Sample records for decapods

  1. CRUSTACEAN ISSUES ] 3 Decapod Crustacean Phylogenetics

    E-print Network

    Wetzer, Regina

    . Crandall, and Darryl L. Felder Ł\\ CRC Press J Taylor & Francis Group #12;Decapod Crustacean Phylogenetics, U. S. A. CRC Press is an imprint of the Taylor & Francis Croup, an informa business #12;CRC Press by Taylor & Francis Group, I.I.G CRC Press is an imprint of'Taylor & Francis Group, an In forma business

  2. Alien Decapod Crustaceans in the Southwestern Atlantic Ocean

    Microsoft Academic Search

    Marcos Tavares

    \\u000a Thirteen marine alien species of decapod crustaceans have been recorded from the Southwestern Atlantic. Five species of alien\\u000a decapods have established local populations: Charybdis hellerii (Brazil), Eurypanopeus depressus (Uruguay and Argentina), Palaemon macrodactylus (Argentina), Pyromaia tuberculata (Brazil and Argentina) and Rhithropanopeus harrisii (Brazil). The history and distribution of these species is reviewed. Also discussed is the local penaeid shrimp culture,

  3. Predictive modelling and spatial mapping of freshwater fish and decapod assemblages using GIS and neural networks

    Microsoft Academic Search

    Michael K. Joy; Russell G. Death

    2004-01-01

    SUMMARY 1. We used stream fish and decapod spatial occurrence data extracted from a national database and recent surveys with geospatial landuse data, geomorphologic, climatic, and spatial data in a geographical information system (GIS) to model fish and decapod occurrence in the Wellington Region, New Zealand. 2. To predict the occurrence of each species at a site from a common

  4. Warm-water decapods and the trophic amplification of climate in the North Sea.

    PubMed

    Lindley, J A; Beaugrand, G; Luczak, C; Dewarumez, J-M; Kirby, R R

    2010-12-23

    A long-term time series of plankton and benthic records in the North Sea indicates an increase in decapods and a decline in their prey species that include bivalves and flatfish recruits. Here, we show that in the southern North Sea the proportion of decapods to bivalves doubled following a temperature-driven, abrupt ecosystem shift during the 1980s. Analysis of decapod larvae in the plankton reveals a greater presence and spatial extent of warm-water species where the increase in decapods is greatest. These changes paralleled the arrival of new species such as the warm-water swimming crab Polybius henslowii now found in the southern North Sea. We suggest that climate-induced changes among North Sea decapods have played an important role in the trophic amplification of a climate signal and in the development of the new North Sea dynamic regime. PMID:20554562

  5. Warm-water decapods and the trophic amplification of climate in the North Sea

    PubMed Central

    Lindley, J. A.; Beaugrand, G.; Luczak, C.; Dewarumez, J.-M.; Kirby, R. R.

    2010-01-01

    A long-term time series of plankton and benthic records in the North Sea indicates an increase in decapods and a decline in their prey species that include bivalves and flatfish recruits. Here, we show that in the southern North Sea the proportion of decapods to bivalves doubled following a temperature-driven, abrupt ecosystem shift during the 1980s. Analysis of decapod larvae in the plankton reveals a greater presence and spatial extent of warm-water species where the increase in decapods is greatest. These changes paralleled the arrival of new species such as the warm-water swimming crab Polybius henslowii now found in the southern North Sea. We suggest that climate-induced changes among North Sea decapods have played an important role in the trophic amplification of a climate signal and in the development of the new North Sea dynamic regime. PMID:20554562

  6. 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.

  7. 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 diel rhythm of behaviour. Species evolved in a photically variable environment where intra- and inter-specific interactions change along with the community structure over 24 h. Accordingly, the regulation of their biology through a biological clock may be the major evolutionary constraint that is responsible for their reported bathymetric distributions. In this review, our aim is to propose a series of innovative guidelines for a discussion of the modulation of behavioural rhythms of adult decapod crustaceans, focusing on the deep waters of the continental margin areas of the Mediterranean as a paradigm for other marine zones of the world. PMID:20959158

  8. [In life determination of the physiological status of decapod crustaceans (Crustacea: Decapoda) by hematological characteristics].

    PubMed

    Aleksandrova, E N; Kovacheva, N P

    2010-01-01

    The application of hematological analysis techniques to detecting the physiological status of the economically valued decapods during their culturing, and in monitoring of the condition of their natural populations, is restrained by the incomplete knowledge of these invertebrates circulatory system and its properties. Scarce data on the use of hematological indicators for determining the physiological status of decapods may be found sporadically in published sources; there is shortage of basic standards needed for interpretation of the analytical results. In this regard the paper considers some data on the major properties of hemolymph and its cellular elements; on methods of their examination; and on the results of application of hematological characteristics to assessing the physiological condition of various species of decapods. The hematological indicators suitable for the analysis of live decapods include: time of coagulation and buffer characteristic of hemolymph; concentration of total proteins, copper, calcium, glucose and lactates in it; total number of hemocytes with the consideration of granulocytes share. PMID:20469604

  9. Structural components of eelgrass ( Zostera marina ) meadows in the lower Chesapeake Bay—Decapod crustacea

    Microsoft Academic Search

    K. L. Heck; R. J. Orth

    1980-01-01

    Otter trawl collections of eelgrass habitats in the lower Chesapeake Bay during 1976–1977 produced 14 species of decapod crustaceans.\\u000a These collections were dominated by palaemonid shrimp (Palaemonetes spp.), blue crabs (Callinectes sapidus), and sand shrimp (Crangon septemspinosa), each of which exhibited unimodal seasonal abundance curves with large summer peaks. Decapod abundance was positively correlated\\u000a with plant biomass throughout the year.

  10. Haemolymph protein composition and copper levels in decapod crustaceans

    NASA Astrophysics Data System (ADS)

    Depledge, M. H.; Bjerregaard, P.

    1989-06-01

    Variations in haemolymph protein composition and concentration, in copper content and copper distribution in the tissue of decapod crustaceans are reviewed. Haemocyanin is the major haemolymph constituent (> 60%); the remaining proteins (in order of concentration) include coagulogen, apohaemocyanin, hormones and antisomes. Moulting, nutritional state, infection, hypoxia and salinity fluctuations are the major factors affecting the relative proportions and total quantities of the haemolymph proteins. With regard to haemocyanin, the changes in concentration during the moult cycle are principally associated with changes in haemolymph volume, rather than with changes in total haemocyanin content due to synthesis or catabolism. The role of the midgut gland in regulating haemolymph copper and haemocyanin concentration has been re-evaluated. More than 50% of the whole body copper load is stored in the haemolymph. In contrast, less than 3% of the copper load resides in the midgut gland. The latter has little potential for regulating haemolymph copper levels, at least in the short term (hours to a few days), though it may be involved in regulating haemocyanin levels over longer periods (weeks to months). The total copper content of the haemolymph remains within a narrow range, except during starvation when levels may decrease. Consequently, variations in the copper content of soft tissues, which constitute only 20% of decapod dry weight, do not significanlty alter whole body copper concentrations. Evidence that copper released following haemocyanin catabolism becomes bound to metallothionein for later use in the resynthesis of haemocyanin is reviewed and found to be inconclusive. The amount of copper that can be stored in this way is trivial compared with the amount of copper required to permit significant changes in haemolymph haemocyanin concentration. Average tissue copper requirements, calculated during the present study, are approx. 4 times higher than previous theoretical estimates.

  11. 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

  12. Primary structures of decapod crustacean metallothioneins with special emphasis on freshwater and semi-terrestrial species.

    PubMed

    Pedersen, S N; Pedersen, K L; Hřjrup, P; Depledge, M H; Knudsen, J

    1996-11-01

    Cadmium injections induced only a single form of metallothionein (MT) in the midgut gland of Potamon potamios, whereas the same treatment induced two isoforms in Astacus astacus. The only difference between the two latter isoforms was that one had an extra N-terminal methionine residue. MT from P. potamios showed structural differences from other decapod crustacean MTs. It contained a Gly-Thr motif at positions 8 and 8a, which had previously been found only in certain vertebrate and molluscan MTs. Furthermore P. potamios MT contained two to three times as many glutamic acid residues as normally found in decapod crustacean MT. The primary structure of MT from the freshwater crayfish A. astacus showed a high degree of sequence identity with MT from other decapod crustaceans, especially the marine astacidean Homarus americanus, although two valine residues were unexpectedly found at positions 8 and 21, where lysine residues are normally found. PMID:8921011

  13. Adult neurogenesis in the decapod crustacean brain: A hematopoietic connection?

    PubMed Central

    Beltz, Barbara S.; Zhang, Yi; Benton, Jeanne L.; Sandeman, David C.

    2011-01-01

    New neurons are produced and integrated into circuits in the adult brains of many organisms, including crustaceans. In some crustacean species, the 1st- generation neuronal precursors reside in a niche exhibiting characteristics analogous to mammalian neurogenic niches. However, unlike mammalian niches where several generations of neuronal precursors coexist, the lineage of precursor cells in crayfish is spatially separated allowing the influence of environmental and endogenous regulators on specific generations in the neuronal precursor lineage to be defined. Experiments also demonstrate that the 1st-generation neuronal precursors in the crayfish Procambarus clarkii are not self-renewing. A source external to the neurogenic niche must therefore provide cells that replenish the 1st-generation precursor pool, because although these cells divide and produce a continuous efflux of 2nd-generation cells from the niche, the population of 1st-generation niche precursors is not diminished with growth and aging. In vitro studies show that cells extracted from the hemolymph, but not other tissues, are attracted to and incorporated into the neurogenic niche, a phenomenon that appears to involve serotonergic mechanisms. We propose that in crayfish, the hematopoietic system may be a source of cells that replenish the niche cell pool. These and other studies reviewed here establish decapod crustaceans as model systems in which the processes underlying adult neurogenesis, such as stem cell origins and transformation, can be readily explored. Studies in diverse species where adult neurogenesis occurs will result in a broader understanding of fundamental mechanisms and how evolutionary processes may have shaped the vertebrate/mammalian condition. PMID:21929622

  14. Biofilms as food for decapods (Atyidae, Palaemonidae) in the River Murray, South Australia

    Microsoft Academic Search

    Adrienne Burns; Keith F. Walker

    2000-01-01

    Stable water levels and turbidity associated with flow regulation in the River Murray have promoted the growth of filamentous green algae and Cyanobacteria in biofilms on submerged wood. We investigated the assimilation of biofilm algae by two dominant consumers, the decapod crustaceans Macrobrachium australiense (Palaemonidae) and Paratya australiensis (Atyidae), in two river reaches differing in the extent of floodplain development,

  15. Distributional patterns of decapod crustaceans in the circum-Mediterranean area during the Oligo-Miocene

    NASA Astrophysics Data System (ADS)

    Hyžný, Matúš

    2015-04-01

    During the Oligocene and Miocene, the circum-Mediterranean area was a complex network of (mostly) shallow marine basins. Significant biogeographic differentiation of this area has been documented (Harzhauser et al. 2007), mainly during the Miocene, when connections between Proto-Mediterranean, Paratethys and Proto-Indo-West Pacific were intermittently opening and closing. These seaways allowed migration of marine faunas. Distributional patterns has so far been discussed for several different animal groups, especially for molluscs (e.g. Studencka et al. 1998; Harzhauser et al. 2002, 2003, 2007). To test these patterns with decapod crustaceans, a database has been compiled including all previously published Oligocene and Miocene decapod occurrences and newly gathered data from examined material deposited in the institutional collections. Decapod associations have been significant components of marine habitats since the Mesozoic times with ever-increasing importance throughout the Cenozoic. Müller (1979) argued that brachyuran decapods are among the best zoogeographical indicators. Although decapods were used as such indicators before (e.g. Schweitzer 2001; Feldmann & Schweitzer 2006), no detailed analysis of the circum-Mediterranean taxa has been conducted so far. Based on proposed anti-estuarine circulation pattern, decapods originated in the Proto-Mediterranean, and migrated both into the North Sea and the Paratethys. Moreover, during the Early Miocene the Rhine Graben served as a connection between the North Sea and the Paratethys which enabled faunal exchange. The Middle Miocene Proto-Mediterranean and Paratethys decapod assemblages as taken together were relatively homogeneous, although distinct due to increasing rate of endemites in the Paratethys during the Miocene. The research has been supported by FWF: Lise Meitner Program M 1544-B25. References Feldmann R.M. & Schweitzer C.E. 2006: Paleobiogeography of Southern Hemisphere decapod Crustacea. J. Paleontol. 80, 83-103. Harzhauser M., Kroh A., Mandic O., Piller W.E., Göhlich U., Reuter M. & Berning B. 2007: Biogeographic responses to geodynamics: a key study all around the Oligo-Miocene Tethyan Seaway. Zool. Anz. 246, 241-256. Harzhauser M., Mandic O. & Zuschin M. 2003: Changes in Paratethyan marine molluscs at the Early/Middle Miocene transition: diversity, palaeogeography and palaeoclimate. Acta Geol. Pol. 53, 323-339. Harzhauser M., Piller W.E. & Steininger F.F. 2002: Circum-Mediterranean Oligo/Miocene Biogeographic Evolution - the Gastropods' Point of View. Palaeogeogr., Palaeoclimatol., Palaeoecol. 183, 103-133. Müller P. 1979: The Indo-West-Pacific character of the Badenian decapod crustaceans of the Paratethys. In: VII International Congress on Mediterranean Neogene. Athens, September 27-October 2. Ann. Géol. Pays Hellén., Tome hors série 2, 865-869. Schweitzer C.E. 2001: Paleobiogeography of Cretaceous and Tertiary decapod crustaceans of the North Pacific Ocean. J. Paleontol. 75, 808-826. Studencka B., Gontsharova I.A. & Popov S.V. 1998: The bivalve faunas as a basis for reconstruction of the Middle Miocene history of the Paratethys. Acta Geol. Pol. 48, 285-342.

  16. Fishes and decapod crustaceans of Cape Cod eelgrass meadows: Species composition, seasonal abundance patterns and comparison with unvegetated substrates

    Microsoft Academic Search

    K. L. Heck; K. W. Able; M. P. Fahay; C. T. Roman

    1989-01-01

    Bimonthly trawl samples from eelgrass and nearby unvegetated areas on Cape Cod, Massachusetts, showed greater species richness\\u000a in eelgrass meadows relative to unvegetated areas, and greater summer abundance in vegetation for decapod crustaceans and\\u000a fishes. The composition of eelgrass-associated decapods and fishes was dominated by cold-water taxa and was strikingly different\\u000a from that of the better studied eelgrass meadows of

  17. Spatial structure and seasonality of decapod crustacean populations on the northwestern Mediterranean slope

    Microsoft Academic Search

    Francesc Maynou; Ghard Y. Conan; Joan E. Cartes; Francisco Sardh

    1996-01-01

    Two trawl surveys designed for geostatistical analysis were made in spring and fall 199 1 on Nephrops norvegicus fishing grounds off Barcelona, Spain. High-resolution geostatistical techniques-a new tool for analyzing species assemblages-were used to map and assess species abundances. Of the 43 decapod crustacean species collected, the spatial structures of the nine most abundant were analyzed and mapped by kriging.

  18. Megabenthic decapod crustacean assemblages on the Galician continental shelf and upper slope (north-west Spain)

    Microsoft Academic Search

    A. C. Farińa; J. Freire; E. González-Gurriarán

    1997-01-01

    The structure of megabenthic decapod crustacean assemblages on the Galician (north-west Spain) continental shelf (100 to\\u000a 200 depth) and upper slope (200 to 500 m) was analyzed based on surveys carried out in autumn and spring, from 1980 to 1987.\\u000a Forty species belonging to 19 families were caught. The portunid crab Polybius henslowii, a species with pelagic phases, was the

  19. Utilization of submerged aquatic vegetation habitats by fishes and decapods in the Galvestion Bay Ecosystem, Texas

    E-print Network

    Scott, Elizabeth A.

    1998-01-01

    not result in substantial declines in fishery production. Zimmerman et al. (1990) compared faunal densities among marsh, SAV, and open-water habitats in Galveston Bay in two different salinity regimes. These researchers found that SAV (wigeongrass, Ruppia... Zimmerman et al. (1990) and Thomas et al. (1990), no other comparative analyses have been published concerning fish and decapod abundances in SAV versus other habitats within Galveston Bay. The uncertainty on SAV utilization and the minimal amount of data...

  20. Adult neurogenesis: Examples from the decapod crustaceans and comparisons with mammals

    PubMed Central

    Sandeman, David C.; Bazin, Francois; Beltz, Barbara S.

    2011-01-01

    Defining evolutionary origins is a means of understanding an organism’s position within the integrated web of living beings, and to not only to trace characteristics back in time, but also to project forward in an attempt to reveal relationships with more recently evolved forms. Both the vertebrates and arthropods possess condensed nervous systems, but this is dorsal in the vertbrates and ventral in the arthropods. Also, whereas the nervous system in the vertebrates develops from a neural tube in the embryo, that of the arthropods comes from an ectodermal plate. Despite these apparently fundamental differences, it is now generally accepted that life-long neurogenesis, the generation of functionally integrated neurons from progenitor cells, is a common feature of the adult brains of a variety of organisms, ranging from insects and crustaceans to birds and mammals. Among decapod crustaceans, there is evidence for adult neurogenesis in basal species of the Dendrobranchiata, as well as in more recent terrestrial, marine and fresh-water species. The widespread nature of this phenomenon in decapod species may relate to the importance of the adult-born neurons, although their functional contribution is not yet known. The many similarities between the systems generating neurons in the adult brains of decapod crustaceans and mammals, reviewed in this paper, suggest that adult neurogenesis is governed by common ancestral mechanisms that have been retained in a phylogenetically broad group of species. PMID:21396485

  1. Cloning and expression study of the lobster (Homarus americanus) vitellogenin: Conservation in gene structure among decapods.

    PubMed

    Tiu, Shirley Hiu Kwan; Hui, Ho-Lam; Tsukimura, Brian; Tobe, Stephen S; He, Jian-Guo; Chan, Siu-Ming

    2009-01-01

    This study reports the molecular characterization of the vitellogenin (Vg) of the lobster, Homarus americanus. Based on the annual collection of female lobsters, vitellogenesis commences in early March and continues through to September of each year. Using an antibody to vitellin of the lobster, H. americanus, several immunoreactive ovarian proteins were initially identified by Western blot analysis. The 80kDa protein contained the amino acid sequence APWGGNTPRC, identified subsequently by cDNA cloning to be identical to the lobster Vg. In common with the shrimp Metapenaeus ensis and crab Charybdis feriatus, the lobster HaVg1 gene comprises 14 introns and 15 exons. The deduced HaVg1 precursor is most similar to the Vg of the crayfish Cherax quadricarinatus (57%), followed by M. ensis (40-43% identity) and C. feriatus (38%). The results from genomic and RT-PCR cloning also confirmed the presence of multiple Vg genes in lobster. At early reproductive stages, the hepatopancreas HaVg1 transcript levels are low but increased to a maximum in animals with mature oocytes. The ovary, however, also expressed low levels of HaVg1. Using in vitro explant culture, treatment of hepatopancreas fragments with farnesoic acid or 20-hydroxyecdysone resulted in a significant stimulation in HaVg1 expression. From this study, it appears that Vg gene organization and expression pattern in decapods is highly conserved. Similar endocrine mechanisms may govern the process of vitellogenesis across the decapods. PMID:18992748

  2. ECDYSIS OF DECAPOD CRUSTACEANS IS ASSOCIATED WITH A DRAMATIC RELEASE OF CRUSTACEAN CARDIOACTIVE PEPTIDE INTO THE HAEMOLYMPH

    Microsoft Academic Search

    MARKUS K. PHLIPPEN; SIMON G. WEBSTER; J. SOOK CHUNG; HEINRICH DIRCKSEN

    On the basis of detailed analyses of morphological characteristics and behavioural events associated with ecdysis in a crab (Carcinus maenas) and a crayfish (Orconectes limosus), a comprehensive substaging system has been introduced for the ecdysis stage of the moult cycle of these decapod crustaceans. In a remarkably similar stereotyped ecdysis sequence in both species, a passive phase of water uptake

  3. Decapod burrows in mangrove?channel and back?reef environments at the Atlantic barrier reef, Belize

    Microsoft Academic Search

    Peter C. Dworschak; Jörg A. Ott

    1993-01-01

    Burrows of decapod crustaceans were investigated by in situ resin casting in various mangrove and back?reef environments. Alpheid shrimps (A. floridanus and A. heterochaelis) were the most numerous burrowing shrimps in soft muddy sediments of mangrove channels. Their burrows consist either of a single U or a series of U's inhabited by a pair of shrimp or are Y?shaped and

  4. Distribution of centrifugal neurons targeting the soma clusters of the olfactory midbrain among decapod crustaceans.

    PubMed

    Schmidt, M

    1997-03-28

    To determine the distribution of two systems of centrifugal neurons innervating the soma clusters of the olfactory midbrain across decapod crustaceans, brains of the following nine species comprising most infraorders were immunostained with antibodies against dopamine and the neuropeptides substance P and FMRFamide: Macrobrachium rosenbergii, Homarus americanus, Cherax destructor, Orconectes limosus, Procambarus clarkii, Astacus leptodactylus, Carcinus maenas, Eriocheir sinensis and Pagurus bernhardus. One system consisting of several neurons with dopamine-like immunoreactivity that originate in the eyestalk ganglia was present in the four crayfish but not in any other species. These neurons project mainly into the lateral soma clusters (cluster 10) comprising the somata of ascending olfactory projection neurons and innervate very sparsely the medial soma clusters (clusters 9 and 11) containing the somata of local interneurons. In the innervation pattern of the lateral cluster, the dopamine-immunoreactive neurons showed large species-specific differences. The other system comprises a pair of giant neurons with substance P-like immunoreactivity. These neurons have somata in the median protocerebrum of the central brain and major projections into the lateral clusters and the core of the olfactory lobes, the neuropils that are the first synaptic relay in the central olfactory pathway of decapods; minor arborizations are present in the medial clusters. The system of substance P-immunoreactive giant neurons was present and of great morphological similarity in all studied species. Only in one species, the shrimp Macrobrachium rosenbergii, evidence for co-localization of FMRFamide-like with substance P-like immunoreactivity in these neurons was obtained. These and previously collected data indicate that the centrifugal neurons with dopamine-like immunoreactivity may be associated with the presence of an accessory lobe, a second-order neuropil that receives input from the olfactory lobe and only occurs in spiny lobsters, clawed lobsters and crayfish. The pair of centrifugal giant neurons with substance P-like immunoreactivity, on the other hand, appears to be a constitutive component of the decapod crustacean brain that most likely is functionally associated with the olfactory lobe. Both systems apparently exert modulatory functions on olfactory information processing by preferentially targeting the somata of the projection neurons. Thus, in the olfactory projection neurons, the somata seem to be more directly involved in information processing than in most other neurons of the arthropod CNS. PMID:9106436

  5. Simultaneous hermaphroditism in the marine shrimp Lysmata wurdemanni (Caridea: Hippolytidae): an undescribed sexual system in the decapod Crustacea

    Microsoft Academic Search

    R. T. Bauer; G. J. Holt

    1998-01-01

    Simultaneous hermaphroditism with outcrossing, a previously unconfirmed sexual system in decapod crustaceans, is documented\\u000a in the shrimp Lysmata wurdemanni (Gibbes), using time-lapse video observations on mating in pairs of “female-phase” (FP) individuals. Copulations between\\u000a FPs resulted in successful spawning and development of embryos. However, female-phase hermaphrodites maintained in isolation\\u000a were unable to self-fertilize spawned eggs. All smaller individuals possessed characters

  6. Seasonal and Spatial Patterns of an Epibenthic Decapod Crustacean Assemblage in North-west Atlantic Continental Shelf Waters

    NASA Astrophysics Data System (ADS)

    Viscido, S. V.; Stearns, D. E.; Able, K. W.

    1997-09-01

    To examine seasonal and spatial patterns in a mobile marine assemblage, monthly samples were taken in triplicate with a 2-m beam trawl (6-mm mesh) at three separate stations (landward of the ridge, on the ridge top, and seaward of the ridge). The assemblage was of epibenthic decapod crustaceans, and was situated at a north-west Atlantic continental shelf, sandy ridge site. The assemblage was composed of nine species and was extremely variable over time and space. The sevenspine bay shrimp ( Crangon septemspinosa), the Atlantic rock crab ( Cancer irroratus), the spider crab ( Libinia emarginata) and the lady crab ( Ovalipes ocellatus) were the numerical dominants, comprising >98% of all decapods collected. Three of these species ( C. septemspinosa, C. irroratus, L. emarginata) exhibited marked spatial heterogeneity in abundance, with many fewer found on the ridge top than at either of the other two stations. Ovalipes ocellatuswas not as spatially variable. Crangonshowed two clear peaks, in spring and fall, as did Libinia, but neither appeared to use the site as a nursery area. Ovalipes ocellatusand C. irroratuseach showed a single peak of very small individuals in the summer and appeared to use this site for settlement. Komolgorov-Smirnov tests, analysis of variance and cluster analysis showed much less difference in assemblage structure between the landward and seaward stations than was demonstrated between either station and the ridge top. The presence of the sand ridge had a clear impact on the abundance and distribution of local decapod crustacean populations.

  7. Decapod crustacean larval communities in the Balearic Sea (western Mediterranean): Seasonal composition, horizontal and vertical distribution patterns

    NASA Astrophysics Data System (ADS)

    Torres, Asvin P.; Dos Santos, Antonina; Balbín, Rosa; Alemany, Francisco; Massutí, Enric; Reglero, Patricia

    2014-10-01

    Decapod crustaceans are the main target species of deep water bottom trawl fisheries in the Balearic Sea but little is known about their larval stages. This work focuses on the species composition of the decapod larval community, describing the main spatio-temporal assemblages and assessing their vertical distribution. Mesozooplankton sampling was carried out using depth-stratified sampling devices at two stations located over the shelf break and the mid slope, in the north-western and southern Mallorca in late autumn 2009 and summer 2010. Differences among decapod larvae communities, in terms of composition, adult's habitat such as pelagic or benthic, and distribution patterns were observed between seasons, areas and station. Results showed that for both seasons most species and developmental stages aggregated within the upper water column (above 75 m depth) and showed higher biodiversity in summer compared to late autumn. Most abundant species were pelagic prawns (e.g., Sergestidae) occurring in both seasons and areas. The larval assemblages' distributions were different between seasonal hydrographic scenarios and during situations of stratified and non-stratified water column. The vertical distribution patterns of different larval developmental stages in respect to the adult's habitat were analyzed in relation to environmental variables. Fluorescence had the highest explanatory power. Four clearly different vertical patterns were identified: two corresponding to late autumn, which were common for all the main larval groups and other two in summer, one corresponding to larvae of coastal benthic and the second to pelagic species larvae.

  8. On some interesting marine decapod crustaceans (Alpheidae, Laomediidae, Strahlaxiidae) from Lombok, Indonesia.

    PubMed

    Anker, Arthur; Pratama, Idham Sumarto; Firdaus, Muhammad; Rahayu, Dwi Listyo

    2015-01-01

    Several rare or uncommon, mostly infaunal decapod crustaceans are reported from intertidal and shallow subtidal habitats of Lombok, Indonesia. The alpheid shrimps Alpheus angustilineatus Nomura & Anker, 2005, Athanas shawnsmithi Anker, 2011, Jengalpheops rufus Anker & Dworschak, 2007, Salmoneus alpheophilus Anker & Marin, 2006, Salmoneus colinorum De Grave, 2004, and the laomediid mud-shrimp Naushonia carinata Dworschak, Marin & Anker, 2006, are reported for the first time since their original descriptions and represent new records for the marine fauna of Indonesia. The alpheid shrimps Alpheus macellarius Chace, 1988, Alpheus platyunguiculatus (Banner, 1953), Athanas japonicus Kubo, 1936, Athanas polymorphus Kemp, 1915, Leptalpheus denticulatus Anker & Marin, 2009, Richalpheus palmeri Anker & Jeng, 2006, Salmoneus gracilipes Miya, 1972, Salmoneus tricristatus Banner, 1959 and the laomediid mudshrimps Laomedia astacina De Haan, 1841 and Naushonia lactoalbida Berggren, 1992 are new records for Indonesian waters. The remaining alpheid shrimps, namely Alpheopsis yaldwyni Banner & Banner, 1973, Alpheus savuensis De Man, 1908, Automate anacanthopus De Man, 1910, Automate dolichognatha De Man, 1888, Salmoneus serratidigitus (Coutičre, 1896), and the strahlaxiid mud-shrimp Neaxius glyptocercus (von Martens, 1869), all previously known from Indonesia, are recorded for the first time from Lombok. Colour photographs are provided for all species reported, some shown in colour for the first time.  PMID:25661615

  9. Distribution and abundance of decapod crustacean larvae in the southeastern Bering Sea with emphasis on commercial species. Final report

    SciTech Connect

    Armstrong, D.A.; Incze, L.S.; Wencker, D.L.; Armstrong, J.L.

    1981-01-01

    Contents include: Distribution and abundance of king crab larvae, Paralithodes camtschatica and P. platypus in the southeast Bering Sea; Distribution and abundance of the larvae of tanner crabs in the southeastern Bering Sea; Distribution and abundance of other brachyuran larvae in the southeastern Bering Sea with emphasis on Erimacrus isenbeckii; Distribution and abundance of shrimp larvae in the southeastern Bering Sea with emphasis on pandalid species; Distribution and abundance of hermit crabs (Paguridae) in the southeasternBering Sea; Possible oil impacts on decapod larbae in the southeastern Bering Sea with emphesis on the St. George Basin.

  10. Seasonal bathymetric migrations of deep-sea fishes and decapod crustaceans in the NW Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Aguzzi, J.; Company, J. B.; Bahamon, N.; Flexas, M. M.; Tecchio, S.; Fernandez-Arcaya, U.; García, J. A.; Mechó, A.; Koenig, S.; Canals, M.

    2013-11-01

    Seasonal variations in the photophase length seem to drive migrations of marine animals, a phenomenon still largely unknown in deep-sea fishes and decapod crustaceans. Here, we report depth-oriented migrations of species living in the continental slope of the NW Mediterranean after repeated trawl sampling between 900 and 1500 m depths in four seasons. To understand the variations in the catchability of animals as a function of water depth, we analysed the relationship between population depth shifts and environmental factors by performing a multiparametric habitat monitoring at sea surface (PAR), in the water column (temperature and salinity), and on the seabed (organic matter flux and total mass flux). Significant connections are studied by NMDS and GAM analyses. Bathymetric changes in most targeted species are identified from winter, when distribution was the deepest, to spring and summer, and finally autumn, when the shallowest distribution was observed prior to a sudden bathymetric retreat. The analysis of size-class frequency distributions (Kolmogorov-Smirnov test) discards an effect of the juvenile recruitment on these bathymetric changes. Which environmental factor imparts seasonality to these depth-oriented migrations has not yet been clarified. A strong connection is found with water temperature and salinity, associated to flow of the Levantine Intermediate Water (LIW) and the Western Mediterranean Deep Water (WMDW). The studied depth range was affected by seasonal fluctuations of both water masses and the interphase amongst them. LIW showed a stronger seasonal pattern, getting warmer, saltier in autumn and fresher in winter. The migration of most species towards shallower depths in spring, summer and autumn, and the sudden migration to deeper grounds in winter could therefore be related to changes in LIW temperature and salinity.

  11. Bioaccumulation and retention kinetics of cadmium in the freshwater decapod Macrobrachium australiense.

    PubMed

    Cresswell, Tom; Simpson, Stuart L; Smith, Ross E W; Nugegoda, Dayanthi; Mazumder, Debashish; Twining, John

    2014-03-01

    The potential sources and mechanisms of cadmium bioaccumulation by the native freshwater decapods Macrobrachium species in the waters of the highly turbid Strickland River in Papua New Guinea were examined using (109)Cd-labelled water and food sources and the Australian species Macrobrachium australiense as a surrogate. Synthetic river water was spiked with environmentally relevant concentrations of cadmium and animals were exposed for 7 days with daily renewal of test solutions. Dietary assimilation of cadmium was assessed through pulse-chase experiments where prawns were fed separately (109)Cd-labelled fine sediment, filamentous algae and carrion (represented by cephalothorax tissue of water-exposed prawns). M. australiense readily accumulated cadmium from the dissolved phase and the uptake rate increased linearly with increasing exposure concentration. A cadmium uptake rate constant of 0.10 ± 0.05 L/g/d was determined in synthetic river water. During depuration following exposure to dissolved cadmium, efflux rates were low (0.9 ± 5%/d) and were not dependent on exposure concentration. Assimilation efficiencies of dietary sources were comparable for sediment and algae (48-51%), but lower for carrion (28 ± 5%) and efflux rates were low (0.2-2.6%/d) demonstrating that cadmium was well retained by M. australiense. A biokinetic model of cadmium accumulation by M. australiense predicted that for exposures to environmentally relevant cadmium concentrations in the Strickland River, uptake from ingestion of fine sediment and carrion would be the predominant sources of cadmium to the organism. The model predicted the total dietary route would represent 70-80% of bioaccumulated cadmium. PMID:24508761

  12. Community structure and dynamics of deep-water decapod assemblages from Le Danois Bank (Cantabrian Sea, NE Atlantic): Influence of environmental variables and food availability

    NASA Astrophysics Data System (ADS)

    Cartes, Joan E.; Serrano, Alberto; Velasco, Francisco; Parra, Santiago; Sánchez, Francisco

    2007-12-01

    The community structure of the decapod crustaceans inhabiting Le Danois Bank (Cantabrian Sea, NE Atlantic Ocean) was studied on two cruises performed in October 2003 and April 2004. Otter and beam-trawls were used to collect this fauna. At depths ranging between 455 and 1048 m, we found distinct decapod assemblages on the bank summit and deeper in the inner basin (between the bank and the continental shelf). The faunal discontinuity between these groups appeared at around 600 m (e.g. between 612 and 642 m in the basis of species replacement). The summit assemblage was characterized by low diversity (in terms of number and relative abundances of species) and by the dominance of hermit crabs ( Pagurus alatus, Anapagurus laevis, Pagurus excavatus), the crangonid Pontophilus spinosus and the squat lobster Munida sarsi. Species characterizing the deeper assemblage, which was richer in terms of diversity, were Munida tenuimana, Parapagurus pilosimanus, Pontophilus norvegicus, the crab Geryon trispinosus and a number of bathypelagic shrimps ( Sergia robusta, Acanthephyra pelagica and Pasiphaea tarda). Changes in decapod composition characterized by multidimensional scaling analyses were correlated with different variables, e.g. %mud and %organic matter (OM), temperature and salinity close to the bottom. Among those the %OM and %mud in sediments affected decapod distributions the most. The summit of the bank was covered by fine sediments with low proportion of mud (13.9-29.3%) and OM (2.55-3.50%). By contrast, sediment of the inner basin had a higher proportion of OM and mud (64.1-84.2%; 6.26-7.00%, respectively). The low proportion of mud at the summit of Le Danois Bank may explain the absence or scarcity of burrowing species (e.g. the lobster Nephrops norvegicus, the shrimps Calocaris macandreae and Alpheus glaber and the crab Goneplax rhomboides), that are dominant at similar depths (400-500 m) in the upper muddy assemblage on the mainland-continental slope in the Bay of Biscay (44-46°N). The dominance of certain species on the summit of submarine mounts can probably be related to their biology and feeding ecology. For example, pagurids are deposit feeders, even consuming marine snow (e.g. Chl- a identified in guts of Pagurus alatus), and they have low gut fullness (probably indicating a capacity to withstand long periods under starvation), that would favour their adaptability to a rather unpredictable habitat such as Le Danois Bank summit. Regarding prey availability, zooplankton/micronekton and infauna distributed around Le Danois Bank showed different depth-related patterns. Among zooplankton, mesopelagic decapods, mysids, and fishes were absent at the bank summit, while euphausiids exhibited high abundances over the summit. No significant trends with depth were found for infauna abundance, and for instance polychaete densities were similar both at the summit and the inner basin. Therefore, prey availability was lower for summit assemblages regarding zooplankton/micronekton. Patterns in mean size vs. depth were species specific for decapods, and the possible role of the bank summit as a recruitment area was not general for the whole decapod assemblage.

  13. A new look at embryonic development of the visual system in decapod crustaceans: neuropil formation, neurogenesis, and apoptotic cell death.

    PubMed

    Harzsch, S; Benton, J; Dawirs, R R; Beltz, B

    1999-05-01

    In recent years, comparing the structure and development of the central nervous system in crustaceans has provided new insights into the phylogenetic relationships of arthropods. Furthermore, the structural evolution of the compound eyes and optic ganglia of adult arthropods has been discussed, but it was not possible to compare the ontogeny of arthropod visual systems, owing to the lack of data on species other than insects. In the present report, we studied the development of the crustacean visual system by examining neurogenesis, neuropil formation, and apoptotic cell death in embryos of the American lobster, Homarus americanus, the spider crab, Hyas araneus, and the caridean shrimp, Palaemonetes argentinus, and compare these processes with those found in insects. Our results on the patterns of stem cell proliferation provide evidence that in decapod crustaceans and hemimetabolous insects, there exist considerable similarities in the mechanisms by which accretion of the compound eyes and growth of the optic lobes is achieved, suggesting an evolutionary conservation of these mechanisms. PMID:10235683

  14. Effects of insect and decapod exclusion and leaf litter species identity on breakdown rates in a tropical headwater stream.

    PubMed

    Rincón, José; Covich, Alan

    2014-04-01

    High species richness of tropical riparian trees influences the diversity of organic detritus entering streams, creating temporal variability in litter quantity and quality. We examined the influence of species of riparian plants and macroinvertebrate exclusion on leaf-litter breakdown in a headwater stream in the Luquillo Mountains of Puerto Rico. Leaf litter of Dacryodes excelsa (Burseraceae), Guarea guidonia (Meliaceae), Cecropia scheberiana (Moraceae), Manilkara bidentata (Sapotaceae), and Prestoea acuminata (Palmae) were incubated in litter bags in a pool of Quebrada Prieta. Fine mesh bags were used to exclude macroinvertebrates during leaf breakdown, and coarse mesh bags allowed access to decapod crustaceans (juvenile shrimps and crabs) and aquatic insects (mainly mayflies, chironomids, and caddisflies). D. excelsa and G. guidonia (in coarse- and fine-mesh bags) had significantly higher breakdown rates than C. scheberiana, M. bidentata, and P. acuminata. Breakdown rates were significantly faster in coarse-mesh bag treatments for all leaf types, thus indicating a positive contribution of macroinvertebrates in leaf litter breakdown in this headwater stream. After 42 days of incubation, densities of total invertebrates, mayflies and caddisflies, were higher in bags with D. excelsa and G. guidonia, and lower in P. acuminata, C. scheberiana y M. bidentata. Decay rates were positively correlated to insect densities. Our study highlights the importance of leaf identity and macroinvertebrate exclusion on the process of leaf litter breakdown in tropical headwater streams. PMID:25189075

  15. Recruitment patterns of decapod crustacean megalopae in a shallow inlet (SW Spain) related to life history strategies

    NASA Astrophysics Data System (ADS)

    González-Gordillo, J. I.; Arias, A. M.; Rodríguez, A.; Drake, P.

    2003-03-01

    Decapod crustacean megalopae were sampled weekly (spring/neap tides) during late-spring/summer of 1998 by using two planktonic nets located close to the surface and the bottom, at a fixed station in the mouth of the R?´o San Pedro inlet (SW Spain). Sampling was carried out during 25 h cycles to ascertain the flux of megalopae in relation to the main environmental (diel, tidal, tidal amplitude) cycles. The hypothesis that megalopae of some species may be using tidal-stream transport as a mechanism of re-invading the inlet was tested and the relationship between megalopal behaviour and life history strategy was analysed. In general, the flux of megalopae was higher during spring tides, but such differences were only statistically significant for Pisidia longicornis and Liocarcinus sp.2 due to the considerable interdate variation. With the exception of Macropodia sp., megalopae were more abundant close to the bottom. The diel/tidal flux of most abundant species suggested two different patterns of behaviour: megalopae of Liocarcinus spp., Panopeus africanus, Uca tangeri and Brachynotus sexdentatus seemed to be re-invading the inlet (specially at nocturnal floods), while megalopae of Ilia nucleus, Nepinnotheres pinnotheres and Macropodia sp. may have been just looking for a suitable place for settlement. The first group corresponded to the species whose zoeal development occurs in open sea, and the second one to species that complete their life cycle within the studied system, suggesting a relationship between the duration of the larval phase and the life cycle strategy of the species.

  16. Trophic transfer of trace metals from the polychaete worm Nereis diversicolor to the polychaete N. virens and the decapod crustacean Palaemonetes varians

    USGS Publications Warehouse

    Rainbow, P.S.; Poirier, L.; Smith, B.D.; Brix, K.V.; Luoma, S.N.

    2006-01-01

    Diet is an important exposure route for the uptake of trace metals by aquatic invertebrates, with trace metal trophic transfer depending on 2 stages - assimilation and subsequent accumulation by the predator. This study investigated the trophic transfer of trace metals from the sediment-dwelling polychaete worm Nereis diversicolor from metal-rich estuarine sediments in southwestern UK to 2 predators - another polychaete N. virens (Cu, Zn, Pb, Cd, Fe) and the decapod crustacean Palaemonetes varians (Cu, Zn, Pb, Cd, Fe, Ag, As, Mn). N. virens showed net accumulation of Cu, Zn, Pb and Cd from the prey; accumulation increased with increasing prey concentration, but a coefficient of trophic transfer decreased with increasing prey concentration, probably because a higher proportion of accumulated metal in the prey is bound in less trophically available (insoluble) detoxified forms. The trace metal accumulation patterns of P. varians apparently restricted significant net accumulation of metals from the diet of N. diversicolor to just Cd. There was significant mortality of the decapods fed on the diets of metal-rich worms. Metal-rich invertebrates that have accumulated metals from the rich historical store in the sediments of particular SW England estuaries can potentially pass these metals along food chains, with accumulation and total food chain transfer depending on the metal assimilation efficiencies and accumulation patterns of the animal at each trophic level. This trophic transfer may be significant enough to have ecotoxicological effects. ?? Inter-Research 2006.

  17. Parasites in the Fossil Record: A Cretaceous Fauna with Isopod-Infested Decapod Crustaceans, Infestation Patterns through Time, and a New Ichnotaxon

    PubMed Central

    Klompmaker, Adiël A.; Artal, Pedro; van Bakel, Barry W. M.; Fraaije, René H. B.; Jagt, John W. M.

    2014-01-01

    Parasites are common in modern ecosystems and are also known from the fossil record. One of the best preserved and easily recognisable examples of parasitism in the fossil record concerns isopod-induced swellings in the branchial chamber of marine decapod crustaceans. However, very limited quantitative data on the variability of infestation percentages at the species, genus, and family levels are available. Here we provide this type of data for a mid-Cretaceous (upper Lower Cretaceous, upper Albian) reef setting at Koskobilo, northern Spain, on the basis of 874 specimens of anomurans and brachyurans. Thirty-seven specimens (4.2%), arranged in ten species, are infested. Anomurans are more heavily infested than brachyurans, variability can be high within genera, and a relationship may exist between the number of specimens and infestation percentage per taxon, possibly suggesting host-specificity. We have also investigated quantitative patterns of infestation through geological time based on 88 infested species (25 anomurans, 55 brachyurans, seven lobsters, and one shrimp), to show that the highest number of infested species can be found in the Late Jurassic, also when corrected for the unequal duration of epochs. The same Late Jurassic peak is observed for the percentage of infested decapod species per epoch. This acme is caused entirely by infested anomurans and brachyurans. Biases (taphonomic and otherwise) and causes of variability with regard to the Koskobilo assemblage and infestation patterns through time are discussed. Finally, a new ichnogenus and -species, Kanthyloma crusta, are erected to accommodate such swellings or embedment structures (bioclaustrations). PMID:24667587

  18. High-mass-resolution direct-tissue MALDI-FTMS reveals broad conservation of three neuropeptides (APSGFLGMRamide, GYRKPPFNGSIFamide and pQDLDHVFLRFamide) across members of seven decapod crustaean infraorders

    Microsoft Academic Search

    Elizabeth A. Stemmler; Christopher R. Cashman; Daniel I. Messinger; Noah P. Gardner; Patsy S. Dickinson; Andrew E. Christie

    2007-01-01

    Matrix-assisted laser desorption\\/ionization Fourier transform mass spectrometry (MALDI-FTMS) has become an important method for identifying peptides in neural tissues. The ultra-high-mass resolution and mass accuracy of MALDI-FTMS, in combination with in-cell accumulation techniques, can be used to advantage for the analysis of complex mixtures of peptides directly from tissue fragments or extracts. Given the diversity within the decapods, as well

  19. Impact of hard-bottom substrata on the small-scale distribution of fish and decapods in shallow subtidal temperate waters

    NASA Astrophysics Data System (ADS)

    Wehkamp, Stephanie; Fischer, Philipp

    2013-03-01

    The micro-scale spatial distribution patterns of a demersal fish and decapod crustacean assemblage were assessed in a hard-bottom kelp environment in the southern North Sea. Using quadrats along line transects, we assessed the in situ fish and crustacean abundance in relation to substratum types (rock, cobbles and large pebbles) and the density of algae. Six fish and four crustacean species were abundant, with Ctenolabrus rupestris clearly dominating the fish community and Galathea squamifera dominating the crustacean community. Differences in the substratum types had an even stronger effect on the micro-scale distribution than the density of the dominating algae species. Kelp had a negative effect on the fish abundances, with significantly lower average densities in kelp beds compared with adjacent open areas. Averaged over all of the substrata, the most attractive substratum for the fish was large pebbles . In contrast, crustaceans did not show a specific substratum affinity. The results clearly indicate that, similar to other complex systems, significant micro-scale species-habitat associations occur in northern hard-bottom environments. However, because of the frequently harsh environmental conditions, these habitats are mainly sampled from ships with sampling gear, and the resulting data cannot be used to resolve small-scale species-habitat associations. A detailed substratum classification and community assessment, often only possible using SCUBA diving, is therefore important to reach a better understanding of the functional relationships between species and their environment in northern temperate waters, knowledge that is very important with respect to the increasing environmental pressure caused by global climate change.

  20. Neurogenesis in the central olfactory pathway of adult decapod crustaceans: development of the neurogenic niche in the brains of procambarid crayfish

    PubMed Central

    2012-01-01

    Background In the decapod crustacean brain, neurogenesis persists throughout the animal's life. After embryogenesis, the central olfactory pathway integrates newborn olfactory local and projection interneurons that replace old neurons or expand the existing population. In crayfish, these neurons are the descendants of precursor cells residing in a neurogenic niche. In this paper, the development of the niche was documented by monitoring proliferating cells with S-phase-specific markers combined with immunohistochemical, dye-injection and pulse-chase experiments. Results Between the end of embryogenesis and throughout the first post-embryonic stage (POI), a defined transverse band of mitotically active cells (which we will term 'the deutocerebral proliferative system' (DPS) appears. Just prior to hatching and in parallel with the formation of the DPS, the anlagen of the niche appears, closely associated with the vasculature. When the hatchling molts to the second post-embryonic stage (POII), the DPS differentiates into the lateral (LPZ) and medial (MPZ) proliferative zones. The LPZ and MPZ are characterized by a high number of mitotically active cells from the beginning of post-embryonic life; in contrast, the developing niche contains only very few dividing cells, a characteristic that persists in the adult organism. Conclusions Our data suggest that the LPZ and MPZ are largely responsible for the production of new neurons in the early post-embryonic stages, and that the neurogenic niche in the beginning plays a subordinate role. However, as the neuroblasts in the proliferation zones disappear during early post-embryonic life, the neuronal precursors in the niche gradually become the dominant and only mechanism for the generation of new neurons in the adult brain. PMID:22225949

  1. MitoPhAST, a new automated mitogenomic phylogeny tool in the post-genomic era with a case study of 89 decapod mitogenomes including eight new freshwater crayfish mitogenomes.

    PubMed

    Tan, Mun Hua; Gan, Han Ming; Schultz, Mark B; Austin, Christopher M

    2015-04-01

    The increased rate at which complete mitogenomes are being sequenced and their increasing use for phylogenetic studies have resulted in a bioinformatic bottleneck in preparing and utilising such data for phylogenetic analysis. Hence, we present MitoPhAST, an automated tool that (1) identifies annotated protein-coding gene features and generates a standardised, concatenated and partitioned amino acid alignment directly from complete/partial GenBank/EMBL-format mitogenome flat files, (2) generates a maximum likelihood phylogenetic tree using optimised protein models and (3) reports various mitochondrial genes and sequence information in a table format. To demonstrate the capacity of MitoPhAST in handling a large dataset, we used 81 publicly available decapod mitogenomes, together with eight new complete mitogenomes of Australian freshwater crayfishes, including the first for the genus Gramastacus, to undertake an updated test of the monophyly of the major groups of the order Decapoda and their phylogenetic relationships. The recovered phylogenetic trees using both Bayesian and ML methods support the results of studies using fragments of mtDNA and nuclear markers and other smaller-scale studies using whole mitogenomes. In comparison to the fragment-based phylogenies, nodal support values are generally higher despite reduced taxon sampling suggesting there is value in utilising more fully mitogenomic data. Additionally, the simple table output from MitoPhAST provides an efficient summary and statistical overview of the mitogenomes under study at the gene level, allowing the identification of missing or duplicated genes and gene rearrangements. The finding of new mtDNA gene rearrangements in several genera of Australian freshwater crayfishes indicates that this group has undergone an unusually high rate of evolutionary change for this organelle compared to other major families of decapod crustaceans. As a result, freshwater crayfishes are likely to be a useful model for studies designed to understand the evolution of mtDNA rearrangements. We anticipate that our bioinformatics pipeline will substantially help mitogenome-based studies increase the speed, accuracy and efficiency of phylogenetic studies utilising mitogenome information. MitoPhAST is available for download at https://github.com/mht85/MitoPhAST. PMID:25721538

  2. [Systems of chemoperception in decapod crayfish].

    PubMed

    Fedotov, V P

    2009-01-01

    The review presents data on some peripheral and central structures in the system of perception of chemical stimuli in crayfish and other Decapoda. The hair receptors on chelipeds, antennas, antennules are innervated by mechano-and chemoreceptor neurons. Antennules are the specialized crayfish chemoreceptor organs, on the surface of which groups of exteroceptors are located. There is an ordered disposition of exteroceptor receptive fields in the form of receptor hair bushes on claws of ambulatory feet (AF), antennas, antennules, and other movable appendages. Behavioral experiments have shown sensitivity of crayfish to odor of individuals of their gender, sex partners as well as the presence in crayfish of pheromones providing connection of female with offspring at the initial stages of the life cycle. Occasional chemosensory cells innervating hair bushes on the crayfish AF respond to amino acids, amines, nucleotides, and sugars. Minimal thresholds of reaction of the studied Decapoda chemoreceptors in response to some chemical compounds correspond to concentrations of 0.1-1 microM. For some chemoreceptors, dose-dependent effects have been shown. Alongside with monomodal chemoreceptors, the crayfish have bimodal receptor perceiving mechanical and chemical stimuli. The efficient response of crayfish chemoreceptors can be obtained to the substance that includes amino group with the hydrogen bridge with carboxyl group, contains no more than 3 carbon atoms in the chain, and is characterized by a certain stereoform. Among chemoreceptors there are fast and slow adapting cells. Efficiency of response of individual chemoreceptors depends on temperature of medium. Chemoreceptors reacting to ecdysterons have been revealed in crayfish. Ecdysterons play a great role in intra- and interspecies communications in Crustacea. Based on the study of efferent responses of interneurons of the first and higher orders in the first thoracic crayfish ganglion to stimulation of the own receptive fields, a concept is put forward of the structural-functional organization of afferent projections at the segmental level. Peculiarities of afferent projections from antennule chemoreceptors are considered. The data are presented on connections of these chemoreceptors with antennular, olfactory, and additional lobules, various cell groups, interneurons of the first, second, and third orders located in various brain parts. An attention is drawn to connections of serotonin neurons in glomeruli with endings of chemoreceptor neurons and projection of interneurons of the higher orders,. which are located in the internal medulla of the crayfish eye stalks. Several principles of integration of the chemoreceptor information in central parts of the crayfish nervous system are discussed. The giant serotonin neurons revealed in crayfish glomeruli most likely participate in formation of memory to certain chemical actions. Polymodal receptor signals in the central chain of the perception system activate autonomic centers, and the changes of the animal functional state can be evaluated from the heart responses. The crayfish heart responses recorded by novel noninvasive methods allow detection of the initial and other phases of the stress state at changes of the chemical quality of medium. Progress of the current biochemical and electrophysiological methods of study of chemoreceptors allow hoping for learning of fine chemoperception mechanisms in invertebrate and vertebrate animals. PMID:19370985

  3. Imaging mass spectrometry of neuropeptides in decapod crustacean neuronal tissues.

    PubMed

    DeKeyser, Stephanie S; Kutz-Naber, Kimberly K; Schmidt, Joshua J; Barrett-Wilt, Gregory A; Li, Lingjun

    2007-05-01

    Imaging mass spectrometry (IMS) of neuropeptides in crustacean neuronal tissues was performed on a MALDI-TOF/TOF instrument. Sample preparation protocols were developed for the sensitive detection of these highly complex endogenous signaling molecules. The neuromodulatory complements of the pericardial organ (PO) and brain of the Jonah crab, Cancer borealis, were mapped. Distributions of peptide isoforms belonging to 10 neuropeptide families were investigated using the IMS technique. Often, neuropeptides of high sequence homology were similarly located. However, two RFamide-family peptides and a truncated orcokinin peptide were mapped to locations distinct from other members of their respective families. Over 30 previously sequenced neuropeptides were identified based on mass measurement. For increased confidence of identification, select peptides were fragmented by post-source decay (PSD) and collisional-induced dissociation (CID). Collectively, this organ-level IMS study elucidates the spatial relationships between multiple neuropeptide isoforms of the same family as well as the relative distributions of neuropeptide families. PMID:17381149

  4. Organism response to habitat patchiness: species and habitat-dependent recruitment of decapod crustaceans

    Microsoft Academic Search

    David B Eggleston; Lisa L Etherington; Ward E Elis

    1998-01-01

    Habitat fragmentation from natural or anthropogenic causes is a common phenomenon in shallow water marine habitats such as seagrass beds and oyster reefs throughout the world. Thus, habitat- and scale-dependent information on how organisms perceive and respond to changes in the landscape is critical to efforts aimed at predicting the effects of habitat change on population abundance. In estuarine systems,

  5. Anatomy and physiology of digestive tract of Crustaceans Decapods reared in aquaculture

    Microsoft Academic Search

    H. J. CECCALDI

    The digestive tract of crustacea is complex. It is composed of a short oesophagum, a stomach with two bags, and internal wall with appendags specialized in grinding of feeds. These hard mastication pieces represent the gastric mill. Setae,. filters included in the stomach structure allow the separation between food particles and liquid compounds. Those one are coming over through filters

  6. Genomic sequence and experimental tractability of a new decapod shrimp model, Neocaridina denticulata.

    PubMed

    Kenny, Nathan J; Sin, Yung Wa; Shen, Xin; Zhe, Qu; Wang, Wei; Chan, Ting Fung; Tobe, Stephen S; Shimeld, Sebastian M; Chu, Ka Hou; Hui, Jerome H L

    2014-03-01

    The speciose Crustacea is the largest subphylum of arthropods on the planet after the Insecta. To date, however, the only publically available sequenced crustacean genome is that of the water flea, Daphnia pulex, a member of the Branchiopoda. While Daphnia is a well-established ecotoxicological model, previous study showed that one-third of genes contained in its genome are lineage-specific and could not be identified in any other metazoan genomes. To better understand the genomic evolution of crustaceans and arthropods, we have sequenced the genome of a novel shrimp model, Neocaridina denticulata, and tested its experimental malleability. A library of 170-bp nominal fragment size was constructed from DNA of a starved single adult and sequenced using the Illumina HiSeq2000 platform. Core eukaryotic genes, the mitochondrial genome, developmental patterning genes (such as Hox) and microRNA processing pathway genes are all present in this animal, suggesting it has not undergone massive genomic loss. Comparison with the published genome of Daphnia pulex has allowed us to reveal 3750 genes that are indeed specific to the lineage containing malacostracans and branchiopods, rather than Daphnia-specific (E-value: 10??). We also show the experimental tractability of N. denticulata, which, together with the genomic resources presented here, make it an ideal model for a wide range of further aquacultural, developmental, ecotoxicological, food safety, genetic, hormonal, physiological and reproductive research, allowing better understanding of the evolution of crustaceans and other arthropods. PMID:24619275

  7. A collection of Decapod Crustacea from Sumba, Lesser Sunda Islands, Indonesia

    Microsoft Academic Search

    L. B. Holthuis

    1978-01-01

    The Sumba-Expedition undertaken by Dr. E . Sutter of the Naturhistorisches Museum of Basle and Dr. A . Bühler of the Museum für Völkerkunde of the same town, visited the Lesser Sunda Islands, Indonesia, in 1949. Dr. Sutter, the zoologist, stayed in the islands from 19 May to 26 November; most of the time was spent by him in Sumba

  8. Identification of neuropeptides from the decapod crustacean sinus glands using nanoscale liquid chromatography tandem mass spectrometry.

    PubMed

    Fu, Qiang; Goy, Michael F; Li, Lingjun

    2005-11-25

    Neurosecretory systems are known to synthesize and secrete a diverse class of peptide hormones which regulate many physiological processes. The crustacean sinus gland (SG) is a well-defined neuroendocrine site that produces numerous hemolymph-borne agents including the most complex class of endocrine signaling molecules--neuropeptides. As an ongoing effort to define the peptidome of the crustacean SG, we determine the neuropeptide complements of the SG of the Jonah crab, Cancer borealis, and the Maine lobster, Homarus americanus, using nanoflow liquid chromatography electrospray ionization quadrupole time-of-flight (ESI-QTOF) MS/MS. Numerous neuropeptides were identified, including orcokinins, orcomyotropin, crustacean hyperglycemic hormone (CHH), CHH precursor-related peptides (CPRPs), red pigment concentrating hormone (RPCH), beta-pigment dispersing hormone (beta-PDH), proctolin and HL/IGSL/IYRamide. Among them, two novel orcokinins were de novo sequenced from the SG of H. americanus. Three CPRPs including a novel isoform were sequenced in H. americanus. Four new CPRPs were sequenced from the SG of C. borealis. Our results show that structural polymorphisms in CPRPs (and thus the CHH precursors) are common in Dendrobranchiata as well as in Pleocyemata. The evolutionary relationship between the CPRPs is also discussed. PMID:16214114

  9. DIURNAL ACTIVITY IN A GROUP OF GULF OF MAINE DECAPODS MARK NOVAK1)

    E-print Network

    Novak, Mark

    , Homarus americanus H. Milne Edwards, 1837, were, as expected, highest at night. The crabs Cancer borealis borealis Stimpson, 1859 und Carcinus maenas (L., 1758) fast ausschließlich tagaktiv waren. Cancer irroratus the American lobster, Homarus americanus H. Milne Edwards, 1837, the Jonah crab, Cancer borealis Stimpson, 1859

  10. High sequence variability among hemocyte-specific Kazal-type proteinase inhibitors in decapod crustaceans

    Microsoft Academic Search

    Lage Cerenius; Haipeng Liu; Yanjiao Zhang; Vichien Rimphanitchayakit; Anchalee Tassanakajon; M. Gunnar Andersson; Kenneth Söderhäll; Irene Söderhäll

    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

  11. Utilization of submerged aquatic vegetation habitats by fishes and decapods in the Galvestion Bay Ecosystem, Texas 

    E-print Network

    Scott, Elizabeth A.

    1998-01-01

    abundant species in vegetated habitats (Pigure 3) were Palaemonetes pugio, 40%; Callinectes sapidus, 15%, Penaeus setiferus, 12%; Penaeus aztecus, 9%, unidentified Penaeidae, 6%; sheepshead minnow, Cyprinodon variegatus, 5%; darter goby, Gobionellus.... Dominants in non-vegetated habitats (Figure 4) included Penaeus setiferus, 21%; Callinectes sapidus, 16%; gulf menhaden, Brevoortia patronus, 14%; Menidia beryllina, 11%; Palaemonetes pugio, 7%; Cyprinodon variegatus, 7%; unidentified Penaeidae, 6...

  12. 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. PMID:19715720

  13. Odors influencing foraging behavior of the California spiny lobster, Panulirus interruptus, and other decapod crustacea

    SciTech Connect

    Zimmer-Faust, R.K.; Case, J.F.

    1982-01-01

    Trapping experiments were conducted in the More Mesa coastal area of Santa Barbara, California, 4 km east of the U.C. Santa Barbara campus. Live intact and injured prey and excised tissues were placed in traps, in containers allowing odor release but preventing contacts with entering animals. Individuals of six prey species failed to attract lobsters when alive and intact, but some became attractive once injured. Excised tissues were the most effective baits. Abalone and mackerel muscle were attractive to lobsters but relatively nonattractive to crabs, while angel shark muscle was attractive to crabs but not to lobsters. Shrimp cephalothoraces were repellant to lobsters. Naturally occurring attractant and repellent tissues are thus identified and chemosensory abilities of lobsters and sympatric crabs are demonstrated to differ. Abalone muscle increased in attractivity following 1-2 days field exposure. Molecular weights of stimulants released by both weathered and fresh abalone were < 10,000 daltons with evidence suggesting that the 1000-10,000 dalton fraction may contribute significantly to attraction. Concentrations of total primary amines released from abalone muscle failed to differ from background levels, following an initial three (0-3h) period. Primary amines thus appear not to contribute directly to captures of lobsters, since animals were usually caught greater than or equal to 7 h after baits were positioned. Amino acids were the dominant contributors to present measurements of total primary amines, suggesting that these molecules may not direct lobster foraging behavior in the present experiments. 41 references, 4 figures, 8 tables.

  14. Genomic Sequence and Experimental Tractability of a New Decapod Shrimp Model, Neocaridina denticulata

    PubMed Central

    Kenny, Nathan J.; Sin, Yung Wa; Shen, Xin; Zhe, Qu; Wang, Wei; Chan, Ting Fung; Tobe, Stephen S.; Shimeld, Sebastian M.; Chu, Ka Hou; Hui, Jerome H. L.

    2014-01-01

    The speciose Crustacea is the largest subphylum of arthropods on the planet after the Insecta. To date, however, the only publically available sequenced crustacean genome is that of the water flea, Daphnia pulex, a member of the Branchiopoda. While Daphnia is a well-established ecotoxicological model, previous study showed that one-third of genes contained in its genome are lineage-specific and could not be identified in any other metazoan genomes. To better understand the genomic evolution of crustaceans and arthropods, we have sequenced the genome of a novel shrimp model, Neocaridina denticulata, and tested its experimental malleability. A library of 170-bp nominal fragment size was constructed from DNA of a starved single adult and sequenced using the Illumina HiSeq2000 platform. Core eukaryotic genes, the mitochondrial genome, developmental patterning genes (such as Hox) and microRNA processing pathway genes are all present in this animal, suggesting it has not undergone massive genomic loss. Comparison with the published genome of Daphnia pulex has allowed us to reveal 3750 genes that are indeed specific to the lineage containing malacostracans and branchiopods, rather than Daphnia-specific (E-value: 10?6). We also show the experimental tractability of N. denticulata, which, together with the genomic resources presented here, make it an ideal model for a wide range of further aquacultural, developmental, ecotoxicological, food safety, genetic, hormonal, physiological and reproductive research, allowing better understanding of the evolution of crustaceans and other arthropods. PMID:24619275

  15. RANGE EXTENSION OF BRACHYURAN CRABS ALONG THE BAJA CALIFORNIA COAST, MEXICO (CRUSTACEA: DECAPOD A) EXTENSION DEL AMBITO GEOGRAFICO DE CANGREJOS BRAQUIUROS A LO LARGO DE LA COSTA DE BAJA CALIFORNIA, MEXICO (CRUSTACEA: DECAPOD A)

    Microsoft Academic Search

    Ernesto Campos; Gerardo Ldpez; Facultad de Ciencias

    The study of brachyuran crabs collected from intertidal areas of the upper Gulf of California and the west coast of the Baja California peninsula, at Tortugas Bay, Baja California Sur, has produced a northern range extension for the following species: Hemus finneganae Garth, 1958; Microphrys platysoma (Stimpson, 1860); Eriphia squamata Stimpson, 1859; Xanthodius sternberghii Stimpson, 1859; Uca princeps princeps (Smith,

  16. The innervation of the pyloric region of the crab, Cancer borealis : Homologous muscles in decapod species are differently innervated

    Microsoft Academic Search

    Scott L. Hooper; Michael B. O'Neil; Robert Wagner; John Ewer; Jorge Golowasch; Eve Marder

    1986-01-01

    The muscles of the pyloric region of the stomach of the crab,Cancer borealis, are innervated by motorneurons found in the stomatogastric ganglion (STG). Electrophysiological recording and stimulating techniques were used to study the detailed pattern of innervation of the pyloric region muscles. Although there are two Pyloric Dilator (PD) motorneurons in lobsters, previous work reported four PD motorneurons in the

  17. Comparative strategies of heavy metal accumulation by crustaceans: zinc, copper and cadmium in a decapod, an amphipod and a barnacle

    Microsoft Academic Search

    P. S. Rainbow; S. L. White

    1989-01-01

    This study investigates the comparative strategies of accumulation under standardised laboratory conditions of the essential metals zinc and copper, and the non-essential metal cadmium by three crustaceans of different taxa; vizPalaemon elegans Rathke (Malacostraca: Eucarida: Decapoda),Echinogammarus pirloti (Sexton & Spooner) (Malacostraca: Peracarida: Amphipoda) and the barnacleElminius modestus Darwin (Cirripedia: Thoracica).

  18. The Polyhedra of the Occluded Baculoviruses of Marine Decapod Crustacea: A Unique Structure, Crystal Organization, and Proposed Model

    Microsoft Academic Search

    Hernan Aubert; Jocelyne Mari; Bonnie T. Poulos; Donald V. Lightner

    1997-01-01

    The baculoviruses of marine penaeid shrimp, PmSNPV and PvSNPV (MBV type and BP type, respectively), have distinctly different occlusion bodies (OBs) from those of the insect baculoviruses. In contrast to insect baculovirus, the penaeid baculovirus OB is unenveloped and formed by large subunits (SuOBs), as observed by electron microscopy after negative staining. The polyhedrin subunits measure 17 to 23 nm

  19. High Contents of Trimethylamine Oxide Correlating With Depth in Deep-Sea Teleost Fishes, Skates, and Decapod Crustaceans

    Microsoft Academic Search

    ROBERT H. KELLY; PAUL H. YANCEY

    1999-01-01

    In muscles of shallow-living marine animals, the osmolyte trimethylamine N-oxide (TMAO) is reportedly found (in millimoles of TMAO per kilogram of tissue wet weight) at 30-90 in shrimp, 5-50 in crabs, 61-181 in skates, and lo-70 in most teleost fish. Recently our labo- ratory reported higher levels (83-211 mmol\\/kg), correlating with habitat depth, in deep-sea gadiform teleosts. We now report

  20. Residues of oxytetracycline in cultured juvenile blue shrimp, Penaeus stylirostris (Crustacea: Decapod), fed medicated feed for 14 days

    Microsoft Academic Search

    Leone L Mohney; Rodney R Williams; Thomas A Bell; Donald V Lightner

    1997-01-01

    Juvenile shrimp fed for 14 days on oxytetracycline (OTC) medicated feed with a potency of 1500 mg OTC kg?1 of feed reached a level of 3.3 ?g OTC g?1 of shrimp tail muscle within 4 days, as measured by the microbial agar plate diffusion assay method for oxytetracycline in tissues, approved by the Association of Official Analytical Chemists. The concentration

  1. Comparative Population Structure of Two Deep-Sea Hydrothermal-Vent-Associated Decapods (Chorocaris sp. 2 and Munidopsis lauensis) from Southwestern Pacific Back-Arc Basins

    PubMed Central

    Thaler, Andrew David; Plouviez, Sophie; Saleu, William; Alei, Freddie; Jacobson, Alixandra; Boyle, Emily A.; Schultz, Thomas F.; Carlsson, Jens; Van Dover, Cindy Lee

    2014-01-01

    Studies of genetic connectivity and population structure in deep-sea chemosynthetic ecosystems often focus on endosymbiont-hosting species that are directly dependent on chemical energy extracted from vent effluent for survival. Relatively little attention has been paid to vent-associated species that are not exclusively dependent on chemosynthetic ecosystems. Here we assess connectivity and population structure of two vent-associated invertebrates—the shrimp Chorocaris sp. 2 and the squat lobster Munidopsis lauensis—that are common at deep-sea hydrothermal vents in the western Pacific. While Chorocaris sp. 2 has only been observed at hydrothermal vent sites, M. lauensis can be found throughout the deep sea but occurs in higher abundance around the periphery of active vents We sequenced mitochondrial COI genes and deployed nuclear microsatellite markers for both species at three sites in Manus Basin and either North Fiji Basin (Chorocaris sp. 2) or Lau Basin (Munidopsis lauensis). We assessed genetic differentiation across a range of spatial scales, from approximately 2.5 km to more than 3000 km. Population structure for Chorocaris sp. 2 was comparable to that of the vent-associated snail Ifremeria nautilei, with a single seemingly well-mixed population within Manus Basin that is genetically differentiated from conspecifics in North Fiji Basin. Population structure for Munidopsis lauensis was more complex, with two genetically differentiated populations in Manus Basin and a third well-differentiated population in Lau Basin. The unexpectedly high level of genetic differentiation between M. lauensis populations in Manus Basin deserves further study since it has implications for conservation and management of diversity in deep-sea hydrothermal vent ecosystems. PMID:24983244

  2. On some Panamerican Cretaceous crabs (Decapoda: Raninoida) 263 Decapod crustacean specimens recently collected from new and previously reported localities of USA, Mexico, and Colombia, as

    E-print Network

    Bermingham, Eldredge

    specimens recently collected from new and previously reported localities of USA, Mexico, and Colombia Colombia, Oklahoma and Mexico. Specimens of Cenomanocarcinus vanstraeleni from the Turonian of Mexico and Colombia include features not described previously for this species, such as variation in the shape

  3. MFR PAPER 1342 Some Protozoan Diseases of

    E-print Network

    MFR PAPER 1342 Some Protozoan Diseases of Decapod Crustaceans Thomas K. Sawyer and Sharon A. Mac protozoan parasites of decapod crustaceans into a brief summary of species which are deserving of con a bibliographic overview of the species of protozoans that are included here, but rather to summarize some of our

  4. Diseases of wild and cultured juvenile crustaceans: Insights from below the minimum landing size.

    PubMed

    Behringer, Donald C

    2012-06-01

    Decapod crustaceans (i.e., lobsters, crabs, and shrimps) are all subject to disease, both in the wild and in culture. No life stage appears to be immune to some form of pathogen or parasite. However, juveniles appear to be the targets of some of the most pervasive and consequential diseases. It is therefore surprising, given the enormous economic value of adult decapods, that we know so little about the effects of pathogens on their vulnerable life stage. Here I review the significant diseases reported for juvenile decapods that support fisheries and aquaculture, and highlight research that demonstrates the advantage of incorporating juveniles and ecology in studies of disease. PMID:22429832

  5. MARINE ECOLOGY -PROGRESS SERIES Mar. Ecol. Prog. Ser.

    E-print Network

    Gotelli, Nicholas J.

    . INTRODUCTION A rich fauna of decapod crustaceans inhabits the living branches of Pocillopora spp., a Pacific and Prince, 1983), Hawaii (Preston, 1973; Coles, 1980) and the Red Sea (associ- ates of Stylophora; Edwards

  6. Hidden Treasures in Stem Cells of Indeterminately Growing Bilaterian Invertebrates

    Microsoft Academic Search

    Günter Vogt

    Indeterminate growth, the life-long growth without fixed limits, is typical of some evolutionarily very successful aquatic\\u000a invertebrate groups such as the decapod crustaceans, bivalve molluscs and echinoderms. These animals enlarge their organs\\u000a also in the adult life period and can regenerate lost appendages and organs, which is in sharp contrast to mammals and most\\u000a insects. Interestingly, decapods, bivalves and echinoderms

  7. In-stream behaviour of threatened fishes and their food organisms based on remote video monitoring

    Microsoft Academic Search

    Brendan Ebner; Rhian Clear; Simon Godschalx; Matthew Beitzel

    2009-01-01

    Can remote underwater video be used to investigate the in-stream behaviour of small fishes and decapods? Diel activity of\\u000a two threatened freshwater fishes (Macquaria australasica and Gadopsis bispinosus), a palaemonid prawn and an atyid shrimp, was established from remote underwater video in a pool of an upland stream in the\\u000a current study. Decapods and large fishes (>5 cm TL) were nocturnal, whereas,

  8. Trophic relationships at intrannual spatial and temporal scales of macro and megafauna around a submarine canyon off the Catalonian coast (western Mediterranean)

    NASA Astrophysics Data System (ADS)

    Cartes, Joan E.; Fanelli, Emanuela; Papiol, Vanesa; Maynou, Francesc

    2010-04-01

    The spatial and temporal changes of near-bottom macrofauna (suprabenthos and macroplankton) and the trophic relationships of megabenthic decapod crustaceans were analyzed off the Catalonian coasts (western Mediterranean) around Berenguera submarine canyon in four periods (April and December 1991, March and July 1992) and four zones (within Berenguera Canyon at ca. 450 m, and on adjacent slope at ca. 400, 600 m and 1200 m). In March 1992, we found the highest macrofauna abundance and the smallest sizes in the canyon, suggesting a positive effect of river discharges on suprabenthos recruitment. By contrast, macroplankton (decapods, fishes and euphausiids) did not show higher recruitment into canyons. After analyzing the diet of 23 decapod crustaceans, we found a significant segregation between guilds feeding on zooplankton and on benthos. Zooplankton (euphausiids and Pasiphaeidae) and infauna (polychaetes, Calocaris macandreae and ophiuoroids) were consistently the main prey exploited by decapod crustaceans around Berenguera Canyon. We also found some macrophyte ( Posidonia oceanica) consumption, which was higher in periods of water column homogeneity (winter-spring and late autumn). Positive correlations between decapods' gut fullness ( F) and decapod abundance indicate feeding aggregations, while positive correlations were also found between F and Llobregat River (situated ca. 18 km from Berenguera head) flow 1 to 2 months before sampling. Increases in F were delayed only 1 month when zooplankton feeders were analyzed alone, while benthos feeders did not show significant relationships with any environmental variables. That indicates that the response of megabenthic decapods feeding on benthos to environmental shifts is slower than that of zooplankton feeders. The importance of river flows in enhancing food supply of macro- and megabenthos dwelling close to submarine canyons was apparent, with a delay in the fauna response of 0-2 months after river flow peaks.

  9. Effects of intrinsic and extrinsic factors on the diet of Bathyraja macloviana, a benthophagous skate.

    PubMed

    Barbini, S A; Scenna, L B; Figueroa, D E; Díaz de Astarloa, J M

    2013-07-01

    The effects of intrinsic (sex, maturity stage and body size) and extrinsic (depth and region) factors on the diet of Bathyraja macloviana, in the south-west Atlantic Ocean, were evaluated using a multiple-hypothesis modelling approach. Bathyraja macloviana fed mainly on polychaetes followed by amphipods, isopods and decapods. Effects of intrinsic and extrinsic factors on diet composition of this species were found. The consumption of polychaetes had a humped relationship with total length (L(T), and isopods and decapods increased with increasing L(T). Immature individuals preyed on amphipods more heavily than mature individuals. Furthermore, region and depth had an important effect on the consumption of isopods, decapods and amphipods. Such ontogenetic changes and spatial patterns may provide insights into understanding the regulatory mechanisms of marine communities. PMID:23808698

  10. Complete mitochondrial genome of the hydrothermal vent ghost shrimp Paraglypturus tonganus (Crustacea, Axiidea, Callianassidae).

    PubMed

    Kim, Se-Joo; Kim, Jonguk; Ahn, Dong-Ha; Ju, Se-Jong; Min, Gi-Sik; Kim, Sanghee

    2014-06-25

    Abstract Ghost shrimps are burrowing decapods that serve as bioturbators and habitat providers in seafloor environments. The hydrothermal vent ghost shrimp, Paraglypturus tonganus, was collected from a hydrothermal vent in the Tonga Arc. This species has a mitochondrial genome (mitogenome) of 15,924?bp in length with an AT content of 66.1%. The mitogenome was identical to the typical gene arrangement and transcriptional polarity of the infraorder Axiidea. Paraglypturus tonganus showed 65.3-70.1% nucleotide similarity with the known mitogenomes of other axiid shrimps. These results are useful for understanding the phylogenetic relationships among the members of Axiidea within the decapods. PMID:24963774

  11. Influence of trophic variables on the depth-range distributions and zonation rates of deep-sea megafauna: the case of the Western Mediterranean assemblages

    NASA Astrophysics Data System (ADS)

    Cartes, Joan E.; Carrassón, Maite

    2004-02-01

    We studied in a deep-sea megafaunal community the relationship of different trophic variables to the depth ranges inhabited by and depth zonation of species, after the ordination of fish and decapod crustaceans in feeding guilds. The variables studied included trophic level of species, food sources exploited, mean weight of predators and prey, feeding intensity and dietary diversity of species. We compiled data on the diets of 18 species of fish and 14 species of decapod crustaceans distributed between 862 and 2261 m in the Catalano-Balearic Basin (Western Mediterranean). Feeding guilds were identified for fish and decapods separately and at two depth strata (862-1400 and 1400-2261 m). The zonation rates (degree of depth overlap) between species within each trophic guild differed by guild and taxon (fish and decapods). The three guilds (G1, G2 and G3) of decapod crustaceans showed quite significantly distinct overlap. G1 (plankton feeders) showed the widest overlap (1326-1381 m) and G3 (benthos feeders) the narrowest (330-476 m). Among the four guilds established for fish, G1, comprising larger predators such as sharks, showed the lowest overlap (between 194 and 382 m). Macrourids overlap ranged between 122 and 553 m, the rest of benthopelagic feeders ranged between 423 and 970 m, and G3 (benthos feeders) gave overlaps between 867 and 1067 m. Significant differences were detected between the depth overlap of most feeding guilds excluding the paired comparisons between G1/macrourids, and G2/G3. Among decapods higher zonation rates (=lower depth overlap) were identified in those guilds occupying higher trophic levels (TL), with a similar, though not as general, trend among fish. In the ordination of species in feeding guilds, TL as indicated by ?15N measurements, was significantly correlated with Dimension 1 (D1) of ordination—MDS-analysis, both in fish and decapods at 862-1400 m. However, deeper (at 1400-2261 m), D1 was not significantly correlated with TL but with the mean weight of predator and prey in fish. In general, TL was again the main explanatory variable (accumulated variances, r2, explained by multi-linear regression—MLR-models between 0.54 and 0.69) both of the zonation rates and the depth ranges occupied by megafauna (fish and decapods together) throughout all the depth range studied. Possible relationships between zonation rates /depth distributions and other biological variables (i.e. egg size, fecundity) are also discussed.

  12. Direct evidence for the function of crustacean insulin-like androgenic gland factor (IAG): total chemical synthesis of IAG.

    PubMed

    Katayama, Hidekazu; Kubota, Nozomi; Hojo, Hironobu; Okada, Ayumi; Kotaka, Sayaka; Tsutsui, Naoaki; Ohira, Tsuyoshi

    2014-11-01

    Insulin-like androgenic gland factor (IAG) is presumed to be a sex differentiation factor so-called androgenic gland hormone (AGH) in decapod crustacean, although the function of IAG peptide has not yet been reported. In this study, we synthesized IAG from the prawn, Marsupenaeus japonicus, and its function was assessed by an in vitro bioassay. As a result, IAG with the insulin-type disulfide bond arrangement showed biological activity, whereas its disulfide isomer did not. These results strongly suggest that the native IAG peptide has an insulin-type disulfide, and it is the decapod AGH. PMID:25270404

  13. Functional properties of interganglionic motor neurons in the stomatogastric nervous system of the rock lobster

    Microsoft Academic Search

    J.-P. Vedel; M. Moulins

    1977-01-01

    1.In the decapod crustacea the stomatogastric nervous system, which involves the oesophageal (OG) and the stomatogastric (STGG) ganglia, commands the movements of the four successive parts of the foregut: oesophagus, cardiac sac, gastric mill and pylorus. The limited number of neurons (42) contained in the two ganglia are organized in several small networks producing various motor activities that are entirely

  14. Effects of pollution on freshwater invertebrates

    SciTech Connect

    Buikema

    1982-06-01

    The biological effects of acid rain, chlorination, heavy metals and other forms of pollution on freshwater invertebrates are examined in this review. Several methods for evaluating chronic toxicity to pesticide residues and synthetic fuels components are reviewed. The effects of pollutants is reviewed in detail for cladocera, amphipods, isopods, decapods, aquatic insects, molluscs, worms, and protozoa.(KRM)

  15. Localization and bacteriostasis of Vibrio introduced into the Pacific white shrimp, Litopenaeus vannamei

    E-print Network

    Burnett, Louis E.

    Localization and bacteriostasis of Vibrio introduced into the Pacific white shrimp, Litopenaeus a major role in bacterial uptake and bacteriostasis in penaeid shrimp. q 2005 Elsevier Ltd. All rights reserved. Keywords: Lymphoid organ; Vibrio; Real-time PCR; Penaeid shrimp; Decapod crustaceans

  16. Rosette-type tegumental glands associated with aesthetasc sensilla in the olfactory organ of the Caribbean spiny lobster, Panulirus argus

    Microsoft Academic Search

    Manfred Schmidt; Hsin Chien; Tizeta Tadesse; Malcolm E. Johns; Charles D. Derby

    2006-01-01

    The lateral antennular flagellum of decapod crustaceans bears unique olfactory sensilla, namely the aesthetascs, and other sensilla types. In this study, we identify a new major tissue in the lateral flagellum of the Caribbean spiny lobster, Panulirus argus, namely “aesthetasc tegumental glands” (ATGs), based on immunostaining with antibodies against CUB serine protease (Csp), in situ hybridization with csp-specific probes, labeling

  17. INFLUENCE OF FRESHWATER INPUT ON THE HABITAT VALUE OF OYSTER REEFS IN THREE SOUTHWEST FLORIDA ESTUARIES.

    EPA Science Inventory

    In order to examine the influence of freshwater input on the habitat value of oyster reefs, a spatiotemporal comparison of reef-resident fishes and decapod crustaceans was conducted during three seasonally dry and three seasonally wet months in three Southwest Florida estuaries: ...

  18. FOOD HABITS AND DIETARY OVERLAP OF SOME SHELF ROCKFISHES (GENUS SEBASTES) FROM

    E-print Network

    , had a more restricted diet comprised mostly ofeuphausiids. The numerical composition ofprey. Copepods. decapods. cephalo- pods. amphipods. fishes. and other pelagic prey were also consumed but were less important to the overall diet. Two species. S. {lavidus and S. diploproa. were relatively

  19. Influence of trophic variables on the depth-range distributions and zonation rates of deep-sea megafauna: the case of the Western Mediterranean assemblages

    Microsoft Academic Search

    Joan E. Cartes; Maite Carrassón

    2004-01-01

    We studied in a deep-sea megafaunal community the relationship of different trophic variables to the depth ranges inhabited by and depth zonation of species, after the ordination of fish and decapod crustaceans in feeding guilds. The variables studied included trophic level of species, food sources exploited, mean weight of predators and prey, feeding intensity and dietary diversity of species. We

  20. Substance P-like immunoreactivity in the stomatogastric nervous systems of the crab Cancer borealis and the lobsters Panulirus interruptus and Homarus americanus

    Microsoft Academic Search

    Diane Goldberg; Michael P. Nusbaum; Eve Marder

    1988-01-01

    The distribution of substance P-like immunoreactivity in the stomatogastric nervous systems of three decapod crustacean species, Cancer borealis, Homarus americanus, and Panulirus interruptus, was studied. The stomatogastric ganglion showed dense staining in the neuropil, but none in the somata. A single neuron stained in the esophageal ganglion. Lucifer yellow backfills and intracellular injections followed by incubation with the substance P

  1. Structural plasticity in the olfactory system of adult spiny lobsters: postembryonic development permits life-long growth, turnover, and regeneration

    Microsoft Academic Search

    Paul J. H. Harrison; Holly S. Cate; Pascal Steullet; Charles D. Derby

    Caribbean spiny lobsters ( Panulirus argus ) rely on their sense of olfaction for many behaviours. Growth of their olfactory systems, and maintenance of olfactory function, is ensured by structural change that occurs continuously throughout life. In this paper, we review recent studies on postembryonic development in the olfactory system of P. argus and several other decapod species. Major structural

  2. Ancient lakes as evolutionary reservoirs: evidence from the thalassoid gastropods of Lake Tanganyika

    Microsoft Academic Search

    Anthony B. Wilson; Matthias Glaubrecht; Axel Meyer

    2004-01-01

    Ancient lakes are often collectively viewed as evolutionary hot spots of diversification. East Africa's Lake Tanganyika has long been the subject of scientific interest owing to dramatic levels of endemism in species as diverse as cichlid fishes, paludomid gastropods, decapod and ostracod crustaceans and poriferans. It is the largest and deepest of the African rift lakes, and its endemic fauna

  3. SPECIATION IN ANCIENT LAKES Ecological correlates of species differences in the Lake

    E-print Network

    Loon, E. Emiel van

    SPECIATION IN ANCIENT LAKES Ecological correlates of species differences in the Lake Tanganyika Springer Science+Business Media B.V. 2008 Abstract The endemic crabs of Lake Tanganyika include for the maintenance of species diversity in Lake Tanganyika. Keywords Decapod Á Adaptive radiation Á Niche

  4. NURSERY ROLE OF SEAGRASS MEADOWS IN THE UPPER AND LOWER REACHES OF THE CHESAPEAKE BAY

    EPA Science Inventory

    A two year trawling and gill-netting study of vegetated and unvegetated bottoms near Parson's Island, Maryland and near the mouth of the York River, Virginia was carried out to assess the nursery function of submerged vegetation for population of fishes and decapod crustaceans in...

  5. GROWTH AND VARIATIONS IN LIPID CLASS AND FATTY ACID COMPOSITION DURING LARVAL DEVELOPMENT OF THE STONE CRAB, MENIPPE ADINA WILLIAMS AND FELDER, 1986.

    EPA Science Inventory

    Larval development in decapod crustaceans is marked by variable growth patterns and changes in weight and biochemical composition. Larvae of the stone crab, Menippe adina, were mass-reared under laboratory conditions (28?C; 20o/ooS) from hatching to the megalopa stage. Growth in...

  6. GROWTH AND VARIATIONS IN LIPID CLASS AND FATTY ACID COMPOSITION DURING LARVAL DEVELOPMENT OF THE STONE CRAB, MENIPPE ADINA WILLIAMS AND FELDER, 1986

    EPA Science Inventory

    Larval development in decapod crustaceans is marked by variable growth patterns and changes in weight and biochemical composition. Larvae of the stone crab, Menippe adina, were mass-reared under laboratory conditions (28|C; 20o/ooS) from hatching to the megalopal stage. Growth in...

  7. Crustacean haemocytes and haematopoiesis

    Microsoft Academic Search

    Mats W Johansson; Pia Keyser; Kallaya Sritunyalucksana; Kenneth Söderhäll

    2000-01-01

    Crustacean haemocytes play important roles in the host immune response including recognition, phagocytosis, melanization, cytotoxicity and cell–cell communication. Classification of the haemocyte types in decapod crustaceans is based mainly on the presence of cytoplasmic granules into hyaline cells, semigranular cells, and granular cells. Each cell type is active in defence reactions, for example; in crayfish, the hyaline cells are chiefly

  8. Brachyura (Decapoda, Crustacea) of phytobenthic communities of the sublittoral region of rocky shores of Rio de Janeiro and Săo Paulo, Brazil

    Microsoft Academic Search

    MARIA TERESA MENEZES DE SZÉCHY; VALÉRIA GOMES VELOSO; ÉDISON JOSÉ DE PAULA

    The density of Brachyura decapods was estimated in fourteen phytobenthic communities of the shallow sublittoral region of the coast of Rio de Janeiro and Săo Paulo States, Brazil. The variation in abundance of these crabs was analyzed relative to the degree of wave action, size and slope of the rock surfaces and dry weight of the macroalgae. Collec- tions were

  9. A molecular method for the detection of sally lightfoot crab larvae (Grapsus grapsus, Brachyura, Grapsidae) in plankton samples

    PubMed Central

    Ströher, Patrícia R.; Firkowski, Carina R.; Freire, Andrea S.; Pie, Marcio R.

    2011-01-01

    The decapod Grapsus grapsus is commonly found on oceanic islands of the Pacific and Atlantic coasts of the Americas. In this study, a simple, quick and reliable method for detecting its larvae in plankton samples is described, which makes it ideal for large-scale studies of larval dispersal patterns in the species. PMID:21931530

  10. Diet overlaps and feeding relationships between the year classes in the yellow perch (Perca flavescens)

    Microsoft Academic Search

    Allen Keast

    1977-01-01

    A comparative study of the diets of five year classes of perch in Lake Opinicon showed Year class 0 to be mainly Cladocera feeders, the Year class 11 to take a diversified range of insect larvae, whereas from Year class V onwards Anisoptera nymphs, decapods, and fish dominated the diet. Sizes of the dominant food items changed strikingly with growth,

  11. Role of environmental temperature in aging and longevity: insights from neurolipofuscin

    Microsoft Academic Search

    M. R. J Sheehy

    2002-01-01

    The available evidence for thermal modulation of neurolipofuscin deposition in poikilotherms is reviewed here and additional data are contributed. Mainly decapod crustacean models are employed and neurolipofuscin is treated as an index of physiological aging. In all cases, neurolipofuscin accumulation rate is positively correlated with environmental temperature but there appears to be lowered sensitivity in the thermal mid-range, an ‘optimum’

  12. Diel trophic interactions between vertically-migrating zooplankton and their fish predators in an eelgrass community

    Microsoft Academic Search

    A. I. Robertson; R. K. Howard

    1978-01-01

    Diel changes in the composition of crustacean zooplankton and the diets of fish predators from an intertidal eelgrass flat were monitored concurrently. The zooplankton is characterized by two major components. The obligate zooplankters (holoplanktonic calanoid copepods and meroplanktonic decapod larvae) appear to exhibit vertical migration, being present in higher densities near the surface of the water column at night. The

  13. Acute toxicity and synergism of cadmium and zinc in white shrimp, Penaeus setiferus, Juveniles

    SciTech Connect

    Vanegas, C.; Espina, S.; Botello, A.V.; Villanueva, S. [National Autonomous Univ. of Mexico, Mexico (Mexico)] [National Autonomous Univ. of Mexico, Mexico (Mexico)

    1997-01-01

    Toxic effects of individual heavy metals on decapod crustaceans have been reported frequently, but little information exists concerning interactions. Among the non-essential heavy metals, cadmium is one of the most hazardous elements in the aquatic environment; on the other hand, zinc is an essential element, but toxic when present in greater than trace amounts. Biological effects of cadmium in aquatic organisms are complex due to the interactions with both environmental variables and other toxic agents. In decapod crustaceans, the toxicity of cadmium and zinc is modified by salinity, temperature, hypoxia, calcium ion concentrations and life-cycle stage. Heavy metal pollution has increased in the coastal waters of the Gulf of Mexico, particularly in shrimp habitat. This study examined the toxicity of cadmium and zinc to white shrimp juveniles and looked at the interaction of the metals. 16 refs., 2 tabs.

  14. Semisubmersible oil platforms: understudied and potentially major vectors of biofouling-mediated invasions.

    PubMed

    Yeo, Darren C J; Ahyong, Shane T; Lodge, David M; Ng, Peter K L; Naruse, Tohru; Lane, David J W

    2010-01-01

    Biofouling has long been recognised as a major pathway for the introduction of non-indigenous species. This study records the decapods and stomatopod crustaceans fouling a semisubmersible oil platform dry docked for hull cleaning in Jurong Port, Singapore. Of the 25 species of decapods identified, 13 were non-indigenous and represent new records to Singapore waters. Of these, the crabs Glabropilumnus seminudus and Carupa tenuipes are known to be invasive in other parts of the world. The stomatopod, Gonodactylaceus randalli, is the first mantis shrimp recorded in a biofouling community. The richness and diversity of this fouling community, consisting of many vagile species, highlights the difference between platforms and ships. With the expansion of maritime oil and gas exploration, the threat posed by an expanded fleet of semisubmersible oil platforms translocating non-indigenous fouling communities across biogeographical boundaries is very serious. Scientists, policy-makers, and stakeholders should turn their attention to this growing problem. PMID:19927240

  15. Comparison of the roles of neurohormones in the regulation of blood distribution from the hearts of American and Japanese lobsters

    Microsoft Academic Search

    J. L. Wilkens; T. Kuramoto

    1998-01-01

    The decapod cardiovascular system consists of a single ventricle that pumps blood into seven arteries; previous work has\\u000a shown that the outflow distribution patterns of intact animals are variable. In the present study, flow recordings were made\\u000a from pairs of arteries in semi-isolated hearts whilst different cardioactive hormones were infused into the heart. Each hormone\\u000a (5-hydroxytryptamine, octopamine, dopamine, proctolin and

  16. Complete sequence of Litopenaeus vannamei (Crustacea: Decapoda) vitellogenin cDNA and its expression in endocrinologically induced sub-adult females

    Microsoft Academic Search

    Shaul Raviv; Shmuel Parnes; Carmen Segall; Claytus Davis; Amir Sagi

    2006-01-01

    The gene that encodes vitellogenin (Vg), the precursor of the major yolk protein, vitellin, is expressed during vitellogenesis in decapod crustaceans. In this study, we sequenced the full-length cDNA from the Pacific white shrimp Litopenaeus vannamei Vg gene (LvVg). This is the first open thelycum penaeid shrimp Vg cDNA to be sequenced. The transcript encodes a 2587 amino acid polypeptide

  17. Summer feeding strategy of the little auk ( Alle alle ) from Bjřrnřya, Barents Sea

    Microsoft Academic Search

    J. M. W?s?awski; L. Stempniewicz; F. Mehlum; S. Kwa?niewski

    1999-01-01

    Summer food of the little auks nesting on Bjornoya consisted of large copepods, decapod larvae and pelagic amphipods. Food\\u000a items of 4–6?mm constituted the most common prey size fraction. This prey size range appears to be optimal (most profitable)\\u000a with regard to the balance between mean individual mass and density of items in the surface layers of the sea. Little

  18. Glycoproteins from the Cuticle of the Atlantic Shore Crab Carcinus maenas: I. Electrophoresis and Western-Blot Analysis by Use of Lectins

    Microsoft Academic Search

    PHILIPPE COMPERE; MARIE-FRANCE JASPAR-VERSALI; GERHARD GOFFINET

    The protein and glycoprotein content of four different neutral or acidic solvent extracts (0.5 M KCl, 10% EDTA, 0.1 N HCl, or 2% acetic acid) from the mineralized exoskeleton of a decapod crustacean, the Atlantic shore crab Carcinus maenas, were characterized by quantitative anal- ysis of proteins, SDS-PAGE analysis, and probing with lectins on blots. The lectins used were Conconavalin

  19. Molecular characterization and expression of a crustin-like gene from Chinese mitten crab, Eriocheir sinensis

    Microsoft Academic Search

    Changkao Mu; Peilin Zheng; Jianmin Zhao; Lingling Wang; Huan Zhang; Limei Qiu; Yunchao Gai; Linsheng Song

    2010-01-01

    Crustin is a cysteine-rich antibacterial peptide which widely distributes within decapod crustaceans. In the present study, the cDNA encoding crustin-like peptide (designated CrusEs) was cloned from Chinese mitten crab Eriocheir sinensis by using rapid amplification of cDNA ends (RACE) approaches and expressed sequence tag analysis. The full-length cDNA of CrusEs was of 796bp, containing a 5? untranslated region (UTR) of

  20. Etisus evamuellerae, a new xanthid crab (Decapoda, Brachyura) from the Middle Miocene of Austria and Hungary

    PubMed Central

    Hyžný, M.; van Bakel, B.W.M.; Guinot, D.

    2015-01-01

    On the basis of several carapaces, a new species of xanthid crab, Etisus evamuellerae, is described from the Middle Miocene of the Vienna (Austria) and Great Hungarian basins. It differs from the coeval xanthids, Xantho moldavicus and Pilodius vulgaris, in having a distinctly protruding front and comparatively longer carapace. Contrary to those two species, the new one makes up for just a small percentage in the decapod crustacean assemblages studied. PMID:25983383

  1. Expression of recombinant eyestalk crustacean hyperglycemic hormone from the tropical land crab, Gecarcinus lateralis , that inhibits Y-organ ecdysteroidogenesis in vitro

    Microsoft Academic Search

    Tyler P. Zarubin; Ernest S. Chang; Donald L. Mykles

    2009-01-01

    Crustacean hyperglycemic hormone (CHH) is a pleiotropic neuropeptide that regulates carbohydrate and lipid metabolism, molting,\\u000a reproduction, and osmoregulation in decapod crustaceans. CHH elevates glucose levels in the hemolymph by stimulating glycogenolysis\\u000a in target tissues. It also inhibits ecdysteroidogenesis in the molting gland, or Y-organ (YO), possibly as a response to environmental\\u000a stress. CHH acts via binding to a membrane receptor

  2. Isolation of a cDNA encoding a CHH-family peptide from the silkworm Bombyx mori

    Microsoft Academic Search

    Hirotoshi Endo; Hiromichi Nagasawa; Toshiki Watanabe

    2000-01-01

    The crustacean hyperglycemic hormone (CHH) peptide family includes four types of neuropeptide in decapod and isopod crustaceans, and the ion-transport peptide in orthopteran insects. To identify a new member of this family in Insecta, a PCR-based search for cDNAs encoding CHH-family peptides was carried out in the silkworm Bombyx mori. A cDNA, named BmCHHL (Bombyx moriCHH-like protein), with an open

  3. Seasonal changes of benthic megafauna in the Ría de Muros e Noia (Galicia, North-West Spain)

    Microsoft Academic Search

    E. González-Gurriarán

    1986-01-01

    A community of decapod crustaceans (Brachyura) was sampled seasonally (October 1978–July 1979) from three habitats (raft, middle and beach) in the Ría de Muros e Noia (North-West Spain), with the purpose of studying spatial and temporal changes in the community and comparing with communities in the neighbouring Ría de Arousa, which supports an intense mussel (Mytilus edulis)-raft culture. The Portunidae

  4. Tissue distribution of 210 Po and 210 Pb in select marine species of the coast of Kudankulam, southern coast of Gulf of Mannar, India

    Microsoft Academic Search

    Mohan Feroz Khan; Samuel Godwin Wesley

    2011-01-01

    Activities of 210Po and 210Pb in various tissues of four species of decapod crabs and two species of cephalopod mollusks (cuttlefishes) of Kudankulam\\u000a coast were studied. A non-uniform distribution of these radionuclides was observed between the organs. Of all the tissues,\\u000a 210Po and 210Pb were found accumulated more in the hepatopancreas and intestine of crabs and in the digestive gland,

  5. Chemical Communication in Crayfish

    Microsoft Academic Search

    Thomas Breithaupt

    \\u000a Crayfish are a species rich group of large decapod crustaceans that inhabit freshwater environments. Having served as important\\u000a models for the study of the neural and hormonal control of behavior crayfish were among the first crustacean taxa that were\\u000a reported to use sex pheromones. Decades of research on crayfish chemical communication have, after initial controversies,\\u000a now generated a comprehensive picture

  6. Morphological and physiological development of anterior thoracic stretch receptors in two isopods, Armadillidium vulgare and Ligia exotica

    Microsoft Academic Search

    Masazumi Iwasaki; Ayako Ohata; Akiyoshi Niida

    2007-01-01

    Abdominal muscle receptor organs (MROs) monitor the position and movement of abdomen in crustaceans. Thoracic segments of\\u000a decapods are fused and immovable. It is speculated that MROs had retrograded simple shape, N-cells that lost receptor muscles,\\u000a a receptor cell and accessory nerves. We focused on the effect of segmental movement in respect to thoracic N-cells and MROs\\u000a in isopods that

  7. Book Review: The Private Life of Spiders by Paul Hillyard (2007)

    E-print Network

    Selden, Paul A.

    2010-01-01

    traditional textbook pattern with chapters devoted to morphology, taxo- nomic groups, silk production, mating, venom, and social spiders, but not forgetting spiders and man. The information contained is as much as in other spider books for the general public..., and larval char- acters), and with the importance of spermatozoal morphology, mating systems, vision, and parasite- host relationship in decapod evolution and phyloge- netics. The other four sections addressed specific groups of Decapoda. Section II...

  8. Mating behavior of Abdopus aculeatus (d’Orbigny 1834) (Cephalopoda: Octopodidae) in the wild

    Microsoft Academic Search

    Christine L. Huffard; Roy L. Caldwell; Farnis Boneka

    2008-01-01

    The mating system of Abdopus aculeatus incorporates sneaker matings, mate guarding, sex-specific body patterns, frequent copulations, and male–male competition\\u000a for mates, making it more similar to that of aggregating decapod cephalopods than any previously known octopus social system.\\u000a Large male–female A. aculeatus occupy ‘Adjacent’ (GA) dens and copulate frequently in mate-guarding situations over successive days. Nearby individuals copulate in ‘Temporary

  9. Distribution of phyllosoma lobster larvae (Crustacea: Decapoda: Reptantia: Scyllaridea) in the Gulf of Mexico in relation to currents and recruitment potential

    E-print Network

    Hammer, Richard Melvin

    1974-01-01

    marine food items in the world. Scyllaridea lobsters are not to be confused with the east coast american lobster, Homarus americanus, another decapod crustacean from the suborder Reptantia, section Macrura but of the superfamily Nephropsidea... and family Homaridae. A pelavic larva is present in the development of H. americanus but is of shorter duration than most phyllosoma larvae. A viable f 1she hy 0: . . ul" hfs - r', 'f ' ': ". "'ts 1f'. t, f: tropical-subtropical Atlantic Ocean anf...

  10. Feeding ecology of the deep-water blue-red shrimp Aristeus antennatus (Decapoda: Aristeidae) in the Greek Ionian Sea (E. Mediterranean)

    NASA Astrophysics Data System (ADS)

    Kapiris, Kostas; Thessalou-Legaki, Maria

    2011-01-01

    The feeding habits of the deep-sea blue-red shrimp Aristeus antennatus were determined based on the analysis of 1047 stomach contents, sampled in the Greek Ionian Sea (E. Mediterranean). The diet of this economically and biologically important decapod was studied in relation to the season, size class and sex. The diet of A. antennatus consisted of 54 different prey categories, and belonged mainly to smaller crustaceans (e.g. natantian decapods, euphausiids, tanaidaceans), molluscs, polychaetes, chaetognaths and, to a lesser extent, fishes. The above prey categories consisted of 71-82% of the relative abundance and total occurrence for males and 61-81% for females. Females seemed to be better fed than males (stomach fullness, food quality). A. antennatus displayed a highly diversified diet and the different feeding patterns were discussed. Diet composition showed slight seasonal fluctuations. The observed slight differences on A. antennatus diet among the western, central and eastern Mediterranean could be attributed to the more oligotrophic character of the eastern part of the basin. The principal factors driving the changes in the feeding strategy of this decapod among the seasons are the increased energy demands related to sexual requirements and the food availability in the marine environment. The ontogenetic changes in the shrimp's diet were relatively clear. Larger individuals exhibited selecting prey with a good swimming capacity (e.g. fishes), while the smaller individuals consumed prey with low mobility (e.g. copepods, ostracods).

  11. Allergenicity and allergens of amphipods found in nori (dried laver).

    PubMed

    Motoyama, Kanna; Hamada, Yuki; Nagashima, Yuji; Shiomi, Kazuo

    2007-09-01

    Gammaridean and caprellid amphipods, crustaceans of the order Amphipoda, inhabit laver culture platforms and, hence, are occasionally found in nori (dried laver) sheets. Amphipods mixed in nori may cause allergic reactions in sensitized patients, as is the case with other crustaceans, such as shrimp and crab, members of the order Decapoda. In this study, dried samples of amphipods (unidentified) found in nori and fresh samples of gammaridean amphipod (Gammarus sp., not accurately identified) and caprellid amphipod (Caprella equilibra) were examined for allergenicity and allergens using two species of decapods (black tiger prawn and spiny lobster) as references. When analyzed by ELISA, sera from crustacean-allergic patients reacted to extracts from amphipod samples, although less potently than to the extracts from decapods. In IgE-immunoblotting, a 37-kDa protein was found to be the major allergen in amphipods. Based on the molecular mass and the cross-reactivity with decapod tropomyosin evidenced by inhibition ELISA and inhibition immunoblotting, the 37-kDa protein was identified as amphipod tropomyosin. PMID:17691004

  12. Environmental and scale-dependent evolutionary trends in the body size of crustaceans.

    PubMed

    Klompmaker, Adiël A; Schweitzer, Carrie E; Feldmann, Rodney M; Kowalewski, Micha?

    2015-07-22

    The ecological and physiological significance of body size is well recognized. However, key macroevolutionary questions regarding the dependency of body size trends on the taxonomic scale of analysis and the role of environment in controlling long-term evolution of body size are largely unknown. Here, we evaluate these issues for decapod crustaceans, a group that diversified in the Mesozoic. A compilation of body size data for 792 brachyuran crab and lobster species reveals that their maximum, mean and median body size increased, but no increase in minimum size was observed. This increase is not expressed within lineages, but is rather a product of the appearance and/or diversification of new clades of larger, primarily burrowing to shelter-seeking decapods. This argues against directional selective pressures within lineages. Rather, the trend is a macroevolutionary consequence of species sorting: preferential origination of new decapod clades with intrinsically larger body sizes. Furthermore, body size evolution appears to have been habitat-controlled. In the Cretaceous, reef-associated crabs became markedly smaller than those in other habitats, a pattern that persists today. The long-term increase in body size of crabs and lobsters, coupled with their increased diversity and abundance, suggests that their ecological impact may have increased over evolutionary time. PMID:26156761

  13. Resolution of fine biological structure including small narcomedusae across a front in the Southern California Bight

    NASA Astrophysics Data System (ADS)

    McClatchie, Sam; Cowen, Robert; Nieto, Karen; Greer, Adam; Luo, Jessica Y.; Guigand, Cedric; Demer, David; Griffith, David; Rudnick, Daniel

    2012-04-01

    We sampled a front detected by SST gradient, ocean color imagery, and a Spray glider south of San Nicolas Island in the Southern California Bight between 14 and 18 October 2010. We sampled the front with an unusually extensive array of instrumentation, including the Continuous Underway Fish Egg Sampler (CUFES), the undulating In Situ Ichthyoplankton Imaging System (ISIIS) (fitted with temperature, salinity, oxygen, and fluorescence sensors), multifrequency acoustics, a surface pelagic trawl, a bongo net, and a neuston net. We found higher fluorescence and greater cladoceran, decapod, and euphausiid densities in the front, indicating increased primary and secondary production. Mesopelagic fish were most abundant in oceanic waters to the west of the front, market squid were abundant in the front associated with higher krill and decapod densities, and jack mackerel were most common in the front and on the shoreward side of the front. Egg densities peaked to either side of the front, consistent with both offshore (for oceanic squid and mesopelagic fish) and shelf origins (for white croaker and California halibut). We discovered unusually high concentrations of predatory narcomedusae in the surface layer of the frontal zone. Potential ichthyoplankton predators were more abundant either in the front (decapods, euphausiids, and squid) or shoreward of the front (medusae, chaetognaths, and jack mackerel). For pelagic fish like sardine, which can thrive in less productive waters, the safest place to spawn would be offshore because there are fewer potential predators.

  14. The complete mitochondrial genome sequence of the hydrothermal vent galatheid crab Shinkaia crosnieri (Crustacea: Decapoda: Anomura): A novel arrangement and incomplete tRNA suite

    PubMed Central

    Yang, Jin-Shu; Yang, Wei-Jun

    2008-01-01

    Background Metazoan mitochondrial genomes usually consist of the same 37 genes. Such genes contain useful information for phylogenetic analyses and evolution modelling. Although complete mitochondrial genomes have been determined for over 1,000 animals to date, hydrothermal vent species have, thus far, remained excluded due to the scarcity of collected specimens. Results The mitochondrial genome of the hydrothermal vent galatheid crab Shinkaia crosnieri is 15,182 bp in length, and is composed of 13 protein-coding genes, two ribosomal RNA genes and only 18 transfer RNA genes. The total AT content of the genome, as is typical for decapods, is 72.9%. We identified a non-coding control region of 327 bp according to its location and AT-richness. This is the smallest control region discovered in crustaceans so far. A mechanism of cytoplasmic tRNA import was addressed to compensate for the four missing tRNAs. The S. crosnieri mitogenome exhibits a novel arrangement of mitochondrial genes. We investigated the mitochondrial gene orders and found that at least six rearrangements from the ancestral pancrustacean (crustacean + hexapod) pattern have happened successively. The codon usage, nucleotide composition and bias show no substantial difference with other decapods. Phylogenetic analyses using the concatenated nucleotide and amino acid sequences of the 13 protein-coding genes prove consistent with the previous classification based upon their morphology. Conclusion The present study will supply considerable data of use for both genomic and evolutionary research on hydrothermal vent ecosystems. The mitochondrial genetic characteristics of decapods are sustained in this case of S. crosnieri despite the absence of several tRNAs and a number of dramatic rearrangements. Our results may provide evidence for the immigrating hypothesis about how vent species originate. PMID:18510775

  15. Analysis of the central nervous system transcriptome of the eastern rock lobster Sagmariasus verreauxi reveals its putative neuropeptidome.

    PubMed

    Ventura, Tomer; Cummins, Scott F; Fitzgibbon, Quinn; Battaglene, Stephen; Elizur, Abigail

    2014-01-01

    Neuropeptides have been discovered in many arthropod species including crustaceans. The nature of their biological function is well studied and varies from behavior modulation to physiological regulation of complex biochemical processes such as metabolism, molt and reproduction. Due to their key role in these fundamental processes, neuropeptides are often targeted for modulating these processes to align with market demands in commercially important species. We generated a comprehensive transcriptome of the eyestalk and brain of one of the few commercially important spiny lobster species in the southern Hemisphere, the Eastern rock lobster Sagmariasus verreauxi and mined it for novel neuropeptide and protein hormone-encoding transcripts. We then characterized the predicted mature hormones to verify their validity based on conserved motifs and features known from previously reported hormones. Overall, 37 transcripts which are predicted to encode mature full-length/partial peptides/proteins were identified, representing 21 peptide/protein families/subfamilies. All transcripts had high similarity to hormones that were previously characterized in other decapod crustacean species or, where absent in crustaceans, in other arthropod species. These included, in addition to other proteins previously described in crustaceans, prohormone-3 and prohormone-4 which were previously identified only in insects. A homolog of the crustacean female sex hormone (CFSH), recently found to be female-specific in brachyuran crabs was found to have the same levels of expression in both male and female eyestalks, suggesting that the CFSH female specificity is not conserved throughout decapod crustaceans. Digital gene expression showed that 24 out of the 37 transcripts presented in this study have significant changes in expression between eyestalk and brain. In some cases a trend of difference between males and females could be seen. Taken together, this study provides a comprehensive neuropeptidome of a commercially important crustacean species with novel peptides and protein hormones identified for the first time in decapods. PMID:24819537

  16. 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

  17. Transcriptome and Peptidome Characterisation of the Main Neuropeptides and Peptidic Hormones of a Euphausiid: The Ice Krill, Euphausia crystallorophias

    PubMed Central

    Toullec, Jean-Yves; Corre, Erwan; Bernay, Benoît; Thorne, Michael A. S.; Cascella, Kévin; Ollivaux, Céline; Henry, Joël; Clark, Melody S.

    2013-01-01

    Background The Ice krill, Euphausia crystallorophias is one of the species at the base of the Southern Ocean food chain. Given their significant contribution to the biomass of the Southern Ocean, it is vitally important to gain a better understanding of their physiology and, in particular, anticipate their responses to climate change effects in the warming seas around Antarctica. Methodology/Principal Findings Illumina sequencing was used to produce a transcriptome of the ice krill. Analysis of the assembled contigs via two different methods, produced 36 new pre-pro-peptides, coding for 61 neuropeptides or peptide hormones belonging to the following families: Allatostatins (A, B et C), Bursicon (? and ?), Crustacean Hyperglycemic Hormones (CHH and MIH/VIHs), Crustacean Cardioactive Peptide (CCAP), Corazonin, Diuretic Hormones (DH), the Eclosion Hormone (EH), Neuroparsin, Neuropeptide F (NPF), small Neuropeptide F (sNPF), Pigment Dispersing Hormone (PDH), Red Pigment Concentrating Hormone (RPCH) and finally Tachykinin. LC/MS/MS proteomics was also carried out on eyestalk extracts, which are the major site of neuropeptide synthesis in decapod crustaceans. Results confirmed the presence of six neuropeptides and six precursor-related peptides previously identified in the transcriptome analyses. Conclusions This study represents the first comprehensive analysis of neuropeptide hormones in a Eucarida non-decapod Malacostraca, several of which are described for the first time in a non-decapod crustacean. Additionally, there is a potential expansion of PDH and Neuropeptide F family members, which may reflect certain life history traits such as circadian rhythms associated with diurnal migrations and also the confirmation via mass spectrometry of several novel pre-pro-peptides, of unknown function. Knowledge of these essential hormones provides a vital framework for understanding the physiological response of this key Southern Ocean species to climate change and provides a valuable resource for studies into the molecular phylogeny of these organisms and the evolution of neuropeptide hormones. PMID:23990964

  18. Distribution of phyllosoma lobster larvae (Crustacea: Decapoda: Reptantia: Scyllaridea) in the Gulf of Mexico in relation to currents and recruitment potential 

    E-print Network

    Hammer, Richard Melvin

    1974-01-01

    OF MEXICO IN RFLATION TO CURRENTS AND RECRUITMLNT POTEFT1AL A Thesis by R1CHARD MELUIN 11AiKER Approved a" tg style snd conteot h a I m I (Head of Depattm t) by: (Memb (M emb er ) (Memb er) May 1974 Dj stribut ion of Phy Llosoma lobster Larvae... species of lobsters of the decapod crustacean s!!Per- family Scyllar idea are known to occur in the Gulf of Mexico, Caribbean Sea, and western Atlantic Ocean. Collection data are given for 15 adults collected from the Gulf of Mexico and Carib- bean Sea...

  19. Food web structure and seasonality of slope megafauna in the NW Mediterranean elucidated by stable isotopes: Relationship with available food sources

    NASA Astrophysics Data System (ADS)

    Papiol, V.; Cartes, J. E.; Fanelli, E.; Rumolo, P.

    2013-03-01

    The food-web structure and seasonality of the dominant taxa of benthopelagic megafauna (fishes and decapods) on the middle slope of the Catalan Sea (Balearic Basin, NW Mediterranean) were investigated using the carbon and nitrogen stable isotope ratios of 29 species. Macrofauna (infauna, suprabenthos and zooplankton) were also analysed as potential prey. Samples were collected on a seasonal basis from 600 to 1000 m depth between February 2007 and February 2008. The fishes and decapods were classified into feeding groups based on the literature: benthic feeders (including suprabenthos) and zooplankton feeders, the latter further separated into migratory and non-migratory species. Decapods exhibited depleted ?15N and enriched ?13C compared to fishes. Annual mean ?13C of fishes ranged from - 19.15‰ (Arctozenus risso) to - 16.65‰ (Phycis blennoides) and of ?15N from 7.27‰ (Lampanyctus crocodilus) to 11.31‰ (Nezumia aequalis). Annual mean values of ?13C of decapods were from - 18.94‰ (Sergestes arcticus) to - 14.78‰ (Pontophilus norvegicus), and of ?15N from 6.36‰ (Sergia robusta) to 9.72‰ (Paromola cuvieri). Stable isotopes distinguished well amongst the 3 feeding guilds established a priori, pointing to high levels of resource partitioning in deep-sea communities. The trophic structure of the community was a function of the position of predators along the benthic-pelagic gradient, with benthic feeders isotopically enriched relative to pelagic feeders. This difference allowed the identification of two food webs based on pelagic versus benthic consumption. Prey and predator sizes were also important in structuring the community. The most generalised seasonal pattern was ?13C depletion from winter to spring and summer, especially amongst migratory macroplankton feeders. This suggests greater consumption of pelagic prey, likely related with increases in pelagic production or with ontogenic migrations of organisms from mid-water to the Benthic Boundary Layer (BBL). ?15N enrichment was detected in periods of water column stratification, particularly amongst benthic feeder fishes. Megafauna relied on a single source of nutrition after peaks in surface production, presumably marine snow. Conversely, a larger array of food sources, probably from advection, sustained the community in periods of water column stratification. Benthic feeder ?13C values of both taxa were positively correlated with fluorescence measured 5 m above the seabed and negatively correlated with total organic carbon in the sediments, both being food sources for deposit feeding macroinfauna. Macroplankton feeder ?13C values were linked to environmental variables related to vertical transport from surface production, i.e. lipids and chlorophyll and their degradation products, likely due to their stronger reliance on sinking phytodetritus through consumption of planktonic prey.

  20. The VD1/RPD2 ?1-neuropeptide is highly expressed in the brain of cephalopod mollusks.

    PubMed

    Wollesen, Tim; Nishiguchi, Michele K; Seixas, Pedro; Degnan, Bernard M; Wanninger, Andreas

    2012-06-01

    In certain gastropod mollusks, the central neurons VD(1) and RPD(2) express a distinct peptide, the so-called VD(1)/RPD(2) ?1-neuropeptide. In order to test whether this peptide is also present in the complex cephalopod central nervous system (CNS), we investigated several octopod and squid species. In the adult decapod squid Idiosepius notoides the ?1-neuropeptide is expressed throughout the CNS, with the exception of the vertical lobe and the superior and inferior frontal lobes, by very few immunoreactive elements. Immunoreactive cell somata are particularly abundant in brain lobes and associated organs unique to cephalopods such as the subvertical, optic, peduncle, and olfactory lobes. The posterior basal lobes house another large group of immunoreactive cell somata. In the decapod Idiosepius notoides, the ?1-neuropeptide is first expressed in the olfactory organ, while in the octopod Octopus vulgaris it is first detected in the olfactory lobe. In prehatchlings of the sepiolid Euprymna scolopes as well as the squids Sepioteuthis australis and Loligo vulgaris, the ?1-neuropeptide is expressed in the periesophageal and posterior subesophageal mass. Prehatchlings of L. vulgaris express the ?1-neuropeptide in wide parts of the CNS, including the vertical lobe. ?1-neuropeptide expression in the developing CNS does not appear to be evolutionarily conserved across various cephalopod taxa investigated. Strong expression in different brain lobes of the adult squid I. notoides and prehatching L. vulgaris suggests a putative role as a neurotransmitter or neuromodulator in these species; however, electrophysiological evidence is still missing. PMID:22427117

  1. On the occurrence of Ctenocheles (Decapoda, Axiidea, Ctenochelidae) in the Bohemian Cretaceous Basin

    PubMed Central

    HYŽNÝ, MATÚŠ; VESELSKÁ, MARTINA KO?OVÁ; DVO?ÁK, PAVEL

    2015-01-01

    Because of close morphological affinities, fossil cheliped fragments of the ghost shrimp Ctenocheles (Decapoda, Axiidea, Ctenochelidae) can be easily misidentified as remains of different decapod crustacean taxa. Re-examination of the Cretaceous decapods deposited in the National Museum in Prague revealed that all supposed specimens of the lobster genus Oncopareia found in the Middle Coniacian calcareous claystones of the B?ezno Formation, including one of the Fritsch’s original specimens of Stenocheles parvulus, actually belong to Ctenocheles. This material together with newly collected specimens from the same locality, allowed for erection of a new species, Ctenocheles fritschi. Its major chela possesses a serrated ischium and ovoid, unarmed merus; therefore, it is considered a close relative of the extant C. collini and C. maorianus. Ctenocheles fritschi sp. nov. represents the first report on the occurrence of the genus from the Bohemian Cretaceous Basin. It is one of the oldest records of Ctenocheles and simultaneously one of the best preserved fossils of the genus reported to date. Confusing taxonomy of S. parvulus is reviewed and shortly discussed. PMID:25983568

  2. Bioaccumulation of trace metals in the brown shrimp Crangon crangon (Linnaeus, 1758) from the German Wadden Sea.

    PubMed

    Jung, K; Zauke, G-P

    2008-07-30

    The objective of the present study is to evaluate the suitability of the brown shrimp Crangon crangon (Linnaeus, 1758) from the German Wadden Sea as a biomonitor for the trace metals Cd, Pb, Cu, and Zn and to analyse whether the two-compartment model sensu OECD could be used as a predictive tool to assess environmental quality. The tested decapods accumulated Cd and Pb upon exposure and it was possible to estimate significant model parameters of two-compartment models, while they did not respond to waterborn Cu and Zn. Kinetic BCFs at theoretical equilibrium were 860 for Cd and 750 for Pb. A tentative estimation showed the following sensitivity of C. crangon to an increase of soluble metal exposure: 0.4 microg Cd l(-1) and 0.9 microg Pb l(-1). Available information can be used to quantify a measure of agreement or disagreement between bioaccumulation in various decapods. This can be regarded as an important step in the calibration of biomonitors, which is necessary to assess the potential for bioaccumulation on different temporal and geographical scales. PMID:18571744

  3. Age, Growth and Feeding Habits of the Brown Comber Serranus hepatus(Linnaeus, 1758) on the Cretan Shelf

    NASA Astrophysics Data System (ADS)

    Labropoulou, M.; Tserpes, G.; Tsimenides, N.

    1998-05-01

    Forty-five samples of the brown comber Serranus hepatuswere collected during experimental surveys carried out on a monthly basis (August 1990 to August 1992) along the Cretan continental shelf. A total of 1268 specimens 31-140 mm in total length were analysed. Growth was well described by both standard and seasonalized forms of the von Bertalanffy growth model and the computed parameters were L?;=152 mm, k=0·36, t0=-0·57. Feeding intensity was high throughout the study period and varied significantly among the age classes of fish examined. Stomach content analysis revealed that S. hepatusis carnivorous, feeding mainly on decapods. Diets did not vary seasonally; decapods were the most important prey throughout the year. However, the composition of the prey consumed varied considerably with predator age coupled with differences in mean prey sizes utilized by each age class. The mean weight of stomach contents increased significantly for older specimens, while the mean number of prey items decreased. Age-specific dietary selection was primarily a function of body size of the predator and appears to reduce intra-specific competition among the members of the different age classes. The results suggest that S. hepatusplays an important trophic role as a macrophagic carnivorous species on the Cretan continental shelf.

  4. Orcokinin peptides in developing and adult crustacean stomatogastric nervous systems and pericardial organs.

    PubMed

    Li, Lingjun; Pulver, Stefan R; Kelley, Wayne P; Thirumalai, Vatsala; Sweedler, Jonathan V; Marder, Eve

    2002-03-12

    The orcokinins are a family of neuropeptides recently isolated from several crustacean species. We found orcokinin-like immunoreactivity in the stomatogastric nervous systems and pericardial organs of three decapod crustacean species, Homarus americanus, Cancer borealis, and Panulirus interruptus. The neuropil of the stomatogastric ganglion was stained in adults of all three species as well as in embryonic and larval H. americanus. In H. americanus, the somata giving rise to this projection were found in the inferior ventricular nerve. Matrix-assisted laser desorption/ionization mass spectrometry mass profiling and sequencing with postsource decay led to the identification of six different orcokinin family peptides, including those previously described in other decapods and two novel shorter peptides. Application of exogenous [Ala(13)]orcokinin to the stomatogastric ganglion of H. americanus resulted in changes in the pyloric rhythm. Specifically, the number of lateral pyloric (LP) neuron spikes/burst decreased, and the phase of firing of the pyloric neurons was altered. Together, these data indicate that the orcokinins are likely to function as modulators of the crustacean stomatogastric ganglion. PMID:11840477

  5. Differential transcriptome analysis of the common shrimp Crangon crangon: special focus on the nuclear receptors and RNAi-related genes.

    PubMed

    Christiaens, Olivier; Delbare, Daan; Van Neste, Christophe; Cappelle, Kaat; Yu, Na; De Wilde, Ruben; Van Nieuwerburgh, Filip; Deforce, Dieter; Cooreman, Kris; Smagghe, Guy

    2015-02-01

    The decapod Crangon crangon is one of the most valuable European fisheries commodities. Despite its economic importance, little sequence data is available for this shrimp species. In this paper, we report the transcriptome sequencing for five different stages of C. crangon (early embryo, late embryo, larva, female adults and male adults) and the annotation and stage-specific expression analysis of nuclear receptors (NRs) and RNA interference (RNAi)-related genes. The NRs are transcription factors that play an essential role in growth, development, cell differentiation, molting/metamorphosis and reproduction, while the RNAi-related genes are very important for internal gene expression regulation and in antiviral defense. We discovered a NR in the female C. crangon which is either a very rapidly evolved homolog of HR10, or a novel NR altogether. This new NR could act as a biological marker for sex determination as it is not expressed in male adults. Most RNAi-related genes were present in C. crangon, proving that the requirements for successful RNAi is present in this decapod shrimp. RNAi-based applications in Crangon such as its use in functional genomics or as antiviral therapeutics could become very important in the near future. PMID:24971805

  6. A Comparative Analysis of Feeding and Trophic Level Ecology in Stingrays (Rajiformes; Myliobatoidei) and Electric Rays (Rajiformes: Torpedinoidei)

    PubMed Central

    Jacobsen, Ian P.; Bennett, Mike B.

    2013-01-01

    Standardised diets and trophic level (TL) estimates were calculated for 75 ray species from the suborders Myliobatoidei (67 spp.) and Torpedinoidei (8 spp.). Decapod crustaceans (31.71±3.92%) and teleost fishes (16.45±3.43%) made the largest contribution to the standardised diet of the Myliobatoidei. Teleost fishes (37.40±16.09%) and polychaete worms (31.96±14.22%) were the most prominent prey categories in the standardised diet of the suborder Torpedinoidei. Cluster analysis identified nine major trophic guilds the largest of which were decapod crustaceans (24 species), teleost fishes (11 species) and molluscs (11 species). Trophic level estimates for rays ranged from 3.10 for Potamotrygon falkneri to 4.24 for Gymnura australis, Torpedo marmorata and T. nobiliana. Secondary consumers with a TL <4.00 represented 84% of the species examined, with the remaining 12 species (16%) classified as tertiary consumers (TL ?4.00). Tertiary consumers included electric rays (Torpedo, 3 spp. and Hypnos, 1 sp.), butterfly rays (Gymnura, 4 spp.), stingrays (2 spp.) and Potamotrygonid stingrays (2 spp.). Feeding strategies were identified as the primary factor of influence with respect to Myliobatoidei and Torpedinoidei TL estimates with inter-family comparisons providing the greatest insight into Myliobatoidei and Torpedinoidei relationships. PMID:23936503

  7. Through the stomach of a predator: Regional patterns of forage in the diet of albacore tuna in the California Current System and metrics needed for ecosystem-based management

    NASA Astrophysics Data System (ADS)

    Glaser, Sarah M.; Waechter, Katrina E.; Bransome, Nicole C.

    2015-06-01

    Foraging habits of predators can reveal patterns in prey ecology and guide ecosystem-based management by informing species interactions. This study describes the diet habits of albacore tuna in three regions (north, central, south) of the California Current System (CCS) and estimates the total predation mortality imposed on twenty prey taxa. The northern CCS was defined by predation on decapods, euphausiids, anchovy and hake. The central CCS was defined by predation on squid, hake and Pacific saury. The southern CCS was defined by predation on anchovy. We estimate North Pacific albacore consumed each year, on average, 54,000 mt of decapods and euphausiids, 43,000 mt of cephalopods, 84,000 mt of juvenile hake, 1600 mt of myctophids, 21,000 mt of juvenile sardine, 10,000 mt of juvenile rockfishes, almost 43,000 mt of Pacific saury, and over 107,000 mt of juvenile anchovy. While variability in predation certainly exists, this and prior studies show that diet habits of albacore are fairly stable through time. The northern CCS appears to be a more significant source of energy for albacore. When designing ecosystem-based approaches to the management of CCS-based fisheries, we recommend that the forage contribution of saury, hake and anchovy to the albacore population be considered.

  8. A comparative analysis of feeding and trophic level ecology in stingrays (Rajiformes; Myliobatoidei) and electric rays (Rajiformes: Torpedinoidei).

    PubMed

    Jacobsen, Ian P; Bennett, Mike B

    2013-01-01

    Standardised diets and trophic level (T L) estimates were calculated for 75 ray species from the suborders Myliobatoidei (67 spp.) and Torpedinoidei (8 spp.). Decapod crustaceans (31.71 ± 3.92%) and teleost fishes (16.45 ± 3.43%) made the largest contribution to the standardised diet of the Myliobatoidei. Teleost fishes (37.40 ± 16.09%) and polychaete worms (31.96 ± 14.22%) were the most prominent prey categories in the standardised diet of the suborder Torpedinoidei. Cluster analysis identified nine major trophic guilds the largest of which were decapod crustaceans (24 species), teleost fishes (11 species) and molluscs (11 species). Trophic level estimates for rays ranged from 3.10 for Potamotrygon falkneri to 4.24 for Gymnura australis, Torpedo marmorata and T. nobiliana. Secondary consumers with a T L <4.00 represented 84% of the species examined, with the remaining 12 species (16%) classified as tertiary consumers (T L ? 4.00). Tertiary consumers included electric rays (Torpedo, 3 spp. and Hypnos, 1 sp.), butterfly rays (Gymnura, 4 spp.), stingrays (2 spp.) and Potamotrygonid stingrays (2 spp.). Feeding strategies were identified as the primary factor of influence with respect to Myliobatoidei and Torpedinoidei T L estimates with inter-family comparisons providing the greatest insight into Myliobatoidei and Torpedinoidei relationships. PMID:23936503

  9. Housekeeping Mutualisms: Do More Symbionts Facilitate Host Performance?

    PubMed Central

    Lemer, Sarah; Leray, Matthieu; Mills, Suzanne C.; Osenberg, Craig W.

    2012-01-01

    Mutualisms often involve one host supporting multiple symbionts, whose identity, density and intraguild interactions can influence the nature of the mutualism and performance of the host. However, the implications of multiple co-occurring symbionts on services to a host have rarely been quantified. In this study, we quantified effects of decapod symbionts on removal of sediment from their coral host. Our field survey showed that all common symbionts typically occur as pairs and never at greater abundances. Two species, the crab Trapezia serenei and the shrimp Alpheus lottini, were most common and co-occurred more often than expected by chance. We conducted a mesocosm experiment to test for effects of decapod identity and density on sediment removal. Alone, corals removed 10% of sediment, but removal increased to 30% and 48% with the presence of two and four symbionts, respectively. Per-capita effects of symbionts were independent of density and identity. Our results suggest that symbiont density is restricted by intraspecific competition. Thus, increased sediment removal from a coral host can only be achieved by increasing the number of species of symbionts on that coral, even though these species are functionally equivalent. Symbiont diversity plays a key role, not through added functionality but by overcoming density limitation likely imposed by intraspecific mating systems. PMID:22523536

  10. Putative Pacemakers in the Eyestalk and Brain of the Crayfish Procambarus clarkii Show Circadian Oscillations in Levels of mRNA for Crustacean Hyperglycemic Hormone

    PubMed Central

    Nelson-Mora, Janikua; Prieto-Sagredo, Julio; Loredo-Ranjel, Rosaura; Fanjul-Moles, María Luisa

    2013-01-01

    Crustacean hyperglycemic hormone (CHH) synthesizing cells in the optic lobe, one of the pacemakers of the circadian system, have been shown to be present in crayfish. However, the presence of CHH in the central brain, another putative pacemaker of the multi-oscillatory circadian system, of this decapod and its circadian transcription in the optic lobe and brain have yet to be explored. Therefore, using qualitative and quantitative PCR, we isolated and cloned a CHH mRNA fragment from two putative pacemakers of the multi-oscillatory circadian system of Procambarus clarkii, the optic lobe and the central brain. This CHH transcript synchronized to daily light-dark cycles and oscillated under dark, constant conditions demonstrating statistically significant daily and circadian rhythms in both structures. Furthermore, to investigate the presence of the peptide in the central brain of this decapod, we used immunohistochemical methods. Confocal microscopy revealed the presence of CHH-IR in fibers and cells of the protocerebral and tritocerebal clusters and neuropiles, particularly in some neurons located in clusters 6, 14, 15 and 17. The presence of CHH positive neurons in structures of P. clarkii where clock proteins have been reported suggests a relationship between the circadian clockwork and CHH. This work provides new insights into the circadian regulation of CHH, a pleiotropic hormone that regulates many physiological processes such as glucose metabolism and osmoregulatory responses to stress. PMID:24391849

  11. Environmental drivers of megafaunal assemblage composition and biomass distribution over mainland and insular slopes of the Balearic Basin (Western Mediterranean)

    NASA Astrophysics Data System (ADS)

    Fanelli, E.; Cartes, J. E.; Papiol, V.; López-Pérez, C.

    2013-08-01

    The influence of mesoscale physical and trophic variables on deep-sea megafauna, a scale of variation often neglected in deep-sea studies, is crucial for understanding their role in the ecosystem. Drivers of megafaunal assemblage composition and biomass distribution have been investigated in two contrasting areas of the Balearic basin in the NW Mediterranean: on the mainland slope (Catalonian coasts) and on the insular slope (North of Mallorca, Balearic Islands). An experimental bottom trawl survey was carried out during summer 2010, at stations in both sub-areas located between 450 and 2200 m water depth. Environmental data were collected simultaneously: near-bottom physical parameters, and the elemental and isotopic composition of sediments. Initially, data were analysed along the whole depth gradient, and then assemblages from the two areas were compared. Analysis of the trawls showed the existence of one group associated with the upper slope (US=450-690 m), another with the middle slope (MS=1000-1300 m) and a third with the lower slope (LS=1400-2200 m). Also, significant differences in the assemblage composition were found between mainland and insular slopes at MS. Dominance by different species was evident when the two areas were compared by SIMPER analysis. The greatest fish biomass was recorded in both areas at 1000-1300 m, a zone linked to minimum temperature and maximum O2 concentration on the bottom. Near the mainland, fish assemblages were best explained (43% of total variance, DISTLM analysis) by prey availability (gelatinous zooplankton biomass). On the insular slope, trophic webs seemed less complex and were based on vertical input of surface primary production. Decapods, which reached their highest biomass values on the upper slope, were correlated with salinity and temperature in both the areas. However, while hydrographic conditions (temperature and salinity) seemed to be the most important variables over the insular slope, resource availability (gelatinous zooplankton and Calocaris macandreae) predominated and explained 59% of decapod assemblage variation over the mainland slope. Both fish and decapods were linked to net primary production recorded over the mainland 3 months before sampling, while the delay between the input of food from the surface and fish abundance was only 1 month on the insular slope. Our results suggest that trophic relationships over insular slopes probably involve a shorter food chain than over mainland slopes and one that is likely more efficient in terms of energy transfer.

  12. Biorecovery of gold

    USGS Publications Warehouse

    Eisler, R.

    2003-01-01

    Recovery of ionic and metallic gold (Au) from a wide variety of solutions by selected species of bacteria, yeasts, fungi, algae, and higher plants is documented. Gold accumulations were up to 7.0 g/kg dry weight (DW) in various species of bacteria, 25.0 g/kg DW in freshwater algae, 84.0 g/kg DW in peat, and 100.0 g/kg DW in dried fungus mixed with keratinous material. Mechanisms of accumulation include oxidation, dissolution, reduction, leaching, and sorption. Uptake patterns are significantly modified by the physicochemical milieu. Crab exoskeletons accumulate up to 4.9 g Au/kg DW; however, gold accumulations in various tissues of living teleosts, decapod crustaceans, and bivalve molluscs are negligible.

  13. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (Pacific Northwest): Ghost shrimp and blue mud shrimp

    SciTech Connect

    Horning, S.; Sterling, A.; Smith, S.D.

    1989-01-01

    Species profiles are literature summaries of the taxonomy, morphology, range, life history, and environmental requirements of coastal aquatic species. The profiles are prepared to assist in environmental impact assessments. The ghost shrimp (Callianassa californiensis) and blue mud shrimp (Upogebia pugettensis) are common residents of intertidal mudflats of the Pacific Northwest, as well as of the entire West Coast of the contiguous United States. These species are decapod crustaceans, but not true shrimp. They are harvested as bait by recreational and commercial oyster-growing operations. Ghost shrimp larvae develop in summer in nearshore coastal waters and settle to the substrate surface, where they rapidly metamorphose; the life cycle of the blue mud shrimp is presumed to be similar. Both species spend their lives in burrows in the mudflat, where the ghost shrimp is primarily a deposit feeder and the blue mud shrimp is a suspension feeder.

  14. First report on vertical transmission of a plasmid DNA in freshwater prawn, Macrobrachium rosenbergii.

    PubMed

    Chowdhury, Labrechai Mog; Gireesh-Babu, P; Pavan-Kumar, A; Suresh Babu, P P; Chaudhari, Aparna

    2014-09-01

    Outbreak of WSSV disease is one of the major stumbling blocks in shrimp aquaculture. DNA vaccines have shown potential for mass scale vaccination owing to their stability, cost effectiveness and easy maintenance. Development of economically feasible delivery strategies remains to be a major challenge. This study demonstrates vertical transmission of a plasmid DNA in a decapod Macrobrachium rosenbergii for the first time. Females at three different maturation stages (immature, matured and berried) and mature males were injected with a plasmid DNA and allowed to spawn with untreated counterparts. Using specific primers the plasmid DNA could be amplified from the offspring of all groups except that of berried females. For this confirmation genomic DNA was isolated from 3 pools of 10 post larvae in each group. This presents an ideal strategy to protect young ones at zero stress. PMID:24933022

  15. Physiological responses of estuarine animals to cadmium pollution

    NASA Astrophysics Data System (ADS)

    Theede, H.

    1980-03-01

    Toxic effects of cadmium contamination may be observed at all levels of organismic organization. In estuarine areas the sensitivity of euryhaline species to acute Cd toxicity is strongly modified by various abiotic factors, whereas long-term threshold values are less dependent on environmental parameters. Experiments with larval stages of the mollusc Mytilus edulis reveal that Cd effects on life functions such as development and growth are differentially modified by temperature and salinity. High Cd concentrations can be accumulated by adult bivalves of coastal areas without signs of physiological damage. Mechanisms of heavy-metal detoxication in these molluscs seem to be quite different from those known to exist in vertebrates. Among decapod crustaceans, stenoecous species tend to exhibit higher rates of Cd uptake than euryoecous ones. Rates of Cd uptake and of accumulation depend on external and internal factors. In adult Nereis succinea individuals sublethal Cd effects have been recorded on growth and food conversion (in terms of energy content).

  16. The Early Miocene Cape Melville Formation fossil assemblage and the evolution of modern Antarctic marine communities

    NASA Astrophysics Data System (ADS)

    Whittle, Rowan J.; Quaglio, Fernanda; Griffiths, Huw J.; Linse, Katrin; Crame, J. Alistair

    2014-01-01

    The fossil community from the Early Miocene Cape Melville Formation (King George Island, Antarctica) does not show the archaic retrograde nature of modern Antarctic marine communities, despite evidence, such as the presence of dropstones, diamictites and striated rocks, that it was deposited in a glacial environment. Unlike modern Antarctic settings, and the upper units of the Eocene La Meseta Formation on Seymour Island, Antarctica, which are 10 million years older, the Cape Melville Formation community is not dominated by sessile suspension feeding ophiuroids, crinoids or brachiopods. Instead, it is dominated by infaunal bivalves, with a significant component of decapods, similar to present day South American settings. It is possible that the archaic retrograde structure of the modern community did not fully evolve until relatively recently, maybe due to factors such as further cooling and isolation of the continent leading to glaciations, which resulted in a loss of shallow shelf habitats.

  17. North Sea ecosystem change from swimming crabs to seagulls.

    PubMed

    Luczak, C; Beaugrand, G; Lindley, J A; Dewarumez, J-M; Dubois, P J; Kirby, R R

    2012-10-23

    A recent increase in sea temperature has established a new ecosystem dynamic regime in the North Sea. Climate-induced changes in decapods have played an important role. Here, we reveal a coincident increase in the abundance of swimming crabs and lesser black-backed gull colonies in the North Sea, both in time and in space. Swimming crabs are an important food source for lesser black-backed gulls during the breeding season. Inhabiting the land, but feeding mainly at sea, lesser black-backed gulls provide a link between marine and terrestrial ecosystems, since the bottom-up influence of allochthonous nutrient input from seabirds to coastal soils can structure the terrestrial food web. We, therefore, suggest that climate-driven changes in trophic interactions in the marine food web may also have ensuing ramifications for the coastal ecology of the North Sea. PMID:22764111

  18. The distribution and relative abundance of Nematopsis spp., as found in Crassostrea virginica (Gmelin) in the Galveston Bay area 

    E-print Network

    Anderson, Roger Dean

    1969-01-01

    - red at three locations. Of the 400 oysters studied, 99Fo were infected hy N. t 9, 99'/ re ' f t d by N. Nyth 9ht'. d 3'/ * infected by N. sp. Wide differences in levels of infection were found in the samples. This was attributed to differences... of oysters infected with 23 ~N* t pp. 25 3 Intensity of infection with reference to ecological parameters 28 4 Dt h g f y t hyC t ~t'c 5 Exp ' anti'f t'c fC t Eh Ep ' tlif*tl fc te ~tc 6 Experimental infection of decapod hosts . 30 32 33 35 y EN...

  19. Novel Protocol for the Chemical Synthesis of Crustacean Hyperglycemic Hormone Analogues — An Efficient Experimental Tool for Studying Their Functions

    PubMed Central

    Mosco, Alessandro; Zlatev, Vientsislav; Guarnaccia, Corrado; Pongor, Sándor; Campanella, Antonella; Zahariev, Sotir; Giulianini, Piero G.

    2012-01-01

    The crustacean Hyperglycemic Hormone (cHH) is present in many decapods in different isoforms, whose specific biological functions are still poorly understood. Here we report on the first chemical synthesis of three distinct isoforms of the cHH of Astacus leptodactylus carried out by solid phase peptide synthesis coupled to native chemical ligation. The synthetic 72 amino acid long peptide amides, containing L- or D-Phe3 and (Glp1, D-Phe3) were tested for their biological activity by means of homologous in vivo bioassays. The hyperglycemic activity of the D-isoforms was significantly higher than that of the L-isoform, while the presence of the N-terminal Glp residue had no influence on the peptide activity. The results show that the presence of D-Phe3 modifies the cHH functionality, contributing to the diversification of the hormone pool. PMID:22253873

  20. The feeding habits of three Mediterranean sea anemone species, Anemonia viridis (Forskĺl), Actinia equina (Linnaeus) and Cereus pedunculatus (Pennant)

    NASA Astrophysics Data System (ADS)

    Chintiroglou, Ch.; Koukouras, A.

    1992-03-01

    The feeding habits of the Mediterranean sea anemones Cereus pedunculatus, Actinia equina and Anemonia viridis were examined mainly by analysing their coelenteron contents. The three species are opportunistic omnivorous suspension feeders. Main source of food for A. viridis and C. pedunculatus are crustaceans (mainly amphipods and decapods, respectively), while for the midlittoral species A. equina, it is organic detritus. Using the same method, the temporal and spatial changes in the diet of A. viridis were examined. During the whole year, crustaceans seem to be the main source of food for A. viridis. The diet composition of this species, however, differs remarkably in space, possibly reflecting the different composition of the macrobenthic organismic assemblages in different areas. The data collected are compared with the limited bibliographical information.

  1. Food of freshwater drum in western Lake Erie

    USGS Publications Warehouse

    Bur, Michael T.

    1982-01-01

    The abundance of freshwater drum (Aplodinotus grunniens) suggests they play an important role in the Lake Erie ecosystem. Our analysis of freshwater drum digestive tracts and macrobenthic samples collected from western Lake Erie indicates that drum were selective feeders. Planktonic cladocerans and larval midges (Chironomidae) were the primary prey organisms eaten by drum. Young-of-the-year fed mostly on cladocerans, while yearling and older drum ate both cladocerans and midge larvae. Decapods, pelecypods, and fish were found only in the digestive tracts of drum longer than 250 mm. While the most abundant organisms in benthic samples were cladocerans (ephippial) and oligochaetes (89.5% by number), they constituted less than 1% of the diet. An evaluation of food selectivity, using Ivlev's index of electivity for benthic organisms, indicated that adult drum preferred midges to any other benthic food.

  2. Novel protocol for the chemical synthesis of crustacean hyperglycemic hormone analogues--an efficient experimental tool for studying their functions.

    PubMed

    Mosco, Alessandro; Zlatev, Vientsislav; Guarnaccia, Corrado; Pongor, Sándor; Campanella, Antonella; Zahariev, Sotir; Giulianini, Piero G

    2012-01-01

    The crustacean Hyperglycemic Hormone (cHH) is present in many decapods in different isoforms, whose specific biological functions are still poorly understood. Here we report on the first chemical synthesis of three distinct isoforms of the cHH of Astacus leptodactylus carried out by solid phase peptide synthesis coupled to native chemical ligation. The synthetic 72 amino acid long peptide amides, containing L- or D-Pheł and (Glpą, D-Pheł) were tested for their biological activity by means of homologous in vivo bioassays. The hyperglycemic activity of the D-isoforms was significantly higher than that of the L-isoform, while the presence of the N-terminal Glp residue had no influence on the peptide activity. The results show that the presence of D-Pheł modifies the cHH functionality, contributing to the diversification of the hormone pool. PMID:22253873

  3. Exuviotrophic apostome ciliates from crustaceans of St. Andrew Bay, Florida, and a description of Gymnodinioides kozloffi n. sp.

    PubMed

    Landers, Stephen C

    2004-01-01

    Gymnodinioides kozloffi n. sp. is described from the eelgrass broken-back shrimp Hippolyte zostericola. The species is distinct from others in the apostome genus Gymnodinioides in that the trophont ciliature has a small group of kinetosomes located to the right of Kinety 9a, and Kinety 1 and 2 are divided. Other apostome morphologies are described from many decapod crustaceans from St. Andrew Bay, Florida, including Gymnodinioides inkystans, Hyalophysa chattoni, and variants of both H. chattoni and G. kozloffi. All of these apostome ciliates are exuviotrophic, found feeding on exuvial fluid within the exoskeleton of the host after ecdysis. The hosts surveyed for this study are the following: Callinectes sapidus, Eurypanopeus depressus, Hippolyte zostericola, Farfantepenaeus spp., Palaemonetes intermedius, Palaemon floridanus, Portunus spp., Tozeuma carolinense, and Sicyonia laevigata, which revealed a number of new host-apostome records. PMID:15666721

  4. The 'ventral organs' of Pycnogonida (Arthropoda) are neurogenic niches of late embryonic and post-embryonic nervous system development.

    PubMed

    Brenneis, Georg; Scholtz, Gerhard

    2014-01-01

    Early neurogenesis in arthropods has been in the focus of numerous studies, its cellular basis, spatio-temporal dynamics and underlying genetic network being by now comparably well characterized for representatives of chelicerates, myriapods, hexapods and crustaceans. By contrast, neurogenesis during late embryonic and/or post-embryonic development has received less attention, especially in myriapods and chelicerates. Here, we apply (i) immunolabeling, (ii) histology and (iii) scanning electron microscopy to study post-embryonic ventral nerve cord development in Pseudopallene sp., a representative of the sea spiders (Pycnogonida), the presumable sister group of the remaining chelicerates. During early post-embryonic development, large neural stem cells give rise to additional ganglion cell material in segmentally paired invaginations in the ventral ectoderm. These ectodermal cell regions - traditionally designated as 'ventral organs' - detach from the surface into the interior and persist as apical cell clusters on the ventral ganglion side. Each cluster is a post-embryonic neurogenic niche that features a tiny central cavity and initially still houses larger neural stem cells. The cluster stays connected to the underlying ganglionic somata cortex via an anterior and a posterior cell stream. Cell proliferation remains restricted to the cluster and streams, and migration of newly produced cells along the streams seems to account for increasing ganglion cell numbers in the cortex. The pycnogonid cluster-stream-systems show striking similarities to the life-long neurogenic system of decapod crustaceans, and due to their close vicinity to glomerulus-like neuropils, we consider their possible involvement in post-embryonic (perhaps even adult) replenishment of olfactory neurons - as in decapods. An instance of a potentially similar post-embryonic/adult neurogenic system in the arthropod outgroup Onychophora is discussed. Additionally, we document two transient posterior ganglia in the ventral nerve cord of Pseudopallene sp. and evaluate this finding in light of the often discussed reduction of a segmented 'opisthosoma' during pycnogonid evolution. PMID:24736377

  5. Phylogenetic relationship among genera of Polymorphidae (Acanthocephala), inferred from nuclear and mitochondrial gene sequences.

    PubMed

    García-Varela, Martín; Pérez-Ponce de León, Gerardo; Aznar, Francisco J; Nadler, Steven A

    2013-08-01

    Acanthocephalans of the family Polymorphidae Meyer, 1931 are obligate endoparasites with complex life cycles. These worms use vertebrates (marine mammals, fish-eating birds and waterfowl) as definitive hosts and invertebrates (amphipods, decapods and euphausiids) as intermediate hosts to complete their life cycle. Polymorphidae has a wordwide distribution, containing 12 genera, with approximately 127 species. The family is diagnosed by having a spinose trunk, bulbose proboscis, double-walled proboscis receptacle, and usually four to eight tubular cement glands. To conduct a phylogenetic analysis, in the current study sequences of the small (18S) and large-subunit (28S) ribosomal RNA, and cytochrome c oxidase subunit 1 (cox 1) were generated for 27 taxa representing 10 of 12 genera of Polymorphidae, plus three additional species of acanthocephalans that were used as outgroups. Maximum likelihood (ML), maximum parsimony (MP), and Bayesian analyses were conducted on a combined nuclear rRNA (18S+28S) data set and on a concatenated dataset of nuclear plus one mitochondrial gene (18S+28S+cox 1). Phylogenetic analyses inferred with the concatenated dataset of three genes support the monophyly of nine genera (Andracantha, Corynosoma, Bolbosoma, Profilicollis, Pseudocorynosoma, Southwellina, Arhythmorhynchus, Hexaglandula and Ibirhynchus). However, the four sampled species of Polymorphus were nested within several clades, indicating that these species do not share a common ancestor, requiring further taxonomic revision using phylogenetic systematics, and reexamination of morphological and ecological data. By mapping definitive and intermediate host association onto the resulting cladogram, we observe that aquatic birds were the ancestral definitive hosts for the family with a secondary colonization and diversification to marine mammals. Whereas amphipods were ancestral intermediate hosts and that the association with decapods represent episodes of secondary colonization that arose several times during the evolutionary history of the family. Our results are useful to start testing hypothesis about the evolutionary history of this highly diverse family of acanthocephalans. PMID:23567022

  6. Animal behavior frozen in time: gregarious behavior of Early Jurassic lobsters within an ammonoid body chamber.

    PubMed

    Klompmaker, Adiël A; Fraaije, René H B

    2012-01-01

    Direct animal behavior can be inferred from the fossil record only in exceptional circumstances. The exceptional mode of preservation of ammonoid shells in the Posidonia Shale (Lower Jurassic, lower Toarcian) of Dotternhausen in southern Germany, with only the organic periostracum preserved, provides an excellent opportunity to observe the contents of the ammonoid body chamber because this periostracum is translucent. Here, we report upon three delicate lobsters preserved within a compressed ammonoid specimen of Harpoceras falciferum. We attempt to explain this gregarious behavior. The three lobsters were studied using standard microscopy under low angle light. The lobsters belong to the extinct family of the Eryonidae; further identification was not possible. The organic material of the three small lobsters is preserved more than halfway into the ammonoid body chamber. The lobsters are closely spaced and are positioned with their tails oriented toward each other. The specimens are interpreted to represent corpses rather than molts. The lobsters probably sought shelter in preparation for molting or against predators such as fish that were present in Dotternhausen. Alternatively, the soft tissue of the ammonoid may have been a source of food that attracted the lobsters, or it may have served as a long-term residency for the lobsters (inquilinism). The lobsters represent the oldest known example of gregariousness amongst lobsters and decapods in the fossil record. Gregarious behavior in lobsters, also known for extant lobsters, thus developed earlier in earth's history than previously known. Moreover, this is one of the oldest known examples of decapod crustaceans preserved within cephalopod shells. PMID:22412846

  7. Crustacean hyperglycemic hormones of two cold water crab species, Chionoecetes opilio and C. japonicus: isolation of cDNA sequences and localization of CHH neuropeptide in eyestalk ganglia.

    PubMed

    Chung, J Sook; Ahn, I S; Yu, O H; Kim, D S

    2015-04-01

    Crustacean hyperglycemic hormone (CHH) is primarily known for its prototypical function in hyperglycemia which is induced by the release of CHH. The CHH release takes place as an adaptive response to the energy demands of the animals experiencing stressful environmental, physiological or behavioral conditions. Although >63 decapod CHH nucleotide sequences are known (GenBank), the majority of them is garnered from the species inhabiting shallow and warm water. In order to understand the adaptive role of CHH in Chionoecetes opilio and Chionoecetes japonicus inhabiting deep water environments, we first aimed for the isolation of the full-length cDNA sequence of CHH from the eyestalk ganglia of C. opilio (ChoCHH) and C. japonicus (ChjCHH) using degenerate PCR and 5' and 3' RACE. Cho- and ChjCHH cDNA sequences are identical in 5' UTR and ORF with 100% sequence identity of the putative 138aa of preproCHHs. The length of 3' UTR ChjCHH cDNA sequence is 39 nucleotides shorter than that of ChoCHH. This is the first report in decapod crustaceans that two different species have the identical sequence of CHH. ChoCHH expression increases during embryogenesis of C. opilio and is significantly higher in adult males and females. C. japonicus males have slightly higher ChjCHH expression than C. opilio males, but no statistical difference. In both species, the immunostaining intensity of CHH is stronger in the sinus gland than that of X-organ cells. Future studies will enable us to gain better understanding of the comparative metabolic physiology and endocrinology of cold, deep water species of Chionoecetes spp. PMID:25224573

  8. The effects of serotonin, dopamine, gonadotropin-releasing hormones, and corazonin, on the androgenic gland of the giant freshwater prawn, Macrobrachium rosenbergii.

    PubMed

    Siangcham, Tanapan; Tinikul, Yotsawan; Poljaroen, Jaruwan; Sroyraya, Morakot; Changklungmoa, Narin; Phoungpetchara, Ittipon; Kankuan, Wilairat; Sumpownon, Chanudporn; Wanichanon, Chaitip; Hanna, Peter J; Sobhon, Prasert

    2013-11-01

    Neurotransmitters and neurohormones are agents that control gonad maturation in decapod crustaceans. Of these, serotonin (5-HT) and dopamine (DA) are neurotransmitters with known antagonist roles in female reproduction, whilst gonadotropin-releasing hormones (GnRHs) and corazonin (Crz) are neurohormones that exercise both positive and negative controls in some invertebrates. However, the effects of these agents on the androgenic gland (AG), which controls testicular maturation and male sex development in decapods, via insulin-like androgenic gland hormone (IAG), are unknown. Therefore, we set out to assay the effects of 5-HT, DA, l-GnRH-III, oct-GnRH and Crz, on the AG of small male Macrobrachium rosenbergii (Mr), using histological studies, a BrdU proliferative cell assay, immunofluorescence of Mr-IAG, and ELISA of Mr-IAG. The results showed stimulatory effects by 5-HT and l-GnRH-III through significant increases in AG size, proliferation of AG cells, and Mr-IAG production (P<0.05). In contrast, DA and Crz caused inhibitory effects on the AG through significant decreases in AG size, proliferation of AG cells, and Mr-IAG production (P<0.05). Moreover, the prawns treated with Crz died before day 16 of the experimental period. We propose that 5-HT and certain GnRHs can be now used to stimulate reproduction in male M. rosenbergii, as they induce increases in AG and testicular size, IAG production, and spermatogenesis. The mechanisms by which these occur are part of our on-going research. PMID:23867230

  9. Auswirkungen einer Pipeline-Verlegung auf das marine Benthos im Tidebecken von Baltrum-Langeoog

    NASA Astrophysics Data System (ADS)

    van Bernem, K. H.

    1999-12-01

    In order to investigate possible effects on benthic communities resulting from the landfall of the “EU-ROPIPE” gas pipeline in areas of the Wadden Sea National Park of Lower Saxony the following seasonal surveys were carried out by the GKSS-Research-Centre during 1993 1997: a) Assessment of species number and abundance of subtidal and intertidal macrofauna, b) Intertidal documentation of demersal fish and decapod crab stocks, c) Intertidal assessment of species composition and abundance of microalgae. Sublittoral sampling was mainly carried out by bottom-grabs and box-dredges at about 120 locations recorded by GPS. Sediment cores of intertidal benthic communities at 6 locations were processed for macrofauna and microalgae. Species numbers and abundances of sublittoral benthic macrofauna decreased during 1994 as well in those areas directly affected as well as in areas 500 to 1000m removed from the construction activities. Most notably, the relatively high species richness of a hard-bottom community, rare in Wadden Sea areas, was strongly disturbed. During the same period the spatial distribution and abundance of intertidal filter feeders decreased as well as the abundance of vagile predating polychaetes and amphipods at locations situated near low tide level. A local stock of the low dispersive Goby ( Pomatoschistus microps) was nearly totally destroyed. Decreases in the abundances of juvenile Plaice ( Pleuronectes platessa) and decapod crabs ( Crangon crangon, Carcinus maenas) could only be shown during July/October 1994 in those areas of working activities which were directly connected to the tidal migration paths of these species. During 1994/95 numbers and abundances of diatom species prefering fine grained sediments with a high amount of organic material increased significantly. A recovery started immediately after conclusion of the refilling measures in 1995. A complete documentation of the community-resilience, however, was masked by fluctuations following the ice-winter in 1995/96.

  10. An evolutionary analysis of flightin reveals a conserved motif unique and widespread in Pancrustacea.

    PubMed

    Soto-Adames, Felipe N; Alvarez-Ortiz, Pedro; Vigoreaux, Jim O

    2014-01-01

    Flightin is a thick filament protein that in Drosophila melanogaster is uniquely expressed in the asynchronous, indirect flight muscles (IFM). Flightin is required for the structure and function of the IFM and is indispensable for flight in Drosophila. Given the importance of flight acquisition in the evolutionary history of insects, here we study the phylogeny and distribution of flightin. Flightin was identified in 69 species of hexapods in classes Collembola (springtails), Protura, Diplura, and insect orders Thysanura (silverfish), Dictyoptera (roaches), Orthoptera (grasshoppers), Pthiraptera (lice), Hemiptera (true bugs), Coleoptera (beetles), Neuroptera (green lacewing), Hymenoptera (bees, ants, and wasps), Lepidoptera (moths), and Diptera (flies and mosquitoes). Flightin was also found in 14 species of crustaceans in orders Anostraca (water flea), Cladocera (brine shrimp), Isopoda (pill bugs), Amphipoda (scuds, sideswimmers), and Decapoda (lobsters, crabs, and shrimps). Flightin was not identified in representatives of chelicerates, myriapods, or any species outside Pancrustacea (Tetraconata, sensu Dohle). Alignment of amino acid sequences revealed a conserved region of 52 amino acids, referred herein as WYR, that is bound by strictly conserved tryptophan (W) and arginine (R) and an intervening sequence with a high content of tyrosines (Y). This motif has no homologs in GenBank or PROSITE and is unique to flightin and paraflightin, a putative flightin paralog identified in decapods. A third motif of unclear affinities to pancrustacean WYR was observed in chelicerates. Phylogenetic analysis of amino acid sequences of the conserved motif suggests that paraflightin originated before the divergence of amphipods, isopods, and decapods. We conclude that flightin originated de novo in the ancestor of Pancrustacea > 500 MYA, well before the divergence of insects (~400 MYA) and the origin of flight (~325 MYA), and that its IFM-specific function in Drosophila is a more recent adaptation. Furthermore, we propose that WYR represents a novel myosin coiled-coil binding motif. PMID:24271855

  11. A role for oxygen delivery and extracellular magnesium in limiting cold tolerance of the sub-antarctic stone crab Paralomis granulosa?

    PubMed

    Wittmann, Astrid C; Pörtner, Hans O; Sartoris, Franz J

    2012-01-01

    A low capacity for regulation of extracellular Mg(2+) has been proposed to exclude reptant marine decapod crustaceans from temperatures below 0°C and thus to exclude them from the high Antarctic. To test this hypothesis and to elaborate the underlying mechanisms in the most cold-tolerant reptant decapod family of the sub-Antarctic, the Lithodidae, thermal tolerance was determined in the crab Paralomis granulosa (Decapoda, Anomura, Lithodidae) using an acute stepwise temperature protocol (-1°, 1°, 4°, 7°, 10°, and 13°C). Arterial and venous oxygen partial pressures (Po(2)) in hemolymph, heartbeat and ventilation beat frequencies, and hemolymph cation composition were measured at rest and after a forced activity (righting) trial. Scopes for heartbeat and ventilation beat frequencies and intermittent heartbeat and scaphognathite beat rates at rest were evaluated. Hemolymph [Mg(2+)] was experimentally reduced from 30 mmol L(-1) to a level naturally observed in Antarctic caridean shrimps (12 mmol L(-1)) to investigate whether the animals remain more active and tolerant to cold (-1°, 1°, and 4°C). In natural seawater, righting speed was significantly slower at -1° and 13°C, compared with acclimation temperature (4°C). Arterial and venous hemolymph Po(2) increased in response to cooling even though heartbeat and ventilation beat frequencies as well as scopes decreased. At rest, ionic composition of the hemolymph was not affected by temperature. Activity induced a significant increase in hemolymph [K(+)] at -1° and 1°C. Reduction of hemolymph [Mg(2+)] did not result in an increase in activity, an increase in heartbeat and ventilation beat frequencies, or a shift in thermal tolerance to lower temperatures. In conclusion, oxygen delivery in this cold-water crustacean was not acutely limiting cold tolerance, and animals may have been constrained more by their functional capacity and motility. In contrast to earlier findings in temperate and subpolar brachyuran crabs, these constraints remained insensitive to changing Mg(2+) levels. PMID:22494984

  12. The ‘Ventral Organs’ of Pycnogonida (Arthropoda) Are Neurogenic Niches of Late Embryonic and Post-Embryonic Nervous System Development

    PubMed Central

    Brenneis, Georg; Scholtz, Gerhard

    2014-01-01

    Early neurogenesis in arthropods has been in the focus of numerous studies, its cellular basis, spatio-temporal dynamics and underlying genetic network being by now comparably well characterized for representatives of chelicerates, myriapods, hexapods and crustaceans. By contrast, neurogenesis during late embryonic and/or post-embryonic development has received less attention, especially in myriapods and chelicerates. Here, we apply (i) immunolabeling, (ii) histology and (iii) scanning electron microscopy to study post-embryonic ventral nerve cord development in Pseudopallene sp., a representative of the sea spiders (Pycnogonida), the presumable sister group of the remaining chelicerates. During early post-embryonic development, large neural stem cells give rise to additional ganglion cell material in segmentally paired invaginations in the ventral ectoderm. These ectodermal cell regions – traditionally designated as ‘ventral organs’ – detach from the surface into the interior and persist as apical cell clusters on the ventral ganglion side. Each cluster is a post-embryonic neurogenic niche that features a tiny central cavity and initially still houses larger neural stem cells. The cluster stays connected to the underlying ganglionic somata cortex via an anterior and a posterior cell stream. Cell proliferation remains restricted to the cluster and streams, and migration of newly produced cells along the streams seems to account for increasing ganglion cell numbers in the cortex. The pycnogonid cluster-stream-systems show striking similarities to the life-long neurogenic system of decapod crustaceans, and due to their close vicinity to glomerulus-like neuropils, we consider their possible involvement in post-embryonic (perhaps even adult) replenishment of olfactory neurons – as in decapods. An instance of a potentially similar post-embryonic/adult neurogenic system in the arthropod outgroup Onychophora is discussed. Additionally, we document two transient posterior ganglia in the ventral nerve cord of Pseudopallene sp. and evaluate this finding in light of the often discussed reduction of a segmented ‘opisthosoma’ during pycnogonid evolution. PMID:24736377

  13. Evolution and phylogeny of the mud shrimps (Crustacea: Decapoda) revealed from complete mitochondrial genomes

    PubMed Central

    2012-01-01

    Background The evolutionary history and relationships of the mud shrimps (Crustacea: Decapoda: Gebiidea and Axiidea) are contentious, with previous attempts revealing mixed results. The mud shrimps were once classified in the infraorder Thalassinidea. Recent molecular phylogenetic analyses, however, suggest separation of the group into two individual infraorders, Gebiidea and Axiidea. Mitochondrial (mt) genome sequence and structure can be especially powerful in resolving higher systematic relationships that may offer new insights into the phylogeny of the mud shrimps and the other decapod infraorders, and test the hypothesis of dividing the mud shrimps into two infraorders. Results We present the complete mitochondrial genome sequences of five mud shrimps, Austinogebia edulis, Upogebia major, Thalassina kelanang (Gebiidea), Nihonotrypaea thermophilus and Neaxius glyptocercus (Axiidea). All five genomes encode a standard set of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a putative control region. Except for T. kelanang, mud shrimp mitochondrial genomes exhibited rearrangements and novel patterns compared to the pancrustacean ground pattern. Each of the two Gebiidea species (A. edulis and U. major) and two Axiidea species (N. glyptocercus and N. thermophiles) share unique gene order specific to their infraorders and analyses further suggest these two derived gene orders have evolved independently. Phylogenetic analyses based on the concatenated nucleotide and amino acid sequences of 13 protein-coding genes indicate the possible polyphyly of mud shrimps, supporting the division of the group into two infraorders. However, the infraordinal relationships among the Gebiidea and Axiidea, and other reptants are poorly resolved. The inclusion of mt genome from more taxa, in particular the reptant infraorders Polychelida and Glypheidea is required in further analysis. Conclusions Phylogenetic analyses on the mt genome sequences and the distinct gene orders provide further evidences for the divergence between the two mud shrimp infraorders, Gebiidea and Axiidea, corroborating previous molecular phylogeny and justifying their infraordinal status. Mitochondrial genome sequences appear to be promising markers for resolving phylogenetic issues concerning decapod crustaceans that warrant further investigations and our present study has also provided further information concerning the mt genome evolution of the Decapoda. PMID:23153176

  14. Variability of coastal suprabenthic assemblages from sandy beaches of the Caribbean coast of Venezuela.

    PubMed

    Ortega, Ileana; Martín, Alberto; Díaz, Yusbelly J

    2014-06-01

    The suprabenthos or hyperbenthos is the macrofaunal assemblage of small-sized organisms that interact for some time in the benthic boundary layer. Information about the taxonomic composition and role of suprabenthic species, especially in littoral zones, is scarce and scattered. This work attempts to contribute alleviate this problem. We analyze the temporal and spatial variations of suprabenthic assemblages in the swash-zone from four beaches of the littoral coast of Venezuela. For each beach, two sites were chosen, and special attention was given to water and sediment characteristics. 12 environmental variables were measured: Dissolved oxygen, oxygen saturation percentage, pH, salinity, surface temperature, total, organic and inorganic suspended solids, total organic carbon, organic matter in sediment, grain size of sediment, and amount of dragged material of sample. All faunal samples were taken on a monthly basis during 2011; these were extracted using a manual suprabenthic sledge towed parallel to the shoreline. Samples were sorted and identified to their lowest possible taxonomic level. A total of 24 141 specimens (mean abundance: 26.16 +/- 55.35 ind./m2) belonging to 21 taxonomic groups were identified. Analysis suggests that seasonality does not explain observed changes either in fauna or environmental variables. It was found that suprabenthic assemblages, total suprabenthos density, richness and environmental variables changed in a dissimilar fashion between months and beaches. The most frequent groups were amphipods and decapods; and at the species/categories level post-larval shrimp (Penaeidae), Grapsidae crab megalopae and Arenaeus cribarius megalopae were common. Dissimilarity between months in each beach was primarily explained by the abundance of amphipods, ctenophores, decapods and mysids. For particular months and selected beaches very high abundances of ctenophores were found. This group dominated the sample even though it is not usually a representative group in suprabenthos. Samples showed low correlations between suprabenthos and environmental variables. A somewhat stronger correlation could be established between water characteristics and dragged material abundance. The studied suprabenthos assemblage was found to have high taxa richness and very dynamic behaviour at spatial and temporal scale. Further analysis suggested that there is no evident pattern of distribution and that causality can not be directly attributed to temporal variation only. Possibly there is an influence of a synergy of environmentals or biological factors, rather than a single variable. The species Americamysis bahia and Americamysis taironana are reported for the first time in Venezuela. This study represents the first ecological research of the suprabenthos in the Caribbean region. PMID:25102634

  15. In hot and cold water: differential life-history traits are key to success in contrasting thermal deep-sea environments.

    PubMed

    Marsh, Leigh; Copley, Jonathan T; Tyler, Paul A; Thatje, Sven

    2015-07-01

    Few species of reptant decapod crustaceans thrive in the cold-stenothermal waters of the Southern Ocean. However, abundant populations of a new species of anomuran crab, Kiwa tyleri, occur at hydrothermal vent fields on the East Scotia Ridge. As a result of local thermal conditions at the vents, these crabs are not restricted by the physiological limits that otherwise exclude reptant decapods south of the polar front. We reveal the adult life history of this species by piecing together variation in microdistribution, body size frequency, sex ratio, and ovarian and embryonic development, which indicates a pattern in the distribution of female Kiwaidae in relation to their reproductive development. High-density 'Kiwa' assemblages observed in close proximity to sources of vent fluids are constrained by the thermal limit of elevated temperatures and the availability of resources for chemosynthetic nutrition. Although adult Kiwaidae depend on epibiotic chemosynthetic bacteria for nutrition, females move offsite after extrusion of their eggs to protect brooding embryos from the chemically harsh, thermally fluctuating vent environment. Consequently, brooding females in the periphery of the vent field are in turn restricted by low-temperature physiological boundaries of the deep-water Southern Ocean environment. Females have a high reproductive investment in few, large, yolky eggs, facilitating full lecithotrophy, with the release of larvae prolonged, and asynchronous. After embryos are released, larvae are reliant on locating isolated active areas of hydrothermal flow in order to settle and survive as chemosynthetic adults. Where the cold water restricts the ability of all adult stages to migrate over long distances, these low temperatures may facilitate the larvae in the location of vent sites by extending the larval development period through hypometabolism. These differential life-history adaptations to contrasting thermal environments lead to a disjunct life history among males and females of K. tyleri, which is key to their success in the Southern Ocean vent environment. We highlight the complexity in understanding the importance of life-history biology, in combination with environmental, ecological and physiological factors contributing to the overall global distribution of vent-endemic species. PMID:25732205

  16. Deep-sea food web analysis using cross-reacting antisera

    NASA Astrophysics Data System (ADS)

    Feller, Robert J.; Zagursky, Gregory; Day, Elizabeth A.

    1985-04-01

    The high incidence of unrecognizable prey in the stomachs of deep-sea predators prompted the application of serological methods for identification of trophic connections. Antisera to whole-organism extracts of estuarine taxa cross-reacted with antigenic protein extracts of mid-water and deep-sea taxa along phylogenetically correct lines, indicating their potential as tools for gut contents immunoassay. Stomach, intestine, and rectum contents of grenadiers ( Coryphaenoides armatus) trapped at 2500 m in the North Atlantic were analyzed visually and with 32 antisera representing taxa from 10 common deep-sea phyla. While visual analysis only revealed the presence of fluids, parasites, crustacean exoskeletons, and gastropod opercula, the immunoassay indicated the presence of antigenic proteins from holothurian, anemone, gastropod, decapod, and foraminiferan prey in the same samples. This qualitative serological identification of prey at non-specific taxonomic levels provides evidence that benthic predation may be important within deep-sea communities. The immunoassay technique, although not a panacea for elucidating food web dynamics in remote environments, may be useful when other methods fail to identify trophic pathways.

  17. [Feeding changes for three Sphoeroides species (Tetraodontiformes: Tetraodontidae) after Isidore hurricane impact in Carbonera Inlet, Southeastern Gulf of Mexico].

    PubMed

    Palacios-Sánchez, Sonia Eugenia; Vega-Cendejas, María Eugenia

    2010-12-01

    The coexistence of ecologically similar species may occur because of resources distribution, such as prey and habitat type and segregation time, that minimizes the interspecific competition. The changes brought about by Hurricane Isidore in the distribution of food resources by three coexisting fish species of the family Tetraodontidae (Sphoeroides nephelus, S. spengleri and S testudineus), were analyzed at the Carbonera Inlet. Sphoeroides spp. based their food on benthic organisms; principally, they consume mussels (Brachidontes sp.), barnacles (Balanus sp.) and gastropods (Crepidula sp). Before hurricane impact, the three species share the available food resources in different proportions (bivalves, gastropods, barnacles and decapods), according to different strategies that enabled them to coexist and reduce interspecific competition. After the impact, the abundance of available prey decreased and the interespecific competition for food increased, leading to S. testudines and S. nephelus change their trophic spectrum (xiphosurans, amphipods, isopods and detritus) and displacing S. splengleri of the inlet. The distribution of food resources was conditioned by the abundance and diversity of prey, as well as the adaptive response of each species. PMID:21250477

  18. Distribution patterns of macrobenthic fauna communities in Deukryang Bay, one of the environment conservation areas of Korea

    NASA Astrophysics Data System (ADS)

    Seo, Jin-Young; Lim, Hyun-Sig; Choi, Jin-Woo

    2014-06-01

    Macrobenthic fauna were collected seasonally at 44 sites in Deukryang Bay from February to November, 2012. The species number of macrobenthic fauna was in the range of 140 to 181, and polychaetes comprised 41.4% of them. The average density of the whole study area changed seasonally from 755 to 1,507 ind. m-2, and the most abundant fauna group was crustaceans which accounted for 55.1% of total abundance. An amphipod species Nippopisella nagatai was the most dominant species and a decapod species Xenophthalmus pinnotheroides, an amphipod species Photis longicaudata, and a polychaete species Paralacydonia paradoxa were also dominant in all seasons. The mean seasonal values of Shannon's diversity index (H') were in the range of 2.2-2.4, and those values for the evenness index and richness index were 0.7-0.7 and 4.6-5.7, respectively. From the cluster analysis, Deukryang Bay could be divided into 3 or 4 station groups with its specific fauna composition. The cluster analysis and an nMDS ordination revealed that local environmental factors such as water depth were related to the spatial delineation of macrobenthic fauna communities in Deukryang Bay.

  19. Reprint of “Deep epibenthic communities in two contrasting areas of the Balearic Islands (western Mediterranean)”

    NASA Astrophysics Data System (ADS)

    Ramón, Montserrat; Abelló, Pere; Ordines, Francesc; Massutí, Enric

    2014-10-01

    Epibenthic communities were studied in two areas, off western and southern Mallorca (Balearic Islands, western Mediterranean), which differ in the oceanographic conditions and show different degrees of oligotrophy. Sampling was performed with beam trawl at two seasons (December 2009 and July 2010) and at depths between 228 and 900 m. A total of 199 taxa were identified, of which the most diverse were decapod crustaceans and fishes. Depth was the main factor structuring megafaunal assemblages. In the shelf break the shrimps Plesionika heterocarpus, P. antigai, Processa nouveli and P. canaliculata were dominant. In the upper slope, P. acanthonotus, Boreomysis arctica, Gaidropsarus biscayensis and Aristeus antennatus were the species that most contributed to the group formation, whereas in the middle slope the crustaceans P. acanthonotus and Munida tenuimana dominated. Specific abundances were relatively low everywhere. Diversity H? values ranged from 2.19 to 3.17, being higher in Sóller. Using species abundance data, significant differences were identified concerning both area and season in both shelf break and upper slope strata, while no significant differences were found in the middle slope stratum. The analysis of functional groups showed that both depth and area had a significant effect on their differential distribution.

  20. High genetic diversity and absence of founder effects in a worldwide aquatic invader.

    PubMed

    Lejeusne, Christophe; Saunier, Alice; Petit, Nicolas; Béguer, Mélanie; Otani, Michio; Carlton, James T; Rico, Ciro; Green, Andy J

    2014-01-01

    The introduced oriental shrimp Palaemon macrodactylus has recently become widespread in temperate estuaries worldwide. However, this recent worldwide spread outside of its native range arises after a previous introduction to the US Pacific coast, where it was restricted for more than 30 years. Using a phylogeographic approach, the present work investigates the genetic history of the invasion of this decapod worldwide. Japan acted as the main native source area for worldwide introduced populations, but other native areas (likely South Korea and China) may act as source populations as well. The recently introduced European and NW Atlantic populations result from colonization from both Japan and an unknown area of the native range, although colonization from the NE Pacific could not be ruled out. Most introduced populations had higher haplotypic diversity than most native populations. P. macrodactylus has a strong potential to become one of the most widespread introduced species and may become the dominant estuarine shrimp in Europe. The ecological and economic consequences of this invasion remain to be thoroughly evaluated. PMID:25060780

  1. Emigration of penaeid shrimp from the once-through cooling lake of Cedar Bayou Steam Electric Generating Station, Baytown, Texas

    SciTech Connect

    Chen, Y.L.

    1983-01-01

    Migration and distribution of two decapod shrimp, Penaeus setiferus and P. aztecus, in the cooling-water system of a power plant on the Texas coast were investigated, with emphasis on the seaward emigration from the cooling lake. Samples were collected every two weeks for a year by straining water leaving the lake over a drop structure, trawling in the cooling lake, and flushed from the intake screen. Shrimp catches at the drop structure were positively correlated with the standing population in the cooling lake. Significantly more shrimp passed over the drop structure nocturnally than diurnally. Shrimp caught at the drop structure diurnally averaged either smaller or similar in size to the shrimp taken there at night. The passage of a cold front enhanced migration and initially increased and then reduced the mean size of shrimp passing the drop structure. Higher percentages of the shrimp population in the cooling lake emigrated near new moon than full moon. The moon-phase effects appeared to be due to the moon cycle itself rather than to the intinsity of moon light. Significantly more shrimp of both species emigrated during the hours of ebbing than incoming tide. As the lake surface was above high tide level, an endogenous timing mechanism rather than evironmental factors associated with tidal rhythms controlled this emigration pattern. A temperature drop of up to 0.23 C/hour significantly increased P. aztecus emigration.

  2. A New PCR-Based Method Shows That Blue Crabs (Callinectes sapidus (Rathbun)) Consume Winter Flounder (Pseudopleuronectes americanus (Walbaum))

    PubMed Central

    Collier, Jackie L.; Fitzgerald, Sean P.; Hice, Lyndie A.; Frisk, Michael G.; McElroy, Anne E.

    2014-01-01

    Winter flounder (Pseudopleuronectes americanus) once supported robust commercial and recreational fisheries in the New York (USA) region, but since the 1990s populations have been in decline. Available data show that settlement of young-of-the-year winter flounder has not declined as sharply as adult abundance, suggesting that juveniles are experiencing higher mortality following settlement. The recent increase of blue crab (Callinectes sapidus) abundance in the New York region raises the possibility that new sources of predation may be contributing to juvenile winter flounder mortality. To investigate this possibility we developed and validated a method to specifically detect winter flounder mitochondrial control region DNA sequences in the gut contents of blue crabs. A survey of 55 crabs collected from Shinnecock Bay (along the south shore of Long Island, New York) in July, August, and September of 2011 showed that 12 of 42 blue crabs (28.6%) from which PCR-amplifiable DNA was recovered had consumed winter flounder in the wild, empirically supporting the trophic link between these species that has been widely speculated to exist. This technique overcomes difficulties with visual identification of the often unrecognizable gut contents of decapod crustaceans, and modifications of this approach offer valuable tools to more broadly address their feeding habits on a wide variety of species. PMID:24454797

  3. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (Gulf of Mexico). Black drum. [Pogonias cromis

    SciTech Connect

    Sutter, F.C.; Waller, R.S.; McIlwain, T.D.

    1986-04-01

    Black drum are primarily an estuarine species. The time of black drum spawning depends on location. In Texas waters, heaviest spawning activity occurs during February and March near passes in open bays and estuaries, while in deeper Gulf waters they spawn from November to April. Larvae are transported into the estuarine environment where they grow to the juvenile stage, living in shallow, muddy waters, tolerating a wide range of environmental conditions. Black drum are commercially harvested by a variety of gears, with the majority of US landings taken in Gulf waters off Texas. They are also an important recreational species with more fish caught in the sport catch than harvested commercially. Young black drum feed on invertebrates and small fish, while adults consume mollusks and some decapods. Adults are found in salinities of 9 to 26 ppt and in water temperatures of 12 to 33/sup 0/C. Juveniles are taken over muddy bottoms and adults are usually found over sand or soft bottoms and over oyster reefs or clam shell.

  4. Fine-Scale Distribution and Spatial Variability of Benthic Invertebrate Larvae in an Open Coastal Embayment in Nova Scotia, Canada

    PubMed Central

    Daigle, Rémi M.; Metaxas, Anna; deYoung, Brad

    2014-01-01

    This study quantified the fine- scale (0.5 km) of variability in the horizontal distributions of benthic invertebrate larvae and related this variability to that in physical and biological variables, such as density, temperature, salinity, fluorescence and current velocity. Larvae were sampled in contiguous 500-m transects along two perpendicular 10-km transects with a 200-µm plankton ring net (0.75-m diameter) in St. George’s Bay, Nova Scotia, Canada, in Aug 2009. Temperature, conductivity, pressure and fluorescence were measured with a CTD cast at each station, and currents were measured with an Acoustic Doppler Current Profiler moored at the intersection of the 2 transects. Gastropod, bivalve and, to a lesser extent, bryozoan larvae had very similar spatial distributions, but the distribution of decapod larvae had a different pattern. These findings suggest that taxonomic groups with functionally similar larvae have similar dispersive properties such as distribution and spatial variability, while the opposite is true for groups with functionally dissimilar larvae. The spatial variability in larval distributions was anisotropic and matched the temporal/spatial variability in the current velocity. We postulate that in a system with no strong oceanographic features, the scale of spatially coherent physical forcing (e.g. tidal periodicity) can regulate the formation or maintenance of larval patches; however, swimming ability may modulate it. PMID:25153075

  5. Involvement of the antioxidant system in differential sensitivity of Carcinus maenas to fenitrothion exposure.

    PubMed

    Rodrigues, A P; Gravato, C; Guimarăes, L

    2013-10-01

    Carcinus maenas is an invertebrate with worldwide distribution and high ability to adapt to different environments, which is frequently used in environmental monitoring. Despite this, it is not clear how historical exposure to moderate contamination may influence sensitivity to further chemical stress in this important decapod species. This study investigated differential responses to organophosphate fenitrothion of C. maenas from a moderately contaminated estuary and a low impacted one, using in vitro and in vivo biomarker assays. To clarify potential differences in sensitivity, a biochemical characterisation of muscle cholinesterases was first performed. The results indicated acetylcholinesterase (AChE) as the main form present in C. maenas muscle. Exposure assays revealed that crabs from the moderately contaminated site were less sensitive to fenitrothion showing lower AChE inhibition than those from the low impacted site. Other biomarker changes detected in these animals were: increased anaerobic metabolism (muscle lactate dehydrogenase), enhanced phase II biotransformation (glutathione S-transferases in the digestive gland) and antioxidant defences (i.e., activities of glutathione reductase, glutathione peroxidase and catalase, and levels of total glutathiones in the digestive gland). Altogether, the results pointed out a role for the glutathione redox system towards tolerance to fenitrothion exposure. PMID:24056931

  6. Daily variations of the antioxidant defense system of the lithodid crab Lithodes santolla.

    PubMed

    Schvezov, Natasha; Lovrich, Gustavo A; Tapella, Federico; Romero, M Carolina

    2013-04-01

    Several physiological processes can induce daily variations in aerobic metabolism. Lithodes santolla is a decapod crustacean of special concern since it is a sub-Antarctic species of commercial interest. The aim of this work was to study in L. santolla the daily variations in levels of enzymatic and non-enzymatic antioxidants, lipid peroxidation and protein oxidation, and haemolymphatic pH. Males of L. santolla of commercial size were randomly dissected every 4 h during a period of 24 h. Enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase and glutathione peroxidase were determined in samples of gills, muscle, hepatopancreas and haemolymph. Ascorbic acid, total glutathione, lipid peroxidation and protein oxidation were also determined in all tissues. Gills showed the highest enzymatic activity and hepatopancreas the highest concentration of non-enzymatic antioxidants. Maximum antioxidant activity was during the dark phase in gills and during the photophase in the haemolymph. Muscle showed significant daily variations, with peaks during the photophase and scotophase. Overall, an antioxidant protective mechanism is present in all tissues, where SOD and CAT represent the first line of defense. The defense mechanism in L. santolla seems to be more active during the dark phase, with slight differences among the analyzed tissues, indicating a higher metabolic rate. PMID:23376123

  7. Ecological effects of ocean acidification and habitat complexity on reef-associated macroinvertebrate communities

    PubMed Central

    Fabricius, K. E.; De'ath, G.; Noonan, S.; Uthicke, S.

    2014-01-01

    The ecological effects of ocean acidification (OA) from rising atmospheric carbon dioxide (CO2) on benthic marine communities are largely unknown. We investigated in situ the consequences of long-term exposure to high CO2 on coral-reef-associated macroinvertebrate communities around three shallow volcanic CO2 seeps in Papua New Guinea. The densities of many groups and the number of taxa (classes and phyla) of macroinvertebrates were significantly reduced at elevated CO2 (425–1100 µatm) compared with control sites. However, sensitivities of some groups, including decapod crustaceans, ascidians and several echinoderms, contrasted with predictions of their physiological CO2 tolerances derived from laboratory experiments. High CO2 reduced the availability of structurally complex corals that are essential refugia for many reef-associated macroinvertebrates. This loss of habitat complexity was also associated with losses in many macroinvertebrate groups, especially predation-prone mobile taxa, including crustaceans and crinoids. The transition from living to dead coral as substratum and habitat further altered macroinvertebrate communities, with far more taxa losing than gaining in numbers. Our study shows that indirect ecological effects of OA (reduced habitat complexity) will complement its direct physiological effects and together with the loss of coral cover through climate change will severely affect macroinvertebrate communities in coral reefs. PMID:24307670

  8. Trophic amplification of climate warming

    PubMed Central

    Kirby, Richard R.; Beaugrand, Gregory

    2009-01-01

    Ecosystems can alternate suddenly between contrasting persistent states due to internal processes or external drivers. It is important to understand the mechanisms by which these shifts occur, especially in exploited ecosystems. There have been several abrupt marine ecosystem shifts attributed either to fishing, recent climate change or a combination of these two drivers. We show that temperature has been an important driver of the trophodynamics of the North Sea, a heavily fished marine ecosystem, for nearly 50 years and that a recent pronounced change in temperature established a new ecosystem dynamic regime through a series of internal mechanisms. Using an end-to-end ecosystem approach that included primary producers, primary, secondary and tertiary consumers, and detritivores, we found that temperature modified the relationships among species through nonlinearities in the ecosystem involving ecological thresholds and trophic amplifications. Trophic amplification provides an alternative mechanism to positive feedback to drive an ecosystem towards a new dynamic regime, which in this case favours jellyfish in the plankton and decapods and detritivores in the benthos. Although overfishing is often held responsible for marine ecosystem degeneration, temperature can clearly bring about similar effects. Our results are relevant to ecosystem-based fisheries management (EBFM), seen as the way forward to manage exploited marine ecosystems. PMID:19740882

  9. Comparison of the feeding apparatus and diet of European sardines Sardina pilchardus of Atlantic and Mediterranean waters: ecological implications.

    PubMed

    Costalago, D; Garrido, S; Palomera, I

    2015-04-01

    In this study, the feeding apparatus (gill rakers, GR) and the diet composition of European sardine Sardina pilchardus populations living in two contrasting environments were compared: the upwelling area off western Iberia and the comparatively less productive region of the north-western Mediterranean Sea. The importance of local adaptations in the trophic ecology of this species was estimated. Sardina pilchardus from the Atlantic Iberian coast and from the north-western Mediterranean Sea have clear differences in the feeding apparatus and diet compositions. Those from the Atlantic Iberian coast have significantly more GRs than S. pilchardus of the same size range in the Mediterranean Sea. While S. pilchardus from the Mediterranean Sea mostly depend on prey ranging between 750-1500 and 3000-4000?µm, corresponding mostly to cladocerans, decapods and copepods, those from the Atlantic depend on smaller prey (50-500 and 1000-1500?µm) that include phytoplankton and copepods, particularly during summer months, and S. pilchardus eggs during the winter. The marked difference between the trophic ecology of S. pilchardus in the two areas studied appears to have originated from different dietary strategies that the two populations have adopted in contrasting feeding environments. These differences are shown to profoundly affect the size and quality of prey consumed, and the effect of cannibalism on the populations. PMID:25846858

  10. The Role of Road Corridors on Riparian Vegetation and Stream Ecosystem Dynamics.

    NASA Astrophysics Data System (ADS)

    Crowl, T.; Heartsill-Scalley, T.; Covich, A. P.; Hein, C. L.

    2005-05-01

    Stream ecosystems are dependent on organic material from the riparian zone as a major energy source for the food web. Leaf litter (organic matter) entering streams is processed by a combination of physical and biological mechanisms. In temperate streams, microbial conditioning is important for detrital processing. Much less is known in tropical systems, especially those dominated by large macro-consumers such as decapods. There is also variation among species in terms of processing rates that are explained by nutritional value, chemical defenses and palatability. These traits are a function of plant life history. If riparian species are being significantly altered through invasions by exotic species along road corridors, then we can expect changes in detrital processing rates and ultimately, ecosystem function. As part of a biocomplexity project in Puerto Rico, we are quantifying the changes to species composition and trait-mediated decomposition and foodweb dynamics. Where roads are constructed, exotic invasives include Spathodea, Bambusa, Syzigium and a various grasses. Because of the chemical defenses and their high nutritional value, decomposition rates on these species is much higher than for native riparian species. The increased breakdown rates may `accelerate' ecosystem processes and either enhance or destabilize existing food web linkages.

  11. Some like it hot: Thermal tolerance and oxygen supply capacity in two eurythermal crustaceans.

    PubMed

    Ern, Rasmus; Huong, Do Thi Thanh; Phuong, Nguyen Thanh; Madsen, Peter Teglberg; Wang, Tobias; Bayley, Mark

    2015-01-01

    Thermal sensitivity of the cardiorespiratory oxygen supply capacity has been proposed as the cardinal link underlying the upper boundary of the temperature niche in aquatic ectotherms. Here we examined the evidence for this link in two eurythermal decapods, the Giant tiger shrimp (Penaeus monodon) and the European crayfish (Astacus astacus). We found that both species have a temperature resistant cardiorespiratory system, capable of maintaining oxygen delivery up to their upper critical temperature (Tcrit). In neither species was Tcrit reduced in hypoxia (60% air saturation) and both species showed an exponential increase in heart and gill ventilation rates up to their Tcrit. Further, failure of action potential conduction in preparations of A. astacus motor neurons coincided with Tcrit, indicating that compromised nervous function may provide the underlying determinant for Tcrit rather than oxygen delivery. At high temperatures, absolute aerobic scope was maintained in P. monodon, but reduced in A. astacus. However, A. astacus also displayed reduced exercise intensity indicating that impaired muscle performance with resulting reduced tissue oxygen demand may explain the reduced scope rather than insufficient oxygen supply capacity. This interpretation agrees with early literature on aquatic ectotherms, correlating loss of nervous function with impaired locomotion as temperatures approach Tcrit. PMID:26030412

  12. Brachyuran and anomuran crabs associated with Schizoporella unicornis (Ectoprocta, Cheilostomata) from southeastern Brazil.

    PubMed

    Alves, Douglas F R; Barros-Alves, Samara P; Lima, Daniel J M; Cobo, Valter J; Negreiros-Fransozo, Maria Lucia

    2013-03-01

    The main goals of this investigation were to describe the community structure of anomuran and brachyuran crabs inhabiting reefs constituted by colonies of Schizoporella unicornis, and to provide a species importance ranking for this community. Collections were carried out on S. unicornis reefs at two-month intervals from May 2003 to May 2004, in the rocky sublittoral of the southeastern Brazilian coast. Relative abundance and occurrence were used to rank these species in the hierarchy importance. A total of 2,018 individuals were obtained, in 11 families, 22 genera and 31 species. Porcellanidae and Pilumnidae were the most abundant families, comprising respectively almost 60% and 15% of individuals sampled. The species ranking indicated four main groups A, B, C and D, with group A subdivided. Subgroup A1 contained 9 species, including the species of greatest ecological importance for community regarding abundance and occurrence. The great abundance of crabs associated with S. unicornis seems to be the result of its recognized importance during the crab developmental cycle, and as shelter and food for some Decapod species. These observations reveal the importance of conserving the areas occupied by these reef colonies, which appear to be an important environment for maintaining local biodiversity. PMID:23538959

  13. How multiple conductances determine electrophysiological properties in a multicompartment model.

    PubMed

    Taylor, Adam L; Goaillard, Jean-Marc; Marder, Eve

    2009-04-29

    Most neurons have large numbers of voltage- and time-dependent currents that contribute to their electrical firing patterns. Because these currents are nonlinear, it can be difficult to determine the role each current plays in determining how a neuron fires. The lateral pyloric (LP) neuron of the stomatogastric ganglion of decapod crustaceans has been studied extensively biophysically. We constructed approximately 600,000 versions of a four-compartment model of the LP neuron and distributed 11 different currents into the compartments. From these, we selected approximately 1300 models that match well the electrophysiological properties of the biological neuron. Interestingly, correlations that were seen in the expression of channel mRNA in biological studies were not found across the approximately 1300 admissible LP neuron models, suggesting that the electrical phenotype does not require these correlations. We used cubic fits of the function from maximal conductances to a series of electrophysiological properties to ask which conductances predominantly influence input conductance, resting membrane potential, resting spike rate, phasing of activity in response to rhythmic inhibition, and several other properties. In all cases, multiple conductances contribute to the measured property, and the combinations of currents that strongly influence each property differ. These methods can be used to understand how multiple currents in any candidate neuron interact to determine the cell's electrophysiological behavior. PMID:19403824

  14. The Elusive Baseline of Marine Disease: Are Diseases in Ocean Ecosystems Increasing?

    PubMed Central

    2004-01-01

    Disease outbreaks alter the structure and function of marine ecosystems, directly affecting vertebrates (mammals, turtles, fish), invertebrates (corals, crustaceans, echinoderms), and plants (seagrasses). Previous studies suggest a recent increase in marine disease. However, lack of baseline data in most communities prevents a direct test of this hypothesis. We developed a proxy to evaluate a prediction of the increasing disease hypothesis: the proportion of scientific publications reporting disease increased in recent decades. This represents, to our knowledge, the first quantitative use of normalized trends in the literature to investigate an ecological hypothesis. We searched a literature database for reports of parasites and disease (hereafter “disease”) in nine marine taxonomic groups from 1970 to 2001. Reports, normalized for research effort, increased in turtles, corals, mammals, urchins, and molluscs. No significant trends were detected for seagrasses, decapods, or sharks/rays (though disease occurred in these groups). Counter to the prediction, disease reports decreased in fishes. Formulating effective resource management policy requires understanding the basis and timing of marine disease events. Why disease outbreaks increased in some groups but not in others should be a priority for future investigation. The increase in several groups lends urgency to understanding disease dynamics, particularly since few viable options currently exist to mitigate disease in the oceans. PMID:15094816

  15. Long-term eruptive activity at a submarine arc volcano

    USGS Publications Warehouse

    Embley, R.W.; Chadwick, W.W., Jr.; Baker, E.T.; Butterfield, D.A.; Resing, J.A.; De Ronde, C. E. J.; Tunnicliffe, V.; Lupton, J.E.; Juniper, S.K.; Rubin, K.H.; Stern, R.J.; Lebon, G.T.; Nakamura, K.-I.; Merle, S.G.; Hein, J.R.; Wiens, D.A.; Tamura, Y.

    2006-01-01

    Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes. ?? 2006 Nature Publishing Group.

  16. Deep epibenthic communities in two contrasting areas of the Balearic Islands (western Mediterranean)

    NASA Astrophysics Data System (ADS)

    Ramón, Montserrat; Abelló, Pere; Ordines, Francesc; Massutí, Enric

    2014-04-01

    Epibenthic communities were studied in two areas, off western and southern Mallorca (Balearic Islands, western Mediterranean), which differ in the oceanographic conditions and show different degrees of oligotrophy. Sampling was performed with beam trawl at two seasons (December 2009 and July 2010) and at depths between 228 and 900 m. A total of 199 taxa were identified, of which the most diverse were decapod crustaceans and fishes. Depth was the main factor structuring megafaunal assemblages. In the shelf break the shrimps Plesionika heterocarpus, P. antigai, Processa nouveli and P. canaliculata were dominant. In the upper slope, P. acanthonotus, Boreomysis arctica, Gaidropsarus biscayensis and Aristeus antennatus were the species that most contributed to the group formation, whereas in the middle slope the crustaceans P. acanthonotus and Munida tenuimana dominated. Specific abundances were relatively low everywhere. Diversity H? values ranged from 2.19 to 3.17, being higher in Sóller. Using species abundance data, significant differences were identified concerning both area and season in both shelf break and upper slope strata, while no significant differences were found in the middle slope stratum. The analysis of functional groups showed that both depth and area had a significant effect on their differential distribution.

  17. Tyrosine hydroxylase protein expression in ventral nerve cord of Neotropical freshwater crab.

    PubMed

    Ponzoni, Silvia

    2014-12-01

    Given the importance of catecholamines in coordinating physiological and behavioral responses in brachyurans, the present study was designed to investigate the distribution of tyrosine hydroxylase (TH)-positive cells and fibers in the ventral nerve cord of Dilocarcinus pagei the Neotropical freshwater crab. TH immunoreactivity was visualized in adult crabs of both sexes, during the intermolt period. We found TH-positive cells that have not been previously described in brachyurans. Specifically, we found a pair of TH-positive cells in the ventral region of the thoracic ganglion, and in ventral and dorsal regions of the abdominal (pleonic) ganglion, suggesting catecholaminergic modulation of claws' function and abdominal structures. In addition, great population of TH-positive cells was observed in the subesophageal ganglion, indicating conservation during evolution of catecholamines in this ganglion of decapods. Dopamine is present in cells and fiber tracts of brachyuran ventral nerve cord, projecting to endocrine, cardiac and digestive structures, suggesting widespread modulation and control of physiological functions and behavior. Dopamine plays a central role in movement and psychiatric disorders in humans. Information on dopaminergic function in the nervous system of invertebrates should improve the understanding of its function in more complex systems, such as human beings. PMID:25217291

  18. Polychlorinated biphenyl contamination of the spider crab (Maja brachydactyla): influence of physiological and ecological processes.

    PubMed

    Bodin, Nathalie; Caisey, Xavier; Abarnou, Alain; Loizeau, Véronique; Latrouite, Daniel; Le Guellec, Anne-Marie; Guillou, Monique

    2007-03-01

    Maja brachydactyla is a decapod crustacean widely distributed along the Northeast Atlantic coasts. The main objective of this work was to establish the influence of ontogenic factors, such as growth, aging, seasonal migrations, and reproduction, on the contamination of this species by polychlorinated biphenyls (PCBs). Two populations were studied: One in the Seine Bay (Eastern English Channel), which is exposed to greatly contaminated discharges from the Seine River, and one in the Iroise Sea (Western Brittany), which is little contaminated by such man-made compounds. At both sampling areas, PCB analysis revealed concentrations in hepatopancreas that were 10- and 50-fold higher than concentrations in gonads and muscle, respectively. Levels of 2,2',4,4',5,5'-hexachlorobiphenyl (CB153) increased with the age of the spider crabs, whereas their seasonal migrations had no direct effect. No significant sex effect was observed with regards to CB153 levels, but adult females exhibited PCB fingerprints different from those of males, probably because of the influence of the reproductive cycle on enzymatic system activity. Finally, spawning gave rise to a higher CB153 decontamination of female body burdens for specimens from the Iroise Sea than for those from the Seine Bay. PMID:17373508

  19. A developmental study of serotonin-immunoreactive neurons in the larval central nervous system of the spider crab Hyas araneus (Decapoda, Brachyura).

    PubMed

    Harzsch, S; Dawirs, R R

    1995-01-01

    Larval development in crabs is characterized by a striking double metamorphosis in the course of which the animals change from a pelagic to a benthic life style. The larval central nervous system has to provide an adequate behavioural repertoire during this transition. Thus, processes of neuronal reorganization and refinement of the early larval nervous system could be expected to occur in the metamorphosing animal. In order to follow identified sets of neurons throughout metamorphosis, whole mount preparations of the brain and ventral nerve cord of laboratory reared spider crab larvae (Hyas araneus) were labelled with an antibody against the neurotransmitter serotonin. The system of serotonin-immunoreactive cell bodies, fibres and neuropils is well-developed in newly hatched larvae. Most immunoreactive structures are located in the protocerebrum, with fewer in the suboesophaegeal ganglia, while the thoracic and abdominal ganglia initially comprise only a small number of serotonergic neurons and fibres. However, there are significant alterations in the staining pattern through larval development, some of which are correlated to metamorphic events. Accordingly, new serotonin-immunoreactive cells are added to the early larval set and the system of immunoreactive fibres is refined. These results are compared to the serotonergic innervation in other decapod crustaceans. PMID:9372132

  20. SPERMIOGENESIS IN THE CRAYFISH (PROCAMBARUS CLARKII)

    PubMed Central

    Moses, Montrose J.

    1961-01-01

    The sperm of the crayfish, Procambarus clarkii, is relatively simple among decapod sperm and was described in the first paper of this series (28). The present paper details the development of this sperm as followed with the light and electron microscopes. The process is divided into six stages for purposes of description. The main points of interest discussed are the absence of mitochondria or mitochondrial derivatives in the mature sperm, the development of a complex acrosome in the absence of highly organized characteristic Golgi apparatus but in the presence of small stacks of annulate lamellae, and the changes in the nucleus. Of the latter, the elaborate convoluted sheets of membrane that are extensions of the nuclear envelope are unique. The nucleus undergoes unusual changes in size and shape that are accompanied by several phases of organization of the chromatin. In the mature sperm the nucleus is empty-appearing and notably lacking in any apparent high degree of order. The entire development of the sperm is consonant with the idea that the fate of the mitochondria and centrioles, structures that figure prominently in the elaborate architecture of flagellate sperm, is associated with the lack of a flagellum. PMID:13773055

  1. Expression of Na(+)/K(+)-ATPase alpha-subunit mRNA during embryonic development of the crayfish Astacus leptodactylus.

    PubMed

    Serrano, L; Towle, D W; Charmantier, G; Spanings-Pierrot, C

    2007-06-01

    Astacus leptodactylus is a decapod crustacean fully adapted to freshwater where it spends its entire life cycle after hatching under huge osmoconcentration differences between the hemolymph and surrounding freshwater. We investigated the expression of mRNA encoding one ion transport-related protein, Na(+)/K(+)-ATPase alpha-subunit, and one putative housekeeping gene, beta-actin, during crayfish ontogenesis using quantitative real-time PCR. A 216-amino acid part of the open reading frame region of the cDNA coding for the Na(+)/K(+)-ATPase alpha-subunit was sequenced from total embryo, juvenile and adult gill tissues. The predicted amino acid sequence showed a high percentage similarity to those of other invertebrates (up to 95%) and vertebrates (up to 69%). beta-actin expression exhibited modest changes through embryonic development and early post-embryonic stage. The Na(+)/K(+)-ATPase alpha-subunit gene was expressed in all studied stages from metanauplius to juvenile. Two peaks of expression were observed: one in young embryos at 25% of embryonic development (EI=100 mum), and one in embryos just before hatching (at EI=420 mum), continuing in the freshly hatched juveniles. The Na(+)/K(+)-ATPase expression profile during embryonic development is time-correlated with the occurrence of other features, including ontogenesis of excretory antennal glands and differentiation of gill ionocytes linked to hyperosmoregulation processes and therefore involved in freshwater adaptation. PMID:20483286

  2. Functional aspects of cHH C-terminal amidation in crayfish species.

    PubMed

    Mosco, Alessandro; Edomi, Paolo; Guarnaccia, Corrado; Lorenzon, Simonetta; Pongor, Sándor; Ferrero, Enrico A; Giulianini, Piero G

    2008-04-10

    The crustacean hyperglycemic hormone is the most abundant neuropeptide present in the eyestalk of Crustacea and its main role is to control the glucose level in the hemolymph. Our study was aimed at assessing the importance of C-terminal amidation for its biological activity. Two recombinant peptides were produced, Asl-rcHH-Gly with a free carboxyl terminus and Asl-rcHH-amide with an amidated C-terminus. Homologous bioassays performed on the astacid crayfish Astacus leptodactylus showed that the amidated peptide had a stronger hyperglycemic effect compared to the non-amidated peptide. To assess the relevance of amidation also in other decapods and how much the differences in the cHH amino acid sequence can affect the functionality of the peptides, we carried out heterologous bioassays on the cambarid Procambarus clarkii and palaemonid Palaemon elegans. The Asl-rcHH-amide elicited a good response in P. clarkii and in P. elegans. The injection of Asl-rcHH-Gly evoked a weak response in both species. These results prove the importance of C-terminal amidation for the biological activity of cHH in crayfish as well as the role of the peptide primary sequence for the species-specificity hormone-receptor recognition. PMID:18281112

  3. Species-specific effects on hemolymph glucose control by serotonin, dopamine, and L-enkephalin and their inhibitors in Squilla mantis and Astacus leptodactylus (crustacea).

    PubMed

    Lorenzon, Simonetta; Brezovec, Sara; Ferrero, Enrico A

    2004-09-01

    Hemolymph glucose level is controlled by crustacean Hyperglycemic Hormone (cHH) released from the eyestalk neuroendocrine centers under conditions of both physiological and environmental stress. Biogenic amines and enkephalin have been found to mediate the release of several neurohormones from crustacean neuroendocrine tissue. We investigated the effect of serotonin, dopamine, and Leucine-enkephalin in vivo--injected into the stomatopod Squilla mantis and the decapod Astacus leptodactylus--whether increasing or depressing glycemia. Serotonin had a marked effect in elevating glucose level compared with initial values in both species. 5-HT1-like receptors are more involved in mediating serotonin action as co-injected cyproheptadine was a more effective antagonist than ketanserin (5-HT2-like receptor inhibitor). Dopamine injection in intact animals produced a decrease below initial levels of hemolymph glucose. This effect was significantly antagonized by domperidone. No significant effect of both amines occurred in eyestalkless animals. L-enkephalin shows a differential effect: in S. mantis it induced hypoglycemia while in A. leptodactylus it caused an increase of glucose level. Co-injected antagonist naloxone affected the direction of the response. Serotonin appears to provide a major control on glucose mobilization, whereas dopamine and L-enkephalin act as modulators whose plasticity in use or action varies among species. PMID:15559934

  4. Biomimicking micropatterned surfaces and their effect on marine biofouling.

    PubMed

    Brzozowska, Agata M; Parra-Velandia, Fernando J; Quintana, Robert; Xiaoying, Zhu; Lee, Serina S C; Chin-Sing, Lim; Ja?czewski, Dominik; Teo, Serena L-M; Vancso, Julius G

    2014-08-01

    When synthetic materials are submerged in marine environments, dissolved matter and marine organisms attach to their surfaces by a process known as marine fouling. This phenomenon may lead to diminished material performance with detrimental consequences. Bioinspired surface patterning and chemical surface modifications present promising approaches to the design of novel functional surfaces that can prevent biofouling phenomena. In this study, we report the synergistic effects of surface patterns, inspired by the marine decapod crab Myomenippe hardwickii in combination with chemical surface modifications toward suppressing marine fouling. M. hardwickii is known to maintain a relatively clean carapace although the species occurs in biofouling communities of tropical shallow subtidal coastal waters. Following the surface analysis of selected specimens, we designed hierarchical surface microtopographies that replicate the critical features observed on the crustacean surface. The micropatterned surfaces were modified with zwitterionic polymer brushes or with layer-by-layer deposited polyelectrolyte multilayers to enhance their antifouling and/or fouling-release potential. Chemically modified and unmodified micropatterned surfaces were subjected to extensive fouling tests, including laboratory assays against barnacle settlement and algae adhesion, and field static immersion tests. The results show a statistically significant reduction in settlement on the micropatterned surfaces as well as a synergistic effect when the microtopographies are combined with grafted polymer chains. PMID:25017490

  5. Testing the effect of habitat structure and complexity on nekton assemblages using experimental oyster reefs

    USGS Publications Warehouse

    Humphries, Austin T.; LaPeyre, Megan K.; Kimball, Matthew E.; Rozas, Lawrence P.

    2011-01-01

    Structurally complex habitats are often associated with more diverse and abundant species assemblages in both aquatic and terrestrial ecosystems. Biogenic reefs formed by the eastern oyster (Crassostrea virginica) are complex in nature and are recognized for their potential habitat value in estuarine systems along the US Atlantic and Gulf of Mexico coasts. Few studies, however, have examined the response of nekton to structural complexity within oyster reefs. We used a quantitative sampling technique to examine how the presence and complexity of experimental oyster reefs influence the abundance, biomass, and distribution of nekton by sampling reefs 4 months and 16 months post-construction. Experimental oyster reefs were colonized immediately by resident fishes and decapod crustaceans, and reefs supported a distinct nekton assemblage compared to mud-bottom habitat. Neither increased reef complexity, nor age of the experimental reef resulted in further changes in nekton assemblages or increases in nekton abundance or diversity. The presence of oyster reefs per se was the most important factor determining nekton usage.

  6. Taxonomic review of the orders Mysida and Stygiomysida (crustacea, peracarida).

    PubMed

    Meland, Kenneth; Mees, Jan; Porter, Megan; Wittmann, Karl J

    2015-01-01

    The order Mysida (2 families, 178 genera, 1132 species) contains species across a broad range of habitats, such as subterranean, fresh, brackish, coastal, and surface to deep-sea habitats. The Stygiomysida (2 families, 2 genera, 16 species), however, are found primarily in subterranean waters, but always in waters with a marine influence. The Mysida and Stygiomysida body is divided into three main regions: cephalon, thorax, and abdomen. They are shrimp-like in appearance, containing morphological features earlier referred to as defining a "caridoid facies". The shrimp-like morphology was to some extent diagnostic for the historic Decapod taxon Schizopoda, containing the Nebalia, Mysida, Lophogastrida, and Euphausiacea. In 1904 the concept of Schizopoda was abandoned, and the Mysidacea (Mysida and Lophogastrida) along with Cumacea, Amphipoda, Isopoda, and Tanaidacea were placed in a new taxon, the Peracarida. Later discoveries of groundwater mysids led to the establishment of Stygiomysida, but placement to either Lophogastrida or Mysida remained unclear. The presence of oostegites and absence of podobranchiae, coupled with non-statocyst bearing uropods have been used to classify the Stygiomysida as a primitive Mysida family, comparable to Petalophthalmidae. On the other hand, equally suggestive characters, but for a Lophogastrida affiliation, was suggested for the archaic foregut characters and again, non-statocyst bearing uropods. With the inclusion of DNA sequence data of ribosomal genes, sister group relationships between Stygiomysida, Lophogastrida, and Mictacea within the Peracarida are observed, which supports a classification of the Stygiomysida as a separate order removed from the Mysida. PMID:25927358

  7. Comparative Ultrastructure and Carbohydrate Composition of Gastroliths from Astacidae, Cambaridae and Parastacidae Freshwater Crayfish (Crustacea, Decapoda)

    PubMed Central

    Luquet, Gilles; Fernández, María S.; Badou, Aďcha; Guichard, Nathalie; Roy, Nathalie Le; Corneillat, Marion; Alcaraz, Gérard; Arias, José L.

    2012-01-01

    Crustaceans have to cyclically replace their rigid exoskeleton in order to grow.Most of them harden this skeleton by a calcification process. Some decapods (land crabs, lobsters and crayfish) elaborate calcium storage structures as a reservoir of calcium ions in their stomach wall, as so-called gastroliths. For a better understanding of the cyclic elaboration of these calcium deposits, we studied the ultrastructure of gastroliths from freshwater crayfish by using a combination of microscopic and physical techniques. Because sugars are also molecules putatively involved in the elaboration process of these biomineralizations, we also determined their carbohydrate composition. This study was performed in a comparative perspective on crayfish species belonging to the infra-order Astacidea (Decapoda, Malacostraca): three species from the Astacoidea superfamily and one species from the Parastacoidea superfamily. We observed that all the gastroliths exhibit a similar dense network of protein-chitin fibers, from macro- to nanoscale, within which calcium is precipitated as amorphous calcium carbonate. Nevertheless, they are not very similar at the molecular level, notably as regards their carbohydrate composition. Besides glucosamine, the basic carbohydrate component of chitin, we evidenced the presence of other sugars, some of which are species-specific like rhamnose and galacturonic acid whereas xylose and mannose could be linked to proteoglycan components. PMID:24970155

  8. Analysis of Stomach and Gut Microbiomes of the Eastern Oyster (Crassostrea virginica) from Coastal Louisiana, USA

    PubMed Central

    King, Gary M.; Judd, Craig; Kuske, Cheryl R.; Smith, Conor

    2012-01-01

    We used high throughput pyrosequencing to characterize stomach and gut content microbiomes of Crassostrea virginica, the Easter oyster, obtained from two sites, one in Barataria Bay (Hackberry Bay) and the other in Terrebonne Bay (Lake Caillou), Louisiana, USA. Stomach microbiomes in oysters from Hackberry Bay were overwhelmingly dominated by Mollicutes most closely related to Mycoplasma; a more rich community dominated by Planctomyctes occurred in Lake Caillou oyster stomachs. Gut communities for oysters from both sites differed from stomach communities, and harbored a relatively diverse assemblage of phylotypes. Phylotypes most closely related to Shewanella and a Chloroflexi strain dominated the Lake Caillou and Hackberry Bay gut microbiota, respectively. While many members of the stomach and gut microbiomes appeared to be transients or opportunists, a putative core microbiome was identified based on phylotypes that occurred in all stomach or gut samples only. The putative core stomach microbiome comprised 5 OTUs in 3 phyla, while the putative core gut microbiome contained 44 OTUs in 12 phyla. These results collectively revealed novel microbial communities within the oyster digestive system, the functions of the oyster microbiome are largely unknown. A comparison of microbiomes from Louisiana oysters with bacterial communities reported for other marine invertebrates and fish indicated that molluscan microbiomes were more similar to each other than to microbiomes of polychaetes, decapods and fish. PMID:23251548

  9. Cells from the immune system generate adult-born neurons in crayfish.

    PubMed

    Benton, Jeanne L; Kery, Rachel; Li, Jingjing; Noonin, Chadanat; Söderhäll, Irene; Beltz, Barbara S

    2014-08-11

    Neurogenesis is an ongoing process in the brains of adult decapod crustaceans. However, the first-generation precursors that produce adult-born neurons, which reside in a neurogenic niche, are not self-renewing in crayfish and must be replenished. The source of these neuronal precursors is unknown. Here, we report that adult-born neurons in crayfish can be derived from hemocytes. Following adoptive transfer of 5-ethynyl-2'-deoxyuridine (EdU)-labeled hemocytes, labeled cells populate the neurogenic niche containing the first-generation neuronal precursors. Seven weeks after adoptive transfer, EdU-labeled cells are located in brain clusters 9 and 10 (where adult-born neurons differentiate) and express appropriate neurotransmitters. Moreover, the number of cells composing the neurogenic niche in crayfish is tightly correlated with total hemocyte counts (THCs) and can be manipulated by raising or lowering THC. These studies identify hemocytes as a source of adult-born neurons in crayfish and demonstrate that the immune system is a key contributor to adult neurogenesis. PMID:25117683

  10. The complete mitochondrial genome of the mantid shrimp Oratosquilla oratoria (Crustacea: Malacostraca: Stomatopoda): Novel non-coding regions features and phylogenetic implications of the Stomatopoda.

    PubMed

    Liu, Yuan; Cui, Zhaoxia

    2010-09-01

    The complete mitochondrial (mt) genome sequence of Oratosquilla oratoria (Crustacea: Malacostraca: Stomatopoda) was determined; a circular molecule of 15,783 bp in length. The gene content and arrangement are consistent with the pancrustacean ground pattern. The mt control region of O. oratoria is characterized by no GA-block near the 3' end and different position of [TA(A)]n-blocks compared with other reported Stomatopoda species. The sequence of the second hairpin structure is relative conserved which suggests this region may be a synapomorphic character for the Stomatopoda. In addition, a relative large intergenic spacer (101 bp) with higher A+T content than that in control region was identified between the tRNA(Glu) and tRNA(Phe) genes. Phylogenetic analyses based on the current dataset of complete mt genomes strongly support the Stomatopoda is closely related to Euphausiacea. They in turn cluster with Penaeoidea and Caridea clades while other decapods form a separate group, which rejects the monophyly of Decapoda. This challenges the suitability of Stomatopoda as an outgroup of Decapoda in phylogenetic analyses. The basal position of Stomatopoda within Eumalacostraca according to the morphological characters is also questioned. PMID:20510661

  11. The complete mitochondrial genome of the mantid shrimp Harpiosquilla harpax, and a phylogenetic investigation of the Decapoda using mitochondrial sequences.

    PubMed

    Miller, A D; Austin, C M

    2006-03-01

    The complete mitochondrial DNA sequence was determined for the mantid shrimp Harpiosquilla harpax. These data demonstrate that the H. harpax mitochondrial genome is a 15,714 bp circular molecule and encodes the typical 37 metazoan mitochondrial genes (13 protein-coding, 22 tRNA, and two rRNA genes). The gene arrangement of H. harpax is consistent with that of the putative arthropod ancestral gene order as depicted by Limulus polyphemus. H. harpax was employed as an outgroup taxon for a phylogenetic investigation of the Decapoda using sequences from complete mitochondrial genomes. Whilst our results are largely in agreement with current taxonomic treatments, the relationships indicated among the reptantian decapods are novel. Our results provide strong statistical support for a sister-group relationship between the Achelata and the Astacida. These findings not only refute previous phylogenetic hypotheses, but also have serious implications for the interpretation of morphological and developmental evolution in the Decapoda. In addition we also investigated the effects of outgroup selection on the resolution of ingroup relationships. We found outgroup choice to significantly influence tree topology thus reinforcing the importance of appropriate outgroup selection in phylogenetic studies. PMID:16503278

  12. Ghost shrimps (Decapoda: Axiidea: Callianassidae) as producers of an Upper Miocene trace fossil association from sublittoral deposits of Lake Pannon (Vienna Basin, Slovakia)

    PubMed Central

    Hyžný, Matúš; Šimo, Vladimír; Starek, Dušan

    2015-01-01

    Numerous trace fossils are described from the Late Miocene sediments of the Bzenec Formation exposed at the Gbely section (the Vienna Basin, Slovakia). During deposition of the sediments the area was part of the large, long-lived brackish to freshwater Lake Pannon. Most of the trace fossils are attributed herein to Egbellichnus jordidegiberti igen et ispec. nov. and are interpreted as burrows produced by decapod crustaceans, specifically by a ghost shrimp of the family Callianassidae. This interpretation is based on two independent lines of evidence: environmental requirements of large bioturbators and the burrow morphology itself. The new ichnotaxon is distinguished from other related ichnotaxa by a combination of typically inclined (roughly at an angle of 45°) cylindrical burrows, absence of lining, and tunnels making loops or bends at approximately right angles. The burrow systems at Gbely document the survival of ghost shrimp long after the closure of all seaways and the origin of Lake Pannon. As today, no ghost shrimp are known from long-lived brackish lakes. Egbellichnus from Gbely is the only, although indirect, record of ghost shrimp from a brackish lake environment reported so far.

  13. A new genus and new species of Paguridae (Crustacea: Decapoda: Anomura) from shallow subtidal waters in Okinawa Island, the Ryukyu Islands, Japan.

    PubMed

    Komai, Tomoyuki

    2015-01-01

    During a survey on decapod crustacean fauna of shallow coral reefs and nearby environments in Okinawa Island, Ryukyu Archipelago, Japan, four specimens of a small but distinctive undescribed species of pagurid hermit crab, which could not be referred to any known genus, were collected. The new taxon, Eutrichopagurus shirakawai n. gen., n. sp., is described and illustrated herein. The new genus is characterized by the possession of 11 pairs of deeply quadriserial phyllobranchiate gills, the third maxilliped with well-developed crista dentata and one or two accessory teeth on the ischium, the presence of unpaired left gonopore in the female, the absence of paired first pleopods in the female, and the telson with prominent tuft of setae on the lateral margin of the posterior lobes; the male is unknown at present. It appears close to Trichopagurus de Saint Laurent, 1968, but the deeply quadriserial gills immediately distinguish Eutrichopagurus from Trichopagurus. The new genus is also compared with other genera characterized by the possession of 11 pairs of quadriserial phyllobranchiate gills and the lack of paired first pleopods in females. PMID:25781092

  14. Crystallization and X-ray diffraction studies of crustacean proliferating cell nuclear antigen

    PubMed Central

    Carrasco-Miranda, Jesus S.; Cardona-Felix, Cesar S.; Lopez-Zavala, Alonso A.; de-la-Re-Vega, Enrique; De la Mora, Eugenio; Rudińo-Pińera, Enrique; Sotelo-Mundo, Rogerio R.; Brieba, Luis G.

    2012-01-01

    Proliferating cell nuclear antigen (PCNA), a member of the sliding clamp family of proteins, interacts specifically with DNA replication and repair proteins through a small peptide motif called the PCNA-interacting protein or PIP box. PCNA is recognized as one of the key proteins involved in DNA metabolism. In the present study, the recombinant PCNA from Litopenaeus vannamei (LvPCNA) was heterologously overexpressed and purified using metal ion-affinity chromatography. Crystals suitable for diffraction grew overnight using the hanging-drop vapour-diffusion method. LvPCNA crystals belong to space group C2 with unit-cell parameters a = 144.6, b = 83.4, c = 74.3?Ĺ, ? = 117.6°. One data set was processed to 3?Ĺ resolution, with an overall R meas of 0.09 and a completeness of 93.3%. Initial phases were obtained by molecular replacement using a homology model of LvPCNA as the search model. Refinement and structural analysis are underway. This report is the first successful crystallographic analysis of a marine crustacean decapod shrimp (L. vannamei) proliferating cell nuclear antigen. PMID:23143251

  15. Differential acid-base regulation in various gills of the green crab Carcinus maenas: Effects of elevated environmental pCO2.

    PubMed

    Fehsenfeld, Sandra; Weihrauch, Dirk

    2013-01-01

    Euryhaline decapod crustaceans possess an efficient regulation apparatus located in the gill epithelia, providing a high adaptation potential to varying environmental abiotic conditions. Even though many studies focussed on the osmoregulatory capacity of the gills, acid-base regulatory mechanisms have obtained much less attention. In the present study, underlying principles and effects of elevated pCO(2) on acid-base regulatory patterns were investigated in the green crab Carcinus maenas acclimated to diluted seawater. In gill perfusion experiments, all investigated gills 4-9 were observed to up-regulate the pH of the hemolymph by 0.1-0.2 units. Anterior gills, especially gill 4, were identified to be most efficient in the equivalent proton excretion rate. Ammonia excretion rates mirrored this pattern among gills, indicating a linkage between both processes. In specimen exposed to elevated pCO(2) levels for at least 7 days, mimicking a future ocean scenario as predicted until the year 2300, hemolymph K(+) and ammonia concentrations were significantly elevated, and an increased ammonia excretion rate was observed. A detailed quantitative gene expression analysis revealed that upon elevated pCO(2) exposure, mRNA levels of transcripts hypothesized to be involved in ammonia and acid-base regulation (Rhesus-like protein, membrane-bound carbonic anhydrase, Na(+)/K(+)-ATPase) were affected predominantly in the non-osmoregulating anterior gills. PMID:23022520

  16. Rapid scavenging of jellyfish carcasses reveals the importance of gelatinous material to deep-sea food webs.

    PubMed

    Sweetman, Andrew K; Smith, Craig R; Dale, Trine; Jones, Daniel O B

    2014-12-01

    Jellyfish blooms are common in many oceans, and anthropogenic changes appear to have increased their magnitude in some regions. Although mass falls of jellyfish carcasses have been observed recently at the deep seafloor, the dense necrophage aggregations and rapid consumption rates typical for vertebrate carrion have not been documented. This has led to a paradigm of limited energy transfer to higher trophic levels at jelly falls relative to vertebrate organic falls. We show from baited camera deployments in the Norwegian deep sea that dense aggregations of deep-sea scavengers (more than 1000 animals at peak densities) can rapidly form at jellyfish baits and consume entire jellyfish carcasses in 2.5 h. We also show that scavenging rates on jellyfish are not significantly different from fish carrion of similar mass, and reveal that scavenging communities typical for the NE Atlantic bathyal zone, including the Atlantic hagfish, galatheid crabs, decapod shrimp and lyssianasid amphipods, consume both types of carcasses. These rapid jellyfish carrion consumption rates suggest that the contribution of gelatinous material to organic fluxes may be seriously underestimated in some regions, because jelly falls may disappear much more rapidly than previously thought. Our results also demonstrate that the energy contained in gelatinous carrion can be efficiently incorporated into large numbers of deep-sea scavengers and food webs, lessening the expected impacts (e.g. smothering of the seafloor) of enhanced jellyfish production on deep-sea ecosystems and pelagic-benthic coupling. PMID:25320167

  17. Ichnofauna from the Harbans Bed of the Badhaura Formation (Sterlitmakian), Rajasthan, India

    NASA Astrophysics Data System (ADS)

    Kulkarni, Kantimati G.; Borkar, Vidyadhar D.

    2014-03-01

    In the first ever systematic study of trace fossils from the Badhaura Formation, the authors described a nesting burrow, which they ascribed to a stomatopod. The purpose of this paper is two-fold: primarily, to document ichnofauna from (post-glacial marine late Palaeozoic rocks of peninsular India) the Badhaura Formation (Sterlitmakian) representing marine rocks deposited following the Late Palaeozoic glaciation and secondly to contribute to the data on post-glacial ichnofauna from constituent continents of the Gondwanaland. Trace fossils described here are from the Harbans Bed, the topmost lithounit of the Badhaura Formation. The ichnofauna includes Arenicolites tenuis, Beaconites isp., Curvolithus isp., Cylindrichnus concentricus, Didymaulichnus lyelli, Ophiomorpha isp., Palaeophycus tubularis, Planolites beverleyensis, P. montanus, Rosselia chonoides, R. socialis, Skolithos linearis, Taenidium cameronensis, Thalassinoides paradoxicus, Thalassinoides isp. and a flask-shaped brood chamber assigned to a stomatopod crustacean. This mixed assemblage is assigned to distal Skolithos ichnofacies and is suggestive of a period of relatively quiet, shallow water conditions of deposition. The ichnofauna, when viewed in context of peri-gondwanic ichnofaunas, mainly consisting of simple tracks and trails, from late Palaeozoic post-glacial deposits of other Gondwanan continents, is interesting due to dominance of domichnia. Profusion of brood chambers along with Thalassinoides in the Badhaura Formation validates the concept of pre-Mesozoic Thalassinoides being non-decapod in origin and suggestive of adaptive convergence.

  18. Cryptic assemblages in coral-rubble interstices along a terrestrial-sediment gradient

    NASA Astrophysics Data System (ADS)

    Takada, Y.; Abe, O.; Shibuno, T.

    2008-09-01

    The assemblage composition of cryptic mobile animals inhabiting coral rubble was sampled using mesh traps containing clean coral rubble, and used as indicators of land-based pollution at 14 sites in three coral lagoons at Ishigaki Island, southern Japan. Cluster analyses identified three groups of large mobile animal assemblages (molluscs, echinoderms, fishes, decapod and stomatopod crustaceans). Using a distance-based redundancy analysis (db-RDA) there was a significant relationship between the assemblage composition and environmental variables. The 1st axis of the db-RDA ordination was regarded as the land-based pollution gradient because of the strong relationship with silicate sediment, turbidity, and salinity, indicating effects of terrestrial-sediment runoff. Species response curves were derived from a plot of the number of individuals against the 1st axis of the db-RDA sites sample score. The response curves of Galathea mauritiana, an indicator species for the intermediate sites, were unimodal along the land-based pollution gradient. This study demonstrates the use of traps containing clean coral rubble for nondestructive quantitative sampling and environmental monitoring in coral lagoons, and their potential for monitoring changes in the reef environment.

  19. Effects of logging activities on ecological water quality indicators in the Berasau River, Johor, Malaysia.

    PubMed

    Nor Zaiha, A; Mohd Ismid, M S; Salmiati; Shahrul Azri, M S

    2015-08-01

    Influence of deforestation on biodiversity of aquatic organisms was investigated in a stream in the Ulu Sedili Forest Reserve. The stream was monitored five (5) times from December 2011 until December 2012 with 2-month intervals. Sampling of benthic communities was carried out using rectangular dip net while water quality study using a YSI ProPlus meter and the rest were done in the laboratory. Physicochemical parameters and water quality index (WQI) calculation showed no significant difference among the investigated events. WQI classified the Berasau River between Class II (good) to III (moderate) of river water quality. In total, 603 individuals representing 25 taxa that were recorded with Decapods from genus Macrobrabchium were widely distributed. Several intolerant taxa, especially Ephemeroptera and Odonata, were also observed in this river. According to Pearson's correlation analysis, the richness and diversity indices were generally influenced by water quality parameters represented by WQI (P?

  20. Cardiac and ventilatory responses of Crangon crangon to cadmium, copper and zinc

    NASA Astrophysics Data System (ADS)

    Price, R. K. J.; Uglow, R. F.

    1980-03-01

    The acute (30 min) responses of heart and scaphognathite activities of Crangon crangon on exposure to concentrations of 1 20 mg Cd, Cu or Zn 1-1 are increased beat frequencies. The relative magnitude of response (? f) is linearly related to immediate pretreatment frequency (f) and standardised responses (? fs) are given for f values of 70 and 100 beats min-1 for hearts and scaphognathites, respectively. ? fs values for each organ are also linearly related to test concentration for each metal. Qualitative changes to organ activities described include an increased incidence of scaphognathite reversals in concentrations of 5.0 mg Cu 1-1 and in 20.0 mg Zn 1-1. Chronic (13 days) exposure to incipient lethal levels of the test metals produced increases in scaphognathite rates of the Cd-treated animals and in heart and scaphognathite rates of the coppertreated animals. The general applicability of these methods to studies of pollution stress in decapods is discussed.

  1. Regulation of muscular contraction. Distribution of actin control and myosin control in the animal kingdom

    PubMed Central

    1975-01-01

    The control systems regulating muscle contraction in approximately 100 organisms have been categorized. Both myosin control and actin control operate simultaneously in the majority of invertebrates tested. These include insects, chelicerates, most crustaceans, annelids, priapulids, nematodes, and some sipunculids. Single myosin control is present in the muscles of molluscs, brachiopods, echinoderms, echiuroids, and nemertine worms. Single actin control was found in the fast muscles of decapods, in mysidacea, in a single sipunculid species, and in vertebrate striated muscles. Classification is based on functional tests that include measurements of the calcium dependence of the actomyosin ATPase activity in the presence and the absence of purified rabbit actin and myosin. In addition, isolated thin filaments and myosins were also analyzed. Molluscs lack actin control since troponin is not present in sufficient quantities. Even though the functional tests indicate the complete lack of myosin control in vertebrate striated muscle, it is difficult to exclude unambiguously the in vivo existence of this regulation. Both control systems have been found in animals from phyla which evolved early. We cannot ascribe any simple correlation between ATPase activity, muscle structure, and regulatory mechanisms. PMID:125778

  2. Freshwater scarcity effects on the aquatic macrofauna of a European Mediterranean-climate estuary.

    PubMed

    González-Ortegón, Enrique; Baldó, Francisco; Arias, Alberto; Cuesta, Jose A; Fernández-Delgado, Carlos; Vilas, César; Drake, Pilar

    2015-01-15

    In the Mediterranean-climate zone, recurrent drought events and increasing water demand generally lead to a decrease in freshwater input to estuaries. This water scarcity may alter the proper function of estuaries as nursery areas for marine species and as permanent habitat for estuarine species. A 12-year data set of the aquatic macrofauna (fish, decapod and mysid crustaceans) in a Mediterranean estuary (Guadalquivir estuary, South Spain) was analysed to test if water scarcity favours the nursery function of regional estuaries to the detriment of permanent estuarine inhabitants. Target species typically displayed a salinity-related distribution and estuarine salinisation in dry years resulted in a general upstream community displacement. However, annual densities of marine species were neither consistently higher in dry years nor estuarine species during wet years. Exceptions included the estuarine mysid Neomysis integer and the marine shrimp Crangon crangon, which were more abundant in wet and dry years, respectively. High and persistent turbidity, a collateral effect of water scarcity, altered both the structural (salinity-related pattern) and functional (key prey species and predator density) community characteristics, chiefly after the second drought period of the analysis. The observed high inter-year environmental variability, as well as species-specific effects of water scarcity, suggests that exhaustive and long-term sampling programmes will be required for rigorously monitoring the estuarine communities of the Mediterranean-climate region. PMID:25005237

  3. Seasonal habitat-use patterns of nekton in a tide-restricted and unrestricted New England salt marsh

    USGS Publications Warehouse

    Raposa, K.B.; Roman, C.T.

    2001-01-01

    Many New England salt marshes remain tide-restricted or are undergoing tidal restoration. Hydrologic manipulation of salt marshes affects marsh biogeochemistry and vegetation patterns, but responses by fishes and decapod crustaceans (nekton) remain unclear, This study examines nekton habitat-use patterns in the tide-restricted Hatches Harbor salt marsh (Provincetown, Massachusetts) relative to a downstream, unrestricted marsh. Nekton assemblages were sampled in tidal creek, marsh pool, and salt marsh surface habitats. Pools and creeks were sampled every two weeks for one year to account for seasonal variability, and the marsh surface was sampled at two-week intervals in summer and fall. Density, richness, and community composition of nekton in creek and marsh surface habitats were similar between the unrestricted and restricted marsh, but use of pools differed drastically on the two sides of the tide-restricting dike. In 95% of the cases tested, restricted marsh habitats provided equal or greater habitat value for nekton than the same habitat in the unrestricted marsh (based on density), suggesting that the restricted marsh did not provide a degraded habitat for most species. For some species, the restricted marsh provided nursery, breeding, and overwintering habitat during different seasons, and tidal restoration of this salt marsh must be approached with care to prevent losses of these valuable marsh functions.

  4. Reproductive traits of the symbiotic pea crab Austinotheres angelicus (Crustacea, Pinnotheridae) living in Saccostrea palmula (Bivalvia, Ostreidae), Pacific coast of Costa Rica

    PubMed Central

    Salas-Moya, Carolina; Mena, Sebastián; Wehrtmann, Ingo S.

    2014-01-01

    Abstract Pea crabs of the family Pinnotheridae exhibit a symbiotic life style and live associated with a variety of different marine organisms, especially bivalves. Despite the fact that pea crabs can cause serious problems in bivalve aquaculture, the available information about the ecology of these crabs from Central America is extremely limited. Therefore, the present study aimed to describe different reproductive features of the pinnotherid crab Austinotheres angelicus associated with the oyster Saccostrea palmula in the Golfo de Nicoya, Pacific coast of Costa Rica. Monthly sampling was conducted from April to December 2012. Average carapace width (CW) of the 47 analyzed ovigerous females was 7.62 mm. The species produced on average 2677 ± 1754 recently -extruded embryos with an average volume of 0.020 ± 0.003 mm3; embryo volume increased during embryogenesis by 21%, but did not vary significantly between developmental stages. Brood mass volume varied greatly (between 11.7 and 236.7 mm3), and increased significantly with female CW. Females invested on average 76.7% (minimum: 21.7%; maximum: 162.8%) of their body weight in brood production, which confirms a substantially higher energy allocation for embryo production in pinnotherid crabs compared to free-living decapods. PMID:25561840

  5. Reproductive traits of the symbiotic pea crab Austinotheresangelicus (Crustacea, Pinnotheridae) living in Saccostreapalmula (Bivalvia, Ostreidae), Pacific coast of Costa Rica.

    PubMed

    Salas-Moya, Carolina; Mena, Sebastián; Wehrtmann, Ingo S

    2014-01-01

    Pea crabs of the family Pinnotheridae exhibit a symbiotic life style and live associated with a variety of different marine organisms, especially bivalves. Despite the fact that pea crabs can cause serious problems in bivalve aquaculture, the available information about the ecology of these crabs from Central America is extremely limited. Therefore, the present study aimed to describe different reproductive features of the pinnotherid crab Austinotheresangelicus associated with the oyster Saccostreapalmula in the Golfo de Nicoya, Pacific coast of Costa Rica. Monthly sampling was conducted from April to December 2012. Average carapace width (CW) of the 47 analyzed ovigerous females was 7.62 mm. The species produced on average 2677 ± 1754 recently -extruded embryos with an average volume of 0.020 ± 0.003 mm(3); embryo volume increased during embryogenesis by 21%, but did not vary significantly between developmental stages. Brood mass volume varied greatly (between 11.7 and 236.7 mm(3)), and increased significantly with female CW. Females invested on average 76.7% (minimum: 21.7%; maximum: 162.8%) of their body weight in brood production, which confirms a substantially higher energy allocation for embryo production in pinnotherid crabs compared to free-living decapods. PMID:25561840

  6. Mesozooplankton community development at elevated CO2 concentrations: results from a mesocosm experiment in an Arctic fjord

    NASA Astrophysics Data System (ADS)

    Niehoff, B.; Knüppel, N.; Daase, M.; Czerny, J.; Boxhammer, T.

    2012-08-01

    The increasing CO2 concentration in the atmosphere caused by burning fossil fuels leads to increasing pCO2 and decreasing pH in the world oceans. These changes may have severe consequences for marine biota, especially in cold-water ecosystems due to higher solubility of CO2. However, studies on the response of mesozooplankton communities to elevated pCO2 are yet lacking. In order to test whether abundance and taxonomic composition change with pCO2, we have sampled nine mesocosms, which were deployed in Kongsfjorden, an Arctic fjord at Svalbard, and were adjusted to eight CO2 concentrations, initially ranging from 185 ?atm to 1420 ?atm. Samples were taken weekly over a six-week period with an Apstein net (55 ?m mesh size) in all mesocosms and the surrounding fjord. In addition, sediment trap samples, taken every second day in the mesocosms, were analyzed to account for losses due to vertical migration and mortality. The taxonomic analysis revealed that meroplanktonic larvae (cirripeds, polychaetes, bivalves, gastropod, and decapods) dominated in the mesocosms while copepods (Calanus spp., Oithona similis, Acartia longiremis and Microsetella norvegica) were found in lower abundances. In the fjord copepods prevailed for most of our study. With time, abundance and taxonomic composition developed similarly in all mesocosms; the pCO2 had no significant effect on the overall community structure. However, single taxa responded to elevated CO2 concentrations. The ratio of cirripedia nauplii to cypris larvae, the next developmental stage, in the sediment traps averaged over the entire experiment increased with pCO2 and this suggests that increased pCO2 may have delayed their development. Also, the number of bivalves, averaged over the experimental period, decreased significantly with increasing pCO2. The nature of the CO2 effect, either direct or indirect, remains open and needs to be addressed in future.

  7. Diet composition and resource partitioning in two small flatfish species in the German Bight

    NASA Astrophysics Data System (ADS)

    Schückel, S.; Sell, A.; Kröncke, I.; Reiss, H.

    2011-10-01

    Since the late 1980s, the small-sized non-commercial flatfish species solenette ( Buglossidium luteum) and scaldfish ( Arnoglossus laterna) have increased in abundance in the southern North Sea. Because these species are considered as possible competitors for prey of commercial flatfish, this study aimed at advancing knowledge of their feeding ecology. Between January 2009 and January 2010 stomach contents of solenette and scaldfish and benthic infauna were sampled seasonally in a study area in the German Bight. The objectives were to investigate the seasonal variability of feeding activity and diet composition of both flatfish species related to benthic prey availability. For both flatfish, the highest feeding activity was found in summer, at the same time that the highest prey densities occurred in the study area. A reduced feeding activity was observed during the winter of 2010, but not in the winter of 2009, probably related to higher 2009 water temperatures. In all seasons, diet composition of solenette was dominated by meiofauna, mainly harpacticoid copepods. Macrofauna prey species, namely juveniles of bivalves and echinoderms became important in spring. An increase in amphipods and cumaceans was found in the stomach contents during summer and autumn, simultaneously with their increased abundance in the benthic infauna. In contrast, polychaetes were rarely found in the diet, but dominated the infauna during all seasons. Diet composition of scaldfish was dominated by larger and mobile prey, and, during all seasons, was mainly comprised of crustaceans. Amphipods characterised the diet in both winters, while decapods such as Crangon spp. and Liocarcinus spp. were the dominant prey from spring to autumn. Additionally, juveniles of flatfish (Pleuronectids) and bivalves were found in the scaldfish diet in spring, replaced by cumaceans in summer. No dietary overlap between both flatfish species was found across seasons, indicating partitioning of prey resources between solenette and scaldfish. Their different feeding strategies and prey preferences, in turn were influenced by the seasonal variability of available prey.

  8. Cloning and Functional Analysis of Histones H3 and H4 in Nuclear Shaping during Spermatogenesis of the Chinese Mitten Crab, Eriocheir sinensis

    PubMed Central

    Wu, Jiang-Li; Kang, Xian-Jiang; Guo, Ming-Shen; Mu, Shu-Mei; Zhang, Zhao-Hui

    2015-01-01

    During spermatogenesis in most animals, the basic proteins associated with DNA are continuously changing and somatic-typed histones are partly replaced by sperm-specific histones, which are then successively replaced by transition proteins and protamines. With the replacement of sperm nuclear basic proteins, nuclei progressively undergo chromatin condensation. The Chinese Mitten Crab (Eriocheir sinensis) is also known as the hairy crab or river crab (phylum Arthropoda, subphylum Crustacea, order Decapoda, and family Grapsidae). The spermatozoa of this species are aflagellate, and each has a spherical acrosome surrounded by a cup-shaped nucleus, peculiar to brachyurans. An interesting characteristic of the E. sinensis sperm nucleus is its lack of electron-dense chromatin. However, its formation is not clear. In this study, sequences encoding histones H3 and H4 were cloned by polymerase chain reaction amplification. Western blotting indicated that H3 and H4 existed in the sperm nuclei. Immunofluorescence and ultrastructural immunocytochemistry demonstrated that histones H3 and H4 were both present in the nuclei of spermatogonia, spermatocytes, spermatids and mature spermatozoa. The nuclear labeling density of histone H4 decreased in sperm nuclei, while histone H3 labeling was not changed significantly. Quantitative real-time PCR showed that the mRNA expression levels of histones H3 and H4 were higher at mitotic and meiotic stages than in later spermiogenesis. Our study demonstrates that the mature sperm nuclei of E. sinensis contain histones H3 and H4. This is the first report that the mature sperm nucleus of E. sinensis contains histones H3 and H4. This finding extends the study of sperm histones of E. sinensis and provides some basic data for exploring how decapod crustaceans form uncondensed sperm chromatin. PMID:25993499

  9. Spatial structure of the meroplankton community along a Patagonian fjord - The role of changing freshwater inputs

    NASA Astrophysics Data System (ADS)

    Meerhoff, Erika; Tapia, Fabián J.; Castro, Leonardo R.

    2014-12-01

    Freshwater inputs are major drivers of circulation, hydrographic structure, and productivity patterns along estuarine systems. We assessed the degree to which meroplankton community structure in the Baker/Martinez fjord complex (Chilean Patagonia, 47.5°S) responds to spatial and temporal changes in hydrographic conditions driven by seasonal changes in Baker river outflow. Zooplankton and hydrographic measurements were conducted along the fjord in early spring (October) and late summer (February), when river outflow was minimal and maximal, respectively. Major meroplankton groups found on these surveys were larval barnacles, crabs, bivalves and gastropods. There was a clear change in community structure between October and February, explained by a switch in the numerically dominant group from barnacle to bivalve larvae. This change in community structure was related to changes in hydrographic structure along the fjord, which are mainly associated with seasonal changes in the Baker river outflow. A variance partition analysis showed no significant spatial trend that could account for the variation in meroplankton along the Martinez channel, whereas temporal variability and environmental variables accounted for 36.6% and 27.6% of the variance, respectively. When comparing meroplankton among the Baker and Martinez channels in October, changes in environmental variables explained 44.9% of total variance, whereas spatial variability accounted for 23.5%. Early and late-stage barnacle larvae (i.e. nauplii and cyprids) were more abundant in water with lower temperature, and higher dissolved oxygen and chlorophyll-a concentration, whereas bivalve larvae were more strongly associated to warmer waters. The seasonal shift in numerical dominance, from barnacle larvae in early spring to bivalve larvae in late summer, suggests that reproduction of these groups is triggered by substantially different sets of conditions, both in terms of hydrography and food availability. The analysis of a monthly zooplankton time series showed that barnacle nauplii were most abundant in spring, and one order of magnitude more abundant than cyprids. Larvae of decapods were most abundant in summer.

  10. 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 ?/Burs ? mRNA in TGC corresponds to protein contents of identified Burs ? 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

  11. 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 biotechnological approach that specifically tailors the molecular technological abilities to the management of each target group. PMID:22561950

  12. Expanding the Crustacean neuropeptidome using a multifaceted mass spectrometric approach.

    PubMed

    Ma, Mingming; Wang, Junhua; Chen, Ruibing; Li, Lingjun

    2009-05-01

    Jonah crab Cancer borealis is an excellent, long-served model organism for many areas of physiology, including the study of endocrinology and neurobiology. Characterizing the neuropeptides present in its nervous system provides the first critical step toward understanding the physiological roles of these complex molecules. Multiple mass spectral techniques were used to comprehensively characterize the neuropeptidome in C. borealis, including matrix-assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS), MALDI time-of-flight (TOF)/TOF MS and nanoflow liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (nanoLC-ESI-Q-TOF MS/MS). To enhance the detection signals and expand the dynamic range, direct tissue analysis, tissue extraction, capillary electrophoresis (CE) and off-line HPLC separation have also been employed. In total, 142 peptides were identified, including 85 previously known C. borealis peptides, 22 peptides characterized previously from other decapods, but new to this species, and 35 new peptides de novo sequenced for the first time in this study. Seventeen neuropeptide families were revealed including FMRFamide-related peptide (FaRP), allatostatin (A and B type), RYamide, orcokinin, orcomyotropin, proctolin, crustacean cardioactive peptide (CCAP), crustacean hyperglycemic hormone precursor-related peptide (CPRP), crustacean hyperglycemic hormone (CHH), corazonin, pigment-dispersing hormone (PDH), tachykinin, pyrokinin, SIFamide, red pigment concentrating hormone (RPCH) and HISGLYRamide. Collectively, our results greatly increase the number and expand the coverage of known C. borealis neuropeptides, and thus provide a stronger framework for future studies on the physiological roles played by these molecules in this important model organism. PMID:19222238

  13. Cloning and Functional Analysis of Histones H3 and H4 in Nuclear Shaping during Spermatogenesis of the Chinese Mitten Crab, Eriocheir sinensis.

    PubMed

    Wu, Jiang-Li; Kang, Xian-Jiang; Guo, Ming-Shen; Mu, Shu-Mei; Zhang, Zhao-Hui

    2015-01-01

    During spermatogenesis in most animals, the basic proteins associated with DNA are continuously changing and somatic-typed histones are partly replaced by sperm-specific histones, which are then successively replaced by transition proteins and protamines. With the replacement of sperm nuclear basic proteins, nuclei progressively undergo chromatin condensation. The Chinese Mitten Crab (Eriocheir sinensis) is also known as the hairy crab or river crab (phylum Arthropoda, subphylum Crustacea, order Decapoda, and family Grapsidae). The spermatozoa of this species are aflagellate, and each has a spherical acrosome surrounded by a cup-shaped nucleus, peculiar to brachyurans. An interesting characteristic of the E. sinensis sperm nucleus is its lack of electron-dense chromatin. However, its formation is not clear. In this study, sequences encoding histones H3 and H4 were cloned by polymerase chain reaction amplification. Western blotting indicated that H3 and H4 existed in the sperm nuclei. Immunofluorescence and ultrastructural immunocytochemistry demonstrated that histones H3 and H4 were both present in the nuclei of spermatogonia, spermatocytes, spermatids and mature spermatozoa. The nuclear labeling density of histone H4 decreased in sperm nuclei, while histone H3 labeling was not changed significantly. Quantitative real-time PCR showed that the mRNA expression levels of histones H3 and H4 were higher at mitotic and meiotic stages than in later spermiogenesis. Our study demonstrates that the mature sperm nuclei of E. sinensis contain histones H3 and H4. This is the first report that the mature sperm nucleus of E. sinensis contains histones H3 and H4. This finding extends the study of sperm histones of E. sinensis and provides some basic data for exploring how decapod crustaceans form uncondensed sperm chromatin. PMID:25993499

  14. Phylogeny and Evolutionary Patterns in the Dwarf Crayfish Subfamily (Decapoda: Cambarellinae)

    PubMed Central

    Pedraza-Lara, Carlos; Doadrio, Ignacio; Breinholt, Jesse W.; Crandall, Keith A.

    2012-01-01

    The Dwarf crayfish or Cambarellinae, is a morphologically singular subfamily of decapod crustaceans that contains only one genus, Cambarellus. Its intriguing distribution, along the river basins of the Gulf Coast of United States (Gulf Group) and into Central México (Mexican Group), has until now lacked of satisfactory explanation. This study provides a comprehensive sampling of most of the extant species of Cambarellus and sheds light on its evolutionary history, systematics and biogeography. We tested the impact of Gulf Group versus Mexican Group geography on rates of cladogenesis using a maximum likelihood framework, testing different models of birth/extinction of lineages. We propose a comprehensive phylogenetic hypothesis for the subfamily based on mitochondrial and nuclear loci (3,833 bp) using Bayesian and Maximum Likelihood methods. The phylogenetic structure found two phylogenetic groups associated to the two main geographic components (Gulf Group and Mexican Group) and is partially consistent with the historical structure of river basins. The previous hypothesis, which divided the genus into three subgenera based on genitalia morphology was only partially supported (P?=?0.047), resulting in a paraphyletic subgenus Pandicambarus. We found at least two cases in which phylogenetic structure failed to recover monophyly of recognized species while detecting several cases of cryptic diversity, corresponding to lineages not assigned to any described species. Cladogenetic patterns in the entire subfamily are better explained by an allopatric model of speciation. Diversification analyses showed similar cladogenesis patterns between both groups and did not significantly differ from the constant rate models. While cladogenesis in the Gulf Group is coincident in time with changes in the sea levels, in the Mexican Group, cladogenesis is congruent with the formation of the Trans-Mexican Volcanic Belt. Our results show how similar allopatric divergence in freshwater organisms can be promoted through diverse vicariant factors. PMID:23155379

  15. Recovery of rhythmic activity in a central pattern generator: analysis of the role of neuromodulator and activity-dependent mechanisms

    PubMed Central

    Zhang, Yili; Golowasch, Jorge

    2015-01-01

    The pyloric network of decapods crustaceans can undergo dramatic rhythmic activity changes. Under normal conditions the network generates low frequency rhythmic activity that depends obligatorily on the presence of neuromodulatory input from the central nervous system. When this input is removed (decentralization) the rhythmic activity ceases. In the continued absence of this input, periodic activity resumes after a few hours in the form of episodic bursting across the entire network that later turns into stable rhythmic activity that is nearly indistinguishable from control (recovery). It has been proposed that an activity-dependent modification of ionic conductance levels in the pyloric pacemaker neuron drives the process of recovery of activity. Previous modeling attempts have captured some aspects of the temporal changes observed experimentally, but key features could not be reproduced. Here we examined a model in which slow activity-dependent regulation of ionic conductances and slower neuromodulator-dependent regulation of intracellular Ca2+ concentration reproduce all the temporal features of this recovery. Key aspects of these two regulatory mechanisms are their independence and their different kinetics. We also examined the role of variability (noise) in the activity-dependent regulation pathway and observe that it can help to reduce unrealistic constraints that were otherwise required on the neuromodulator-dependent pathway. We conclude that small variations in intracellular Ca2+ concentration, a Ca2+ uptake regulation mechanism that is directly targeted by neuromodulator-activated signaling pathways, and variability in the Ca2+ concentration sensing signaling pathway can account for the observed changes in neuronal activity. Our conclusions are all amenable to experimental analysis. PMID:21573963

  16. Distinctive stable isotope ratios in important zooplankton species in relation to estuarine salinity gradients: Potential tracer of fish migration

    NASA Astrophysics Data System (ADS)

    Suzuki, Keita W.; Kasai, Akihide; Isoda, Takane; Nakayama, Kouji; Tanaka, Masaru

    2008-07-01

    To assess the potential of stable isotope ratios as an indicator of fish migration within estuaries, stable isotope ratios in important zooplankton species were analyzed in relation to estuarine salinity gradients. Gut contents from migratory juveniles of the euryhaline marine fish Lateolabrax japonicus were examined along the Chikugo River estuary of the Ariake Sea, which has the most developed estuarine turbidity maximum (ETM) in Japan. Early juveniles in March and April preyed primarily on two copepod species; Sinocalanus sinensis at lower salinities and Acartia omorii at higher salinities. Late juveniles (standard length > 40 mm) at lower salinities preyed exclusively on the mysid Acanthomysis longirostris until July and complementarily on the decapod Acetes japonicus in August. These prey species were collected along the estuary during the spring-summer seasons of 2003 and 2004, and their carbon and nitrogen stable isotope ratios ( ?13C and ?15N) were evaluated. The ?13C values of prey species were distinct from each other and were primarily depleted within and in close proximity to the ETM (salinity < 10); S. sinensis (-26.6‰) < Acanthomysis longirostris (-23.3‰) < Acartia omorii (-21.1‰) < Acetes japonicus (-18.5‰). The overall gradient of ?13C with salinity occurred for all prey species and showed minor temporal fluctuations, while it was not directly influenced by the ?13C values in particulate organic matter along the estuary. In contrast to ?13C, the ?15N values of prey species did not exhibit any clear relationship with salinity. The present study demonstrated that ?13C has the potential for application as a tracer of fish migration into lower salinity areas including the ETM.

  17. Spatial variability in the structure of intertidal crab and gastropod assemblages within the Seychelles Archipelago (Indian Ocean)

    NASA Astrophysics Data System (ADS)

    Smale, Dan A.; Barnes, David K. A.; Barnes, Richard S. K.; Smith, David J.; Suggett, David J.

    2012-04-01

    Tropical nearshore ecosystems represent global hotspots of marine biodiversity and endemism but are often poorly understood and impacted by human activities. The Seychelles Archipelago (Western Indian Ocean) sustains a wealth of marine life, much of which is threatened by rapid development associated with tourism and climate change. Six marine parks exist within the Archipelago, but their biodiversity value and ecological health are poorly known, especially with regards to non-fish and coral species. Here we investigate spatial patterns of littoral biodiversity on 6 islands, 5 of which were granitic and within marine parks, including the first surveys of Curieuse and Ile Cocos. Our surveys formed a nested sampling design, to facilitate an examination of variability in species richness, faunal abundance, taxonomic distinctness and assemblage composition at multiple spatial scales, from islands (> 100 s km) to quadrats (metres). We identified (mostly to species) and enumerated two target taxa, brachyuran decapod crustaceans and gastropod molluscs, and recorded over 8300 individuals belonging to over 150 species. Crabs and gastropods exhibited different patterns of spatial variability, as crab assemblages were generally more distinct between islands, while gastropod assemblages were markedly variable at the smallest spatial scales of 'patch' and 'quadrat'. Intertidal biodiversity was greatest on Curieuse Island and least at Desroches, the latter was being the only coral atoll we surveyed and thereby differing in its geological and ecological context. We discuss likely drivers of these biodiversity patterns and highlight urgently-needed research directions. Our assessment of the status of poorly-known invertebrate assemblages across the Seychelles will complement more extensive surveys of coral and fish assemblages and, in doing so, provide a useful baseline for monitoring the effects of key stressors in the region, such as coastal development and climate change.

  18. From embryo to adult: persistent neurogenesis and apoptotic cell death shape the lobster deutocerebrum.

    PubMed

    Harzsch, S; Miller, J; Benton, J; Beltz, B

    1999-05-01

    Neuronal plasticity and synaptic remodeling play important roles during the development of the invertebrate nervous system. In addition, structural neuroplasticity as a result of long-term environmental changes, behavioral modifications, age, and experience have been demonstrated in the brains of sexually mature insects. In adult vertebrates, persistent neurogenesis is found in the granule cell layer of the mammalian hippocampus and the subventricular zone, as well as in the telencephalon of songbirds, indicating that persistent neurogenesis, which is presumably related to plasticity and learning, may be an integral part of the normal biology of the mature brain. In decapod crustaceans, persistent neurogenesis among olfactory projection neurons is a common principle that shapes the adult brain, indicating a remarkable degree of life-long structural plasticity. The present study closes a gap in our knowledge of this phenomenon by describing the continuous cell proliferation and gradual displacement of proliferation domains in the central olfactory pathway of the American lobster Homarus americanus from early embryonic through larval and juvenile stages into adult life. Neurogenesis in the deutocerebrum was examined by the in vivo incorporation of bromodeoxyuridine, and development and structural maturation of the deutocerebral neuropils were studied using immunohistochemistry against Drosophila synapsin. The role of apoptotic cell death in shaping the developing deutocerebrum was studied using the terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling method, combined with immunolabeling using an antiphospho histone H3 mitosis marker. Our results indicate that, in juvenile and adult lobsters, birth and death of olfactory interneurons occur in parallel, suggesting a turnover of these cells. When the persistent neurogenesis and concurrent death of interneurons in the central olfactory pathway of the crustacean brain are taken into account with the life-long turnover of olfactory receptor cells in crustacean antennules, a new, highly dynamic picture of olfaction in crustaceans emerges. PMID:10212307

  19. Expression of ionotropic receptors in terrestrial hermit crab's olfactory sensory neurons

    PubMed Central

    Groh-Lunow, Katrin C.; Getahun, Merid N.; Grosse-Wilde, Ewald; Hansson, Bill S.

    2015-01-01

    Coenobitidae are one out of at least five crustacean lineages which independently succeeded in the transition from water to land. This change in lifestyle required adaptation of the peripheral olfactory organs, the antennules, in order to sense chemical cues in the new terrestrial habitat. Hermit crab olfactory aesthetascs are arranged in a field on the distal segment of the antennular flagellum. Aesthetascs house approximately 300 dendrites with their cell bodies arranged in spindle-like complexes of ca. 150 cell bodies each. While the aesthetascs of aquatic crustaceans have been shown to be the place of odor uptake and previous studies identified ionotropic receptors (IRs) as the putative chemosensory receptors expressed in decapod antennules, the expression of IRs besides the IR co-receptors IR25a and IR93a in olfactory sensory neurons (OSNs) has not been documented yet. Our goal was to reveal the expression and distribution pattern of non-co-receptor IRs in OSNs of Coenobita clypeatus, a terrestrial hermit crab, with RNA in situ hybridization. We expanded our previously published RNAseq dataset, and revealed 22 novel IR candidates in the Coenobita antennules. We then used RNA probes directed against three different IRs to visualize their expression within the OSN cell body complexes. Furthermore we aimed to characterize ligand spectra of single aesthetascs by recording local field potentials and responses from individual dendrites. This also allowed comparison to functional data from insect OSNs expressing antennal IRs. We show that this orphan receptor subgroup with presumably non-olfactory function in insects is likely the basis of olfaction in terrestrial hermit crabs. PMID:25698921

  20. Feeder pipes - Expression of the uppermost plumbing system in Oligocene methane-seep deposits, Washington State, USA

    NASA Astrophysics Data System (ADS)

    Zwicker, Jennifer; Smrzka, Daniel; Gier, Susanne; Goedert, James; Peckmann, Jörn

    2015-04-01

    Plumbing systems of methane seeps are complex pathways along which hydrocarbon-rich fluids migrate upward through the marine sedimentary column. Seeps commonly maintain fluid flow over long periods of time, providing a steady supply of methane to shallow sediments and the water column. At greater sediment depths, fluid transport is facilitated by faults and conduits, which enable migration of fluids sourced from deep hydrocarbon reservoirs. In the shallow subsurface, plumbing systems may become successively filled by authigenic carbonates, whose precipitation is partly triggered by sulfate-dependent anaerobic oxidation of methane (AOM). To expand our knowledge on the uppermost plumbing network of ancient seeps, this work investigates fluid conduits that were mineralized by a distinct succession of authigenic mineral phases. These mineralized conduits, which occur below an Oligocene seep deposit from the Lincoln Creek Formation in Washington State, are referred to as feeder pipes here. The concentrically-zoned feeder pipes are 2 to 3 cm in diameter. The mineral phase that formed first is matrix micrite, making up the outer part of pipes. Toward the center, pipes are filled by clear, banded and botryoidal aragonite cement, which is intercalated with yellow aragonite cement. The innermost portions of the pipes are filled by either pipe-filling micrite, microspar, or brownish calcite. The observed paragenetic sequences archive successions of various biogeochemical processes. Clear and yellow aragonite cements are distinctly depleted in 13C, revealing that their formation was favored by AOM. In contrast, later phases including brownish calcite and microspar are enriched in 13C, pointing to precipitation from fluids affected by methanogenesis. Their size and morphology indicate that the pipes were initially produced by seep-dwelling, burrowing organisms. The burrows subsequently acted as preferred fluid pathways. Possible producers of the burrows include various bivalves and callianassid decapods. Based on petrography and stable isotopes patterns, we conclude that the pipes facilitated seepage of methane-rich fluids to the sediment-water interface.

  1. 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 undescribed species, reflecting our knowledge of host diversity patterns. PMID:22558143

  2. An insulin-like growth factor found in hepatopancreas implicates carbohydrate metabolism of the blue crab Callinectes sapidus.

    PubMed

    Chung, J Sook

    2014-04-01

    Hyperglycemia that is caused by the release of crustacean hyperglycemic hormone (CHH) from the sinus gland to hemolymph is one of the hallmark physiological phenomena, occurring in decapod crustaceans experiencing stressful conditions. However, the mechanism(s) by which such elevated glucose levels return to resting levels is still unknown. Interestingly, noted is a difference in the clearance rate of hemolymph glucose between adult females and adult males of the blue crab, Callinectes sapidus: the former with more rapid clearance than the latter. The presence of an endogenous-insulin-like molecule is suggested in C. sapidus because an injection of bovine insulin, significantly reduces the levels of hemolymph glucose that were previously elevated by emersion stress or the glucose injection. Using 5' and 3' RACE, the full-length cDNA of an insulin-like molecule is isolated from the hepatopancreas of an adult female C. sapidus and shows the same putative sequence of an insulin-like androgenic gland factor (IAG) but differs in 5' and 3' UTR sequences. A knock-down study using five injections of double-stranded RNA of CasIAG-hep (dsRNA-CasIAG-hep, 10?g/injection) over a 10-day period reduces CasIAG-hep expression by ?50%. The levels of hemolymph glucose are also kept higher in dsRNA-CasIAG-hep injected group than those treated with dsRNA-green fluorescent protein (dsRNA-IAG-hep) or saline. Most importantly, the hepatopancreas of dsRNA-CasIAG-hep injected animals contains amounts of carbohydrate (glucose, trehalose, and glycogen) significantly lower than those of control groups, indicating that the function of CasIAG-hep in carbohydrate metabolism in crustaceans is similar to carbohydrate metabolism in vertebrates. PMID:24503150

  3. An antibody to recombinant crustacean hyperglycaemic hormone of Nephrops norvegicus cross-reacts with neuroendocrine organs of several taxa of malacostracan Crustacea.

    PubMed

    Giulianini, P G; Pandolfelli, N; Lorenzon, S; Ferrero, E A; Edomi, P

    2002-02-01

    The crustacean hyperglycaemic hormones (cHHs) are multifunctional neuropeptides that play a central role in the physiology of crustaceans. A partial cDNA coding for cHH of the Norway lobster, Nephrops norvegicus, was cloned; this cDNA was fused to glutathione- S-transferase (GST) to obtain a recombinant fusion protein that was used to raise a rabbit antiserum and to perform a biological assay. The specificity of the purified antibody was demonstrated by means of Western blotting. To validate the specificity of the purified antibody to the cHH of N. norvegicus and its cross-reactivity with other species, we performed standard immunocytochemistry of the eyestalk on: (1) paraffin sections of the decapod species N. norvegicus, Munida rugosa and Astacus leptodactylus and of the stomatopod Squilla mantis; (2) semithin resin sections of N. norvegicus and Palaemon elegans; (3) ultrathin sections of N. norvegicus sinus gland (transmission electron microscopy studies). The pattern of immunoreactivity shown by N. norvegicus eyestalk sections conforms to distribution, relative amount and ultrastructural features of cHH-containing neurons and nerve endings as reported in the previous literature. In all the crustacean species examined, the antibody marks precisely the X organ-sinus gland complex and unspecific staining is completely lacking. In addition, its specific cross-reaction by immunoprecipitation depletes shrimp eyestalk extract of hyperglycaemic activity in an in vivo bioassay. The results obtained show a cHH-specific molecular recognition despite the fact that the species tested belong to systematic groups increasingly remote in the phylogenetic tree. The antibody could be used for advancing our knowledge on cHH activity in a variety of crustacean species, e.g. for monitoring reproductive and stress conditions. PMID:11845331

  4. Characterization of a prawn OA/TA receptor in Xenopus oocytes suggests functional selectivity between octopamine and tyramine.

    PubMed

    Jezzini, Sami H; Reyes-Colón, Dalynés; Sosa, María A

    2014-01-01

    Here we report the characterization of an octopamine/tyramine (OA/TA or TyrR1) receptor (OA/TAMac) cloned from the freshwater prawn, Macrobrachium rosenbergii, an animal used in the study of agonistic social behavior. The invertebrate OA/TA receptors are seven trans-membrane domain G-protein coupled receptors that are related to vertebrate adrenergic receptors. Behavioral studies in arthropods indicate that octopaminergic signaling systems modulate fight or flight behaviors with octopamine and/or tyramine functioning in a similar way to the adrenalins in vertebrate systems. Despite the importance of octopamine signaling in behavioral studies of decapod crustaceans there are no functional data available for any of their octopamine or tyramine receptors. We expressed OA/TAMac in Xenopus oocytes where agonist-evoked trans-membrane currents were used as readouts of receptor activity. The currents were most effectively evoked by tyramine but were also evoked by octopamine and dopamine. They were effectively blocked by yohimbine. The electrophysiological approach we used enabled the continuous observation of complex dynamics over time. Using voltage steps, we were able to simultaneously resolve two types of endogenous currents that are affected over different time scales. At higher concentrations we observe that octopamine and tyramine can produce different and opposing effects on both of these currents, presumably through the activity of the single expressed receptor type. The pharmacological profile and apparent functional-selectivity are consistent with properties first observed in the OA/TA receptor from the insect Drosophila melanogaster. As the first functional data reported for any crustacean OA/TA receptor, these results suggest that functional-selectivity between tyramine and octopamine is a feature of this receptor type that may be conserved among arthropods. PMID:25350749

  5. Trophodynamics and distribution of silver in a Patagonia mountain lake.

    PubMed

    Revenga, J E; Campbell, L M; Kyser, K; Klassen, K; Arribére, M A; Ribeiro Guevara, S

    2011-04-01

    Silver (Ag) ions are among the most toxic metallic ions to aquatic biota. In southern Argentina, fish from Patagonian lakes have liver Ag concentrations [Ag] among the highest ever reported globally. Silver concentration in phytoplankton from Lake Moreno (1.82±3.00?gg(-1) dry weight, DW) was found to be significantly higher than [Ag] in zooplankton (0.25±0.13?gg(-1)). Values in snails and decapods (0.60±0.28?gg(-1) and 0.47±0.03?gg(-1) respectively), were higher than in insect larvae (0.28±0.39?gg(-1) for Trichoptera). We examined trophic transfer of Ag in the biota using stable nitrogen and carbon isotopes ratios (?(15)N and ?(13)C respectively). Silver concentrations in the biota of Lake Moreno were not associated with any particular C source, as assessed by ?(13)C. Hepatic [Ag] significantly increased with trophic position, as measured by ?(15)N, within the brook trout sample set. Biodilution of Ag was observed between primary producers and small forage fish when whole body [Ag] was analyzed. Nevertheless, when considering whole food web biomagnification and hepatic [Ag] of top predator fish, a significant positive regression was found between [Ag] and trophic position, as measured by ?(15)N. The importance of species-specific and tissue-specific considerations to obtain more information on Ag trophodynamics than that usually presented in the literature is shown. To the best of our knowledge, this is the first study in assessing Ag trophodynamics and tissue-specific biomagnification in a whole freshwater food web. PMID:21216430

  6. Evolution of pigment-dispersing factor neuropeptides in panarthropoda: Insights from onychophora (velvet worms) and tardigrada (water bears).

    PubMed

    Mayer, Georg; Hering, Lars; Stosch, Juliane M; Stevenson, Paul A; Dircksen, Heinrich

    2015-09-01

    Pigment-dispersing factor (PDF) denotes a conserved family of homologous neuropeptides present in several invertebrate groups, including mollusks, nematodes, insects, and crustaceans (referred to here as pigment-dispersing hormone [PDH]). With regard to their encoding genes (pdf, pdh), insects possess only one, nematodes two, and decapod crustaceans up to three, but their phylogenetic relationship is unknown. To shed light on the origin and diversification of pdf/pdh homologs in Panarthropoda (Onychophora?+?Tardigrada?+?Arthropoda) and other molting animals (Ecdysozoa), we analyzed the transcriptomes of five distantly related onychophorans and a representative tardigrade and searched for putative pdf homologs in publically available genomes of other protostomes. This revealed only one pdf homolog in several mollusk and annelid species; two in Onychophora, Priapulida, and Nematoda; and three in Tardigrada. Phylogenetic analyses suggest that the last common ancestor of Panarthropoda possessed two pdf homologs, one of which was lost in the arthropod or arthropod/tardigrade lineage, followed by subsequent duplications of the remaining homolog in some taxa. Immunolocalization of PDF-like peptides in six onychophoran species, by using a broadly reactive antibody that recognizes PDF/PDH peptides in numerous species, revealed an elaborate system of neurons and fibers in their central and peripheral nervous systems. Large varicose projections in the heart suggest that the PDF neuropeptides functioned as both circulating hormones and locally released transmitters in the last common ancestor of Onychophora and Arthropoda. The lack of PDF-like-immunoreactive somata associated with the onychophoran optic ganglion conforms to the hypothesis that onychophoran eyes are homologous to the arthropod median ocelli. J. Comp. Neurol. 523:1865-1885, 2015 © 2015 Wiley Periodicals, Inc. PMID:25722044

  7. Evolution of pigment-dispersing factor neuropeptides in panarthropoda: Insights from onychophora (velvet worms) and tardigrada (water bears).

    PubMed

    Mayer, Georg; Hering, Lars; Stosch, Juliane M; Stevenson, Paul A; Dircksen, Heinrich

    2015-09-01

    Pigment-dispersing factor (PDF) denotes a conserved family of homologous neuropeptides present in several invertebrate groups, including mollusks, nematodes, insects, and crustaceans (referred to here as pigment-dispersing hormone [PDH]). With regard to their encoding genes (pdf, pdh), insects possess only one, nematodes two, and decapod crustaceans up to three, but their phylogenetic relationship is unknown. To shed light on the origin and diversification of pdf/pdh homologs in Panarthropoda (Onychophora?+?Tardigrada?+?Arthropoda) and other molting animals (Ecdysozoa), we analyzed the transcriptomes of five distantly related onychophorans and a representative tardigrade and searched for putative pdf homologs in publically available genomes of other protostomes. This revealed only one pdf homolog in several mollusk and annelid species; two in Onychophora, Priapulida, and Nematoda; and three in Tardigrada. Phylogenetic analyses suggest that the last common ancestor of Panarthropoda possessed two pdf homologs, one of which was lost in the arthropod or arthropod/tardigrade lineage, followed by subsequent duplications of the remaining homolog in some taxa. Immunolocalization of PDF-like peptides in six onychophoran species, by using a broadly reactive antibody that recognizes PDF/PDH peptides in numerous species, revealed an elaborate system of neurons and fibers in their central and peripheral nervous systems. Large varicose projections in the heart suggest that the PDF neuropeptides functioned as both circulating hormones and locally released transmitters in the last common ancestor of Onychophora and Arthropoda. The lack of PDF-like-immunoreactive somata associated with the onychophoran optic ganglion conforms to the hypothesis that onychophoran eyes are homologous to the arthropod median ocelli. J. Comp. Neurol. 523:1865-1885, 2015 © 2015 Wiley Periodicals, Inc. PMID:26190200

  8. Modeling prey consumption by native and non-native piscivorous fishes: implications for competition and impacts on shared prey in an ultraoligotrophic lake in Patagonia

    USGS Publications Warehouse

    Juncos, Romina; Beauchamp, David A.; Viglianoc, Pablo H.

    2013-01-01

    We examined trophic interactions of the nonnative salmonids Rainbow Trout Oncorhynchus mykiss, Brown Trout Salmo trutta, and Brook Trout Salvelinus fontinalisand the main native predator Creole Perch Percichthys trucha in Lake Nahuel Huapi (Patagonia, Argentina) to determine the relative impact of each predator on their forage base and to evaluate the potential vulnerability of each predator to competitive impacts by the others. Using bioenergetics simulations, we demonstrated the overall importance of galaxiids and decapods to the energy budgets of nonnative salmonids and Creole Perch. Introduced salmonids, especially Rainbow Trout, exerted considerably heavier predatory demands on shared resources than did the native Creole Perch on both a per capita basis and in terms of relative population impacts. Rainbow Trout consumed higher quantities and a wider size range of Small Puyen (also known as Inanga) Galaxias maculatus than the other predators, including early pelagic life stages of that prey; as such, this represents an additional source of mortality for the vulnerable early life stages of Small Puyen before and during their transition from pelagic to benthic habitats. All predators were generally feeding at high feeding rates (above 40% of their maximum physiological rates), suggesting that competition for prey does not currently limit either Creole Perch or the salmonids in this lake. This study highlights the importance of keystone prey for the coexistence of native species with nonnative top predators. It provides new quantitative and qualitative evidence of the high predation pressure exerted on Small Puyen, the keystone prey species, during the larval to juvenile transition from pelagic to littoral-benthic habitat in Patagonian lakes. This study also emphasizes the importance of monitoring salmonid and Creole Perch population dynamics in order to detect signs of potential impacts through competition and shows the need to carefully consider the rationale behind any additional trout stocking.

  9. Antarctic Crabs: Invasion or Endurance?

    PubMed Central

    Griffiths, Huw J.; Whittle, Rowan J.; Roberts, Stephen J.; Belchier, Mark; Linse, Katrin

    2013-01-01

    Recent scientific interest following the “discovery” of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This “invasion hypothesis” suggests that decapod crabs were driven out of Antarctica 40–15 million years ago and are only now returning as “warm” enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60°S. All are restricted to waters warmer than 0°C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day “crab invasion”. We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the “invasion hypothesis”. PMID:23843974

  10. Inorganic carbon fixation by chemosynthetic ectosymbionts and nutritional transfers to the hydrothermal vent host-shrimp Rimicaris exoculata

    PubMed Central

    Ponsard, Julie; Cambon-Bonavita, Marie-Anne; Zbinden, Magali; Lepoint, Gilles; Joassin, André; Corbari, Laure; Shillito, Bruce; Durand, Lucile; Cueff-Gauchard, Valérie; Compčre, Philippe

    2013-01-01

    The shrimp Rimicaris exoculata dominates several hydrothermal vent ecosystems of the Mid-Atlantic Ridge and is thought to be a primary consumer harbouring a chemoautotrophic bacterial community in its gill chamber. The aim of the present study was to test current hypotheses concerning the epibiont's chemoautotrophy, and the mutualistic character of this association. In-vivo experiments were carried out in a pressurised aquarium with isotope-labelled inorganic carbon (NaH13CO3 and NaH14CO3) in the presence of two different electron donors (Na2S2O3 and Fe2+) and with radiolabelled organic compounds (14C-acetate and 3H-lysine) chosen as potential bacterial substrates and/or metabolic by-products in experiments mimicking transfer of small biomolecules from epibionts to host. The bacterial epibionts were found to assimilate inorganic carbon by chemoautotrophy, but many of them (thick filaments of epsilonproteobacteria) appeared versatile and able to switch between electron donors, including organic compounds (heterotrophic acetate and lysine uptake). At least some of them (thin filamentous gammaproteobacteria) also seem capable of internal energy storage that could supply chemosynthetic metabolism for hours under conditions of electron donor deprivation. As direct nutritional transfer from bacteria to host was detected, the association appears as true mutualism. Import of soluble bacterial products occurs by permeation across the gill chamber integument, rather than via the digestive tract. This first demonstration of such capabilities in a decapod crustacean supports the previously discarded hypothesis of transtegumental absorption of dissolved organic matter or carbon as a common nutritional pathway. PMID:22914596

  11. Potential respiration estimated by electron transport system activity in deep-sea suprabenthic crustaceans off Balearic Islands (Western Mediterranean)

    NASA Astrophysics Data System (ADS)

    Herrera, A.; Gómez, M.; Packard, T. T.; Reglero, P.; Blanco, E.; Barberá-Cebrián, C.

    2014-10-01

    ETS is an acronym for the activity of the respiratory electron transport system; the ETS assay is a biochemical method for estimating the “potential” respiration (?). We apply this technique to suprabenthic species captured at three depths (250 m, 650 m and 850 m) in two different locations: Cabrera (Algerian subbasin) and Sóller (Balearic subbasin) during the IDEADOS survey during summer 2010. The aim of this study was to compare specific ? between areas and between three depths to identify differences in the suprabenthos physiological state related to nutritional conditions. Specific ?, expressed in unit of ?l O2 h- 1 mg prot- 1 was not significantly different between species. Mean values were for the decapods: Plesionika heterocarpus, 8.4 ± 7.9; Gennadas elegans, 8.3 ± 2.9; and Sergestes arcticus 7.3 ± 4.6. Within the euphausiids specific ? averaged 6.5 ± 4.2 for Thysanopoda aequalis and 9.8 ± 5.1 for Meganyctiphanes norvegica; while for the mysids it ranged from 7.7 ± 4.4 for Boreomysis arctica and 2.1 ± 0.6 for Eucopia unguiculata. The comparison of specific potential respiration (?), with the pooling of the data of all the species, showed differences between the two locations, being higher in Cabrera. However, no significant differences between the different depths of each locality were found. The slope of the log ?-log biomass plot was 0.93 ± 0.09 for Cabrera and 0.64 ± 0.11 in Sóller. We interpret these differences as indicating that the suprabenthos in the Cabrera area, as compared to the Sóller area, has been well-nourished.

  12. Susceptibility to infection and pathogenicity of White Spot Disease (WSD) in non-model crustacean host taxa from temperate regions.

    PubMed

    Bateman, K S; Tew, I; French, C; Hicks, R J; Martin, P; Munro, J; Stentiford, G D

    2012-07-01

    Despite almost two decades since its discovery, White Spot Disease (WSD) caused by White Spot Syndrome Virus (WSSV) is still considered the most significant known pathogen impacting the sustainability and growth of the global penaeid shrimp farming industry. Although most commonly associated with penaeid shrimp farmed in tropical regions, the virus is also able to infect, cause disease and kill a wide range of other decapod crustacean hosts from temperate regions, including lobsters, crabs, crayfish and shrimp. For this reason, WSSV has recently been listed in European Community Council Directive 2006/88. Using principles laid down by the European Food Safety Authority (EFSA) we applied an array of diagnostic approaches to provide a definitive statement on the susceptibility to White Spot Syndrome Virus (WSSV) infection in seven ecologically or economically important crustacean species from Europe. We chose four marine species: Cancer pagurus, Homarus gammarus, Nephrops norvegicus and Carcinus maenas; one estuarine species, Eriocheir sinensis and two freshwater species, Austropotamobius pallipes and Pacifastacus leniusculus. Exposure trials based upon natural (feeding) and artificial (intra-muscular injection) routes of exposure to WSSV revealed universal susceptibility to WSSV infection in these hosts. However, the relative degree of susceptibility (measured by progression of infection to disease, and mortality) varied significantly between host species. In some instances (Type 1 hosts), pathogenesis mimicked that observed in penaeid shrimp hosts whereas in other examples (Types 2 and 3 hosts), infection did not readily progress to disease, even though hosts were considered as infected and susceptible according to accepted principles. Results arising from challenge studies are discussed in relation to the potential risk posed to non-target hosts by the inadvertent introduction of WSSV to European waters via trade. Furthermore, we highlight the potential for susceptible but relatively resistant hosts to serve as models to investigate natural mitigation strategies against WSSV in these hosts. We speculate that these non-model hosts may offer a unique insight into viral handling in crustaceans. PMID:22484233

  13. SIFamide peptides in clawed lobsters and freshwater crayfish (Crustacea, Decapoda, Astacidea): a combined molecular, mass spectrometric and electrophysiological investigation.

    PubMed

    Dickinson, Patsy S; Stemmler, Elizabeth A; Cashman, Christopher R; Brennan, Henry R; Dennison, Bobbi; Huber, Kristen E; Peguero, Braulio; Rabacal, Whitney; Goiney, Christopher C; Smith, Christine M; Towle, David W; Christie, Andrew E

    2008-04-01

    Recently, we identified the peptide VYRKPPFNGSIFamide (Val(1)-SIFamide) in the stomatogastric nervous system (STNS) of the American lobster Homarus americanus using matrix-assisted laser desorption/ionization-Fourier transform mass spectrometry (MALDI-FTMS). Given that H. americanus is the only species thus far shown to possess this peptide, and that a second SIFamide isoform, Gly(1)-SIFamide, is broadly conserved in other decapods, including another astacidean, the crayfish Procambarus clarkii, we became interested both in confirming our identification of Val(1)-SIFamide via molecular methods and in determining the extent to which this isoform is conserved within other members of the infraorder Astacidea. Here, we present the identification and characterization of an H. americanus prepro-SIFamide cDNA that encodes the Val(1) isoform. Moreover, we demonstrate via MALDI-FTMS the presence of Val(1)-SIFamide in a second Homarus species, Homarus gammarus. In contrast, only the Gly(1) isoform was detected in the other astacideans investigated, including the lobster Nephrops norvegicus, a member of the same family as Homarus, and the crayfish Cherax quadricarinatus, P. clarkii and Pacifastacus leniusculus, which represent members of each of the extant families of freshwater astacideans. These results suggest that Val(1)-SIFamide may be a genus (Homarus)-specific isoform. Interestingly, both Val(1)- and Gly(1)-SIFamide possess an internal dibasic site, Arg(3)-Lys(4), raising the possibility of the ubiquitously conserved isoform PPFNGSIFamide. However, this octapeptide was not detected via MALDI-FTMS in any of the investigated species, and when applied to the isolated STNS of H. americanus possessed little bioactivity relative to the full-length Val(1) isoform. Thus, it appears that the dodeca-variants Val(1)- and Gly(1)-SIFamide are the sole bioactive isoforms of this peptide family in clawed lobsters and freshwater crayfish. PMID:18308319

  14. Cloning and characterisation of a prophenoloxidase from the haemocytes of mud crab Scylla serrata.

    PubMed

    Ko, Chi-Fong; Chiou, Tzu-Ting; Vaseeharan, Baskaralingam; Lu, Jenn-Kan; Chen, Jiann-Chu

    2007-01-01

    A prophenoloxidase (proPO) cDNA was cloned from the haemocytes of mud crab Scylla serrata using oligonucleotide primers and RT-PCR. Both 3'- and 5'-regions were isolated by rapid amplification of cDNA end (RACE) method. Analysis of the nucleotide sequence revealed that the cDNA clone has a full length of 2663bp, with an open reading frame of 2019bp, a 124-bp 5'-untranslated region, and a 520-bp 3'-untranslated region containing a poly A signal. It encodes a protein of 673 amino acids with a predicted molecular weight of 77.5kDa and with an estimated pI of 5.96. It contains two putative tyrosinase copper-binding motifs with six histidine residues (copper A, 185, 189, 211, and copper B, 346, 350, 386). The proPO has thiol-ester-like motif (GCGWPQHM), which showed similar structural features of proPOs from other decapod crustaceans. It also contains five possible glycosylation sites, and a conserved C-terminal region common to all known proPOs. Sequence comparison showed that the proPO-deduced amino acid of mud crab S. serrata has an overall similarity of 78%, 57%, 56%, 51-55%, 54%, 53%, 52%, 52%, and 52% to that of Dungeness crab Cancer magister, American lobster Homarus americanus, European lobster Homarus gammarus, kuruma prawn Marsupenaeus japonicus, crayfish Pacifastacus leniusculus, white shrimp Litopenaeus vannamei, tiger shrimp Penaeus monodon, green tiger shrimp Penaeus semisulcatus, and giant freshwater prawn Macrobrachium rosenbergii, respectively. The proPO was strongly expressed in haemocytes, but not in heart, eyestalk, gill, muscle, ovary, hepatopancreas, stomach, and intestine. The proPO transcript of mud crab S. serrata increased significantly in 12 and 24h post-lipopolysaccharide (LPS) injection, but returned to the original values in 72h post injection. PMID:16806468

  15. Osmoregulation in the Hawaiian anchialine shrimp Halocaridina rubra (Crustacea: Atyidae): expression of ion transporters, mitochondria-rich cell proliferation and hemolymph osmolality during salinity transfers.

    PubMed

    Havird, Justin C; Santos, Scott R; Henry, Raymond P

    2014-07-01

    Studies of euryhaline crustaceans have identified conserved osmoregulatory adaptions allowing hyper-osmoregulation in dilute waters. However, previous studies have mainly examined decapod brachyurans with marine ancestries inhabiting estuaries or tidal creeks on a seasonal basis. Here, we describe osmoregulation in the atyid Halocaridina rubra, an endemic Hawaiian shrimp of freshwater ancestry from the islands' anchialine ecosystem (coastal ponds with subsurface freshwater and seawater connections) that encounters near-continuous spatial and temporal salinity changes. Given this, survival and osmoregulatory responses were examined over a wide salinity range. In the laboratory, H. rubra tolerated salinities of ~0-56‰, acting as both a hyper- and hypo-osmoregulator and maintaining a maximum osmotic gradient of ~868 mOsm kg(-1) H2O in freshwater. Furthermore, hemolymph osmolality was more stable during salinity transfers relative to other crustaceans. Silver nitrate and vital mitochondria-rich cell staining suggest all gills are osmoregulatory, with a large proportion of each individual gill functioning in ion transport (including when H. rubra acts as an osmoconformer in seawater). Additionally, expression of ion transporters and supporting enzymes that typically undergo upregulation during salinity transfer in osmoregulatory gills (i.e. Na(+)/K(+)-ATPase, carbonic anhydrase, Na(+)/K(+)/2Cl(-) cotransporter, V-type H(+)-ATPase and arginine kinase) were generally unaltered in H. rubra during similar transfers. These results suggest H. rubra (and possibly other anchialine species) maintains high, constitutive levels of gene expression and ion transport capability in the gills as a means of potentially coping with the fluctuating salinities that are encountered in anchialine habitats. Thus, anchialine taxa represent an interesting avenue for future physiological research. PMID:24744415

  16. Tissue distribution of 210Po and 210Pb in select marine species of the coast of Kudankulam, southern coast of Gulf of Mannar, India.

    PubMed

    Khan, Mohan Feroz; Wesley, Samuel Godwin

    2011-04-01

    Activities of 210Po and 210Pb in various tissues of four species of decapod crabs and two species of cephalopod mollusks (cuttlefishes) of Kudankulam coast were studied. A non-uniform distribution of these radionuclides was observed between the organs. Of all the tissues, 210Po and 210Pb were found accumulated more in the hepatopancreas and intestine of crabs and in the digestive gland, shell gland, and intestine of cephalopods. Among crabs, Charybdis lucifera registered a little higher 210Po and 210Pb activities. The cephalopod species Loligo duvauceli displayed higher 210Po and 210Pb in some organs when compared to Sepia pharaonis. The muscle of all the species registered lower activity. In cephalopods, the activity ratio of 210Po/210Pb fell within the range of 1-2 for most of the organs, and in crab tissues, it varied from 1.7 to 31.4. The biological concentration factor for organs of cephalopods ranged from 1.2×10(3) to 4.3×10(5) for 210Po and 4.8×10(2) to 8.4×10(4) for 210Pb and for organs of crabs it varied between 2.0×10(4) and 1.9×10(6) for 210Po and 9.2×10(2) and 2.4×10(4) for 210Pb. The study revealed that the organs associated with digestion and metabolism displayed a higher activity concentration than the other tissues. A significant variation in the accumulation of 210Po and 210Pb was noted between species (P<0.05). The activity levels recorded are in agreement with values recorded in related organisms in other parts of the world. The data generated will act as a reference database for these organisms of this coast in which a nuclear power station is under construction. PMID:20571883

  17. Spatial and temporal patterns in the hyperbenthic community structure in a warm temperate southern African permanently open estuary

    NASA Astrophysics Data System (ADS)

    Heyns, Elodie; Froneman, William

    2010-06-01

    The spatial and temporal patterns in the hyperbenthic community structure (>500 ?m) in the warm temperate, permanently open Kariega Estuary situated along the south-eastern coastline of South Africa was investigated monthly over a period of twelve months. Data were collected using a modified hyperbenthic sledge at six stations along the length of the estuary. Physico-chemical data indicate the presence of a constant reverse salinity gradient, with highest salinities measured in the upper reaches and lowest at the mouth of the estuary. Strong seasonal patterns in temperature, dissolved oxygen and total chlorophyll- a (chl- a) concentration were evident. Total average hyperbenthic densities ranged between 0.4 and 166 ind.m -3 in the lower net and between 0.2 and 225 ind.m -3 in the upper net. Hyperbenthic biomass values ranged between 0.02 and 11.9 mg.dry weight.m -3 in the lower net and between 0.02 and 17.4 mg.dry weight.m -3 in the upper net. Both the lower and upper nets were numerically dominated by decapods (mainly brachyuran crab zoea) with the exception of June and July 2008 when mysids (mainly Mesopodopsis wooldridgei) dominated, comprising up to 72.4 ± 58.14% of the total abundance in the lower net. A redundancy analysis (RDA) indicated that 99.2% of the variance in the hyperbenthic community structure could be explained by the first two canonical axes. Axis one, which accounted for 96.8% of the total variation detected in the ordination plot was highly correlated with sedimentary organic content and to a lesser extent the chl- a concentration within the Kariega Estuary. The correlations with the second canonical axis (2.4%) were less obvious, however, salinity and seston concentration were weakly correlated with this axis.

  18. Modifications to the bottomless lift net for sampling nekton in tidal mangrove forests

    USGS Publications Warehouse

    McIvor, C.C.; Silverman, N.L.

    2010-01-01

    Sampling fishes in vegetated intertidal wetlands is logistically challenging. We modified the 2 ?? 3-m2 bottomless lift net developed for sampling nekton (fish and decapod crustaceans) on the surface of salt marshes for use in tidal mangrove forests with a woody (as opposed to herbaceous) underground root system. As originally designed (Rozas, Mar Ecol Prog Ser 89:287-292, 1992), the lift net was buried directly in the marsh substrate. The net was raised at slack high tide thereby encircling nekton within the enclosed area. A chain-line on the net bottom prevented escape under the net once deployed. However, when we used this same design in tidal mangrove forests, the extensive woody roots and occasional slumping sediments resulted in uneven trenches that could not be cleared effectively during sample recovery. We made 3 modifications to the original net design: (i) lined the peat trenches with aluminum channels of uniform width and depth; (ii) replaced the previous chain-line with Velcro closures that directly attached the net to the inner face of the outer wall of the aluminum channel; and (iii) removed the subtidal pan previously used for concentrating the enclosed nekton at low tide, and filled in those depressions with on-site peat. In the modified version, the aluminum trench became the only subtidal refuge available to nekton, and it was from here that we collected the sample after the forest drained. These modifications permitted high clearing efficiency (93-100%) of fin-clipped individuals of two common species of estuarine resident fishes, Kryptolebias marmoratus (mangrove rivulus) and Bathygobius soporator (frillfin goby). Additionally, the density estimates of grass shrimp (Palaemonetes spp.) increased 10-fold post-modification. ?? 2010 US Government.

  19. Pharmacophore based approach to design inhibitors in crustaceans: an insight into the molt inhibition response to the receptor guanylyl cyclase.

    PubMed

    Shrivastava, Sajal; Princy, S Adline

    2014-04-01

    The first set of competitive inhibitors of molt inhibiting hormone (MIH) has been developed using the effective approaches such as Hip-Hop, virtual screening and manual alterations. Moreover, the conserved residues at 71 and 72 positions in the molt inhibiting hormone is known to be significant for selective inhibition of ecdysteroidogenesis; thus, the information from mutation and solution structure were used to generate common pharmacophore features. The geometry of the final six-feature pharmacophore was also found to be consistent with the homology-modeled MIH structures from various other decapod crustaceans. The Hypo-1, comprising six features hypothesis was carefully selected as a best pharmacophore model for virtual screening created on the basis of rank score and cluster processes. The hypothesis was validated and the database was virtually screened using this 3D query and the compounds were then manually altered to enhance the fit value. The hits obtained were further filtered for drug-likeness, which is expressed as physicochemical properties that contribute to favorable ADME/Tox profiles to eliminate the molecules exhibit toxicity and poor pharmacokinetics. In conclusion, the higher fit values of CI-1 (4.6), CI-4 (4.9) and CI-7 (4.2) in conjunction with better pharmacokinetic profile made these molecules practically helpful tool to increase production by accelerating molt in crustaceans. The use of feeding sub-therapeutic dosages of these growth enhancers can be very effectively implemented and certainly turn out to be a vital part of emerging nutritional strategies for economically important crustacean livestock. PMID:24772941

  20. Pre-partum diet of adult female bearded seals in years of contrasting ice conditions.

    PubMed

    Hindell, Mark A; Lydersen, Christian; Hop, Haakon; Kovacs, Kit M

    2012-01-01

    Changing patterns of sea-ice distribution and extent have measurable effects on polar marine systems. Beyond the obvious impacts of key-habitat loss, it is unclear how such changes will influence ice-associated marine mammals in part because of the logistical difficulties of studying foraging behaviour or other aspects of the ecology of large, mobile animals at sea during the polar winter. This study investigated the diet of pregnant bearded seals (Erignathus barbatus) during three spring breeding periods (2005, 2006 and 2007) with markedly contrasting ice conditions in Svalbard using stable isotopes (?(13)C and ?(15)N) measured in whiskers collected from their newborn pups. The ?(15)N values in the whiskers of individual seals ranged from 11.95 to 17.45 ‰, spanning almost 2 full trophic levels. Some seals were clearly dietary specialists, despite the species being characterised overall as a generalist predator. This may buffer bearded seal populations from the changes in prey distributions lower in the marine food web which seems to accompany continued changes in temperature and ice cover. Comparisons with isotopic signatures of known prey, suggested that benthic gastropods and decapods were the most common prey. Bayesian isotopic mixing models indicated that diet varied considerably among years. In the year with most fast-ice (2005), the seals had the greatest proportion of pelagic fish and lowest benthic invertebrate content, and during the year with the least ice (2006), the seals ate more benthic invertebrates and less pelagic fish. This suggests that the seals fed further offshore in years with greater ice cover, but moved in to the fjords when ice-cover was minimal, giving them access to different types of prey. Long-term trends of sea ice decline, earlier ice melt, and increased water temperatures in the Arctic are likely to have ecosystem-wide effects, including impacts on the forage bases of pagophilic seals. PMID:22693616

  1. Effects of Cadmium on Lipid Storage and Metabolism in the Freshwater Crab Sinopotamon henanense

    PubMed Central

    Yang, Jian; Liu, Dongmei; Jing, Weixin; Dahms, Hans-Uwe; Wang, Lan

    2013-01-01

    Since environmental effects of molecular traits are often questioned we analyze here the molecular effects of cadmium (Cd) on lipid pathways and their effects on tissues development. Lipids are an important energy source for the developing embryo, and accumulate in the ovary and hepatopancreas of decapod crustaceans. The extend of Cd affecting lipid storage and metabolism, is studied here with the freshwater crabs Sinopotamon henanense. Crabs were exposed to water-born Cd at 1.45, 2.9, 5.8 mg/l for 10, 15, and 20 days. With significantly increased Cd accumulation in exposed crabs, lipid content in hepatopancreas and ovary showed a time-dependent and concentration-dependent reduction, being at least one of the reasons for a lower ovarian index (OI) and hepatopancreatic index (HI). After 10-day exposure increased triglyceride (TG) level in hemolymph and up-regulation of pancreatic lipase (PL) activity in the hepatopancreas suggested an increased nutritional lipid uptake. However, two processes led to lower lipid levels upon Cd exposure: an increased utilization of lipids and a down-regulated lipoprotein lipase (LPL) led to insufficient lipid transport. 10-day Cd exposure also triggered the production of ?-nicotinamide adenine dinucleotide 2'-phosphate reduced tetrasodium salt hydrate (NADPH), as well as to the synthesis of adenosine triphosphate (ATP) and fatty acids. With increasing exposure time, the crabs at 15 and 20-day exposure contained less lipid and TG, suggesting that more energy was consumed during the exposure time. Meanwhile, the level of NADPH, ATP and the activity of PL, LPL, fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC) activity was down-regulated suggesting an impairment of the crab metabolism by Cd in addition to causing a lower lipid level. PMID:24130894

  2. Adult neurogenesis in the crayfish brain: proliferation, migration and possible origin of precursor cells

    PubMed Central

    Zhang, Y.; Allodi, S.; Sandeman, D.C.; Beltz, B.S.

    2015-01-01

    The birth of new neurons and their incorporation into functional circuits in the adult brain is a characteristic of many vertebrate and invertebrate organisms, including decapod crustaceans. Precursor cells maintaining life-long proliferation in the brains of crayfish (Procambarus clarkii, Cherax destructor) and clawed lobsters (Homarus americanus) reside within a specialized niche on the ventral surface of the brain; their daughters migrate to two proliferation zones along a stream formed by processes of the niche precursors. Here they divide again, finally producing interneurons in the olfactory pathway. The present studies in P. clarkii explore (1) differential proliferative activity among the niche precursor cells with growth and aging, (2) morphological characteristics of cells in the niche and migratory streams, and (3) aspects of the cell cycle in this lineage. Morphologically symmetrical divisions of neuronal precursor cells were observed in the niche near where the migratory streams emerge, as well as in the streams and proliferation zones. The nuclei of migrating cells elongate and undergo shape changes consistent with nucleokinetic movement. LIS1, a highly conserved dynein-binding protein, is expressed in cells in the migratory stream and neurogenic niche, implicating this protein in the translocation of crustacean brain neuronal precursor cells. Symmetrical divisions of the niche precursors and migration of both daughters raised the question of how the niche precursor pool is replenished. We present here preliminary evidence for an association between vascular cells and the niche precursors, which may relate to the life-long growth and maintenance of the crustacean neurogenic niche. PMID:19294644

  3. Molecular and morphological phylogeny of hooded shrimps, genera Betaeus and Betaeopsis (Decapoda, Alpheidae): testing the center of origin biogeographic model and evolution of life history traits.

    PubMed

    Anker, Arthur; Baeza, J Antonio

    2012-09-01

    The phylogenetic relationships of the alpheid shrimp genera Betaeus (Dana, 1852) (15 species) and Betaeopsis (Yaldwyn, 1971) (three species), collectively known as hooded shrimps, are analyzed with morphological, molecular (16S and H3) and combined "total evidence" (morphology+DNA) datasets. The tree topology resulting from morphological and combined analyses places Betaeus jucundus as sister to all the remaining species of Betaeus and Betaeopsis, rendering Betaeus paraphyletic. On the other hand, Betaeopsis is recovered as monophyletic. Betaeus australis is positioned as sister to the remaining species of Betaeus s. str. (excluding B. jucundus), which is composed of three well-supported and resolved clades. Mapping of biogeographic traits on the combined tree suggests at least two possible historic scenarios. In the first scenario, the North-East Pacific harboring the highest diversity of hooded shrimps (seven species of Betaeus), acted as the "center of origin", where species appeared, matured and eventually migrated toward peripheral regions. In the second scenario, Betaeus+Betaeopsis originated in the southern Indo-West Pacific and subsequently colonized the North-East Pacific, where a major radiation involving dispersal/vicariance events took place. The mapping of life history traits (symbiosis vs. free living and gregariousness vs. single/pair living) in the combined tree suggests (1) that different types of symbioses with dissimilar host organisms (sea urchins, abalones, other decapods, spoon worms) evolved independently more than once in the group (in B. jucundus and in various lineages of Betaeus s. str.), and (2) that gregariousness was ancestral in the Betaeus s. str. -Betaeopsis clade and later shifted toward single/pair living in several lineages. PMID:22579811

  4. Diversity and distribution of deep-sea shrimps in the Ross Sea region of Antarctica.

    PubMed

    Basher, Zeenatul; Bowden, David A; Costello, Mark J

    2014-01-01

    Although decapod crustaceans are widespread in the oceans, only Natantia (shrimps) are common in the Antarctic. Because remoteness, depth and ice cover restrict sampling in the South Ocean, species distribution modelling is a useful tool for evaluating distributions. We used physical specimen and towed camera data to describe the diversity and distribution of shrimps in the Ross Sea region of Antarctica. Eight shrimp species were recorded: Chorismus antarcticus; Notocrangon antarcticus; Nematocarcinus lanceopes; Dendrobranchiata; Pasiphaea scotiae; Pasiphaea cf. ledoyeri; Petalidium sp., and a new species of Lebbeus. For the two most common species, N. antarcticus and N. lanceopes, we used maximum entropy modelling, based on records of 60 specimens and over 1130 observations across 23 sites in depths from 269 m to 3433 m, to predict distributions in relation to environmental variables. Two independent sets of environmental data layers at 0.05° and 0.5° resolution respectively, showed how spatial resolution affected the model. Chorismus antarcticus and N. antarcticus were found only on the continental shelf and upper slopes, while N. lanceopes, Lebbeus n. sp., Dendrobranchiata, Petalidium sp., Pasiphaea cf. ledoyeri, and Pasiphaea scotiae were found on the slopes, seamounts and abyssal plain. The environmental variables that contributed most to models for N. antarcticus were depth, chlorophyll-a concentration, temperature, and salinity, and for N. lanceopes were depth, ice concentration, seabed slope/rugosity, and temperature. The relative ranking, but not the composition of these variables changed in models using different spatial resolutions, and the predicted extent of suitable habitat was smaller in models using the finer-scale environmental layers. Our modelling indicated that shrimps were widespread throughout the Ross Sea region and were thus likely to play important functional role in the ecosystem, and that the spatial resolution of data needs to be considered both in the use of species distribution models. PMID:25051333

  5. Spatial, temporal and ontogenetic variation in diet of anchovy ( Engraulis encrasicolus) on the Algerian coast (SW Mediterranean)

    NASA Astrophysics Data System (ADS)

    Bacha, M.; Amara, R.

    2009-11-01

    The diet of anchovy Engraulis encrasicolus was studied in three regions (Béjaia, Bénisaf and Ghazaouet) along the Algerian coast. Ontogenetic, spatial and seasonal variations in anchovy diet were investigated using multivariate analyses and analysed in relation with sea surface temperature and chlorophyll- a. 46 prey taxa of varying size between 0.57 mm ( Euterpina acutifrons) and 6.8 mm (fish larvae) were recorded. Whatever the season, the region or the fish size, anchovy is exclusively zooplanktivorous and copepods were the most present prey, constituting 87% by number of the prey taken and found in 98% of the anchovy stomachs examined. However, their occurrence and number varied according to the different areas, seasons and fish size. During its first year of life, anchovy feeds almost exclusively on copepods (mainly small and medium size prey). As anchovy grows, copepods are gradually substituted by large crustaceans such as decapods and amphipods. Hierarchical cluster analysis, analysis of similarities (ANOSIM) and similarities percentage (SIMPER) indicated a distinct diet of anchovy of the bay of Bejaia from those of the bays of Bénisaf and Ghazaouet probably due to differences in hydrologic conditions. Diet differences also occurred between seasons. Summer and spring have distinct prey assemblages each and showed low diet similarities with the two other seasons. More prey species were found in the diet during winter (36) and autumn (30) and the vacuity index was lower in winter. Temporal variability in satellite-derived chlorophyll- a matched the seasonal variability in the diversity of the anchovy prey and feeding intensity as reflected by the vacuity index, suggesting further investigation of the potential use of satellite-derived chlorophyll- a data as a proxy for anchovy feeding intensity.

  6. Morphology and histochemistry of the aesthetasc-associated epidermal glands in terrestrial hermit crabs of the genus Coenobita (Decapoda: Paguroidea).

    PubMed

    Tuchina, Oksana; Groh, Katrin C; Talarico, Giovanni; Müller, Carsten H G; Wielsch, Natalie; Hupfer, Yvonne; Svatoš, Aleš; Grosse-Wilde, Ewald; Hansson, Bill S

    2014-01-01

    Crustaceans have successfully adapted to a variety of environments including fresh- and saltwater as well as land. Transition from an aquatic to a terrestrial lifestyle required adaptations of the sensory equipment of an animal, particularly in olfaction, where the stimulus itself changes from hydrophilic to mainly hydrophobic, air-borne molecules. Hermit crabs Coenobita spp. (Anomura, Coenobitidae) have adapted to a fully terrestrial lifestyle as adults and have been shown to rely on olfaction in order to detect distant food items. We observed that the specialized olfactory sensilla in Coenobita, named aesthetascs, are immersed in a layer of mucous-like substance. We hypothesized that the mucous is produced by antennal glands and affects functioning of the aesthetascs. Using various microscopic and histochemical techniques we proved that the mucous is produced by aesthetasc-associated epidermal glands, which we consider to be modified rosette-type aesthetasc tegumental glands known from aquatic decapods. These epidermal glands in Coenobita are multicellular exocrine organs of the recto-canal type with tubulo-acinar arrangement of the secretory cells. Two distinct populations of secretory cells were clearly distinguishable with light and electron microscopy. At least part of the secretory cells contains specific enzymes, CUB-serine proteases, which are likely to be secreted on the surface of the aesthetasc pad and take part in antimicrobial defense. Proteomic analysis of the glandular tissue corroborates the idea that the secretions of the aesthetasc-associated epidermal glands are involved in immune responses. We propose that the mucous covering the aesthetascs in Coenobita takes part in antimicrobial defense and at the same time provides the moisture essential for odor perception in terrestrial hermit crabs. We conclude that the morphological modifications of the aesthetasc-associated epidermal glands as well as the functional characteristics of their secretions are important adaptations to a terrestrial lifestyle. PMID:24805352

  7. Application of D-Crustacean Hyperglycemic Hormone Induces Peptidases Transcription and Suppresses Glycolysis-Related Transcripts in the Hepatopancreas of the Crayfish Pontastacus leptodactylus - Results of a Transcriptomic Study.

    PubMed

    Manfrin, Chiara; Tom, Moshe; De Moro, Gianluca; Gerdol, Marco; Guarnaccia, Corrado; Mosco, Alessandro; Pallavicini, Alberto; Giulianini, Piero Giulio

    2013-01-01

    The crustacean Hyperglycemic Hormone (cHH) is a neuropeptide present in many decapods. Two different chiral isomers are simultaneously present in Astacid crayfish and their specific biological functions are still poorly understood. The present study is aimed at better understanding the potentially different effect of each of the isomers on the hepatopancreatic gene expression profile in the crayfish Pontastacus leptodactylus, in the context of short term hyperglycemia. Hence, two different chemically synthesized cHH enantiomers, containing either L- or D-Phe(3), were injected to the circulation of intermolt females following removal of their X organ-Sinus gland complex. The effects triggered by the injection of the two alternate isomers were detected after one hour through measurement of circulating glucose levels. Triggered changes of the transcriptome expression profile in the hepatopancreas were analyzed by RNA-seq. A whole transcriptome shotgun sequence assembly provided the assumedly complete transcriptome of P. leptodactylus hepatopancreas, followed by RNA-seq analysis of changes in the expression level of many genes caused by the application of each of the hormone isomers. Circulating glucose levels were much higher in response to the D-isoform than to the L-isoform injection, one hour from injection. Similarly, the RNA-seq analysis confirmed a stronger effect on gene expression following the administration of D-cHH, while just limited alterations were caused by the L-isomer. These findings demonstrated a more prominent short term effect of the D-cHH on the transcription profile and shed light on the effect of the D-isomer on specific functional gene groups. Another contribution of the study is the construction of a de novo assembly of the hepatopancreas transcriptome, consisting of 39,935 contigs, that dramatically increases the molecular information available for this species and for crustaceans in general, providing an efficient tool for studying gene expression patterns in this organ. PMID:23840318

  8. Characterization of a membrane-bound angiotensin-converting enzyme isoform in crayfish testis and evidence for its release into the seminal fluid.

    PubMed

    Simunic, Juraj; Soyez, Daniel; Kamech, Nédia

    2009-09-01

    In the present study, an isoform of angiotensin-converting enzyme was characterized from the testis of a decapod crustacean, the crayfish Astacus leptodactylus. Angiotensin-converting enzyme cDNA, obtained by 3'- to 5' RACE of testis RNAs, codes for a predicted one-domain protein similar to the mammalian germinal isoform of angiotensin-converting enzyme. All amino acid residues involved in enzyme activity are highly conserved, and a potential C-terminus transmembrane anchor may be predicted from the sequence. Comparison of this testicular isoform with angiotensin-converting enzyme from other crustaceans, namely Carcinus maenas, Homarus americanus (both reconstituted for this study from expressed-sequence tag data) and Daphnia pulex, suggests that membrane-bound angiotensin-converting enzyme occurs widely in crustaceans, conversely to other invertebrate groups where angiotensin-converting enzyme is predominantly a soluble protein. In situ hybridization and immunohistochemistry performed on testis sections show that angiotensin-converting enzyme mRNA is mainly localized in spermatogonias, whereas protein is present in spermatozoids. By contrast, in vas deferens, immunoreactivity is detected in the seminal fluid rather than in germ cells. Accordingly, angiotensin-converting enzyme activity assays of testis and vas deferens extracts demonstrate that the enzyme is present in the membrane fraction in testis, but in the soluble fraction in vas deferens. Taken together, the results obtained in the present study suggest that, during the migration of spermatozoids from testis to vas deferens, the enzyme is cleaved from the membrane of the germ cells and released into the seminal fluid. To our knowledge, this present study is the first to report such a maturation process for angiotensin-converting enzyme outside of mammals. PMID:19656189

  9. Nitric oxide production and sequestration in the sinus gland of the green shore crab Carcinus maenas.

    PubMed

    Pitts, Natalie L; Mykles, Donald L

    2015-02-01

    Molting in decapod crustaceans is regulated by molt-inhibiting hormone (MIH), a neuropeptide produced in the X-organ (XO)/sinus gland (SG) complex of the eyestalk ganglia (ESG). Pulsatile release of MIH from the SG suppresses ecdysteroidogenesis by the molting gland or Y-organ (YO). The hypothesis is that nitric oxide (NO), a neuromodulator that controls neurotransmitter release at presynaptic membranes, depresses the frequency and/or amount of MIH pulses to induce molting. NO synthase (NOS) mRNA was present in Carcinus maenas ESG and other tissues and NOS protein was present in the SG. A copper based ligand (CuFL), which reacts with NO to form a highly fluorescent product (NO-FL), was used to image NO in the ESG and SG and quantify the effects of NO scavenger (cPTIO), NOS inhibitor (l-NAME), and sodium azide (NaN3) on NO production in the SG. Pre-incubation with cPTIO prior to CuFL loading decreased NO-FL fluorescence ~30%; including l-NAME had no additional effect. Incubating SG with l-NAME during pre-incubation and loading decreased NO-FL fluorescence ~40%, indicating that over half of the NO release was not directly dependent on NOS activity. Azide, which reacts with NO-binding metal groups in proteins, reduced NO-FL fluorescence to near background levels without extensive cell death. Spectral shift analysis showed that azide displaced NO from a soluble protein in SG extract. These data suggest that the SG contains NO-binding protein(s) that sequester NO and releases it over a prolonged period. This NO release may modulate neuropeptide secretion from the axon termini in the SG. PMID:25452501

  10. Depth zonation and bathymetric trends of deep-sea megafaunal scavengers of the Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Yeh, John; Drazen, Jeffrey C.

    2009-02-01

    The deep sea has been shown to exhibit strong depth zonation in species composition and abundance. Examination of these patterns can offer ecological insight into how organisms adapt and respond to changing environmental parameters that co-occur with depth. Here we provide the first tropical study on bathymetric zonation and other depth-related trends (size, abundance, and species richness) spanning shelf to abyssal depths of scavenging megafauna. Baited time-lapse free-vehicle cameras were used to examine the deep-sea benthic and demersal scavenging communities of the Hawaiian Islands, an area for which the biology and ecology have remained poorly studied below 2000 m. Twenty-two deployments ranging in depth from 250 to 4783 m yielded 37 taxa attracted to bait, including the first known occurrence of the family Zoarcidae in the Hawaiian Islands. Cluster analysis of Bray-Curtis similarity of species peak abundance ( nmax) revealed four main faunal zones (250-500, 1000, 1500-3000, and ?4000 m) with significant separation (ANOSIM, global R=0.907, p=0.001) between designated depth groups. A major faunal break was identified at the 500-1000 m transition where species turnover was greatest, coinciding with the location of the local oxygen minimum zone. Dominance in species assemblage shifted from decapod crustaceans to teleosts moving from shallow to deeper faunal zones. Significant size differences in total length with depth were found for two of the four fish species examined. A logarithmic decline was observed in scavenger relative abundance with depth. Evidence of interaction between scavenging species was also noted between Synaphobranchus affinis and Neolithodes sp. (competition) and Histiobranchus sp. and aristeid shrimp (predation), suggesting that interactions between scavengers could influence indices of abundance generated from baited camera data.

  11. Isotopic composition of carbon and nitrogen of suprabenthic fauna in the NW Balearic Islands (western Mediterranean)

    NASA Astrophysics Data System (ADS)

    Madurell, T.; Fanelli, E.; Cartes, J. E.

    Stable isotope (? 13C and ? 15N) analyses were performed on suprabenthic fauna collected in the western Mediterranean (NW Balearic Islands), at depths ranging between 350 and 780 m. Samples were collected seasonally at bi-monthly intervals during six cruises performed between August 2003 and June 2004, using a Macer-GIROQ suprabenthic sledge (0.5 mm mesh size). Twenty-four separate species (5 mysids, 12 amphipods, 2 cumaceans, 2 isopods, 1 euphausiid, 1 decapod and 1 fish) and bulk copepods were analyzed on a seasonal basis for stable carbon and nitrogen isotopes. Stable nitrogen isotope ratios (? 15N) ranged from 2.3‰ (the amphipod Lepechinella manco in September 2003) to 13.0‰ (the amphipod Rhachotropis caeca in August 2003). ? 13C values ranged from - 24.2 (the cumacean Campylaspis sulcata in June 2004) to - 16.1 (the amphipod Bruzelia typica in November 2006). Both ? 13C and ? 15N values suggest that there are three trophic levels within the suprabenthic community. However, considering the bathymetric range of the species, the results suggest that the deepest assemblage supported only two trophic levels. The stable isotope ratios of suprabenthic fauna displayed a continuum of values and confirmed a wide spectrum of feeding types (from filter-feeders to predators). In general, and in spite of the poor knowledge about diets available for most suprabenthic species, higher ? 15N were found for carnivorous amphipods (e.g. Rhachotropis spp., Nicippe tumida) consuming copepods. Low overlap for ? 13C and ? 15N values was observed, though ? 15N values where less variable than ? 13C, which suggests high resource partitioning in this assemblage. Seasonal variations in isotopic composition for both ? 13C and ? 15N were low (less than 1‰ and 3‰, respectively) and variable depending on species. Low correlations between ? 13C and ? 15N of suprabenthic fauna were found for all periods studied, though increasing from February 2004 to June 2004 (after the main peak of primary production in surface). C:N ratio (indicator of lipid content) showed higher values in summer than in winter. This suggests that lipid content may explain the seasonal patterns of ? 13C variability and, due to the increase of storage products in phytoplankton and zooplankton, it possibly indicates the peak of primary production at the surface.

  12. Effect of hypoxia and anoxia on invertebrate behaviour: ecological perspectives from species to community level

    NASA Astrophysics Data System (ADS)

    Riedel, B.; Pados, T.; Pretterebner, K.; Schiemer, L.; Steckbauer, A.; Haselmair, A.; Zuschin, M.; Stachowitsch, M.

    2013-08-01

    Coastal hypoxia and anoxia have become a global key stressor to marine ecosystems, with almost 500 dead zones recorded wordwide. By triggering cascading effects from the individual organism to the community and ecosystem-level, oxygen depletions threat marine biodiversity and can alter ecosystem structure and function. By integrating both physiological function and ecological processes, animal behaviour is ideal for assessing the stress state of benthic macrofauna to low dissolved oxygen. The initial response of organisms can serve as an early-warning signal, while the successive behavioural reactions of key species indicate hypoxia levels and help assess community degradation. Here we document the behavioural responses of a representative spectrum of benthic macrofauna in the natural setting in the Northern Adriatic Sea, Mediterranean. We experimentally induced small-scale anoxia with a benthic chamber in 24 m depth to overcome the difficulties in predicting the onset of hypoxia, which often hinders full documentation in the field. The behavioural reactions were documented with a time-lapse camera. Oxygen depletion elicited significant and repeatable changes in general (visibility, locomotion, body movement and posture, location) and species-specific reactions in virtually all organisms (302 individuals from 32 species and 2 species groups). Most atypical (stress) behaviours were associated with specific oxygen thresholds: arm-tipping in the ophiuroid Ophiothrix quinquemaculata, for example, with the onset of mild hypoxia (< 2 mL O2 L-1), the emergence of polychates on the sediment surface with moderate hypoxia (< 1 mL O2 L-1), the emergence of the infaunal sea urchin Schizaster canaliferus on the sediment with severe hypoxia (< 0.5 mL O2 L-1) and heavy body rotations in sea anemones with anoxia. Other species changed their activity patterns, i.e. circadian rhythm in the hermit crab Paguristes eremita or the bioherm-associated crab Pisidia longimana. Intra- and interspecific reactions were weakened or changed: decapods ceased defensive and territorial behaviour, and predator-prey interactions and relationships shifted. This nuanced scale of resolution is a useful tool to interpret present benthic community status (behaviour) and past mortalities (community composition, e.g. survival of tolerant species). This information on the sensitivity (onset of stress response), tolerance (mortality, survival), and characteristics (i.e. life habit, functional role) of key species also helps predict potential future changes in benthic structure and ecosystem functioning. This integrated approach can transport complex ecological processes to the public and decision-makers and help define specific monitoring, assessment and conservation plans.

  13. The dynamics and scaling of force production during the tail-flip escape response of the California spiny lobster Panulirus interruptus.

    PubMed

    Nauen, J C; Shadwick, R E

    2001-05-01

    The tail-flip escape behavior is a stereotypical motor pattern of decapod crustaceans in which swift adduction of the tail to the thorax causes the animal to rotate, move vertically into the water column and accelerate rapidly backwards. Previous predictions that a strong jet force is produced during the flip as the tail adducts to the body are not supported by our simultaneous measurements of force production (using a transducer) and the kinematics (using high-speed video) of tail-flipping by the California spiny lobster Panulirus interruptus. Maximum force production occurred when the tail was positioned approximately normal to the body. Resultant force values dropped to approximately 15% of maximum during the last third of the flip and continued to decline as the tail closed against the body. In addition, maximum acceleration of the body of free-swimming animals occurs when the tail is positioned approximately normal to the body, and acceleration declines steadily to negative values as the tail continues to close. Thus, the tail appears to act largely as a paddle. Full flexion of the tail to the body probably increases the gliding distance by reducing drag and possibly by enhancing fluid circulation around the body. Morphological measurements indicate that Panulirus interruptus grows isometrically. However, measurements of tail-flip force production for individuals with a body mass (Mb) ranging from 69 to 412 g indicate that translational force scales as Mb0.83. This result suggests that force production scales at a rate greater than that predicted by the isometric scaling of muscle cross-sectional area (Mb2/3), which supports previously published data showing that the maximum accelerations of the tail and body of free-swimming animals are size-independent. Torque (tau) scaled as Mb1.29, which is similar to the hypothesized scaling relationship of Mb4/3. Given that tau is proportional to Mb1.29, one would predict rotational acceleration of the body (alpha) to decrease with increasing size as Mb(-0.37), which agrees with previously published kinematic data showing a decrease in alpha with increased Mb. PMID:11316502

  14. Analysis of neurotransmitter distribution in brain development of benthic and pelagic octopod cephalopods.

    PubMed

    Wollesen, Tim; Sukhsangchan, Charuay; Seixas, Pedro; Nabhitabhata, Jaruwat; Wanninger, Andreas

    2012-07-01

    The database on neurotransmitter distribution during central nervous system development of cephalopod mollusks is still scarce. We describe the ontogeny of serotonergic (5-HT-ir) and FMRFamide-like immunoreactive (Fa-lir) neurons in the central nervous system of the benthic Octopus vulgaris and Fa-lir distribution in the pelagic Argonauta hians. Comparing our data to previous studies, we aim at revealing shared immunochemical domains among coleoid cephalopods, i.e., all cephalopods except nautiluses. During development of O. vulgaris, 5-HT-ir and Fa-lir elements occur relatively late, namely during stage XII, when the brain neuropils are already highly differentiated. In stage XII-XX individuals, Fa-lir cell somata are located in the middle and posterior subesophageal mass and in the optic, posterior basal, and superior buccal lobes. 5-HT is predominately expressed in cell somata of the superior buccal, anterior basal, and optic lobes, as well as in the subesophageal mass. The overall population of Fa-lir neurons is larger than the one expressing 5-HT. Fa-lir elements are distributed throughout homologous brain areas of A. hians and O. vulgaris. We identified neuronal subsets with similar cell number and immunochemical phenotype in coleoids. These are located in corresponding brain regions of developmental stages and adults of O. vulgaris, A. hians, and the decapod squid Idiosepius notoides. O. vulgaris and I. notoides exhibit numerous 5-HT-ir cell somata in the superior buccal lobes but none or very few in the inferior buccal lobes. The latter have previously been homologized to the gastropod buccal ganglia, which also lack 5-HT-ir cell somata in euthyneuran gastropods. Among coleoids, 5-HT-ir neuronal subsets, which are located ventrally to the lateral anterior basal lobes and in the anterior middle subesophageal mass, are candidates for homologous subsets. Contrary to I. notoides, octopods exhibit Fa-lir cell somata ventrally to the brachial lobes and 5-HT-ir cell somata close to the stellate ganglia. PMID:22461086

  15. Replacement of an inherited stretch receptor by a newly evolved stretch receptor in hippid sand crabs.

    PubMed

    Paul, D H; Wilson, L J

    1994-12-01

    Primary sensory neurons that are motoneuron-like in morphology and often nonspiking (transmit afferent signals as graded depolarizations) characterize an unusual type of stretch receptor in decapod crustaceans. Nonspiking and spiking receptors occur in similar positions at homologous joints in different species and have been presumed to be homologous, the spiking one considered "primitive". To better understand the evolutionary origin of these stretch receptors and why some are nonspiking, we examined the spiking telson-uropod stretch receptors in the spiny sand crab Blepharipoda occidentalis (Albuneidae) and the squat lobster Munida quadrispina (Galatheidae) and compared them with the nonspking telson-uropod stretch receptor of the mole sand crab Emerita analoga (Hippidae). The position, morphology and responses to stretch of the sensory neurons, and the ultrastructure of the elastic strand portion of the receptor are similar in M. quadrispina and B. occidentalis, except that in B. occidentalis the receptor muscles are substantially smaller and the extracellular matrix of the elastic receptor strand is both more extensive and more organized, reminiscent of the ultrastructure of E. analoga's nonspiking receptor. We conclude that the spiking telson-uropod stretch receptors of albuneids and galatheids are homologous. The differences in the ultrastructure of their receptor strands imply that the efficiency of coupling receptor length change to deformation of the dendritic termini increases in the order M. quadrispina < B. occidentalis < E. analoga. The spiking and nonspiking telson-uropod stretch receptors differ anatomically in three major respects that appear to preclude their homology. (1) The receptor strands are on opposite sides of a conserved muscle. (2) The sensory somata are in different regions of the sixth abdominal ganglion: a lateral cluster of somata for the spiking sensory neurons and two medial clusters, one anterior, one posterior, for the nonspiking sensory neurons. (3) The neuropil projections of the sensory neurons are different. We conclude that the hippid's nonspiking telson-uropod stretch receptor evolved de novo and not by modification of the ancestral anomuran telson-uropod stretch receptor (which Hippidae have lost). PMID:7860798

  16. Transcriptome Analysis of Androgenic Gland for Discovery of Novel Genes from the Oriental River Prawn, Macrobrachium nipponense, Using Illumina Hiseq 2000

    PubMed Central

    Jin, Shubo; Fu, Hongtuo; Zhou, Qiao; Sun, Shengming; Jiang, Sufei; Xiong, Yiwei; Gong, Yongsheng; Qiao, Hui; Zhang, Wenyi

    2013-01-01

    Background The oriental river prawn, Macrobrachium nipponense, is an important aquaculture species in China, even in whole of Asia. The androgenic gland produces hormones that play crucial roles in sexual differentiation to maleness. This study is the first de novo M. nipponense transcriptome analysis using cDNA prepared from mRNA isolated from the androgenic gland. Illumina/Solexa was used for sequencing. Methodology and Principal Finding The total volume of RNA sample was more than 5 ug. We generated 70,853,361 high quality reads after eliminating adapter sequences and filtering out low-quality reads. A total of 78,408 isosequences were obtained by clustering and assembly of the clean reads, producing 57,619 non-redundant transcripts with an average length of 1244.19 bp. In total 70,702 isosequences were matched to the Nr database, additional analyses were performed by GO (33,203), KEGG (17,868), and COG analyses (13,817), identifying the potential genes and their functions. A total of 47 sex-determination related gene families were identified from the M. nipponense androgenic gland transcriptome based on the functional annotation of non-redundant transcripts and comparisons with the published literature. Furthermore, a total of 40 candidate novel genes were found, that may contribute to sex-determination based on their extremely high expression levels in the androgenic compared to other sex glands,. Further, 437 SSRs and 65,535 high-confidence SNPs were identified in this EST dataset from which 14 EST-SSR markers have been isolated. Conclusion Our study provides new sequence information for M. nipponense, which will be the basis for further genetic studies on decapods crustaceans. More importantly, this study dramatically improves understanding of sex-determination mechanisms, and advances sex-determination research in all crustacean species. The huge number of potential SSR and SNP markers isolated from the transcriptome may shed the lights on research in many fields, including the evolution and molecular ecology of Macrobrachium species. PMID:24204682

  17. Diet shifts of Caribbean grunts (Haemulidae) and snappers (Lutjanidae) and the relation with nursery-to-coral reef migrations

    NASA Astrophysics Data System (ADS)

    Cocheret de la Moriničre, E.; Pollux, B. J. A.; Nagelkerken, I.; van der Velde, G.

    2003-08-01

    The spatial size distribution of grunts and snappers have previously indicated the separation of juveniles in nursery habitats from the adults on the coral reef. This implies life cycle migrations from nursery habitats (such as seagrass beds and mangroves) to the coral reef. If diet shifts are related to such migrations, then the diets of these fish must change before or around the fish size at which such migrations take place. A wide size range of juveniles of two grunt species ( Haemulon sciurus and Haemulon flavolineatum) and of two snapper species ( Lutjanus apodus and Ocyurus chrysurus) were caught in seagrass beds and mangroves, and their gut contents identified and quantified. Regression analysis between fish size and dietary importance of small crustaceans showed a negative relationship in all four species. Positive relations were found for H. sciurus, L. apodus and O. chrysurus between fish length and the dietary importance of decapods, and for L. apodusand O. chrysurus between fish length and prey fish importance. Critical changes in the fish diets with fish size were examined by application of a Canonical Correspondence Analysis (CCA). The CCA yielded three clusters of size-classes of fishes with similar diets, and application of a Mantel test showed that each of these clusters had significantly different diets, and that each cluster diet was significantly specialised. The size at which a fish species 'switched' from one cluster to another was compared with size-at-maturity data and with the typical size at which these species migrate from the nursery habitats to the coral reef. H. sciurus and H. flavolineatum may be prompted to migrate from the nursery habitats to coral reef habitats because of dietary changes, or because of the development of the gonads. For L. apodus and O. chrysurus, a dietary changeover forms a more likely explanation for nursery-to-reef migrations than does sexual maturation because these species reach maturity at sizes much larger than the maximum size of individuals found in nursery habitats. Although other factors may theoretically initiate or promote the migration patterns, the results of this study indicate that ontogenetic dietary changes may crucially influence the nursery-to-coral reef migrations of these reef fish species.

  18. Food utilisation by coastal fish assemblages in rocky and soft bottoms on the Swedish west coast: Inference for identification of essential fish habitats

    NASA Astrophysics Data System (ADS)

    Stĺl, Johan; Pihl, Leif; Wennhage, Hĺkan

    2007-02-01

    The concept of essential fish habitats (EFHs) is widely accepted for conservational and management purposes. EFHs are often considered as high quality habitats for fisheries species and subsequently of high values for society. In this study, fish and Substrate-Associated Prey (SAP) were sampled during the productive summer season 1998 (fish) and 2003 and 2004 (SAP) in shallow coastal rocky- and soft-bottom habitats on the Swedish west coast. The aim was to study the spatial and monthly variation of SAP as well as abundance and biomass of fish, and to examine if food items found in the diet of the fish assemblage were derived from SAP. We also examined if the diet of Ctenolabrus rupestris, a resident and abundant fish species in the shallow coastal habitats, and the diet of four seasonally abundant and commercially important fish species ( Gadus morhua, Pleuronectes platessa, Salmo trutta and Scomber scombrus) were derived from SAP. There were significantly higher mean species number and abundance of the SAP assemblage on rocky compared to soft bottoms and the highest values were found on the rocky bottoms in August and in the shallowest (0-3 m) depth strata. There were no significant differences in number of fish species caught in the two habitats, although mean number of fish and mean biomass were significantly higher on rocky bottoms. Both habitats showed the same seasonal variation and the highest values of number of fish species, abundance and biomass were observed in June. On rocky bottoms, gastropods and amphipods were the most frequent food items in the diet of the entire fish assemblage and these items were also the most abundant SAP in this habitat. The dominant food items of the soft-bottom fish assemblage were decapods and fish, which were not common SAP. However, except for S. scombrus, the diet of the selected fish species showed a strong association to the SAP availability. Gadus morhua displayed the strongest association to SAP on rocky bottoms and P. platessa and C. rupestris to SAP on soft bottoms. Further, for C. rupestris, multivariate statistical analysis showed a significant association to the SAP assemblage on both rocky and soft bottoms. These results provide vital new information for the management and conservation of Essential Fish Habitats on the Swedish west coast.

  19. Large-field-of-view wide-spectrum artificial reflecting superposition compound eyes

    NASA Astrophysics Data System (ADS)

    Huang, Chi-Chieh

    The study of the imaging principles of natural compound eyes has become an active area of research and has fueled the advancement of modern optics with many attractive design features beyond those available with conventional technologies. Most prominent among all compound eyes is the reflecting superposition compound eyes (RSCEs) found in some decapods. They are extraordinary imaging systems with numerous optical features such as minimum chromatic aberration, wide-angle field of view (FOV), high sensitivity to light and superb acuity to motion. Inspired by their remarkable visual system, we were able to implement the unique lens-free, reflection-based imaging mechanisms into a miniaturized, large-FOV optical imaging device operating at the wide visible spectrum to minimize chromatic aberration without any additional post-image processing. First, two micro-transfer printing methods, a multiple and a shear-assisted transfer printing technique, were studied and discussed to realize life-sized artificial RSCEs. The processes exploited the differential adhesive tendencies of the microstructures formed between a donor and a transfer substrate to accomplish an efficient release and transfer process. These techniques enabled conformal wrapping of three-dimensional (3-D) microstructures, initially fabricated in two-dimensional (2-D) layouts with standard fabrication technology onto a wide range of surfaces with complex and curvilinear shapes. Final part of this dissertation was focused on implementing the key operational features of the natural RSCEs into large-FOV, wide-spectrum artificial RSCEs as an optical imaging device suitable for the wide visible spectrum. Our devices can form real, clear images based on reflection rather than refraction, hence avoiding chromatic aberration due to dispersion by the optical materials. Compared to the performance of conventional refractive lenses of comparable size, our devices demonstrated minimum chromatic aberration, exceptional FOV up to 165o without distortion, modest spherical aberrations and comparable imaging quality without any post-image processing. Together with an augmenting cruciform pattern surrounding each focused image, our devices possessed enhanced, dynamic motion-tracking capability ideal for diverse applications in military, security, search and rescue, night navigation, medical imaging and astronomy. In the future, due to its reflection-based operating principles, it can be further extended into mid- and far-infrared for more demanding applications.

  20. Characterization of the putative farnesoic acid O-methyltransferase (LvFAMeT) cDNA from white shrimp, Litopenaeus vannamei: Evidence for its role in molting.

    PubMed

    Hui, Jerome Ho Lam; Tobe, Stephen S; Chan, Siu-Ming

    2008-02-01

    Methyl farnesoate (MF) is the crustacean homolog of the insect juvenile hormone and is believed to regulate growth and reproduction in crustaceans. Farnesoic acid O-methyltransferase (FAMeT) catalyzes the conversion of farnesoic acid (FA) to MF. Here we report the cloning and characterization of two forms of FAMeTs (i.e. LvFAMeT-S and LvFAMeT-L) from the shrimp Litopenaeus vannamei. LvFAMeT transcript has a wide tissue distribution pattern in L. vannamei and is also expressed in nauplius, zoea, mysis, post-larval stages and adults. Unlike FAMeTs reported in other decapods, transcripts of two different sizes were detected in L. vannamei. We postulate that the wide distribution of LvFAMeT expression may be related to its role in growth and regulation of molting. To study the functions of LvFAMeT in molting, the RNA interference (RNAi) technique was used. Injection of double stranded RNA (dsRNA) for LvFAMeT knocked down the expression of LvFAMeT in shrimp for at least 3 days and the shrimp did not advance to the final stage of molt cycle. Furthermore, the expression of the molt-related genes encoding cathepsin-L and the hemocyanin gene was disturbed. Subsequently, 100% mortality of the shrimp was observed in the LvFAMeT dsRNA-injected shrimp. In contrast, control shrimp completed their molt and proceeded to the next molt cycle. We postulate that, as an important enzyme for the conversion of FA to MF, RNAi injection knocked down the expression of LvFAMeT which could potentially result in a decrease in the production of MF and subsequently, could affect the molting process. The newly identified LvFAMeT may be involved in the control of molting in shrimp. The results of this study demonstrate the potential use of the RNA interference technique to study other putative genes identified in crustaceans. PMID:18226425

  1. Automated image analysis for the detection of benthic crustaceans and bacterial mat coverage using the VENUS undersea cabled network.

    PubMed

    Aguzzi, Jacopo; Costa, Corrado; Robert, Katleen; Matabos, Marjolaine; Antonucci, Francesca; Juniper, S Kim; Menesatti, Paolo

    2011-01-01

    The development and deployment of sensors for undersea cabled observatories is presently biased toward the measurement of habitat variables, while sensor technologies for biological community characterization through species identification and individual counting are less common. The VENUS cabled multisensory network (Vancouver Island, Canada) deploys seafloor camera systems at several sites. Our objective in this study was to implement new automated image analysis protocols for the recognition and counting of benthic decapods (i.e., the galatheid squat lobster, Munida quadrispina), as well as for the evaluation of changes in bacterial mat coverage (i.e., Beggiatoa spp.), using a camera deployed in Saanich Inlet (103 m depth). For the counting of Munida we remotely acquired 100 digital photos at hourly intervals from 2 to 6 December 2009. In the case of bacterial mat coverage estimation, images were taken from 2 to 8 December 2009 at the same time frequency. The automated image analysis protocols for both study cases were created in MatLab 7.1. Automation for Munida counting incorporated the combination of both filtering and background correction (Median- and Top-Hat Filters) with Euclidean Distances (ED) on Red-Green-Blue (RGB) channels. The Scale-Invariant Feature Transform (SIFT) features and Fourier Descriptors (FD) of tracked objects were then extracted. Animal classifications were carried out with the tools of morphometric multivariate statistic (i.e., Partial Least Square Discriminant Analysis; PLSDA) on Mean RGB (RGBv) value for each object and Fourier Descriptors (RGBv+FD) matrices plus SIFT and ED. The SIFT approach returned the better results. Higher percentages of images were correctly classified and lower misclassification errors (an animal is present but not detected) occurred. In contrast, RGBv+FD and ED resulted in a high incidence of records being generated for non-present animals. Bacterial mat coverage was estimated in terms of Percent Coverage and Fractal Dimension. A constant Region of Interest (ROI) was defined and background extraction by a Gaussian Blurring Filter was performed. Image subtraction within ROI was followed by the sum of the RGB channels matrices. Percent Coverage was calculated on the resulting image. Fractal Dimension was estimated using the box-counting method. The images were then resized to a dimension in pixels equal to a power of 2, allowing subdivision into sub-multiple quadrants. In comparisons of manual and automated Percent Coverage and Fractal Dimension estimates, the former showed an overestimation tendency for both parameters. The primary limitations on the automatic analysis of benthic images were habitat variations in sediment texture and water column turbidity. The application of filters for background corrections is a required preliminary step for the efficient recognition of animals and bacterial mat patches. PMID:22346657

  2. Metabarcoding dietary analysis of coral dwelling predatory fish demonstrates the minor contribution of coral mutualists to their highly partitioned, generalist diet

    PubMed Central

    Meyer, Christopher P.; Mills, Suzanne C.

    2015-01-01

    Understanding the role of predators in food webs can be challenging in highly diverse predator/prey systems composed of small cryptic species. DNA based dietary analysis can supplement predator removal experiments and provide high resolution for prey identification. Here we use a metabarcoding approach to provide initial insights into the diet and functional role of coral-dwelling predatory fish feeding on small invertebrates. Fish were collected in Moorea (French Polynesia) where the BIOCODE project has generated DNA barcodes for numerous coral associated invertebrate species. Pyrosequencing data revealed a total of 292 Operational Taxonomic Units (OTU) in the gut contents of the arc-eye hawkfish (Paracirrhites arcatus), the flame hawkfish (Neocirrhites armatus) and the coral croucher (Caracanthus maculatus). One hundred forty-nine (51%) of them had species-level matches in reference libraries (>98% similarity) while 76 additional OTUs (26%) could be identified to higher taxonomic levels. Decapods that have a mutualistic relationship with Pocillopora and are typically dominant among coral branches, represent a minor contribution of the predators’ diets. Instead, predators mainly consumed transient species including pelagic taxa such as copepods, chaetognaths and siphonophores suggesting non random feeding behavior. We also identified prey species known to have direct negative interactions with stony corals, such as Hapalocarcinus sp, a gall crab considered a coral parasite, as well as species of vermetid snails known for their deleterious effects on coral growth. Pocillopora DNA accounted for 20.8% and 20.1% of total number of sequences in the guts of the flame hawkfish and coral croucher but it was not detected in the guts of the arc-eye hawkfish. Comparison of diets among the three fishes demonstrates remarkable partitioning with nearly 80% of prey items consumed by only one predator. Overall, the taxonomic resolution provided by the metabarcoding approach highlights a highly complex interaction web and demonstrates that levels of trophic partitioning among coral reef fishes have likely been underestimated. Therefore, we strongly encourage further empirical approaches to dietary studies prior to making assumptions of trophic equivalency in food web reconstruction. PMID:26137428

  3. Metabarcoding dietary analysis of coral dwelling predatory fish demonstrates the minor contribution of coral mutualists to their highly partitioned, generalist diet.

    PubMed

    Leray, Matthieu; Meyer, Christopher P; Mills, Suzanne C

    2015-01-01

    Understanding the role of predators in food webs can be challenging in highly diverse predator/prey systems composed of small cryptic species. DNA based dietary analysis can supplement predator removal experiments and provide high resolution for prey identification. Here we use a metabarcoding approach to provide initial insights into the diet and functional role of coral-dwelling predatory fish feeding on small invertebrates. Fish were collected in Moorea (French Polynesia) where the BIOCODE project has generated DNA barcodes for numerous coral associated invertebrate species. Pyrosequencing data revealed a total of 292 Operational Taxonomic Units (OTU) in the gut contents of the arc-eye hawkfish (Paracirrhites arcatus), the flame hawkfish (Neocirrhites armatus) and the coral croucher (Caracanthus maculatus). One hundred forty-nine (51%) of them had species-level matches in reference libraries (>98% similarity) while 76 additional OTUs (26%) could be identified to higher taxonomic levels. Decapods that have a mutualistic relationship with Pocillopora and are typically dominant among coral branches, represent a minor contribution of the predators' diets. Instead, predators mainly consumed transient species including pelagic taxa such as copepods, chaetognaths and siphonophores suggesting non random feeding behavior. We also identified prey species known to have direct negative interactions with stony corals, such as Hapalocarcinus sp, a gall crab considered a coral parasite, as well as species of vermetid snails known for their deleterious effects on coral growth. Pocillopora DNA accounted for 20.8% and 20.1% of total number of sequences in the guts of the flame hawkfish and coral croucher but it was not detected in the guts of the arc-eye hawkfish. Comparison of diets among the three fishes demonstrates remarkable partitioning with nearly 80% of prey items consumed by only one predator. Overall, the taxonomic resolution provided by the metabarcoding approach highlights a highly complex interaction web and demonstrates that levels of trophic partitioning among coral reef fishes have likely been underestimated. Therefore, we strongly encourage further empirical approaches to dietary studies prior to making assumptions of trophic equivalency in food web reconstruction. PMID:26137428

  4. Structure and dynamics of food webs in the water column on shelf and slope grounds of the western Mediterranean

    NASA Astrophysics Data System (ADS)

    Valls, M.; Sweeting, C. J.; Olivar, M. P.; Fernández de Puelles, M. L.; Pasqual, C.; Polunin, N. V. C.; Quetglas, A.

    2014-10-01

    Benthic-pelagic coupling is an important process connecting species throughout the water column, particularly, in deep-sea systems where faunal assemblages can be dense if indirectly sustained by production from the above. Through stable isotope analyses, this study explored the sources of production, trophic structure, and bentho-pelagic coupling in two locations with contrasting oceanographic conditions from the western Mediterranean, in the Balearic (BsB) and the Algerian (AsB) sub-basins. The samples of 89 dominant species (23 decapods, 19 cephalopods, 33 fishes, among the other taxa), inhabiting the hyperbenthic and pelagic domains, from the shelf break (250 m), upper slope (650 m), and middle slope (850 m) were analyzed. Results suggested long food webs of approximately four trophic levels (TrLs) that were sustained by planktonic source material in shallower waters and degraded particulate organic matter of planktonic origin in deeper waters. Most of the collected species (70%) occupied intermediate trophic positions between the 3rd and 4th TrLs. The species ?15N and ?13C values exhibited a broad range, consistent with the high diversity that might be attributed to the oligotrophic conditions. As the depth increased, stronger segregation occurred between the trophic groups, and spatial differences were found among consumers of the two locations. Species in the AsB always had consistently higher ?15N values than in the BsB, which could possibly be attributed to the basal ?15N that was present through the food web. Despite the contrasting basin characteristics, a similarly close bentho-pelagic coupling pattern was observed at both locations, except at the deepest ground, especially at the AsB, where the mean ?13C values from the hyperbenthic and pelagic compartments were more distant. This could be related to the higher degree of reworking of organic matter in the AsB. Overall, these findings suggested the need for a depth-stratified approach to analyze deep-sea food webs in the study site in future studies.

  5. Mercury bioaccumulation in cartilaginous fishes from Southern New England coastal waters: contamination from a trophic ecology and human health perspective.

    PubMed

    Taylor, David L; Kutil, Nicholas J; Malek, Anna J; Collie, Jeremy S

    2014-08-01

    This study examined total mercury (Hg) concentrations in cartilaginous fishes from Southern New England coastal waters, including smooth dogfish (Mustelus canis), spiny dogfish (Squalus acanthias), little skate (Leucoraja erinacea), and winter skate (Leucoraja ocellata). Total Hg in dogfish and skates were positively related to their respective body size and age, indicating Hg bioaccumulation in muscle tissue. There were also significant inter-species differences in Hg levels (mean ± 1 SD, mg Hg/kg dry weight, ppm): smooth dogfish (3.3 ± 2.1 ppm; n = 54) > spiny dogfish (1.1 ± 0.7 ppm; n = 124) > little skate (0.4 ± 0.3 ppm; n = 173) ? winter skate (0.3 ± 0.2 ppm; n = 148). The increased Hg content of smooth dogfish was attributed to its upper trophic level status, determined by stable nitrogen (?(15)N) isotope analysis (mean ?(15)N = 13.2 ± 0.7‰), and the consumption of high Hg prey, most notably cancer crabs (0.10 ppm). Spiny dogfish had depleted ?(15)N signatures (11.6 ± 0.8‰), yet demonstrated a moderate level of contamination by foraging on pelagic prey with a range of Hg concentrations, e.g., in order of dietary importance, butterfish (Hg = 0.06 ppm), longfin squid (0.17 ppm), and scup (0.11 ppm). Skates were low trophic level consumers (?(15)N = 11.9-12.0‰) and fed mainly on amphipods, small decapods, and polychaetes with low Hg concentrations (0.05-0.09 ppm). Intra-specific Hg concentrations were directly related to ?(15)N and carbon (?(13)C) isotope signatures, suggesting that Hg biomagnifies across successive trophic levels and foraging in the benthic trophic pathway increases Hg exposure. From a human health perspective, 87% of smooth dogfish, 32% of spiny dogfish, and <2% of skates had Hg concentrations exceeding the US Environmental Protection Agency threshold level (0.3 ppm wet weight). These results indicate that frequent consumption of smooth dogfish and spiny dogfish may adversely affect human health, whereas skates present minimal risk. PMID:25081850

  6. Low faunal diversity on Maltese sandy beaches: fact or artefact?

    NASA Astrophysics Data System (ADS)

    Deidun, Alan; Azzopardi, Marthese; Saliba, Stephen; Schembri, Patrick J.

    2003-10-01

    Eight sandy beaches on Malta and two on Gozo were sampled for macrofauna to test the hypothesis that Maltese beaches have an intrinsically low diversity. Stations distributed in the supralittoral (dry zone), mediolittoral (wet zone) and upper infralittoral (submerged zone to 1 m water depth) were sampled by sieving core samples and standardised searching during daytime, and pitfall trapping and standardised sweeping of the water column using a hand-net at night, as appropriate. Physical parameters of the sediment were measured and human occupancy of the beaches was estimated. From the supralittoral and mediolittoral, 39 species represented by 1584 individuals were collected by the combined techniques of pitfall trapping, sieving and standard searching. For Ramla beach, which had the highest diversity, 267 individuals representing 25 infaunal species were collected by sieving from a combined volume of 1.175 m 3 of sand, and 149 individuals representing 28 epifaunal species were collected by standardised searching from a combined area of 700 m 2 of sand during two winter and two summer sampling sessions between 1992 and 1993. For nine other beaches sampled during the summer of 2000, only six macrofaunal species were collected from core samples, with overall population densities ranging from 4.13 to 45.45 individuals m -2. Only 92 individuals belonging to 12 species were collected by hand-net from the uppermost infralittoral of five beaches sampled using this method during the summer of 2000. Taxa of gastropods, bivalves, decapods, mysids and staphylinid beetles generally abundant on Mediterranean sandy beaches, were entirely absent from the beaches sampled. Few correlations that could explain the impoverishment of Maltese sandy beaches were found between physical parameters and faunal abundances, and other factors such as inadequate sampling effort, human disturbance and marine pollution were also excluded; however, seasonally biased sampling may partly explain the results obtained. One factor that may explain why certain species are missing could be lack of recruitment, due to Malta's geographical isolation from the European and African mainlands.

  7. Climatic changes in hydrological and biological characteristics of the North-Western Black Sea region

    NASA Astrophysics Data System (ADS)

    Kovalyshyna, S.; Ivanov, S.; Matygin, A.

    2009-04-01

    The last decades have shown considerable climatic changes in all components of the Earth System. In particular, a hydrological regime of river runoffs in the North-Western Black Sea (NWBS) shows changes on seasonal and interannual scales. A general reduction in annual runoff occurs, while winter flow increases and spring flow decreases. This can be explained by the fact that the snow cover becomes less important with regional warming. Changes in the hydrological regime affect the vertical thermohaline structure and circulation in the NWBS. Observations in coastal waters show that both the temperature and salinity changed remarkably for the winter, while there are no significant variations for the summer season. Moreover, for the winter season, temperature has increased by about 2?C within the upper layer of 0-10 m and more than 3?C in the benthonic layer. Changes of salinity in the upper and benthonic layers are of opposite signs leading to weakening of the vertical water exchange between two layers. The changes in hydrological environment lead to consequent changes of diversity and population of hydrobiota. Biological components are less sensitive to the interannual changes and work like a natural filter smoothing this temporal scale and emphasizing longer fluctuations. Due to the warming, the spring peak of phytoplankton has moved from May to late March - early April and its population during the last decade considerably increased. The major contribution of this growth is associated with the green and blue-green seaweed microalgae, coming into the NWBS with river runoff. The increasing amount of microalgae while decreasing the biomass means the degradation of macrocells species of microalgae. The peaks of population and biomass of zooplankton follow in 2-4 weeks after microalgae, which is the forage reserve. Diversity and amount of zooplankton have been degradated in the past decades. The spring peak associated with the zooplankton has especially decreased during last decade. Some species of decapods larvae disappeared totally. Thus, the basic signature of destabilization in hydrobiology environment during climate changes is the reduction of diversity in favour of simplest species and the increase of seasonal amplitude of their population.

  8. Climate-dependent evolution of Antarctic ectotherms: An integrative analysis

    NASA Astrophysics Data System (ADS)

    Pörtner, Hans O.

    2006-04-01

    The paper explores the climate-dependent evolution of marine Antarctic fauna and tries to identify key mechanisms involved as well as the driving forces that have caused the physiological and life history characteristics observed today. In an integrative approach it uses the recent concept of oxygen and capacity limited thermal tolerance to identify potential links between molecular, cellular, whole-organism, and ecological characteristics of marine animal life in the Antarctic. As a generalized pattern, minimization of baseline energy costs, for the sake of maximized growth in the cold, appears as one over-arching principle shaping the evolution and functioning of Antarctic marine ectotherms. This conclusion is supported by recent comparisons with (sub-) Arctic ectotherms, where elevated levels of energy turnover result at unstable, including cold temperatures, and are related to wide windows of thermal tolerance and associated metabolic features. At biochemical levels, metabolic regulation at low temperatures in general, is supported by the cold compensation of enzyme kinetic parameters like substrate affinities and turnover numbers, through minute structural modifications of the enzyme molecule. These involve a shift in protein folding, sometimes supported by the replacement of individual amino acids. The hypothesis is developed that efficient metabolic regulation at low rates in Antarctic marine stenotherms occurs through high mitochondrial densities at low capacities and possibly enhanced levels of Arrhenius activation energies or activation enthalpies. This contrasts the more costly patterns of metabolic regulation at elevated rates in cold-adapted eurytherms. Energy savings in Antarctic ectotherms, largely exemplified in fish, typically involve low-cost, diffusive oxygen distribution due to high density of lipid membranes, loss of haemoglobin, myoglobin and the heat shock response, reduced anaerobic capacity, large myocytes with low ion exchange activities, and the use of lipid body stores for neutral buoyancy. Important trade-offs result from obligatory energy savings in the permanent cold: low metabolic rates support cold-compensated growth but imply narrow windows of thermal tolerance and reduced scopes for activity. The degree of thermal specialization is not uniformly defined by cold temperature but varies with life style characteristics and activity levels and associated aerobic scope. Trade-offs for the sake of cold compensated growth parallel reduced capacities for exercise performance, exacerbated by the effect of high haemolymph magnesium levels in crustaceans and, possibly, other invertebrates. High magnesium levels likely exclude the group of reptant decapod crustaceans from Antarctic waters below 0 °C. The hypothesis is developed that energy savings imposed by the permanent cold bear specific life history consequences. Due to effects of allometry, energy savings are exacerbated at small body size, favouring passive lecithotrophic larvae. At all stages of life history, reduced energy turnover for the sake of growth causes delays and low rates in other higher functions, with the result of late maturity, fecundity and offspring release, as well as extended development. As a consequence, extended life spans evolved due to life history requirements. At the same time, polar gigantism is enabled by a combination of elevated oxygen levels in cold waters, of reduced metabolism and of extended periods of growth at slow developmental rates.

  9. Trophic ecology of Lampanyctus crocodilus on north-west Mediterranean Sea slopes in relation to reproductive cycle and environmental variables.

    PubMed

    Fanelli, E; Papiol, V; Cartes, J E; Rodriguez-Romeu, O

    2014-06-01

    This study examined the population structure, reproductive cycle and feeding pattern of the lanternfish Lampanyctus crocodilus in the Balearic Basin (north-west Mediterranean Sea) from a depth of 450 to 1800?m and at a seasonal scale. Juveniles were mainly located at shallower depths, but also at deepest stations in autumn, while adults mostly inhabited intermediate depths with their centre of population density (CPD) located at 800-1000?m of depth. The migration of adults to deeper depths was detected in late summer to autumn, probably linked to the occurrence of nepheloid layers at c. 1200?m, which in turn enhances the biomass of the zooplankton prey. The diet was mainly based on euphausiids and mysids, with marked seasonal variations both on the upper (450-800 m) and lower (1000-1800 m), where suprabenthic gammariids and pelagic decapods were also dominant. Stomach fullness increased from winter to autumn on the US, while it had a maximum in spring on the LS, in parallel with high consumption of gelatinous zooplankton, which is probably more available after the phytoplankton bloom in late winter. Reproduction occurred in winter, confirmed by the higher percentage of mature females and high gonadosomatic indices (I(G)) at both depth ranges. Hepatosomatic indices (I(H)) showed an inverse trend to I(G) on the US, except in autumn, and was almost parallel on the LS, probably attributable to the migration of adults, which determined different temporal schemes in energy use and storage for reproduction on the US v. LS. Consistent with the different patterns observed at the two depth ranges, environmental drivers of fullness (i.e. feeding intensity) and I(G) (as a proxy of reproductive cycle) differed on the US and LS. The biomass of mysids and euphausiids was the greatest explanatory variables of fullness on the US and LS, pointing to the increasing feeding intensity when a resource was more available. I(H) also explained fullness, suggesting that greater feeding intensity in pre-reproductive periods enabled energy storage in the liver. I(G) was linked directly (i.e. mysids) or indirectly (i.e. surface primary production recorded 2 months before sampling) to food availability, implying a rapid response to vertical food inputs by deep-sea predators. Also, I(G) in L. crocodilus was related to population density, which suggests aggregations for reproduction. Estimates of L. crocodilus trophic levels, and of other accompanying mesopelagic fishes, indicated that the species feed through a continuum spanning the third trophic level, confirming the key role of mesopelagic fishes in transferring organic carbon between trophic levels. Trophic niche segregation among mesopelagic species was pronounced and non-overlapping groups could be distinguished because of the different vertical distribution and migratory behaviour. The study highlights the important role of the benthic boundary layer in sustaining benthopelagic communities in the deep Mediterranean Sea and the need to study the biology of a species throughout its whole depth range and not just at exploited depths (i.e. fishing grounds). PMID:24786723

  10. On two reports associated with James Wood-Mason and Alfred William Alcock published by the Indian Museum and the Indian Marine Survey between 1890 and 1891: implications for malacostracan nomenclature.

    PubMed

    Huys, Rony; Low, Martyn E Y; De Grave, Sammy; Ng, Peter K L; Clark, Paul F

    2014-01-01

    Two rare documents associated with the Indian Museum and the Indian Marine Survey for the administrative year April 1890 to March 1891 have been examined and found to have nomenclatural consequences for malacostracan crustaceans. Even though they constitute available published works according to the International Code for Zoological Nomenclature, these reports have rarely been cited. Dating these two publications is of importance as they make decapod scientific names available and, in a few instances, describe the same taxa. After searching the collections deposited in the Asian and African Room, British Library, the Administration Report of the Indian Marine for the year April 1890 to March 1891 could be dated with some degree of certainty as 25 August 1891. In contrast, dating the Indian Museum Annual Report proved more difficult because after examination of copies held by the General Library in the Natural History Museum, London, it was evident that not all of these reports were consistently published on time to meet an end of year deadline. However, the publication of volume XXII of the Indian Museum Annual Report for the year April 1890 to March 1891 appeared to be contemporary with the year printed at the bottom of the title page. As no exact date could be established with confidence, the publication date for this volume was fixed as 31 December 1891 in accordance with ICZN Art. 21.3.2. Therefore the Administration Report of the Indian Marine (published 25 August 1891) is considered to take precedence over the Indian Museum Annual Report (published 31 December 1891) and as such the names made available in the former take priority. As original copies of the Administration Report of the Indian Marine are not readily available in most libraries and few scientists have actually had access to these publications, the relevant Appendix No. XIII, in which the names of several malacostracan taxa are made available, is reproduced here. Since the appendix is not conclusively attributable to a specific author, it is considered to be written anonymously and should therefore be cited as Anonymous (1891). A number of names in Appendix No. XIII are available since they are accompanied by a brief description of the taxa they denote, and are either attributable to James Wood-Mason or remain with anonymous authorship; others are nomina nuda without a diagnosis or indication, or have been diagnosed previously in the "Natural History Notes from H.M. Indian Marine Survey Steamer Investigator". The nomenclatural implications for eight names made available in Anonymous (1891) are discussed: Glyphocrangon caeca, Glyphocrangon sculptus var. coecescens, Psalidopodidae, Psalidopus, Psalidopus mirabilis, Psathyrocaris, Psathyrocaris fragilis and Psopheticus crepitans. The nomenclatural history of various other taxa, initially denoted by unavailable names in Anonymous (1891), is also documented. The authorships of the various crustacean taxa collected by the Indian Marine Survey Steamer Investigator during the seasons 1889-1890 and 1890-1891, and published in two series of connected parts in the Annals and Magazine of Natural History, are also re-assessed and summarised. A rare document containing the list of R.I.M.S. Investigator stations for the period 1884-1913 is reproduced for the future benefit of the scientific community.  PMID:24869963

  11. Traceability of aquatic animals.

    PubMed

    Hĺstein, T; Hill, B J; Berthe, F; Lightner, D V

    2001-08-01

    Effective methods of traceability are urgently required for use in research as well as in different types of aquaculture operations and to control trade in aquatic animals and products. In regard to the marking of fish, many different tagging methods have been described and the method to be used depends on the purpose and need for tagging. In contrast, for molluscs and crustaceans, only a few methods of marking such animals have been described, due to the practical difficulties. The authors first describe the different methods for tracing fish and fishery products, by means of external tags, such as Floy tags, Carlin tags and passive integrated transponder tags; chemical marking using inorganic substances such as silver nitrate or potassium nitrate, pigments, oxytetracycline, etc.; and several different types of electronic devices in which basic information such as the strain of fish, farm of origin or weight can be stored. Genetic traceability using deoxyribonucleic acid profiling is developing quite rapidly for cultured brood stocks and wild populations. This technique may be used with very high degrees of confidence to assign to or exclude animals or products from their claimed origin, paternity or strain, and may be used as evidence in court proceedings. The second section of this paper describes the traceability of live molluscs for restocking and for human consumption. In these applications, genetic markers have been demonstrated to be suitable. Mechanical tagging on a small scale for research purposes has also been used. Otherwise, the only means of tracing live molluscs are the movement documents and the labelling on boxes that certifies the origin of the commodity. The third section describes the methods available for tracing live and dead crustaceans. A large variety of physical tagging methods for decapod crustaceans is described, such as the injection of biological stains (fast green, Niagara sky blue, trypan red and blue) and external tags such as coloured streamer tags, wire tags and a variety of anchor tags. Furthermore, a number of different internal coding methods, such as the coded micro-wire tags and injected elastomer tags are discussed in detail. As is the case for fish, genetic molecular techniques are also applied in population studies of crustaceans; some of the molecular genetic methods are described. Prawns for human consumption are most frequently packed whole or as tails after the necessary sorting, washing and freezing and the only way of performing a traceback is through documents relating to movement, invoices, health certificates and labelling of the boxes. The minimum requirements for labelling would be the content of the packages, i.e. species, quantity, identification of the manufacturer (name and address), packing place, importer/exporter or vendor of the product, in addition to the loading bill number. PMID:11548527

  12. Brain architecture of the largest living land arthropod, the Giant Robber Crab Birgus latro (Crustacea, Anomura, Coenobitidae): evidence for a prominent central olfactory pathway?

    PubMed Central

    2010-01-01

    Background Several lineages within the Crustacea conquered land independently during evolution, thereby requiring physiological adaptations for a semi-terrestrial or even a fully terrestrial lifestyle. Birgus latro Linnaeus, 1767, the giant robber crab or coconut crab (Anomura, Coenobitidae), is the largest land-living arthropod and inhabits Indo-Pacific islands such as Christmas Island. B. latro has served as a model in numerous studies of physiological aspects related to the conquest of land by crustaceans. From an olfactory point of view, a transition from sea to land means that molecules need to be detected in gas phase instead of in water solution. Previous studies have provided physiological evidence that terrestrial hermit crabs (Coenobitidae) such as B. latro have a sensitive and well differentiated sense of smell. Here we analyze the brain, in particular the olfactory processing areas of B. latro, by morphological analysis followed by 3 D reconstruction and immunocytochemical studies of synaptic proteins and a neuropeptide. Results The primary and secondary olfactory centers dominate the brain of B. latro and together account for ca. 40% of the neuropil volume in its brain. The paired olfactory neuropils are tripartite and composed of more than 1,000 columnar olfactory glomeruli, which are radially arranged around the periphery of the olfactory neuropils. The glomeruli are innervated ca. 90,000 local interneurons and ca. 160,000 projection neurons per side. The secondary olfactory centers, the paired hemiellipsoid neuropils, are targeted by the axons of these olfactory projection neurons. The projection neuron axonal branches make contact to ca. 250.000 interneurons (per side) associated with the hemiellipsoid neuropils. The hemiellipsoid body neuropil is organized into parallel neuropil lamellae, a design that is quite unusual for decapod crustaceans. The architecture of the optic neuropils and areas associated with antenna two suggest that B. latro has visual and mechanosensory skills that are comparable to those of marine Crustacea. Conclusions In parallel to previous behavioral findings that B. latro has aerial olfaction, our results indicate that their central olfactory pathway is indeed most prominent. Similar findings from the closely related terrestrial hermit crab Coenobita clypeatus suggest that in Coenobitidae, olfaction is a major sensory modality processed by the brain, and that for these animals, exploring the olfactory landscape is vital for survival in their terrestrial habitat. Future studies on terrestrial members of other crustacean taxa such as Isopoda, Amphipoda, Astacida, and Brachyura will shed light on how frequently the establishment of an aerial sense of olfaction evolved in Crustacea during the transition from sea to land. Amounting to ca. 1,000,000, the numbers of interneurons that analyse the olfactory input in B. latro brains surpasses that in other terrestrial arthropods, as e.g. the honeybee Apis mellifera or the moth Manduca sexta, by two orders of magnitude suggesting that B. latro in fact is a land-living arthropod that has devoted a substantial amount of nervous tissue to the sense of smell. PMID:20831795

  13. River-Borne Sediment Exports, Sedimentation Rates, and Influence on Benthos and Leaflitter Breakdown in Southern Caribbean Mangroves (uraba, Colombia)

    NASA Astrophysics Data System (ADS)

    Blanco, J. F.; Taborda, A.; Arroyave, A.

    2011-12-01

    Deposition of river-borne sediments is a major issue in coastal ecosystems worldwide, but no study has been conducted in Neotropical mangroves. Mangroves in the Urabá Gulf (Southern Caribbean coast of Colombia) receive one of the highest sediment loads (<0.10-0.77 x 106 ton yr-1) of the Caribbean region from rivers crossing an extensive banana crop district. Annual sedimentation rates were computed based in monthly samplings (2009-2010) in mangrove fringes across the Turbo River Delta using bottom-fixed 1L-cylinders (n=15). A significant spatial variation (0.04-0.9 ton m-2 yr-1) was observed among sampling stations within the delta, but the highest trapping occurred on river's main channel (2.54 ton m-2 yr-1). Temporal variation was smaller than spatial variation. Monitoring (twenty 1-m2 quadrats x 3 sites x 12 months) of a dominant mangrove-floor gastropod (Neritina virginea) observed a positive increase of density (4-125 ind. m-2: One-way ANOVA: p<0.001) along a sedimentation gradient (monthly means for low and high sedimentation sites: 3-69 kg m-2 yr-1). The role of N. virginea on leaflitter breakdown relative to sedimentation level was experimentally tested in a black mangrove (Avicennia germinans) stand by using 180 wire-mesh cages (15 x 15 x 25 cm) placed on the forest floor as experimental units, to prevent snail and crab access. After clearing existing snails and litter from the muddy bottom, each cage was placed and 1 senescent leaf of A. germinans and 7 snails were introduced (previously weighed) (snail abundance was similar to background densities). Three levels of area-weighed sedimentation rates (1, 3 and 18 g per cage) were daily added to test the impacts of the field-observed sedimentation gradient. The experiment was carried out during one month. Fresh leaf mass was different among treatments during the first week, increasing in proportion to the sedimentation rate probably due to leaf soaking. However, there was no difference in fresh leaf weight loss (average: 67%) among sediment levels after one month. Fresh weight loss (range: 81.6-4.4%) was observed in the snails during the early stage of the experiment. Significant differences were observed but not related to sediment levels. After one month, the snails gained weight (<1, 5, and 12%) in proportion to increased sediment levels (1, 3 and 18 g per day and cage). These results suggested that sedimentation levels observed in the study area are not detrimental for N. virginea populations and for their feeding activities. They also suggested that this species may cope with increased sedimentation by shifting feeding from leaflitter to sediments. However, the dominance by N. virginea (in number and biomass) in the study area may indicate that siltation is harmful for sensitive gastropods and for the entire benthic community, also including bivalves, decapods and polychaetes.

  14. Food web structure of the epibenthic and infaunal invertebrates on the Catalan slope (NW Mediterranean): Evidence from ? 13C and ? 15N analysis

    NASA Astrophysics Data System (ADS)

    Fanelli, E.; Papiol, V.; Cartes, J. E.; Rumolo, P.; Brunet, C.; Sprovieri, M.

    2011-01-01

    The food-web structure of the epibenthic and infaunal invertebrates on the continental slope of the Catalan Sea (Balearic basin, NW Mediterranean) was investigated using carbon and nitrogen stable isotopes on a total of 34 species, and HPLC pigment analyses for three key species. Samples were collected close to Barcelona (NE Iberian Peninsula), between 650 and 800 m depth and between February 2007 and February 2008. Mean ? 13C values ranged from -21.0‰ (small Calocaris macandreae and Amphipholis squamata) to -14.5‰ ( Sipunculus norvegicus). Values of ? 15N ranged from 4.0‰ ( A. squamata) to 12.1‰ ( Molpadia musculus). The stable isotope ratios of benthic fauna displayed a continuum of values (e.g. ? 15N range of 8‰), confirming a wide spectrum of feeding strategies (from active suspension feeders to predators) and complex food webs. According to the available information on diets of benthic fauna, the lowest values were found for surface deposit feeders (small C. macandrae and the two ophiuroids A. squamata and Amphiura chiajei) and active suspension feeders ( Abra longicallus and Scalpellum scalpellum) feeding on different sizes of particulate organic matter (POM), among which small particles may exhibit lower ? 15N. High annual mean ? 15N values were found among sub-surface deposit feeders, exploiting refractory or frequently recycled organic matter that is enriched in ? 15N. Carnivorous polychaetes ( Nephtys spp., Oenonidae and Polynoidae) and large decapods ( Geryon longipes and Paromola cuvieri) also displayed high ? 15N values. ? 13C ranges were particularly wide among surface deposit feeders (ranging from -21.0‰ to -16.4‰), suggesting exploitation of POM of both terrigenous and oceanic origins. Correlation between ? 13C and ? 15N was generally weak, indicating multiple carbon sources, likely due to the consumption of different kinds of sinking particles (e.g. marine snow, phytodetritus, etc.), sedimented and frequently recycled POM, together with macrophyte remains. The stronger ? 13C-? 15N correlations found in February and April suggest that during the period of water column homogeneization (winter-spring), the benthic community was sustained by phytodetritus inputs originating from the peak of surface primary production in February. Conversely, weaker ? 13C-? 15N correlations were observed during the period of water column stratification (beginning in June-July), suggesting that the benthic community in this period was sustained, with a delay of ca. 2/3 months, by multiple carbon sources including continental inputs from river discharge (with the maxima in April-May). Thus both advective and vertical fluxes seem to be food sources for benthos on the Catalonian slope. Pigments in the guts of key species were generally degraded, and only the active suspension feeder A. longicallus ingested fresh chlorophyll during periods of high primary production at the surface (February and April 2007).

  15. Growth patterns, chemical composition and oxygen consumption in early juvenile Hyas araneus (Decapoda: Majidae) reared in the laboratory

    NASA Astrophysics Data System (ADS)

    Anger, K.; Harms, J.; Christiansen, M. E.; Süsens, U.; Wilmes, B.

    1992-03-01

    Early (instar I and II) juveniles of the spider crab Hyas araneus were reared under constant conditions (12 °C, 32‰S) in the laboratory, and their growth, biochemical composition, and respiration were studied. Every second day, dry weight (W), ash-free dry weight (AFW), and contents of ash, organic and inorganic carbon (C), nitrogen (N), hydrogen (H), protein, chitin, lipid, and carbohydrates were measured, as well as oxygen consumption. Changes in the absolute amounts of W. AFW, and C, N, and H during the moulting cycle are described with various regression equations as functions of age within a given instar. These patterns of growth differ in part from those that have been observed during previous studies in larval stages of the same and some other decapod species, possibly indicating different growth strategies in larvae and juveniles. There were clear periodic changes in ash (% of W) and inorganic C (as % of total C), with initially very low and then steeply increasing values in postmoult, a maximum in intermoult, and decreasing figures during the premoult phase of each moulting cycle. Similar patterns were observed in the chitin fraction, reaching a maximum of 16% of W (31% of AFW). Ash, inorganic C, and chitin represent the major components of the exoskeleton and hence, changes in their amounts are associated with the formation and loss of cuticle material. Consequently, a high percentage of mineral matter was lost with the exuvia (76% of the late premoult [LPM] ash content, 74% of inorganic C), but relatively small fractions of LPM organic matter (15% of AFW, 11% of organic C, 5 6% of N and H). These cyclic changes in the cuticle caused an inverse pattern of variation in the percentage values (% of W) of AFW, organic C, N, H, and biochemical constituents other than chitin. When these measures of living biomass were related to, exclusively, the organic body fraction (AFM), much less variation was found during individual moulting cycles, with values of about 43 52% in organic C, 9 10% in N, 6 9% H, 31 49% of AFW in protein, 3 10% in lipid, and <1% in carbohydrates. All these constituents showed, on the average, a decreasing tendency during the first two crab instars, whereas N remained fairly constant. It cannot be explained at present, what other elements and biochemical compounds, respectively, might replace these decreasing components of AFW. Decreasing tendencies during juvenile growth were observed also in the organic C/N and in the lipid/protein weight ratios, both indicating that the proportion of lipid decreased at a higher rate than that of protein. Changes were observed also in the composition of inorganic matter, with significantly lower inorganic C in early postmoult (2 4% of ash) than in later stages of the moult cycle (about 9%). This reflected probably an increase in the degree of calcification, i.e. in the calcium carbonate content of the exoskeleton. As a fraction of total C, inorganic C reached maximum values of 17 and 20% in the crab I and II instars, respectively. The energy content of juvenile spider crabs was estimated independently from organic C and biochemical constituents, with a significant correlation between these values. However, the former estimates of energy were, on the average, significantly lower than the latter (slope of the regression ?1). Since organic C should be a reliable integrator of organic substances, but the sum of protein, lipid, chitin, and carbohydrates amounted to only 60 91% of AFW, it is concluded that the observed discrepancy between these two estimates of energy was caused by energy from biochemical constituents that had not been determined in our analyses. Thus, energy values obtained from these biochemical fractions alone may underestimate the actual amount of organic matter and energy. Respiration per individual in juvenile spider crabs was higher than that in larval stages of the same species (previous studies), but their W-specific values of oxygen consumption (QO2) were lower than in conspecific larvae (0.6 2?g O2·[mg W]-1). QO2 showed a consiste