore » apoptosis of MOLT-4 cells, with no significant cytotoxicity seen for normal peripheral blood mononuclear cells (PBMCs). Plumbagin also inhibited LPS-induced phosphorylation of p65, and the transcription of NF-κB target genes. Our results now show that plumbagin is a potent inhibitor of the NF-κB signaling pathway, and suppressor of T-ALL cell proliferation. - Highlights: • Plumbagin induces caspase-dependent apoptosis in T-ALL MOLT-4 cells. • Plumbagin activates phosphorylation of stress-activated protein kinase (SAPK) JNK and p38. • Plumbagin inhibits LPS-mediated NF-κB signaling cascade. • Plumbagin inhibits LPS-mediated transcriptional activity of pro-inflammatory cytokines.« less

Life-cycle effects of single-walled carbon nanotubes (SWNTs) on an estuarine meiobenthic copepod.

PubMed

Templeton, Ryan C; Ferguson, P Lee; Washburn, Kate M; Scrivens, Wally A; Chandler, G Thomas

2006-12-01

Single-walled carbon nanotubes (SWNT) are finding increasing use in consumer electronics and structural composites. These nanomaterials and their manufacturing byproducts may eventually reach estuarine systems through wastewater discharge. The acute and chronic toxicity of SWNTs were evaluated using full life-cycle bioassays with the estuarine copepod Amphiascus tenuiremis (ASTM method E-2317-04). A synchronous cohort of naupliar larvae was assayed by culturing individual larvae to adulthood in individual 96-well microplate wells amended with SWNTs in seawater. Copepods were exposed to "as prepared" (AP) SWNTs, electrophoretically purified SWNTs, or a fluorescent fraction of nanocarbon synthetic byproducts. Copepods ingesting purified SWNTs showed no significant effects on mortality, development, and reproduction across exposures (p < 0.05). In contrast, exposure to the more complex AP-SWNT mixture significantly increased life-cycle mortality, reduced fertilization rates, and reduced molting success in the highest exposure (10 mg x L(-1)) (p < 0.05). Exposure to small fluorescent nanocarbon byproducts caused significantly increased life-cycle mortality at 10 mg x L(-1) (p < 0.05). The fluorescent nanocarbon fraction also caused significant reduction in life-cycle molting success for all exposures (p < 0.05). These results suggest size-dependent toxicity of SWNT-based nanomaterials, with the smallest synthetic byproduct fractions causing increased mortality and delayed copepod development over the concentration ranges tested.

[COMPARATIVE CHARACTERISTICS OF uNOS-POSITIVE STRUCTURES IN THE CNS OF SOME SPECIES OF CRUSTACEANS].

PubMed

Chertok, V M; Kotsyuba, E P

2015-01-01

We conducted a comparative study of NO-ergic system in the CNS of 10 species of crustaceans subclass Malacostraca, belonging to orders Stomatopoda and Decapoda, with a common habitat in Ussuri Bay (Sea of Japan). Both similar characteristics and differences in content and distribution of universal NO-synthase (uNOS) were revealed in homologous parts of the brain and ventral nerve cord of the investigated species of crustaceans. We discuss the involvement of nitric oxide in the regulation of physiological functions of decapod crustaceans and its role in the processes of adaptation to the environmental conditions.

Radiation-induced association of beta-glucuronidase with purified nuclei from irradiated MOLT-4 and HeLa cells

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

McClain, D.E.; Kalinich, J.F.; Poplack, J.K.

1989-02-01

Beta-glucuronidase, a lysosomal marker enzyme, associates with purified nuclei from HeLa and MOLT-4 cell lines in a radiation dose-dependent manner, up to 300 cGy in MOLT-4 cells, and 1000 cGy in HeLa cells. In MOLT-4 cells (200-cGy exposure), there is a significant increase in beta-glucuronidase activity detected in the nuclear fraction 24 h postirradiation with a maximum association occurring at 72 h. In HeLa cells (1000-cGy exposure), a significant association is first detected 24 h postirradiation with a maximum association at 48 h. The association is not the result of nonspecific contamination occurring during nuclei purification since nuclei from irradiatedmore » cells show no greater levels of plasma membrane marker and mitochondrial marker than controls. The nature of the association remains unclear, but activity is not removed by detergents used in the nuclei isolation procedure, and incubation of the nuclei with EDTA reverses the association only modestly. Exposure of nuclei from irradiated cells to anisotonic buffers also results in only a small decrease in beta-glucuronidase activity associated with the nuclei. These observations suggest that lysosomal hydrolases become intimately associated with the nuclei of irradiated cells.« less

50 CFR 665.640 - PRIA crustacean fisheries. [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false PRIA crustacean fisheries. [Reserved] 665.640 Section 665.640 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC Pacific Remote...

50 CFR 665.640 - PRIA crustacean fisheries. [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false PRIA crustacean fisheries. [Reserved] 665.640 Section 665.640 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC Pacific Remote...

Relation between physico-chemical limnology and crustacean community in Wular Lake of Kashmir Himalaya.

PubMed

Shah, Javaid Ahmad; Pandit, Ashok K

2013-10-01

The present study scrutinizes the seasonal variation in the distribution of crustacean zooplankton in relation to physico-chemical liminology of Wular lake. Water samples were collected from five study sites during September 2010-August 2011. Remarkable spatial and temporal variations were observed among the different study sites. Among the parameters recorded water temperature showed positive correlation with pH (p<0.01) and orthophosphate (p<0.05).Transparency showed a significant negative correlation with total alkalinity (p<0.01), free carbon dioxide (p<0.01) and ammonical nitrogen (p<0.01). Crustacean zooplankton were collected by filtering 100 L lake water through a 30 microm nytal mesh and preserved in 4% formalin. A total of 42 taxa of crustacean were recorded, among them 23 species belonged to Cladocera, 16 to Copepoda and only 3 to Ostracoda. Species diversity and density depicted an abrupt up surge on the advent of warmer period (extending from March). Among the various sites a maximum of 40 species were recorded from a single biotope (site III) against the minimum of only 17 species being recorded from site I. Bray-Curtis cluster analysis showed close similarity (0.928-0.944%) between summer and autumn in terms of species diversity. Pearson correlation coefficient of the various physico-chemical parameters of water with crustacean zooplankton depicted that not only a single but multiple factors govern over the distribution and diversity of crustacean in the lake.

Characterization of a molt-related myostatin gene (FmMstn) from the banana shrimp Fenneropenaeus merguiensis.

PubMed

Zhuo, Rui Qun; Zhou, Ting Ting; Yang, Shi Ping; Chan, Siuming Francis

2017-07-01

Myostatin is an important member of the transforming growth factor (TGF) family that functions to regulate muscle growth in animals. In this study, the myostatin gene (FmMstn) and two slightly different (short and long forms) cDNAs of the banana shrimp Fenneropenaeus merguiensis were cloned and characterized. Similar to Mstn gene of the scallop, fish and mammal, FmMstn gene consists of 3 exons and 2 introns. The 2kb upstream promoter region of the FmMstn gene consists of putative response elements for myocyte enhancing factor (MEF2) and E-box factors. The longest open reading frame of the short Mstn consists of 1260bp encoding for a protein with 420 amino acid residues. The long FmMstn is almost identical to the short FmMstn with the exception of 8 amino acid insertions. FmMstn is most similar to the Mstn of Litopenaeus vannamei and Penaeus monodon sharing >92-98% amino acid sequence identity. Multiple sequence alignment results revealed high degree of amino acid conservation of the cysteine residues and mature peptide of the FmMstn with Mstn from other animals. FmMstn transcript was detected in the heart, muscle, optic nerve and thoracic ganglion. FmMstn transcript level in muscle is higher in early postmolt, decreases in intermolt and increases again towards ecdysis. Higher expression level of FmMstn is also observed in smaller shrimp of the same age. Knock-down of FmMstn gene by RNAi can cause a significant increase in molt cycle duration and failure of some shrimp to undergo ecdysis. Direct DNA sequencing results revealed that FmMstn gene is highly polymorphic and several potential SNPs have been identified. Some SNPs are associated with the size difference of the shrimp. In summary, the result of this study indicates that shrimp FmMstn gene is molt/growth-related and the presence of SNP suggests that it could be a candidate gene for shrimp genetic improvement research. Copyright © 2017. Published by Elsevier Inc.

Consumption of crustaceans by megaherbivorous dinosaurs: dietary flexibility and dinosaur life history strategies.

PubMed

Chin, Karen; Feldmann, Rodney M; Tashman, Jessica N

2017-09-21

Large plant-eating dinosaurs are usually presumed to have been strictly herbivorous, because their derived teeth and jaws were capable of processing fibrous plant foods. This inferred feeding behavior offers a generalized view of dinosaur food habits, but rare direct fossil evidence of diet provides more nuanced insights into feeding behavior. Here we describe fossilized feces (coprolites) that demonstrate recurring consumption of crustaceans and rotted wood by large Late Cretaceous dinosaurs. These multi-liter coprolites from the Kaiparowits Formation are primarily composed of comminuted conifer wood tissues that were fungally degraded before ingestion. Thick fragments of laminar crustacean cuticle are scattered within the coprolite contents and suggest that the dinosaurian defecators consumed sizeable crustaceans that sheltered in rotting logs. The diet of decayed wood and crustaceans offered a substantial supply of plant polysaccharides, with added dividends of animal protein and calcium. Nevertheless, it is unlikely that the fossilized fecal residues depict year-round feeding habits. It is more reasonable to infer that these coprolites reflected seasonal dietary shifts-possibly related to the dinosaurs' oviparous breeding activities. This surprising fossil evidence challenges conventional notions of herbivorous dinosaur diets and reveals a degree of dietary flexibility that is consistent with that of extant herbivorous birds.

Proecdysial changes in serum ecdysone titers, gastrolith formation, and limb regeneration following molt induction by limb autotomy and/or eyestalk removal in the land crab, Gecarcinus lateralis

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

McCarthy, J.F.; Skinner, D.M.

1977-01-01

The changes in serum ecdysone titers, gastrolith deposition, and limb regeneration were monitored at each stage of the molt cycle in the land crab, Gecarcinus lateralis. Animals were induced to molt by multiple-limb autotomy or eyestalk removal. The presence of ..cap alpha..-ecdysone and b-ecdysone (20-hydroxyecdysone) in the animals' serum was demonstrated chromatographically. ..beta..-ecdysone was the major circulating ecdysone, while ..cap alpha..-ecdysone was present only at very low concentrations. Four other components reacting with the ecdysone antiserum were separated chromatographically; one of these, a nonpolar compound, became a major component of the serum ecdysones at the time of maximum hormone titers.more » Ecdysone titers in the serum remained at the level characteristic of intermolt (approximately 10 ng/ml) during basal regeneration and rose linearly during the premolt period, reaching a maximum when regeneration of limbs had ceased and exoskeleton was deposited. Ecdysone decreased during stages D/sub 3/ and D/sub 4/, approaching intermolt levels at the time of ecdysis, where they remained through postmolt stages A and B. The patterns of premolt changes in ecdysone titers, gastroliths, and regeneration were very similar in ''normal'' animals (stimulated to molt by the loss of eight pereiopods) and in animals without eyestalks; however, in crabs without eyestalks, the changes were completed in about half the time as in crabs with eyestalks. Basal regeneration is associated with low ecdysone levels even in crabs without eyestalks. The normal sequence of proecdysial events is not initiated until the completion of basal regeneration. It is suggested that there exists a yet-unidentified mechanism outside the eyestalk capable of preventing increases in ecdysone titers while limbs engage in basal regeneration.« less

Phylogenetic position of the pentastomida and [pan]crustacean relationships

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

Lavrov, Dennis V.; Brown, Wesley M.; Boore, Jeffrey L.

2004-01-31

Pentastomids are a small group of vermiform animals with unique morphology and parasitic lifestyle. They are generally recognized as being related to the Arthropoda, however the nature of this relationship is controversial. We have determined the complete sequence of the mitochondrial DNA (mtDNA) of the pentastomid Armillifer armillatus and complete, or nearly complete, mtDNA sequences from representatives of four previously unsampled groups of Crustacea: Remipedia (Speleonectes tulumensis), Cephalocarida (Hutchinsoniella macracantha), Cirripedia (Pollicipes polymerus), and Branchiura (Argulus americanus). Analyses of the mtDNA gene arrangements and sequences determined in this study indicate unambiguously that pentastomids are a group of modified crustaceans likelymore » related to branchiurans. In addition, gene arrangement comparisons strongly support an unforeseen assemblage of pentastomids with maxillopod and cephalocarid crustaceans, to the exclusion of remipedes, branchiopods, malacos tracans and insects.« less

The crustacean eye: dark/light adaptation, polarization sensitivity, flicker fusion frequency, and photoreceptor damage.

PubMed

Meyer-Rochow, V B

2001-12-01

Compound eyes, nauplius eyes, frontal organs, intracerebral ocelli, and caudal photoreceptors are the main light and darkness detectors in crustaceans, but they need not be present all at once in an individual and in some crustaceans no photoreceptors whatsoever are known. Compound eye designs reflect on their functions and have evolved to allow the eye to operate optimally under a variety of environmental conditions. Dark-light-adaptational changes manifest themselves in pigment granule translocations, cell movements, and optical adjustments which fine-tune an eye's performance to rapid and unpredictable fluctuations in ambient light intensities as well as to the slower and predictable light level changes associated with day and night oscillations. Recycling of photoreceptive membrane and light-induced membrane collapse are superficially similar events that involve the transduction cascade, intracellular calcium, and membrane fatty acid composition, but which differ in aetiology and longterm consequence. Responses to intermittant illumination and linearly polarized light evoke in the eye of many crustaceans characteristic responses that appear to be attuned to each species' special needs. How the visual responses are processed more centrally and to what extent a crustacean makes behavioural use of e-vector discrimination and flickering lights are questions, however, that still have not been satisfactorily answered for the vast majority of all crustacean species. The degree of light-induced photoreceptor damage depends on a large number of variables, but once manifest, it tends to be progressive and irreversible. Concomittant temperature stress aggravates the situation and there is evidence that free radicals and lipid hydroperoxides are involved.

Effects of thyroid hormone manipulation on pre-nuptial molt, luteinizing hormone and testicular growth in male white-crowned sparrows (Zonotrichia leuchophrys gambelii).

PubMed

Pérez, Jonathan H; Meddle, Simone L; Wingfield, John C; Ramenofsky, Marilyn

2018-01-01

Most seasonal species rely on the annual change in day length as the primary cue to appropriately time major spring events such as pre-nuptial molt and breeding. Thyroid hormones are thought to be involved in the regulation of both of these spring life history stages. Here we investigated the effects of chemical inhibition of thyroid hormone production using methimazole, subsequently coupled with either triiodothyronine (T3) or thyroxine (T4) replacement, on the photostimulation of pre-nuptial molt and breeding in Gambel's white-crowned sparrows (Zonotrichia leuchophrys gambelii). Suppression of thyroid hormones completely prevented pre-nuptial molt, while both T3 and T4 treatment restored normal patterns of molt in thyroid hormone-suppressed birds. Testicular recrudescence was blocked by methimazole, and restored by T4 but not T3, in contrast to previous findings demonstrating central action of T3 in the photostimulation of breeding. Methimazole and replacement treatments elevated plasma luteinizing hormone levels compared to controls. These data are partially consistent with existing theories on the role of thyroid hormones in the photostimulation of breeding, while highlighting the possibility of additional feedback pathways. Thus we suggest that regulation of the hypothalamic pituitary gonad axis that controls breeding may be more complex than previously considered. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Shellfish/crustacean oral allergy syndrome among national service pre-enlistees in Singapore

PubMed Central

Arulanandam, Shalini; Tan, Sze-Chin; Tan, Teck-Choon; Chan, Grace Yin-Lai; Tan, Justina Wei-Lyn; Yeow, Mark Chong-Wei; Tang, Chwee-Ying; Hou, Jinfeng; Leong, Khai-Pang

2018-01-01

Background All Singaporean males undergo medical screening prior to compulsory military service. A history of possible food allergy may require referral to a specialist Allergy clinic to ensure that special dietary needs can be taken into account during field training and deployment. Objective To study the pattern of food allergy among pre-enlistees who were referred to a specialist allergy clinic to work up suspected food allergy. Methods Retrospective study of all pre-enlistees registered in the Clinical Immunology/Allergy New Case Registry referred to the Allergy Clinic from 1 August 2015 to 31 May 2016 for suspected food allergy. Results One hundred twenty pre-enlistees reporting food allergy symptoms other than rash alone were referred to the Allergy Clinic during the study period. Of these, 77 (64.2%) had food allergy. Among those with food allergy, mean age was 19.1 ± 1.5 years. They comprised predominantly Chinese (66.2%) and Malays (20.8%). The most commonly reported foods were shellfish/crustaceans (78%), peanut (15.6%), and egg (6.5%). Self-limiting oral allergy syndrome, OAS (itchy lips and throat with/without lip angioedema) was the most common manifestation (n = 33, 42.9%) followed by anaphylaxis (n = 23, 29.9%). Majority of OAS was from shellfish/crustacean (90.6%); of which shrimp (30.3%), crab (15.2%), and lobster (3.0%) were the most common. Mild childhood asthma (69.7%), allergic rhinitis (6.3%), and eczema (6.1%) were the most common atopic conditions among individuals with shellfish/crustacean OAS. This pattern was similar for shellfish/crustacean anaphylaxis. Skin prick tests were most commonly positive for shrimp (OAS 87.1% vs. anaphylaxis 100%), crab (OAS 95.8% vs. 90.9%), and lobster (OAS 91.7% vs. 63.6%). Conclusion OAS to shellfish/crustaceans was more common than anaphylaxis among this study population of young males referred for food allergy symptoms other than rash alone. PMID:29732294

Risk of Vibrio transmission linked to the consumption of crustaceans in coastal towns of Côte d'Ivoire.

PubMed

Traoré, S G; Bonfoh, B; Krabi, R; Odermatt, P; Utzinger, J; Rose, K-N; Tanner, M; Frey, J; Quilici, M-L; Koussémon, M

2012-06-01

The purpose of this study was to assess the risk of Vibrio spp. transmission from crustaceans to humans in two coastal towns of Côte d'Ivoire. Bacteriologic analysis was performed on 322 crustacean samples obtained from six markets in Abidjan and one in Dabou. Suspected Vibrio colonies were identified by morphological, cultural, biochemical, and molecular tests and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. PCR assays were used to further characterize Vibrio strains. A survey on consumption of crustaceans was conducted among 120 randomly selected households in Abidjan. Overall, Vibrio spp. were isolated from 7.8% of the crustacean samples studied, at levels as high as 6.3 log CFU/g. Of the Vibrio strains identified, 40% were V. alginolyticus, 36% were V. parahaemolyticus, and 24% were nontoxigenic V. cholerae; the latter two species can cause mild to severe forms of seafood-associated gastroenteritis. Among interviewed households, 11.7% reported daily consumption of crustaceans, confirming the high probability of exposure of human population to Vibrio spp., and 7.5% reported symptoms of food poisoning after consumption of crustaceans. The absence of genes encoding major virulence factors in the studied strains, i.e., cholera toxin (ctxA and ctxB) in V. cholerae and thermostable direct hemolysin (tdh) and thermostable direct hemolysin-related hemolysin (trh) in V. parahaemolyticus, does not exclude the possibility of exposure to pathogenic strains. However, human infections are not common because most households (96.7%) boil crustaceans, usually for at least 45 min (85.9% of households) before consumption.

Progesterone inhibits the in vitro L3/L4 molting process in Haemonchus contortus.

PubMed

Gutiérrez-Amézquita, R A; Morales-Montor, J; Muñoz-Guzmán, M A; Nava-Castro, K E; Ramírez-Álvarez, H; Cuenca-Verde, C; Moreno-Mendoza, N A; Cuéllar-Ordaz, J A; Alba-Hurtado, F

2017-12-15

We evaluated the direct effects of progesterone on the morphology, maturation and behavior of Haemonchus contortus larvae in vitro. The presence and location of possible progesterone receptors in these larvae were also determined. The addition of 8ng/mL of progesterone to larval cultures over 10days reduced larval enlargement, while the addition of 160ng/mL of the hormone increased the enlargement. Up to 62% and 65% of the H. contortus larvae molted from third-stage larvae (L3) to fourth-stage larvae (L4) when cultured in RPMI-1640 media without hormone for 5 and 10days, respectively. The addition of different progesterone concentrations (1, 8, 16, 80 and 160ng/mL) to the larval cultures significantly inhibited the molting process within the same periods. The addition of 8ng/mL or higher progesterone concentrations to the cultures significantly increased larval motility (p<0.05) compared with unstimulated larvae. Flow cytometry showed the expression of progesterone receptors (P4-R) in 15% of the cells from newly isolated H. contortus larvae. When the larvae were cultured for 5days in the presence of the hormone, the percentage of P 4 -R+ cells remained the same. In contrast, unstimulated larvae showed a significant reduction in the number of P 4 -R+ cells. Using confocal microscopy, a greater concentration of P 4 -Rs was immunolocated in the anterior portion of the alimentary tract of the larvae, suggesting that the cells in this region are targeted by the hormone. The results of the present study show that H. contortus larvae have possible P 4 -Rs and respond to this hormone by inhibiting their molting process, thereby suggesting the participation of progesterone in the larval arrest phenomenon. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative toxicology for risk assessment of marine fishes and crustaceans. [Cyprinodon variegatus

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

Suter, G.W. II; Rosen, A.E.

1988-05-01

The goal of this study was to collect data on the effects of chemicals on marine fishes and crustaceans and to evaluate the predictive power of the data for assessing risks to marine resources. The data sets consisted of acute median lethal concentrations (LC{sub 50s}) and chronic maximum acceptable toxicant concentrations (MATCs). They were analyzed with regression models and simple comparisons. The conclusions include the following: (1) the variability found in the marine data was comparable to that found in freshwater data; (2) the standard marine test fish Cyprinodon variegatus appears to be representative of marine fishes; (3) the responsesmore » of marine crustaceans are so highly diverse that the concept of a representative crustacean is questionable; (4) mysid and penaeid shrimp appear to be particularly sensitive to toxic chemicals. These conclusions are subject to the constraints of the existing limited data base and should be confirmed by a systematic study of the relative sensitivity of marine organisms to chemicals with diverse modes of action.« less

Evaluation of limit feeding varying levels of distillers dried grains with solubles in non-feed-withdrawal molt programs for laying hens.

PubMed

Mejia, L; Meyer, E T; Studer, D L; Utterback, P L; Utterback, C W; Parsons, C M; Koelkebeck, K W

2011-02-01

An experiment was conducted with 672 Hy-Line W-36 Single Comb White Leghorn hens (69 wk of age) to evaluate the effects of feeding varying levels of corn distillers dried grains with solubles (DDGS) with corn, wheat middlings, and soybean hulls on long-term laying hen postmolt performance. The control molt treatment consisted of a 47% corn:47% soybean hulls (C:SH) diet fed ad libitum for 28 d. Hens fed the other 7 treatments were limit fed 65 g/hen per day for 16 d, and then fed 55 g/hen per day for 12 d. Hens on treatments 2 and 3 were fed 49% C:35% wheat middlings (WM) or SH:10% DDGS diets (C:WM:10DDGS, C:SH:10DDGS). Hens on treatments 4 and 5 were fed 49% C:25% WM or SH:20% DDGS diets (C:WM:20DDGS, C:SH:20DDGS). Those on treatments 6 and 7 were fed 47% C:47% DDGS (C:DDGS) or 47% WM:47% DDGS (WM:DDGS) diets. Those on treatment 8 were fed a 94% DDGS diet. At 28 d, all hens were fed a corn-soybean meal layer diet (16% CP) and production performance was measured for 36 wk. None of the hens fed the molt diets went completely out of production, and only the C:SH and C:SH:10DDGS molt diets decreased hen-day egg production to below 5% by wk 4 of the molt period. Postmolt egg production was lowest (P < 0.05) for the C:WM:20DDGS treatment. No differences (P > 0.05) in egg weights were detected among treatments throughout the postmolt period. In addition, no consistent differences were observed among treatments for egg mass throughout the postmolt period. Overall results of this study indicated that limit feeding diets containing DDGS at levels of 65 or 55 g/hen per day during the molt period did not cause hens to totally cease egg production.

Conservation of structure, signaling and pharmacology between two serotonin receptor subtypes from decapod crustaceans, Panulirus interruptus and Procambarus clarkii.

PubMed

Spitzer, Nadja; Edwards, Donald H; Baro, Deborah J

2008-01-01

Serotonin (5-HT) plays important roles in the maintenance and modulation of neural systems throughout the animal kingdom. The actions of 5-HT have been well characterized for several crustacean model circuits; however, a dissection of the serotonergic transduction cascades operating in these models has been hampered by the lack of pharmacological tools for invertebrate receptors. Here we provide pharmacological profiles for two 5-HT receptors from the swamp crayfish, Procambarus clarkii: 5-HT(2beta) and 5-HT(1alpha). In so doing, we also report the first functional expression of a crustacean 5-HT(1) receptor, and show that it inhibits accumulation of cAMP. The drugs mCPP and quipazine are 5-HT(1alpha) agonists and are ineffective at 5-HT(2beta). Conversely, methiothepin and cinanserin are antagonists of 5-HT(2beta) but do not block 5-HT(1alpha). A comparison of these two receptors with their orthologs from the California spiny lobster, Panulirus interruptus, indicates conservation of protein structure, signaling and pharmacology. This conservation extends beyond crustacean infraorders. The signature residues that form the ligand-binding pocket in mammalian 5-HT receptors are found in the crustacean receptors. Similarly, the protein domains involved in G protein coupling are conserved between the two crustacean receptors and other characterized arthropod and mammalian 5-HT receptors. Considering the apparent conservation of pharmacological properties between crustacean 5-HT receptors, these tools could be applicable to related crustacean physiological preparations.

Comparison of fatty acid, cholesterol, vitamin A and E composition, and trans fats in eggs from brown and white egg strains that were molted or nonmolted.

PubMed

Anderson, Kenneth E

2013-12-01

The impact of egg color, hen strain, and molting on the nutritional composition of eggs is limited. Therefore, this study compared nutritional composition and component percentages of cage-produced shell eggs with respect to egg color, hen strain, and molt. Four strains were selected from the North Carolina Layer Performance and Management Test: Hy-Line Brown (HB) and Bovans Brown (BB), and Hy-Line W-36 (HW) and Bovans White (BovW) were selected. Two groups from each strain were selected and 2 groups of molted HW and BovW were selected and compared with their nonmolted counterparts to examine the molt's impact. Two sets of eggs from each replicate were collected simultaneously at 101 wk of age. One sample of eggs was broken into a 12-egg pool stomached for 3 min (n = 12 samples), then divided into six 50-mL tubes, sealed, and frozen to be sent for cholesterol, n-3 fatty acids, saturated fat, monounsaturated fats, polyunsaturated fats, β-carotene, vitamin A, and vitamin E analyses. The other set of 12 eggs was then assessed for component percentages. The HW eggs had a greater (P < 0.05) percentage of yolk than the BovW eggs of 28.12 versus 27.00%, respectively; however, the BovW eggs had 1.0% more albumen. The HB and BB egg components were not different. Brown eggs were heavier (P < 0.01) than white eggs. White eggs had greater (P < 0.0001) percent yolk and the brown eggs had greater (P < 0.0001) percent albumen. The eggs from molted hens had a greater (P < 0.001) percent shell. Total fat content in the samples was (P < 0.05) higher in white eggs by 0.70% than brown eggs due to increased saturated and polyunsaturated fats. The molting of hens reduced (P < 0.01) saturated fats by 0.21% in the egg. Vitamin A levels were higher (P < 0.0001) in white eggs, and vitamin E was higher (P < 0.0001) in brown eggs. Strain and molt appear to influence nutrient composition and component percentages in eggs produced from laying hens.

50 CFR 665.140 - American Samoa Crustacean Fisheries. [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false American Samoa Crustacean Fisheries. [Reserved] 665.140 Section 665.140 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN...

50 CFR 665.140 - American Samoa Crustacean Fisheries. [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false American Samoa Crustacean Fisheries. [Reserved] 665.140 Section 665.140 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN...

Qualitative and quantitative changes in exoskeletal proteins synthesized throughout the molt cycle of the Bermuda land crab

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

Stringfellow, L.A.; Skinner, D.M.

1987-05-01

During the premolt period in Crustacea, a single layer of epidermal cells that underlies the exoskeleton is thought to be responsible for the degradation of the old exoskeleton and synthesis of a new one. In order to identify molt-specific proteins and their temporal appearance, they cultured epidermis and associated integumentary tissue from the gill chambers of crab in vitro in the presence of one of three radiolabeled amino acids. Autoradiographs of (/sup 35/S)Met-labeled tissues indicate a low level of synthesis in epidermal cells of intermolt animals; synthesis increases during premolt and stage B of postmolt. Label is also found inmore » the innermost layer of the old exoskeleton while it is being degraded and in new exoskeletal layers during their synthesis. Fluorographs of gels of integumentary proteins show marked quantitative changes in 44 and 56 kD proteins late in premolt. Qualitative changes include synthesis of 46 and 48 kD proteins during late premolt and three proteins (all of approx. 170 kD) detectable only in postmolt. Solubilized gel slices of (/sup 3/H)Leu-labeled proteins indicate maximum synthesis at an earlier premolt stage than seen in Met-labeled proteins. Other proteins of 20, 24, 29, 32, and 96 kD are synthesized in a stage-dependent manner while (/sup 3/H)Tyr labels small proteins that appear only in late premolt.« less

50 CFR 16.13 - Importation of live or dead fish, mollusks, and crustaceans, or their eggs.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., and crustaceans, or their eggs. 16.13 Section 16.13 Wildlife and Fisheries UNITED STATES FISH AND... Wildlife § 16.13 Importation of live or dead fish, mollusks, and crustaceans, or their eggs. (a) Upon an... their gametes or fertilized eggs, may be imported, transported, and possessed in captivity without a...

The ovary structure and oogenesis in the basal crustaceans and hexapods. Possible phylogenetic significance.

PubMed

Jaglarz, Mariusz K; Kubrakiewicz, Janusz; Bilinski, Szczepan M

2014-07-01

Recent large-scale phylogenetic analyses of exclusively molecular or combined molecular and morphological characters support a close relationship between Crustacea and Hexapoda. The growing consensus on this phylogenetic link is reflected in uniting both taxa under the name Pancrustacea or Tetraconata. Several recent molecular phylogenies have also indicated that the monophyletic hexapods should be nested within paraphyletic crustaceans. However, it is still contentious exactly which crustacean taxon is the sister group to Hexapoda. Among the favored candidates are Branchiopoda, Malacostraca, Remipedia and Xenocarida (Remipedia + Cephalocarida). In this context, we review morphological and ultrastructural features of the ovary architecture and oogenesis in these crustacean groups in search of traits potentially suitable for phylogenetic considerations. We have identified a suite of morphological characters which may prove useful in further comparative studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

A structure-function analysis of ion transport in crustacean gills and excretory organs.

PubMed

Freire, Carolina A; Onken, Horst; McNamara, John C

2008-11-01

Osmotic and ionic regulation in the Crustacea is mostly accomplished by the multifunctional gills, together with the excretory organs. In addition to their role in gas exchange, the gills constitute organs of active, transepithelial, ion transport, an activity of major importance that underlies many essential physiological functions like osmoregulation, calcium homeostasis, ammonium excretion and extracellular pH regulation. This review focuses on structure-function relationships in crustacean gills and excretory effectors, from the organ to molecular levels of organization. We address the diversity of structural architectures encountered in different crustacean gill types, and in constituent cell types, before examining the physiological mechanisms of Na(+), Cl(-), Ca(2+) and NH(4)(+) transport, and of acid-base equivalents, based on findings obtained over the last two decades employing advanced techniques. The antennal and maxillary glands constitute the principal crustacean excretory organs, which have received less attention in functional studies. We examine the diversity present in antennal and maxillary gland architecture, highlighting the structural similarities between both organ types, and we analyze the functions ascribed to each glandular segment. Emphasis is given to volume and osmoregulatory functions, capacity to produce dilute urine in freshwater crustaceans, and the effect of acclimation salinity on urine volume and composition. The microanatomy and diversity of function ascribed to gills and excretory organs are appraised from an evolutionary perspective, and suggestions made as to future avenues of investigation that may elucidate evolutionary and adaptive trends underpinning the invasion and exploitation of novel habitats.

Reef-associated crustacean fauna: biodiversity estimates using semi-quantitative sampling and DNA barcoding

NASA Astrophysics Data System (ADS)

Plaisance, L.; Knowlton, N.; Paulay, G.; Meyer, C.

2009-12-01

The cryptofauna associated with coral reefs accounts for a major part of the biodiversity in these ecosystems but has been largely overlooked in biodiversity estimates because the organisms are hard to collect and identify. We combine a semi-quantitative sampling design and a DNA barcoding approach to provide metrics for the diversity of reef-associated crustacean. Twenty-two similar-sized dead heads of Pocillopora were sampled at 10 m depth from five central Pacific Ocean localities (four atolls in the Northern Line Islands and in Moorea, French Polynesia). All crustaceans were removed, and partial cytochrome oxidase subunit I was sequenced from 403 individuals, yielding 135 distinct taxa using a species-level criterion of 5% similarity. Most crustacean species were rare; 44% of the OTUs were represented by a single individual, and an additional 33% were represented by several specimens found only in one of the five localities. The Northern Line Islands and Moorea shared only 11 OTUs. Total numbers estimated by species richness statistics (Chao1 and ACE) suggest at least 90 species of crustaceans in Moorea and 150 in the Northern Line Islands for this habitat type. However, rarefaction curves for each region failed to approach an asymptote, and Chao1 and ACE estimators did not stabilize after sampling eight heads in Moorea, so even these diversity figures are underestimates. Nevertheless, even this modest sampling effort from a very limited habitat resulted in surprisingly high species numbers.

PHOTOINDUCED TOXICITY OF FLUORANTHENE TO SEVEN MARINE BENTHIC CRUSTACEANS

EPA Science Inventory

Seven marine benthic crustaceans were exposed in 4 d water-only toxicity tests to five concentrations of fluoranthene.After exposures, mortality (LC50) and the ability to bury in clean sediment (EC50) were determined. Survivors were then exposed to UV radiation for 1 h. The diffe...

Occurrence and molecular characterisation of Vibrio parahaemolyticus in crustaceans commercialised in Venice area, Italy.

PubMed

Caburlotto, Greta; Suffredini, Elisabetta; Toson, Marica; Fasolato, Luca; Antonetti, Paolo; Zambon, Michela; Manfrin, Amedeo

2016-03-02

Infections due to the pathogenic human vibrios, Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus, are mainly associated with consumption of raw or partially cooked bivalve molluscs. At present, little is known about the presence of Vibrio species in crustaceans and the risk of vibriosis associated with the consumption of these products. The aim of the present study was to evaluate the prevalence and concentration of the main pathogenic Vibrio spp. in samples of crustaceans (n=143) commonly eaten in Italy, taking into account the effects of different variables such as crustacean species, storage conditions and geographic origin. Subsequently, the potential pathogenicity of V. parahaemolyticus strains isolated from crustaceans (n=88) was investigated, considering the classic virulence factors (tdh and trh genes) and four genes coding for relevant proteins of the type III secretion systems 2 (T3SS2α and T3SS2β). In this study, the presence of V. cholerae and V. vulnificus was never detected, whereas 40 samples (28%) were positive for V. parahaemolyticus with an overall prevalence of 41% in refrigerated products and 8% in frozen products. The highest prevalence and average contamination levels were detected in Crangon crangon (prevalence 58% and median value 3400 MPN/g) and in products from the northern Adriatic Sea (35%), with the samples from the northern Venetian Lagoon reaching a median value of 1375 MPN/g. While genetic analysis confirmed absence of the tdh gene, three of the isolates contained the trh gene and, simultaneously, the T3SS2β genes. Moreover three possibly clonal tdh-negative/trh-negative isolates carried the T3SS2α apparatus. The detection of both T3SS2α and T3SS2β apparatuses in V. parahaemolyticus strains isolated from crustaceans emphasised the importance of considering new genetic markers associated with virulence besides the classical factors. Moreover this study represents the first report dealing with Vibrio spp. in

Reference intervals for serum biochemistries of molting Pacific Black Brant (Branta bernicla nigricans) in Northern Alaska, USA

USGS Publications Warehouse

Franson, J. Christian; Flint, Paul L.; Schmutz, Joel A.

2017-01-01

We determined reference intervals for nine serum biochemistries in samples from 329 molting, after-hatch-year, Pacific Black Brant (Branta bernicla nigricans) in Alaska, US. Cholesterol and nonesterified fatty acids differed by sex, but no other differences were noted.

Crustaceans from a tropical estuarine sand-mud flat, Pacific, Costa Rica, (1984-1988) revisited.

PubMed

Vargas-Zamora, José A; Sibaja-Cordero, Jeffrey A; Vargas-Castillo, Rita

2012-12-01

The availability of data sets for time periods of more than a year is scarce for tropical environments. Advances in hardware and software speed-up the re-analysis of old data sets and facilitates the description of population oscillations. Using recent taxonomic literature and software we have updated and re-analized the information on crustacean diversity and population fluctuations from a set of cores collected at a mud-sand flat in the mid upper Gulf of Nicoya estuary, Pacific coast of Costa Rica (1984-1988). A total of 112 morphological species of macroinvertebrates was found, of which 29 were crustaceans. Taxonomic problems, maily with the peracarids, prevented the identification of a group of species. The abundance patterns of the crab Pinnixa valerii, the ostracod Cyprideis pacifica, and the cumacean Coricuma nicoyensis were analized with the Generalized Additive Models of the free software R. The models evidenced a variety of population oscillations during the sampling period. These oscillations probably included perturbations induced by external factors, like the strong red tide events of 1985. In additon, early on 1984 the populations might have been at an altered state due to the inpact of El Niño 1982-83. Thus, the oscillations observed during the study period departed from the expected seasonality (dry vs rainy) pattern and are thus considered atypical for this tropical estuarine tidal-flat. Crustacean diversity and population peaks were within the range of examples found in worldwide literature. However, abundances of the cumacean C. nicoyensis, an endemic species, are the highest reported for a tropical estuary. Comparative data from tropical tidal flat crustaceans continues to be scarce. Crustaceans (total vs groups) had population changes in response to the deployment of predator exclusion cages during the dry and rainy seasons of 1985. Temporal and spatial patchiness characterized the abundances of P. valeri, C. pacifica and C. nicoyenis.

C. elegans Notch signaling regulates adult chemosensory response and larval molting quiescence

PubMed Central

Singh, Komudi; Chao, Michael Y.; Somers, Gerard A.; Komatsu, Hidetoshi; Corkins, Mark E.; Larkins-Ford, Jonah; Tucey, Tim; Dionne, Heather M.; Walsh, Melissa B.; Beaumont, Emma K.; Hart, Douglas P.; Lockery, Shawn; Hart, Anne C.

2011-01-01

Summary Background The conserved DOS motif proteins OSM-7 and OSM-11 function as co-ligands with canonical DSL ligands to activate C. elegans Notch receptors during development. We report herein that Notch ligands, co-ligands and the receptors LIN-12 and GLP-1 regulate two C. elegans behaviors: chemosensory avoidance of octanol and quiescence during molting lethargus. Results C. elegans lacking osm-7 or osm-11 are defective in their response to octanol. We find that OSM-11 is secreted from hypodermal seam cells into the pseudocoelomic body cavity and acts non-cell autonomously as a diffusible factor. OSM-11 acts with the DSL ligand LAG-2 to activate LIN-12 and GLP-1 Notch receptors in the neurons of adult animals,- thereby regulating octanol avoidance response. In adult animals, over-expression of osm-11 and consequent Notch receptor activation induces anachronistic sleep-like quiescence. Perturbation of Notch signaling altered basal activity in adults as well as arousal thresholds and quiescence during molting lethargus. Genetic epistasis studies revealed that Notch signaling regulates quiescence via previously identified circuits and genetic pathways including the egl-4 cGMP-dependent kinase. Conclusions Our findings indicate that the conserved Notch pathway modulates behavior in adult C. elegans in response to environmental stress. Additionally, Notch signaling regulates sleep-like quiescence in C. elegans suggesting Notch may regulate sleep in other species. PMID:21549604

Horizontal transfer of transposons between and within crustaceans and insects

PubMed Central

2014-01-01

Background Horizontal transfer of transposable elements (HTT) is increasingly appreciated as an important source of genome and species evolution in eukaryotes. However, our understanding of HTT dynamics is still poor in eukaryotes because the diversity of species for which whole genome sequences are available is biased and does not reflect the global eukaryote diversity. Results In this study we characterized two Mariner transposable elements (TEs) in the genome of several terrestrial crustacean isopods, a group of animals particularly underrepresented in genome databases. The two elements have a patchy distribution in the arthropod tree and they are highly similar (>93% over the entire length of the element) to insect TEs (Diptera and Hymenoptera), some of which were previously described in Ceratitis rosa (Crmar2) and Drosophila biarmipes (Mariner-5_Dbi). In addition, phylogenetic analyses and comparisons of TE versus orthologous gene distances at various phylogenetic levels revealed that the taxonomic distribution of the two elements is incompatible with vertical inheritance. Conclusions We conclude that the two Mariner TEs each underwent at least three HTT events. Both elements were transferred once between isopod crustaceans and insects and at least once between isopod crustacean species. Crmar2 was also transferred between tephritid and drosophilid flies and Mariner-5 underwent HT between hymenopterans and dipterans. We demonstrate that these various HTTs took place recently (most likely within the last 3 million years), and propose iridoviruses and/or Wolbachia endosymbionts as potential vectors of these transfers. PMID:24472097

Horizontal transfer of transposons between and within crustaceans and insects.

PubMed

Dupeyron, Mathilde; Leclercq, Sébastien; Cerveau, Nicolas; Bouchon, Didier; Gilbert, Clément

2014-01-29

Horizontal transfer of transposable elements (HTT) is increasingly appreciated as an important source of genome and species evolution in eukaryotes. However, our understanding of HTT dynamics is still poor in eukaryotes because the diversity of species for which whole genome sequences are available is biased and does not reflect the global eukaryote diversity. In this study we characterized two Mariner transposable elements (TEs) in the genome of several terrestrial crustacean isopods, a group of animals particularly underrepresented in genome databases. The two elements have a patchy distribution in the arthropod tree and they are highly similar (>93% over the entire length of the element) to insect TEs (Diptera and Hymenoptera), some of which were previously described in Ceratitis rosa (Crmar2) and Drosophila biarmipes (Mariner-5_Dbi). In addition, phylogenetic analyses and comparisons of TE versus orthologous gene distances at various phylogenetic levels revealed that the taxonomic distribution of the two elements is incompatible with vertical inheritance. We conclude that the two Mariner TEs each underwent at least three HTT events. Both elements were transferred once between isopod crustaceans and insects and at least once between isopod crustacean species. Crmar2 was also transferred between tephritid and drosophilid flies and Mariner-5 underwent HT between hymenopterans and dipterans. We demonstrate that these various HTTs took place recently (most likely within the last 3 million years), and propose iridoviruses and/or Wolbachia endosymbionts as potential vectors of these transfers.

Eccentric preformative molt in the spotted Towhee

DOE PAGES

Fettig, Stephen M.; Hathcock, Charles Dean

2016-11-04

Examination of wing-feather molt often provides information essential for aging birds in the hand (Mulvihill 1993, pyle 1997b, 2008). Correctly aging birds is important for understanding the causal relationships between age-class survival rates and population changes (DeSante et al. 2005). For example, correctly aging birds facilitates understanding of climate effects on reproduction better than merely moni- toring population numbers because reproduction varies widely with annual weather patterns (DeSante and O’grady 2000). Age-class information can also provide a clear measure of habitat quality without confounding effects such as population sources and sinks (Van horne 1983) or misleading habitat-quality information based onmore » relative abundance or population size (pulliam 1988). Changes in bird populations often lag changes in the survival rate of an age class, while environmental changes often affect one age class immediately or after a short lag (Temple and Wiens 1989)« less

Changes in ecdysteroid levels and expression patterns of ecdysteroid-responsive factors and neuropeptide hormones during the embryogenesis of the blue crab, Callinectes sapidus.

PubMed

Techa, Sirinart; Alvarez, Javier V; Sook Chung, J

2015-04-01

Embryogenesis requires the involvement and coordination of multiple networks of various genes, according to a timeline governing development. Crustacean embryogenesis usually includes the first molt, a process that is known to be positively controlled by ecdysteroids. We determined the amounts of ecdysteroids, as well as other related factors: the ecdysone receptor (CasEcR), the retinoid X receptor (CasRXR), the molt-inhibiting hormone (CasMIH), and crustacean hyperglycemic hormone (CasCHH) during the ovarian and embryonic developments of Callinectes sapidus. In summary, the ovaries at stages 1-4 have expression levels of maternal CasEcR and CasRXR 10-50 times higher than levels seen in embryos at the yolk stage. This large difference in the amount of the these factors in C. sapidus ovaries suggests that these maternal ecdysteroid-responsive factors may be utilized at the initiation of embryogenesis. During embryogenesis, the changes in total ecdysteroids and levels of CasEcR and CasRXR expression are similar to those observed in juvenile molts. The full-length cDNA sequence of the C. sapidus BTB domain protein (CasBTBDP) initially isolated from Y-organ cDNA, contains only Broad-Complex, Tramtrack, and Bric a brac (BTB) domains. The levels of CasBTBDP are kept constant throughout embryogenesis. The expression profiles of CasMIH and CasCHH are similar to the titers of ecdysteroids. However, the timing of their appearance is followed by increases in CasEcRs and CasRXRs, implying that the expressions of these neuropeptides may be influenced by ecdysteroids. Moreover, the ecdysteroid profile during embryogenesis may track directly with the timing of organogenesis of Y-organs and their activity. Our work reports, for first time, the observed expression and changes of ecdysteroid-responsive factors, along with CasCHH and CasMIH, during embryogenesis in the crustacean C. sapidus. Copyright © 2014 Elsevier Inc. All rights reserved.

The response of zooplankton communities to the 2016 extreme hydrological cycle in floodplain lakes connected to the Yangtze River in China.

PubMed

Zhang, Kun; Xu, Mei; Wu, Qili; Lin, Zhi; Jiang, Fangyuan; Chen, Huan; Zhou, Zhongze

2018-06-04

The Huayanghe Lakes play an important role in the Yangtze floodplain in China and had extremely high water levels during the summer of 2016. Monitoring data was collected in an effort to understand the impact of this change on the crustacean zooplankton composition and abundance and the biomass variation in the Huayanghe Lakes between a regular hydrological cycle (RHC) and an extreme hydrological cycle (EHC). The crustacean zooplankton community composition, abundance, and biomass in the floodplain lakes were markedly affected by the water-level disturbance. The number of species was lower in the RHC, but the mean density and biomass decreased from 93.84 ± 13.29 ind./L and 6.11 ± 0.89 mg/L, respectively, in the RHC to 66.62 ± 10.88 ind./L and 1.22 ± 0.26 mg/L, respectively, in the EHC. Pearson correlations and redundancy analyses revealed the environmental factors with the most significant impact on the crustacean zooplankton community differed between the RHC and EHC cycles. Little previous information exists on the zooplankton in these lakes, and the present study provides data on the zooplankton composition, abundance, and biomass, both at baseline and in response to hydrological changes.

Genome size estimates for crustaceans using Feulgen image analysis densitometry of ethanol-preserved tissues.

PubMed

Jeffery, Nicholas W; Gregory, T Ryan

2014-10-01

Crustaceans are enormously diverse both phylogenetically and ecologically, but they remain substantially underrepresented in the existing genome size database. An expansion of this dataset could be facilitated if it were possible to obtain genome size estimates from ethanol-preserved specimens. In this study, two tests were performed in order to assess the reliability of genome size data generated using preserved material. First, the results of estimates based on flash-frozen versus ethanol-preserved material were compared across 37 species of crustaceans that differ widely in genome size. Second, a comparison was made of specimens from a single species that had been stored in ethanol for 1-14 years. In both cases, the use of gill tissue in Feulgen image analysis densitometry proved to be a very viable approach. This finding is of direct relevance to both new studies of field-collected crustaceans as well as potential studies based on existing collections. © 2014 International Society for Advancement of Cytometry.

Sensomics-Assisted Elucidation of the Tastant Code of Cooked Crustaceans and Taste Reconstruction Experiments.

PubMed

Meyer, Stefanie; Dunkel, Andreas; Hofmann, Thomas

2016-02-10

Sensory-guided fractionation by means of ultrafiltration and cation-exchange chromatography, followed by MS/MS quantitation, and taste re-engineering experiments revealed the key taste molecules coining the characteristic taste profile of the cooked meat of king prawns. Furthermore, quantitative analysis demonstrated that the taste differences between crustaceans are due to quantitative differences in the combinatorial code of tastants, rather than to qualitative differences in the tastant composition. Besides the amino acids glycine, L-proline, and L-alanine, the characteristic seafood-like sweet profile was found to be due to the sweet modulatory action of quaternary ammonium compounds, among which betaine, homarine, stachydrin, and trimethylamine-N-oxide were found as the key contributors on the basis of dose-activity considerations. Knowledge of this combinatorial tastant code provides the foundation for the development of more sophisticated crustacean flavors that are lacking any heavy metal ions and allergenic proteins present when using crustacean extracts for food flavoring.

Looking back on a decade of barcoding crustaceans

PubMed Central

Raupach, Michael J.; Radulovici, Adriana E.

2015-01-01

Abstract Species identification represents a pivotal component for large-scale biodiversity studies and conservation planning but represents a challenge for many taxa when using morphological traits only. Consequently, alternative identification methods based on molecular markers have been proposed. In this context, DNA barcoding has become a popular and accepted method for the identification of unknown animals across all life stages by comparison to a reference library. In this review we examine the progress of barcoding studies for the Crustacea using the Web of Science data base from 2003 to 2014. All references were classified in terms of taxonomy covered, subject area (identification/library, genetic variability, species descriptions, phylogenetics, methods, pseudogenes/numts), habitat, geographical area, authors, journals, citations, and the use of the Barcode of Life Data Systems (BOLD). Our analysis revealed a total number of 164 barcoding studies for crustaceans with a preference for malacostracan crustaceans, in particular Decapoda, and for building reference libraries in order to identify organisms. So far, BOLD did not establish itself as a popular informatics platform among carcinologists although it offers many advantages for standardized data storage, analyses and publication. PMID:26798245

Dissociation of Circadian and Circatidal Timekeeping in the Marine Crustacean Eurydice pulchra

PubMed Central

Zhang, Lin; Hastings, Michael H.; Green, Edward W.; Tauber, Eran; Sladek, Martin; Webster, Simon G.; Kyriacou, Charalambos P.; Wilcockson, David C.

2013-01-01

Summary Background Tidal (12.4 hr) cycles of behavior and physiology adapt intertidal organisms to temporally complex coastal environments, yet their underlying mechanism is unknown. However, the very existence of an independent “circatidal” clock has been disputed, and it has been argued that tidal rhythms arise as a submultiple of a circadian clock, operating in dual oscillators whose outputs are held in antiphase i.e., ∼12.4 hr apart. Results We demonstrate that the intertidal crustacean Eurydice pulchra (Leach) exhibits robust tidal cycles of swimming in parallel to circadian (24 hr) rhythms in behavioral, physiological and molecular phenotypes. Importantly, ∼12.4 hr cycles of swimming are sustained in constant conditions, they can be entrained by suitable stimuli, and they are temperature compensated, thereby meeting the three criteria that define a biological clock. Unexpectedly, tidal rhythms (like circadian rhythms) are sensitive to pharmacological inhibition of Casein kinase 1, suggesting the possibility of shared clock substrates. However, cloning the canonical circadian genes of E. pulchra to provide molecular markers of circadian timing and also reagents to disrupt it by RNAi revealed that environmental and molecular manipulations that confound circadian timing do not affect tidal timing. Thus, competent circadian timing is neither an inevitable nor necessary element of tidal timekeeping. Conclusions We demonstrate that tidal rhythms are driven by a dedicated circatidal pacemaker that is distinct from the circadian system of E. pulchra, thereby resolving a long-standing debate regarding the nature of the circatidal mechanism. PMID:24076244

Zooplankton and the Ocean Carbon Cycle.

PubMed

Steinberg, Deborah K; Landry, Michael R

2017-01-03

Marine zooplankton comprise a phylogenetically and functionally diverse assemblage of protistan and metazoan consumers that occupy multiple trophic levels in pelagic food webs. Within this complex network, carbon flows via alternative zooplankton pathways drive temporal and spatial variability in production-grazing coupling, nutrient cycling, export, and transfer efficiency to higher trophic levels. We explore current knowledge of the processing of zooplankton food ingestion by absorption, egestion, respiration, excretion, and growth (production) processes. On a global scale, carbon fluxes are reasonably constrained by the grazing impact of microzooplankton and the respiratory requirements of mesozooplankton but are sensitive to uncertainties in trophic structure. The relative importance, combined magnitude, and efficiency of export mechanisms (mucous feeding webs, fecal pellets, molts, carcasses, and vertical migrations) likewise reflect regional variability in community structure. Climate change is expected to broadly alter carbon cycling by zooplankton and to have direct impacts on key species.

Freshwater decapod crustaceans (Palaemonidae, Cambaridae) of the Savannah River Plant, South Carolina

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

Hobbs, H.H. III; Thorp, J.H.; Anderson, G.E.

Decapod crustaceans (specifically crayfishes and freshwater shrimps) are quite numerous in the drainages of the southeastern United States and occupy an extremely important niche in aquatic systems. As predators they act as disturbance components on benthic freshwater communities and may serve an integral position in the early stages of detrital decomposition. They constitute an important prey item in the diets of a wide variety of terrestrial and aquatic vertebrate predators, including game fishes, such as Micropterus salmoides (La Crepede) and other centrarchids. Researchers at the Savannah River Plant (SRP) employ these crustaceans in studies of the effects of thermal andmore » heavy metal pollution on survival and behavior, as well as in investigations of the fates of heavy metals and radioactive pollution in freshwater environments. A common problem to these studies is the uncertainty of species determinations, and it is our intent to present an illustrated dichotomous key to the decapod crustaceans found in the aquatic habitats of the SRP. In addition, each species is treated separately with reference to specific taxonomic characters, ecology, life history, color patterns, etc. A brief discussion of collecting techniques, preservation and preparation and equipment needed for identification also is presented.« less

Do Decapod Crustaceans Have Nociceptors for Extreme pH?

PubMed Central

Puri, Sakshi; Faulkes, Zen

2010-01-01

Background Nociception is the physiological detection of noxious stimuli. Because of its obvious importance, nociception is expected to be widespread across animal taxa and to trigger robust behaviours reliably. Nociception in invertebrates, such as crustaceans, is poorly studied. Methodology/Principal Findings Three decapod crustacean species were tested for nociceptive behaviour: Louisiana red swamp crayfish (Procambarus clarkii), white shrimp (Litopenaeus setiferus), and grass shrimp (Palaemonetes sp.). Applying sodium hydroxide, hydrochloric acid, or benzocaine to the antennae caused no change in behaviour in the three species compared to controls. Animals did not groom the stimulated antenna, and there was no difference in movement of treated individuals and controls. Extracellular recordings of antennal nerves in P. clarkii revealed continual spontaneous activity, but no neurons that were reliably excited by the application of concentrated sodium hydroxide or hydrochloric acid. Conclusions/Significance Previously reported responses to extreme pH are either not consistently evoked across species or were mischaracterized as nociception. There was no behavioural or physiological evidence that the antennae contained specialized nociceptors that responded to pH. PMID:20422026

Conjugation in Hyalophysa chattoni Bradbury (Apostomatida): An adaptation to a symbiotic life cycle.

PubMed

Bradbury, Phyllis Clarke; Hash, Stephen M; Rogers, Faye Kucera; Neptun, Steven H; Zhang, Limin

2013-11-01

Hyalophysa chattoni, borne as an encysted phoront on a crustacean's exoskeleton, metamorphoses to the trophont during the host's premolt. After the molt within 15min to 2h conjugants with food vacuoles appear in the exuvium, swimming along with the trophonts. Starvation in other ciliates usually precedes conjugation, but food vacuoles in conjugants do not preclude starvation. Only after ingestion and dehydration of vacuoles ceases, does digestion of exuvial fluid begin. Conjugants resorb their feeding apparatus as they fuse. A single imperforate membrane from each partner forms the junction membrane. In a reproductive cyst conjugants divide synchronously, but now the junction membrane is interrupted by pores and channels. After the last division the daughters undergo meiosis--two meiotic divisions and one mitotic division yielding two prokarya as they simultaneously differentiate into tomites. After fertilization, pairs separate and the synkaryon divides once into a macronuclear anlage and a micronucleus. Exconjugants leave the cyst and seek a host. The parental macronucleus remains active until the phoront stage when the anlage develops. Owing to random association of micronuclei during meiosis, Hyalophysa's exconjugants are more genetically diverse than exconjugants from conventional patterns of conjugation. Copyright © 2013 Elsevier GmbH. All rights reserved.

Recrudescence Mechanisms and Gene Expression Profile of the Reproductive Tracts from Chickens during the Molting Period

PubMed Central

Ahn, Suzie E.; Lim, Chul-Hong; Lee, Jin-Young; Bae, Seung-Min; Kim, Jinyoung; Bazer, Fuller W.; Song, Gwonhwa

2013-01-01

The reproductive system of chickens undergoes dynamic morphological and functional tissue remodeling during the molting period. The present study identified global gene expression profiles following oviductal tissue regression and regeneration in laying hens in which molting was induced by feeding high levels of zinc in the diet. During the molting and recrudescence processes, progressive morphological and physiological changes included regression and re-growth of reproductive organs and fluctuations in concentrations of testosterone, progesterone, estradiol and corticosterone in blood. The cDNA microarray analysis of oviductal tissues revealed the biological significance of gene expression-based modulation in oviductal tissue during its remodeling. Based on the gene expression profiles, expression patterns of selected genes such as, TF, ANGPTL3, p20K, PTN, AvBD11 and SERPINB3 exhibited similar patterns in expression with gradual decreases during regression of the oviduct and sequential increases during resurrection of the functional oviduct. Also, miR-1689* inhibited expression of Sp1, while miR-17-3p, miR-22* and miR-1764 inhibited expression of STAT1. Similarly, chicken miR-1562 and miR-138 reduced the expression of ANGPTL3 and p20K, respectively. These results suggest that these differentially regulated genes are closely correlated with the molecular mechanism(s) for development and tissue remodeling of the avian female reproductive tract, and that miRNA-mediated regulation of key genes likely contributes to remodeling of the avian reproductive tract by controlling expression of those genes post-transcriptionally. The discovered global gene profiles provide new molecular candidates responsible for regulating morphological and functional recrudescence of the avian reproductive tract, and provide novel insights into understanding the remodeling process at the genomic and epigenomic levels. PMID:24098561

Searching for consensus in molt terminology 11 years after Howell et al.'s "first basic problem"

Treesearch

Jared D. Wolfe; Erik I. Johnson; Ryan S. Terrill

2014-01-01

Howell et al. (2003) published an innovative augmentation to terminology proposed by Humphrey and Parkes (1959) that classified bird molt on the basis of perceived evolutionary relationships. Despite apparent universal applicability, Howell et al.’s (2003) proposed terminological changes were met with criticism that cited a failure to verify the evolutionary...

Stable hydrogen isotope analysis of bat hair as evidence for seasonal molt and long-distance migration

USGS Publications Warehouse

Cryan, P.M.; Bogan, M.A.; Rye, R.O.; Landis, G.P.; Kester, C.L.

2004-01-01

Although hoary bats (Lasiurus cinereus) are presumed to be migratory and capable of long-distance dispersal, traditional marking techniques have failed to provide direct evidence of migratory movements by individuals. We measured the stable hydrogen isotope ratios of bat hair (δDh) and determined how these values relate to stable hydrogen isotope ratios of precipitation (δDp). Our results indicate that the major assumptions of stable isotope migration studies hold true for hoary bats and that the methodology provides a viable means of determining their migratory movements. We present evidence that a single annual molt occurs in L. cinereus prior to migration and that there is a strong relationship between δDh and δDp during the molt period. This presumably reflects the incorporation of local δDp into newly grown hair. Furthermore, we present evidence that individual hoary bats are capable of traveling distances in excess of 2,000 km and that hair is grown at a wide range of latitudes and elevations. Stable hydrogen isotope analysis offers a promising new tool for the study of bat migration.

Blood selenium concentrations in female Pacific black brant molting in Arctic Alaska: Relationships with age and habitat salinity.

PubMed

Franson, J Christian; Flint, Paul L; Schmutz, Joel A

2016-10-15

Blood samples collected from 81 female Pacific black brant (Branta bernicla nigricans) molting near Teshekpuk Lake, Alaska, were analyzed for selenium concentration. The concentration of selenium in blood of after second year (hatched two or more years ago) females (0.84μg/g wet weight) was significantly greater than the concentration in second year (hatched the previous year) females (0.61μg/g wet weight). The concentrations of selenium we found in blood of black brant were 1.5 to 2 times greater than baseline values typical of freshwater birds, but considerably lower than reported in other marine waterfowl sampled in Alaska. This finding may be attributable in part to the nearly exclusive herbivorous diet of black brant. No relationship was noted between blood selenium concentration and molting habitat salinity. We are unaware of any previous reports of blood selenium concentrations in black brant. Published by Elsevier Ltd.

Blood selenium concentrations in female Pacific black brant molting in Arctic Alaska: Relationships with age and habitat salinity

USGS Publications Warehouse

Franson, J. Christian; Flint, Paul L.; Schmutz, Joel A.

2016-01-01

Blood samples collected from 81 female Pacific black brant (Branta bernicla nigricans) molting near Teshekpuk Lake, Alaska, were analyzed for selenium concentration. The concentration of selenium in blood of after second year (hatched two or more years ago) females (0.84 μg/g wet weight) was significantly greater than the concentration in second year (hatched the previous year) females (0.61 μg/g wet weight). The concentrations of selenium we found in blood of black brant were 1.5 to 2 times greater than baseline values typical of freshwater birds, but considerably lower than reported in other marine waterfowl sampled in Alaska. This finding may be attributable in part to the nearly exclusive herbivorous diet of black brant. No relationship was noted between blood selenium concentration and molting habitat salinity. We are unaware of any previous reports of blood selenium concentrations in black brant.

Roles of small RNAs in the immune defense mechanisms of crustaceans.

PubMed

He, Yaodong; Ju, Chenyu; Zhang, Xiaobo

2015-12-01

Small RNAs, 21-24 nucleotides in length, are non-coding RNAs found in most multicellular organisms, as well as in some viruses. There are three main types of small RNAs including microRNA (miRNA), small-interfering RNA (siRNA), and piwi-interacting RNA (piRNA). Small RNAs play key roles in the genetic regulation of eukaryotes; at least 50% of all eukaryote genes are the targets of small RNAs. In recent years, studies have shown that some unique small RNAs are involved in the immune response of crustaceans, leading to lower or higher immune responses to infections and diseases. SiRNAs could be used as therapy for virus infection. In this review, we provide an overview of the diverse roles of small RNAs in the immune defense mechanisms of crustaceans. Copyright © 2015 Elsevier Ltd. All rights reserved.

Efficacy of protein, symbiotic and probiotic supplementation on production performance and egg quality characteristics in molted layers.

PubMed

Anwar, Haseeb; Rahman, Zia Ur

2016-10-01

Two hundred white leg horn layers at 70 weeks of age were induced to molt with high dietary zinc (3 g/kg of feed); thereafter, birds were equally and randomly divided (n = 50 each) into four groups keeping G1 as control (CP 16 % diet, no other supplement), G2 (CP 18 % diet), G3 (CP 16 % diet + symbiotic; Perfectin® at 85 mg/L in drinking water daily), and G4 (CP 16 % diet + probiotic; Protexin® at 85 mg/L in drinking water daily). The egg production record was maintained throughout the experiment period, and egg quality parameters were performed at 5 %, peak, and end of post molt production stage. The overall egg production was highest in G2 (74.51 %) followed by G3 (64.95 %) and G4 (65.03 %) and lowest in G1 (58.51 %). The overall egg weight, length, diameter, weight and diameter of albumin and yolk, egg shell thickness as well as egg shell breaking strength increased (P ≤ 0.01) in G2 and G3 as compared to G1. The albumin height, yolk height, yolk index, and haugh unit score decreased (P ≤ 0.01) in G2 and G3 as compared to G1. FCR/12 eggs improved in all the supplemented groups as compared to control (G1). The bacterial contamination of eggs was seen in G1. Conclusively, it was observed in the current experiment that the supplementation with protein, probiotic, and symbiotic did improve the production quality and potential in molted layers.

REPRODUCTIVE AND DEVELOPMENTAL SCREENING PROTOCOLS FOR ENDOCRINE DISRUPTORS USING ESTUARINE CRUSTACEANS

EPA Science Inventory

The objective of this research is to develop in vivo screening protocols for endocrine disruption in marine crustaceans, invertebrates of ecological and economic importance. A series of comparative developmental and reproductive studies were performed on several species of estuar...

Inorganic Contaminants, Nutrient Reserves and Molt Intensity in Autumn Migrant Red-Necked Grebes (Podiceps grisegena) at Georgian Bay.

PubMed

Holman, Katie L; Schummer, Michael L; Petrie, Scott A; Chen, Yu-Wei; Belzile, Nelson

2015-11-01

Red-necked grebes (Podiceps grisegena) are piscivorous waterbirds that breed on freshwater lakes in northwestern Canada and stop-over at the Great Lakes during autumn migration to molt feathers and replenish lipid and protein reserves. The objectives of this study were to (1) describe concentrations of, and correlations among, inorganic contaminants in a sample of autumn migrant red-necked grebes from the Great Lakes, (2) compare concentrations of inorganic contaminants to those in autumn migrant common loons from Schummer et al. (Arch Environ Contam Toxicol 62:704, 2011a), (3) evaluate if the inorganic elements are negatively associated with lipid and protein reserves, and (4) determine if nutrient reserves and molt intensity were correlated. None of the 14 contaminants analyzed were above threshold levels known to cause acute health problems in piscivorous birds. Body masses of plucked birds were within the normal reported range. Lipid reserves varied positively with hepatic concentrations of arsenic, copper, iron, nickel, lead, and selenium and negatively with mercury and magnesium. Protein reserves variety negatively with hepatic concentrations of arsenic, calcium, nickel, lead, and zinc and positively with aluminum, cadmium, and iron. A negative correlation was observed between chest molt and lipid reserves but not between nutrient reserves and other feather tracts. The relationships between lipid reserves and both mercury and selenium were consistent with current research on other piscivorous waterbirds at the Great Lakes and justify continued work to determine interactions of these contaminants in waterbirds that breed, stage, and winter in the region.

Ontogeny and function of the fifth limb in Cypridocopain ostracods.

PubMed

Kaji, Tomonari

2010-08-01

The exoskeleton of arthropods undergoes reformation at every molting. Accordingly, external morphology can metamorphose through molting. In some crustaceans, the function of appendages is modified through ontogeny. These morphological modifications require accordant modification of the correlation between different body parts because the morphological function depends on the combined correlation between different parts. In the case of crustacean morphology, exoskeleton and muscles are correlated to each other. The functional morphology of the fifth limb of cypridoid ostracods transforms from "walking leg + mouthparts (+ possibly respiratory parts)" to "mouthparts + respiratory parts + grasping hook (in males only)" through ontogeny. In this study, the three-dimensional structures of the exoskeleton and muscular systems were observed by confocal laser-scanning microscopy in some species of suborder Cypridocopina. The muscular system is reportedly not changed by the ontogeny of appendages in females, but it does change in males. Furthermore, regional cell proliferation, which was detected previously, represented the causal factor of exoskeletal modification. I therefore conclude that the enlarged endite in the female fifth limb is produced by exoskeletal modification based on regional cell proliferation, rather than by a change in the muscular system. In contrast, modification in the male requires a change in the muscular system in addition to exoskeletal modification.

The insulin-like androgenic gland hormone in crustaceans: From a single gene silencing to a wide array of sexual manipulation-based biotechnologies.

PubMed

Ventura, Tomer; Sagi, Amir

2012-01-01

Due to the over-harvesting and deterioration of wild populations, the ever-growing crustacean market is increasingly reliant on aquaculture, driving the need for better management techniques. Since most cultured crustacean species exhibit sexually dimorphic growth patterns, the culture of monosex populations (either all-male or all-female) is a preferred approach for gaining higher yields, with the ecological benefit of reducing the risk of invasion by the cultured species. Sexual manipulations may also render sustainable solutions to the environmental problems caused by the presence of invasive crustacean species with detrimental impacts ranging from aggressive competition with native species for food and shelter, to affecting aquaculture facilities and harvests and causing structural damage to river banks. Recent discoveries of androgenic gland (AG)-specific insulin-like peptides (IAGs) in crustaceans and the ability to manipulate them and their encoding transcripts (IAGs) have raised the possibility of sexually manipulating crustacean populations. Sexual manipulation is already a part of sustainable solutions in fish aquaculture and in the bio-control of insect pest species, and attempts are also being made to implement it with crustaceans. As recently exemplified in a commercially important prawn species, IAG silencing, a temporal, non-genetically modifying and non-transmissible intervention, has enabled the production of non-breeding all-male monosex populations that are the progeny of sexually reversed males ('neo-females'). IAG manipulations-based biotechnologies therefore have the potential to radically transform the entire industry. We review here how this proof of concept could be broadened to meet both aquacultural and environmental needs. We include the major cultured decapod crustacean groups and suggest a sustainable solution for the management of invasive and pest crustacean species. We also review the key considerations for devising a

Spatial and temporal variation in ephemeral pool crustacean communities

Treesearch

Janette Holtz; Marie A. Simovich; Thomas Philippi

2005-01-01

Vernal pool habitat losses in San Diego County, California, are estimated at 95 percent and will increase as development continues. The majority of San Diego’s remaining pools are located at the Marine Corps Air Station, Miramar. Crustacean communities in eight vernal pools in San Diego County were sampled over 3 years that differed in rainfall amount and pattern. In...

Sampling Daphnia's expressed genes: preservation, expansion and invention of crustacean genes with reference to insect genomes

PubMed Central

Colbourne, John K; Eads, Brian D; Shaw, Joseph; Bohuski, Elizabeth; Bauer, Darren J; Andrews, Justen

2007-01-01

Background Functional and comparative studies of insect genomes have shed light on the complement of genes, which in part, account for shared morphologies, developmental programs and life-histories. Contrasting the gene inventories of insects to those of the nematodes provides insight into the genomic changes responsible for their diversification. However, nematodes have weak relationships to insects, as each belongs to separate animal phyla. A better outgroup to distinguish lineage specific novelties would include other members of Arthropoda. For example, crustaceans are close allies to the insects (together forming Pancrustacea) and their fascinating aquatic lifestyle provides an important comparison for understanding the genetic basis of adaptations to life on land versus life in water. Results This study reports on the first characterization of cDNA libraries and sequences for the model crustacean Daphnia pulex. We analyzed 1,546 ESTs of which 1,414 represent approximately 787 nuclear genes, by measuring their sequence similarities with insect and nematode proteomes. The provisional annotation of genes is supported by expression data from microarray studies described in companion papers. Loci expected to be shared between crustaceans and insects because of their mutual biological features are identified, including genes for reproduction, regulation and cellular processes. We identify genes that are likely derived within Pancrustacea or lost within the nematodes. Moreover, lineage specific gene family expansions are identified, which suggest certain biological demands associated with their ecological setting. In particular, up to seven distinct ferritin loci are found in Daphnia compared to three in most insects. Finally, a substantial fraction of the sampled gene transcripts shares no sequence similarity with those from other arthropods. Genes functioning during development and reproduction are comparatively well conserved between crustaceans and insects. By

Impacts of a North Pacific Predator on Nearshore Seawater Mercury Cycling via Top-Down Contamination

NASA Astrophysics Data System (ADS)

Cossaboon, J. M.; Ganguli, P. M.; Flegal, A. R., Jr.

2015-12-01

Marine mammals are common sentinel species for studying marine pollution, however their potential role as vectors of contaminants to local ecosystems has rarely been addressed. Organic methylmercury, or MeHg, is a potent neurotoxin that biomagnifies approximately one to ten million-fold in aquatic carnivores such as the Northern elephant seal (Mirounga angustirostris), whose excreta and molted pelage, in turn, constitute a source of environmental MeHg contamination at the base of marine food chains. This recycling of MeHg was evidenced by comparing total mercury (HgT) and MeHg concentrations in seawater at the Año Nuevo State Reserve pinniped rookery to those of neighboring coastal sites in Central California. The observed 17-fold enrichment of MeHg in seawater at Año Nuevo during the M. angustirostris molting season (0.28—9.5 pM) was remarkable, and exceeded the range of surface water MeHg concentrations observed in the highly urbanized San Francisco Bay estuary (<0.05—2.3 pM). The importance of MeHg inputs to Año Nuevo waters from Northern elephant seals was confirmed by the HgT concentrations in molted pelage samples (average = 3.6 μg g-1 dry wt.), which presumably contained >80% MeHg. This equates to an annual per-capita emission factor of 0.05 g MeHg per adult elephant seal. Based on this estimate, we calculate that approximately 0.2 kg of organic Hg entered the nearshore environment of Año Nuevo during that molting season. This elevated methylmercury (MeHg) in seawater adjacent to the rookery may become bioavailable to lower trophic levels, demonstrating that marine mammal colonization can substantially influence nearshore mercury cycling and potentially threaten ecosystem health.

Calcium phosphate mineralization is widely applied in crustacean mandibles.

PubMed

Bentov, Shmuel; Aflalo, Eliahu D; Tynyakov, Jenny; Glazer, Lilah; Sagi, Amir

2016-02-24

Crustaceans, like most mineralized invertebrates, adopted calcium carbonate mineralization for bulk skeleton reinforcement. Here, we show that a major part of the crustacean class Malacostraca (which includes lobsters, crayfishes, prawns and shrimps) shifted toward the formation of calcium phosphate as the main mineral at specified locations of the mandibular teeth. In these structures, calcium phosphate is not merely co-precipitated with the bulk calcium carbonate but rather creates specialized structures in which a layer of calcium phosphate, frequently in the form of crystalline fluorapatite, is mounted over a calcareous "jaw". From a functional perspective, the co-existence of carbonate and phosphate mineralization demonstrates a biomineralization system that provides a versatile route to control the physico-chemical properties of skeletal elements. This system enables the deposition of amorphous calcium carbonate, amorphous calcium phosphate, calcite and apatite at various skeletal locations, as well as combinations of these minerals, to form graded composites materials. This study demonstrates the widespread occurrence of the dual mineralization strategy in the Malacostraca, suggesting that in terms of evolution, this feature of phosphatic teeth did not evolve independently in the different groups but rather represents an early common trait.

Calcium phosphate mineralization is widely applied in crustacean mandibles

PubMed Central

Bentov, Shmuel; Aflalo, Eliahu D.; Tynyakov, Jenny; Glazer, Lilah; Sagi, Amir

2016-01-01

Crustaceans, like most mineralized invertebrates, adopted calcium carbonate mineralization for bulk skeleton reinforcement. Here, we show that a major part of the crustacean class Malacostraca (which includes lobsters, crayfishes, prawns and shrimps) shifted toward the formation of calcium phosphate as the main mineral at specified locations of the mandibular teeth. In these structures, calcium phosphate is not merely co-precipitated with the bulk calcium carbonate but rather creates specialized structures in which a layer of calcium phosphate, frequently in the form of crystalline fluorapatite, is mounted over a calcareous “jaw”. From a functional perspective, the co-existence of carbonate and phosphate mineralization demonstrates a biomineralization system that provides a versatile route to control the physico-chemical properties of skeletal elements. This system enables the deposition of amorphous calcium carbonate, amorphous calcium phosphate, calcite and apatite at various skeletal locations, as well as combinations of these minerals, to form graded composites materials. This study demonstrates the widespread occurrence of the dual mineralization strategy in the Malacostraca, suggesting that in terms of evolution, this feature of phosphatic teeth did not evolve independently in the different groups but rather represents an early common trait. PMID:26906263

A taxonomic review of viruses infecting crustaceans with an emphasis on wild hosts.

PubMed

Bateman, K S; Stentiford, G D

2017-07-01

Numerous infections by viral pathogens have been described from wild and cultured crustacean hosts, yet relatively few of these pathogens have been formally characterised and classified. To date viruses have generally been tentatively assigned to families based upon morphological and developmental characteristics and their location of infection within the host cell. Often nucleotide sequence information is unavailable. Some of these viral infections have caused well-documented devastating consequences on the global crustacean farming industry whilst their effects on wild populations remain largely unstudied. This paper provides an up to date review of all known viruses described infecting crustacean hosts. Full characterisation and harmonisation of these descriptions utilising specifications proposed by the International Committee on Taxonomy of Viruses (ICTV) is required to synonymise numerous examples of differential naming or abbreviation of naming, of the same virus in some cases. Development and application of techniques such as viral purification and high throughput sequencing of viral genomes will assist with these full descriptions and, provide appropriate diagnostic targets for surveillance of known and novel relatives. This review also highlights the importance of comparative study with viruses infecting insects and other arthropods to assist this process. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Identification and characterisation of the ecdysone biosynthetic genes neverland, disembodied and shade in the salmon louse Lepeophtheirus salmonis (Copepoda, Caligidae)

PubMed Central

Kongshaug, Heidi; Horsberg, Tor Einar; Male, Rune; Nilsen, Frank; Dalvin, Sussie

2018-01-01

The salmon louse is a marine ectoparasitic copepod on salmonid fishes. Its lifecycle consists of eight developmental stages, each separated by a molt. In crustaceans and insects, molting and reproduction is controlled by circulating steroid hormones such as 20-hydroxyecdysone. Steroid hormones are synthesized from cholesterol through catalytic reactions involving a 7,8-dehydrogenase Neverland and several cytochrome P450 genes collectively called the Halloween genes. In this study, we have isolated and identified orthologs of neverland, disembodied and shade in the salmon louse (Lepeophtheirus salmonis) genome. Tissue-specific expression analysis show that the genes are expressed in intestine and reproductive tissue. In addition, levels of the steroid hormones ecdysone, 20-hydroxyecdysone and ponasterone A were measured during the reproductive stage of adult females and in early life stages. PMID:29401467

Genes involved in thoracic exoskeleton formation during the pupal-to-adult molt in a social insect model, Apis mellifera.

PubMed

Soares, Michelle Prioli Miranda; Barchuk, Angel Roberto; Simões, Ana Carolina Quirino; Dos Santos Cristino, Alexandre; de Paula Freitas, Flávia Cristina; Canhos, Luísa Lange; Bitondi, Márcia Maria Gentile

2013-08-28

The insect exoskeleton provides shape, waterproofing, and locomotion via attached somatic muscles. The exoskeleton is renewed during molting, a process regulated by ecdysteroid hormones. The holometabolous pupa transforms into an adult during the imaginal molt, when the epidermis synthe3sizes the definitive exoskeleton that then differentiates progressively. An important issue in insect development concerns how the exoskeletal regions are constructed to provide their morphological, physiological and mechanical functions. We used whole-genome oligonucleotide microarrays to screen for genes involved in exoskeletal formation in the honeybee thoracic dorsum. Our analysis included three sampling times during the pupal-to-adult molt, i.e., before, during and after the ecdysteroid-induced apolysis that triggers synthesis of the adult exoskeleton. Gene ontology annotation based on orthologous relationships with Drosophila melanogaster genes placed the honeybee differentially expressed genes (DEGs) into distinct categories of Biological Process and Molecular Function, depending on developmental time, revealing the functional elements required for adult exoskeleton formation. Of the 1,253 unique DEGs, 547 were upregulated in the thoracic dorsum after apolysis, suggesting induction by the ecdysteroid pulse. The upregulated gene set included 20 of the 47 cuticular protein (CP) genes that were previously identified in the honeybee genome, and three novel putative CP genes that do not belong to a known CP family. In situ hybridization showed that two of the novel genes were abundantly expressed in the epidermis during adult exoskeleton formation, strongly implicating them as genuine CP genes. Conserved sequence motifs identified the CP genes as members of the CPR, Tweedle, Apidermin, CPF, CPLCP1 and Analogous-to-Peritrophins families. Furthermore, 28 of the 36 muscle-related DEGs were upregulated during the de novo formation of striated fibers attached to the exoskeleton. A

[Faunal characteristics and distribution pattern of crustaceans in the vicinity of Pearl River estuary].

PubMed

Huang, Zi-Rong; Sun, Dian-Rong; Chen, Zuo-Zhi; Zhang, Han-Hua; Wang, Xue-Hui; Wang, Yue-Zhong; Fang, Hong-Da; Dong, Yan-Hong

2009-10-01

Based on the data of bottom trawl surveys in the vicinity of Pearl River estuary in August (summer), October (autumn), December (winter) 2006, and April (spring) 2007, the faunal characteristics and distribution pattern of crustaceans were analyzed. A total of 54 species belonging to 25 genera, 17 families, and 2 orders were collected, including 22 species of shrimps, 22 species of crabs, and 10 species of squills. Most of the crustaceans were tropical-subtropical warm-water species, a few of them were eurythermal species, and no warm-water and cold-water species occurred. Euryhaline species were most abundant, followed by halophile species, and the low-salinity species were the least. Most of the crustacean species belonged to the fauna of Indian Ocean-western Pacific Ocean. The faunal assemblages were closer to those of the East China Sea, Philippine Sea, Indonesia Sea, and the Japan Sea, and estranger with those of the Yellow Sea, Bohai Sea, and Korea Sea. The dominant species were Metapenaeus joyner, Oratosquilla oratoria, Charybdis miles, Portunus sanguinolentus, Harpiosquilla harpax, Charybdis feriatus, Charybdis japonica, Oratosquilla nepa, Solenocera crassicornis, Portunus trituberculatus, and Calappa philargius. The crustaceans had the largest species number (33) in autumn and the least one (26) in spring, and the highest stock density at the water depth of < 40 m, especially at 10-20 m. The average stock density of the crustaceans was estimated to be 99.60 kg x km(-2), with the highest (198.93 kg x km(-2)) in summer and the lowest (42.35 kg x km(-2)) in spring. Of the 3 species groups, crabs had the highest stock density (41.81 kg x km(-2)), followed by shrimps (38.91 kg x km(-2)), and squills (18.88 kg x km(-2)). The stock densities of the 3 species groups showed an obvious seasonal variation. Shrimps had the highest stock density (120.32 kg x km(-2)) in summer and the lowest density (0.67 kg x km(-2)) in spring, while crabs and squills had the highest

Ionotropic crustacean olfactory receptors.

PubMed

Corey, Elizabeth A; Bobkov, Yuriy; Ukhanov, Kirill; Ache, Barry W

2013-01-01

The nature of the olfactory receptor in crustaceans, a major group of arthropods, has remained elusive. We report that spiny lobsters, Panulirus argus, express ionotropic receptors (IRs), the insect chemosensory variants of ionotropic glutamate receptors. Unlike insects IRs, which are expressed in a specific subset of olfactory cells, two lobster IR subunits are expressed in most, if not all, lobster olfactory receptor neurons (ORNs), as confirmed by antibody labeling and in situ hybridization. Ligand-specific ORN responses visualized by calcium imaging are consistent with a restricted expression pattern found for other potential subunits, suggesting that cell-specific expression of uncommon IR subunits determines the ligand sensitivity of individual cells. IRs are the only type of olfactory receptor that we have detected in spiny lobster olfactory tissue, suggesting that they likely mediate olfactory signaling. Given long-standing evidence for G protein-mediated signaling in activation of lobster ORNs, this finding raises the interesting specter that IRs act in concert with second messenger-mediated signaling.

Biological Surface Coating and Molting Inhibition as Mechanisms of TiO2 Nanoparticle Toxicity in Daphnia magna

PubMed Central

Dabrunz, André; Duester, Lars; Prasse, Carsten; Seitz, Frank; Rosenfeldt, Ricki; Schilde, Carsten; Schaumann, Gabriele E.; Schulz, Ralf

2011-01-01

The production and use of nanoparticles (NP) has steadily increased within the last decade; however, knowledge about risks of NP to human health and ecosystems is still scarce. Common knowledge concerning NP effects on freshwater organisms is largely limited to standard short-term (≤48 h) toxicity tests, which lack both NP fate characterization and an understanding of the mechanisms underlying toxicity. Employing slightly longer exposure times (72 to 96 h), we found that suspensions of nanosized (∼100 nm initial mean diameter) titanium dioxide (nTiO2) led to toxicity in Daphnia magna at nominal concentrations of 3.8 (72-h EC50) and 0.73 mg/L (96-h EC50). However, nTiO2 disappeared quickly from the ISO-medium water phase, resulting in toxicity levels as low as 0.24 mg/L (96-h EC50) based on measured concentrations. Moreover, we showed that nTiO2 (∼100 nm) is significantly more toxic than non-nanosized TiO2 (∼200 nm) prepared from the same stock suspension. Most importantly, we hypothesized a mechanistic chain of events for nTiO2 toxicity in D. magna that involves the coating of the organism surface with nTiO2 combined with a molting disruption. Neonate D. magna (≤6 h) exposed to 2 mg/L nTiO2 exhibited a “biological surface coating” that disappeared within 36 h, during which the first molting was successfully managed by 100% of the exposed organisms. Continued exposure up to 96 h led to a renewed formation of the surface coating and significantly reduced the molting rate to 10%, resulting in 90% mortality. Because coating of aquatic organisms by manmade NP might be ubiquitous in nature, this form of physical NP toxicity might result in widespread negative impacts on environmental health. PMID:21647422

Ecdysteroid and chitinase fluctuations in the western tarnished plant bug (Lygus hesperus) prior to molt indicate roles in development

USDA-ARS?s Scientific Manuscript database

Vital physiological processes that drive the insect molt represent areas of interest for the development of alternative control strategies. The western tarnished plant bug (Lygus hesperus Knight) is a pest of numerous agronomic and horticultural crops but the development of novel control approaches ...

LTR-Retrotransposons in R. exoculata and Other Crustaceans: The Outstanding Success of GalEa-Like Copia Elements

PubMed Central

Esnault, Caroline; Graça, Paula; Higuet, Dominique; Bonnivard, Eric

2013-01-01

Transposable elements are major constituents of eukaryote genomes and have a great impact on genome structure and stability. They can contribute to the genetic diversity and evolution of organisms. Knowledge of their distribution among several genomes is an essential condition to study their dynamics and to better understand their role in species evolution. LTR-retrotransposons have been reported in many diverse eukaryote species, describing a ubiquitous distribution. Given their abundance, diversity and their extended ranges in C-values, environment and life styles, crustaceans are a great taxon to investigate the genomic component of adaptation and its possible relationships with TEs. However, crustaceans have been greatly underrepresented in transposable element studies. Using both degenerate PCR and in silico approaches, we have identified 35 Copia and 46 Gypsy families in 15 and 18 crustacean species, respectively. In particular, we characterized several full-length elements from the shrimp Rimicaris exoculata that is listed as a model organism from hydrothermal vents. Phylogenic analyses show that Copia and Gypsy retrotransposons likely present two opposite dynamics within crustaceans. The Gypsy elements appear relatively frequent and diverse whereas Copia are much more homogeneous, as 29 of them belong to the single GalEa clade, and species- or lineage-dependent. Our results also support the hypothesis of the Copia retrotransposon scarcity in metazoans compared to Gypsy elements. In such a context, the GalEa-like elements present an outstanding wide distribution among eukaryotes, from fishes to red algae, and can be even highly predominant within a large taxon, such as Malacostraca. Their distribution among crustaceans suggests a dynamics that follows a “domino days spreading” branching process in which successive amplifications may interact positively. PMID:23469217

WAFs lead molting retardation of naupliar stages with down-regulated expression profiles of chitin metabolic pathway and related genes in the copepod Tigriopus japonicus.

PubMed

Hwang, Dae-Sik; Lee, Min-Chul; Kyung, Do-Hyun; Kim, Hui-Su; Han, Jeonghoon; Kim, Il-Chan; Puthumana, Jayesh; Lee, Jae-Seong

2017-03-01

Oil pollution is considered being disastrous to marine organisms and ecosystems. As molting is critical in the developmental process of arthropods in general and copepods, in particular, the impact will be adverse if the target of spilled oil is on molting. Thus, we investigated the harmful effects of water accommodated fractions (WAFs) of crude oil with an emphasis on inhibition of chitin metabolic pathways related genes and developmental retardation in the copepod Tigriopus japonicus. Also, we analysed the ontology and domain of chitin metabolic pathway genes and mRNA expression patterns of developmental stage-specific genes. Further, the developmental retardation followed by transcriptional modulations in nuclear receptor genes (NR) and chitin metabolic pathway-related genes were observed in the WAFs-exposed T. japonicus. As a result, the developmental time was found significantly (P<0.05) delayed in response to 40% WAFs in comparison with that of control. Moreover, the NR gene, HR3 and chitinases (CHT9 and CHT10) were up-regulated in N4-5 stages, while chitin synthase genes (CHS-1, CHS-2-1, and CHS-2-2) down-regulated in response to WAFs. In brief, a high concentration of WAFs repressed nuclear receptor genes but elicited activation of some of the transcription factors at low concentration of WAFs, resulting in suppression of chitin synthesis. Thus, we suggest that WAF can lead molting retardation of naupliar stages in T. japonicus through down-regulations of chitin metabolism. These findings will provide a better understanding of the mode of action of chitin biosynthesis associated with molting mechanism in WAF-exposed T. japonicus. Copyright © 2016 Elsevier Inc. All rights reserved.

Blood chemistry of wild Brazilian Coscoroba Swans during molt.

PubMed

Calabuig, Cecilia Pérez; Ferrer, Miguel; Muriel, Roberto

2010-04-01

The Coscoroba Swan (Coscoroba coscoroba) is an unusual member of the Anatidae found in South America, from the Falkland Islands and Tierra del Fuego through Chile and Argentina, Uruguay, and Paraguay as far north as Mato Grosso do Sul in Brazil. The species is not threatened globally, but some local populations have declined and the status of others is unknown. The objective of this study was to quantify the plasma chemistry of a wild population of Coscoroba Swans in southern Brazil during their molting period. We captured 12 chicks, 14 juveniles, and 31 mature birds. The following blood parameters were measured: glucose, cholesterol, triglycerides, HDL cholesterol, uric acid, creatine-kinase, aspartate amino transferase, alanine-aminotransferase, alkaline phosphatase, amylase, and pancreatic amylase. Significant differences between males and females were not observed for any of the parameters, and only the levels of alkaline phosphatase differed significantly among age groups.

Soft-sediment crustacean diversity and distribution along the Portuguese continental shelf

NASA Astrophysics Data System (ADS)

Sampaio, Leandro; Mamede, Renato; Ricardo, Fernando; Magalhães, Luísa; Rocha, Hélder; Martins, Roberto; Dauvin, Jean-Claude; Rodrigues, Ana Maria; Quintino, Victor

2016-11-01

This study analyzed the crustacean diversity, distribution and relationship with environmental factors in the western and the southern Portuguese continental shelf, between 10 and 200 m depth. A total of 10,639 specimens belonging to 242 taxa from 90 families were identified, mostly amphipods (55.8% of the total taxa). The mysid Gastrosaccus spinifer and the amphipods Socarnes erythrophthalmus and Cheirocratus sundevallii were the most abundant and the amphipods Ampelisca brevicornis, Leucothoe incisa and Autonoe spiniventris were the most frequent species. The highest abundance and diversity was found in coarser sediments with up to 306 individuals per 0.1 m2. Alpha diversity ranged from 1 to 28 sp./0.1 m2. Moreover, this study confirmed six previously doubtful first records and added an additional 19 new records to the Portuguese fauna. The results also confirmed the Portuguese coast as a transition zone of mixed Atlantic and Mediterranean faunas and exposed a noticeable North African and Macaronesian influence. A multivariate analysis based on the abundance of crustaceans revealed six affinity groups characterized by: (a) C. sundevallii, Guernea (Guernea) coalita and Sarsinebalia cristoboi on very coarse sands; (b) G. spinifer, Nototropis falcatus and Pontocrates arenarius on coarse sands; (c) Othomaera othonis, Processa modica modica and Animoceradocus semiserratus on heterogeneous medium sands; (d) A. brevicornis, Urothoe pulchella and Necalianassa truncata on fine sands; (e) Ampelisca pectenata, Bodotria scorpioides and Astacilla dilatata on heterogeneous fine sands and (f) Callianassa subterranea, Ampelisca tenuicornis and Ampelisca typica on muddy fine sands. Sediment grain-size and depth were the variables best related to the benthic crustacean spatial distribution patterns along the Portuguese continental shelf.

Reliable, responsive pacemaking and pattern generation with minimal cell numbers: the crustacean cardiac ganglion.

PubMed

Cooke, Ian M

2002-04-01

Investigations of the electrophysiology of crustacean cardiac ganglia over the last half-century are reviewed for their contributions to elucidating the cellular mechanisms and interactions by which a small (as few as nine cells) neuronal network accomplishes extremely reliable, rhythmical, patterned activation of muscular activity-in this case, beating of the neurogenic heart. This ganglion is thus a model for pacemaking and central pattern generation. Favorable anatomy has permitted voltage- and space-clamp analyses of voltage-dependent ionic currents that endow each neuron with the intrinsic ability to respond with rhythmical, patterned impulse activity to nonpatterned stimulation. The crustacean soma and initial axon segment do not support impulse generation but integrate input from stretch-sensitive dendrites and electrotonic and chemically mediated synapses on axonal processes in neuropils. The soma and initial axon produce a depolarization-activated, calcium-mediated, sustained potential, the "driver potential," so-called because it drives a train of impulses at the "trigger zone" of the axon. Extreme reliability results from redundancy and the electrotonic coupling and synaptic interaction among all the neurons. Complex modulation by central nervous system inputs and by neurohormones to adjust heart pumping to physiological demands has long been demonstrated, but much remains to be learned about the cellular and molecular mechanisms of action. The continuing relevance of the crustacean cardiac ganglion as a relatively simple model for pacemaking and central pattern generation is confirmed by the rapidly widening documentation of intrinsic potentials such as plateau potentials in neurons of all major animal groups. The suite of ionic currents (a slowly inactivating calcium current and various potassium currents, with variations) observed for the crustacean cardiac ganglion have been implicated in or proven to underlie a majority of the intrinsic potentials

Impact of heat processing on the detection of the major shellfish allergen tropomyosin in crustaceans and molluscs using specific monoclonal antibodies.

PubMed

Kamath, Sandip D; Abdel Rahman, Anas M; Komoda, Toshikazu; Lopata, Andreas L

2013-12-15

The major heat-stable shellfish allergen, tropomyosin, demonstrates immunological cross-reactivity, making specific differentiation of crustaceans and molluscs for food labelling very difficult. The aim of this study was to evaluate the application of allergen-specific monoclonal antibodies in differential detection of shellfish-derived tropomyosin in 11 crustacean and 7 mollusc species, and to study the impact of heating on its detection. Cross-reactive tropomyosin was detected in all crustacean species, with partial detection in molluscs: mussels, scallops and snails but none in oyster, octopus and squid. Furthermore, we have demonstrated that heating of shellfish has a profound effect on tropomyosin detection. This was evident by the enhanced recognition of multiple tropomyosin variants in the analysed shellfish species. Specific monoclonal antibodies, targetting the N-terminal region of tropomyosin, must therefore be developed to differentiate tropomyosins in crustaceans and molluscs. This can help in correct food labelling practices and thus protection of consumers. Copyright © 2013 Elsevier Ltd. All rights reserved.

Release of digestive enzymes from the crustacean hepatopancreas: effect of vertebrate gastrointestinal hormones.

PubMed

Resch-Sedlmeier, G; Sedlmeier, D

1999-06-01

Vertebrate gastrointestinal hormones were tested on their ability to liberate digestive enzymes from the crustacean midgut gland. CCK-8 (desulfated form), gastrin, bombesin, secretin, and substance P were detected to release enzymes. Maximal concentrations observed were 5 nM CCK for protease release, 1 nM gastrin for protease and 100 nM for amylase release, 100 nM bombesin for protease release, 10 nM secretin for amylase and protease release, and 100 nM substance P for protease release. Unlike in vertebrates, glucagon was unable to stimulate enzyme release in crustaceans, this also applies to the counterpart insulin. These results may support the assumption that Crustacea possess endogenous factors resembling the above mentioned vertebrate hormones, at least in such a way that the appropriate receptors have the capacity to accept these hormones.

The sensory dorsal organs of crustaceans.

PubMed

Lerosey-Aubril, Rudy; Meyer, Roland

2013-05-01

The cuticle of crustaceans bears numerous organs, of which the functions of many are unknown. One of these, the sensory dorsal organ (SDO), is present in a wide diversity of taxa. Here we critically review the variability, ultrastructure, distribution, and possible function of this enigmatic cuticular organ. Previous data are complemented by new observations on larvae and adults of various malacostracans. The SDO is composed of four sensors arranged as the corners of a square, the centre of which is occupied by a gland. Pores or pegs surrounding this central complex may also form part of the organ. The arrangement and the external aspect of the five main elements varies greatly, but this apparently has little impact on their ultrastructural organisation. The sensors and the gland are associated with a particularly thin cuticle. Each sensor contains four outer dendritic segments and the central gland is made of a single large cell. It is not yet known what this large cell secretes. The SDO is innervated from the tritocerebrum and therefore belongs to the third cephalic segment. A similar organ, here called the posterior SDO, has been repeatedly observed more posteriorly on the carapace. It resembles the SDO but has a greater number of sensors (usually six, but up to ten) apparently associated with only two outer dendritic segments. The SDO and the posterior SDO are known in the Eumalacostraca, the Hoplocarida, and the Phyllocarida. Some branchiopods also possess a 'dorsal organ' resembling both the SDO and the ion-transporting organ more typical of this group. This may indicate a common origin for these two functionally distinct groups of organs. New observations on the posterior SDO support the hypothesis that the SDO and the posterior SDO are homologous to the lattice organ complexes of the costracans. However, the relationship between the SDO and the dorsal cephalic hump of calanoid copepods remains unclear. No correlation can be demonstrated between the presence

Changes in abundance and spatial distribution of geese molting near Teshekpuk Lake, Alaska: Interspecific competition or ecological change?

USGS Publications Warehouse

Flint, Paul L.; Mallek, E.J.; King, R.J.; Schmutz, J.A.; Bollinger, K.S.; Derksen, D.V.

2008-01-01

Goose populations molting in the Teshekpuk Lake Special Area of the National Petroleum Reserve-Alaska have changed in size and distribution over the past 30 years. Black brant (Branta bernicla nigricans) are relatively stable in numbers but are shifting from large, inland lakes to salt marshes. Concurrently, populations of greater white-fronted geese (Anser albifrons frontalis) have increased seven fold. Populations of Canada geese (Branta canadensis and/or B. hutchinsii) are stable with little indication of distributional shifts. The lesser snow goose (Anser caerulescens caerulescens) population is proportionally small, but increasing rapidly. Coastline erosion of the Beaufort Sea has altered tundra habitats by allowing saltwater intrusion, which has resulted in shifts in composition of forage plant species. We propose two alternative hypotheses for the observed shift in black brant distribution. Ecological change may have altered optimal foraging habitats for molting birds, or alternatively, interspecific competition between black brant and greater white-fronted geese may be excluding black brant from preferred habitats. Regardless of the causative mechanism, the observed shifts in species distributions are an important consideration for future resource planning. ?? 2007 Springer-Verlag.

Experimental stress during molt suggests the evolution of condition-dependent and condition-independent ornaments in the king penguin.

PubMed

Schull, Quentin; Robin, Jean-Patrice; Dobson, F Stephen; Saadaoui, Hédi; Viblanc, Vincent A; Bize, Pierre

2018-01-01

Sexual selection and social selection are two important theories proposed for explaining the evolution of colorful ornamental traits in animals. Understanding signal honesty requires studying how environmental and physiological factors during development influence the showy nature of sexual and social ornaments. We experimentally manipulated physiological stress and immunity status during the molt in adult king penguins ( Aptenodytes patagonicus ), and studied the consequences of our treatments on colourful ornaments (yellow-orange and UV beak spots and yellow-orange auricular feather patches) known to be used in sexual and social contexts in this species. Whereas some ornamental features showed strong condition-dependence (yellow auricular feather chroma, yellow and UV chroma of the beak), others were condition-independent and remained highly correlated before and after the molt (auricular patch size and beak UV hue). Our study provides a rare examination of the links between ornament determinism and selection processes in the wild. We highlight the coexistence of ornaments costly to produce that may be honest signals used in mate choice, and ornaments for which honesty may be enforced by social mediation or rely on genetic constraints.

EFFECTS OF GAMMA RADIATION ON TWO DECAPOD CRUSTACEANS, PALAEMONETES PUGIO AND UCA PUGNAX

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

Rees, G.H.

1962-03-01

Experiments are described that were undertaken with the objective of determining the lethal dosages of gamma radiation, particularly the doses at which 50% succumb (LD/sub 50/), for 2 decapod crustaceans. (Pub. Health Eng. Abstr.)

AxIOM: Amphipod crustaceans from insular Posidonia oceanica seagrass meadows

PubMed Central

Heughebaert, André; Lepoint, Gilles

2016-01-01

Abstract Background The Neptune grass, Posidonia oceanica (L.) Delile, 1813, is the most widespread seagrass of the Mediterranean Sea. This foundation species forms large meadows that, through habitat and trophic services, act as biodiversity hotspots. In Neptune grass meadows, amphipod crustaceans are one of the dominant groups of vagile invertebrates, forming an abundant and diverse taxocenosis. They are key ecological components of the complex, pivotal, yet critically endangered Neptune grass ecosystems. Nevertheless, comprehensive qualitative and quantitative data about amphipod fauna found in Mediterranean Neptune grass meadows remain scarce, especially in insular locations. New information Here, we provide in-depth metadata about AxIOM, a sample-based dataset published on the GBIF portal. AxIOM is based on an extensive and spatially hierarchized sampling design with multiple years, seasons, day periods, and methods. Samples were taken along the coasts of Calvi Bay (Corsica, France) and of the Tavolara-Punta Coda Cavallo Marine Protected Area (Sardinia, Italy). In total, AxIOM contains 187 samples documenting occurrence (1775 records) and abundance (10720 specimens) of amphipod crustaceans belonging to 72 species spanning 29 families. The dataset is available at http://ipt.biodiversity.be/resource?r=axiom. PMID:27660521

Mechanisms of animal diapause: recent developments from nematodes, crustaceans, insects, and fish

PubMed Central

Denlinger, David L.; Podrabsky, Jason E.; Roy, Richard

2016-01-01

Life cycle delays are beneficial for opportunistic species encountering suboptimal environments. Many animals display a programmed arrest of development (diapause) at some stage(s) of their development, and the diapause state may or may not be associated with some degree of metabolic depression. In this review, we will evaluate current advancements in our understanding of the mechanisms responsible for the remarkable phenotype, as well as environmental cues that signal entry and termination of the state. The developmental stage at which diapause occurs dictates and constrains the mechanisms governing diapause. Considerable progress has been made in clarifying proximal mechanisms of metabolic arrest and the signaling pathways like insulin/Foxo that control gene expression patterns. Overlapping themes are also seen in mechanisms that control cell cycle arrest. Evidence is emerging for epigenetic contributions to diapause regulation via small RNAs in nematodes, crustaceans, insects, and fish. Knockdown of circadian clock genes in selected insect species supports the importance of clock genes in the photoperiodic response that cues diapause. A large suite of chaperone-like proteins, expressed during diapause, protects biological structures during long periods of energy-limited stasis. More information is needed to paint a complete picture of how environmental cues are coupled to the signal transduction that initiates the complex diapause phenotype, as well as molecular explanations for how the state is terminated. Excellent examples of molecular memory in post-dauer animals have been documented in Caenorhabditis elegans. It is clear that a single suite of mechanisms does not regulate diapause across all species and developmental stages. PMID:27053646

Mechanisms of animal diapause: recent developments from nematodes, crustaceans, insects, and fish.

PubMed

Hand, Steven C; Denlinger, David L; Podrabsky, Jason E; Roy, Richard

2016-06-01

Life cycle delays are beneficial for opportunistic species encountering suboptimal environments. Many animals display a programmed arrest of development (diapause) at some stage(s) of their development, and the diapause state may or may not be associated with some degree of metabolic depression. In this review, we will evaluate current advancements in our understanding of the mechanisms responsible for the remarkable phenotype, as well as environmental cues that signal entry and termination of the state. The developmental stage at which diapause occurs dictates and constrains the mechanisms governing diapause. Considerable progress has been made in clarifying proximal mechanisms of metabolic arrest and the signaling pathways like insulin/Foxo that control gene expression patterns. Overlapping themes are also seen in mechanisms that control cell cycle arrest. Evidence is emerging for epigenetic contributions to diapause regulation via small RNAs in nematodes, crustaceans, insects, and fish. Knockdown of circadian clock genes in selected insect species supports the importance of clock genes in the photoperiodic response that cues diapause. A large suite of chaperone-like proteins, expressed during diapause, protects biological structures during long periods of energy-limited stasis. More information is needed to paint a complete picture of how environmental cues are coupled to the signal transduction that initiates the complex diapause phenotype, as well as molecular explanations for how the state is terminated. Excellent examples of molecular memory in post-dauer animals have been documented in Caenorhabditis elegans It is clear that a single suite of mechanisms does not regulate diapause across all species and developmental stages. Copyright © 2016 the American Physiological Society.

Disease will limit future food supply from the global crustacean fishery and aquaculture sectors.

PubMed

Stentiford, G D; Neil, D M; Peeler, E J; Shields, J D; Small, H J; Flegel, T W; Vlak, J M; Jones, B; Morado, F; Moss, S; Lotz, J; Bartholomay, L; Behringer, D C; Hauton, C; Lightner, D V

2012-06-01

Seafood is a highly traded food commodity. Farmed and captured crustaceans contribute a significant proportion with annual production exceeding 10 M metric tonnes with first sale value of $40bn. The sector is dominated by farmed tropical marine shrimp, the fastest growing sector of the global aquaculture industry. It is significant in supporting rural livelihoods and alleviating poverty in producing nations within Asia and Latin America while forming an increasing contribution to aquatic food supply in more developed countries. Nations with marine borders often also support important marine fisheries for crustaceans that are regionally traded as live animals and commodity products. A general separation of net producing and net consuming nations for crustacean seafood has created a truly globalised food industry. Projections for increasing global demand for seafood in the face of level or declining fisheries requires continued expansion and intensification of aquaculture while ensuring best utilisation of captured stocks. Furthermore, continued pressure from consuming nations to ensure safe products for human consumption are being augmented by additional legislative requirements for animals (and their products) to be of low disease status. As a consequence, increasing emphasis is being placed on enforcement of regulations and better governance of the sector; currently this is a challenge in light of a fragmented industry and less stringent regulations associated with animal disease within producer nations. Current estimates predict that up to 40% of tropical shrimp production (>$3bn) is lost annually, mainly due to viral pathogens for which standard preventative measures (e.g. such as vaccination) are not feasible. In light of this problem, new approaches are urgently required to enhance yield by improving broodstock and larval sourcing, promoting best management practices by farmer outreach and supporting cutting-edge research that aims to harness the natural

Prevalence of Colacium vesiculosum (Colaciales: Euglenophyceae) on planktonic crustaceans in a subtropical shallow lake of Argentina.

PubMed

Zalocar, Yolanda; Frutos, Santa Margarita; Casco, Sylvina Lorena; Forastier, Marina Elizabet; Vallejos, Silvina Vanesa

2011-09-01

Colacium vesiculosum (Euglenophyceae) is an epibiont common on planktonic microcrustaceans of continental waters. The interaction between epibionts and substrate organisms is not very well known, particularly in subtropical environments of South America. In the present work, we analyzed the prevalence, density, biomass and attachment sites of C. vesiculosum on planktonic microcrustaceans from Paiva Lake, a subtropical lake of Argentina. With the aim to evaluate whether epibionts affect the filtering rates of Notodiaptomus spiniger, the dominant planktonic crustacean, we carried out bioassays using phytoplankton < 53 microm. Crustaceans were sampled using a PVC tube (1.2m long and 10cm in diameter), filtering 50L of water through a 53 microm-mesh. Microcrustaceans were counted in Bogorov chambers under a stereoscopic microscope. The infested organisms were separated and observed with a photonic microscope to determine density and biovolume of epibionts, by analyzing their distribution on the exoskeleton. The prevalence of C. vesiculosum was higher in adult crustaceans than in their larvae and juveniles. The most infested group was that of calanoid copepods, related to their high density. The attachment sites on the exoskeleton were found to be the portions of the body which have a higher probability of encounter with epibionts during locomotion and feeding, i.e., antennae and thoracic legs in copepods, and thoracic legs and postabdomen in cladocerans. The similar values found in the filtering rate of infested and uninfested individuals of N. spiniger and the constant prevalence (< 40%) of epibiont algae, suggest that C. vesiculosum does not condition the life of planktonic crustaceans of Paiva Lake.

[Crustaceans associated to macroalgae in Bajo Pepito, Isla Mujeres, Mexican Caribbean].

PubMed

Campos Vázquez, C

2000-01-01

Crustaceans associated with macroalgae were collected for one year by scuba diving in Bajo Pepito, Isla Mujeres, mexican Caribbean. A total of 148 organisms were found: three orders, 11 families, 18 genera and 19 species in nine types of associations. The order with highest abundance was Isopoda (112), followed by Amphipoda (20) and Decapoda (16).

Inorganic Biominerals in Crustaceans are Structurally Independent of Organic Framework

NASA Astrophysics Data System (ADS)

Mergelsberg, S. T.; Michel, F. M.; Mukhopadhyay, B.; Dove, P. M.

2015-12-01

Biomineralization of calcium carbonate (CaCO3) as crystalline calcite or amorphous CaCO3 (ACC) occurs in the exoskeletons of all crustaceans. These cuticles are complex composites of inorganic mineral and organic macromolecules with highly divergent morphologies that are adapted to the extreme variations in environmental pressures within their diverse ecological niches. The remarkable variations and adaptations that form, infer a highly efficient and regulated mechanism for biomineralization that is most likely orchestrated by a myriad of biomacromolecules (Ziegler A 2012). The roles of these peptides and organic metabolites during CaCO3 biomineralization are not well understood. In part, this is due to a lack of knowledge of crustacean homeostasis. In a step toward understanding cuticle mineralization in crustaceans, this study asks: Which molecules affect biomineralization? Do the biomineral-active molecules vary greatly between species and body parts? Recent studies of polysaccharide controls on mineralization also raise the question of whether small heterogeneities in chitin, the most abundant biopolymer of the composite, could be primarily responsible for differences in CaCO3 crystallinity. This study used a novel spectroscopic approach to characterize the mineral and organic components of exoskeletons from three Malacostraca organisms — American Lobster (Homarus americanus), Dungeness Crab (Metacarcinus magister), and Red Rock Crab (Cancer productus). Using high-energy x-ray diffraction and Raman spectroscopy, the cuticles of three major body parts from these organisms were analyzed for the structure and bulk chemistry of its chitin and CaCO3 components. The findings indicate that Raman spectroscopy provides adequate resolution to show that crystallinity of chitin and the CaCO3 mineral component are chemically independent of each other, although their crystallinities co-vary for Brachyura species (Dungeness and Red Rock Crabs). Insights from this study

Sexual Contests in Aquatic Crustaceans: What's Physiology Got To Do with It?

ERIC Educational Resources Information Center

Keogh, Daniel P.; Sparkes, Timothy C.

2003-01-01

Describes a science laboratory on reproductive behavior and studies the dynamics in Lirceus, an aquatic crustacean of which the females evaluate the males' quality through mating contests. Explains collecting isopods and developing colonies in the lab environment. Investigates food deprivation, locomotor activity, and behavioral trials to…

A TALE of shrimps: Genome-wide survey of homeobox genes in 120 species from diverse crustacean taxa.

PubMed

Chang, Wai Hoong; Lai, Alvina G

2018-01-01

The homeodomain-containing proteins are an important group of transcription factors found in most eukaryotes including animals, plants and fungi. Homeobox genes are responsible for a wide range of critical developmental and physiological processes, ranging from embryonic development, innate immune homeostasis to whole-body regeneration. With continued fascination on this key class of proteins by developmental and evolutionary biologists, multiple efforts have thus far focused on the identification and characterization of homeobox orthologs from key model organisms in attempts to infer their evolutionary origin and how this underpins the evolution of complex body plans. Despite their importance, the genetic complement of homeobox genes has yet been described in one of the most valuable groups of animals representing economically important food crops. With crustacean aquaculture being a growing industry worldwide, it is clear that systematic and cross-species identification of crustacean homeobox orthologs is necessary in order to harness this genetic circuitry for the improvement of aquaculture sustainability. Using publicly available transcriptome data sets, we identified a total of 4183 putative homeobox genes from 120 crustacean species that include food crop species, such as lobsters, shrimps, crayfish and crabs. Additionally, we identified 717 homeobox orthologs from 6 other non-crustacean arthropods, which include the scorpion, deer tick, mosquitoes and centipede. This high confidence set of homeobox genes will now serve as a key resource to the broader community for future functional and comparative genomics studies.

Absence of preserved glucosamine and amino acids in fossil crustacean exoskeletons

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

Schimmelmann, A.; Krause, R.G.F.; DeNiro, M.J.

1988-01-01

No glucosamine and only traces of amino acids were detected in kerogen prepared from fossil crustacean exoskeletons. The elemental C/N ratios of the kerogen samples were above 20, indicating that most of the organic nitrogen was eliminated from the chitin biopolymer during diagenesis. The results contradict earlier reports of the stability of chitin during fossilization.

Arsenic speciation and spatial and interspecies differences of metal concentrations in mollusks and crustaceans from a South China estuary.

PubMed

Zhang, Wei; Wang, Wen-Xiong; Zhang, Li

2013-05-01

Arsenic speciation and concentrations were determined in mollusks and crustaceans in the intertidal zone from twelve locations in Zhanjiang estuary, South China. Metal concentrations (Ag, As, Cd, Cu, Hg, Ni, Pb, and Zn) were also concurrently determined in these species. Arsenic speciation analysis showed that the less-toxic arsenobetaine (AsB) constituted 80.6-98.8 % of all As compounds, and dimethylarsinic acid (DMA) constituted 0.47-3.44 %. Monomethylarsonic acid (MMA) and As(V) were only detected in the whelk Drupa fiscella and the crab Heteropilumnus ciliatus, respectively. Arsenite [As(III)] was not detected in any of the sampled specimens, but there were also unidentified other As species. A strong spatial variation of metals in the oyster Saccostrea cucullata was found in the estuary, confirming that oysters can be used as a good biomonitor of metal contamination in the studied area. The concentrations of eight metals in the studied mollusks and crustaceans clearly revealed that these invertebrates accumulated different metals to different degrees. Furthermore, As, Cd, Cu, Hg, and Pb contents in mollusks and crustacean samples were below the Food and Agricultural Organization (FAO) safe concentrations, thus there was no obvious health risk from the intake of the metals through marine mollusks and crustaceans consumption.

76 FR 77214 - Hawaii Crustacean Fisheries; 2012 Northwestern Hawaiian Islands Lobster Harvest Guideline

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-12

... Crustacean Fisheries; 2012 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine...: Notification of lobster harvest guideline. SUMMARY: NMFS establishes the annual harvest guideline for the commercial lobster fishery in the Northwestern Hawaiian Islands (NWHI) for calendar year 2012 at zero...

76 FR 4551 - Hawaii Crustacean Fisheries; 2011 Northwestern Hawaiian Islands Lobster Harvest Guideline

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-26

...-XA159 Hawaii Crustacean Fisheries; 2011 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY.... ACTION: Notification of lobster harvest guideline. SUMMARY: NMFS announces that the annual harvest guideline for the commercial lobster fishery in the Northwestern Hawaiian Islands (NWHI) for calendar year...

78 FR 9327 - Hawaii Crustacean Fisheries; 2013 Northwestern Hawaiian Islands Lobster Harvest Guideline

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-08

...-XC453 Hawaii Crustacean Fisheries; 2013 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY.... ACTION: Notification of lobster harvest guideline. SUMMARY: NMFS establishes the annual harvest guideline for the commercial lobster fishery in the Northwestern Hawaiian Islands (NWHI) for calendar year 2013...

Silver nanoparticles exhibit size-dependent differential toxicity and induce expression of syncytin-1 in FA-AML1 and MOLT-4 leukaemia cell lines.

PubMed

Alqahtani, Sultan; Promtong, Pawika; Oliver, Anthony W; He, Xiaotong T; Walker, Thomas D; Povey, Andrew; Hampson, Lynne; Hampson, Ian N

2016-11-01

Human endogenous retrovirus (HERV) sequences make up ~8% of the human genome and increased expression of some HERV proteins has been observed in various pathologies including leukaemia and multiple sclerosis. However, little is known about the function of these HERV proteins or environmental factors which regulate their expression. Silver nanoparticles (AgNPs) are used very extensively as antimicrobials and antivirals in numerous consumer products although their effect on the expression of HERV gene products is unknown. Cell proliferation and cell toxicity assays were carried out on human acute T lymphoblastic leukaemia (MOLT-4) and Fanconi anaemia associated acute myeloid leukaemia (FA-AML1) cells treated with two different sizes of AgNPs (7nm and 50nm diameter). Reverse-transcriptase polymerase chain reaction and western blotting were then used to the assess expression of HERV-W syncytin-1 mRNA and protein in these cells. FA-AML1 cells were more sensitive overall than MOLT-4 to treatment with the smaller 7nm sized AgNp's being the most toxic in these cells. MOLT-4 cell were more resistant and showed no evidence of differential toxicity to the different sized particles. Syncytin-1 mRNA and protein were induced by both 7 and 50nm AgNPs in both cell types yet with different kinetics. In summary, the observation that AgNPs induce expression of syncytin-1 in FA-AML1 and MOLT-4 cells at doses as little as 5 µg/ml is grounds for concern since this protein is up-regulated in both malignant and neurodegenerative diseases. Considering the widespread use of AgNPs in the environment it is clear that their ability to induce syncytin-1 should be investigated further in other cell types. © The Author 2016. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Identification and Characterization of an Insulin-Like Receptor Involved in Crustacean Reproduction.

PubMed

Sharabi, O; Manor, R; Weil, S; Aflalo, E D; Lezer, Y; Levy, T; Aizen, J; Ventura, T; Mather, P B; Khalaila, I; Sagi, A

2016-02-01

Sexual differentiation and maintenance of masculinity in crustaceans has been suggested as being regulated by a single androgenic gland (AG) insulin-like peptide (IAG). However, downstream elements involved in the signaling cascade remain unknown. Here we identified and characterized a gene encoding an insulin-like receptor in the prawn Macrobrachium rosenbergii (Mr-IR), the first such gene detected in a decapod crustacean. In mining for IRs and other insulin signaling-related genes, we constructed a comprehensive M. rosenbergii transcriptomic library from multiple sources. In parallel we sequenced the complete Mr-IR cDNA, confirmed in the wide transcriptomic library. Mr-IR expression was detected in most tissues in both males and females, including the AG and gonads. To study Mr-IR function, we performed long-term RNA interference (RNAi) silencing in young male prawns. Although having no effect on growth, Mr-IR silencing advanced the appearance of a male-specific secondary trait. The most noted effects of Mr-IR silencing were hypertrophy of the AG and the associated increased production of Mr-IAG, with an unusual abundance of immature sperm cells being seen in the distal sperm duct. A ligand blot assay using de novo recombinant Mr-IAG confirmed the existence of a ligand-receptor interaction. Whereas these results suggest a role for Mr-IR in the regulation of the AG, we did not see any sexual shift after silencing of Mr-IR, as occurred when the ligand-encoding Mr-IAG gene was silenced. This suggests that sexual differentiation in crustaceans involve more than a single Mr-IAG receptor, emphasizing the complexity of sexual differentiation and maintenance.

Population variation in isotopic composition of shorebird feathers: Implications for determining molting grounds

USGS Publications Warehouse

Torres-Dowdall, J.; Farmer, A.H.; Bucher, E.H.; Rye, R.O.; Landis, G.

2009-01-01

Stable isotope analyses have revolutionized the study of migratory connectivity. However, as with all tools, their limitations must be understood in order to derive the maximum benefit of a particular application. The goal of this study was to evaluate the efficacy of stable isotopes of C, N, H, O and S for assigning known-origin feathers to the molting sites of migrant shorebird species wintering and breeding in Argentina. Specific objectives were to: 1) compare the efficacy of the technique for studying shorebird species with different migration patterns, life histories and habitat-use patterns; 2) evaluate the grouping of species with similar migration and habitat use patterns in a single analysis to potentially improve prediction accuracy; and 3) evaluate the potential gains in prediction accuracy that might be achieved from using multiple stable isotopes. The efficacy of stable isotope ratios to determine origin was found to vary with species. While one species (White-rumped Sandpiper, Calidris fuscicollis) had high levels of accuracy assigning samples to known origin (91% of samples correctly assigned), another (Collared Plover, Charadrius collaris) showed low levels of accuracy (52% of samples correctly assigned). Intra-individual variability may account for this difference in efficacy. The prediction model for three species with similar migration and habitat-use patterns performed poorly compared with the model for just one of the species (71% versus 91% of samples correctly assigned). Thus, combining multiple sympatric species may not improve model prediction accuracy. Increasing the number of stable isotopes in the analyses increased the accuracy of assigning shorebirds to their molting origin, but the best combination - involving a subset of all the isotopes analyzed - varied among species.

Late Devonian (Frasnian) phyllopod and phyllocarid crustacean shields from Belgium reinterpreted as ammonoid anaptychi

NASA Astrophysics Data System (ADS)

Goolaerts, Stijn; Denayer, Julien; Mottequin, Bernard

2017-12-01

The taxonomic affinities of fossils from the Frasnian succession of Belgium previously described as phyllopod and phyllocarid crustacean shields are discussed. The rediscovery of the holotype of Ellipsocaris dewalquei, the type species of the genus Ellipsocaris Woodward in Dewalque, 1882, allows to end the discussion on the taxonomic assignation of the genus Ellipsocaris. It is removed from the phyllopod crustaceans as interpreted originally and considered here as an ammonoid anaptychus. Furthermore, it is considered to be a junior synonym of the genus Sidetes Giebel, 1847. Similarly, Van Straelen's (1933) lower to middle Frasnian record Spathiocaris chagrinensis Ruedemann, 1916, is also an ammonoid anaptychus. Although ammonoids can be relatively frequent in some Frasnian horizons of Belgium, anaptychi remain particularly scarce and the attribution to the present material to peculiar ammonoid species is not possible.

THE INFLUENCE OF INSECT JUVENILE HORMONE AGONISTTS ON METAMORPHOSIS AND REPRODUCTION IN ESTUARINE CRUSTACEANS

EPA Science Inventory

Comparative developmental and reproductive studies were performed on several species of estuarine crustaceans in response to three juvenile hormone agonists (JHAs) (methoprene, fenoxycarb, and pyriproxyfen). Larval development of the grass shrimp, Palaemonetes pugio, was greater ...

Crustaceans from bitumen clast in Carboniferous glacial diamictite extend fossil record of copepods.

PubMed

Selden, Paul A; Huys, Rony; Stephenson, Michael H; Heward, Alan P; Taylor, Paul N

2010-08-10

Copepod crustaceans are extremely abundant but, because of their small size and fragility, they fossilize poorly. Their fossil record consists of one Cretaceous (c. 115 Ma) parasite and a few Miocene (c. 14 Ma) fossils. In this paper, we describe abundant crustacean fragments, including copepods, from a single bitumen clast in a glacial diamictite of late Carboniferous age (c. 303 Ma) from eastern Oman. Geochemistry identifies the source of the bitumen as an oilfield some 100-300 km to the southwest, which is consistent with an ice flow direction from glacial striae. The bitumen likely originated as an oil seep into a subglacial lake. This find extends the fossil record of copepods by some 188 Ma, and of free-living forms by 289 Ma. The copepods include evidence of the extant family Canthocamptidae, believed to have colonized fresh water in Pangaea during Carboniferous times.

Neuropeptide Signaling in Crustaceans Probed by Mass Spectrometry

NASA Astrophysics Data System (ADS)

Liang, Zhidan

Neuropeptides are one of the most diverse classes of signaling molecules whose identities and functions are not yet fully understood. They have been implicated in the regulation of a wide range of physiological processes, including feeding-related and motivated behaviors, and also environmental adaptations. In this work, improved mass spectrometry-based analytical platforms were developed and applied to the crustacean systems to characterize signaling molecules. This dissertation begins with a review of mass spectrometry-based neuropeptide studies from both temporal- and spatial-domains. This review is then followed by several chapters detailing a few research projects related to the crustacean neuropeptidomic characterization and comparative analysis. The neuropeptidome of crayfish, Orconectes rusticus is characterized for the first time using mass spectrometry-based tools. In vivo microdialysis sampling technique offers the capability of direct sampling from extracellular space in a time-resolved manner. It is used to investigate the secreted neuropeptide and neurotransmitter content in Jonah crab, Cancer borealis, in this work. A new quantitation strategy using alternative mass spectrometry data acquisition approach is developed and applied for the first time to quantify neuropeptides. Coupling of this method with microdialysis enables the study of neuropeptide dynamics concurrent with different behaviors. Proof-of-principle experiments validating this approach have been carried out in Jonah crab, Cancer borealis to study feeding- and circadian rhythm-related neuropeptide changes using micoridialysis in a time-resolved manner. This permits a close correlation between behavioral and neurochemical changes, providing potential candidates for future validation of regulatory roles. In addition to providing spatial information, mass spectrometry imaging (MSI) technique enables the characterization of signaling molecules while preserving the temporal resolution. A

Transboundary movement of shrimp viruses in crustaceans and their products: a special risk?

PubMed

Jones, Brian

2012-06-01

Shrimp and shrimp products form the most valuable internationally traded fisheries commodity, and the volumes are huge, estimated to be about 3.6 million tonnes. However, despite the existence under the General Agreement on Tariffs and Trade, of the Sanitary and Phytosanitary Measures (SPS Agreement) and the activities of the World Organisation for Animal Health (OIE), viral shrimp epizootics have spread and continue to spread, affecting world production. Though most attention has focussed on the movement of live shrimp product, the spread of new and emerging diseases through other crustaceans and their nonviable products is of increasing concern. The risks associated with the unrestricted movement of nonviable product will be outlined and measures that can be taken to mitigate the risk are discussed. Ultimately, for crustacean diseases, the paradigm under which the OIE has operated for the past 80 years needs to change. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

75 FR 1597 - Western Pacific Crustacean Fisheries; 2010 Northwestern Hawaiian Islands Lobster Harvest Guideline

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-12

... Pacific Crustacean Fisheries; 2010 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY.... ACTION: Notification of lobster harvest guideline. SUMMARY: NMFS announces that the annual harvest guideline for the commercial lobster fishery in the Northwestern Hawaiian Islands (NWHI) for calendar year...

The complete mitochondrial genome of the stomatopod crustacean Squilla mantis

PubMed Central

Cook, Charles E

2005-01-01

Background Animal mitochondrial genomes are physically separate from the much larger nuclear genomes and have proven useful both for phylogenetic studies and for understanding genome evolution. Within the phylum Arthropoda the subphylum Crustacea includes over 50,000 named species with immense variation in body plans and habitats, yet only 23 complete mitochondrial genomes are available from this subphylum. Results I describe here the complete mitochondrial genome of the crustacean Squilla mantis (Crustacea: Malacostraca: Stomatopoda). This 15994-nucleotide genome, the first described from a hoplocarid, contains the standard complement of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a non-coding AT-rich region that is found in most other metazoans. The gene order is identical to that considered ancestral for hexapods and crustaceans. The 70% AT base composition is within the range described for other arthropods. A single unusual feature of the genome is a 230 nucleotide non-coding region between a serine transfer RNA and the nad1 gene, which has no apparent function. I also compare gene order, nucleotide composition, and codon usage of the S. mantis genome and eight other malacostracan crustaceans. A translocation of the histidine transfer RNA gene is shared by three taxa in the order Decapoda, infraorder Brachyura; Callinectes sapidus, Portunus trituberculatus and Pseudocarcinus gigas. This translocation may be diagnostic for the Brachyura. For all nine taxa nucleotide composition is biased towards AT-richness, as expected for arthropods, and is within the range reported for other arthropods. Codon usage is biased, and much of this bias is probably due to the skew in nucleotide composition towards AT-richness. Conclusion The mitochondrial genome of Squilla mantis contains one unusual feature, a 230 base pair non-coding region has so far not been described in any other malacostracan. Comparisons with other Malacostraca show that all

Ultrastructure and development of the new stylets inside pre-molting first instar nymphs of the Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae)

USDA-ARS?s Scientific Manuscript database

The ultrastructure and development of new stylets was studied in pre-molting first instar nymph of Diaphorina citri. Two oval-shaped masses of cuboidal hypodermal cells, located in the cephalic region, had long extensions that ended with developing pairs of mandibular and maxillary stylets, apparent...

Cell cycle effect on the activity of deoxynucleoside analogue metabolising enzymes

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

Fyrberg, Anna; Albertioni, Freidoun; Lotfi, Kourosh

Deoxynucleoside analogues (dNAs) are cytotoxic towards both replicating and indolent malignancies. The impact of fluctuations in the metabolism of dNAs in relation to cell cycle could have strong implications regarding the activity of dNAs. Deoxycytidine kinase (dCK) and deoxyguanosine kinase (dGK) are important enzymes for phosphorylation/activation of dNAs. These drugs can be dephosphorylated/deactivated by 5'-nucleotidases (5'-NTs) and elevated activities of 5'-NTs and decreased dCK and/or dGK activities represent resistance mechanisms towards dNAs. The activities of dCK, dGK, and three 5'-NTs were investigated in four human leukemic cell lines in relationship to cell cycle progression and cytotoxicity of dNAs. Synchronization ofmore » cell cultures to arrest in G0/G1 by serum-deprivation was performed followed by serum-supplementation for cell cycle progression. The activities of dCK and dGK increased up to 3-fold in CEM, HL60, and MOLT-4 cells as they started to proliferate, while the activity of cytosolic nucleotidase I was reduced in proliferating cells. CEM, HL60, and MOLT-4 cells were also more sensitive to cladribine, cytarabine, 9-{beta}-D-arabinofuranosylguanine and clofarabine than K562 cells which demonstrated lower levels and less alteration of these enzymes and were least susceptible to the cytotoxic effects of most dNAs. The results suggest that, in the cell lines studied, the proliferation process is associated with a general shift in the direction of activation of dNAs by inducing activities of dCK/dGK and reducing the activity of cN-I which is favourable for the cytotoxic effects of cladribine, cytarabine and, 9-{beta}-D-arabinofuranosylguanine. These results emphasize the importance of cellular proliferation and dNA metabolism by both phosphorylation and dephosphorylation for susceptibility to dNAs. It underscores the need to understand the mechanisms of action and resistance to dNAs in order to increase efficacy of dNAs treatment by new

POLYCLONAL ANTISERA AGAINST ESTUARINE CRUSTACEAN VITELLINS: A MOLECULAR APPROACH TO REPRODUCTIVE ENDOCRINOLOGY AND TOXICOLOGY

EPA Science Inventory

To fully elucidate the action of crustacean hormones, or their agonists, on reproduction and vitellogenesis it has become increasingly important to develop sensitive assays that indicate a stimulatory or inhibitory effect on easily measured endpoints. Because of the relative abun...

POLYCLONAL ANTISERA AGAINST ESTUARINE CRUSTACEAN VITELLINS: A MOLECULAR APPROACH TO REPRODUCTIVE ENDOCRINOLOGY AND TOXICOLOGY.

EPA Science Inventory

To fully elucidate the action of crustacean hormones, or their agonists, on vitellogenesis and reproduction, it has become increasingly important to develop sensitive assays that indicate a stimulatory or inhibitory effect on easily measured endpoints. Because of the relative ab...

Crustacean communities in coastal ephemeral pools in the Araucanía region (38° S, Chile).

PubMed

De Los Ríos-Escalante, P; Acevedo, P

2016-01-01

The fauna communities of ephemeral pools in southern Chile are characterized by heterogeneity of crustacean taxa; nevertheless, no detailed studies exist of their community structure. The aim of the present study was to analyze the crustacean community structure in two groups of ephemeral pools (Puaucho and Nigue pools) in the coastal zone of the Araucanía region. A correlation matrix was made by species abundance against temperature, conductivity, pH and total dissolved solids. In a second step, a null model for species co-occurrence was applied to the total data and to each group. The results for total data revealed a significant direct relation between the abundance of H. costera, C. dubia and Mesocyclops. For the Puaucho pools, the same results were found together with direct associations with total dissolved solids, conductivity and pH. Finally, different results were found for the Nigue pools, with no clear significant associations, either direct or indirect, between the abundance of different crustacean taxa and abiotic parameters. These results were supported by the co-occurrence null model analysis, which revealed the presence of regulator factors for the total data, and for each of the two groups. Ecological topics are discussed with emphasis on meta-community dynamics.

CYP450s analysis across spiny lobster metamorphosis identifies a long sought missing link in crustacean development.

PubMed

Ventura, Tomer; Bose, Utpal; Fitzgibbon, Quinn P; Smith, Gregory G; Shaw, P Nicholas; Cummins, Scott F; Elizur, Abigail

2017-07-01

Cytochrome P450s (CYP450s) are a rapidly evolving family of enzymes, making it difficult to identify bona fide orthologs with notable lineage-specific exceptions. In ecdysozoans, a small number of the most conserved orthologs include enzymes which metabolize ecdysteroids. Ecdysone pathway components were recently shown in a decapod crustacean but with a notable absence of shade, which is important for converting ecdysone to its active form, 20-hydroxyecdysone (20HE), suggesting that another CYP450 performs a similar function in crustaceans. A CYPome temporal expression analysis throughout metamorphosis performed in this research highlights several un-annotated CYP450s displaying differential expression and provides information into expression patterns of annotated CYP450s. Using the expression patterns in the Eastern spiny lobster Sagmariasus verreauxi, followed by 3D modelling and finally activity assays in vitro, we were able to conclude that a group of CYP450s, conserved across decapod crustaceans, function as the insect shade. To emphasize the fact that these genes share the function with shade but are phylogenetically distinct, we name this enzyme system Shed. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

External morphology of Lightiella monniotae (Crustacea, Cephalocarida) in the light of Cambrian 'Orsten' crustaceans.

PubMed

Olesen, Jørgen; Haug, Joachim T; Maas, Andreas; Waloszek, Dieter

2011-09-01

The species-poor meiofaunal Cephalocarida have played an important role in discussions of the phylogeny and evolution of Crustacea since their discovery in 1955. One reason may be that the morphology of cephalocarids includes some aspects of putatively ancient appearance, such as the simple roof-shaped head shield, the anterior three head appendages resembling those of a nauplius larva, or the trunk-limb-like second maxilla. Cephalocarida have even been suggested to represent the sister taxon to all other Eucrustacea. Presence of possibly plesiomorphic characters, however, does not necessarily point to a basal position in the system. Growing evidence demonstrates that the modification of the fourth post-antennular cephalic appendage, the 'maxilla', into a "mouth part" may have occurred independently in the different eucrustacean lineages, so a trunk-limb-like maxilla is an ancient feature that does not hold only for cephalocarids. Retention of its plesiomorphic shape and function in the Cephalocarida remains, however, noteworthy. Cephalocarids are still little studied and incompletely known, especially their external morphology. By examining several adults and one young specimen of Lightiella monniotae Cals and Delamare Deboutteville, 1970 from New Caledonia, we aimed to a) document as many details as possible, and b) compare these data with other species of Cephalocarida. We also aimed to reconstruct aspects of the ground pattern of Cephalocarida, which is a pre-requisite for any comparisons in a broader perspective of crustacean phylogeny. Among the new findings or conclusions are: (1) Lightiella is in need of a revision since several assumed differences between the species are questionable or subject to intra-specific variability; (2) the cuticle of the trunk-limb basipod is sub-divided into a number of smaller sclerotized areas as in various exceptionally 3D preserved fossil crustaceans from Cambrian 'Orsten' faunal assemblages; (3) a small transitional portion

Alloxenic distribution of cystacanths of two Profilicollis species in sympatric crustacean hosts in Chile.

PubMed

Balboa, L; Hinojosa, A; Riquelme, C; Rodríguez, S; Bustos, J; George-Nascimento, M

2009-10-01

The taxonomic status of Profilicollis ( = Falsifilicollis Webster, 1948) species in crustaceans in Chile is examined. Mole crabs, Emerita analoga (Stimpson 1857), living in the splash zone of a sandy beach at Lenga off the coast of central Chile, harbor Polymorphus (Profilicollis) bullocki Mateo, Córdova and Guzmán 1982, while the estuarine crabs, Hemigrapsus crenulatus (Milne-Edwards, 1837), living in an oligohaline inlet at the same site, harbor Profilicollis spp. cystacanths which cannot be distinguished specifically to either Profilicollis antarcticus or P. chasmagnathi Holcman-Spector, Mañé-Garzón and Dei-Cas 1977. We found no morphological data supporting records of P. altmani along the coast of Chile. Therefore, and after examination of both their morphology and the literature, we consider that P. bullocki must be reinstated as a valid species in the genus. There is a widespread distribution of habitats, such as sandy beaches and inlets, as well as a variety of host taxa involved in the life cycle of Profilicollis spp. Consequently, they provide an interesting scenario for testing hypotheses regarding the coevolution and host specificity of these parasites.

Mercury correlations among blood, muscle, and hair of northern elephant seals during the breeding and molting fasts

USGS Publications Warehouse

Peterson, Sarah; Ackerman, Joshua T.; Costa, Daniel P.

2016-01-01

Mercury (Hg) biomonitoring and toxicological risk assessments for marine mammals commonly sample different tissues, making comparisons to toxicity benchmarks and among species and regions difficult. Few studies have examined how life history events, such as fasting, influence the relationship between total Hg (THg) concentrations in different tissues. We evaluated the relationships between THg concentrations in blood, muscle, and hair of female and male northern elephant seals (Mirounga angustirostris) at the start and end of the breeding and molting fasts. The relationships between tissues varied among tissue pairs and differed by sampling period and sex. Blood and muscle were generally related at all time periods; however, hair, an inert tissue, did not strongly represent the metabolically active tissues (blood and muscle) at all times of year. The strongest relationships between THg concentrations in hair and those in blood or muscle were observed during periods of active hair growth (end of the molting period) or during time periods when internal body conditions were similar to those when the hair was grown (end of the breeding fast). Our results indicate that THg concentrations in blood or muscle can be translated to the other tissue type using the equations we developed, but that THg concentrations in hair were generally a poor index of internal THg concentrations except during the end of fasting periods.

EFFECT OF VARYING INCUBATION PERIODS ON CYTOTOXICITY AND VIRUCIDAL ACTIVITIES OF Justicia gendarussa Burm.f. LEAF EXTRACT ON HIV-INFECTED MOLT-4 CELLS.

PubMed

Widiyanti, Prihartini; Prajogo, Bambang; Widodo, Agustinus

2018-01-01

Justicia gendarussa Burm.f. has an anti-HIV activity. This study was conducted to evaluate the effects of incubation periods on the cytotoxicity and virucidal activities of the J. gendarussa leaves extract on MOLT-4 cells. The cytotoxicity assay was evaluated by using the WST-1 test with incubation periods of 3 days and 5 days. The virucidal activity test was determined by measuring the inhibitory activities on the syncytium formation. The cytotoxicity assay showed the value of CC 50 on MOLT-4 cell culture with the test material of 70% ethanol extract of J. gendarussa leaves as much as 3928.620 µg /mL and 3176.581 µg /mL (incubation day 3 and day 5, respectively); fractionated-70% ethanol extract = 81782.428 µg /mL and 12175.870 µg/mL; and water extract = 16372.689 µg/mL and 2946.117 µg/mL. The test results of the virucidal activities (inhibit ≥ 90% the formation of syncytium) of 70% ethanol extract of J. gendarussa leaves is at a concentration 250 µg/mL, 500 µg/mL and 1000 µg/mL (3-day incubation) and 250 µg/mL (5-day incubation); and fractionated-70% ethanol extract at a concentration 250 µg /mL, 500 µg/mL and 1000 µg/mL (3-day incubation) and 1000 µg/mL (5-day incubation). 70% ethanol extract, fractionated-70% ethanol extract, and water extract of J. gendarussa leaves were relatively nontoxic toward MOLT-4 cells, and fractionated-70% ethanol extract had better potentials in virucidal activities.

Tubular localization of silent calcium channels in crustacean skeletal muscle fibers.

PubMed

Monterrubio, J; Ortiz, G; Orkand, P M; Zuazaga, C

2002-01-01

Ca2+-induced Ca2+ release (CICR) in the superficial abdominal flexor muscle of the crustacean Atya lanipes appears to be mediated by a local control mechanism similar to that of vertebrate cardiac muscle, but with an unusually high gain. Thus, Ca2+ influx increases sufficiently the local concentration of Ca2+ in the immediate vicinity of the sarcoplasmic reticulum Ca2+ release channels to trigger the highly amplified release of Ca2+ required for contraction, but is too low to generate a macroscopic inward current (i.e., the Ca2+ channels are silent). To determine the localization of the silent Ca2+ Channels, the mechanical, electrophysiological and ultrastructural properties of the muscle were examined before and after formamide treatment, a procedure that produces the disruption of transverse tubules of striated muscle. We found that tubular disruption decreased tension generation by about 90%; reduced inward current (measured as Vmax, the maximum rate of rise of Sr2+ action potentials) by about 80%; and decreased membrane capacitance by about 77%. The results suggest that ca. 80% of the silent Ca2+ channels are located in the tubular system. Thus, these studies provide further evidence to support the local control mechanism of CICR in crustacean skeletal muscle.

Effects of a social cue on reproductive development and pre-alternate molt in seasonally breeding migrant and resident female songbirds (Zonotrichia leucophrys).

PubMed

Chmura, Helen E; Meddle, Simone L; Wingfield, John C; Hahn, Thomas P

2017-08-15

To time reproduction optimally, birds have evolved diverse mechanisms by which they respond to environmental changes that help them anticipate and prepare for the breeding season. While residents initiate reproductive preparation and breed in the same geographic location, migrant birds simultaneously prepare for breeding and migration far from their breeding grounds. As a result, it is hypothesized that migrant and resident birds use environmental cues differently to prepare to breed and that there is adaptive specialization in mechanisms regulating reproductive preparation. Specifically, residents are expected to rely more on non-photic cues (e.g. food, temperature, social cues) than migrants. We tested this general prediction using a social cue manipulation. First, we compared the effects of subspecies-appropriate recorded male song on reproductive development in migrants and residents on a naturally increasing photoperiod. Second, we tested the sensitivity of migrant-specific life history events (fattening and pre-alternate molt) to song treatment. After 82 days, residents had higher luteinizing hormone and greater ovarian development than migrants, but song treatment had no effect on these metrics in either subspecies. Song advanced pre-alternate molt but had no effect on fattening in migrants. While our study does not support specialization in social cue use in migrants and residents, it is consistent with findings in the literature of specialization in photoperiodic response. It also demonstrates for the first time that social cues can influence molt in a migrant species. Additional findings from a pilot study looking at responses to a live male suggest it is important to test other kinds of social cues. © 2017. Published by The Company of Biologists Ltd.

Molecular characterization, antibiotic resistance pattern and biofilm formation of Vibrio parahaemolyticus and V. cholerae isolated from crustaceans and humans.

PubMed

Ahmed, Heba A; El Bayomi, Rasha M; Hussein, Mohamed A; Khedr, Mariam H E; Abo Remela, Etab M; El-Ashram, Ahmed M M

2018-06-02

Human infection with pathogenic vibrios is associated with contaminated seafood consumption. In the present study, we examined 225 crustaceans collected from retail markets in Egypt. Stool samples from gastroenteritis patients were also examined. Bacteriological and molecular examinations revealed 34 (15.1%) V. parahaemolyticus and 2 (0.9%) V. cholerae from crustaceans, while V. parahaemolyticus isolates were identified in 3 (3%) of the human samples. The virulence-associated genes tdh and/or trh were detected in 5.9% and 100% of the crustacean and human samples, respectively, whereas the two V. cholerae isolates were positive for the ctx and hlyA genes. Antibiotic sensitivity revealed high resistance of the isolates to the used antibiotics and an average MAR index of 0.77. Biofilm formation at different temperatures indicated significantly higher biofilm formation at 37 °C and 25 °C compared with 4 °C. Frequent monitoring of seafood for Vibrio species and their antibiotic, molecular and biofilm characteristics is essential to improve seafood safety. Copyright © 2018 Elsevier B.V. All rights reserved.

Homeotic genes and the arthropod head: Expression patterns of the labial, proboscipedia, and Deformed genes in crustaceans and insects

PubMed Central

Abzhanov, Arhat; Kaufman, Thomas C.

1999-01-01

cDNA fragments of the homologues of the Drosophila head homeotic genes labial (lab), proboscipedia (pb), and Deformed (Dfd) have been isolated from the crustacean Porcellio scaber. Because the accumulation domains of the head homeotic complex (Hox) genes had not been previously reported for crustaceans, we studied the expression patterns of these genes in P. scaber embryos by using in situ hybridization. The P. scaber lab homologue is expressed in the developing second antennal segment and its appendages. This expression domain in crustaceans and in the homologous intercalary segment of insects suggests that the lab gene specified this metamere in the last common ancestor of these two groups. The expression domain of the P. scaber pb gene is in the posterior part of the second antennal segment. This domain, in contrast to that in insects, is colinear with the domains of other head genes in P. scaber, and it differs from the insect pb gene expression domain in the posterior mouthparts, suggesting that the insect and crustacean patterns evolved independently from a broader ancestral domain similar to that found in modern chelicerates. P. scaber Dfd is expressed in the mandibular segment and paragnaths (a pair of ventral mouthpart structures associated with the stomodeum) and differs from insects, where expression is in the mandibular and maxillary segments. Thus, like pb, Dfd shows a divergent Hox gene deployment. We conclude that homologous structures of the mandibulate head display striking differences in their underlying developmental programs related to Hox gene expression. PMID:10468590

Measurement of Neuropeptides in Crustacean Hemolymph via MALDI Mass Spectrometry

PubMed Central

Chen, Ruibing; Ma, Mingming; Hui, Limei; Zhang, Jiang; Li, Lingjun

2009-01-01

Neuropeptides are often released into circulatory fluid (hemolymph) to act as circulating hormones and regulate many physiological processes. However, the detection of these low-level peptide hormones in circulation is often complicated by high salt interference and rapid degradation of proteins and peptides in crude hemolymph extracts. In this study, we systematically evaluated three different neuropeptide extraction protocols and developed a simple and effective hemolymph preparation method suitable for MALDI MS profiling of neuropeptides by combining acid-induced abundant protein precipitation/depletion, ultrafiltration, and C18 micro-column desalting. In hemolymph samples collected from crab Cancer borealis several secreted neuropeptides have been detected, including members from at least five neuropeptide families, such as RFamide, allatostatin, orcokinin, tachykinin-related peptide (TRP), and crustacean cardioactive peptide (CCAP). Furthermore, two TRPs were detected in the hemolymph collected from food-deprived animals, suggesting the potential role of these neuropeptides in feeding regulation. In addition, a novel peptide with a Lys-Phe-amide C-terminus was identified and de novo sequenced directly from the Cancer borealis hemolymph sample. To better characterize the hemolymph peptidome, we also identified several abundant peptide signals in C. borealis hemolymph that were assigned to protein degradation products. Collectively, our study describes a simple and effective sample preparation method for neuropeptide analysis directly from crude crustacean hemolymph. Numerous endogenous neuropeptides were detected including both known ones and new peptides whose functions remain to be characterized. PMID:19185513

Metabolic rates of benthic deep-sea decapod crustaceans decline with increasing depth primarily due to the decline in temperature

NASA Astrophysics Data System (ADS)

Childress, J. J.; Cowles, D. L.; Favuzzi, J. A.; Mickel, T. J.

1990-06-01

The oxygen consumption rates of 11 species of benthic deep-sea decapod crustaceans were measured at a variety of temperatures to test the hypothesis that the metabolic rates of benthic crustaceans decline with increasing depth of occurrence only to the extent explained by the decline in temperature with depth. The species were captured at depths between 150 and 2000m off Southern California using an epibenthic beam trawl equipped with a thermally protecting cod-end to bring the animals to the surface uncontaminated by sediment and at the depth temperature. The data, combined with those for six species of shallower-living crustaceans from California waters, showed a significant decline in oxygen consumption rate with increased species' depths of occurrence, when the measurements were made at temperatures appropriate to each species' depth range. There was no significant relation between wet weight and depth of occurrence in these species. When the data were adjusted to 10°C using a moderate temperature effect factor (corresponding to Q10 values of 2-2.3 depending on the species and temperature range), the significant relationship between oxygen consumption rate and depth was lost, indicating that the observed decline with depth was due to the decline in temperature with depth. When the relationship between metabolic rate and depth of occurrence for the most active (carideans and penaeid) species were compared (ANCOVA) with that for the rest of the species, the active species had significantly higher rates. By combining this data set with data from the literature for a wide variety of shallow-living benthic decapod crustaceans, it was possible to create a data set of 35 species in which the effects of temperature, minimum depth of occurrence and body mass could be separated by multiple linear regression. This demonstrated highly significant effects of size and temperature, but no significant effect of depth for the entire data set and for the data set excluding

Scale Dependence of the Mechanical Properties and Microstructure of Crustaceans Thin Films as Biomimetic Materials

NASA Astrophysics Data System (ADS)

Verma, Devendra; Qu, Tao; Tomar, Vikas

2015-04-01

The exoskeletons of crustacean species in the form of thin films have been investigated by several researchers to better understand the role played by the exoskeletal structure in affecting the functioning of species such as shrimps, crabs, and lobsters. These species exhibit similar designs in their exoskeleton microstructure, such as a Bouligand pattern (twisted plywood structure), layers of different thickness across cross section, change in mineral content through the layers, etc. Different parts of crustaceans exhibit a significant variation in mechanical properties based on the variation in the above-mentioned parameters. This change in mechanical properties has been analyzed by using imaging techniques such as scanning electron microscopy and energy-dispersive x-ray spectroscopy, and by using mechanical characterization techniques such as nanoindentation and atomic force microscopy. In this article, the design principles of these biological composites are discussed based on two shrimp species: Rimicaris exoculata and Pandalus platyceros.

Hiding opaque eyes in transparent organisms: a potential role for larval eyeshine in stomatopod crustaceans.

PubMed

Feller, K D; Cronin, T W

2014-09-15

Opaque screening pigments are a fundamental requisite for preserving resolution in image-forming eyes. Possession of any type of image-forming eye in a transparent, pelagic animal will thus undermine the ability of that animal to be invisible in the water column. Transparent, pelagic animals must therefore deal with the trade-off between the ability to see and the ability of other animals to see them. Stomatopod larvae, like many transparent crustaceans, possess specialized optics in their compound eyes that minimize the volume of the opaque retina. Though the volumes of these retinas are reduced, their opacity remains conspicuous to an observer. The light reflected from structures overlying the retinas of stomatopod crustacean larval eyes, referred to here as eyeshine, is hypothesized to further reduce the visibility of opaque retinas. Blue or green wavelengths of light are most strongly reflected in stomatopod larval eyeshine, suggesting a putative spectral matching to the light environment against which the larval eyes are viewed. We tested the efficacy of stomatopod crustacean larval eyeshine as an ocular camouflaging mechanism by photographing larvae in their natural light environment and analysing the contrast of eyes with the background light. To test for spectral matching between stomatopod larval eyeshine and the background light environment, we characterized the spectrum of eyeshine and calculated its performance using radiometric measurements collected at the time of each photographic series. These results are the first to demonstrate an operative mirror camouflage matched in both spectrum and radiance to the pelagic background light environment. © 2014. Published by The Company of Biologists Ltd.

Crustacean hyperglycemic and vitellogenesis-inhibiting hormones in the lobster Homarus gammarus.

PubMed

Ollivaux, Céline; Vinh, Joëlle; Soyez, Daniel; Toullec, Jean-Yves

2006-05-01

Crustacean hyperglycemic hormone (CHH) and vitellogenesis-inhibiting hormone (VIH), produced by the X organ-sinus gland neurosecretory complex, belong to a peptide group referred to as the CHH family, which is widely distributed in arthropods. In this study, genetic variants and post-translationally modified isoforms of CHH and VIH were characterized in the European lobster Homarus gammarus. With the use of RP-HPLC and ELISA with specific antibodies that discriminate between stereoisomers of CHH and VIH, two groups of CHH-immunoreactive peaks were characterized from HPLC fractions of sinus gland extract (CHH A and CHH B); each group contained two variants (CHH and D-Phe3CHH). In the same way, two VIH-immunoreactive peaks (VIH and D-Trp4VIH) were demonstrated in HPLC fractions from sinus gland extract. The masses of these different neuropeptides were determined by FT-ICR MS: CHH A and CHH B spectra exhibited monoisotopic ions at 8557.05 Da and 8527.04 Da, respectively, and both VIH isomers displayed an m/z value of 9129.19 Da. Two full-length cDNAs encoding preprohomones of CHH A and CHH B and only one cDNA for VIH precursor were cloned and sequenced from X organ RNA. Comparison of CHH sequences between European lobster and other Astacoidea suggests that the most hydrophobic form appeared first during crustacean evolution.

MYSID CRUSTACEANS AS POTENTIAL TEST ORGANISMS FOR THE EVALUATION OF ENVIRONMENTAL ENDOCRINE DISRUPTORS: A REVIEW

EPA Science Inventory

Verslycke, Tim A., Nancy Fockedey, Charles L. McKenney, Jr., Stephen D. Roast, Malcolm B. Jones, Jan Mees and Colin R. Janssen. 2004. Mysid Crustaceans as Potential Test Organisms for the Evaluation of Environmental Endocrine Disruption: A Review. Environ. Toxicol. Chem. 23(5):12...

Muscle water control in crustaceans and fishes as a function of habitat, osmoregulatory capacity, and degree of euryhalinity.

PubMed

Freire, Carolina A; Amado, Enelise M; Souza, Luciana R; Veiga, Marcos P T; Vitule, Jean R S; Souza, Marta M; Prodocimo, Viviane

2008-04-01

This study aimed at detecting possible patterns in the relationship between Anisosmotic Extracellular Regulation (AER) and Isosmotic Intracellular Regulation (IIR) in crustaceans and teleost fish from different habitats and evolutionary histories in fresh water (FW), thus different osmoregulatory capabilities, and degrees of euryhalinity. Crustaceans used were the hololimnetic FW Aegla schmitti, and Macrobrachium potiuna, the diadromous FW Macrobrachium acanthurus, the estuarine Palaemon pandaliformis and the marine Hepatus pudibundus; fishes used were the FW Corydoras ehrhardti, Mimagoniates microlepis, and Geophagus brasiliensis, and the marine-estuarine Diapterus auratus. The capacity for IIR was assessed in vitro following wet weight changes of isolated muscle slices incubated in anisosmotic saline (~50% change). M. potiuna was the crustacean with the highest capacity for IIR; the euryhaline perciforms G. brasiliensis and D. auratus displayed total capacity for IIR. It is proposed that a high capacity for IIR is required for invading a new habitat, but that it is later lost after a long time of evolution in a stable habitat, such as in the FW anomuran crab A. schmitti, and the Ostariophysian fishes C. ehrhardti and M. microlepis. More recent FW invaders such as the palaemonid shrimps (M. potiuna and M. acanthurus) and the cichlid G. brasiliensis are euryhaline and still display a high capacity for IIR.

House dust mite (Der p 10) and crustacean allergic patients may react to food containing Yellow mealworm proteins.

PubMed

Verhoeckx, Kitty C M; van Broekhoven, Sarah; den Hartog-Jager, Constance F; Gaspari, Marco; de Jong, Govardus A H; Wichers, Harry J; van Hoffen, Els; Houben, Geert F; Knulst, André C

2014-03-01

Due to the imminent growth of the world population, shortage of protein sources for human consumption will arise in the near future. Alternative and sustainable protein sources (e.g. insects) are being explored for the production of food and feed. In this project, the safety of Yellow mealworms (Tenebrio molitor L.) for human consumption was tested using approaches as advised by the European Food Safety Authority for allergenicity risk assessment. Different Yellow mealworm protein fractions were prepared, characterised, and tested for cross-reactivity using sera from patients with an inhalation or food allergy to biologically related species (House dust mite (HDM) and crustaceans) by immunoblotting and basophil activation. Furthermore, the stability was investigated using an in vitro pepsin digestion test. IgE from HDM- and crustacean allergic patients cross-reacted with Yellow mealworm proteins. This cross-reactivity was functional, as shown by the induction of basophil activation. The major cross-reactive proteins were identified as tropomyosin and arginine kinase, which are well known allergens in arthropods. These proteins were moderately stable in the pepsin stability test. Based on these cross-reactivity studies, there is a realistic possibility that HDM- and crustacean allergic patients may react to food containing Yellow mealworm proteins. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of Mg2+ on Ca2+ release from sarcoplasmic reticulum of skeletal muscle fibres from yabby (crustacean) and rat.

PubMed

Launikonis, B S; Stephenson, D G

2000-07-15

1. The role of myoplasmic [Mg2+] on Ca2+ release from the sarcoplasmic reticulum (SR) was examined in the two major types of crustacean muscle fibres, the tonic, long sarcomere fibres and the phasic, short sarcomere fibres of the fresh water decapod crustacean Cherax destructor (yabby) and in the fast-twitch rat muscle fibres using the mechanically skinned muscle fibre preparation. 2. A robust Ca2+-induced Ca2+-release (CICR) mechanism was present in both long and short sarcomere fibres and 1 mM Mg2+ exerted a strong inhibitory action on the SR Ca2+ release in both fibre types. 3. The SR displayed different properties with respect to Ca2+ loading in the long and the short sarcomere fibres and marked functional differences were identified with respect to Mg2+ inhibition between the two crustacean fibre types. Thus, in long sarcomere fibres, the submaximally loaded SR was able to release Ca2+ when [Mg2+] was lowered from 1 to 0.01 mM in the presence of 8 mM ATPtotal and in the virtual absence of Ca2+ (< 5 nM) even when the CICR was suppressed. In contrast, negligible Ca2+ was released from the submaximally loaded SR of short sarcomere yabby fibres when [Mg2+] was lowered from 1 to 0.01 mM under the same conditions as for the long sarcomere fibres. Nevertheless, the rate of SR Ca2+ release in short sarcomere fibres increased markedly when [Mg2+] was lowered in the presence of [Ca2+] approaching the normal resting levels (50-100 nM). 4. Rat fibres were able to release SR Ca2+ at a faster rate than the long sarcomere yabby fibres when [Mg2+] was lowered from 1 to 0. 01 mM in the virtual absence of Ca2+ but, unlike with yabby fibres, the net rate of Ca2+ release was actually increased for conditions that were considerably less favourable to CICR. 5. In summary, it is concluded that crustacean skeletal muscles have more that one functional type of Ca2+-release channels, that these channels display properties that are intermediate between those of mammalian skeletal and

Effect of meal size and body size on specific dynamic action and gastric processing in decapod crustaceans.

PubMed

McGaw, Iain J; Curtis, Daniel L

2013-11-01

Meal size and animal size are important factors affecting the characteristics of the specific dynamic action (SDA) response across a variety of taxa. The effects of these two variables on the SDA of decapod crustaceans are based on just a couple of articles, and are not wholly consistent with the responses reported for other aquatic ectotherms. Therefore, the effects of meal size and animal size on the characteristics of SDA response were investigated in a variety of decapod crustaceans from different families. A 6 fold increase in meal size (0.5%-3% body mass) resulted a pronounced increase in the duration of increased oxygen consumption, resulting in an increase in the SDA of Callinectes sapidus, Cancer gracilis, Hemigrapsus nudus, Homarus americanus, Pugettia producta and Procambarus clarkii. Unlike many other aquatic ectotherms a substantial increase between meal sizes was required, with meal size close to their upper feeding limit (3% body mass), before changes were evident. In many organisms increases in both duration and scope contribute to the overall SDA, here changes in scope as a function of meal size were weak, suggesting that a similar amount of energy is required to upregulate gastric processes, regardless of meal size. The SDA characteristics were less likely to be influenced by the size of the animal, and there was no difference in the SDA (kJ) as a function of size in H. americanus or Cancer irroratus when analysed as mass specific values. In several fish species characteristics of the SDA response are more closely related to the transit times of food, rather than the size of a meal. To determine if a similar trend occurred in crustaceans, the transit rates of different sized meals were followed through the digestive system using a fluoroscope. Although there was a trend towards larger meals taking longer to pass through the gut, this was only statistically significant for P. clarkii. There were some changes in transit times as a function of animal

Effects of hydrolyzed Chlorella vulgaris by malted barley on the immunomodulatory response in ICR mice and in Molt-4 cells.

PubMed

Kim, Na-Hyung; Kim, Kyu-Yeob; Jeong, Hyun-Ja; Kim, Hyung-Min; Hong, Seung-Heon; Um, Jae-Young

2010-07-01

Chlorella vulgaris is a unicellular and microscopic algae that is currently used in a variety of forms of tablets, capsules and liquid as a biological response modifier. The aim of this study was to investigate the effects of hydrolyzed Chlorella vulgaris by malted barley for its potential reduction of the immobility time in ICR mice and on the cytokine regulation in human T cell line, Molt-4. After a forced swimming test, the changes in aspects of blood biochemical parameters due to the administration of hydrolyzed Chlorella vulgaris by malted barley were examined. The effect of hydrolyzed Chlorella vulgaris by the malted barley-treated group for 14 days on the immobility time was significantly reduced in comparison with that of the control group (P < 0.01). The plasma level of blood urea nitrogen was significantly decreased in hydrolyzed Chlorella vulgaris by malted barley-treated group compared with the control group (P < 0.05). In addition, hydrolyzed Chlorella vulgaris by malted barley increased interferon-gamma and interlukin-2 levels in Molt-4 cells. These results indicate that hydrolyzed Chlorella vulgaris by malted barley is useful for immune function improvements, enhanced physical stamina, and as a candidate for an anti-fatigue or antidepressant agent.

A Novel Chitin Binding Crayfish Molar Tooth Protein with Elasticity Properties

PubMed Central

Tynyakov, Jenny; Bentov, Shmuel; Abehsera, Shai; Khalaila, Isam; Manor, Rivka; Katzir Abilevich, Lihie; Weil, Simy; Aflalo, Eliahu D.; Sagi, Amir

2015-01-01

The molar tooth of the crayfish Cherax quadricarinatus is part of the mandible, and is covered by a layer of apatite (calcium phosphate). This tooth sheds and is regenerated during each molting cycle together with the rest of the exoskeleton. We discovered that molar calcification occurs at the pre-molt stage, unlike calcification of the rest of the new exoskeleton. We further identified a novel molar protein from C. quadricarinatus and cloned its transcript from the molar-forming epithelium. We termed this protein Cq-M13. The temporal level of transcription of Cq-M13 in an NGS library of molar-forming epithelium at different molt stages coincides with the assembly and mineralization pattern of the molar tooth. The predicted protein was found to be related to the pro-resilin family of cuticular proteins. Functionally, in vivo silencing of the transcript caused molt cycle delay and a recombinant version of the protein was found to bind chitin and exhibited elastic properties. PMID:26010981

DNA sequence database as a tool to identify decapod crustaceans on the São Paulo coastline.

PubMed

Mantelatto, Fernando L; Terossi, Mariana; Negri, Mariana; Buranelli, Raquel C; Robles, Rafael; Magalhães, Tatiana; Tamburus, Ana Francisca; Rossi, Natália; Miyazaki, Mayara J

2017-09-05

DNA barcoding has emerged as an efficient tool for taxonomy and other biodiversity fields. The vast and speciose group of decapod crustaceans is not an exception in the current scenario and comparing short DNA fragments has enabled researchers to overcome some taxonomic impediments to help broadening knowledge on the diversity of this group of crustaceans. Brazil is considered as an important area in terms of global marine biodiversity and some regions stand out in terms of decapod fauna, such as the São Paulo coastline. Thus, the aim of this study is to obtain sequences of the mitochondrial markers (COI and 16S) for decapod crustaceans distributed at the São Paulo coastline and to test the accuracy of these markers for species identification from this region by comparing our sequences to those already present in the GenBank database. We sampled along almost the 300 km of the São Paulo coastline from estuaries to offshore islands during the development of a multidisciplinary research project that took place for 5 years. All the species were processed to obtain the DNA sequences. The diversity of the decapod fauna on the São Paulo coastline comprises at least 404 species. We were able to collect 256 of those species and sequence of at least one of the target genes from 221. By testing the accuracy of these two DNA markers as a tool for identification, we were able to check our own identifications, including new records in GenBank, spot potential mistakes in GenBank, and detect potential new species.

Hematodinium spp. infections in wild and cultured populations of marine crustaceans along the coast of China.

PubMed

Wang, Jin-Feng; Li, Meng; Xiao, Jie; Xu, Wen-Jun; Li, Cai-Wen

2017-05-11

The parasitic dinoflagellate Hematodinium spp. infects a broad range of marine crustaceans. Its epidemics have impacted wild populations of various commercial fishery species around the world and the sustainability of mariculture in China. To study the epidemiology of Hematodinium spp. in marine crustaceans along the coast of China, we conducted a broad survey of wild and cultured stocks of major crustacean species in 2013 to 2015. Hematodinium sp. infections were identified in wild stocks of Portunus trituberculatus from Huludao, Laizhou, Qingdao, Yangtze River Estuary and Zhoushan, and Scylla paramamosain from Shantou; and cultured stocks of Portunus trituberculatus and Penaeus monodon from a polyculture pond in Qingdao. In the polyculture pond, Hematodinium sp. infections were observed in Portunus trituberculatus from June until October, with peak prevalence (up to 90%) observed in late July to early August. Furthermore, Hematodinium sp. infection was identified for the first time in the giant tiger prawn Penaeus monodon in the polyculture system during the disease outbreak. Phylogenetic analysis indicated that the Hematodinium isolate infecting Penaeus monodon was identical to the isolate infecting the co-cultured Portunus trituberculatus, and it was grouped into H. perezi genotype II together with the other isolates reported in China. The Hematodinium sp. isolated from Portunus trituberculatus appeared to have similar life stages as the H. perezi genotype III isolated from the American blue crab Callinectes sapidus. Our study indicates that outbreaks of Hematodinium disease can be a significant threat to the widely used polyculture system for decapods in China that may be particularly vulnerable to such generalist pathogens.

DETERMINATION OF LETHAL DISSOLVED OXYGEN LEVELS FOR SELECTED MARINE AND ESTUARINE FISHES, CRUSTACEANS AND A BIVALVE

EPA Science Inventory

The objective of this study was to provide a database of the incipient lethal concentrations for reduced dissolved oxygen (DO) for selected marine and estuarine species including 12 species of fish, 9 crustaceans, and 1 bivalve. All species occur in the Virginian Province, USA, w...

USE OF OYSTER HABITAT BY REEF-RESIDENT FISHES AND DECAPOD CRUSTACEANS IN THE CALOOSAHATCHEE ESTUARY, FLORIDA

EPA Science Inventory

Habitat suitability of oyster reefs for fishes and decapod crustaceans was examined monthly at three sites in the lower Caloosahatchee Estuary. At each site, 1-m2 lift nets containing approximately 5 liters (volume displacement) of oyster clumps were deployed for a period of two ...

Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic). Blue Crab

DTIC Science & Technology

1989-03-01

size only by Music 1979). molting (Hay 1905). Zoeal development depends on salinity and temperature, Growth and maturation proceed but development time...substrates. the effects depends on the toxicant, concentration, time exposed, salinity , tidal cycle, age and molt phase of Other Environmental Factors...Temperature .......................................................... 11 Salinity ............................................................. I11

The origin of crustaceans: new evidence from the Early Cambrian of China.

PubMed Central

Chen, J. Y.; Vannier, J.; Huang, D. Y.

2001-01-01

One of the smallest arthropods recently discovered in the Early Cambrian Maotianshan Shale Lagerstätte is described. Ercaia gen. nov. has an untagmatized trunk bearing serially repeated biramous appendages (long and segmented endopods and flap-like exopods), a head with an acron bearing stalked lateral eyes and a sclerite and two pairs of antennae. The position of this 520 million-year-old tiny arthropod within the Crustacea is supported by several anatomical features: (i) a head with five pairs of appendages including two pairs of antennae, (ii) highly specialized antennae (large setose fans with a possible function in feeding), and (iii) specialized last trunk appendages (segmented pediform structures fringed with setae). The segmentation pattern of Ercaia (5 head and 13 trunk) is close to that of Maxillopoda but lacks the trunk tagmosis of modern representatives of the group. Ercaia is interpreted as a possible derivative of the stem group Crustacea. Ercaia is likely to have occupied an ecological niche similar to those of some Recent meiobenthic organisms (e.g. copepods living in association with sediment). This new fossil evidence supports the remote ancestry of crustaceans well before the Late Cambrian and shows, along with other fossil data (mainly Early Cambrian in China), that a variety of body plans already coexisted among the primitive crustacean stock. PMID:11674864

Insect Protein as a partial Replacement of Fishmeal in the Diets of Juvenile Fish and Crustaceans

USDA-ARS?s Scientific Manuscript database

This chapter represents a review of the published literature to determine if insect protein is an important supplement to - or even a replacement for - fishmeal in diets for juvenile fish and crustaceans. Fishmeal is becoming a finite resource. This chapter highlights areas of opportunity for produc...

Insect protein as a partial replacement of fishmeal in the diets of juvenile fish and crustaceans

USDA-ARS?s Scientific Manuscript database

This chapter represents a review of the published literature to determine if insect protein is an important supplement to - or even a replacement for - fishmeal in diets for juvenile fish and crustaceans. Fishmeal is becoming a finite resource. This chapter highlights areas of opportunity for produc...

Insect protein as a partical replacement of fishmeal in the diets of juvenile fish and crustaceans

USDA-ARS?s Scientific Manuscript database

This chapter represents a review of the published literature to determine if insect protein is an important supplement to - or even a replacement for - fishmeal in diets for juvenile fish and crustaceans. Fishmeal is becoming a finite resource. This chapter highlights areas of opportunity for prod...

Recent progress toward the identification of anti-viral immune mechanisms in decapod crustaceans.

PubMed

Hauton, Chris

2017-07-01

The sustainable intensification of crustacean aquaculture, which is dominated by the farming of penaeid shrimp species, continues to be beset by viral disease outbreaks. Despite this, reports exist of differential susceptibility to viral infection between different shrimp species and populations, and between shrimp and other decapod crustaceans. These reports have, in part, provided the motivation to identify key mechanisms of antiviral resistance, or refractivity, in commercially-important species. Within the last decade these studies have created significant advances in our understanding of host virus interactions in decapod models. However, at the same time, the complexity of host virus interactions has presented significant challenges for interpretation of anti-viral immune responses. In this short review, recent progress in our understanding of the complexity of host virus interactions are considered, and challenges to the unequivocal identification of anti-viral immunity are highlighted. Special consideration is given to the advances in understanding being created by the use of RNA interference approaches. Based on the 'state of the art', it is concluded that the identification of effective intervention strategies for application at farm scale currently presents an unrealistic target for the aquaculture industry. Future technical developments necessary to support continued progress are also considered. Copyright © 2017 Elsevier Inc. All rights reserved.

Reproduction in the freshwater crustacean Asellus aquaticus along a gradient of radionuclide contamination at Chernobyl.

PubMed

Fuller, Neil; Ford, Alex T; Nagorskaya, Liubov L; Gudkov, Dmitri I; Smith, Jim T

2018-07-01

Nuclear accidents such as Chernobyl and Fukushima have led to contamination of the environment that will persist for many years. The consequences of chronic low-dose radiation exposure for non-human organisms inhabiting contaminated environments remain unclear. In radioecology, crustaceans are important model organisms for the development of environmental radioprotection. Previous laboratory studies have demonstrated deleterious effects of radiation exposure on crustacean reproduction. However, no studies have documented the effects of chronic radiation exposure on the reproduction of natural crustacean populations. Based on data from laboratory exposures, we hypothesised that populations of the freshwater isopod Asellus aquaticus exposed to radiation for thirty years at Chernobyl would display reduced reproductive output and altered timing of reproduction. To test this hypothesis, A. aquaticus was collected from six lakes at Chernobyl over two years with total dose rates ranging from 0.06-27.1μGy/h. No significant differences in the fecundity, mass of broods or proportion of reproducing female A. aquaticus were recorded. Significant differences in the body mass of gravid females were recorded suggesting different timings of reproduction, however this was not related to radiation contamination. No significant effect of a range of environmental parameters on A. aquaticus reproduction was recorded. Our data suggests current dose rates at Chernobyl are not causing discernible effects on the reproductive output of A. aquaticus. This study is the first to assess the effects of chronic low-dose radiation exposure on the reproductive output of an aquatic invertebrate at Chernobyl. These findings are consistent with proposed radiological protection benchmarks for the maintenance of wildlife populations and will assist in management of environments impacted by radiation. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Redefining metamorphosis in spiny lobsters: molecular analysis of the phyllosoma to puerulus transition in Sagmariasus verreauxi

PubMed Central

Ventura, Tomer; Fitzgibbon, Quinn P.; Battaglene, Stephen C.; Elizur, Abigail

2015-01-01

The molecular understanding of crustacean metamorphosis is hindered by small sized individuals and inability to accurately define molt stages. We used the spiny lobster Sagmariasus verreauxi where the large, transparent larvae enable accurate tracing of the transition from a leaf-shaped phyllosoma to an intermediate larval-juvenile phase (puerulus). Transcriptomic analysis of larvae at well-defined stages prior to, during, and following this transition show that the phyllosoma-puerulus metamorphic transition is accompanied by vast transcriptomic changes exceeding 25% of the transcriptome. Notably, genes previously identified as regulating metamorphosis in other crustaceans do not fluctuate during this transition but in the later, morphologically-subtle puerulus-juvenile transition, indicating that the dramatic phyllosoma-puerulus morphological shift relies on a different, yet to be identified metamorphic mechanism. We examined the change in expression of domains and gene families, with focus on several key genes. Our research implies that the separation in molecular triggering systems between the phyllosoma-puerulus and puerulus-juvenile transitions might have enabled the extension of the oceanic phase in spiny lobsters. Study of similar transitions, where metamorphosis is uncoupled from the transition into the benthic juvenile form, in other commercially important crustacean groups might show common features to point on the evolutionary advantage of this two staged regulation. PMID:26311524

Redefining metamorphosis in spiny lobsters: molecular analysis of the phyllosoma to puerulus transition in Sagmariasus verreauxi.

PubMed

Ventura, Tomer; Fitzgibbon, Quinn P; Battaglene, Stephen C; Elizur, Abigail

2015-08-27

The molecular understanding of crustacean metamorphosis is hindered by small sized individuals and inability to accurately define molt stages. We used the spiny lobster Sagmariasus verreauxi where the large, transparent larvae enable accurate tracing of the transition from a leaf-shaped phyllosoma to an intermediate larval-juvenile phase (puerulus). Transcriptomic analysis of larvae at well-defined stages prior to, during, and following this transition show that the phyllosoma-puerulus metamorphic transition is accompanied by vast transcriptomic changes exceeding 25% of the transcriptome. Notably, genes previously identified as regulating metamorphosis in other crustaceans do not fluctuate during this transition but in the later, morphologically-subtle puerulus-juvenile transition, indicating that the dramatic phyllosoma-puerulus morphological shift relies on a different, yet to be identified metamorphic mechanism. We examined the change in expression of domains and gene families, with focus on several key genes. Our research implies that the separation in molecular triggering systems between the phyllosoma-puerulus and puerulus-juvenile transitions might have enabled the extension of the oceanic phase in spiny lobsters. Study of similar transitions, where metamorphosis is uncoupled from the transition into the benthic juvenile form, in other commercially important crustacean groups might show common features to point on the evolutionary advantage of this two staged regulation.

A Comparative study on the nonspecific immunity of juvenile Litopenaeus vannamei ever inhabiting freshwater and seawater

NASA Astrophysics Data System (ADS)

Jia, Xuying; Ding, Sen; Wang, Fang; Dong, Shuanglin

2014-06-01

A study on the nonspecific immunity of Litopenaeus vannamei ever inhabiting freshwater and seawater was carried out at different molt stages by comparing their total hemocyte count (THC) and respiratory burst (RB) and activity of phenol oxidase (PO), nitric oxide synthase (NOS) and lysozyme (LY). Two-way ANOVA showed that salinity and molt stage independently affected THC and RB and the activity of PO, NOS and LY of juvenile L. vannamei significantly ( P < 0.05). The THC and RB and the activity of NOS gradually increased from the post-molt stages (A and B) to the pre-molt stages (D0-D3), which were common in shrimps inhabiting freshwater and seawater. The activity of PO peaked at the inter-molt stage (C), and touched the lowest at the post-molt stage in freshwater and pre-molt stage in seawater. The activity of LY was stable over the molt cycle. The RB and the activity of PO, NOS and LY of juvenile L. vannamei were significantly lower in freshwater than in seawater; whereas THC was significantly higher in freshwater than in seawater ( P < 0.05). It was concluded that the post-molt stage (especially stage A) was critical to shrimp culture, which should be intensively attended when L. vannamei was cultured in freshwater.

Genome-wide analyses of the bHLH superfamily in crustaceans: reappraisal of higher-order groupings and evidence for lineage-specific duplications

PubMed Central

2018-01-01

The basic helix-loop-helix (bHLH) proteins represent a key group of transcription factors implicated in numerous eukaryotic developmental and signal transduction processes. Characterization of bHLHs from model species such as humans, fruit flies, nematodes and plants have yielded important information on their functions and evolutionary origin. However, relatively little is known about bHLHs in non-model organisms despite the availability of a vast number of high-throughput sequencing datasets, enabling previously intractable genome-wide and cross-species analyses to be now performed. We extensively searched for bHLHs in 126 crustacean species represented across major Crustacea taxa and identified 3777 putative bHLH orthologues. We have also included seven whole-genome datasets representative of major arthropod lineages to obtain a more accurate prediction of the full bHLH gene complement. With focus on important food crop species from Decapoda, we further defined higher-order groupings and have successfully recapitulated previous observations in other animals. Importantly, we also observed evidence for lineage-specific bHLH expansions in two basal crustaceans (branchiopod and copepod), suggesting a mode of evolution through gene duplication as an adaptation to changing environments. In-depth analysis on bHLH-PAS members confirms the phenomenon coined as ‘modular evolution’ (independently evolved domains) typically seen in multidomain proteins. With the amphipod Parhyale hawaiensis as the exception, our analyses have focused on crustacean transcriptome datasets. Hence, there is a clear requirement for future analyses on whole-genome sequences to overcome potential limitations associated with transcriptome mining. Nonetheless, the present work will serve as a key resource for future mechanistic and biochemical studies on bHLHs in economically important crustacean food crop species. PMID:29657824

The genome of the crustacean Parhyale hawaiensis, a model for animal development, regeneration, immunity and lignocellulose digestion.

PubMed

Kao, Damian; Lai, Alvina G; Stamataki, Evangelia; Rosic, Silvana; Konstantinides, Nikolaos; Jarvis, Erin; Di Donfrancesco, Alessia; Pouchkina-Stancheva, Natalia; Sémon, Marie; Grillo, Marco; Bruce, Heather; Kumar, Suyash; Siwanowicz, Igor; Le, Andy; Lemire, Andrew; Eisen, Michael B; Extavour, Cassandra; Browne, William E; Wolff, Carsten; Averof, Michalis; Patel, Nipam H; Sarkies, Peter; Pavlopoulos, Anastasios; Aboobaker, Aziz

2016-11-16

The amphipod crustacean Parhyale hawaiensis is a blossoming model system for studies of developmental mechanisms and more recently regeneration. We have sequenced the genome allowing annotation of all key signaling pathways, transcription factors, and non-coding RNAs that will enhance ongoing functional studies. Parhyale is a member of the Malacostraca clade, which includes crustacean food crop species. We analysed the immunity related genes of Parhyale as an important comparative system for these species, where immunity related aquaculture problems have increased as farming has intensified. We also find that Parhyale and other species within Multicrustacea contain the enzyme sets necessary to perform lignocellulose digestion ('wood eating'), suggesting this ability may predate the diversification of this lineage. Our data provide an essential resource for further development of Parhyale as an experimental model. The first malacostracan genome will underpin ongoing comparative work in food crop species and research investigating lignocellulose as an energy source.

Long-term responses of sandy beach crustaceans to the effects of coastal armouring after the 2010 Maule earthquake in South Central Chile

NASA Astrophysics Data System (ADS)

Rodil, Iván F.; Jaramillo, Eduardo; Acuña, Emilio; Manzano, Mario; Velasquez, Carlos

2016-02-01

Earthquakes and tsunamis are large physical disturbances frequently striking the coast of Chile with dramatic effects on intertidal habitats. Armouring structures built as societal responses to beach erosion and shoreline retreat are also responsible of coastal squeeze and habitat loss. The ecological implications of interactions between coastal armouring and earthquakes have recently started to be studied for beach ecosystems. How long interactive impacts persist is still unclear because monitoring after disturbance generally extends for a few months. During five years after the Maule earthquake (South Central Chile, February 27th 2010) we monitored the variability in population abundances of the most common crustacean inhabitants of different beach zones (i.e. upper, medium, and lower intertidal) at two armoured (one concrete seawall and one rocky revetment) and one unarmoured sites along the sandy beach of Llico. Beach morphology changed after the earthquake-mediated uplift, restoring upper- and mid-shore armoured levels that were rapidly colonized by typical crustacean species. However, post-earthquake increasing human activities affected the colonization process of sandy beach crustaceans in front of the seawall. Lower-shore crab Emerita analoga was the less affected by armouring structures, and it was the only crustacean species present at the three sites before and after the earthquake. This study shows that field sampling carried out promptly after major disturbances, and monitoring of the affected sites long after the disturbance is gone are effective approaches to increase the knowledge on the interactive effects of large-scale natural phenomena and artificial defences on beach ecology.

Evolution of body size, vision, and biodiversity of coral-associated organisms: evidence from fossil crustaceans in cold-water coral and tropical coral ecosystems.

PubMed

Klompmaker, Adiël A; Jakobsen, Sten L; Lauridsen, Bodil W

2016-06-16

Modern cold-water coral and tropical coral environments harbor a highly diverse and ecologically important macrofauna of crustaceans that face elevated extinction risks due to reef decline. The effect of environmental conditions acting on decapod crustaceans comparing these two habitats is poorly understood today and in deep time. Here, we compare the biodiversity, eye socket height as a proxy for eye size, and body size of decapods in fossil cold-water and tropical reefs that formed prior to human disturbance. We show that decapod biodiversity is higher in fossil tropical reefs from The Netherlands, Italy, and Spain compared to that of the exceptionally well-preserved Paleocene (Danian) cold-water reef/mound ecosystem from Faxe (Denmark), where decapod diversity is highest in a more heterogeneous, mixed bryozoan-coral habitat instead of in coral and bryozoan-dominated facies. The relatively low diversity at Faxe was not influenced substantially by the preceding Cretaceous/Paleogene extinction event that is not apparent in the standing diversity of decapods in our analyses, or by sampling, preservation, and/or a latitudinal diversity gradient. Instead, the lower availability of food and fewer hiding places for decapods may explain this low diversity. Furthermore, decapods from Faxe are larger than those from tropical waters for half of the comparisons, which may be caused by a lower number of predators, the delayed maturity, and the increased life span of crustaceans in deeper, colder waters. Finally, deep-water specimens of the benthic crab Caloxanthus from Faxe exhibit a larger eye socket size compared to congeneric specimens from tropical reefs, suggesting that dim light conditions favored the evolution of relatively large eyes. The results suggest a strong habitat control on the biodiversity of crustaceans in coral-associated environments and that the diversity difference between deep, cold-water reefs and tropical reefs evolved at least ~63 million years ago

Extinction, recolonization, and dispersal through time in a planktonic crustacean.

PubMed

Mergeay, Joachim; Vanoverbeke, Joost; Verschuren, Dirk; De Meester, Luc

2007-12-01

Dormant propagule banks are important reservoirs of biological and genetic diversity of local communities and populations and provide buffering mechanisms against extinction. Although dormant stages of various plant and animal species are known to remain viable for decades and even centuries, little is known about the effective influence of recolonization from such old sources on the genetic continuity of intermittent populations under natural conditions. Using recent and old dormant eggs recovered from a dated lake sediment core in Kenya, we traced the genetic composition of a local population of the planktonic crustacean Daphnia barbata through a sequence of extinction and recolonization events. This was combined with a phylogeographic and population-genetic survey of regional populations. Four successive populations, fully separated in time, inhabited Lake Naivasha from ca. 1330 to 1570 AD, from ca. 1610 to 1720 AD, from ca. 1840 to 1940 AD, and from 1995 to the present (2001 AD). Our results strongly indicate genetic continuity between the 1840-1940 and 1995-2001 populations, which are separated in time by at least 50 years, and close genetic relatedness of them both to the 1330-1580 population. A software tool (Colonize) was developed to find the most likely source population of the refounded 1995-2001 population and to test the number of colonists involved in the recolonization event. The results confirmed that the 1995-2001 population most probably developed out of a limited number of surviving local dormant eggs from the previous population, rather than out of individuals from regional (central and southern Kenya) or more distant (Ethiopia, Zimbabwe) populations that may have immigrated to Lake Naivasha through passive dispersal. These results emphasize the importance of prolonged dormancy for the natural long-term dynamics of crustacean zooplankton in fluctuating environments and suggest an important role of old local dormant egg banks in aquatic habitat

From the Palaeontological Collection of the Universalmuseum Joanneum - The Cenozoic Decapod Crustaceans (Crustacea: Malacostraca: Decapoda).

PubMed

Hyžný, Matúš; Gross, Martin

2016-01-01

Cenozoic decapod crustaceans housed in the collections of the Universalmuseum Joanneum (Graz, Austria) are reviewed. Previous descriptions, geographic and stratigraphic provenance and collection history are discussed. Altogether 72 specimens are figured, including five holotypes. Taxonomic affinity of previously unpublished material is addressed. Gebiacantha sp. from the middle Miocene of Wetzelsdorf is the first fossil record of the genus from the Paratethys.

An updated review on use of tomato pomace and crustacean processing waste to recover commercially vital carotenoids.

PubMed

Saini, Ramesh Kumar; Moon, So Hyun; Keum, Young-Soo

2018-06-01

Globally, the amount of food processing waste has become a major concern for environmental sustainability. The valorization of these waste materials can solve the problems of its disposal. Notably, the tomato pomace and crustacean processing waste presents enormous opportunities for the extraction of commercially vital carotenoids, lycopene, and astaxanthin, which have diverse applications in the food, feed, pharmaceuticals, and cosmetic industries. Moreover, such waste can generate surplus revenue which can significantly improve the economics of food production and processing. Considering these aspects, many reports have been published on the efficient use of tomato and crustacean processing waste to recover lycopene and astaxanthin. The current review provides up-to-date information available on the chemistry of lycopene and astaxanthin, their extraction methods that use environmentally friendly green solvents to minimize the impact of toxic chemical solvents on health and environment. Future research challenges in this context are also identified. Copyright © 2018 Elsevier Ltd. All rights reserved.

The genome of the crustacean Parhyale hawaiensis, a model for animal development, regeneration, immunity and lignocellulose digestion

PubMed Central

Kao, Damian; Lai, Alvina G; Stamataki, Evangelia; Rosic, Silvana; Konstantinides, Nikolaos; Jarvis, Erin; Di Donfrancesco, Alessia; Pouchkina-Stancheva, Natalia; Sémon, Marie; Grillo, Marco; Bruce, Heather; Kumar, Suyash; Siwanowicz, Igor; Le, Andy; Lemire, Andrew; Eisen, Michael B; Extavour, Cassandra; Browne, William E; Wolff, Carsten; Averof, Michalis; Patel, Nipam H; Sarkies, Peter; Pavlopoulos, Anastasios; Aboobaker, Aziz

2016-01-01

The amphipod crustacean Parhyale hawaiensis is a blossoming model system for studies of developmental mechanisms and more recently regeneration. We have sequenced the genome allowing annotation of all key signaling pathways, transcription factors, and non-coding RNAs that will enhance ongoing functional studies. Parhyale is a member of the Malacostraca clade, which includes crustacean food crop species. We analysed the immunity related genes of Parhyale as an important comparative system for these species, where immunity related aquaculture problems have increased as farming has intensified. We also find that Parhyale and other species within Multicrustacea contain the enzyme sets necessary to perform lignocellulose digestion ('wood eating'), suggesting this ability may predate the diversification of this lineage. Our data provide an essential resource for further development of Parhyale as an experimental model. The first malacostracan genome will underpin ongoing comparative work in food crop species and research investigating lignocellulose as an energy source. DOI: http://dx.doi.org/10.7554/eLife.20062.001 PMID:27849518

From cooperation to combat: adverse effect of thermal stress in a symbiotic coral-crustacean community.

PubMed

Stella, J S; Munday, P L; Walker, S P W; Pratchett, M S; Jones, G P

2014-04-01

Although mutualisms are ubiquitous in nature, our understanding of the potential impacts of climate change on these important ecological interactions is deficient. Here, we report on a thermal stress-related shift from cooperation to antagonism between members of a mutualistic coral-dwelling community. Increased mortality of coral-defending crustacean symbionts Trapezia cymodoce (coral crab) and Alpheus lottini (snapping shrimp) was observed in response to experimentally elevated temperatures and reduced coral-host (Pocillopora damicornis) condition. However, strong differential numerical effects occurred among crustaceans as a function of species and sex, with shrimp (75%), and female crabs (55%), exhibiting the fastest and greatest declines in numbers. These declines were due to forceful eviction from the coral-host by male crabs. Furthermore, surviving female crabs were impacted by a dramatic decline (85%) in egg production, which could have deleterious consequences for population sustainability. Our results suggest that elevated temperature switches the fundamental nature of this interaction from cooperation to competition, leading to asymmetrical effects on species and/or sexes. Our study illustrates the importance of evaluating not only individual responses to climate change, but also potentially fragile interactions within and among susceptible species.

Comparative toxicity of pyrethroid insecticides to two estuarine crustacean species, Americamysis bahia and Palaemonetes pugio.

PubMed

DeLorenzo, Marie E; Key, Peter B; Chung, Katy W; Sapozhnikova, Yelena; Fulton, Michael H

2014-10-01

Pyrethroid insecticides are widely used on agricultural crops, as well as for nurseries, golf courses, urban structural and landscaping sites, residential home and garden pest control, and mosquito abatement. Evaluation of sensitive marine and estuarine species is essential for the development of toxicity testing and risk-assessment protocols. Two estuarine crustacean species, Americamysis bahia (mysids) and Palaemonetes pugio (grass shrimp), were tested with the commonly used pyrethroid compounds, lambda-cyhalothrin, permethrin, cypermethrin, deltamethrin, and phenothrin. Sensitivities of adult and larval grass shrimp and 7-day-old mysids were compared using standard 96-h LC50 bioassay protocols. Adult and larval grass shrimp were more sensitive than the mysids to all the pyrethroids tested. Larval grass shrimp were approximately 18-fold more sensitive to lambda-cyhalothrin than the mysids. Larval grass shrimp were similar in sensitivity to adult grass shrimp for cypermethrin, deltamethrin, and phenothrin, but larvae were approximately twice as sensitive to lambda-cyhalothrin and permethrin as adult shrimp. Acute toxicity to estuarine crustaceans occurred at low nanogram per liter concentrations of some pyrethroids, illustrating the need for careful regulation of the use of pyrethroid compounds in the coastal zone. Copyright © 2013 Wiley Periodicals, Inc., a Wiley company.

Trace metal contamination in commercial fish and crustaceans collected from coastal area of Bangladesh and health risk assessment.

PubMed

Raknuzzaman, Mohammad; Ahmed, Md Kawser; Islam, Md Saiful; Habibullah-Al-Mamun, Md; Tokumura, Masahiro; Sekine, Makoto; Masunaga, Shigeki

2016-09-01

Trace metals contamination in commercial fish and crustaceans have become a great problem in Bangladesh. This study was conducted to determine seven trace metals concentration (Cr, Ni, Cu, Zn, As, Cd, and Pb) in some commercial fishes and crustaceans collected from coastal areas of Bangladesh. Trace metals in fish samples were in the range of Cr (0.15 - 2.2), Ni (0.1 - 0.56), Cu (1.3 - 1.4), Zn (31 - 138), As (0.76 - 13), Cd (0.033 - 0.075), and Pb (0.07 - 0.63 mg/kg wet weight (ww)), respectively. Arsenic (13 mg/kg ww) and Zn (138 mg/kg ww) concentrations were remarkably high in fish of Cox's Bazar due to the interference of uncontrolled huge hatcheries and industrial activities. The elevated concentrations of Cu (400), Zn (1480), and As (53 mg/kg ww) were also observed in crabs of Cox's Bazar which was considered as an absolutely discrepant aquatic species with totally different bioaccumulation pattern. Some metals in fish and crustaceans exceeded the international quality guidelines. Estimated daily intake (EDI) and target cancer risk (TR) revealed high dietary intake of As and Pb, which was obviously a matter of severe public health issue of Bangladeshi coastal people which should not be ignored and concentrate our views to solve this problem with an integrated approaches. Thus, continuous monitoring of these toxic trace elements in seafood and immediate control measure is recommended.

Identification and temporal expression of putative circadian clock transcripts in the amphipod crustacean Talitrus saltator

PubMed Central

O’Grady, Joseph F.; Hoelters, Laura S.; Swain, Martin T.

2016-01-01

Background Talitrus saltator is an amphipod crustacean that inhabits the supralittoral zone on sandy beaches in the Northeast Atlantic and Mediterranean. T. saltator exhibits endogenous locomotor activity rhythms and time-compensated sun and moon orientation, both of which necessitate at least one chronometric mechanism. Whilst their behaviour is well studied, currently there are no descriptions of the underlying molecular components of a biological clock in this animal, and very few in other crustacean species. Methods We harvested brain tissue from animals expressing robust circadian activity rhythms and used homology cloning and Illumina RNAseq approaches to sequence and identify the core circadian clock and clock-related genes in these samples. We assessed the temporal expression of these genes in time-course samples from rhythmic animals using RNAseq. Results We identified a comprehensive suite of circadian clock gene homologues in T. saltator including the ‘core’ clock genes period (Talper), cryptochrome 2 (Talcry2), timeless (Taltim), clock (Talclk), and bmal1 (Talbmal1). In addition we describe the sequence and putative structures of 23 clock-associated genes including two unusual, extended isoforms of pigment dispersing hormone (Talpdh). We examined time-course RNAseq expression data, derived from tissues harvested from behaviourally rhythmic animals, to reveal rhythmic expression of these genes with approximately circadian period in Talper and Talbmal1. Of the clock-related genes, casein kinase IIβ (TalckIIβ), ebony (Talebony), jetlag (Taljetlag), pigment dispensing hormone (Talpdh), protein phosphatase 1 (Talpp1), shaggy (Talshaggy), sirt1 (Talsirt1), sirt7 (Talsirt7) and supernumerary limbs (Talslimb) show temporal changes in expression. Discussion We report the sequences of principle genes that comprise the circadian clock of T. saltator and highlight the conserved structural and functional domains of their deduced cognate proteins. Our

The water flea Daphnia magna (Crustacea, Cladocera) as a test species for screening and evaluation of chemicals with endocrine disrupting effects on crustaceans.

PubMed

Tatarazako, Norihisa; Oda, Shigeto

2007-02-01

The water flea Daphnia magna (Crustacea, Cladocera) is a cyclical parthenogen, which can reproduce both by parthenogenesis and by sexual reproduction. With its ease of handling in the laboratory, several testing methods using D. magna exist for regulatory toxicity testing. Recently, several studies revealed that one of the major hormone groups in insects and crustaceans, juvenile hormones, are involved in the shift of reproductive mode from parthenogenesis to sexual reproduction (production of male neonates). Using offspring sex ratio as a new endpoint has made it possible to identify chemicals with juvenile hormone-like effects on crustaceans. The testing method using D. magna, in which offspring sex ratio is incorporated as a new endpoint, is now being proposed to the OECD as an enhanced version of the existing OECD Test Guideline 211: Daphnia magna reproduction test. No other clear-cut endpoint for identifying juvenile-hormone disrupting effects has ever been found in crustaceans than the induction of male neonates production in cladocerans. In this regard, it is expected that testing methods using D. magna are suitable for screening and risk assessment of chemicals with juvenile-hormone disrupting effects.

Neurogenesis in the water flea Daphnia magna (Crustacea, Branchiopoda) suggests different mechanisms of neuroblast formation in insects and crustaceans.

PubMed

Ungerer, Petra; Eriksson, Bo Joakim; Stollewerk, Angelika

2011-09-01

Within euarthropods, the morphological and molecular mechanisms of early nervous system development have been analysed in insects and several representatives of chelicerates and myriapods, while data on crustaceans are fragmentary. Neural stem cells (neuroblasts) generate the nervous system in insects and in higher crustaceans (malacostracans); in the remaining euarthropod groups, the chelicerates (e.g. spiders) and myriapods (e.g. millipedes), neuroblasts are missing. In the latter taxa, groups of neural precursors segregate from the neuroectoderm and directly differentiate into neurons and glial cells. In all euarthropod groups, achaete-scute homologues are required for neuroblast/neural precursor group formation. In the insects Drosophila melanogaster and Tribolium castaneum achaete-scute homologues are initially expressed in clusters of cells (proneural clusters) in the neuroepithelium but expression becomes restricted to the future neuroblast. Subsequently genes such as snail and prospero are expressed in the neuroblasts which are required for asymmetric division and differentiation. In contrast to insects, malacostracan neuroblasts do not segregate into the embryo but remain in the outer neuroepithelium, similar to vertebrate neural stem cells. It has been suggested that neuroblasts are present in another crustacean group, the branchiopods, and that they also remain in the neuroepithelium. This raises the questions how the molecular mechanisms of neuroblast selection have been modified during crustacean and insect evolution and if the segregation or the maintenance of neuroblasts in the neuroepithelium represents the ancestral state. Here we take advantage of the recently published Daphnia pulex (branchiopod) genome and identify genes in Daphnia magna that are known to be required for the selection and asymmetric division of neuroblasts in the fruit fly D. melanogaster. We unambiguously identify neuroblasts in D. magna by molecular marker gene expression and

Abundance, composition, and distribution of crustacean zooplankton in relation to hypolimnetic oxygen depletion in west-central Lake Erie

USGS Publications Warehouse

Heberger, Roy F.; Reynolds, James B.

1977-01-01

Samples of crustacean zooplankton were collected monthly in west-central Lake Erie in April and June to October 1968, and in July and August 1970, before and during periods of hypolimnetic dissolved oxygen (DO) depletion. The water column at offshore stations was thermally stratified from June through September 1968, and the hypolimnion contained no DO in mid-August of 1968 or 1970. Composition, abundance, and vertical distribution of crustacean zooplankton changed coincidentally with oxygen depletion. From July to early August, zooplankton abundance dropped 79% in 1968 and 50% in 1970. The declines were attributed largely to a sharp decrease in abundance of planktonic Cyclops bicuspidatus thomasi. Zooplankton composition shifted from mainly cyclopoid copepods in July to mainly cladocerans and copepod nauplii in middle to late August. We believe that mortality of adults and dormancy of copepodites in response to anoxia was the probable reason for the late summer decline in planktonic C. b. thomasi.

From the Palaeontological Collection of the Universalmuseum Joanneum – The Cenozoic Decapod Crustaceans (Crustacea: Malacostraca: Decapoda)

PubMed Central

Hyžný, Matúš; Gross, Martin

2017-01-01

Cenozoic decapod crustaceans housed in the collections of the Universalmuseum Joanneum (Graz, Austria) are reviewed. Previous descriptions, geographic and stratigraphic provenance and collection history are discussed. Altogether 72 specimens are figured, including five holotypes. Taxonomic affinity of previously unpublished material is addressed. Gebiacantha sp. from the middle Miocene of Wetzelsdorf is the first fossil record of the genus from the Paratethys. PMID:28239309

Self-Assembled, Iridescent, Crustacean-Mimetic Nanocomposites with Tailored Periodicity and Layered Cuticular Structure.

PubMed

Wang, Baochun; Walther, Andreas

2015-11-24

Natural high-performance materials inspire the pursuit of ordered hard/soft nanocomposite structures at high fractions of reinforcements and with balanced molecular interactions. Herein, we develop a facile, waterborne self-assembly pathway to mimic the multiscale cuticle structure of the crustacean armor by combining hard reinforcing cellulose nanocrystals (CNCs) with soft poly(vinyl alcohol) (PVA). We show iridescent CNC nanocomposites with cholesteric liquid-crystal structure, in which different helical pitches and photonic band gaps can be realized by varying the CNC/PVA ratio. We further show that multilayered crustacean-mimetic materials with tailored periodicity and layered cuticular structure can be obtained by sequential preparation pathways. The transition from a cholesteric to a disordered structure occurs for a critical polymer concentration. Correspondingly, we find a transition from stiff and strong mechanical behavior to materials with increasing ductility. Crack propagation studies using scanning electron microscopy visualize the different crack growth and toughening mechanisms inside cholesteric nanocomposites as a function of the interstitial polymer content for the first time. Different extents of crack deflection, layered delamination, ligament bridging, and constrained microcracking can be observed. Drawing of highly plasticized films sheds light on the mechanistic details of the transition from a cholesteric/chiral nematic to a nematic structure. The study demonstrates how self-assembly of biobased CNCs in combination with suitable polymers can be used to replicate a hierarchical biological structure and how future design of these ordered multifunctional nanocomposites can be optimized by understanding mechanistic details of deformation and fracture.

MARS: A protein family involved in the formation of vertical skeletal elements.

PubMed

Abehsera, Shai; Peles, Shani; Tynyakov, Jenny; Bentov, Shmuel; Aflalo, Eliahu D; Li, Shihao; Li, Fuhua; Xiang, Jianhai; Sagi, Amir

2017-05-01

Vertical organizations of skeletal elements are found in various vertebrate teeth and invertebrate exoskeletons. The molecular mechanism behind the development of such structural organizations is poorly known, although it is generally held that organic matrix proteins play an essential role. While most crustacean cuticular organizations exhibit horizontal chitinous layering, a typical vertical organization is found towards the surface of the teeth in the mandibles of the crayfish Cherax quadricarinatus. Candidate genes encoding for mandible-forming structural proteins were mined in C. quadricarinatus molt-related transcriptomic libraries by using a binary patterning approach. A new protein family, termed the Mandible Alanine Rich Structural (MARS) protein family, with a modular sequence design predicted to form fibers, was found. Investigations of spatial and temporal expression of the different MARS genes suggested specific expression in the mandibular teeth-forming epithelium, particularly during the formation of the chitinous vertical organization. MARS loss-of-function RNAi experiments resulted in the collapse of the organization of the chitin fibers oriented vertically to the surface of the crayfish mandibular incisor tooth. A general search of transcriptomic libraries suggested conservation of MARS proteins across a wide array of crustaceans. Our results provide a first look into the molecular mechanism used to build the complex crustacean mandible and into the specialized vertical structural solution that has evolved in skeletal elements. Copyright © 2017 Elsevier Inc. All rights reserved.

Venomics of Remipede Crustaceans Reveals Novel Peptide Diversity and Illuminates the Venom's Biological Role.

PubMed

von Reumont, Björn M; Undheim, Eivind A B; Jauss, Robin-Tobias; Jenner, Ronald A

2017-07-26

We report the first integrated proteomic and transcriptomic investigation of a crustacean venom. Remipede crustaceans are the venomous sister group of hexapods, and the venom glands of the remipede Xibalbanus tulumensis express a considerably more complex cocktail of proteins and peptides than previously thought. We identified 32 venom protein families, including 13 novel peptide families that we name xibalbins, four of which lack similarities to any known structural class. Our proteomic data confirm the presence in the venom of 19 of the 32 families. The most highly expressed venom components are serine peptidases, chitinase and six of the xibalbins. The xibalbins represent Inhibitory Cystine Knot peptides (ICK), a double ICK peptide, peptides with a putative Cystine-stabilized α-helix/β-sheet motif, a peptide similar to hairpin-like β-sheet forming antimicrobial peptides, two peptides related to different hormone families, and four peptides with unique structural motifs. Remipede venom components represent the full range of evolutionary recruitment frequencies, from families that have been recruited into many animal venoms (serine peptidases, ICKs), to those having a very narrow taxonomic range (double ICKs), to those unique for remipedes. We discuss the most highly expressed venom components to shed light on their possible functional significance in the predatory and defensive use of remipede venom, and to provide testable ideas for any future bioactivity studies.

Molecular, Biochemical, and Dietary Regulation Features of α-Amylase in a Carnivorous Crustacean, the Spiny Lobster Panulirus argus.

PubMed

Rodríguez-Viera, Leandro; Perera, Erick; Martos-Sitcha, Juan Antonio; Perdomo-Morales, Rolando; Casuso, Antonio; Montero-Alejo, Vivian; García-Galano, Tsai; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel

2016-01-01

Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype) in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase.

Molecular, Biochemical, and Dietary Regulation Features of α-Amylase in a Carnivorous Crustacean, the Spiny Lobster Panulirus argus

PubMed Central

Martos-Sitcha, Juan Antonio; Perdomo-Morales, Rolando; Casuso, Antonio; Montero-Alejo, Vivian; García-Galano, Tsai; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel

2016-01-01

Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype) in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase. PMID:27391425

Both Low Temperature and Shorter Duration of Food Availability Delay Testicular Regression and Affect the Daily Cycle in Body Temperature in a Songbird.

PubMed

Dawson, Alistair

Photoperiodic control of reproduction in birds is based on two processes, a positive effect leading to gonadal maturation and an inhibitory effect subsequently inducing regression. Nonphotoperiodic cues can modulate photoperiodic control, particularly the inhibitory process. In previous studies of common starlings (Sturnus vulgaris), (1) restriction of food availability to 8 h after dawn had little effect on testicular maturation but dramatically delayed subsequent regression and (2) lower ambient temperature also had little effect during maturation but delayed regression. Could the effects of food restriction and temperature share a common underlying mechanism? Four groups of starlings were kept on a simulated natural cycle in photoperiod in a 2 × 2 factorial experimental design. Two groups were held under an ambient temperature of 16°C, and the other two were held under 6°C. One of each of these groups had food provided ad lib., and in the other two groups access to food was denied 7 h after dawn. In both the ad lib. food groups and the food-restricted groups, lower temperature had little effect on testicular maturation but delayed subsequent regression and molt. In both the 16°C groups and the 6°C groups, food restriction had no effect on testicular maturation but delayed regression and molt. The daily cycle in body temperature was recorded in all groups when the photoperiod had reached 12L∶12D, the photoperiod at which regression is initiated. In both 6°C groups, nighttime body temperature was lower than in the 16°C groups, a characteristic of shorter photoperiods. In the two ad lib. food groups high daytime temperature was maintained until dusk, whereas in the two food-restricted groups body temperature began to decrease after food withdrawal. Thus, both lower temperature and food restriction delayed regression, as if the photoperiod was shorter than it actually was, and both resulted in daily cycles in body temperature that reflected cycles under

On the brain of a crustacean: a morphological analysis of CaMKII expression and its relation to sensory and motor pathways.

PubMed

Ammar, Dib; Nazari, Evelise M; Müller, Yara M R; Allodi, Silvana

2013-01-01

Calcium/calmodulin kinase II (CaMKII) is a Ca(2+)-activated enzyme that is abundant in vertebrate and invertebrate brains. However, its characterization is poorly addressed in the nervous system of crustaceans, and, to our knowledge, no studies have determined the microanatomical location of CaMKII in a crustacean species. In this study, we found labeling of CaMKII in the eyestalk and brain of the prawn Macrobrachium acanthurus, by means of immunohistochemistry and Western blotting. Antibodies against neuron (ß tubulin III), glutamate receptor (GluA1), and FMRFamide were used in order to further characterize the CaMKII-labeled cells in the brain. In the eyestalk, strong labeling with CaMKII was observed in the photoreceptors. These cells, especially in the rhabdom, were also reactive to anti-ß tubulin III, whereas the pigment cells were labeled with anti-CaMKII. GluA1 co-located with CaMKII in the photoreceptors. Also, CaMKII appeared in the same sites as FMRFamide in the deutocerebrum, including the olfactory lobe, and in the tritocerebrum, specifically in the antennular neuropil, indicating that the synaptic areas in these regions may be related to sensory-motor processing. In the brain, the identification of cells and regions that express CaMKII contributes to the understanding of the processing of neural connections and the modulating role of CaMKII in decapod crustaceans.

Green synthesis palladium nanoparticles mediated by white tea (Camellia sinensis) extract with antioxidant, antibacterial, and antiproliferative activities toward the human leukemia (MOLT-4) cell line.

PubMed

Azizi, Susan; Mahdavi Shahri, Mahnaz; Rahman, Heshu Sulaiman; Rahim, Raha Abdul; Rasedee, Abdullah; Mohamad, Rosfarizan

2017-01-01

Among nanoparticles used for medical applications, palladium nanoparticles (PdNPs) are among the least investigated. This study was undertaken to develop PdNPs by green synthesis using white tea (W.tea; Camellia sinensis ) extract to produce the Pd@W.tea NPs. The Pd@W.tea NPs were characterized by UV-vis spectroscopy and X-ray diffractometry, and evaluated with transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The Pd@W.tea NPs were spherical (size 6-18 nm) and contained phenols and flavonoids acquired from the W.tea extract. Pd@W.tea NPs has good 1-diphenyl-2-picrylhydrazyl (DPPH), OH, and NO-scavenging properties as well as antibacterial effects toward Staphylococcus epidermidis and Escherichia coli . MTT assay showed that Pd@W.tea NPs (IC 50 =0.006 μM) were more antiproliferative toward the human leukemia (MOLT-4) cells than the W.tea extract (IC 50 =0.894 μM), doxorubicin (IC 50 =2.133 μM), or cisplatin (IC 50 =0.013 μM), whereas they were relatively innocuous for normal human fibroblast (HDF-a) cells. The anticancer cell effects of Pd@W.tea NPs are mediated through the induction of apoptosis and G2/M cell-cycle arrest.

Serotonin and aggressive motivation in crustaceans: altering the decision to retreat.

PubMed

Huber, R; Smith, K; Delago, A; Isaksson, K; Kravitz, E A

1997-05-27

In crustaceans, as in most animal species, the amine serotonin has been suggested to serve important roles in aggression. Here we show that injection of serotonin into the hemolymph of subordinate, freely moving animals results in a renewed willingness of these animals to engage the dominants in further agonistic encounters. By multivariate statistical analysis, we demonstrate that this reversal results principally from a reduction in the likelihood of retreat and an increase in the duration of fighting. Serotonin infusion does not alter other aspects of fighting behavior, including which animal initiates an encounter, how quickly fighting escalates, or which animal eventually retreats. Preliminary studies suggest that serotonin uptake plays an important role in this behavioral reversal.

The biological effects of ionising radiation on Crustaceans: A review.

PubMed

Fuller, Neil; Lerebours, Adélaïde; Smith, Jim T; Ford, Alex T

2015-10-01

Historic approaches to radiation protection are founded on the conjecture that measures to safeguard humans are adequate to protect non-human organisms. This view is disparate with other toxicants wherein well-developed frameworks exist to minimise exposure of biota. Significant data gaps for many organisms, coupled with high profile nuclear incidents such as Chernobyl and Fukushima, have prompted the re-evaluation of our approach toward environmental radioprotection. Elucidating the impacts of radiation on biota has been identified as priority area for future research within both scientific and regulatory communities. The crustaceans are ubiquitous in aquatic ecosystems, comprising greater than 66,000 species of ecological and commercial importance. This paper aims to assess the available literature of radiation-induced effects within this subphylum and identify knowledge gaps. A literature search was conducted pertaining to radiation effects on four endpoints as stipulated by a number of regulatory bodies: mortality, morbidity, reproduction and mutation. A major finding of this review was the paucity of data regarding the effects of environmentally relevant radiation doses on crustacean biology. Extremely few studies utilising chronic exposure durations or wild populations were found across all four endpoints. The dose levels at which effects occur was found to vary by orders of magnitude thus presenting difficulties in developing phyla-specific benchmark values and reference levels for radioprotection. Based on the limited data, mutation was found to be the most sensitive endpoint of radiation exposure, with mortality the least sensitive. Current phyla-specific dose levels and limits proposed by major regulatory bodies were found to be inadequate to protect species across a range of endpoints including morbidity, mutation and reproduction and examples are discussed within. These findings serve to prioritise areas for future research that will significantly

Differences in response of two model estuarine crustaceans after lethal and sublethal exposures to chlorpyrifos.

PubMed

Key, Peter B; Simonik, Elizabeth; Kish, Nicole; Chung, Katy W; Fulton, Michael H

2013-01-01

This study assessed the in vitro and in vivo effects of an acetylcholinesterase enzyme inhibitor (chlorpyrifos) in two estuarine crustaceans: grass shrimp (Palaemonetes pugio) and mysid (Americamysis bahia). The differences in response were quantified after lethal and sublethal exposures to chlorpyrifos and in vitro assays with chlorpyrifos-oxon. Results from the in vitro experiments indicated that the target enzyme, acetylcholinesterase (AChE), in the two species was similar in sensitivity to chlorpyrifos inhibition with IC50s of 0.98 nM and 0.89 nM for grass shrimp and mysids, respectively. In vivo experiments showed that mysids were significantly more sensitive to chlorpyrifos-induced AChE inhibition after 24 h of exposure. The in vivo EC50s for AChE inhibition were 1.23 μg L(-1) for grass shrimp and 0.027 μg L(-1) for mysids. Median lethal concentrations (24h LC50 values) were 1.06 μg L(-1) for grass shrimp and 0.068 μg L(-1) for mysids. The results suggest that differences in the response of these two crustaceans are likely related to differences in uptake and metabolism rather than target site sensitivity.

The biological effects of antidepressants on the molluscs and crustaceans: a review.

PubMed

Fong, Peter P; Ford, Alex T

2014-06-01

Antidepressants are among the most commonly detected human pharmaceuticals in the aquatic environment. Since their mode of action is by modulating the neurotransmitters serotonin, dopamine, and norepinephrine, aquatic invertebrates who possess transporters and receptors sensitive to activation by these pharmaceuticals are potentially affected by them. We review the various types of antidepressants, their occurrence and concentrations in aquatic environments, and the actions of neurohormones modulated by antidepressants in molluscs and crustaceans. Recent studies on the effects of antidepressants on these two important groups show that molluscan reproductive and locomotory systems are affected by antidepressants at environmentally relevant concentrations. In particular, antidepressants affect spawning and larval release in bivalves and disrupt locomotion and reduce fecundity in snails. In crustaceans, antidepressants affect freshwater amphipod activity patterns, marine amphipod photo- and geotactic behavior, crayfish aggression, and daphnid reproduction and development. We note with interest the occurrence of non-monotonic dose responses curves in many studies on effects of antidepressants on aquatic animals, often with effects at low concentrations, but not at higher concentrations, and we suggest future experiments consider testing a broader range of concentrations. Furthermore, we consider invertebrate immune responses, genomic and transcriptomic sequencing of invertebrate genes, and the ever-present and overwhelming question of how contaminant mixtures could affect the action of neurohormones as topics for future study. In addressing the question, if antidepressants affect aquatic invertebrates at concentrations currently found in the environment, there is strong evidence to suggest the answer is yes. Furthermore, the examples highlighted in this review provide compelling evidence that the effects could be quite multifaceted across a variety of biological

Barremian decapod crustaceans from Serre de Bleyton (Drôme, SE France)

PubMed Central

Hyžný, Matúš; Kroh, Andreas

2015-01-01

Based on mostly small-sized isolated cheliped fingers, a new decapod crustacean assemblage is described from the Barremian of Serre de Bleyton (Drôme, SE France). The assemblage is composed mostly of representatives of the crab family Dynomenidae. In addition, remains of astacidean lobsters, axiidean shrimps, paguroid hermit crabs and brachyurous crabs of the families Necrocarcinidae and ?Cenomanocarcinidae occur in low numbers. Graptocarcinus moosleitneri (Dynomenidae) and ?Paranecrocarcinus schloegli (Necrocarcinidae) are introduced as new species. They both exhibit presence of multi-setal pores on dactyli that are interpreted as parts of a sieving mechanism used in feeding. The stratigraphic range of Graptocarcinus is extended herein to the Barremian. PMID:26097276

Multiple functions of the crustacean gill: osmotic/ionic regulation, acid-base balance, ammonia excretion, and bioaccumulation of toxic metals

PubMed Central

Henry, Raymond P.; Lucu, Čedomil; Onken, Horst; Weihrauch, Dirk

2012-01-01

The crustacean gill is a multi-functional organ, and it is the site of a number of physiological processes, including ion transport, which is the basis for hemolymph osmoregulation; acid-base balance; and ammonia excretion. The gill is also the site by which many toxic metals are taken up by aquatic crustaceans, and thus it plays an important role in the toxicology of these species. This review provides a comprehensive overview of the ecology, physiology, biochemistry, and molecular biology of the mechanisms of osmotic and ionic regulation performed by the gill. The current concepts of the mechanisms of ion transport, the structural, biochemical, and molecular bases of systemic physiology, and the history of their development are discussed. The relationship between branchial ion transport and hemolymph acid-base regulation is also treated. In addition, the mechanisms of ammonia transport and excretion across the gill are discussed. And finally, the toxicology of heavy metal accumulation via the gill is reviewed in detail. PMID:23162474

Flapper Valve and Hayfork: Functional anatomy and taxonomic potential of the Gastric Mill of Bairdioidea (Ostracoda, Podocopida).

PubMed

Maddocks, Rosalie F

2018-02-07

The chewing apparatus of the Bairdioidea has been described just once and is rarely illustrated, but it might have more taxonomic significance than commonly supposed. It is constructed as a flapper valve (hinged check valve), which is unique among Ostracoda and unusual among animals. It projects into the midgut and is substantially enveloped by it. It serves three functions: to move bites of food into the stomach, to close the esophagus against back-flow, and to pack strands of food and mucus onto the rotating food ball. It is probably less effective for macerating the food to reduce particle size. Two braces anchor this structure to the lateral wall of the forehead. It is lined by cuticle that is shed at each molt, and the formation of food balls is interrupted during molting. In its construction and action, this apparatus is quite unlike the gastric mill of decapod crustaceans, and it shows only distant homology to the dorsal Wulst of Cypridoidea. Some architectural details differ among families and genera. The well-sclerotized plate has some potential for fossil preservation in exceptional circumstances. A revised anatomical analysis is presented, together with an annotated glossary of terms.

INFLUENCE OF SALINITY ON HABITAT UTILIZATION OF OYSTER REEFS BY RESIDENT FISHES AND DECAPOD CRUSTACEANS IN THE CALOOSAHATCHEE ESTUARY, FLORIDA.

EPA Science Inventory

A spatiotemporal comparison of habitat suitability of oyster reefs for fishes and decapod crustaceans was conducted for the lower Caloosahatchee Estuary, Florida. Lift nets (1-m2) containing 5 liters (volume displacement) of oyster clusters were deployed monthly at three sites al...

Lethal effects of five molt inhibitors fed to the western spruce budworm (Choristoneura occidentalis Freeman) (Lepidoptera: Tortricidae) and the Douglas-fir tussock moth (Orgyia pseudotsugata [McDonnough]) (Lepidoptera: Lymantriidae)

Treesearch

N.G. Rappaport; J.L. Robertson

1981-01-01

Five insect molt inhibitors (MI's) were mixed with artificial diet and fed to 3rd and 6th stage western spruce budworm (Choristoneura occidentalis) larvae and 2nd stage Douglas-fir tussock moth (Orgyia pseudotsugata) larvae. In general, tussock moth larvae were more susceptible that western spruce budworm larvae to these MI...

Identification of a crustacean β-1,3-glucanase related protein as a pattern recognition protein in antibacterial response.

PubMed

Chai, Lian-Qin; Meng, Jing-Hui; Gao, Jie; Xu, Yi-Hui; Wang, Xian-Wei

2018-06-02

Prophenoloxidase (proPO) activating system is an important immune response for arthropods. β-1, 3-glucanase related protein (previously named as lipopolysaccharide and β-1, 3-glucan binding protein (LGBP) in crustaceans) is a typical pattern recognition receptor family involved in the proPO activation by recognizing the invading microbes. In this study, we pay special attention to a bacteria-induced β-1,3-glucanase related protein from red swamp crayfish Procambarus clarkii, an important aquaculture specie in China. This protein, designated PcBGRP, was found a typical member of crustacean BGRP family with the glucanase-related domain and the characteristic motifs. PcBGRP was expressed in hemcoyes and hepatopancreas, and its expression could be induced by the carbohydrate and bacteria stimulants. The induction by lipopolysaccharide (LPS) and β-1,3-glucan (βG) was more significant than by peptidoglycan (PG). The response of PcBGRP to the native Gram-negative bacterial pathogen Aeromonas hydrophila was more obvious than to Gram-positive bacteria. Using RNA interference and recombinant protein, PcBGRP was found to protect crayfish from A. hydrophila infection revealed by the survival test and morphological analysis. A mechanism study found PcBGRP could bind LPS and βG in a dose-dependent manner, and the LPS recognizing ability determined the Gram-negative bacterium binding activity of PcBGRP. PcBGRP was found to enhance the PO activation both in vitro and in vivo, and the protective role was related to the PO activating ability of PcBGRP. This study emphasized the role of BGRP family in crustacean immune response, and provided new insight to the immunity of red swamp crayfish which suffered serious disease during the aquaculture in China. Copyright © 2018 Elsevier Ltd. All rights reserved.

Stable isotopes suggest low site fidelity in Bar-Headed Geese (Anser indicus) in Mongolia: Implications for disease transmission

USGS Publications Warehouse

Bridge, Eli S.; Kelly, Jeffrey F.; Xiangming Xiao,; Batbayar, Nyambayar; Natsagdorj, Tseveenmyadag; Hill, Nichola J.; Takekawa, John Y.; Hawkes, Lucy A.; Bishop, Charles M.; Butler, Patrick J.; Newman, Scott H.

2015-01-01

Population connectivity is an important consideration in studies of disease transmission and biological conservation, especially with regard to migratory species. Determining how and when different subpopulations intermingle during different phases of the annual cycle can help identify important geographical regions or features as targets for conservation efforts and can help inform our understanding of continental-scale disease transmission. In this study, stable isotopes of hydrogen and carbon in contour feathers were used to assess the degree of molt-site fidelity among Bar-headed Geese (Anser indicus) captured in north-central Mongolia. Samples were collected from actively molting Bar-headed Geese (n = 61), and some individual samples included both a newly grown feather (still in sheath) and an old, worn feather from the bird's previous molt (n = 21). Although there was no difference in mean hydrogen isotope ratios for the old and new feathers, the isotopic variance in old feathers was approximately three times higher than that of the new feathers, which suggests that these birds use different and geographically distant molting locations from year to year. To further test this conclusion, online data and modeling tools from the isoMAP website were used to generate probability landscapes for the origin of each feather. Likely molting locations were much more widespread for old feathers than for new feathers, which supports the prospect of low molt-site fidelity. This finding indicates that population connectivity would be greater than expected based on data from a single annual cycle, and that disease spread can be rapid even in areas like Mongolia where Bar-headed Geese generally breed in small isolated groups.

Release of specific proteins from nuclei of HL-60 and MOLT-4 cells by antitumor drugs having affinity to nucleic acids.

PubMed

Lassota, P; Melamed, M R; Darzynkiewicz, Z

The binding sites for mitoxantrone (MIT), Ametantrone (AMT), doxorubicin (DOX), actinomycin D (AMD) and ethidium bromide (EB) in nuclei from exponentially growing and differentiating human promyelocytic HL-60 and lymphocytic leukemic MOLT-4 cells were studied by gel electrophoresis of proteins selectively released during titration of these nuclei with the drugs. Each drug at different drug: DNA binding ratios resulted in a characteristic pattern of protein elution and/or retention. For example, in nuclei from exponentially growing HL-60 cells, MIT affected 44 nuclear proteins that were different from those affected by EB; of these 29 were progressively released at increasing MIT:DNA ratios, 11 were transiently released (i.e. only at a low MIT:DNA ratio) and 4 entrapped. Patterns of proteins displaced from nuclei of exponentially growing HL-60 cells differed from those of cells undergoing myeloid differentiation as well as from those of exponentially growing MOLT-4 cells. The first effects were seen at a binding density of approximately one drug molecule per 10-50 base pairs of DNA. The observed selective displacement of proteins may reflect drug-altered affinity of the binding sites for those proteins, for example due to a change of nucleic acid or protein conformation upon binding the ligand. The data show that the binding site(s) for each of the ligands studied is different and the differences correlate with variability in chemical structure between the ligands. The nature of the drug-affected proteins may provide clues regarding antitumor or cytotoxic mechanisms of drug action.

Parasite transfer from crustacean to fish hosts in the Lübeck Bight, SW Baltic Sea

NASA Astrophysics Data System (ADS)

Zander, C. D.; Groenewold, S.; Strohbach, U.

1994-03-01

Four helminth parasites out of 19 species found in the Lübeck Bight, Baltic Sea, were chosen for investigations on the transfer from invertebrate to small-sized fish hosts: larvae of the tapeworms Schistocephalus sp. and Bothriocephalus sp. (Cestoda) living in planktonic copepods as primary hosts; Podocotyle atomon (Digenea) and Hysterothylacium sp. (Nematoda) were found in benthic crustaceans, especially Gammarus spp. These hosts were the prey of 3 gobiid fishes, Gobiusculus flavescens (feeding mainly on plankton), Pomatoschistus minutus (preferring benthos), and P. pictus (feeding more on plankton than benthos). Because the fishes selected smaller sizes of crustaceans, they ingested all stages of the copepods but only the smaller-sized groups of gammarids which were often less infested by parasites. In order to evaluate the probability for a fish to be parasitized by a helminth, an infestation potential index (IP) was calculated. Podocotyle atomon and Hysterothylacium sp. revealed an IP which was far lower in gobies than expected when the prevalences of the previous hosts were taken into consideration. The IP of tapeworm larvae was mainly influenced by the feeding pressure of the gobiid predators, which might change with developmental stage and season. It is concluded that parasite transfer to the next host decreases when sizes of prey and predator differ only moderately. This mechanism can reduce the numbers of parasites transferred to less suitable or wrong hosts.

Venomics of Remipede Crustaceans Reveals Novel Peptide Diversity and Illuminates the Venom’s Biological Role

PubMed Central

von Reumont, Björn M.; Undheim, Eivind A. B.; Jauss, Robin-Tobias; Jenner, Ronald A.

2017-01-01

We report the first integrated proteomic and transcriptomic investigation of a crustacean venom. Remipede crustaceans are the venomous sister group of hexapods, and the venom glands of the remipede Xibalbanus tulumensis express a considerably more complex cocktail of proteins and peptides than previously thought. We identified 32 venom protein families, including 13 novel peptide families that we name xibalbins, four of which lack similarities to any known structural class. Our proteomic data confirm the presence in the venom of 19 of the 32 families. The most highly expressed venom components are serine peptidases, chitinase and six of the xibalbins. The xibalbins represent Inhibitory Cystine Knot peptides (ICK), a double ICK peptide, peptides with a putative Cystine-stabilized α-helix/β-sheet motif, a peptide similar to hairpin-like β-sheet forming antimicrobial peptides, two peptides related to different hormone families, and four peptides with unique structural motifs. Remipede venom components represent the full range of evolutionary recruitment frequencies, from families that have been recruited into many animal venoms (serine peptidases, ICKs), to those having a very narrow taxonomic range (double ICKs), to those unique for remipedes. We discuss the most highly expressed venom components to shed light on their possible functional significance in the predatory and defensive use of remipede venom, and to provide testable ideas for any future bioactivity studies. PMID:28933727

Life Cycle and Immature Stages of the Arctiid Moth, Phoenicoprocta capistrata

PubMed Central

Rodríguez-Loeches, Laura; Barro, Alejandro

2008-01-01

Phoenicoprocta capistrata (Fabricius 1775) (Lepidoptera: Arctiidae) is an arctiid moth reported for the Caribbean and Brazil, whose immature stages and life cycle are unknown. In this study, and for the first time, a host plant is registered and the immature stages and the captivity life cycle are described using a Cuban population. Larvae feed on fowlsfoot, Serjania diversifolia (Jacq.) Radlk (Sapindales: Sapindaceae). One complete cohort was obtained from December of 2004 to February of 2005 and about 57 days lapsed from oviposition to adult emergence. The egg is light green-yellowish and semi-spherical. Most larvae developed through 6 or 7 instars, although there were individuals with 8 instars. The last instar has a cephalic capsule width of 2.04 ± 0.06 mm (n = 29) irrespective of the number of instars. The cephalic capsule growth curves of the larvae with 6 and 7 instars have different slopes, but both follow a geometric pattern consistent with the Dyar's rule. In each larval molt the setae types and the larvae coloration change. Adult females have two color morphs, one orange-reddish and the other blue. Female descendants of blue and red females differ in the proportion of color morphs, which could indicate the existence of a female-limited polymorphism phenomenon in this species. PMID:20345309

Effects of habitat structure on the epifaunal community in Mussismilia corals: does coral morphology influence the richness and abundance of associated crustacean fauna?

NASA Astrophysics Data System (ADS)

Nogueira, Marcos M.; Neves, Elizabeth; Johnsson, Rodrigo

2015-06-01

Coral habitat structures increase abundance and richness of organisms by providing niches, easy access to resources and refuge from predators. Corals harbor a great variety of animals; the variation in coral species morphology contributes to the heterogeneity and complexity of habitat types. In this report, we studied the richness and abundance of crustaceans (Decapoda, Copepoda, Peracarida and Ostracoda) associated with three species of Mussismilia exhibiting different growth morphologies, in two different coral reefs of the Bahia state (Caramuanas and Boipeba-Moreré, Brazil). Mussismilia hispida is a massive coral; M. braziliensis also has a massive growth pattern, but forms a crevice in the basal area of the corallum; M. harttii has a meandroid pattern. PERMANOVA analysis suggests significant differences in associated fauna richness among Mussismilia species, with higher values for M. harttii, followed by M. braziliensis and later by M. hispida. The same trend was observed for density, except that the comparison of M. braziliensis and M. hispida did not show differences. Redundancy and canonical correspondence analysis indicated that almost all of the crustacean species were more associated with the M. harttii colonies that formed a group clearly separated from colonies of M. braziliensis and M. hispida. We also found that the internal volume of interpolyp space, only present in M. harttii, was the most important factor influencing richness and abundance of all analyzed orders of crustaceans.

A Phylogenomic Solution to the Origin of Insects by Resolving Crustacean-Hexapod Relationships.

PubMed

Schwentner, Martin; Combosch, David J; Pakes Nelson, Joey; Giribet, Gonzalo

2017-06-19

Insects, the most diverse group of organisms, are nested within crustaceans, arguably the most abundant group of marine animals. However, to date, no consensus has been reached as to which crustacean taxon is the closest relative of hexapods. A majority of studies have proposed that Branchiopoda (e.g., fairy shrimps) is the sister group of Hexapoda [1-7]. However, these investigations largely excluded two equally important taxa, Remipedia and Cephalocarida. Other studies suggested Remipedia [8-11] or Remipedia + Cephalocarida [12, 13] as potential sister groups of hexapods, but they either did not include Cephalocarida or used only Sanger sequence data and morphology [9, 12]. Here we present the first phylogenomic study specifically addressing the origins of hexapods, including transcriptomes for two species each of Cephalocarida and Remipedia. Phylogenetic analyses of selected matrices, ranging from 81 to 1,675 orthogroups and up to 510,982 amino acid positions, clearly reject a sister-group relationship between Hexapoda and Branchiopoda [1-7]. Nonetheless, support for a hexapod sister-group relationship to Remipedia or to Cephalocarida-Remipedia was highly dependent on the employed analytical methodology. Further analyses assessing the effects of gene evolutionary rate and targeted taxon exclusion support Remipedia as the sole sister taxon of Hexapoda and suggest that the prior grouping of Remipedia + Cephalocarida is an artifact, possibly due to long branch attraction and compositional heterogeneity. We further conclude that terrestrialization of Hexapoda probably occurred in the late Cambrian to early Ordovician, an estimate that is independent of their proposed sister group [4, 8, 12, 14]. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immunochemical and immunocytochemical studies of the crustacean vitellogenesis-inhibiting hormone (VIH).

PubMed

Meusy, J J; Martin, G; Soyez, D; van Deijnen, J E; Gallo, J M

1987-09-01

Immunochemical investigations, using dot immunobinding assay (DIA) and enzyme-linked immunosorbent assay (ELISA), and immunocytochemical studies reveal the following new information about crustacean vitellogenesis-inhibiting hormone (VIH): (1) The structure of VIH is sufficiently different from that of the other sinus gland neuropeptides to allow a selective recognition of VIH by polyclonal antibodies. (2) From immunochemical criteria, VIH does not seem strictly species specific. The antisera raised against VIH of Homarus americanus cross-react with sinus gland extracts of Palaemonetes varians, Palaemon serratus, Macrobrachium rosenbergii, Carcinus maenas, and Porcellio dilatatus. (3) In the sinus gland of H. americanus, VIH immunoreactivity is localized mainly in electron-dense granules of medium size (110-185 nm in diameter) while, in P. dilatatus, the labeling is mostly on the largest granules (200-270 nm in diameter).

Changes in epizoic crustacean infestations during cetacean die-offs: the mass mortality of Mediterranean striped dolphins Stenella coeruleoalba revisited.

PubMed

Aznar, F J; Perdiguero, D; Pérez del Olmo, A; Repullés, A; Agustí, C; Raga, J A

2005-11-28

In the summer and autumn of 1990, a cetacean morbillivirus caused a massive epizootic mortality of striped dolphins Stenella coeruleoalba in the western Mediterranean. Previous circumstantial evidence suggested that the disease could also have increased host susceptibility to infestations with epizoic crustaceans. In this study we provide strong evidence supporting this hypothesis. We examined striped dolphins stranded along the Mediterranean central coast of Spain from 1981 to 2004 (n = 136), and recorded data on prevalence, intensity of infestation, size and reproductive status of 2 sessile crustacean species specific to cetaceans, the phoront cirriped Xenobalanus globicipitis and the mesoparasitic copepod Pennella balaenopterae. Compared with the pre-epizootic (n = 12) and post-epizootic (n = 62) dolphin samples, the following changes were noted in the dolphins stranded during the epizootic (n = 62): (1) the prevalence of both X. globicipitis and P. balaenopterae increased; (2) the intensity of X. globicipitis and P. balaenopterae infestations did not increase; indeed, it was even slightly lower than in the other periods, as was their degree of aggregation; (3) individuals of both species were smaller, and a higher proportion were non-gravid; (4) the 2 species tended to co-occur in the same dolphins, but their numbers did not co-vary. These patterns strongly suggest that, during the epizootic, there was a short-term increase in the probability of infestation of these 2 species because of the sudden rise in the population of susceptible hosts; the growth of the new recruits was limited by the early death of dolphins. The high susceptibility was likely related to the immunosuppressive effects of viral infection and the abnormally heavy loads of polychlorinated biphenyls found in sick dolphins; the level of inbreeding was also higher in dolphins from the 'epizootic' sample. Epizoic crustaceans could be suitable indicators of health in cetacean populations.

First Insights into the Subterranean Crustacean Bathynellacea Transcriptome: Transcriptionally Reduced Opsin Repertoire and Evidence of Conserved Homeostasis Regulatory Mechanisms

PubMed Central

Kim, Bo-Mi; Kang, Seunghyun; Ahn, Do-Hwan; Kim, Jin-Hyoung; Ahn, Inhye; Lee, Chi-Woo; Cho, Joo-Lae; Min, Gi-Sik; Park, Hyun

2017-01-01

Bathynellacea (Crustacea, Syncarida, Parabathynellidae) are subterranean aquatic crustaceans that typically inhabit freshwater interstitial spaces (e.g., groundwater) and are occasionally found in caves and even hot springs. In this study, we sequenced the whole transcriptome of Allobathynella bangokensis using RNA-seq. De novo sequence assembly produced 74,866 contigs including 28,934 BLAST hits. Overall, the gene sequences were most similar to those of the waterflea Daphnia pulex. In the A. bangokensis transcriptome, no opsin or related sequences were identified, and no contig aligned to the crustacean visual opsins and non-visual opsins (i.e. arthropsins, peropsins, and melaopsins), suggesting potential regressive adaptation to the dark environment. However, A. bangokensis expressed conserved gene family sets, such as heat shock proteins and those related to key innate immunity pathways and antioxidant defense systems, at the transcriptional level, suggesting that this species has evolved adaptations involving molecular mechanisms of homeostasis. The transcriptomic information of A. bangokensis will be useful for investigating molecular adaptations and response mechanisms to subterranean environmental conditions. PMID:28107438

Neuropeptide modulation of pattern-generating systems in crustaceans: comparative studies and approaches.

PubMed

Dickinson, Patsy S; Qu, Xuan; Stanhope, Meredith E

2016-12-01

Central pattern generators are subject to modulation by peptides, allowing for flexibility in patterned output. Current techniques used to characterize peptides include mass spectrometry and transcriptomics. In recent years, hundreds of neuropeptides have been sequenced from crustaceans; mass spectrometry has been used to identify peptides and to determine their levels and locations, setting the stage for comparative studies investigating the physiological roles of peptides. Such studies suggest that there is some evolutionary conservation of function, but also divergence of function even within a species. With current baseline data, it should be possible to begin using comparative approaches to ask fundamental questions about why peptides are encoded the way that they are and how this affects nervous system function. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pile-Driving Pressure and Particle Velocity at the Seabed: Quantifying Effects on Crustaceans and Groundfish.

PubMed

Miller, James H; Potty, Gopu R; Kim, Hui-Kwan

2016-01-01

We modeled the effects of pile driving on crustaceans, groundfish, and other animals near the seafloor. Three different waves were investigated, including the compressional wave, shear wave, and interface wave. A finite element (FE) technique was employed in and around the pile, whereas a parabolic equation (PE) code was used to predict propagation at long ranges from the pile. Pressure, particle displacement, and particle velocity are presented as a function of range at the seafloor for a shallow-water environment near Rhode Island. We discuss the potential effects on animals near the seafloor.

Structural and functional comparisons and production of recombinant crustacean hyperglycemic hormone (CHH) and CHH-like peptides from the mud crab Scylla olivacea.

PubMed

Chang, Chih-Chun; Tsai, Kuo-Wei; Hsiao, Nai-Wan; Chang, Cheng-Yen; Lin, Chih-Lung; Watson, R Douglas; Lee, Chi-Ying

2010-05-15

Sco-CHH and Sco-CHH-L (CHH-like peptide), two structural variants of the crustacean hyperglycemic hormone family identified in the mud crab (Scylla olivacea), are presumably alternatively spliced gene products. In this study, Sco-CHH and Sco-CHH-L were isolated from the tissues using high performance liquid chromatography. Identity of the native peptides was confirmed using mass spectrometric (MS) analyses of purified materials and of trypsin-digested peptide fragments. Additionally, characterizations using circular dichroism (CD) spectrometry revealed that the 2 peptides have similar CD spectral profiles, showing they are composed mainly of alpha-helices, and are similarly thermo-stable with a melting temperature of 74-75 degrees C. Results of bioassays indicated that Sco-CHH exerted hyperglycemic and molt-inhibiting activity, whereas Sco-CHH-L did not. Further, recombinant Sco-CHH-Gly (rSco-CHH-Gly, a glycine extended Sco-CHH) and Sco-CHH-L (rSco-CHH-L) were produced using an Escherichia coli expression system, refolded, and purified. rSco-CHH-Gly was further alpha-amidated at the C-terminal end to produce rSco-CHH. MS analyses of enzyme-digested peptide fragments of rSco-CHH-Gly and rSco-CHH-L showed that the two peptides share a common disulfide bond pattern: C7-C43, C23-C39, and C26-C52. Circular dichroism analyses and hyperglycemic assay revealed that rSco-CHH and rSco-CHH-L resemble their native counterparts, in terms of CD spectral profiles, melting curve profiles, and biological activity. rSco-CHH-Gly has a lower alpha-helical content (32%) than rSco-CHH (47%), a structural deviation that may be responsible for the significant decrease in the biological activity of rSco-CHH-Gly. Finally, modeled structure of Sco-CHH and Sco-CHH-L indicated that they are similarly folded, each with an N-terminal tail region and 4 alpha-helices. Putative surface residues located in corresponding positions of Sco-CHH and Sco-CHH-L but with side chains of different properties

Salinity-induced changes in gene expression from anterior and posterior gills of Callinectes sapidus (Crustacea: Portunidae) with implications for crustacean ecological genomics

PubMed Central

Havird, Justin C.; Mitchell, Reed T.; Henry, Raymond P.; Santos, Scott R.

2016-01-01

Decapods represent one of the most ecologically diverse taxonomic groups within crustaceans, making them ideal to study physiological processes like osmoregulation. However, prior studies have failed to consider the entire transcriptomic response of the gill – the primary organ responsible for ion transport – to changing salinity. Moreover, the molecular genetic differences between non-osmoregulatory and osmoregulatory gill types, as well as the hormonal basis of osmoregulation, remain underexplored. Here, we identified and characterized differentially expressed genes (DEGs) via RNA-Seq in anterior (non-osmoregulatory) and posterior (osmoregulatory) gills during high to low salinity transfer in the blue crab Callinectes sapidus, a well-studied model for crustacean osmoregulation. Overall, we confirmed previous expression patterns for individual ion transport genes and identified novel ones with salinity-mediated expression. Notable, novel DEGs among salinities and gill types for C. sapidus included anterior gills having higher expression of structural genes such as actin and cuticle proteins while posterior gills exhibit elevated expression of ion transport and energy-related genes, with the latter likely linked to ion transport. Potential targets among recovered DEGs for hormonal regulation of ion transport between salinities and gill types included neuropeptide Y and a KCTD16-like protein. Using publically available sequence data, constituents for a “core” gill transcriptome among decapods are presented, comprising genes involved in ion transport and energy conversion and consistent with salinity transfer experiments. Lastly, rarefication analyses lead us to recommend a modest number of sequence reads (~10–15 M), but with increased biological replication, be utilized in future DEG analyses of crustaceans. PMID:27337176

Biodegradation of the chitin-protein complex in crustacean cuticle

USGS Publications Warehouse

Artur, Stankiewicz B.; Mastalerz, Maria; Hof, C.H.J.; Bierstedt, A.; Flannery, M.B.; Briggs, D.E.G.; Evershed, R.P.

1998-01-01

Arthropod cuticles consist predominantly of chitin cross-linked with proteins. While there is some experimental evidence that this chitin-protein complex may resist decay, the chemical changes that occur during degradation have not been investigated in detail. The stomatopod crustacean Neogonodactylus oerstedii was decayed in the laboratory under anoxic conditions. A combination of pyrolysis-gas chromatography/mass spectrometry and FTIR revealed extensive chemical changes after just 2 weeks that resulted in a cuticle composition dominated by chitin. Quantitative analysis of amino acids (by HPLC) and chitin showed that the major loss of proteins and chitin occurred between weeks 1 and 2. After 8 weeks tyrosine, tryptophan and valine are the most prominent amino acid moieties, showing their resistance to degradation. The presence of cyclic ketones in the pyrolysates indicates that mucopolysaccharides or other bound non-chitinous carbohydrates are also resistant to decay. There is no evidence of structural degradation of chitin prior to 8 weeks when FTIR revealed a reduction in chitin-specific bands. The chemical changes are paralleled by structural changes in the cuticle, which becomes an increasingly open structure consisting of loose chitinous fibres. The rapid rate of decay in the experiments suggests that where chitin and protein are preserved in fossil cuticles degradation must have been inhibited.Arthropod cuticles consist predominantly of chitin cross-linked with proteins. While there is some experimental evidence that this chitin-protein complex may resist decay, the chemical changes that occur during degradation have not been investigated in detail. The stomatopod crustacean Neogonodactylus oerstedii was decayed in the laboratory under anoxic conditions. A combination of pyrolysis-gas chromatography/mass spectrometry and FTIR revealed extensive chemical changes after just 2 weeks that resulted in a cuticle composition dominated by chitin. Quantitative

Global Diversity of Marine Isopods (Except Asellota and Crustacean Symbionts)

PubMed Central

Poore, Gary C. B.; Bruce, Niel L.

2012-01-01

The crustacean order Isopoda (excluding Asellota, crustacean symbionts and freshwater taxa) comprise 3154 described marine species in 379 genera in 37 families according to the WoRMS catalogue. The history of taxonomic discovery over the last two centuries is reviewed. Although a well defined order with the Peracarida, their relationship to other orders is not yet resolved but systematics of the major subordinal taxa is relatively well understood. Isopods range in size from less than 1 mm to Bathynomus giganteus at 365 mm long. They inhabit all marine habitats down to 7280 m depth but with few doubtful exceptions species have restricted biogeographic and bathymetric ranges. Four feeding categories are recognised as much on the basis of anecdotal evidence as hard data: detritus feeders and browsers, carnivores, parasites, and filter feeders. Notable among these are the Cymothooidea that range from predators and scavengers to external blood-sucking micropredators and parasites. Isopods brood 10–1600 eggs depending on individual species. Strong sexual dimorphism is characteristic of several families, notably in Gnathiidae where sessile males live with a harem of females while juvenile praniza stages are ectoparasites of fish. Protandry is known in Cymothoidae and protogyny in Anthuroidea. Some Paranthuridae are neotenous. About half of all coastal, shelf and upper bathyal species have been recorded in the MEOW temperate realms, 40% in tropical regions and the remainder in polar seas. The greatest concentration of temperate species is in Australasia; more have been recorded from temperate North Pacific than the North Atlantic. Of tropical regions, the Central Indo-Pacific is home to more species any other region. Isopods are decidedly asymmetrical latitudinally with 1.35 times as many species in temperate Southern Hemisphere than the temperate North Atlantic and northern Pacific, and almost four times as many Antarctic as Arctic species. More species are known from

A New Chytridiomycete Fungus Intermixed with Crustacean Resting Eggs in a 407-Million-Year-Old Continental Freshwater Environment

PubMed Central

Goral, Tomasz; Longcore, Joyce E.; Olesen, Jørgen; Kenrick, Paul; Edgecombe, Gregory D.

2016-01-01

The 407-million-year-old Rhynie Chert (Scotland) contains the most intact fossilised remains of an early land-based ecosystem including plants, arthropods, fungi and other microorganisms. Although most studies have focused on the terrestrial component, fossilised freshwater environments provide critical insights into fungal-algal interactions and the earliest continental branchiopod crustaceans. Here we report interactions between an enigmatic organism and an exquisitely preserved fungus. The fungal reproductive structures are intermixed with exceptionally well-preserved globular spiny structures interpreted as branchiopod resting eggs. Confocal laser scanning microscopy enabled us to reconstruct the fungus and its possible mode of nutrition, the affinity of the resting eggs, and their spatial associations. The new fungus (Cultoraquaticus trewini gen. et sp. nov) is attributed to Chytridiomycota based on its size, consistent formation of papillae, and the presence of an internal rhizoidal system. It is the most pristine fossil Chytridiomycota known, especially in terms of rhizoidal development and closely resembles living species in the Rhizophydiales. The spiny resting eggs are attributed to the crustacean Lepidocaris rhyniensis, dating branchiopod adaptation to life in ephemeral pools to the Early Devonian. The new fungal interaction suggests that, as in modern freshwater environments, chytrids were important to the mobilisation of nutrients in early aquatic foodwebs. PMID:27973602

Role of cellular compartmentalization in the trophic transfer of mercury species in a freshwater plant-crustacean food chain.

PubMed

Beauvais-Flück, Rebecca; Chaumot, Arnaud; Gimbert, Frédéric; Quéau, Hervé; Geffard, Olivier; Slaveykova, Vera I; Cosio, Claudia

2016-12-15

Mercury (Hg) represents an important risk for human health through the food webs contamination. Macrophytes bioaccumulate Hg and play a role in Hg transfer to food webs in shallow aquatic ecosystems. Nevertheless, the compartmentalization of Hg within macrophytes, notably major accumulation in the cell wall and its impact on trophic transfer to primary consumers are overlooked. The present work focusses on the trophic transfer of inorganic Hg (IHg) and monomethyl-Hg (MMHg) from the intracellular and cell wall compartments of the macrophyte Elodea nuttallii - considered a good candidate for phytoremediation - to the crustacean Gammarus fossarum. The results demonstrated that Hg accumulated in both compartments was trophically bioavailable to gammarids. Besides IHg from both compartments were similarly transferred to G. fossarum, while for MMHg, uptake rates were ∼2.5-fold higher in G. fossarum fed with the cell wall vs the intracellular compartment. During the depuration phase, Hg concentrations in G. fossarum varied insignificantly suggesting that both IHg and MMHg were strongly bound to biological ligands in the crustacean. Our data imply that cell walls have to be considered as an important source of Hg to consumers in freshwater food webs when developing procedures for enhancing aquatic environment protection during phytoremediation programs. Copyright © 2016 Elsevier B.V. All rights reserved.

Alternative mitochondrial respiratory chains from two crustaceans: Artemia franciscana nauplii and the white shrimp, Litopenaeus vannamei.

PubMed

Rodriguez-Armenta, Chrystian; Uribe-Carvajal, Salvador; Rosas-Lemus, Monica; Chiquete-Felix, Natalia; Huerta-Ocampo, Jose Angel; Muhlia-Almazan, Adriana

2018-04-01

Mitochondrial ATP is synthesized by coupling between the electron transport chain and complex V. In contrast, physiological uncoupling of these processes allows mitochondria to consume oxygen at high rates without ATP synthesis. Such uncoupling mechanisms prevent reactive oxygen species overproduction. One of these mechanisms are the alternative redox enzymes from the mitochondrial respiratory chain, which may help cells to maintain homeostasis under stress independently of ATP synthesis. To date, no reports have been published on alternative redox enzymes in crustaceans mitochondria. Specific inhibitors were used to identify alternative redox enzymes in mitochondria isolated from Artemia franciscana nauplii, and the white shrimp, Litopenaeus vannamei. We report the presence of two alternative redox enzymes in the respiratory chain of A. franciscana nauplii, whose isolated mitochondria used glycerol-3-phosphate as a substrate, suggesting the existence of a glycerol-3-phosphate dehydrogenase. In addition, cyanide and octyl-gallate were necessary to fully inhibit this species' mitochondrial oxygen consumption, suggesting an alternative oxidase is present. The in-gel activity analysis confirmed that additional mitochondrial redox proteins exist in A. franciscana. A mitochondrial glycerol-3-phosphate dehydrogenase oxidase was identified by protein sequencing as part of a branched respiratory chain, and an alternative oxidase was also identified in this species by western blot. These results indicate different adaptive mechanisms from artemia to face environmental challenges related to the changing levels of oxygen concentration in seawater through their life cycles. No alternative redox enzymes were found in shrimp mitochondria, further efforts will determine the existence of an uncoupling mechanism such as uncoupling proteins.

Experimental whole-lake increase of dissolved organic carbon concentration produces unexpected increase in crustacean zooplankton density

USGS Publications Warehouse

Kelly, Patrick T.; Craig, Nicola; Solomon, Christopher T.; Weidel, Brian C.; Zwart, Jacob A.; Jones, Stuart E.

2016-01-01

The observed pattern of lake browning, or increased terrestrial dissolved organic carbon (DOC) concentration, across the northern hemisphere has amplified the importance of understanding how consumer productivity varies with DOC concentration. Results from comparative studies suggest these increased DOC concentrations may reduce crustacean zooplankton productivity due to reductions in resource quality and volume of suitable habitat. Although these spatial comparisons provide an expectation for the response of zooplankton productivity as DOC concentration increases, we still have an incomplete understanding of how zooplankton respond to temporal increases in DOC concentration within a single system. As such, we used a whole-lake manipulation, in which DOC concentration was increased from 8 to 11 mg L−1 in one basin of a manipulated lake, to test the hypothesis that crustacean zooplankton production should subsequently decrease. In contrast to the spatially derived expectation of sharp DOC-mediated decline, we observed a small increase in zooplankton densities in response to our experimental increase in DOC concentration of the treatment basin. This was due to significant increases in gross primary production and resource quality (lower seston carbon-to-phosphorus ratio; C:P). These results demonstrate that temporal changes in lake characteristics due to increased DOC may impact zooplankton in ways that differ from those observed in spatial surveys. We also identified significant interannual variability across our study region, which highlights potential difficulty in detecting temporal responses of organism abundances to gradual environmental change (e.g., browning).

The Genome Sizes of Ostracod Crustaceans Correlate with Body Size and Evolutionary History, but not Environment.

PubMed

Jeffery, Nicholas W; Ellis, Emily A; Oakley, Todd H; Gregory, T Ryan

2017-09-01

Within animals, a positive correlation between genome size and body size has been detected in several taxa but not in others, such that it remains unknown how pervasive this pattern may be. Here, we provide another example of a positive relationship in a group of crustaceans whose genome sizes have not previously been investigated. We analyze genome size estimates for 46 species across the 2 most diverse orders of Class Ostracoda, commonly known as seed shrimps, including 29 new estimates made using Feulgen image analysis densitometry and flow cytometry. Genome sizes in this group range ~80-fold, a level of variability that is otherwise not seen in crustaceans with the exception of some malacostracan orders. We find a strong positive correlation between genome size and body size across all species, including after phylogenetic correction. We additionally detect evidence of XX/XO sex determination in 3 species of marine ostracods where male and female genome sizes were estimated. On average, genome sizes are larger but less variable in Order Myodocopida than in Order Podocopida, and marine ostracods have larger genomes than freshwater species, but this appears to be explained by phylogenetic inertia. The relationship between phylogeny, genome size, body size, and habitat is complex in this system and provides a baseline for future studies examining the interactions of these biological traits. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Negative effects of Microcystis blooms on the crustacean plankton in an enclosure experiment in the subtropical China.

PubMed

Chen, Fei-zhou; Xie, Ping; Tang, Hui-juan; Liu, Hong

2005-01-01

Effects of Microcystis blooms on the crustacean plankton were studied using enclosure experiments during July-September, 2000. Eight enclosures were set in the hypereutrophic Donghu Lake. Different nutrient concentrations through additional nutrient and sediment in enclosures were expected to result in different abundance of Microcystis. From July to early August, the phytoplankton community was dominated by Chlorophyta, Cryptophyta, Bacillariophyta and Cyanophyta other than Microcystis aeruginosa. M. aeruginosa showed a rapid increase during early August in all enclosures and predominated. Crustacean plankton was dominated by the herbivorous Moina micrura, Diaphanosoma brachyurum and Ceriodaphnia cornuta, and the predaceous Mesocyclops sp. and Thermocyclops taihokuensis. During the pre-bloom period, the dynamics of M. micrura population appeared to be mainly affected by the predaceous cyclopoids. With the development of Microcystis blooms, such interaction between M. micrura and cyclopoids seemed weakened, especially when the Microcystis biomass was high. But there was no apparent influence on the interaction between Leptodora kindti and its zooplanktonic prey. The density of two cyclopoids decreased with the enhancement of Microcystis. The density decline of M. micrura was caused by both predation and inhibition by Microcystis. The low food availability of other edible phytoplankton during the blooms led to low densities of both C. cornuta and D. brachyurum by late August. It appears that dense Microcystis blooms exert strong negative effects on the herbivorous cladocerans and the predaceous cyclopoids.

`Akohekohe response to flower availability: seasonal abundance, foraging, breeding, and molt

USGS Publications Warehouse

Berlin, Kim E.; Simon, John C.; Pratt, T.K.; Kowalsky, James R.; Hatfield, J.S.; Scott, J.M.; Conant, S.; van Riper, Charles

2001-01-01

We studied the relationship of flower availability to the seasonality of life history events of the `Akohekohe (Palmeria dolei), a primarily nectarivorous and endangered Hawaiian honeycreeper from montane rain forests on Maui, Hawai`i. For comparison, we also investigated temporal bird density and foraging behavior of three other competing Hawaiian honeycreepers: `Apapane (Himatione sanguinea), `I`iwi (Vestiaria coccinea), and Hawai`i `Amakihi (Hemignathus virens). All species except `Amakihi fed primarily on nectar of `Ohi?a-lehua (Metrosideros polymorpha), which produced flowers year-round but had an annual flowering peak in January. Flowers of several subcanopy shrubs and trees were important components of the diet for all nectarivores, and these were available seasonally depending upon the species. `Akohekohe densities did not change temporally, suggesting a relatively stable population residing above 1,700 m. Monthly densities of `Apapane, `I`iwi, and Hawai`i `Amakihi were positively correlated with monthly `Ohi?a-lehua flower abundance, and 50-80% of these populations departed temporarily from our high-elevation site in July. There was a positive correlation with the timing of Akohekohe breeding and high abundance of `Ohi?a-lehua bloom. Molt followed breeding. From a conservation perspective, these results show that `Akohekohe maintain a relatively stable population above the mid-elevation zone of disease transmission, particularly during the fall when `Ohi?a-lehua bloom decreases and mosquitoes increase. `Akohekohe remain on their territories partly by switching their foraging to subcanopy trees and shrubs, most of which require protection from feral pigs (Sus scrofa).

The phylogeny and life cycle of two species of Profilicollis (Acanthocephala: Polymorphidae) in marine hosts off the Pacific coast of Chile.

PubMed

Rodríguez, S M; D'Elía, G; Valdivia, N

2017-09-01

Resolving complex life cycles of parasites is a major goal of parasitological research. The aim of this study was to analyse the life cycle of two species of the genus Profilicollis, the taxonomy of which is still unstable and life cycles unclear. We extracted individuals of Profilicollis from two species of crustaceans (intermediate hosts) and four species of seagulls (definitive hosts) from sandy-shore and estuarine habitats along the south-east Pacific coast of Chile. Mitochondrial DNA analyses showed that two species of Profilicollis infected intermediate hosts from segregated habitats: while P. altmani larvae infected exclusively molecrabs of the genus Emerita from fully marine habitats, P. antarcticus larvae infected the crab Hemigrapsus crenulatus from estuarine habitats. Moreover, P. altmani completed its life cycle in four seagulls, Chroicocephalus maculipennis, Leucopheus pipixcan, Larus modestus and L. dominicanus, while P. antarcticus, on the other hand, completed its life cycle in the kelp gull L. dominicanus. Accordingly, our results show that two congeneric parasites use different and spatially segregated species as intermediate hosts, and both are capable of infecting one species of definitive hosts. As such, our analyses allow us to shed light on a complex interaction network.

Replacement of a cytosolic copper/zinc superoxide dismutase by a novel cytosolic manganese superoxide dismutase in crustaceans that use copper (haemocyanin) for oxygen transport.

PubMed Central

Brouwer, Marius; Hoexum Brouwer, Thea; Grater, Walter; Brown-Peterson, Nancy

2003-01-01

The blue crab, Callinectes sapidus, which uses the copper-dependent protein haemocyanin for oxygen transport, lacks the ubiquitous cytosolic copper-dependent enzyme copper/zinc superoxide dismutase (Cu,ZnSOD) as evidenced by undetectable levels of Cu,ZnSOD activity, protein and mRNA in the hepatopancreas (the site of haemocyanin synthesis) and gills. Instead, the crab has an unusual cytosolic manganese SOD (cytMnSOD), which is retained in the cytosol, because it lacks a mitochondrial transit peptide. A second familiar MnSOD is present in the mitochondria (mtMnSOD). This unique phenomenon occurs in all Crustacea that use haemocyanin for oxygen transport. Molecular phylogeny analysis suggests the MnSOD gene duplication is as old as the origin of the arthropod phylum. cytMnSOD activity in the hepatopancreas changes during the moulting cycle of the crab. Activity is high in intermoult crabs and non-detectable in postmoult papershell crabs. mtMnSOD is present in all stages of the moulting cycle. Despite the lack of cytCu,ZnSOD, crabs have an extracellular Cu,ZnSOD (ecCu,ZnSOD) that is produced by haemocytes, and is part of a large, approx. 160 kDa, covalently-linked protein complex. ecCu,ZnSOD is absent from the hepatopancreas of intermoult crabs, but appears in this tissue at premoult. However, no ecCu,ZnSOD mRNA can be detected, suggesting that the protein is recruited from the haemolymph. Screening of different taxa of the arthropod phylum for Cu,ZnSOD activity shows that those crustaceans that use haemoglobin for oxygen transport have retained cytCu,ZnSOD. It appears, therefore, that the replacement of cytCu,ZnSOD with cytMnSOD is part of an adaptive response to the dynamic, haemocyanin-linked, fluctuations in copper metabolism that occur during the moulting cycle of the crab. PMID:12769817

The global diversity of parasitic isopods associated with crustacean hosts (Isopoda: Bopyroidea and Cryptoniscoidea).

PubMed

Williams, Jason D; Boyko, Christopher B

2012-01-01

Parasitic isopods of Bopyroidea and Cryptoniscoidea (commonly referred to as epicarideans) are unique in using crustaceans as both intermediate and definitive hosts. In total, 795 epicarideans are known, representing ~7.7% of described isopods. The rate of description of parasitic species has not matched that of free-living isopods and this disparity will likely continue due to the more cryptic nature of these parasites. Distribution patterns of epicarideans are influenced by a combination of their definitive (both benthic and pelagic species) and intermediate (pelagic copepod) host distributions, although host specificity is poorly known for most species. Among epicarideans, nearly all species in Bopyroidea are ectoparasitic on decapod hosts. Bopyrids are the most diverse taxon (605 species), with their highest diversity in the North West Pacific (139 species), East Asian Sea (120 species), and Central Indian Ocean (44 species). The diversity patterns of Cryptoniscoidea (99 species, endoparasites of a diverse assemblage of crustacean hosts) are distinct from bopyrids, with the greatest diversity of cryptoniscoids in the North East Atlantic (18 species) followed by the Antarctic, Mediterranean, and Arctic regions (13, 12, and 8 species, respectively). Dajidae (54 species, ectoparasites of shrimp, mysids, and euphausids) exhibits highest diversity in the Antarctic (7 species) with 14 species in the Arctic and North East Atlantic regions combined. Entoniscidae (37 species, endoparasites within anomuran, brachyuran and shrimp hosts) show highest diversity in the North West Pacific (10 species) and North East Atlantic (8 species). Most epicarideans are known from relatively shallow waters, although some bopyrids are known from depths below 4000 m. Lack of parasitic groups in certain geographic areas is likely a sampling artifact and we predict that the Central Indian Ocean and East Asian Sea (in particular, the Indo-Malay-Philippines Archipelago) hold a wealth of

The Global Diversity of Parasitic Isopods Associated with Crustacean Hosts (Isopoda: Bopyroidea and Cryptoniscoidea)

PubMed Central

Williams, Jason D.; Boyko, Christopher B.

2012-01-01

Parasitic isopods of Bopyroidea and Cryptoniscoidea (commonly referred to as epicarideans) are unique in using crustaceans as both intermediate and definitive hosts. In total, 795 epicarideans are known, representing ∼7.7% of described isopods. The rate of description of parasitic species has not matched that of free-living isopods and this disparity will likely continue due to the more cryptic nature of these parasites. Distribution patterns of epicarideans are influenced by a combination of their definitive (both benthic and pelagic species) and intermediate (pelagic copepod) host distributions, although host specificity is poorly known for most species. Among epicarideans, nearly all species in Bopyroidea are ectoparasitic on decapod hosts. Bopyrids are the most diverse taxon (605 species), with their highest diversity in the North West Pacific (139 species), East Asian Sea (120 species), and Central Indian Ocean (44 species). The diversity patterns of Cryptoniscoidea (99 species, endoparasites of a diverse assemblage of crustacean hosts) are distinct from bopyrids, with the greatest diversity of cryptoniscoids in the North East Atlantic (18 species) followed by the Antarctic, Mediterranean, and Arctic regions (13, 12, and 8 species, respectively). Dajidae (54 species, ectoparasites of shrimp, mysids, and euphausids) exhibits highest diversity in the Antarctic (7 species) with 14 species in the Arctic and North East Atlantic regions combined. Entoniscidae (37 species, endoparasites within anomuran, brachyuran and shrimp hosts) show highest diversity in the North West Pacific (10 species) and North East Atlantic (8 species). Most epicarideans are known from relatively shallow waters, although some bopyrids are known from depths below 4000 m. Lack of parasitic groups in certain geographic areas is likely a sampling artifact and we predict that the Central Indian Ocean and East Asian Sea (in particular, the Indo-Malay-Philippines Archipelago) hold a wealth of

A catalogue of the type and figured fossil decapod crustaceans in the collections of the Geological Survey of Austria in Vienna

PubMed Central

Hyžný, Matúš; Zorn, Irene

2017-01-01

The present catalogue lists and figures the type and figured material of fossil decapod crustaceans housed in the collections of the Geological Survey of Austria in Vienna. Specimens previously believed to be lost were relocated. Lectotypes and paralectotypes are chosen herein for 11 species. Taxonomic affinity of taxa originally described in open nomenclature is discussed. PMID:28255177

Ontogenetic adaptations in the visual systems of deep-sea crustaceans.

PubMed

Frank, Tamara M

2017-04-05

For all visually competent organisms, the driving force behind the adaptation of photoreceptors involves obtaining the best balance of resolution to sensitivity in the prevailing light regime, as an increase in sensitivity often results in a decrease in resolution. A number of marine species have an additional problem to deal with, in that the juvenile stages live in relatively brightly lit shallow (100-200 m depth) waters, whereas the adult stages have daytime depths of more than 600 m, where little downwelling light remains. Here, I present the results of electrophysiological analyses of the temporal resolution and irradiance sensitivity of juvenile and adult stages of two species of ontogenetically migrating crustaceans ( Gnathophausia ingens and Systellaspis debilis ) that must deal with dramatically different light environments and temperatures during their life histories. The results demonstrate that there are significant effects of temperature on temporal resolution, which help to optimize the visual systems of the two life-history stages for their respective light environments.This article is part of the themed issue 'Vision in dim light'. © 2017 The Author(s).

Monthly variation in crustacean assemblage (decapod and stomatopod) and its relationships with environmental variables in Laizhou Bay, China

NASA Astrophysics Data System (ADS)

Wu, Qiang; Wang, Jun; Zhang, Bo; Chen, Ruisheng; Jin, Xianshi

2016-04-01

In this study, we investigated the community structure of crustaceans (decapod and stomatopod) inhabiting the sandy mud bottoms of Laizhou Bay (northeastern China) monthly from May 2011 to April 2012. Investigation was stopped from December 2011 to February 2012 because of the extreme weather and sea ice. A total of 205,057 specimens belonging to 31 species (shrimp, 15; crab, 15; and stomatopod, 1) were collected in 148 hauls. From 2011 to 2012, Oratosquilla oratoria was the dominant biomass species (47.80%), followed by Charybdis japonica (15.49%), Alpheus japonicas (12.61%), Portunus trituberculatus (6.46%), and Crangon spp. (4.19%). Crangon spp. was the most dominant species by individual (32.55%). O. oratoria was the most-frequently encountered species (81.76%), followed by Palaemon gravieri (70.95%), C. japonica (65.54%), A. japonicas (62.16%), and P. trituberculatus (54.73%). The biomass density increased from August to September 2011 and decreased from March 2012 to April 2012. The dynamics of the ecological indices evolve in a similar manner, with high values of diversity and evenness and rich species from May to June 2011 and low values from September to October 2011. O. oratoria, C. japonica, and P. trituberculatus differed by biomass data between groups I (samples obtained from September to October 2011) and II (samples in other months). These species contributed more than 70% to the similarity of the crustacean community structure. Furthermore, the subsets of environmental variables that best matched the crustacean-assemblage structure were as follows: water depth (WD) in summer (June to August); sea surface temperature (SST), dissolved oxygen (DO), and WD in autumn (September to November); and DO, salinity, and WD in spring (March to May). The calculated correlation coefficients and significance level were higher in the period of July to August 2011 than in other months. Comparing 2011 to 2012 with 1982 to 1983, the species composition remained stable

Visualization of ecdysteroid activity using a reporter gene in the crustacean, Daphnia.

PubMed

Asada, Miki; Kato, Yasuhiko; Matsuura, Tomoaki; Watanabe, Hajime

2014-02-01

Ecdysone is a hormone known to play a pivotal role in crustaceans and insects. In order to evaluate the ecdysone activities in the environment and within the organism, we have developed a biomonitoring Daphnia strain by introducing a reporter gene. In this study, the ecdysone response element was inserted in the upstream region of a reporter gene, and the DNA construct was injected into Daphnia eggs. The expression of the reporter gene was detected during the early embryonic development stage. In addition, when the eggs expressing the reporter gene were exposed to ecdysone, there was enhanced expression of the reporter gene at detectable levels, while the presence of an antagonist led to its downregulation. These results suggested that this system could be potentially developed for monitoring ecdysone activities in media. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of near-bottom environmental conditions on the structure of bathyal macrobenthic crustacean assemblages from the Capbreton canyon (Bay of Biscay, NE Atlantic)

NASA Astrophysics Data System (ADS)

Marquiegui, Mikel A.; Sorbe, Jean Claude

1999-07-01

Sled and box-corer samplings were performed at two sites in the Capbreton canyon in order to appreciate the influence of near-bottom environmental conditions on the structure of their macrobenthic communities (crustaceans). Although located at similar depths (ca. 1 000 m), these two sites were characterised by different physicochemical conditions at the sediment-water interface, probably related with the morphology of the submarine valley (reduced environment, oxygen depletion and stagnation of bottom water at site A; normal oceanic conditions on the near-bottom environment of site B). The analysis of the collected fauna revealed a low similarity between the two sites, mainly due to the unusual dominance of three epibenthic species in sled samples from site A: the amphipod Bonnierella abyssorum, the tanaid Apseudes spinosus and the isopod Arcturopsis giardi. Due to their apparent rarity or absence in adjacent non-canyon communities, such epibenthic crustaceans may be considered as `canyon indicator species' able to exhibit abundant populations within the peculiar confinement area of this canyon.

[Localization of crustaceans--fish parasites and nose capsules as the habitat of the genus Salmincola (Podoplea: Lernaeopodidae) mesoparasites].

PubMed

Pronin, N M; Burdukovskaia, T G

2013-01-01

Copepoda parasitica of Baikal fishes (16 species) is divided into 7 groups according to their localization: parasites of the gill apparatus, gill covers, gill and buccal cavities, nasal fossa, cutaneous covering, and fins. It was proposed to separate nasal fossa parasites as the special ecological group ofmesoparasites. Typical speciemens of the group include crustaceans Salmincola longimanus complex--parasites of grayling and cisco fishes consist of three species (S. longimanus, S. svetlanovi, S. lavaretus) and one subspecies (S. longimanus sibirica).

Urnaloricus gadi nov. gen. et nov. sp. (Loricifera, Urnaloricidae nov. fam.), an aberrant Loricifera with a viviparous pedogenetic life cycle.

PubMed

Heiner, Iben; Kristensen, Reinhardt Møbjerg

2009-02-01

A new species of Loricifera, Urnaloricus gadi nov. gen. et nov. sp., is described from the Faroe Bank, located Southwest of the Faroe Islands, North Atlantic. The new species does not fit into any known families of Loricifera and therefore it is grouped into a new family Urnaloricidae nov. fam. The new species is characterized by having a very complicated life cycle that involves a large cyst-like mega-larva, two reduced larval instars and the Higgins-larvae eating their maternal stage from within. An adult stage is missing. This form of reproduction is called viviparous pedogenesis and normally is found only in nematodes and insects. In the life cycle of Urnaloricidae nov. fam., there are two types of free-living larval stages: a Higgins-larva and a mega-larva. The latter is found in two different forms, a pre- and a cyst-forming mega-larva. Additionally, there are two reduced life history stages, the reduced larval stage (probably a postlarva) and the ghost-larval stage inside the cyst-forming mega-larva. The external morphology of the two forms of mega-larvae is much reduced, e.g., the introvert has only a few rows of scalids when compared with the Higgins-larva. The pre mega-larva is free-living and can sometimes be covered with coccoliths. Internally, a large ovary with a few oocytes, a digestive system, and an internal armature with retracted scalids are present. The pre mega-larva presumably molts into a cyst-forming mega-larva and thereby the ovary is now seen inside the cyst-forming mega-larva. The cyst-forming mega-larva has the same structures as in the pre mega-larva though here the scalids are protruded and there is a gonopore. Inside the cyst-forming mega-larva the ovary produces more oocytes and begins to fill out the entire lumen. At this stage the cyst-forming mega-larva molts first to the presumed postlarval stage, and then this stage molts to a ghost-larva. Hence, the ovary now matures inside the ghost-larva, which is surrounded by both the

gp160 of HIV-I synthesized by persistently infected Molt-3 cells is terminally glycosylated: evidence that cleavage of gp160 occurs subsequent to oligosaccharide processing.

PubMed

Merkle, R K; Helland, D E; Welles, J L; Shilatifard, A; Haseltine, W A; Cummings, R D

1991-10-01

The envelope glycoprotein of HIV-I in infected, cultured human T cells is synthesized as a precursor of apparent Mr 160 kDa (gp160) and is cleaved to two glycoproteins, gp120 and gp41, which are the mature envelope glycoproteins in the virus. Neither the temporal and spatial features of glycosylation nor the oligosaccharide processing and proteolytic cleavage of the envelope glycoprotein are well understood. To understand more about these events, we investigated the glycosylation and cleavage of the envelope glycoproteins in the CD4+ human cell line, Molt-3, persistently infected with HIV-I (HTLV IIIB). The carbohydrate analysis of gp160 and gp120 and the behavior of the glycoproteins and glycopeptides derived from them on immobilized lectins demonstrate that both of these glycoproteins contain complex- and high-mannose-type Asn-linked oligosaccharides. In addition, the N-glycanase-resistant oligosaccharides of gp120 were found to contain N-acetyl-galactosamine, a common constituent of Ser/Thr-linked oligosaccharides. Pulse-chase analysis of the conversion of [35S]cysteine-labeled gp160 showed that in Molt-3 cells it takes about 2 h for gp120 to arise with a half-time of conversion of about 5 h. At its earliest detectable occurrence, gp120 was found to contain complex-type Asn-linked oligosaccharides. Taken together, these results indicate that proteolytic cleavage of gp160 to gp120 and gp41 occurs either within the trans-Golgi or in a distal compartment.

The First Venomous Crustacean Revealed by Transcriptomics and Functional Morphology: Remipede Venom Glands Express a Unique Toxin Cocktail Dominated by Enzymes and a Neurotoxin

PubMed Central

von Reumont, Björn M.; Blanke, Alexander; Richter, Sandy; Alvarez, Fernando; Bleidorn, Christoph; Jenner, Ronald A.

2014-01-01

Animal venoms have evolved many times. Venomous species are especially common in three of the four main groups of arthropods (Chelicerata, Myriapoda, and Hexapoda), which together represent tens of thousands of species of venomous spiders, scorpions, centipedes, and hymenopterans. Surprisingly, despite their great diversity of body plans, there is no unambiguous evidence that any crustacean is venomous. We provide the first conclusive evidence that the aquatic, blind, and cave-dwelling remipede crustaceans are venomous and that venoms evolved in all four major arthropod groups. We produced a three-dimensional reconstruction of the venom delivery apparatus of the remipede Speleonectes tulumensis, showing that remipedes can inject venom in a controlled manner. A transcriptomic profile of its venom glands shows that they express a unique cocktail of transcripts coding for known venom toxins, including a diversity of enzymes and a probable paralytic neurotoxin very similar to one described from spider venom. We screened a transcriptomic library obtained from whole animals and identified a nontoxin paralog of the remipede neurotoxin that is not expressed in the venom glands. This allowed us to reconstruct its probable evolutionary origin and underlines the importance of incorporating data derived from nonvenom gland tissue to elucidate the evolution of candidate venom proteins. This first glimpse into the venom of a crustacean and primitively aquatic arthropod reveals conspicuous differences from the venoms of other predatory arthropods such as centipedes, scorpions, and spiders and contributes valuable information for ultimately disentangling the many factors shaping the biology and evolution of venoms and venomous species. PMID:24132120

Skin transcriptome reveals the intrinsic molecular mechanisms underlying hair follicle cycling in Cashmere goats under natural and shortened photoperiod conditions.

PubMed

Yang, Min; Song, Shen; Dong, Kunzhe; Chen, XiaoFei; Liu, Xuexue; Rouzi, Marhaba; Zhao, Qianjun; He, Xiaohong; Pu, Yabin; Guan, Weijun; Ma, Yuehui; Jiang, Lin

2017-10-18

The growth of cashmere exhibits a seasonal pattern arising from photoperiod change. However, the underlying molecular mechanism remains unclear. We profiled the skin transcriptome of six goats at seven time points during hair follicle cycling via RNA-seq. The six goats comprised three goats exposed to a natural photoperiod and three exposed to a shortened photoperiod. During hair cycle transition, 1713 genes showed differential expression, and 332 genes showed a pattern of periodic expression. Moreover, a short photoperiod induced the hair follicle to enter anagen early, and 246 genes overlapped with the periodic genes. Among these key genes, cold-shock domain containing C2 (CSDC2) was highly expressed in the epidermis and dermis of Cashmere goat skin, although its function in hair-follicle development remains unknown. CSDC2 silencing in mouse fibroblasts resulted in the decreased mRNA expression of two key hair-follicle factors, leading to reduced cell numbers and a lower cell density. Cashmere growth or molting might be controlled by a set of periodic regulatory genes. The appropriate management of short light exposure can induce hair follicles to enter full anagen early through the activation of these regulators. The CSDC2 gene is a potentially important transcription factor in the hair growth cycle.

Silent calcium channels in skeletal muscle fibers of the crustacean Atya lanipes.

PubMed

Monterrubio, J; Lizardi, L; Zuazaga, C

2000-01-01

The superficial (tonic) abdominal flexor muscles of Atya lanipes do not generate Ca(2+) action potentials when depolarized and have no detectable inward Ca(2+) current. These fibers, however, are strictly dependent on Ca(2+) influx for contraction, suggesting that they depend on Ca(2+)-induced Ca(2+) release for contractile activation. The nature of the communication between Ca(2+) channels in the sarcolemmal/tubular membrane and Ca(2+) release channels in the sarcoplasmic reticulum in this crustacean muscle was investigated. The effects of dihydropyridines on tension generation and the passive electrical response were examined in current-clamped fibers: Bay K 8644 enhanced tension about 100% but did not alter the passive electrical response; nifedipine inhibited tension by about 70%. Sr(2+) and Ba(2+) action potentials could be elicited in Ca(2+)-free solutions. The spikes generated by these divalent cations were abolished by nifedipine. As the Sr(2+) or Ba(2+) concentrations were increased, the amplitudes of the action potentials and their maximum rate of rise, V(max), increased and tended towards saturation. Three-microelectrode voltage-clamp experiments showed that even at high (138 mm) extracellular Ca(2+) concentration the channels were silent, i.e., no inward Ca(2+) current was detected. In Ca(2+)-free solutions, inward currents carried by 138 mm Sr(2+) or Ba(2+) were observed. The currents activated at voltages above -40 mV and peaked at about 0 mV. This voltage-activation profile and the sensitivity of the channels to dihydropyridines indicate that they resemble L-type Ca(2+) channels. Peak inward current density values were low, ca. -33 microA/cm(2) for Sr(2+) and -14 microA/cm(2) for Ba(2+), suggesting that Ca(2+) channels are present at a very low density. It is concluded that Ca(2+)-induced Ca(2+) release in this crustacean muscle operates with an unusually high gain: Ca(2+) influx through the silent Ca(2+) channels is too low to generate a macroscopic

A compilation of quantitative functional traits for marine and freshwater crustacean zooplankton.

PubMed

Hébert, Marie-Pier; Beisner, Beatrix E; Maranger, Roxane

2016-04-01

This data compilation synthesizes 8609 individual observations and ranges of 13 traits from 201 freshwater and 191 marine crustacean taxa belonging to either Copepoda or Cladocera, two important zooplankton groups across all major aquatic habitats. Most data were gathered from the literature, with the balance being provided by zooplankton ecologists. With the aim of more fully assessing zooplankton effects on elemental processes such as nitrogen (N), phosphorus (P) and carbon (C) stocks and fluxes in aquatic ecosystems, this data set provides information on the following traits: body size (length and mass), trophic group, elemental and biochemical corporal composition (N, P, C, lipid and protein content), respiration rates, N- and P-excretion rates, as well as stoichiometric ratios. Although relationships for zooplankton metabolism as a function of body mass or requirements have been explored in the past three decades, data have not been systematically compiled nor examined from an integrative and large-scale perspective across crustacean taxa and habitat types. While this contribution likely represents the most comprehensive assembly of traits for both marine and freshwater species, this data set is not exhaustive either. As a result, this compilation also identifies knowledge gaps: a fact that should encourage researchers to disclose information they may have to help complete such databases. This trait matrix is made available for the first time in this data paper; prior to its release, the data set has been analyzed in a meta-analysis published as a companion paper. This data set should prove extremely valuable for aquatic ecologists for trait-based characterization of plankton community structure as well as biogeochemical modeling. These data are also well-suited for deriving shortcut relationships that predict more difficult to measure trait values, most of which can be directly related to ecosystem properties (i.e., effect traits), from simpler traits (e

Cloning of precursors for two MIH/VIH-related peptides in the prawn, Macrobrachium rosenbergii.

PubMed

Yang, W J; Rao, K R

2001-11-30

Two cDNA clones (634 and 1366 bp) encoding MIH/VIH (molt-inhibiting hormone/vitellogenesis-inhibiting hormone)-related peptides were isolated and sequenced from a Macrobrachium rosenbergii eyestalk ganglia cDNA library. The clones contain a 360 and 339 bp open-reading frame, and their conceptually translated peptides consist of a 41 and 34 amino acid signal peptide, respectively, and a 78 amino acid residue mature peptide hormone. The amino acid sequences of the peptides exhibit higher identities with other known MIHs and VIH (44-69%) than with CHHs (28-33%). This is the first report describing the cloning and sequencing of two MIH/VIH-related peptides in a single crustacean species. Transcription of these mRNAs was detected in the eyestalk ganglia, but not in the thoracic ganglia, hepatopancreas, gut, gill, heart, or muscle.

Effects of latitudinal changes in the oxygen minimum zone of the northeast Pacific on the distribution of bathyal benthic decapod crustaceans

NASA Astrophysics Data System (ADS)

Papiol, Vanesa; Hendrickx, Michel E.; Serrano, David

2017-03-01

The presence of an Oxygen Minimum Zone (OMZ) is one of the major characteristics of the eastern Pacific. The OMZ changes strongly adjacent to Mexico in its thickness and intensity. The ecological impacts of those changes were studied by examining the community structures of bathyal benthic and bentho-pelagic decapod crustaceans, and their oceanographic contexts, on the Mexican Pacific slope along a wide latitudinal range (16-32°N). Decapod crustaceans were collected with a benthic sledge from 48 stations between 865 and 2165 m in three main areas: offshore of northern Baja California (NBC), off southern Baja California (SBC) and in the southern Mexican Pacific (SMP). Physical-chemical parameters were measured in the water column, and sediment composition was analyzed for each station. The narrowing and weakening of the OMZ north of ca. 26°N was confirmed. Water with dissolved oxygen <0.5 ml l-1 occupied a stratum of 1231 m in the SMP vs. only 664 m off NBC. The strongest changes coincided with a region of surface, subsurface and intermediate water mass transitions, where less saline waters from the north extended to depths of ca. 1000 m. Sand proportions were higher in sediments to the south, whereas silt dominated offshore of NBC. A strong latitudinal shift in decapod community composition and bathymetric distribution occurred from off SBC to off NBC, coinciding with changes in oceanographic conditions. The dominant genera of decapod crustaceans at slope depths were cognate to those dominating slope areas in other tropical and subtropical regions of the world. In the SMP and off SBC, large aggregations of organisms were observed at 900-1300 m, with a sharp decrease in abundance at greater depth. Off NBC, the density of organisms was intermediate at all depths. The combined effects of dissolved oxygen concentration and characteristics of water masses affected the distribution of organisms. The faunal patterns were also related with sediment grain size.

Evolution and development in cave animals: from fish to crustaceans.

PubMed

Protas, Meredith; Jeffery, William R

2012-01-01

Cave animals are excellent models to study the general principles of evolution as well as the mechanisms of adaptation to a novel environment: the perpetual darkness of caves. In this article, two of the major model systems used to study the evolution and development (evo-devo) of cave animals are described: the teleost fish Astyanax mexicanus and the isopod crustacean Asellus aquaticus. The ways in which these animals match the major attributes expected of an evo-devo cave animal model system are described. For both species, we enumerate the regressive and constructive troglomorphic traits that have evolved during their adaptation to cave life, the developmental and genetic basis of these traits, the possible evolutionary forces responsible for them, and potential new areas in which these model systems could be used for further exploration of the evolution of cave animals. Furthermore, we compare the two model cave animals to investigate the mechanisms of troglomorphic evolution. Finally, we propose a few other cave animal systems that would be suitable for development as additional models to obtain a more comprehensive understanding of the developmental and genetic mechanisms involved in troglomorphic evolution.

Population bottlenecks during the infectious cycle of the Lyme disease spirochete Borrelia burgdorferi.

PubMed

Rego, Ryan O M; Bestor, Aaron; Stefka, Jan; Rosa, Patricia A

2014-01-01

Borrelia burgdorferi is a zoonotic pathogen whose maintenance in nature depends upon an infectious cycle that alternates between a tick vector and mammalian hosts. Lyme disease in humans results from transmission of B. burgdorferi by the bite of an infected tick. The population dynamics of B. burgdorferi throughout its natural infectious cycle are not well understood. We addressed this topic by assessing the colonization, dissemination and persistence of B. burgdorferi within and between the disparate mammalian and tick environments. To follow bacterial populations during infection, we generated seven isogenic but distinguishable B. burgdorferi clones, each with a unique sequence tag. These tags resulted in no phenotypic changes relative to wild type organisms, yet permitted highly sensitive and specific detection of individual clones by PCR. We followed the composition of the spirochete population throughout an experimental infectious cycle that was initiated with a mixed inoculum of all clones. We observed heterogeneity in the spirochete population disseminating within mice at very early time points, but all clones displayed the ability to colonize most mouse tissues by 3 weeks of infection. The complexity of clones subsequently declined as murine infection persisted. Larval ticks typically acquired a reduced and variable number of clones relative to what was present in infected mice at the time of tick feeding, and maintained the same spirochete population through the molt to nymphs. However, only a random subset of infectious spirochetes was transmitted to naïve mice when these ticks next fed. Our results clearly demonstrate that the spirochete population experiences stochastic bottlenecks during both acquisition and transmission by the tick vector, as well as during persistent infection of its murine host. The experimental system that we have developed can be used to further explore the forces that shape the population of this vector-borne bacterial pathogen

Histological characterization of peppermint shrimp ( Lysmata wurdemanni) androgenic gland

NASA Astrophysics Data System (ADS)

Liu, Xin; Zhang, Dong; Lin, Tingting

2017-12-01

The androgenic gland (AG) is an important endocrine gland for male reproductive function in crustaceans. In the present study, we investigated the histological characteristics of the androgenic gland of peppermint shrimp, Lysmata wurdemanni. The peppermint shrimp matures as male first, then some individuals may become euhermaphrodite after several moltings (transitional phase). Euhermaphrodite-phase shrimp acts as male at intermolts. However, it can be fertilized as a female immediately after molting. Considering the male reproductive function acts in its lifespan except for at larval stages, and female reproductive system starts to develop at transitional phase, we hypothesized that AG activity might be reduced to allow and promote vitellogenesis onset in early transitional phase and the following euhermaphrodite phase. So AG cell structure might be different in three phases in L. wurdemanni. The results showed that AG exists in the male in transitional and euhermaphrodite phases. The gland cell clusters surrounding the ejaculatory ducts locate at the roots of the fifth pereopods. The nucleus diameters are similar in the three phases while the nucleus- to-cell ratio is the lowest in euhermaphrodite phase. Our results indicated that for the individuals that will become euhermaphrodite, the cellular structure of AG changes since transitional phase. Male reproductive function which is still available in euhermaphrodite-phase shrimp should be due to the existence of the gland.

The ecdysone receptor (EcR) is a major regulator of tissue development and growth in the marine salmonid ectoparasite, Lepeophtheirus salmonis (Copepoda, Caligidae).

PubMed

Sandlund, Liv; Nilsen, Frank; Male, Rune; Dalvin, Sussie

2016-08-01

The function of the ecdysone receptor (EcR) during development and molting has been thoroughly investigated in some arthropods such as insects but rarely in crustacean copepods such as the salmon louse Lepeophtheirus salmonis (L. salmonis) (Copepoda, Caligidae). The salmon louse is an ectoparasite on Atlantic salmon that has major economical impact in aquaculture due to the cost of medical treatment methods to remove lice from the fish. Handling of salmon louse infestations is further complicated by development of resistance towards available medicines. Understanding of basic molecular biological processes in the salmon louse is essential to enable development of new tools to control the parasite. In this study, we found L. salmonis EcR (LsEcR) transcript to be present in the neuronal somata of the brain, nuclei of muscle fibres and the immature intestine of the salmon louse. Furthermore, we explored the function of LsEcR during development using RNA interference mediated knock-down and through infection trials. Our results show that knock-down of LsEcR in the salmon louse is associated with hypotrophy of several tissues, delayed development and mortality. In addition, combined knock-down of LsEcR/LsRXR resulted in molting arrest during early larval stages. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Control of annual reproductive cycle in the subtropical house sparrow (Passer domesticus): evidence for conservation of photoperiodic control mechanisms in birds

PubMed Central

Trivedi, Amit K; Rani, Sangeeta; Kumar, Vinod

2006-01-01

Background In many birds, day length (=photoperiod) regulates reproductive cycle. The photoperiodic environment varies between different seasons and latitudes. As a consequence, species at different latitudes may have evolved separate photoperiodic strategies or modified them as per their adaptive need. We studied this using house sparrow as a model since it is found worldwide and is widely investigated. In particular, we examined whether photoperiodism in house sparrows (Passer domesticus) at 27°N, 81°E shared features with those exhibited by its conspecifics at high latitudes. Results Initial experiment described in the wild and captive conditions the gonad development and molt (only in captives) cycles over a 12-month period. Both male and female sparrows had similar seasonal cycles, linked with annual variations in day length; this suggested that seasonal reproduction in house sparrows was under the photoperiodic control. However, a slower testis and attenuated follicular growth among captives indicated that other (supplementary) factors are also involved in controlling the reproductive cycle. Next experiment examined if sparrows underwent seasonal variations in their response to stimulatory effects of long day lengths. When birds were transferred every month over a period of 1 year to 16 hours light:8 hours darkness (16L:8D) for 17–26 weeks, there was indeed a time-of-year effect on the growth-regression cycle of gonads. The final experiment investigated response of house sparrows to a variety of light-dark (LD) cycles. In the first set, sparrows were exposed for 31 weeks to photoperiods that were close to what they receive in between the period from sunrise to sunset at this latitude: 9L:15D (close to shortest day length in December), 12L:12D (equinox, in March and September) 15L:9D (close to longest day length in June). They underwent testicular growth and regression and molt in 12L and 15L photoperiods, but not in 9L photoperiod. In the second set

DNA replication events during larval silk gland development in the silkworm, Bombyx mori.

PubMed

Zhang, Chun-Dong; Li, Fang-Fang; Chen, Xiang-Yun; Huang, Mao-Hua; Zhang, Jun; Cui, Hongjuan; Pan, Min-Hui; Lu, Cheng

2012-07-01

The silk gland is an important organ in silkworm as it synthesizes silk proteins and is critical to spinning. The genomic DNA content of silk gland cells dramatically increases 200-400 thousand times for the larval life span through the process of endomitosis. Using in vitro culture, DNA synthesis was measured using BrdU labeling during the larval molt and intermolt periods. We found that the cell cycle of endomitosis was activated during the intermolt and was inhibited during the molt phase. The anterior silk gland, middle silk gland, and posterior silk gland cells asynchronously exit the endomitotic cycle after day 6 in 5th instar larvae, which correlated with the reduced expression of the cell cycle-related cdt1, pcna, cyclin E, cdk2 and cdk1 mRNAs in the wandering phase. Additional starvation had no effect on the initiation of silk gland DNA synthesis of the freshly ecdysed larvae. Copyright © 2012 Elsevier Ltd. All rights reserved.

Annotated checklist of the decapod crustaceans of the Gulf of Oman, northwestern Indian Ocean.

PubMed

Naderloo, Reza; Ebrahimnezhad, Saeed; Sari, Alireza

2015-10-09

The decapod crustaceans of the Gulf of Oman have been documented based on the published literature and new sampling along the Iranian coast between 2005 and 2015. A total of 121 species were collected along the Iranian coast, of which 43 are new records for the Gulf of Oman. The Decapoda of the Gulf is currently represented by 258 species belonging to five infraorders: Axiidea, Achelata, Anomura, Brachyura, and Caridea. Brachyura, with 176 species, are the best represented group, followed by Anomura and Caridea with 42 and 17 species, respectively. The least diverse groups are Achelata, with five species, and Axiidea, with three. On the basis of the available information, the northern (Iranian) coast with 189 species is more diverse than the southern (United Arab Emirates and Oman) coast with 134 species.

Prediction of Scylla olivacea (Crustacea; Brachyura) peptide hormones using publicly accessible transcriptome shotgun assembly (TSA) sequences.

PubMed

Christie, Andrew E

2016-05-01

The aquaculture of crabs from the genus Scylla is of increasing economic importance for many Southeast Asian countries. Expansion of Scylla farming has led to increased efforts to understand the physiology and behavior of these crabs, and as such, there are growing molecular resources for them. Here, publicly accessible Scylla olivacea transcriptomic data were mined for putative peptide-encoding transcripts; the proteins deduced from the identified sequences were then used to predict the structures of mature peptide hormones. Forty-nine pre/preprohormone-encoding transcripts were identified, allowing for the prediction of 187 distinct mature peptides. The identified peptides included isoforms of adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin B, allatostatin C, bursicon β, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone/molt-inhibiting hormone, diuretic hormone 31, eclosion hormone, FMRFamide-like peptide, HIGSLYRamide, insulin-like peptide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, pyrokinin, red pigment concentrating hormone, RYamide, short neuropeptide F, SIFamide and tachykinin-related peptide, all well-known neuropeptide families. Surprisingly, the tissue used to generate the transcriptome mined here is reported to be testis. Whether or not the testis samples had neural contamination is unknown. However, if the peptides are truly produced by this reproductive organ, it could have far reaching consequences for the study of crustacean endocrinology, particularly in the area of reproductive control. Regardless, this peptidome is the largest thus far predicted for any brachyuran (true crab) species, and will serve as a foundation for future studies of peptidergic control in members of the commercially important genus Scylla. Copyright © 2016 Elsevier Inc. All rights reserved.

Neuroendocrine regulation of osmoregulation and the evolution of air-breathing in decapod crustaceans.

PubMed

Morris, S

2001-03-01

Gills are the primary organ for salt transport, but in land crabs they are removed from water and thus ion exchanges, as well as CO(2) and ammonia excretion, are compromised. Urinary salt loss is minimised in land crabs by redirecting the urine across the gills where salt reabsorption occurs. Euryhaline marine crabs utilise apical membrane branchial Na(+)/H(+) and Cl(-)/HCO(3)(-) exchange powered by a basal membrane Na(+)/K(+)-ATPase, but in freshwater crustaceans an apical V-ATPase provides for electrogenic uptake of Cl(-) in exchange for HCO(3)(-). The HCO(3)(-) is provided by carbonic anhydrase facilitating CO(2) excretion while NH(4)(+) can substitute for K(+) in the basal ATPase and for H(+) in the apical exchange. Gecarcinid land crabs and the terrestrial anomuran Birgus latro can lower the NaCl concentration of the urine to 5 % of that of the haemolymph as it passes across the gills. This provides a filtration-reabsorption system analogous to the vertebrate kidney. Crabs exercise hormonal control over branchial transport processes. Aquatic hyper-regulators release neuroamines from the pericardial organs, including dopamine and 5-hydroxytryptamine (5-HT), which via a cAMP-mediated phosphorylation stimulate Na(+)/K(+)-ATPase activity and NaCl uptake. Freshwater species utilise a V-ATPase, and additional mechanisms of control have been suggested. Crustacean hyperglycaemic hormone (CHH) has now also been confirmed to have effects on hydromineral regulation, and a putative role for neuropeptides in salt and water balance suggests that current models for salt regulation are probably incomplete. In a terrestrial crabs there may be controls on both active uptake and diffusive loss. The land crab Gecarcoidea natalis drinking saline water for 3 weeks reduced net branchial Na(+) uptake but not Na(+)/K(+)-ATPase activity, thus implying a reduction in diffusive Na(+) loss. Further, in G. natalis Na(+) uptake and Na(+)/K(+)-ATPase were stimulated by 5-HT independently of

Life cycle and molecular phylogeny of the dinoflagellates Chytriodinium and Dissodinium, ectoparasites of copepod eggs.

PubMed

Gómez, Fernando; Moreira, David; López-García, Purificación

2009-11-01

The dinoflagellates Chytriodinium affine, C. roseum and Dissodinium pseudolunula are ectoparasites of crustacean eggs. Here, we present new observations regarding their life cycle based on coastal plankton samples and incubations and analyze their molecular phylogeny using the small subunit ribosomal RNA gene (SSU rDNA) as a marker. In contrast to the typical stages already documented for its life cycle, we observed that D. pseudolunula dinospores may exceptionally differentiate inside a globular cyst. Despite its parasitic life style, the cysts and dinospores of D. pseudolunula contain chlorophyll a. We obtained the first SSU rDNA sequences for the genera Chytriodinium (the type C. roseum and C. affine) and Dissodinium (D. pseudolunula). Classical taxonomical schemes have ascribed these genera to the order Blastodiniales. However, our SSU rDNA-based phylogenetic analysis shows that these ectoparasites form a clade in the Gymnodinium sensu stricto group, unarmored dinokaryotic dinoflagellates of the order Gymnodiniales. They branch in a subgroup composed of warnowiids, polykrikoids, the type of Gymnodinium, G. fuscum and G. aureolum. Although Chytriodinium and Dissodinium appear to be relatives based on SSU rDNA phylogeny, feeding and host specificity, their life cycles are substantially different. Based on these data we consider that the type of life cycle is a poor criterion for classification at the family level. We suggest that the morphology of the infective cell is probably the most reliable phenotypic characteristic to determine the systematic position of parasitic dinoflagellates.

Characterizing diurnal and seasonal cycles in monsoon systems from TRMM and CEOP observations

NASA Technical Reports Server (NTRS)

Lau, William K. M.

2006-01-01

The CEOP Inter-Monsoon Study (CIMS) is one of the two main science drivers of CEOP that aims to (a) provide better understanding of fundamental physical processes in monsoon regions around the world, and (b) demonstrate the synergy and utility of CEOP data in providing a pathway for model physics evaluation and improvement. As the data collection phase for EOP-3 and EOP-4 is being completed, two full annual cycles (2003-2004) of research-quality data sets from satellites, reference sites, and model output location time series (MOLTS) have been processed and made available for data analyses and model validation studies. This article presents preliminary results of a CIMS study aimed at the characterization and intercomparison of all major monsoon systems. The CEOP reference site data proved its value in such exercises by being a powerful tool to cross-validate the TRMM data, and to intercompare with multi-model results in ongoing work. We use 6 years (1998-2003) of pentad CEOP/TRMM data with 2deg x 2.5deg latitude-longitude grid, over the domain of interests to define the monsoon climatological diurnal and annual cycles for the East Asian Monsoon (EAM), the South Asian Monsoon (SAM), the West Africa Monsoon (WAM), the North America/Mexican Monsoon (NAM), the South American Summer Monsoon (SASM) and the Australian Monsoon (AUM). As noted, the TRMM data used in the study were cross-validated using CEOP reference site data, where applicable. Results show that the observed diurnal cycle of rain peaked around late afternoon over monsoon land, and early morning over the oceans. The diurnal cycles in models tend to peak 2-3 hours earlier than observed. The seasonal cycles of the EAM and SAM show the strongest continentality, i.e, strong control by continental processes away from the ITCZ. The WAM, and the AUM shows the less continentality, i.e, strong control by the oceanic ITCZ.

Characterizing Diurnal and Seasonal Cycles in Monsoon Systems from TRMM and CEOP Observations

NASA Technical Reports Server (NTRS)

Lau, William K. M.

2007-01-01

The CEOP Inter-Monsoon Study (CIMS) is one of the two main science drivers of CEOP that aims to (a) provide better understanding of fundamental physical processes in monsoon regions around the world, and (b) demonstrate the synergy and utility of CEOP data in providing a pathway for model physics evaluation and improvement. As the data collection phase for EOP-3 and EOP-4 is being completed, two full annual cycles (2003-2004) of research-quality data sets from satellites, reference sites, and model output location time series (MOLTS) have been processed and made available for data analyses and model validation studies. This article presents preliminary results of a CIMS study aimed at the characterization and intercomparison of all major monsoon systems. The CEOP reference site data proved its value in such exercises by being a powerful tool to cross-validate the TRMM data, and to intercompare with multi-model results in ongoing work. We use 6 years (1998-2003) of pentad CEOP/TRMM data with 2 deg x 2.5 deg. latitude-longitude grid, over the domain of interests to define the monsoon climatological diurnal and annual cycles for the East Asian Monsoon (EAM), the South Asian Monsoon (SAM), the West Africa Monsoon (WAM), the North America/Mexican Monsoon (NAM), the South American Summer Monsoon (SASM) and the Australian Monsoon (AUM). As noted, the TRMM data used in the study were cross-validated using CEOP reference site data, where applicable. Results show that the observed diurnal cycle of rain peaked around late afternoon over monsoon land, and early morning over the oceans. The diurnal cycles in models tend to peak 2-3 hours earlier than observed. The seasonal cycles of the EAM and SAM show the strongest continentality, i.e, strong control by continental processes away from the ITCZ. The WAM, and the AUM shows the less continentality, i.e, strong control by the oceanic ITCZ.

Brine shrimp development in space: ground-based data to shuttle flight results

NASA Technical Reports Server (NTRS)

Spooner, B. S.; DeBell, L.; Hawkins, L.; Metcalf, J.; Guikema, J. A.; Rosowski, J.

1992-01-01

The brine shrimp, Artemia salina, has been used as a model system to assess microgravity effects on developing organisms. Following fertilization and early development, the egg can arrest in early gastrula as a dehydrated cyst stage that is stable to harsh environments over long time periods. When salt water is added, the cysts can reactivate, with embryonic development and egg hatching occurring in about 24 h. A series of larval molts or instars, over about a 2 week period, results in the adult crustacean. We have assessed these developmental events in a closed syringe system, a bioprocessing module, in ground-based studies, and have conducted preliminary in-orbit experiments aboard the Space Shuttle Atlantis during the flights of STS-37 and STS-43. Although the in-flight data are limited, spectacular degrees of development have been achieved.

Ultraviolet radiation induces dose-dependent pigment dispersion in crustacean chromatophores.

PubMed

Gouveia, Glauce Ribeiro; Lopes, Thaís Martins; Neves, Carla Amorim; Nery, Luiz Eduardo Maia; Trindade, Gilma Santos

2004-10-01

Pigment dispersion in chromatophores as a response to UV radiation was investigated in two species of crustaceans, the crab Chasmagnathus granulata and the shrimp Palaemonetes argentinus. Eyestalkless crabs and shrimps maintained on either a black or a white background were irradiated with different UV bands. In eyestalkless crabs the significant minimal effective dose inducing pigment dispersion was 0.42 J/cm(2) for UVA and 2.15 J/cm(2) for UVB. Maximal response was achieved with 10.0 J/cm(2) UVA and 8.6 J/cm(2) UVB. UVA was more effective than UVB in inducing pigment dispersion. Soon after UV exposure, melanophores once again reached the initial stage of pigment aggregation after 45 min. Aggregated erythrophores of shrimps adapted to a white background showed significant pigment dispersion with 2.5 J/cm(2) UVA and 0.29 J/cm(2) UVC. Dispersed erythrophores of shrimps adapted to a black background did not show any significant response to UVA, UVB or UVC radiation. UVB did not induce any significant pigment dispersion in shrimps adapted to either a white or a black background. As opposed to the tanning response, which only protects against future UV exposure, the pigment dispersion response could be an important agent protecting against the harmful effects of UV radiation exposure.

Study of oil-water partitioning of a chemical dispersant using an acute bioassay with marine crustaceans

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

Wells, P.G.; Abernethy, S.; Mackay, D.

1982-01-01

The toxicity of seawater dispersions of a chemical dispersant to two marine crustaceans was investigated in the presence and absence of various quantities of a non-toxic mineral oil. From the results and a physical-chemical partitioning analysis, a limiting value of the oil-water partition coefficient of the toxic compounds is deduced suggesting that essentially all of the toxic compounds in the dispersant will partition into solution in water following dispersant application to an oil spill. This conclusion simplifies interpretation and prediction of the toxic effects of a dispersed oil spill. The combined bioassay-partitioning procedure may have applications to the study ofmore » the toxicity of other complex mixtures such as industrial effluents.« less

Roles of crustacean hyperglycaemic hormone in ionic and metabolic homeostasis in the Christmas Island blue crab, Discoplax celeste.

PubMed

Turner, Lucy M; Webster, Simon G; Morris, Stephen

2013-04-01

There is a growing body of evidence implicating the involvement of crustacean hyperglycaemic hormone (CHH) in ionic homeostasis in decapod crustaceans. However, little is known regarding hormonally influenced osmoregulatory processes in terrestrial decapods. As many terrestrial decapods experience opposing seasonal demands upon ionoregulatory physiologies, we reasoned that these would make interesting models in which to study the effect of CHH upon these phenomena. In particular, those (tropical) species that also undergo seasonal migrations might be especially informative, as we know relatively little regarding the nature of CHHs in terrestrial decapods, and hormonally mediated responses to seasonal changes in metabolic demands might also be superimposed or otherwise integrated with those associated with ionic homeostasis. Using Discoplax celeste as a model crab that experiences seasonal extremes in water availability, and exhibits diurnal and migratory activity patterns, we identified two CHHs in the sinus gland. We biochemically characterised (cDNA cloning) one CHH and functionally characterised (in terms of dose-dependent hyperglycaemic responses and glucose-dependent negative feedback loops) both CHHs. Whole-animal in situ branchial chamber (22)NaCl perfusion experiments showed that injection of both CHHs increased gill Na(+) uptake in a seasonally dependent manner, and (51)Cr-EDTA clearance experiments demonstrated that CHH increased urine production by the antennal gland. Seasonal and salinity-dependent differences in haemolymph CHH titre further implicated CHH in osmoregulatory processes. Intriguingly, CHH appeared to have no effect on gill Na(+)/K(+)-ATPase or V-ATPase activity, suggesting unknown mechanisms of this hormone's action on Na(+) transport across gill epithelia.

The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions

PubMed Central

Raupach, Michael J.; Barco, Andrea; Steinke, Dirk; Beermann, Jan; Laakmann, Silke; Mohrbeck, Inga; Neumann, Hermann; Kihara, Terue C.; Pointner, Karin; Radulovici, Adriana; Segelken-Voigt, Alexandra; Wesse, Christina; Knebelsberger, Thomas

2015-01-01

During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequences. PMID:26417993

The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions.

PubMed

Raupach, Michael J; Barco, Andrea; Steinke, Dirk; Beermann, Jan; Laakmann, Silke; Mohrbeck, Inga; Neumann, Hermann; Kihara, Terue C; Pointner, Karin; Radulovici, Adriana; Segelken-Voigt, Alexandra; Wesse, Christina; Knebelsberger, Thomas

2015-01-01

During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequences.

Long-term effects of chronic light pollution on seasonal functions of European blackbirds (Turdus merula).

PubMed

Dominoni, Davide M; Quetting, Michael; Partecke, Jesko

2013-01-01

Light pollution is known to affect important biological functions of wild animals, including daily and annual cycles. However, knowledge about long-term effects of chronic exposure to artificial light at night is still very limited. Here we present data on reproductive physiology, molt and locomotor activity during two-year cycles of European blackbirds (Turdus merula) exposed to either dark nights or 0.3 lux at night. As expected, control birds kept under dark nights exhibited two regular testicular and testosterone cycles during the two-year experiment. Control urban birds developed testes faster than their control rural conspecifics. Conversely, while in the first year blackbirds exposed to light at night showed a normal but earlier gonadal cycle compared to control birds, during the second year the reproductive system did not develop at all: both testicular size and testosterone concentration were at baseline levels in all birds. In addition, molt sequence in light-treated birds was more irregular than in control birds in both years. Analysis of locomotor activity showed that birds were still synchronized to the underlying light-dark cycle. We suggest that the lack of reproductive activity and irregular molt progression were possibly the results of i) birds being stuck in a photorefractory state and/or ii) chronic stress. Our data show that chronic low intensities of light at night can dramatically affect the reproductive system. Future studies are needed in order to investigate if and how urban animals avoid such negative impact and to elucidate the physiological mechanisms behind these profound long-term effects of artificial light at night. Finally we call for collaboration between scientists and policy makers to limit the impact of light pollution on animals and ecosystems.

Effects of different limestone particle sizes in the diet of broiler breeders post molting on their performance, egg quality, incubation results, and pre-starter performance of their progeny.

PubMed

Bueno, I J M; Surek, D; Rocha, C; Schramm, V G; Muramatsu, K; Dahlke, F; Maiorka, A

2016-04-01

An experiment was conducted to test the hypothesis that a coarse limestone diet improves productivity, reproductive performance and the calcium utilization of molted broiler breeders. In total, 640 broiler breeder females, 73-week-old and sixty-four 27-week-old cockerels, Cobb 500, were evaluated during 10 weeks, according to a randomized block design composed of 4 treatments with 8 replicates each. Treatments consisted of diets with the inclusion of 100% fine limestone-fine PS (0.2 mm GMD-geometric mean diameter); PS1: 30% fine limestone+70% limestone with 1.0 mm GMD; PS2: 30% fine limestone+70% limestone with 2.0 mm GMD; and PS3: 30% fine limestone+70% limestone with 3.0 mm GMD. Calcium retention in the gizzard of the breeders, bone characteristics, and breeder performance, egg characteristics, eggshell quality, incubation performance, chick quality and yield, chick pre-starter live performance, and chick bone characteristics were determined. There was no significant difference (P>0.05) in the rate of lay, percentage of non-settable eggs, egg weight, egg shape index, egg specific gravity, eggshell weight, thickness, and percentage hatchability and egg weight loss of broiler breeders fed with diets with different limestone particle sizes. The chick quality and yield, chick pre-starter live performance, and chick bone characteristics were not affected (P>0.05) by any of the limestone particle sizes. It was concluded that live and reproductive performance parameters of broiler breeders post molting is not affected by limestone particle size in the feed. © 2016 Poultry Science Association Inc.

Embryonic integument and "molts" in Manduca sexta (Insecta, Lepidoptera).

PubMed

Ziese, Stefanie; Dorn, August

2003-02-01

embryo of M. sexta secretes three covers at approximately the same developmental stage. A marked difference: the second embryonic cover, which in Hemimetabola clearly exhibits a cuticular organization, has instead a membranous, cuticulin-like structure. We see the difference as the result of an evolutionary reductional process promoted by the redundancy of embryonic covers in the egg shell. Embryonic "molts" also occur in noninsect arthropods; their phylogenetical aspects are discussed. Copyright 2002 Wiley-Liss, Inc.

Functional analysis of the promoter of the molt-inhibiting hormone (mih) gene in mud crab Scylla paramamosain.

PubMed

Zhang, Xin; Huang, Danping; Jia, Xiwei; Zou, Zhihua; Wang, Yilei; Zhang, Ziping

2018-04-01

In this study, the 5'-flanking region of molt-inhibiting hormone (MIH) gene was cloned by Tail-PCR. It is 2024 bp starting from the translation initiation site, and 1818 bp starting from the predicted transcription start site. Forecast analysis results by the bioinformatics software showed that the transcription start site is located at 207 bp upstream of the start codon ATG, and TATA box is located at 240 bp upstream of the start codon ATG. Potential transcription factor binding sites include Sp1, NF-1, Oct-1, Sox-2, RAP1, and so on. There are two CpG islands, located at -25- +183 bp and -1451- -1316 bp respectively. The transfection results of luciferase reporter constructs showed that the core promoter region was located in the fragment -308 bp to -26 bp. NF-kappaB and RAP1 were essential for mih basal transcriptional activity. There are three kinds of polymorphism CA in the 5'-flanking sequence, and they can influence mih promoter activity. These findings provide a genetic foundation of the further research of mih transcription regulation. Copyright © 2017 Elsevier Inc. All rights reserved.

Role of crustacean hyperglycemic hormone (CHH) in the environmental stressor-exposed intertidal copepod Tigriopus japonicus.

PubMed

Kim, Bo-Mi; Jeong, Chang-Bum; Han, Jeonghoon; Kim, Il-Chan; Rhee, Jae-Sung; Lee, Jae-Seong

2013-09-01

To identify and characterize CHH (TJ-CHH) gene in the copepod Tigriopus japonicus, we analyzed the full-length cDNA sequence, genomic structure, and promoter region. The full-length TJ-CHH cDNA was 716 bp in length, encoding 136 amino acid residues. The deduced amino acid sequences of TJ-CHH showed a high similarity of the CHH mature domain to other crustaceans. Six conserved cysteine residues and five conserved structural motifs in the CHH mature peptide domain were also observed. The genomic structure of the TJ-CHH gene contained three exons and two introns in its open reading frame (ORF), and several transcriptional elements were detected in the promoter region of the TJ-CHH gene. To investigate transcriptional change of TJ-CHH under environmental stress, T. japonicus were exposed to heat treatment, UV-B radiation, heavy metals, and water-accommodated fractions (WAFs) of Iranian crude oil. Upon heat stress, TJ-CHH transcripts were elevated at 30 °C and 35 °C for 96 h in a time-course experiment. UV-B radiation led to a decreased pattern of the TJ-CHH transcript 48 h and more after radiation (12 kJ/m(2)). After exposure of a fixed dose (12 kJ/m(2)) in a time-course experiment, TJ-CHH transcript was down-regulated in time-dependent manner with a lowest value at 12h. However, the TJ-CHH transcript level was increased in response to five heavy metal exposures for 96 h. Also, the level of the TJ-CHH transcript was significantly up-regulated at 20% of WAFs after exposure to WAFs for 48 h and then remarkably reduced in a dose-dependent manner. These findings suggest that the enhanced TJ-CHH transcript level is associated with a cellular stress response of the TJ-CHH gene as shown in decapod crustaceans. This study is also helpful for a better understanding of the detrimental effects of environmental changes on the CHH-triggered copepod metabolism. Copyright © 2013 Elsevier Inc. All rights reserved.

Evidence for crustacean cardioactive peptide-like innervation of the gut in Locusta migratoria.

PubMed

Donini, Andrew; Ngo, Caroline; Lange, Angela B

2002-11-01

Hindguts from female Vth instar larvae, young adults (1-2 days) and old adults (>10 days) are equally sensitive to the crustacean cardioactive peptide (CCAP), with changes in contraction occurring at a threshold concentration of 10(-9)M and maximal responses observed at concentrations ranging between 10(-7) and 5x10(-6)M. An immunohistochemical examination of the gut of Locusta migratoria with an antiserum raised against CCAP revealed an extensive network of CCAP-like immunoreactive processes on the hindgut and posterior midgut via the 11th sternal nerve arising from the terminal abdominal ganglion. Anterograde filling of the 11th sternal nerve with neurobiotin revealed extensive processes and terminals on the hindgut. Retrograde filling of the branch of the 11th sternal nerve which innervates the hindgut with neurobiotin revealed two bilaterally paired cells in the terminal abdominal ganglion which co-localized with CCAP-like immunoreactivity. Results suggest that a CCAP-like substance acts as a neurotransmitter/neuromodulator at the locust hindgut.

High sequence variability among hemocyte-specific Kazal-type proteinase inhibitors in decapod crustaceans.

PubMed

Cerenius, Lage; Liu, Haipeng; Zhang, Yanjiao; Rimphanitchayakit, Vichien; Tassanakajon, Anchalee; Gunnar Andersson, M; Söderhäll, Kenneth; Söderhäll, Irene

2010-01-01

Crustacean hemocytes were found to produce a large number of transcripts coding for Kazal-type proteinase inhibitors (KPIs). A detailed study performed with the crayfish Pacifastacus leniusculus and the shrimp Penaeus monodon revealed the presence of at least 26 and 20 different Kazal domains from the hemocyte KPIs, respectively. Comparisons with KPIs from other taxa indicate that the sequences of these domains evolve rapidly. A few conserved positions, e.g. six invariant cysteines were present in all domain sequences whereas the position of P1 amino acid, a determinant for substrate specificity, varied highly. A study with a single crayfish animal suggested that even at the individual level considerable sequence variability among hemocyte KPIs produced exist. Expression analysis of four crayfish KPI transcripts in hematopoietic tissue cells and different hemocyte types suggest that some of these KPIs are likely to be involved in hematopoiesis or hemocyte release as they were produced in particular hemocyte types or maturation stages only.

Within-Site Variation in Feather Stable Hydrogen Isotope (δ2Hf) Values of Boreal Songbirds: Implications for Assignment to Molt Origin.

PubMed

Nordell, Cameron J; Haché, Samuel; Bayne, Erin M; Sólymos, Péter; Foster, Kenneth R; Godwin, Christine M; Krikun, Richard; Pyle, Peter; Hobson, Keith A

2016-01-01

Understanding bird migration and dispersal is important to inform full life-cycle conservation planning. Stable hydrogen isotope ratios from feathers (δ2Hf) can be linked to amount-weighted long-term, growing season precipitation δ2H (δ2Hp) surfaces to create δ2Hf isoscapes for assignment to molt origin. However, transfer functions linking δ2Hp with δ2Hf are influenced by physiological and environmental processes. A better understanding of the causes and consequences of variation in δ2Hf values among individuals and species will improve the predictive ability of geographic assignment tests. We tested for effects of species, land cover, forage substrate, nest substrate, diet composition, body mass, sex, and phylogenetic relatedness on δ2Hf from individuals at least two years old of 21 songbird species captured during the same breeding season at a site in northeastern Alberta, Canada. For four species, we also tested for a year × species interaction effect on δ2Hf. A model including species as single predictor received the most support (AIC weight = 0.74) in explaining variation in δ2Hf. A species-specific variance parameter was part of all best-ranked models, suggesting variation in δ2Hf was not consistent among species. The second best-ranked model included a forage substrate × diet interaction term (AIC weight = 0.16). There was a significant year × species interaction effect on δ2Hf suggesting that interspecific differences in δ2Hf can differ among years. Our results suggest that within- and among-year interspecific variation in δ2Hf is the most important source of variance typically not being explicitly quantified in geographic assignment tests using non-specific transfer functions to convert δ2Hp into δ2Hf. However, this source of variation is consistent with the range of variation from the transfer functions most commonly being propagated in assignment tests of geographic origins for passerines breeding in North America.

Physiological thermoregulation in a crustacean? Heart rate hysteresis in the freshwater crayfish Cherax destructor.

PubMed

Goudkamp, Jacqueline E; Seebacher, Frank; Ahern, Mark; Franklin, Craig E

2004-07-01

Differential heart rates during heating and cooling (heart rate hysteresis) are an important thermoregulatory mechanism in ectothermic reptiles. We speculate that heart rate hysteresis has evolved alongside vascularisation, and to determine whether this phenomenon occurs in a lineage with vascularised circulatory systems that is phylogenetically distant from reptiles, we measured the response of heart rate to convective heat transfer in the Australian freshwater crayfish, Cherax destructor. Heart rate during convective heating (from 20 to 30 degrees C) was significantly faster than during cooling for any given body temperature. Heart rate declined rapidly immediately following the removal of the heat source, despite only negligible losses in body temperature. This heart rate 'hysteresis' is similar to the pattern reported in many reptiles and, by varying peripheral blood flow, it is presumed to confer thermoregulatory benefits particularly given the thermal sensitivity of many physiological rate functions in crustaceans.

Deep-sea crustacean trawling fisheries in Portugal: quantification of effort and assessment of landings per unit effort using a Vessel Monitoring System (VMS)

NASA Astrophysics Data System (ADS)

Bueno-Pardo, Juan; Ramalho, Sofia P.; García-Alegre, Ana; Morgado, Mariana; Vieira, Rui P.; Cunha, Marina R.; Queiroga, Henrique

2017-01-01

Mapping and quantifying bottom trawling fishing pressure on the seafloor is pivotal to understand its effects on deep-sea benthic habitats. Using data from the Vessel Monitoring System of crustacean trawlers along the Portuguese margin, we have identified the most exploited areas and characterized the most targeted habitats and water depths. We estimated a total trawling effort of 69596, 66766, and 63427 h y-1 for the years 2012, 2013, and 2014 respectively which, considering the total landings estimated for this gear, yield values of 20.76, 21.06, and 19.11 kg of landed fish per trawled hour. The main trawling pressure is exerted in the South and Southwest Portuguese margins, on muddy and muddy-sand bottoms between 200 and 700 m water depths, while in the North and Central-West coasts a minor effort, at shallower waters and across a wider range of habitats, is also applied. The most landed species are crustaceans such as rose shrimp and Norway lobster, although this varies importantly between the different regions of Portugal, being fish and cephalopods the main captures in the Northern ports. We discuss the consequences of trawling for the impacted communities as well as the characteristics of the commercialization of these captures in Portugal.

Deep-sea crustacean trawling fisheries in Portugal: quantification of effort and assessment of landings per unit effort using a Vessel Monitoring System (VMS)

PubMed Central

Bueno-Pardo, Juan; Ramalho, Sofia P.; García-Alegre, Ana; Morgado, Mariana; Vieira, Rui P.; Cunha, Marina R.; Queiroga, Henrique

2017-01-01

Mapping and quantifying bottom trawling fishing pressure on the seafloor is pivotal to understand its effects on deep-sea benthic habitats. Using data from the Vessel Monitoring System of crustacean trawlers along the Portuguese margin, we have identified the most exploited areas and characterized the most targeted habitats and water depths. We estimated a total trawling effort of 69596, 66766, and 63427 h y−1 for the years 2012, 2013, and 2014 respectively which, considering the total landings estimated for this gear, yield values of 20.76, 21.06, and 19.11 kg of landed fish per trawled hour. The main trawling pressure is exerted in the South and Southwest Portuguese margins, on muddy and muddy-sand bottoms between 200 and 700 m water depths, while in the North and Central-West coasts a minor effort, at shallower waters and across a wider range of habitats, is also applied. The most landed species are crustaceans such as rose shrimp and Norway lobster, although this varies importantly between the different regions of Portugal, being fish and cephalopods the main captures in the Northern ports. We discuss the consequences of trawling for the impacted communities as well as the characteristics of the commercialization of these captures in Portugal. PMID:28098211

Effects of acidifying ocean conditions on growth and survival of two life stages of the blue crab, Callinectes sapidus.

NASA Astrophysics Data System (ADS)

Giltz, S.; Taylor, C.

2016-02-01

Blue crabs, Callinectes sapidus, begin their larval phase offshore and circulate for approximately 30 days before settling near shore. As crabs transition to the juvenile stage, they move into coastal or estuarine environments characterized by lower salinity. Presently the average pH of the ocean is 8.1, 30% down from the beginning of the industrial revolution and is forecasted to drop to 7.8 by 2100. Decreasing pH causes dissolution of calcium carbonate shells, but the overall effects on crustaceans, such as blue crabs, are unknown. This study investigated the effect of a lower pH environment on the growth, survival, carapace hardness and molt frequency of larval and juvenile blue crabs in the Northern Gulf of Mexico. Larval crabs showed delayed growth under low pH (7.8) conditions compared to crabs in a control (present day) pH (8.1) environment. Population crashes (complete mortality) were experienced in 55% of the low pH aquaria but not in any of the control aquaria, suggesting that acidification poses a mortality risk. Under low pH conditions the intermolt duration decreased in juveniles, but the body length and weight did not differ from crabs raised in the control pH. Larvae (in tanks that did not crash) and juveniles did not experience increased mortality from a lower pH, but there do appear to be sublethal effects on growth and molting that differ between life history stages.

Life histories and abundance of crustacean zooplankton in the outlet of Lake Superior, 1971-72

USGS Publications Warehouse

Selgeby, James H.

1975-01-01

In sampling throughout a year, at about 3-wk intervals, of the crustacean zooplankton discharged from Lake Superior through the St. Marys River, 30 species were collected, including three not previously recorded for the lake: the copepod Cyclops strenuus, and the cladocerans Alona costata and Alonella acutirostris. Five copepods, Cyclops bicuspidatus thomasi, Diaptomus ashlandi, D. sicilis, Limnocalanus macrurus, and Senecella calanoides were present in the plankton throughout the year while three other copepods, Diaptomus minutus, Epischura lacustris, and Mesocyclops edax, along with all cladocerans, were present only during summer and fall. Five species of copepods, Diaptomus sicilis, D. minutus, Limnocalanus macrurus, Senecella calanoides, and Epischura lacustris produced a single generation annually; three other copepods and all cladocerans produced two or more generations. All species breed 1-3 mo later in Lake Superior than in lakes Michigan and Erie.

Effects of a new molt-inducing insecticide, tebufenozide, on zooplankton communities in lake enclosures.

PubMed

Kreutzweiser, D P; Thomas, D R

1995-10-01

: A potent ecdysone agonist, tebufenozide, has recently been developed as a molt-inducing insecticide to control defoliating lepidopterans. As part of continuing research efforts to assess the effectiveness and environmental safety of this material for insect pest management in Canadian forests, tebufenozide (RH-5992-2F) was applied to large lake enclosures and the effects on zooplankton communities were evaluated. There were significant treatment effects at all test concentrations (0.07-0.66 mg L(-1) tebufenozide). Concentration-dependent reductions in the abundance of cladocerans indicated that there were direct toxic effects of tebufenozide on this group of macrozooplankton. There were no indications of direct toxic effects on copepods. Significant increases in abundance of rotifers in treated enclosures at the three higher test concentrations were coincident with reductions in cladocerans and indicated secondary effects of the insecticide on the abundance of microzooplankton. There were no significant differences among treated and control enclosures in chlorophyll a concentrations, indicating that tebufenozide did not have direct effects on phytoplankton biomass, nor did the alterations in the zooplankton communities of treated enclosures have measurable secondary effects on phytoplankton biomass. Daytime dissolved oxygen concentrations were significantly higher in treated enclosures than in controls, indicating that the perturbation to biotic communities of some treated enclosures was sufficient to induce measurable changes in system-level functional attributes. Recovery of zooplankton communities in the enclosures occurred within 1-2 months at 0.07 and 0.13 mg l(-1) and by the following summer (12-13 months) at 0.33 and 0.66 mg l(-1).

Ultraviolet filters in stomatopod crustaceans: diversity, ecology and evolution.