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Sample records for juvenile crayfish pacifastacus

  1. Phylogenetic species delimitation for crayfishes of the genus Pacifastacus.

    PubMed

    Larson, Eric R; Castelin, Magalie; Williams, Bronwyn W; Olden, Julian D; Abbott, Cathryn L

    2016-01-01

    Molecular genetic approaches are playing an increasing role in conservation science by identifying biodiversity that may not be evident by morphology-based taxonomy and systematics. So-called cryptic species are particularly prevalent in freshwater environments, where isolation of dispersal-limited species, such as crayfishes, within dendritic river networks often gives rise to high intra- and inter-specific genetic divergence. We apply here a multi-gene molecular approach to investigate relationships among extant species of the crayfish genus Pacifastacus, representing the first comprehensive phylogenetic study of this taxonomic group. Importantly, Pacifastacus includes both the widely invasive signal crayfish Pacifastacus leniusculus, as well as several species of conservation concern like the Shasta crayfish Pacifastacus fortis. Our analysis used 83 individuals sampled across the four extant Pacifastacus species (omitting the extinct Pacifastacus nigrescens), representing the known taxonomic diversity and geographic distributions within this genus as comprehensively as possible. We reconstructed phylogenetic trees from mitochondrial (16S, COI) and nuclear genes (GAPDH), both separately and using a combined or concatenated dataset, and performed several species delimitation analyses (PTP, ABGD, GMYC) on the COI phylogeny to propose Primary Species Hypotheses (PSHs) within the genus. All phylogenies recovered the genus Pacifastacus as monophyletic, within which we identified a range of six to 21 PSHs; more abundant PSHs delimitations from GMYC and ABGD were always nested within PSHs delimited by the more conservative PTP method. Pacifastacus leniusculus included the majority of PSHs and was not monophyletic relative to the other Pacifastacus species considered. Several of these highly distinct P. leniusculus PSHs likely require urgent conservation attention. Our results identify research needs and conservation priorities for Pacifastacus crayfishes in western

  2. Phylogenetic species delimitation for crayfishes of the genus Pacifastacus

    PubMed Central

    Castelin, Magalie; Williams, Bronwyn W.; Olden, Julian D.; Abbott, Cathryn L.

    2016-01-01

    Molecular genetic approaches are playing an increasing role in conservation science by identifying biodiversity that may not be evident by morphology-based taxonomy and systematics. So-called cryptic species are particularly prevalent in freshwater environments, where isolation of dispersal-limited species, such as crayfishes, within dendritic river networks often gives rise to high intra- and inter-specific genetic divergence. We apply here a multi-gene molecular approach to investigate relationships among extant species of the crayfish genus Pacifastacus, representing the first comprehensive phylogenetic study of this taxonomic group. Importantly, Pacifastacus includes both the widely invasive signal crayfish Pacifastacus leniusculus, as well as several species of conservation concern like the Shasta crayfish Pacifastacus fortis. Our analysis used 83 individuals sampled across the four extant Pacifastacus species (omitting the extinct Pacifastacus nigrescens), representing the known taxonomic diversity and geographic distributions within this genus as comprehensively as possible. We reconstructed phylogenetic trees from mitochondrial (16S, COI) and nuclear genes (GAPDH), both separately and using a combined or concatenated dataset, and performed several species delimitation analyses (PTP, ABGD, GMYC) on the COI phylogeny to propose Primary Species Hypotheses (PSHs) within the genus. All phylogenies recovered the genus Pacifastacus as monophyletic, within which we identified a range of six to 21 PSHs; more abundant PSHs delimitations from GMYC and ABGD were always nested within PSHs delimited by the more conservative PTP method. Pacifastacus leniusculus included the majority of PSHs and was not monophyletic relative to the other Pacifastacus species considered. Several of these highly distinct P. leniusculus PSHs likely require urgent conservation attention. Our results identify research needs and conservation priorities for Pacifastacus crayfishes in western

  3. Horizontal transmission of Thelohania contejeani in the endangered white-clawed (Austropotamobius pallipes) and the invasive signal crayfish (Pacifastacus leniusculus).

    PubMed

    Imhoff, Emily M; Mortimer, Robert J G; Christmas, Martin; Dunn, Alison M

    2012-09-01

    The microsporidian parasite Thelohania contejeani causes porcelain disease and has been implicated in mass mortalities in populations of the endangered European crayfish Austropotamobius pallipes. However, the route of parasite transmission is not known. This paper investigates the horizontal transmission of T. contejeani between A. pallipes hosts as well as its transmissibility to the invasive signal crayfish (Pacifastacus leniusculus). Field collected juvenile A. pallipes and P. leniusculus were assigned to 1 of 3 experimental treatments; fed heavily infected A. pallipes tissue, exposed to water from tanks housing heavily parasitized A. pallipes, and a control group to provide an estimate of the baseline infection levels in the field. After 26 weeks, abdominal muscle samples were screened by PCR for T. contejeani. Infection was significantly higher in the treatment groups (83% in the cannibalism treatment, 42% in the water exposure treatment) than in the control group (4%), providing evidence for horizontal transmission of the parasite between A. pallipes hosts. Cannibalism and scavenging are common amongst crayfish, providing transmission opportunities in the field. The study also provides the first direct evidence for transmission of the parasite from an indigenous European crayfish species to the invasive signal crayfish, with 50% of P. leniusculus in each treatment, and 8% of control animals infected. We discuss the possibility that high density populations of the invasive signal crayfish may serve either as reservoirs or sinks for the parasite.

  4. Prevalence of the crayfish plague pathogen Aphanomyces astaci in populations of the signal crayfish Pacifastacus leniusculus in France: evaluating the threat to native crayfish.

    PubMed

    Filipová, Lenka; Petrusek, Adam; Matasová, Klára; Delaunay, Carine; Grandjean, Frédéric

    2013-01-01

    Aphanomyces astaci, the crayfish plague pathogen, first appeared in Europe in the mid-19(th) century and is still responsible for mass mortalities of native European crayfish. The spread of this parasite across the continent is especially facilitated by invasive North American crayfish species that serve as its reservoir. In France, multiple cases of native crayfish mortalities have been suggested to be connected with the presence of the signal crayfish Pacifastacus leniusculus, which is highly abundant in the country. It shares similar habitats as the native white-clawed crayfish Austropotamobius pallipes and, when infected, the signal crayfish might therefore easily transmit the pathogen to the native species. We investigated the prevalence of A. astaci in French signal crayfish populations to evaluate the danger they represent to local populations of native crayfish. Over 500 individuals of Pacifastacus leniusculus from 45 French populations were analysed, plus several additional individuals of other non-indigenous crayfish species Orconectes limosus, O. immunis and Procambarus clarkii. Altogether, 20% of analysed signal crayfish tested positive for Aphanomyces astaci, and the pathogen was detected in more than half of the studied populations. Local prevalence varied significantly, ranging from 0% up to 80%, but wide confidence intervals suggest that the number of populations infected by A. astaci may be even higher than our results show. Analysis of several individuals of other introduced species revealed infections among two of these, O. immunis and P. clarkii. Our results confirm that the widespread signal crayfish serves as a key reservoir of Aphanomyces astaci in France and therefore represents a serious danger to native crayfish species, especially the white-clawed crayfish. The prevalence in other non-indigenous crayfish should also be investigated as they likely contribute to pathogen transmission in the country.

  5. Eroded swimmeret syndrome in female crayfish Pacifastacus leniusculus associated with Aphanomyces astaci and Fusarium spp. infections.

    PubMed

    Edsman, Lennart; Nyström, Per; Sandström, Alfred; Stenberg, Marika; Kokko, Harri; Tiitinen, Vesa; Makkonen, Jenny; Jussila, Japo

    2015-01-15

    We describe a novel syndrome in crayfish, eroded swimmeret syndrome (ESS), affecting wild female signal crayfish Pacifastacus leniusculus. ESS causes partial or total swimmeret erosion. We observed ESS only in female signal crayfish larger than 40 mm carapace length, i.e. sexually mature and probably having carried eggs at least once. The eroded swimmerets were melanised, indicating a crayfish immune system response. We isolated Fusarium tricinctum species complex (SC), F. sambucinum SC, Saprolegnia parasitica and S. australis from the melanised tissue of the eroded swimmerets. ESS includes chronic Aphanomyces astaci infection and a secondary infection by Fusarium sp. In Sweden, we found female signal crayfish with ESS in 6 out of 11 populations with a prevalence below 1% in lakes with commercially productive signal crayfish populations and higher than 29% in lakes with documented signal crayfish population crashes. In Finland, the ESS prevalence was from 3.4 to 6.2% in a commercially productive population. None of the sampled male signal crayfish showed signs of ESS. A caging experiment indicated that females with at least 1 lost swimmeret carried on average 25% fewer fertilized eggs compared to females with intact swimmerets. ESS could significantly reduce individual female fecundity and thus could also affect fecundity at the population level. The decline in reproductive success due to ESS could be among the factors contributing to fluctuations in wild signal crayfish populations.

  6. Disturbance of fluvial gravel substrates by signal crayfish (Pacifastacus leniusculus)

    NASA Astrophysics Data System (ADS)

    Johnson, Matthew; Rice, Stephen; Reid, Ian

    2010-05-01

    The reworking of substrates by organisms, termed bioturbation, is considered a fundamental processes in marine and terrestrial environments but has remained relatively unstudied in fluvial environments. This studies looks at the bioturbation of fluvial gravel substrates by signal crayfish, an internationally important invasive species. We investigated the impact of signal crayfish activity in a laboratory flume. Bioturbation by crayfish on both loose arrangements of gravel and water-worked surfaces were studied and two sizes of narrowly-graded gravel were used; 11 - 16 mm and 16 - 22 mm. A laser scanner was used to obtain high resolution digital elevation models (DEMs) of gravel surfaces before and after crayfish activity. These DEMs were used to quantify topographic and structural changes to the surfaces due to the activity of crayfish. It was found that crayfish moved substantial quantities of material from all surfaces within six hours of introduction. The majority of the disturbance was associated with small scale (≤ 1 median grain diameter) movements of surface grains due to walking and foraging by crayfish. This textural change resulted in a structural alteration to the substrate surface. After six hours of crayfish activity, there was a 14% reduction in the imbrication of the grains from water-worked surfaces. Crayfish also constructed shallow pits and heaped excavated material into a series of mounds around its edge. Crayfish would always posture in pits in the same way. They would fold their vulnerable tails under their body and place their claws in front of their heads. When in pits crayfish predominately orientated themselves so they were facing an upstream direction. This implies that crayfish dig pits in order to streamline their bodies in the flow and lower their protrusion. Although pits and mounds contributed a relatively small proportion to the overall disturbance of substrates, they significantly increased the roughness of substrates. Pit and

  7. The long-term effects of invasive signal crayfish (Pacifastacus leniusculus) on instream macroinvertebrate communities.

    PubMed

    Mathers, Kate L; Chadd, Richard P; Dunbar, Michael J; Extence, Chris A; Reeds, Jake; Rice, Stephen P; Wood, Paul J

    2016-06-15

    Non-native species represent a significant threat to indigenous biodiversity and ecosystem functioning worldwide. It is widely acknowledged that invasive crayfish species may be instrumental in modifying benthic invertebrate community structure, but there is limited knowledge regarding the temporal and spatial extent of these effects within lotic ecosystems. This study investigates the long term changes to benthic macroinvertebrate community composition following the invasion of signal crayfish, Pacifastacus leniusculus, into English rivers. Data from long-term monitoring sites on 7 rivers invaded by crayfish and 7 rivers where signal crayfish were absent throughout the record (control sites) were used to examine how invertebrate community composition and populations of individual taxa changed as a result of invasion. Following the detection of non-native crayfish, significant shifts in invertebrate community composition were observed at invaded sites compared to control sites. This pattern was strongest during autumn months but was also evident during spring surveys. The observed shifts in community composition following invasion were associated with reductions in the occurrence of ubiquitous Hirudinea species (Glossiphonia complanata and Erpobdella octoculata), Gastropoda (Radix spp.), Ephemeroptera (Caenis spp.), and Trichoptera (Hydropsyche spp.); although variations in specific taxa affected were evident between regions and seasons. Changes in community structure were persistent over time with no evidence of recovery, suggesting that crayfish invasions represent significant perturbations leading to permanent changes in benthic communities. The results provide fundamental knowledge regarding non-native crayfish invasions of lotic ecosystems required for the development of future management strategies.

  8. The long-term effects of invasive signal crayfish (Pacifastacus leniusculus) on instream macroinvertebrate communities.

    PubMed

    Mathers, Kate L; Chadd, Richard P; Dunbar, Michael J; Extence, Chris A; Reeds, Jake; Rice, Stephen P; Wood, Paul J

    2016-06-15

    Non-native species represent a significant threat to indigenous biodiversity and ecosystem functioning worldwide. It is widely acknowledged that invasive crayfish species may be instrumental in modifying benthic invertebrate community structure, but there is limited knowledge regarding the temporal and spatial extent of these effects within lotic ecosystems. This study investigates the long term changes to benthic macroinvertebrate community composition following the invasion of signal crayfish, Pacifastacus leniusculus, into English rivers. Data from long-term monitoring sites on 7 rivers invaded by crayfish and 7 rivers where signal crayfish were absent throughout the record (control sites) were used to examine how invertebrate community composition and populations of individual taxa changed as a result of invasion. Following the detection of non-native crayfish, significant shifts in invertebrate community composition were observed at invaded sites compared to control sites. This pattern was strongest during autumn months but was also evident during spring surveys. The observed shifts in community composition following invasion were associated with reductions in the occurrence of ubiquitous Hirudinea species (Glossiphonia complanata and Erpobdella octoculata), Gastropoda (Radix spp.), Ephemeroptera (Caenis spp.), and Trichoptera (Hydropsyche spp.); although variations in specific taxa affected were evident between regions and seasons. Changes in community structure were persistent over time with no evidence of recovery, suggesting that crayfish invasions represent significant perturbations leading to permanent changes in benthic communities. The results provide fundamental knowledge regarding non-native crayfish invasions of lotic ecosystems required for the development of future management strategies. PMID:26974569

  9. Intensive removal of signal crayfish (Pacifastacus leniusculus) from rivers increases numbers and taxon richness of macroinvertebrate species

    PubMed Central

    Moorhouse, Tom P; Poole, Alison E; Evans, Laura C; Bradley, David C; Macdonald, David W

    2014-01-01

    Invasive species are a major cause of species extinction in freshwater ecosystems, and crayfish species are particularly pervasive. The invasive American signal crayfish Pacifastacus leniusculus has impacts over a range of trophic levels, but particularly on benthic aquatic macroinvertebrates. Our study examined the effect on the macroinvertebrate community of removal trapping of signal crayfish from UK rivers. Crayfish were intensively trapped and removed from two tributaries of the River Thames to test the hypothesis that lowering signal crayfish densities would result in increases in macroinvertebrate numbers and taxon richness. We removed 6181 crayfish over four sessions, resulting in crayfish densities that decreased toward the center of the removal sections. Conversely in control sections (where crayfish were trapped and returned), crayfish density increased toward the center of the section. Macroinvertebrate numbers and taxon richness were inversely correlated with crayfish densities. Multivariate analysis of the abundance of each taxon yielded similar results and indicated that crayfish removals had positive impacts on macroinvertebrate numbers and taxon richness but did not alter the composition of the wider macroinvertebrate community. Synthesis and applications: Our results demonstrate that non-eradication-oriented crayfish removal programmes may lead to increases in the total number of macroinvertebrates living in the benthos. This represents the first evidence that removing signal crayfish from riparian systems, at intensities feasible during control attempts or commercial crayfishing, may be beneficial for a range of sympatric aquatic macroinvertebrates. PMID:24634733

  10. Topographic disturbance of subaqueous gravel substrates by signal crayfish ( Pacifastacus leniusculus)

    NASA Astrophysics Data System (ADS)

    Johnson, Matthew F.; Rice, Stephen P.; Reid, Ian

    2010-11-01

    The impact of signal crayfish ( Pacifastacus leniusculus) on the topography and fabric of six narrowly graded, gravel substrates was investigated using repeat laser scanning of sediment surfaces in still-water aquaria. Digital Elevation Models (DEMs) of the gravel surfaces were obtained before and after exposure to crayfish for five predetermined periods. The impact on the substrate was quantified by establishing topographic and volumetric changes using DEMs of difference (DoD). The presence of an individual, medium sized crayfish for 24 h resulted in an average volume change in surface topography of 450 cm 3 over an area of 2400 cm 2, giving a sediment displacement of 1.7 kg m -2 d - 1 . The majority (78%) of this volume change was associated with small scale (≤ 1 median grain diameter) movements of surface grains. This fabric adjustment altered grain orientations and friction angles. Crayfish also constructed pits and mounds that increased significantly the roughness of the gravel substrates and altered the protrusion of individual grains. Crayfish were able to move material up to 38 mm in diameter that had a submerged weight six times that of the individuals used in this study. By modifying the arrangement of grains on the surface of fluvial substrates, signal crayfish may counteract the low flow physical consolidation of gravel beds and reduce the entrainment stresses required to move river bed material. The results of this study suggest that signal crayfish, an internationally widespread invasive species, may have substantial impacts on the physical environment of streams and rivers, as well as on local benthic ecological communities.

  11. Proteomic profiling of the signal crayfish Pacifastacus leniusculus egg and spermatophore.

    PubMed

    Niksirat, Hamid; Andersson, Liselotte; James, Peter; Kouba, Antonín; Kozák, Pavel

    2014-10-01

    Proteins of the signal crayfish Pacifastacus leniusculus egg and spermatophore were identified using in-gel digestion, mass spectrometry, and Mascot search. Forty-one and one-hundred-fifty proteins were identified in egg and spermatophore, respectively. The proteins were classified into nine categories including cell defence, cell signaling, cytoskeleton, DNA related activity, metabolism and energy production, protease and protease inhibitor, respiration, transportation, and others and unknown. Twenty-two proteins were found in both egg and spermatophore. The respiration and cytoskeleton groups are the most diverse categories in the protein profiles of the egg and spermatophore, respectively. No protein was assigned to DNA related activity and cell defence categories in the protein profile of the crayfish egg. Differences between protein profiles of the crayfish egg and spermatophore show different functional priorities for each of gametes. Several proteins having possible roles in gametogenesis, capacitation, acrosome reaction, and fertilization were identified. This proteomic profile of signal crayfish gametes provides a basis for further investigation of functional roles of the identified proteins in aspects of reproduction such as capacitation and fertilization.

  12. Accumulation and toxicity of aluminium-contaminated food in the freshwater crayfish, Pacifastacus leniusculus.

    PubMed

    Woodburn, Katie; Walton, Rachel; McCrohan, Catherine; White, Keith

    2011-10-01

    The accumulation and toxicity of aluminium in freshwater organisms have primarily been examined following aqueous exposure. This study investigated the uptake, excretion and toxicity of aluminium when presented as aluminium-contaminated food. Adult Pacifastacus leniusculus were fed control (3 μg aluminium/g) or aluminium-spiked pellets (420 μg aluminium/g) over 28 days. Half the crayfish in each group were then killed and the remainder fed control pellets for a further 10 days (clearance period). Concentrations of aluminium plus the essential metals calcium, copper, potassium and sodium were measured in the gill, hepatopancreas, flexor muscle, antennal gland (kidney) and haemolymph. Histopathological analysis of tissue damage and sub-cellular distribution of aluminium were examined in the hepatopancreas. Haemocyte number and protein concentration in the haemolymph were analysed as indicators of toxicity. The hepatopancreas of aluminium-fed crayfish contained significantly more aluminium than controls on days 28 and 38, and this amount was positively correlated with the amount ingested. More than 50% of the aluminium in the hepatopancreas of aluminium-fed crayfish was located in sub-cellular fractions thought to be involved in metal detoxification. Aluminium concentrations were also high in the antennal glands of aluminium-fed crayfish suggesting that some of the aluminium lost from the hepatopancreas is excreted. Aluminium exposure via contaminated food caused inflammation in the hepatopancreas but did not affect the number of circulating haemocytes, haemolymph ion concentrations or protein levels. In conclusion, crayfish accumulate, store and excrete aluminium from contaminated food with only localised toxicity.

  13. Histological changes and antioxidant enzyme activity in signal crayfish (Pacifastacus leniusculus) associated with sub-acute peracetic acid exposure.

    PubMed

    Chupani, Latifeh; Zuskova, Eliska; Stara, Alzbeta; Velisek, Josef; Kouba, Antonin

    2016-01-01

    Peracetic acid (PAA) is a powerful disinfectant recently adopted as a therapeutic agent in aquaculture. A concentration of 10 mg L(-1) PAA effectively suppresses zoospores of Aphanomyces astaci, the agent of crayfish plague. To aid in establishing safe therapeutic guideline, the effects of PAA on treated crayfish were investigated through assessment of histological changes and oxidative damage. Adult female signal crayfish Pacifastacus leniusculus (n = 135) were exposed to 2 mg L(-1) and 10 mg L(-1) of PAA for 7 days followed by a 7 day recovery period in clean water. Superoxide dismutase activity was significantly lower in gill and hepatopancreas after three days exposure to 10 mg L(1) PAA than in the group treated with 2 mg L(-1) PAA and a control in only clean water. Catalase activity in gill and hepatopancreas remained unaffected by both exposures. Glutathione reductase was significantly decreased in gill of 10 mg L(-1) PAA treated crayfish and increased in group exposed to 2 mg L(-1) compared to control after 7 days exposure. Antioxidant enzyme activity in exposed groups returned to control values after recovery period. Gill, hepatopancreas, and antennal gland showed slight damage in crayfish treated with 2 mg L(-1) of PAA compared to the control group. The extent and frequency of histological alterations were more pronounced in animals exposed to 10 mg L(-1). The gill was the most affected organ, infiltrated by granular hemocytes and displaying malformations of lamella tips and disorganization of epithelial cells. After a 7 day recovery period, the infiltrating cells in affected tissues of the exposed crayfish began to return to normal levels. Results suggested that the given concentrations could be applied to signal crayfish against crayfish plague agent in aquaculture; however, further studies are required for safe use. PMID:26611721

  14. Comparative ultrastructure of the spermatozoa of three crayfish species: Austropotamobius torrentium, Pacifastacus leniusculus, and Astacus astacus (Decapoda: Astacidae).

    PubMed

    Niksirat, Hamid; Kouba, Antonín; Rodina, Marek; Kozák, Pavel

    2013-07-01

    This study reports about the spermatozoal ultrastructure of three species of astacid crayfish, i.e., the stone crayfish Austropotamobius torrentium, signal crayfish Pacifastacus leniusculus, and noble crayfish Astacus astacus. The acrosome is a cup shaped and electron-dense structure at the anterior of the spermatozoon and comprises three layers of differing electron densities filled with parallel filaments that extend from the base to the apical zone. The acrosome was significantly longer in A. astacus than in P. leniusculus and the shortest acrosome belongs to A. torrentium. The width of the acrosome was significantly narrower in A. torrentium than in P. leniusculus and the widest acrosome belongs to A. astacus. The L:W ratio was significantly greater in A. torrentium than in P. leniusculus and the lowest ratio belongs to A. astacus. Radial arms are visible on each side of the acrosome or nucleus in sagittal view and wrap around the spermatozoon. Each radial arm comprises a parallel bundle of microtubules arranged along the long axis within a sheath. The nucleus, with decondensed material, is located in the posterior of the cell. All parts of the spermatozoon are tightly enclosed within an extracellular capsule. Despite a well-conserved general structure and similarity of pattern among these spermatozoa, differences in the dimensions of the acrosome within the studied species may be useful to help distinguish the different crayfish species.

  15. Distribution and Abundance of California Giant Salamander (Dicamptodon ensatus) and Signal Crayfish (Pacifastacus leniusculus) in the Upper Redwood Creek Watershed, Marin County, California

    USGS Publications Warehouse

    Fong, Darren; Howell, Judd A.

    2006-01-01

    A survey was conducted in 1997-1998 to identify the distribution of non-native signal crayfish (Pacifastacus leniusculus) and larval California giant salamanders (Dicamptodon ensatus) within the upper Redwood Creek watershed (Marin County, California). The crayfish is widely distributed along the mainstem Redwood Creek. It was found in lower Fern Creek but not in any first order tributaries or above fish barriers. While present throughout the study area, larval California giant salamanders were found mainly in small headwater tributaries. Larval salamanders appear to use habitats in accordance to their availability, while signal crayfish were rarely found in shallow water habitats and appeared to prefer scour pools. Evidence of predation by signal crayfish on larval giant salamanders was found under confined conditions. Controlled laboratory and field experiments would be needed to determine whether competitive exclusion is occurring. Because of its widespread occurrence in the headwater streams surveyed in this project, California giant salamanders would be an appropriate indicator species for those interested in monitoring the health of small headwater streams. Future long-term monitoring using California giant salamanders should be based on permanent monitoring reaches with periodic basinwide habitat and animal surveys to determine if reaches are representative of basinwide conditions.

  16. Does juvenile competition explain displacement of a native crayfish by an introduced crayfish?

    USGS Publications Warehouse

    Larson, E.R.; Magoulick, D.D.

    2009-01-01

    The coldwater crayfish Orconectes eupunctus is endemic to the Spring and Eleven Point Rivers of Arkansas and Missouri, and appears to have been displaced from a portion of its range by the recently introduced ringed crayfish Orconectes neglectus. We examined competition among juveniles as a potential mechanism for this crayfish species displacement through laboratory and field experiments. Orconectes eupunctus juveniles survived and grew in stream cages in their former range, implicating biotic interactions rather than habitat degradation in the displacement. Laboratory experiments revealed O. neglectus juveniles were dominant in the presence of limited food, whereas size rather than species determined occupancy of limited shelter. In a field competition experiment using stream cages, O. neglectus juveniles did not inhibit growth or reduce survival of O. eupunctus juveniles. Consequently, laboratory evidence of O. neglectus dominance did not correspond with competition under field conditions. Combined with previous studies examining the effects of O. neglectus on O. eupunctus, these results suggest that competition may not be a factor in this crayfish species displacement. Alternate mechanisms for the apparent displacement of O. eupunctus by O. neglectus, such as differential predation or reproductive interference, should be investigated. ?? 2008 Springer Science+Business Media B.V.

  17. Protein modification in the post-mating spermatophore of the signal crayfish Pacifastacus leniusculus: insight into the tyrosine phosphorylation in a non-motile spermatozoon.

    PubMed

    Niksirat, Hamid; Vancová, Marie; Andersson, Liselotte; James, Peter; Kouba, Antonín; Kozák, Pavel

    2016-09-01

    After mating, spermatophores of signal crayfish are stored on the body of the female for a period before fertilization. This study compared the post-mating protein profile and pattern of protein tyrosine phosphorylation of the signal crayfish spermatophore to that of the freshly ejaculated spermatophore and found substantial differences. Two major bands of tyrosine-phosphorylated proteins of molecular weights 10 and 50kDa were observed in the freshly ejaculated spermatophore of the signal crayfish. While the tyrosine-phosphorylated protein band with molecular weight 10kDa was formed by protein(s) of similar pH, the band with molecular weight of 50kDa consisted of proteins of varying pH. In the post-mating spermatophore, the band with molecular weight of 50kDa was not detected, and an increase in the level of protein tyrosine phosphorylation was observed in the 10kDa band. The microtubular radial arms of the spermatozoon showed a positive reaction to an anti-tyrosine antibody conjugated with gold particles in both the freshly ejaculated and post-mating spermatophores. In conclusion, the male gamete of the signal crayfish undergoes molecular modification during post-mating storage on the body of the female including changes in the level of protein expression and protein tyrosine phosphorylation. Structural similarity of the radial arms in the crayfish immotile spermatozoon with flagellum, which is the main site of protein tyrosine phosphorylation in the mammalian motile spermatozoa, raises questions regarding evolution and function of such organelles across the animal kingdom that must be addressed in the future studies. PMID:27481552

  18. Development of agonistic encounters in dominance hierarchy formation in juvenile crayfish.

    PubMed

    Sato, Daisuke; Nagayama, Toshiki

    2012-04-01

    We have characterized the behavioural patterns of crayfish during agonistic bouts between groups of crayfish of four different body lengths (9-19, 20-32, 41-48 and 69-75 mm) to characterize changes in the patterns of agonistic encounter during development. The behaviour of both dominant and subordinate animals was analysed by single frame measurement of video recordings. Behavioural acts that occurred during agonistic bouts were categorized as one of seven types: capture, fight, contact, approach, retreat, tailflip and neutral. Dominant-subordinate relationships were formed between juvenile crayfish as early as the third stage of development. Patterns of agonistic bouts to determine social hierarchy became more aggressive during development. The dominant-subordinate relationship was usually determined after contact in crayfish of less than 20 mm and 20-32 mm in length, while several bouts of fights were necessary for crayfish of 41-48 and 69-75 mm in length. Furthermore, social hierarchy was formed more rapidly in small crayfish. In larger animals, the number of approaches by dominant animals that promoted retreat in subordinate animals increased after the establishment of the winner-loser relationship. In smaller crayfish, in contrast, no measurable changes in these behaviour patterns were observed before and after the establishment of the winner-loser relationship. With increasing body size, the probability of tailflips decreased while that of retreats increased as the submissive behavioural act of subordinate animals.

  19. Sublethal exposure to cadmium interferes with cover-seeking behavior of juvenile crayfish, Procambarus clarkii (Girard)

    SciTech Connect

    Misra, R.; Antonelli, J.; Misra, K.; Steele, C.; Skinner, C.

    1996-12-31

    The behavioral effects of heavy metals on crayfishes may significantly affect their survival in the environment. Changes in their ability to remain under cover could substantially decrease their survivorship due to increased predation. The effect of sublethal cadmium exposure on the ability of juvenile crayfish to remain in cover was evaluated. Four different treatment groups wee used: a control group and three experimental groups exposed to 1, 2, or 3 mg Cd/L for 7 d. Crayfish were placed, individually, into glass aquaria containing 3 L of laboratory water pre-treated to detoxify all heavy metals, with continuous aeration. Each crayfish was provided with a dark, thigmotactic shelter. Cadmium was introduced into the aquaria on days 1 and 4 to maintain the nominal concentrations. Beginning on day 5 and continuing through day 7, observations were taken on each crayfish five times per day, with a minimum of 30 minutes between observations. Crayfish position was recorded as in cover or in the open area of an aquarium. Juveniles in the control groups were in cover 78.35 of the observations. Over the 3 d of observations, juveniles in the 1 mg Cd/L exposure groups used cover 72.1%. Those in the 2 and 3 mg Cd/L groups used cover 53.9% and 60%, respectively, indicating hyperactivity induced by cadmium exposure. Examining the daily results, however, those juveniles in the 1 mg Cd/L group were in cover only 60% of the time by day 7, indicating a latency to produce hyperactivity at this concentration.

  20. Thermal resistance of juvenile crayfish, Cambarus bartoni (Fabricius): experiment and model

    SciTech Connect

    Cox, D.K.; Beauchamp, J.J.

    1982-07-01

    Juvenile crayfish, Cambarus bartoni, were subjected to acute thermal changes after being acclimated to temperatures of 15, 20 or 25 C for at least 1 week. Groups of 10 individuals each were exposed to various combinations of time and temperature, after which they were returned to their original acclimation temperature. Observations of latent mortality made 72 hr later indicated that some crayfish experience lethal temperature stress between 30 and 33 C; their ultimate upper incipient lethal temperature is estimated to be 32.5 C. A linear logistic model was used to construct contours of constant mortality (30, 50 and 90%) as a function of time and temperature.

  1. Thermal resistance of juvenile crayfish, Cambarus bartoni (fabricius): experiment and model

    SciTech Connect

    Cox, D.K.; Beauchamp, J.J.

    1982-01-01

    Juvenile crayfish, Cambarus bartoni, were subjected to acute thermal changes after being acclimated to temperatures of 15, 20 or 25 C for at least 1 week. Groups of 10 individuals each were exposed to various combinations of time and temperature, after which they were returned to their original acclimation temperature. Observations of latent mortality made 72 hr later indicated that some crayfish experience lethal temperature stress between 30 and 33 C; their ultimate upper incipient lethal temperature is estimated to be 32.5 C. A linear logistic model was used to construct contours of constant mortality (30, 50 and 90%) as a function of time and temperature.

  2. Do environmental changes or juvenile competition act as mechanisms of species displacement in crayfishes?

    USGS Publications Warehouse

    Westhoff, J.T.; DiStefano, R.J.; Magoulick, D.D.

    2012-01-01

    The Big Creek Crayfish, Orconectes peruncus, is native to the St. Francis River drainage in Missouri, USA and is often absent where the introduced Woodland Crayfish, Orconectes hylas, has established. We performed a field experiment to determine whether effects of current abiotic conditions and interspecific competition with O. hylas were responsible for displacement of O. peruncus from parts of their former range. We examined growth and survival of juvenile male O. peruncus exposed to juvenile male O. hylas in enclosures at two sites in the former range of O. peruncus. Enclosures contained 8 (low density) or 16 individuals (high density) and had O. peruncus only (control) or both species (interspecific treatment). Juvenile O. peruncus were able to survive and grow in portions of their former range, implicating biotic versus abiotic factors in the displacement of O. peruncus. Survival rates of O. peruncus did not differ among treatments at either site. Orconectes peruncus showed significant growth in all treatments and interspecific effects were not greater than intraspecific effects on O. peruncus growth rates. High-density treatments showed significantly reduced O. peruncus growth rates compared to low-density treatments, except in Carver Creek interspecific treatments. When considered in the context of previous studies examining the effects of O. hylas on O. peruncus, results suggest that neither direct competition between juvenile males of the two species or abiotic change are responsible for the decreased range of O. peruncus. Additional research is required to determine the mechanism(s) driving the displacement of O. peruncus. ?? 2011 Springer Science+Business Media B.V.

  3. Effects of sublethal exposure to cadmium on shelter-seeking behavior of juvenile Orconectes rusticus (Girard) crayfish

    SciTech Connect

    Alberstadt, P.; Steele, C.; Misra, K.; Skinner, C.; Wilson, B.; Robaskiewicz, S.

    1999-07-01

    Sublethal behavioral effect of heavy metals on crayfishes may adversely effect their survival in the environment. They may experience increased predation due to changes in their ability to remain in or under shelter. The effect of sublethal cadmium exposure on the ability of juvenile Orconectes rusticus crayfish to remain in shelter was evaluated. Four different treatment groups were used: a control group not exposed to cadmium, and three experimental groups exposed to 1, 2 ,or 3 mg Cd/L for 7 days. Crayfish were placed, individually, into small glass aquaria containing 3 L of laboratory water, with continuous aeration. Each crayfish was provided with a dark, thigmotactic shelter. Cadmium was introduced into the aquaria on days 1 and 4 to establish and maintain the nominal concentration. On days 5 through 7, observations were taken on each crayfish five times per day, with a minimum of 30 minutes between observations. The locations of the animals were recorded as in cover or in the open area of an aquarium. Repeated measures ANOVA was used to examine the effects of sublethal exposure to cadmium on shelter use by the juveniles.

  4. Toxicity thresholds for juvenile freshwater mussels Echyridella menziesii and crayfish Paranephrops planifrons, after acute or chronic exposure to Microcystis sp.

    PubMed

    Clearwater, S J; Wood, S A; Phillips, N R; Parkyn, S M; Van Ginkel, R; Thompson, K J

    2014-05-01

    Survival of juvenile freshwater mussels (Echyridella menziesii (Gray, 1843) formerly known as Hyridella menziesi) and crayfish (Paranephrops planifrons, White, 1842) decreased after four days exposure to microcystin-containing cell-free extracts (MCFE) of Microcystis sp. at concentrations typical of severe cyanobacterial blooms. Crayfish survival was 100, 80, and 50% in microcystin concentrations of 1339, 2426, and 11146 μg L(-1) respectively, and shade- and shelter-seeking behavior was negatively affected when concentrations were ≥2426 μg L(-1) . Mussel survival decreased to 92% and reburial rates decreased to 16% after exposure for 96 h to MCFE containing microcystins at concentrations of 5300 μg L(-1) . Crayfish survival was 100% when fed freeze-dried Microcystis sp. incorporated into an artificial diet (6-100 μg microcystin kg(-1) ww) at dietary doses from 0.03 to 0.55 μg g(-1) body weight d(-1) for 27 days. Specific growth rate was significantly lower in crayfish fed ≥0.15 μg g(-1) body weight day(-1) compared with controls, but not compared with a diet incorporating nontoxic cyanobacteria. Microcystins accumulated preferentially in crayfish hepatopancreas and mussel digesta as MCFE or dietary concentrations increased. These laboratory data indicate that, assuming dissolved oxygen concentrations remain adequate, and no simultaneous exposure to live Microcystis sp. cells, cell-free microcystins will only be a significant stressor to juvenile crayfish and mussels in severe Microcystis sp. blooms. In contrast, crayfish were negatively affected by relatively low concentrations of microcystins in artificial diets compared with those measured locally in benthic cyanobacterial mats.

  5. Effect of temperature on heavy metal toxicity to juvenile crayfish, Orconectes immunis (Hagen).

    PubMed

    Khan, M A Q; Ahmed, S A; Catalin, Bogdon; Khodadoust, A; Ajayi, Oluwaleke; Vaughn, Mark

    2006-10-01

    The acute toxicity of four selected heavy metals to juvenile crayfish Orconectes immunis (Hagen) (1-2 g wet body wt. each) at room temperature increased in the following order: cadmium (x3) < copper (x10) < zinc (x2) < lead. The toxicity of these metals to crayfish acclimated at 17, 20, 23/24, and 27 degrees C increased with temperature (by 7-20% between 20 and 24 degrees C and 14-26% between 20 and 27 degrees C) as judged by the lowering of LT(50) (time to kill 50% of test animals at a fixed concentration) values. A 4 degrees C rise in temperature (from 20 to 24 degrees C), which increased the toxicity of copper by about 7%, increased the rate of oxygen consumption by about 34%. Heavy metals inhibited the rate of oxygen consumption at all temperatures. In 20 degrees C-acclimated crayfish, copper caused about 17% inhibition of oxygen consumption compared to about 7-12% by other metals including the most toxic cadmium. A 3-4 degrees C rise in temperature tripled the inhibitory effect of copper (20%), cadmium and zinc (26 and 18%, respectively), but not of lead, on oxygen consumption. A 7 degrees C-rise in temperature (from 20 to 27 degrees C) increased the inhibitory effect of heavy metals, including lead, on oxygen consumption by up to 54% in the case of copper. The data indicate that rising global temperatures (currently 0.60 degrees C) associated with climate change can have the potential to increase the sensitivity of aquatic animals to heavy metals in their environment.

  6. Effects of atrazine on growth and sex differentiation, in juveniles of the freshwater crayfish Cherax quadricarinatus.

    PubMed

    Mac Loughlin, Camila; Canosa, Ivana S; Silveyra, Gabriela R; López Greco, Laura S; Rodríguez, Enrique M

    2016-09-01

    The effect of the herbicide atrazine was assayed in early juveniles of the redclaw crayfish Cherax quadricarinatus. Four cohorts of juveniles (a total of 280 animals) were exposed for 4 wk to each one of three atrazine concentrations (0.1, 0.5 and 2.5mg/L) or a control (0mg/L), from a commercial formulation having 90% of active principle. At the end of the exposure, no significant (p>0.05) differences in either mortality or molting were noted. However, the weight gain and the protein content of abdominal muscle decreased significantly (p<0.05) in the highest atrazine concentration as compared to control, indicating that atrazine acted as a relevant stressor, although at a concentration higher than those reported in the environment. Besides, the proportion of females increased progressively as the atrazine concentration increases, being significantly (p<0.05) higher than that of controls at the highest concentration assayed. Both macroscopic and histological analysis revealed a normal architecture of gonopores and gonads in both control and exposed animals. The obtained results strongly suggest that atrazine could be causing an endocrine disruption on the hormonal system responsible for the sexual differentiation of the studied species, increasing the proportion of female proportion without disturbing the gonad structure. PMID:27213565

  7. Effects of atrazine on growth and sex differentiation, in juveniles of the freshwater crayfish Cherax quadricarinatus.

    PubMed

    Mac Loughlin, Camila; Canosa, Ivana S; Silveyra, Gabriela R; López Greco, Laura S; Rodríguez, Enrique M

    2016-09-01

    The effect of the herbicide atrazine was assayed in early juveniles of the redclaw crayfish Cherax quadricarinatus. Four cohorts of juveniles (a total of 280 animals) were exposed for 4 wk to each one of three atrazine concentrations (0.1, 0.5 and 2.5mg/L) or a control (0mg/L), from a commercial formulation having 90% of active principle. At the end of the exposure, no significant (p>0.05) differences in either mortality or molting were noted. However, the weight gain and the protein content of abdominal muscle decreased significantly (p<0.05) in the highest atrazine concentration as compared to control, indicating that atrazine acted as a relevant stressor, although at a concentration higher than those reported in the environment. Besides, the proportion of females increased progressively as the atrazine concentration increases, being significantly (p<0.05) higher than that of controls at the highest concentration assayed. Both macroscopic and histological analysis revealed a normal architecture of gonopores and gonads in both control and exposed animals. The obtained results strongly suggest that atrazine could be causing an endocrine disruption on the hormonal system responsible for the sexual differentiation of the studied species, increasing the proportion of female proportion without disturbing the gonad structure.

  8. Toxicity of cadmium and lead to juvenile red swamp crayfish, Procambarus clarkii, and effects on fecundity of adults

    SciTech Connect

    Naqvi, S.M.; Howell, R.D. )

    1993-08-01

    Heavy metals such as Cd and Pb may affect aquatic organisms adversely if they are sublethally exposed for a long time. Acute toxicities of a number of heavy metals to different species of crayfish have been reported by several investigators. However, the chronic toxicities of different heavy metals have not been reported as frequently. P. clarkii is of considerable commercial importance to the economy of Louisiana, which produces 98% of the total harvest of the US, worth approximately 143 million dollars annually. This prompted us to use this crayfish for: (1) determining the 96-hr LC[sub 50] values for Cd and Pb using juvenile P. clarkii and (2) assessing the chronic effects of Cd and Pb on the fecundity of adults and hatching success of metal-exposed eggs. 12 refs., 4 tabs.

  9. Compensatory Growth in Juveniles of Freshwater Redclaw Crayfish Cherax quadricarinatus Reared at Three Different Temperatures: Hyperphagia and Food Efficiency as Primary Mechanisms.

    PubMed

    Stumpf, Liane; López Greco, Laura S

    2015-01-01

    Feeding restriction, as a trigger for compensatory growth, might be considered an alternative viable strategy for minimizing waste as well as production costs. The study assessed whether juvenile redclaw crayfish Cherax quadricarinatus (initial weight 0.99 ± 0.03 g) was able to compensate for feeding restriction at different temperatures (23 ± 1, 27 ± 1 and 31 ± 1 ° C). Hyperphagia, food utilization efficiency, energetic reserves, and hepatopancreas structure were analyzed. Three temperatures and two feeding regimes (DF-daily fed throughout the experiment and CF- 4 days food deprivation followed by 4 days of feeding, intermittently) were tested. The restriction period was from day 1 to 45, and the recovery period was from day 45 to 90. The previously restricted crayfish held at 23, 27, and 31 ± 1 ° C displayed complete body weight catch-up through compensatory growth following the restriction period with depressed growth. The mechanisms that might explain this response were higher feed intake (hyperphagia), and increased food utilization efficiency. Hepatopancreatic lipids were used as a metabolic fuel and hepatosomatic index was reduced in the previously restricted crayfish, but recovery at the same level of unrestricted crayfish occurred after the shift to daily feeding. The highest temperature affected adversely growth, feed intake, food efficiency, and metabolism of crayfish, whereas the lowest temperature and feeding restriction induced a more efficient growth of the crayfish.

  10. Compensatory Growth in Juveniles of Freshwater Redclaw Crayfish Cherax quadricarinatus Reared at Three Different Temperatures: Hyperphagia and Food Efficiency as Primary Mechanisms

    PubMed Central

    Stumpf, Liane; López Greco, Laura S.

    2015-01-01

    Feeding restriction, as a trigger for compensatory growth, might be considered an alternative viable strategy for minimizing waste as well as production costs. The study assessed whether juvenile redclaw crayfish Cherax quadricarinatus (initial weight 0.99 ±0.03 g) was able to compensate for feeding restriction at different temperatures (23±1, 27±1 and 31±1°C). Hyperphagia, food utilization efficiency, energetic reserves, and hepatopancreas structure were analyzed. Three temperatures and two feeding regimes (DF-daily fed throughout the experiment and CF- 4 days food deprivation followed by 4 days of feeding, intermittently) were tested. The restriction period was from day 1 to 45, and the recovery period was from day 45 to 90. The previously restricted crayfish held at 23, 27, and 31 ± 1°C displayed complete body weight catch-up through compensatory growth following the restriction period with depressed growth. The mechanisms that might explain this response were higher feed intake (hyperphagia), and increased food utilization efficiency. Hepatopancreatic lipids were used as a metabolic fuel and hepatosomatic index was reduced in the previously restricted crayfish, but recovery at the same level of unrestricted crayfish occurred after the shift to daily feeding. The highest temperature affected adversely growth, feed intake, food efficiency, and metabolism of crayfish, whereas the lowest temperature and feeding restriction induced a more efficient growth of the crayfish. PMID:26422508

  11. Distribution and epidemiology of genotypes of the crayfish plague agent Aphanomyces astaci from noble crayfish Astacus astacus in Finland.

    PubMed

    Viljamaa-Dirks, S; Heinikainen, S; Torssonen, H; Pursiainen, M; Mattila, J; Pelkonen, S

    2013-04-11

    The crayfish plague agent Aphanomyces astaci was isolated from 69 noble crayfish Astacus astacus samples in Finland between 1996 and 2006. All isolates were genotyped using randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). Altogether, 43 isolates belonged to the genotype group of Astacus strains (As), which is assumed to represent the genotype originally introduced into Europe around 1860 and into Finland in 1893. There were 26 crayfish plague isolates belonging to the group of Pacifastacus strain I (Ps1), which appeared in Europe after the stocking of the North American species signal crayfish Pacifastacus leniusculus. The geographical distribution of the 2 genotypes in Finland corresponded with the stocking strategies of signal crayfish. The majority of Ps1-strains (83%) were associated with a classical crayfish plague episode involving acute mortality, compared with only 33% of the As-strains. As-strains were found more often by searching for reasons for population declines or permanently weak populations, or through cage experiments in connection with reintroduction programmes. In some water bodies, isolations of the As-strains were made in successive years. This study shows that persistent crayfish plague infection is not uncommon in noble crayfish populations. The described epidemiological features suggest a difference in virulence between these 2 genotypes.

  12. Mercury and trace elements in crayfish from northern California

    USGS Publications Warehouse

    Hothem, R.L.; Bergen, D.R.; Bauer, M.L.; Crayon, J.J.; Meckstroth, A.M.

    2007-01-01

    We collected two species of crayfish, Pacifastacus leniusculus and Procambarus clarkii, from Cache and Putah Creeks, California, and analyzed them for mercury and trace elements. Trace elements were higher in carcasses in 40 cases, higher in tails in 5 cases, and not different in 35 cases; no concentration exceeded levels considered harmful. Mercury concentrations were similar among sites, with no overall sex or species effect in tails. Mercury and methylmercury concentrations were higher in tails at all sites. Methylmercury concentrations in crayfish tails (0.156-0.256 ??g/g) exceeded concentrations reported in health advisories for consumption of fish and crayfish from these watersheds. ?? Springer Science+Business Media, LLC 2007.

  13. Mercury and trace elements in crayfish from northern california.

    PubMed

    Hothem, Roger L; Bergen, Darrin R; Bauer, Marissa L; Crayon, John J; Meckstroth, Anne M

    2007-12-01

    We collected two species of crayfish, Pacifastacus leniusculus and Procambarus clarkii, from Cache and Putah Creeks, California, and analyzed them for mercury and trace elements. Trace elements were higher in carcasses in 40 cases, higher in tails in 5 cases, and not different in 35 cases; no concentration exceeded levels considered harmful. Mercury concentrations were similar among sites, with no overall sex or species effect in tails. Mercury and methylmercury concentrations were higher in tails at all sites. Methylmercury concentrations in crayfish tails (0.156-0.256 microg/g) exceeded concentrations reported in health advisories for consumption of fish and crayfish from these watersheds. PMID:18046498

  14. Bacteria-Induced Dscam Isoforms of the Crustacean, Pacifastacus leniusculus.

    PubMed

    Watthanasurorot, Apiruck; Jiravanichpaisal, Pikul; Liu, Haipeng; Söderhäll, Irene; Söderhäll, Kenneth

    2011-06-01

    The Down syndrome cell adhesion molecule, also known as Dscam, is a member of the immunoglobulin super family. Dscam plays an essential function in neuronal wiring and appears to be involved in innate immune reactions in insects. The deduced amino acid sequence of Dscam in the crustacean Pacifastacus leniusculus (PlDscam), encodes 9(Ig)-4(FNIII)-(Ig)-2(FNIII)-TM and it has variable regions in the N-terminal half of Ig2 and Ig3 and the complete Ig7 and in the transmembrane domain. The cytoplasmic tail can generate multiple isoforms. PlDscam can generate more than 22,000 different unique isoforms. Bacteria and LPS injection enhanced the expression of PlDscam, but no response in expression occurred after a white spot syndrome virus (WSSV) infection or injection with peptidoglycans. Furthermore, PlDscam silencing did not have any effect on the replication of the WSSV. Bacterial specific isoforms of PlDscam were shown to have a specific binding property to each tested bacteria, E. coli or S. aureus. The bacteria specific isoforms of PlDscam were shown to be associated with bacterial clearance and phagocytosis in crayfish.

  15. Passive samplers accurately predict PAH levels in resident crayfish.

    PubMed

    Paulik, L Blair; Smith, Brian W; Bergmann, Alan J; Sower, Greg J; Forsberg, Norman D; Teeguarden, Justin G; Anderson, Kim A

    2016-02-15

    Contamination of resident aquatic organisms is a major concern for environmental risk assessors. However, collecting organisms to estimate risk is often prohibitively time and resource-intensive. Passive sampling accurately estimates resident organism contamination, and it saves time and resources. This study used low density polyethylene (LDPE) passive water samplers to predict polycyclic aromatic hydrocarbon (PAH) levels in signal crayfish, Pacifastacus leniusculus. Resident crayfish were collected at 5 sites within and outside of the Portland Harbor Superfund Megasite (PHSM) in the Willamette River in Portland, Oregon. LDPE deployment was spatially and temporally paired with crayfish collection. Crayfish visceral and tail tissue, as well as water-deployed LDPE, were extracted and analyzed for 62 PAHs using GC-MS/MS. Freely-dissolved concentrations (Cfree) of PAHs in water were calculated from concentrations in LDPE. Carcinogenic risks were estimated for all crayfish tissues, using benzo[a]pyrene equivalent concentrations (BaPeq). ∑PAH were 5-20 times higher in viscera than in tails, and ∑BaPeq were 6-70 times higher in viscera than in tails. Eating only tail tissue of crayfish would therefore significantly reduce carcinogenic risk compared to also eating viscera. Additionally, PAH levels in crayfish were compared to levels in crayfish collected 10 years earlier. PAH levels in crayfish were higher upriver of the PHSM and unchanged within the PHSM after the 10-year period. Finally, a linear regression model predicted levels of 34 PAHs in crayfish viscera with an associated R-squared value of 0.52 (and a correlation coefficient of 0.72), using only the Cfree PAHs in water. On average, the model predicted PAH concentrations in crayfish tissue within a factor of 2.4 ± 1.8 of measured concentrations. This affirms that passive water sampling accurately estimates PAH contamination in crayfish. Furthermore, the strong predictive ability of this simple model suggests

  16. Potent infection reservoir of crayfish plague now permanently established in Norway.

    PubMed

    Vrålstad, Trude; Johnsen, Stein I; Fristad, Rosa Ferreira; Edsman, Lennart; Strand, David

    2011-11-01

    Noble crayfish Astacus astacus is threatened in Europe due to invasive crayfish carrying the crayfish plague agent Aphanomyces astaci. Norway is among the last countries in which the introduction of non-indigenous crayfish has been limited through strict legislation practices. However, North American signal crayfish Pacifastacus leniusculus were recently discovered in a water-course that has been repeatedly hit by the plague. We mapped the distribution and relative density (catch per unit effort) of signal crayfish within this lake, and performed agent-specific real-time PCR to estimate the prevalence of A. astaci in the population. The resulting length frequencies and relative density estimates clearly demonstrate a well-established signal crayfish population, in which 86.4% of the analysed individuals were confirmed carriers. The success of detection was significantly higher (84.1%) in the crayfish tailfan (i.e. uropods) than in the soft abdominal cuticle (38.4%), which is commonly used in prevalence studies. We therefore propose tailfan (uropods and telson) as the preferred tissue for studying A. astaci prevalence in signal crayfish populations. The likelihood of detecting an A. astaci-positive signal crayfish increased significantly with increasing crayfish length. Further, large female crayfish expressed significantly higher PCR-forming units values than large males. In surveys primarily exploring the presence of A. astaci-positive individuals in a population, large females should be selected for molecular analyses. Our study demonstrates that a potent crayfish plague infection reservoir, evidently originating from the illegal human introduction of signal crayfish, has permanently been established in Norway.

  17. Prevalence of the pathogen Aphanomyces astaci in freshwater crayfish populations in Croatia.

    PubMed

    Maguire, Ivana; Jelić, Mišel; Klobučar, Goran; Delpy, Mylène; Delaunay, Carine; Grandjean, Frederic

    2016-02-11

    The Oomycete Aphanomyces astaci is an obligate crayfish parasite that co-evolved with American crayfish species, and they therefore generally live in a balanced relationship. On the contrary, European native crayfish are highly susceptible to A. astaci, and infestation with it causes development of the lethal disease termed crayfish plague. Until now, 5 A. astaci strains have been described from the freshwater crayfish present in Europe. In this study we aimed to investigate the occurrence of the pathogen A. astaci in Croatian native and non-native crayfish populations, as well as to genotype established strains using microsatellite markers and obtain information on the pathogen's epidemiology. Our results showed that the pathogen is widespread in both native and non-native crayfish populations. Agent level, when positive, in non-native crayfish was generally low; in native species it was higher. Genotyping from microsatellites proved the presence of the B (Ps) strain in non-native species (Pacifastacus leniusculus), while the A (As) strain was detected from viable native species (Astacus astacus and Austropotamobius torrentium) that are distributed in areas lacking non-native crayfish. The genotype from A. torrentium differed from a typical A (As) by 1 allele. Strain B (Ps) was identified in native Astacus leptodactylus from the population that co-occurs with P. leniuscuslus. Interestingly, in 1 A. leptodactylus population both A (As) and B (Ps) strains were present. PMID:26865234

  18. Prevalence of the pathogen Aphanomyces astaci in freshwater crayfish populations in Croatia.

    PubMed

    Maguire, Ivana; Jelić, Mišel; Klobučar, Goran; Delpy, Mylène; Delaunay, Carine; Grandjean, Frederic

    2016-02-11

    The Oomycete Aphanomyces astaci is an obligate crayfish parasite that co-evolved with American crayfish species, and they therefore generally live in a balanced relationship. On the contrary, European native crayfish are highly susceptible to A. astaci, and infestation with it causes development of the lethal disease termed crayfish plague. Until now, 5 A. astaci strains have been described from the freshwater crayfish present in Europe. In this study we aimed to investigate the occurrence of the pathogen A. astaci in Croatian native and non-native crayfish populations, as well as to genotype established strains using microsatellite markers and obtain information on the pathogen's epidemiology. Our results showed that the pathogen is widespread in both native and non-native crayfish populations. Agent level, when positive, in non-native crayfish was generally low; in native species it was higher. Genotyping from microsatellites proved the presence of the B (Ps) strain in non-native species (Pacifastacus leniusculus), while the A (As) strain was detected from viable native species (Astacus astacus and Austropotamobius torrentium) that are distributed in areas lacking non-native crayfish. The genotype from A. torrentium differed from a typical A (As) by 1 allele. Strain B (Ps) was identified in native Astacus leptodactylus from the population that co-occurs with P. leniuscuslus. Interestingly, in 1 A. leptodactylus population both A (As) and B (Ps) strains were present.

  19. Invasive crayfish and crayfish plague on the move: first detection of the plague agent Aphanomyces astaci in the Romanian Danube.

    PubMed

    Pârvulescu, Lucian; Schrimpf, Anne; Kozubíková, Eva; Cabanillas Resino, Sara; Vrålstad, Trude; Petrusek, Adam; Schulz, Ralf

    2012-02-17

    Native European crayfish, such as Astacus leptodactylus, are threatened, among other factors, by the crayfish plague agent Aphanomyces astaci, dispersed by invasive North American crayfish. Two of these invaders, Pacifastacus leniusculus and Orconectes limosus, have extended their distribution in the River Danube catchment; the latter was detected for the first time in Romania in 2008. We monitored, at monthly intervals for over 2 yr, occurrence of native A. leptodactylus and invasive O. limosus at 6 sites on the Romanian Danube and checked for the invasive species in 4 of its tributaries. Between January 2009 and March 2011, the relative abundances of O. limosus steadily increased with time, while the native A. leptodactylus dramatically decreased in abundance. O. limosus expanded downstream at a rate of ca. 15 km yr-1; in August 2011, it was already present in the upper 105 km of the Romanian Danube. An agent-specific real-time PCR analyses demonstrated the presence of A. astaci DNA in at least 32% of the analysed invasive (n = 71) and 41% of the native (n = 49) crayfish coexisting in the Danube. Furthermore, A. astaci was also detected in A. leptodactylus captured about 70 km downstream of the O. limosus invasion front (at the time of sampling). Assuming a steady rate of expansion, O. limosus may invade the sensitive Danube delta area in the mid-2060s, even without long-distance dispersal. The crayfish plague agent, however, may reach the delta substantially earlier, through dispersal downstream among populations of native crayfish.

  20. Monitoring the spore dynamics of Aphanomyces astaci in the ambient water of latent carrier crayfish.

    PubMed

    Strand, David A; Jussila, Japo; Viljamaa-Dirks, Satu; Kokko, Harri; Makkonen, Jenny; Holst-Jensen, Arne; Viljugrein, Hildegunn; Vrålstad, Trude

    2012-11-01

    The specialized crayfish parasite Aphanomyces astaci causes the devastating crayfish plague in European crayfish. Even though A. astaci sporulation has been thoroughly studied under pure culture conditions, little is known about the sporulation dynamic from its live host. Our purpose was to investigate the A. astaci spore dynamic in its native parasite-host relationship by monitoring the sporulation from carrier crayfish into the ambient water using agent specific qPCR. American signal crayfish (Pacifastacus leniusculus) with known positive carrier status were housed individually and communally in two experimental set-ups using multiple replicates and different temperatures. Water samples were collected weekly, and spore numbers were quantified. We demonstrate here that live latent carrier crayfish continuously released a moderate number of A. astaci spores (~2700 spores per crayfish/week) in the absence of death and moulting events. In contrast, a pronounced sporulation increase was seen already one week prior to death in moribund crayfish, suggesting a crayfish plague-like condition developing in weakened or stressed individuals. Significantly more spores were produced at 18°C compared to 4°C, while a negative correlation was detected between spore numbers and temperatures rising from 17 to 23°C. This study is the first attempt to quantify the spore release from carrier crayfish on the basis of qPCR applied on water samples, and demonstrate that the approach successfully unravel A. astaci sporulation patterns. The results emphasize that carrier crayfish pose a constant infection risk to highly susceptible crayfish species regardless of crayfish life cycle state.

  1. Passive samplers accurately predict PAH levels in resident crayfish.

    PubMed

    Paulik, L Blair; Smith, Brian W; Bergmann, Alan J; Sower, Greg J; Forsberg, Norman D; Teeguarden, Justin G; Anderson, Kim A

    2016-02-15

    Contamination of resident aquatic organisms is a major concern for environmental risk assessors. However, collecting organisms to estimate risk is often prohibitively time and resource-intensive. Passive sampling accurately estimates resident organism contamination, and it saves time and resources. This study used low density polyethylene (LDPE) passive water samplers to predict polycyclic aromatic hydrocarbon (PAH) levels in signal crayfish, Pacifastacus leniusculus. Resident crayfish were collected at 5 sites within and outside of the Portland Harbor Superfund Megasite (PHSM) in the Willamette River in Portland, Oregon. LDPE deployment was spatially and temporally paired with crayfish collection. Crayfish visceral and tail tissue, as well as water-deployed LDPE, were extracted and analyzed for 62 PAHs using GC-MS/MS. Freely-dissolved concentrations (Cfree) of PAHs in water were calculated from concentrations in LDPE. Carcinogenic risks were estimated for all crayfish tissues, using benzo[a]pyrene equivalent concentrations (BaPeq). ∑PAH were 5-20 times higher in viscera than in tails, and ∑BaPeq were 6-70 times higher in viscera than in tails. Eating only tail tissue of crayfish would therefore significantly reduce carcinogenic risk compared to also eating viscera. Additionally, PAH levels in crayfish were compared to levels in crayfish collected 10 years earlier. PAH levels in crayfish were higher upriver of the PHSM and unchanged within the PHSM after the 10-year period. Finally, a linear regression model predicted levels of 34 PAHs in crayfish viscera with an associated R-squared value of 0.52 (and a correlation coefficient of 0.72), using only the Cfree PAHs in water. On average, the model predicted PAH concentrations in crayfish tissue within a factor of 2.4 ± 1.8 of measured concentrations. This affirms that passive water sampling accurately estimates PAH contamination in crayfish. Furthermore, the strong predictive ability of this simple model suggests

  2. Survey of the crayfish plague pathogen presence in the Netherlands reveals a new Aphanomyces astaci carrier.

    PubMed

    Tilmans, M; Mrugała, A; Svoboda, J; Engelsma, M Y; Petie, M; Soes, D M; Nutbeam-Tuffs, S; Oidtmann, B; Roessink, I; Petrusek, A

    2014-07-01

    North American crayfish species as hosts for the crayfish plague pathogen Aphanomyces astaci contribute to the decline of native European crayfish populations. At least six American crayfish species have been reported in the Netherlands but the presence of this pathogenic oomycete with substantial conservational impact has not yet been confirmed in the country. We evaluated A. astaci prevalence in Dutch populations of six alien crustaceans using species-specific quantitative PCR. These included three confirmed crayfish carriers (Orconectes limosus, Pacifastacus leniusculus, Procambarus clarkii), two recently introduced but yet unstudied crayfish (Orconectes cf. virilis, Procambarus cf. acutus), and a catadromous crab Eriocheir sinensis. Moderate levels of infection were observed in some populations of O. limosus and P. leniusculus. Positive results were also obtained for E. sinensis and two Dutch populations of O. cf. virilis. English population of the latter species was also found infected, confirming this taxon as another A. astaci carrier in European waters. In contrast, Dutch P. clarkii seem only sporadically infected, and the pathogen was not yet detected in P. cf. acutus. Our study is the first confirmation of crayfish plague infections in the Netherlands and demonstrates substantial variation in A. astaci prevalence among potential hosts within a single region, a pattern possibly linked to their introduction history and coexistence.

  3. Feeding response by northern squawfish to a hatchery release of juvenile salmonids in the Clearwater River, Idaho

    USGS Publications Warehouse

    Shively, R.S.; Poe, T.P.; Sauter, S.T.

    1996-01-01

    We collected gut contents from northern squawfish Ptychocheilus oregonensis captured in the Clearwater River, Idaho, 0–6 km from its confluence with the Snake River, following the release of 1.1 million yearling chinook salmon Oncorhynchus tshawytscha from the Dworshak National Fish Hatchery. Before the hatchery release, northern squawfish gut contents (by weight) in the study area were 38% crayfish Pacifastacus spp., 26% insects, 19% nonsalmonid fish, and 16% wheat kernels Triticum spp. Juvenile salmonids constituted 54% of gut contents about 24 h after the hatchery release, 78% after 5 d, and 86% after 7 d. The mean number of salmonids per gut (1.2) after release was higher than typically seen in guts from northern squawfish collected in mid-reservoir areas away from hydroelectric dams on the Snake and Columbia rivers. Length-frequency distributions of juvenile salmonids eaten and those captured in a scoop trap 4 km upstream of the study area indicated that northern squawfish were selectively feeding on the smaller individuals. We attribute the high rates of predation in the study area to the artificially high density of juvenile salmonids resulting from the hatchery release and to the physical characteristics of the study area in which the river changed from free flowing to impounded. Our results suggest that northern squawfish can quickly exploit hatchery releases of juvenile salmonids away from release sites in the Columbia River basin.

  4. Melanization and pathogenicity in the insect, Tenebrio molitor, and the crustacean, Pacifastacus leniusculus, by Aeromonas hydrophila AH-3.

    PubMed

    Noonin, Chadanat; Jiravanichpaisal, Pikul; Söderhäll, Irene; Merino, Susana; Tomás, Juan M; Söderhäll, Kenneth

    2010-01-01

    Aeromonas hydrophila is the most common Aeromonas species causing infections in human and other animals such as amphibians, reptiles, fish and crustaceans. Pathogenesis of Aeromonas species have been reported to be associated with virulence factors such as lipopolysaccharides (LPS), bacterial toxins, bacterial secretion systems, flagella, and other surface molecules. Several mutant strains of A. hydrophila AH-3 were initially used to study their virulence in two animal species, Pacifastacus leniusculus (crayfish) and Tenebrio molitor larvae (mealworm). The AH-3 strains used in this study have mutations in genes involving the synthesis of flagella, LPS structures, secretion systems, and some other factors, which have been reported to be involved in A. hydrophila pathogenicity. Our study shows that the LPS (O-antigen and external core) is the most determinant A. hydrophila AH-3 virulence factor in both animals. Furthermore, we studied the immune responses of these hosts to infection of virulent or non-virulent strains of A. hydrophila AH-3. The AH-3 wild type (WT) containing the complete LPS core is highly virulent and this bacterium strongly stimulated the prophenoloxidase activating system resulting in melanization in both crayfish and mealworm. In contrast, the ΔwaaE mutant which has LPS without O-antigen and external core was non-virulent and lost ability to stimulate this system and melanization in these two animals. The high phenoloxidase activity found in WT infected crayfish appears to result from a low expression of pacifastin, a prophenoloxidase activating enzyme inhibitor, and this gene expression was not changed in the ΔwaaE mutant infected animal and consequently phenoloxidase activity was not altered as compared to non-infected animals. Therefore we show that the virulence factors of A. hydrophila are the same regardless whether an insect or a crustacean is infected and the O-antigen and external core is essential for activation of the proPO system

  5. Aphanomyces astaci in wild crayfish populations in Slovenia: first report of persistent infection in a stone crayfish Austropotamobius torrentium population.

    PubMed

    Kusar, Darja; Vrezec, Al; Ocepek, Matja; Jencic, Vlasta

    2013-03-26

    All 5 crayfish species inhabiting Slovenian freshwaters, of which 3 are indigenous crayfish species (ICS: Astacus astacus, Austropotamobius pallipes, and A. torrentium) and 2 are non-indigenous (NICS: Pacifastacus leniusculus and Cherax quadricarinatus), were inspected for the presence of Aphanomyces astaci, the causative agent of crayfish plague. Wild crayfish populations showing no clinical signs of infection were inspected using A. astaci-specific real-time PCR. In addition, a conventional PCR assay was employed and confirmative sequencing was performed. Out of 88 analyzed crayfish, 15/27 (55.6%) specimens of A. torrentium from Borovnišcˇ%%KERN_ERR%%ica Brook and 4/35 (11.4%) of P. leniusculus from the Mura River tested positive, showing low to moderate levels of infection (agent levels A1-A4 and A1-A3, respectively). Results revealed the presence of A. astaci not only in the resistant NICS but also in ICS, since the infected population of A. torrentium presumably had no contact with the NICS carrier and appeared to sustain A. astaci infection in the 2 sampling years. Although the A. astaci genotype has not yet been identified, a connection between the latent infection in ICS and a Group A strain of A. astaci, co-evolving with A. torrentium since its first introduction to Slovenia, is suggested as the most plausible conclusion. This is the first reported population of the genus Austropotamobius with persistent infection, in addition to the already known populations of the genus Astacus. Findings of the presumed co-evolution of A. astaci and ICS hosts open new perspectives, necessitating additional studies on the presence of A. astaci genotypes in the persistently infected ICS populations.

  6. Phylogeographic insights into the invasion history and secondary spread of the signal crayfish in Japan.

    PubMed

    Usio, Nisikawa; Azuma, Noriko; Larson, Eric R; Abbott, Cathryn L; Olden, Julian D; Akanuma, Hiromi; Takamura, Kenzi; Takamura, Noriko

    2016-08-01

    Successful invasion by nonindigenous species is often attributed to high propagule pressure, yet some foreign species become widespread despite showing reduced genetic variation due to founder effects. The signal crayfish (Pacifastacus leniusculus) is one such example, where rapid spread across Japan in recent decades is believed to be the result of only three founding populations. To infer the history and explore the success of this remarkable crayfish invasion, we combined detailed phylogeographical and morphological analyses conducted in both the introduced and native ranges. We sequenced 16S mitochondrial DNA of signal crayfish from across the introduced range in Japan (537 samples, 20 sites) and the native range in western North America (700 samples, 50 sites). Because chela size is often related to aggressive behavior in crayfish, and hence, their invasion success, we also measured chela size of a subset of specimens in both introduced and native ranges. Genetic diversity of introduced signal crayfish populations was as high as that of the dominant phylogeographic group in the native range, suggesting high propagule pressure during invasion. More recently established crayfish populations in Japan that originated through secondary spread from one of the founding populations exhibit reduced genetic diversity relative to older populations, probably as a result of founder effects. However, these newer populations also show larger chela size, consistent with expectations of rapid adaptations or phenotypic responses during the invasion process. Introduced signal crayfish populations in Japan originate from multiple source populations from a wide geographic range in the native range of western North America. A combination of high genetic diversity, especially for older populations in the invasive range, and rapid adaptation to colonization, manifested as larger chela in recent invasions, likely contribute to invasion success of signal crayfish in Japan. PMID

  7. Biotic drivers of fluvial sediment transport: Aggregate effects of sediment mobilisation by crayfish on catchment-scale sediment yield

    NASA Astrophysics Data System (ADS)

    Rice, Stephen; Mathers, Kate; Reeds, Jake; Extence, Chris

    2015-04-01

    Small but prolific organisms may be significant zoogeomorphic agents that make cumulative contributions to the large-scale terrestrial sediment cascade in, as yet, unknown and unquantified ways. One such organism is the signal crayfish (Pacifastacus leniusculus), which has invaded many European rivers. The geographical extent and abundance of this animal ensure innumerable local, small-scale interactions with the fluvial sediment system that have the potential to yield a substantial effect when aggregated across larger spatial and temporal scales. Here we estimate, for the first time, the proportion of the total annual sediment yield associated with crayfish activity in an infested river and examine the variability in crayfish-driven sediment flux integrated across daily, monthly and seasonal time scales. We focused on one of several mechanisms by which crayfish activities affect sediment dynamics: the mobilisation of fine sediments by foraging, fighting and burrowing under hydraulic conditions that are otherwise insufficient to entrain sediment. On the Brampton Branch of the River Nene, UK, a 12-month record of suspended sediment concentration (derived from a calibration of turbidity data against measured SSC) allowed calculation of sediment fluxes and integrated sediment loads at ten-minute intervals. Concurrent measurements of water depth and crayfish movements (using PIT tagging) confirmed that night-time crayfish activity was often associated with increased sediment fluxes in the absence of any change in hydraulic conditions. Sediment loads calculated for these periods of crayfish activity were compared with total loads to estimate the contribution made to sediment mobilisation by crayfish. Crayfish-induced fluxes were most significant during summer low-flows, becoming less important during winter when the crayfish were inactive and competent high flows dominated sediment transport. Nevertheless, the seasonal cumulative effect of crayfish was substantial and

  8. Crazy about Crayfish

    ERIC Educational Resources Information Center

    Endreny, Anna

    2006-01-01

    Crayfish, also known as "crawfish" or "crawdads," are easy to keep in the classroom, and with patience and luck, students will observe the complete life cycle of the crayfish. They will also learn about aquatic animals and habitats and get to conduct inquiry experiments about animal behavior. This article describes how a third-grade teacher used…

  9. Crayfish for Research

    ERIC Educational Resources Information Center

    Poulos, C. Jean

    1977-01-01

    This article describes how Robert LeBleu's interest in aquatic life developed and that today he owns a large hydroculture operation supplying research crayfish nationwide. Suggested laboratory experiments with crayfish are described, as well as information on additional studies, equipment needs, and tours of the hatchery. (MA)

  10. Differences in aggression, activity and boldness between native and introduced populations of an invasive crayfish

    USGS Publications Warehouse

    Pintor, L.M.; Sih, A.; Bauer, M.L.

    2008-01-01

    Aggressiveness, along with foraging voracity and boldness, are key behavioral mechanisms underlying the competitive displacement and invasion success of exotic species. However, do aggressiveness, voracity and boldness of the invader depend on the presence of an ecologically similar native competitor in the invaded community? We conducted four behavioral assays to compare aggression, foraging voracity, threat response and boldness to forage under predation risk of multiple populations of exotic signal crayfish Pacifastacus leniusculus across its native and invaded range with and without a native congener, the Shasta crayfish P. fortis. We predicted that signal crayfish from the invaded range and sympatric with a native congener (IRS) should be more aggressive to outcompete a close competitor than populations from the native range (NR) or invaded range and allopatric to a native congener (IRA). Furthermore, we predicted that IRS populations of signal crayfish should be more voracious, but less bold to forage under predation risk since native predators and prey likely possess appropriate behavioral responses to the invader. Contrary to our predictions, results indicated that IRA signal crayfish were more aggressive towards conspecifics and more voracious and active foragers, yet also bolder to forage under predation risk in comparison to NR and IRS populations, which did not differ in behavior. Higher aggression/voracity/ boldness was positively correlated with prey consumption rates, and hence potential impacts on prey. We suggest that the positive correlations between aggression/voracity/boldness are the result of an overall aggression syndrome. Results of stream surveys indicated that IRA streams have significantly lower prey biomass than in IRS streams, which may drive invading signal crayfish to be more aggressive/voracious/bold to acquire resources to establish a population. ?? 2008 The Authors.

  11. Tag retention, growth, and survival of red swamp crayfish marked with a visible implant tag

    USGS Publications Warehouse

    Isely, J.J.; Stockett, P.E.

    2001-01-01

    Eighty juvenile (means: 42.4 mm total length, 1.6 g) red swamp crayfish Procambarus clarkii were implanted with sequentially numbered visible implant tags and held in the laboratory. Tags were injected transversely into the musculature just beneath the exoskeleton of the third abdominal segment from the cephalothorax; tags were visible upon inspection. An additional 20 crayfish were left untagged and served as controls. After 150 d, tag retention was 80% and all tags were readable. No tagged crayfish died during the study, and no differences in total length or weight were detected between tagged and control crayfish. All individuals molted at least three times during the 150-d study, and some individuals molted up to six times, suggesting that most tags would be permanently retained. The readability in the field without specialized equipment makes the visible implant tag ideal for studies of crayfish ecology, management, and culture.

  12. Predation of Biomphalaria and non-target molluscs by the crayfish Procambarus clarkii: implications for the biological control of schistosomiasis.

    PubMed

    Hofkin, B V; Hofinger, D M; Koech, D K; Loker, E S

    1992-12-01

    The North American crayfish Procambarus clarkii was examined under laboratory conditions for its ability to prey on Biomphalaria pfeifferi and B. glabrata, molluscan intermediate hosts of human schistosomiasis, and other, non-target gastropod species. Both male and female adult crayfish significantly reduced survival of neonate snails, even though alternative animal and plant foods were both available. In subsequent experiments, no differences in snail consumption were detected, for either adult or juvenile crayfish, in the presence or absence of a plant food alternative. Both adult and juvenile crayfish were able to consume small (2.5 mm) and large (17.5 mm) B. glabrata, suggesting that no size refuge from predation exists. Both adult and juvenile crayfish consumed Biomphalaria egg masses, although this consumption was significantly greater for juveniles. Procambarus clarkii adults were unable to consume substantial numbers of the relatively thick-shelled prosobranch snails Pila ovata and Lanistes carinatus. Crayfish did consume a third prosobranch, Melanoides tuberculata, and the pulmonate snail Physa acuta, but at a lower rate relative to consumption of Biomphalaria. Physa acuta, itself of North American origin, responded to the presence of crayfish by rapidly leaving the water and thereby avoided predation. Implications of these results for the biological control of schistosome-transmitting snails in East Africa are discussed.

  13. Tag retention, growth, and survival of red swamp crayfish Procambarus clarkii marked with coded wire tags

    USGS Publications Warehouse

    Isely, J.J.; Eversole, A.G.

    1998-01-01

    Juvenile red swamp crayfish (or crawfish), Procambarus clarkii (20-41 mm in total length) were collected from a crayfish culture pond by dipnetting and tagged with sequentially numbered, standard length, binary-coded wire tags. Four replicates of 50 crayfish were impaled perpendicular to the long axis of the abdomen with a fixed needle. Tags were injected transversely into the ventral surface of the first or second abdominal segment and were imbedded in the musculature just beneath the abdominal sternum. Tags were visible upon inspection. Additionally, two replicates of 50 crayfish were not tagged and were used as controls. Growth, survival, and tag retention were evaluated after 7 d in individual containers, after 100 d in aquaria, and after 200 d in field cages. Tag retention during each sample period was 100%, and average mortality of tagged crayfish within 7 d of tagging was 1%. Mortality during the remainder of the study was high (75-91%) but was similar between treatment and control samples. Most of the deaths were probably due to cannibalism. Average total length increased threefold during the course of the study, and crayfish reached maturity. Because crayfish were mature by the end of the study, we concluded that the coded wire tag was retained through the life history of the crayfish.

  14. Habitat and co-occurrence of native and invasive crayfish in the Pacific Northwest, USA

    USGS Publications Warehouse

    Pearl, Christopher A.; Adams, Michael J.; McCreary, Brome

    2013-01-01

    Biological invasions can have dramatic effects on freshwater ecosystems and introduced crayfish can be particularly impacting. We document crayfish distribution in three large hydrographic basins (Rogue, Umpqua, Willamette/Columbia) in the Pacific Northwest USA. We used occupancy analyses to investigate habitat relationships and evidence for displacement of native Pacifastacus leniusculus (Dana, 1852) by two invaders. We found invasive Procambarus clarkii (Girard, 1852), in 51 of 283 sites and in all three hydrographic basins. We found invasive Orconectes n. neglectus (Faxon, 1885) at 68% of sites in the Rogue basin and provide first documentation of their broad distribution in the Umpqua basin. We found P. clarkii in both lentic and lotic habitats, and it was positively associated with manmade sites. P. leniusculus was positively associated with lotic habitats and negatively related to manmade sites. In the Rogue and Umpqua basins, O. n. neglectus and P. leniusculus were similar in their habitat associations. We did not find a negative relationship in site occupancy between O. n. neglectus and P. leniusculus. Our data suggest that P. clarkii has potential to locally displace P. leniusculus. There is still time for preventive measures to limit the spread of the invasive crayfish in this region.

  15. Laboratory agonistic interactions demonstrate failure of an introduced crayfish to dominate two imperiled endemic crayfishes

    USGS Publications Warehouse

    Rahm, E.J.; Griffith, S.A.; Noltie, Douglas B.; DiStefano, R.J.

    2005-01-01

    Following its introduction into the St. Francis River drainage, Missouri, U.S.A., the woodland crayfish, Orconectes hylas has expanded its range there; simultaneously populations of two imperiled endemic species, the Big Creek crayfish, O. peruncus, and the St. Francis River crayfish, O. quadruncus have declined therein. In seeking a basis for this decline, our study objective was to test whether the outcome of aggressive inter-specific interactions would favor O. hylas. We studied agonistic encounters between size-matched pairs of same-sex individuals of the introduced and the endemic species in a laboratory setting, first with juveniles and then with adults. Within each life stage, we conducted four sets of laboratory experiments, with approximately 20 trials in each set: (1) O. hylas males versus O. peruncus males, (2) O. hylas males versus O. quadruncus males, (3) O. hylas females versus O. peruncus females, and (4) O. hylas females versus O. quadruncus females. In addition, these same four experiment sets were repeated using larger adult O. hylas crayfish matched with smaller-sized adult endemics, mimicking the mismatch in adult sizes that occurs in the wild. Within each experiment, every trial was analysed to quantify the frequency of occurrence of three initiation behaviors and to determine the overall outcome of the trial. Results did not show O. hylas (juveniles or adults) to be behaviorally dominant over either endemic species. Orconectes hylas displayed the majority of one of the initiation behaviors significantly more often than did the endemic species in only two of the twelve experiments. Because direct aggressive interaction was not demonstrated to be the mechanism whereby O. peruncus and O. quadruncus are being replaced by O. hylas, other life history and ecological factors will require investigation. ?? Koninklijke Brill NV, 2005.

  16. Habitat use and growth of the western painted crayfish Orconectes palmeri longimanus

    USGS Publications Warehouse

    Dyer, Joseph J.; Mouser, Joshua; Brewer, Shannon K.

    2016-01-01

    Identifying ontogenetic shifts in habitat use by aquatic organisms is necessary for improving conservation strategies; however, our ability to designate life stages based on surrogate metrics (i.e., length) is questionable without validation. This study identified growth patterns of age-0 western painted crayfish Orconectes palmeri longimanus (Faxon, 1898) reared in the laboratory, provided support for field-based designations of age-0 lengths, and identified microhabitat factors important to adult and juvenile presence from field collections. Two growth periods of a laboratory crayfish population were described using a broken line model: a rapid, early-growth period (weeks 2-20, slope = 0.81 ± 0.03SE), and a slower, late-growth period (weeks 22-50, slope = 0.13 ± 0.03SE). A smoothed curve was generated to represent the size distribution of juveniles from our laboratory population to determine the probability that an age-0 crayfish from our laboratory population had a carapace length (CL) similar to that found in previous field studies using onset of maturity (22.4 mm CL). We determined that the probability of the age-0 crayfish in our summer laboratory population exceeding 22.4 mm CL was 0.06. The threshold between the lower 0.95 and upper 0.05 probabilities was 22.9 mm CL, confirming previous field observations of onset at maturity. We used this threshold to identify juveniles and adults from our field collections, and found that both life stages were positively associated with coarse substrate and negatively associated with water depth. Adults, however, were negatively related to gravel, whereas juveniles showed a positive relationship. This result is reflective of the relationship between crayfish body size and refuge use within the interstitial spaces of substrates, whereby adult crayfish are unable to seek refuge in the small interstitial spaces of gravel.

  17. The significance of droughts for hyporheic dwellers: evidence from freshwater crayfish

    PubMed Central

    Kouba, Antonín; Tíkal, Jan; Císař, Petr; Veselý, Lukáš; Fořt, Martin; Příborský, Josef; Patoka, Jiří; Buřič, Miloš

    2016-01-01

    Freshwater biodiversity is globally threatened by various factors while severe weather events like long-term droughts may be substantially devastating. In order to remain in contact with the water or stay in a sufficiently humid environment at drying localities, the ability to withstand desiccation by dwelling in the hyporheic zone, particularly through vertical burrowing is crucial. We assessed the ability of three European native and five non-native crayfish as models to survive and construct vertical burrows in a humid sandy-clayey substrate under a simulated one-week drought. Three native species (Astacus astacus, A. leptodactylus, and Austropotamobius torrentium) suffered extensive mortalities. Survival of non-native species was substantially higher while all specimens of Cherax destructor and Procambarus clarkii survived. The native species and Pacifastacus leniusculus exhibited no ability to construct vertical burrows. Procambarus fallax f. virginalis and P. clarkii constructed bigger and deeper burrows than C. destructor and Orconectes limosus. In the context of predicted weather fluctuations, the ability to withstand desiccation through constructing vertical burrows into the hyporheic zone under drought conditions might play a significant role in the success of particular crayfish species, as well as a wide range of further hyporheic-dwelling aquatic organisms in general. PMID:27225308

  18. The significance of droughts for hyporheic dwellers: evidence from freshwater crayfish

    NASA Astrophysics Data System (ADS)

    Kouba, Antonín; Tíkal, Jan; Císař, Petr; Veselý, Lukáš; Fořt, Martin; Příborský, Josef; Patoka, Jiří; Buřič, Miloš

    2016-05-01

    Freshwater biodiversity is globally threatened by various factors while severe weather events like long-term droughts may be substantially devastating. In order to remain in contact with the water or stay in a sufficiently humid environment at drying localities, the ability to withstand desiccation by dwelling in the hyporheic zone, particularly through vertical burrowing is crucial. We assessed the ability of three European native and five non-native crayfish as models to survive and construct vertical burrows in a humid sandy-clayey substrate under a simulated one-week drought. Three native species (Astacus astacus, A. leptodactylus, and Austropotamobius torrentium) suffered extensive mortalities. Survival of non-native species was substantially higher while all specimens of Cherax destructor and Procambarus clarkii survived. The native species and Pacifastacus leniusculus exhibited no ability to construct vertical burrows. Procambarus fallax f. virginalis and P. clarkii constructed bigger and deeper burrows than C. destructor and Orconectes limosus. In the context of predicted weather fluctuations, the ability to withstand desiccation through constructing vertical burrows into the hyporheic zone under drought conditions might play a significant role in the success of particular crayfish species, as well as a wide range of further hyporheic-dwelling aquatic organisms in general.

  19. The significance of droughts for hyporheic dwellers: evidence from freshwater crayfish.

    PubMed

    Kouba, Antonín; Tíkal, Jan; Císař, Petr; Veselý, Lukáš; Fořt, Martin; Příborský, Josef; Patoka, Jiří; Buřič, Miloš

    2016-01-01

    Freshwater biodiversity is globally threatened by various factors while severe weather events like long-term droughts may be substantially devastating. In order to remain in contact with the water or stay in a sufficiently humid environment at drying localities, the ability to withstand desiccation by dwelling in the hyporheic zone, particularly through vertical burrowing is crucial. We assessed the ability of three European native and five non-native crayfish as models to survive and construct vertical burrows in a humid sandy-clayey substrate under a simulated one-week drought. Three native species (Astacus astacus, A. leptodactylus, and Austropotamobius torrentium) suffered extensive mortalities. Survival of non-native species was substantially higher while all specimens of Cherax destructor and Procambarus clarkii survived. The native species and Pacifastacus leniusculus exhibited no ability to construct vertical burrows. Procambarus fallax f. virginalis and P. clarkii constructed bigger and deeper burrows than C. destructor and Orconectes limosus. In the context of predicted weather fluctuations, the ability to withstand desiccation through constructing vertical burrows into the hyporheic zone under drought conditions might play a significant role in the success of particular crayfish species, as well as a wide range of further hyporheic-dwelling aquatic organisms in general. PMID:27225308

  20. The thermal tolerance of crayfish could be estimated from respiratory electron transport system activity.

    PubMed

    Simčič, Tatjana; Pajk, Franja; Jaklič, Martina; Brancelj, Anton; Vrezec, Al

    2014-04-01

    Whether electron transport system (ETS) activity could be used as an estimator of crayfish thermal tolerance has been investigated experimentally. Food consumption rate, respiration rates in the air and water, the difference between energy consumption and respiration costs at a given temperature ('potential growth scope', PGS), and ETS activity of Orconectes limosus and Pacifastacus leniusculus were determined over a temperature range of 5-30°C. All concerned parameters were found to be temperature dependent. The significant correlation between ETS activity and PGS indicates that they respond similarly to temperature change. The regression analysis of ETS activity as an estimator of thermal tolerance at the mitochondrial level and PGS as an indicator of thermal tolerance at the organismic level showed the shift of optimum temperature ranges of ETS activity to the right for 2° in O. limosus and for 3° in P. leniusculus. Thus, lower estimated temperature optima and temperatures of optimum ranges of PGS compared to ETS activity could indicate higher thermal sensitivity at the organismic level than at a lower level of complexity (i.e. at the mitochondrial level). The response of ETS activity to temperature change, especially at lower and higher temperatures, indicates differences in the characteristics of the ETSs in O. limosus and P. leniusculus. O. limosus is less sensitive to high temperature. The significant correlation between PGS and ETS activity supports our assumption that ETS activity could be used for the rapid estimation of thermal tolerance in crayfish species. PMID:24679968

  1. Nitrite toxicity to the crayfish Procambarus clarkii

    SciTech Connect

    Gutzmer, M.P.; Tomasso, J.R.

    1985-03-01

    The purpose of this study was to determine the effects of acute nitrite exposure to the crayfish Procambarus clarkii (Decapoda). Specific objectives of this study included (1) determining the 24-, 48-, 72- and 96-h LC-50's of nitrite to crayfish of different weights and genders in freshwater, (2) determining the LC-50's of nitrite to crayfish in water with elevated chloride concentrations, and (3), in order to gain insight into the mechanisms of nitrite toxicity in crayfish, determining hemolymph nitrite concentrations in crayfish exposed to nitrite in freshwater and water with elevated chloride concentrations.

  2. 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

  3. Recording behavioral responses to reflection in crayfish.

    PubMed

    Mercier, A Joffre; May, Holly Y

    2010-01-01

    Social behavior depends on sensory input from the visual, mechanical and olfactory systems. One important issue concerns the relative roles of each sensory modality in guiding behavior. The role of visual inputs has been examined by isolating visual stimuli from mechanical and chemosensory stimuli. In some studies (Bruski & Dunham, 1987: Delgado-Morales et al., 2004) visual inputs have been removed with blindfolds or low light intensity, and effects of remaining sensory modalities have been elucidated. An alternative approach is to study the effects of visual inputs in the absence of any appropriate mechanical and chemosensory cues. This approach aims to identify the exclusive role of visual inputs. We have used two methods to provide visual stimuli to crayfish without providing chemical and mechanical cues. In one method, crayfish are videotaped in an aquarium where half of the walls are covered in mirrors to provide a reflective environment, and the other half are covered in a non-reflective (matte finish) plastic. This gives the crayfish a choice between reflective and non-reflective environments. The reflective environment provides visual cues in the form of reflected images of the crayfish as it moves throughout half of the tank; these visual cues are missing from the non-reflective half of the tank. An alternative method is to videotape the behavior of crayfish in an aquarium separated by a smaller chamber at each end, with a crayfish in one small chamber providing visual cues and an inert object in the opposite small chamber providing visual input from a non-moving, non-crayfish source. Our published results indicate that responses of crayfish to the reflective environment depend on socialization and dominance rank. Socialized crayfish spent more time in the reflective environment and exhibited certain behaviors more frequently there than in the non-reflective environment; isolated crayfish showed no such differences. Crayfish that were housed in same

  4. Effects of Different Social and Environmental Conditions on Established Dominance Relationships in Crayfish.

    PubMed

    Herberholz, Jens; Swierzbinski, Matthew E; Birke, Juliane M

    2016-04-01

    Like most social animals, crayfish readily form dominance relationships and linear social hierarchies when competing for limited resources. Competition often entails dyadic aggressive interactions, from which one animal emerges as the dominant and one as the subordinate. Once dominance relationships are formed, they typically remain stable for extended periods of time; thus, access to future resources is divided unequally among conspecifics. We previously showed that firmly established dominance relationships in juvenile crayfish can be disrupted by briefly adding a larger conspecific to the original pair. This finding suggested that the stability of social relationships in crayfish was highly context-dependent and more transient than previously assumed. We now report results that further identify the mechanisms underlying the destabilization of crayfish dominance relationships. We found that rank orders remained stable when conspecifics of smaller or equal size were added to the original pair, suggesting that both dominant and subordinate must be defeated by a larger crayfish in order to destabilize dominance relationships. We also found that dominance relationships remained stable when both members of the original pair were defeated by larger conspecifics in the absence of their original opponent. This showed that dominance relationships are not destabilized unless both animals experience defeat together. Lastly, we found that dominance relationships of pairs were successfully disrupted by larger intruders, although with reduced magnitude, after all chemical cues associated with earlier agonistic experiences were eliminated. These findings provide important new insights into the contextual features that regulate the stability of social dominance relationships in crayfish and probably in other species as well. PMID:27132137

  5. Invasion biology in non-free-living species: interactions between abiotic (climatic) and biotic (host availability) factors in geographical space in crayfish commensals (Ostracoda, Entocytheridae).

    PubMed

    Mestre, Alexandre; Aguilar-Alberola, Josep A; Baldry, David; Balkis, Husamettin; Ellis, Adam; Gil-Delgado, Jose A; Grabow, Karsten; Klobučar, Göran; Kouba, Antonín; Maguire, Ivana; Martens, Andreas; Mülayim, Ayşegül; Rueda, Juan; Scharf, Burkhard; Soes, Menno; S Monrós, Juan; Mesquita-Joanes, Francesc

    2013-12-01

    In invasion processes, both abiotic and biotic factors are considered essential, but the latter are usually disregarded when modeling the potential spread of exotic species. In the framework of set theory, interactions between biotic (B), abiotic (A), and movement-related (M) factors in the geographical space can be hypothesized with BAM diagrams and tested using ecological niche models (ENMs) to estimate A and B areas. The main aim of our survey was to evaluate the interactions between abiotic (climatic) and biotic (host availability) factors in geographical space for exotic symbionts (i.e., non-free-living species), using ENM techniques combined with a BAM framework and using exotic Entocytheridae (Ostracoda) found in Europe as model organisms. We carried out an extensive survey to evaluate the distribution of entocytherids hosted by crayfish in Europe by checking 94 European localities and 12 crayfish species. Both exotic entocytherid species found, Ankylocythere sinuosa and Uncinocythere occidentalis, were widely distributed in W Europe living on the exotic crayfish species Procambarus clarkii and Pacifastacus leniusculus, respectively. No entocytherids were observed in the remaining crayfish species. The suitable area for A. sinuosa was mainly restricted by its own limitations to minimum temperatures in W and N Europe and precipitation seasonality in circum-Mediterranean areas. Uncinocythere occidentalis was mostly restricted by host availability in circum-Mediterranean regions due to limitations of P. leniusculus to higher precipitation seasonality and maximum temperatures. The combination of ENMs with set theory allows studying the invasive biology of symbionts and provides clues about biogeographic barriers due to abiotic or biotic factors limiting the expansion of the symbiont in different regions of the invasive range. The relative importance of abiotic and biotic factors on geographical space can then be assessed and applied in conservation plans. This

  6. Copper accumulation in the crayfish (Orconectes rusticus)

    SciTech Connect

    Evans, M.L.

    1980-06-01

    The purpose of this study was to determine whether or not the crayfish, O. rusticus could fulfill Nehring's (1976) criteria for a good biological monitor of heavy metal pollution. Since there is some evidence that the cupric ion is the most toxic form of aqueous copper, crayfish-accumulated copper was compared to both total and cupric copper in the culture water.

  7. Ontogeny of the antennal glands in the crayfish Astacus leptodactylus (Crustacea, Decapoda): immunolocalization of Na+,K+-ATPase.

    PubMed

    Khodabandeh, S; Kutnik, M; Aujoulat, F; Charmantier, G; Charmantier-Daures, M

    2005-01-01

    The involvement of the antennal urinary glands in the ontogeny of osmoregulatory functions was investigated during the development of Astacus leptodactylus by measurements of hemolymph and urine osmolality in juvenile and adult crayfish and by the immunodetection of the enzyme Na+,K+-ATPase. In stage II juveniles, 1-year-old juveniles, and adults, all of which were maintained in freshwater, urine was significantly hypotonic to hemolymph. In adults, chloride and sodium concentrations were much lower in urine than in hemolymph. During embryonic development, Na+,K+-ATPase was detected by immunocytochemistry in ionocytes lining the tubule and the bladder, at an eye index (EI) of 220-250 microm, and in the labyrinth, at EI 350 microm. In all regions, immunofluorescence was mainly located at the basolateral side of the cells. No immunofluorescence was detected at any stage in the coelomosac. In late embryonic stages (EI 410-440 microm), in stage I juveniles, and in adults, strong positive immunofluorescence was found from the labyrinth up to and including the bladder. These results show that, as early as hatching, juvenile crayfish are able to produce dilute urine hypotonic to hemolymph. This ability originates from the presence of Na+,K+-ATPase in ion-transporting cells located in the labyrinth, the tubule, and the bladder of the antennal glands and constitutes one of the main adaptations of crayfish to freshwater.

  8. Invasive crayfish in the Pacific Northwest

    USGS Publications Warehouse

    Pearl, Christopher A.; McCreary, Brome; Adams, Michael

    2011-01-01

    Invasive species directly threaten freshwater biodiversity, particularly in regions of high aquatic richness like the Pacific Northwest (PNW). Crayfish are among the most impactful of aquatic invasive species. Invasive crayfish are considered ecosystem engineers due to their ability to alter basic wetland properties, such as reducing vegetation and bank integrity and increasing turbidity. In areas where invasion is advanced, crayfish pose major economic and ecological problems. Crayfish have been widely introduced for aquaculture and can become established in a wide range of habitat conditions. They also may be spread by anglers who use them as bait. Several non-native crayfish are established in the PNW, but the extent of their invasion is not well known. At least two groups are known from scattered sites in the PNW, and both have proven problematic for native species in other parts of the world: Red swamp crayfish (Procambarus clarkii) and several members of the genus Orconectes. Both groups are native to areas of the eastern United States. Both are identified globally as invasives of high concern and appear on the Oregon Department of Fish and Wildlife's "10 Most Unwanted" and the U.S. Forest Service's "Primary Species of Concern" lists for stream systems in the PNW. Despite the presence of introduced crayfish in the PNW and their high potential for negative effects, the scope of their invasion and effects on aquatic systems are not well known. The U.S. Geological Survey (USGS), along with local groups and state agencies, is working to clarify crayfish distribution and to outline which basins may not yet be invaded. Other goals are to improve understanding of habitat associations of invasive crayfish and their potential effects on native crayfish.

  9. Effects of depth and crayfish size on predation risk and foraging profitability of a lotic crayfish

    USGS Publications Warehouse

    Flinders, C.A.; Magoulick, D.D.

    2007-01-01

    We conducted field surveys and experiments to determine whether observed distributions of crayfish among habitats were influenced by differential resource availability, foraging profitability, and predation rates and whether these factors differed with crayfish size and habitat depth. We sampled available food resources (detritus and invertebrates) and shelter as rock substrate in deep (>50 cm) and shallow (<30 cm) habitats. We used an enclosure-exclosure experiment to examine the effects of water depth and crayfish size on crayfish biomass and survival, and to determine whether these factors affected silt accrual, algal abundance (chlorophyll a [chl a]), and detritus and invertebrate biomass (g ash-free dry mass) differently from enclosures without crayfish. We conducted tethering experiments to assess predation on small (13-17 mm carapace length [CL]) and large (23-30 mm CL) Orconectes marchandi and to determine whether predation rates differed with water depth. Invertebrate biomass was significantly greater in shallow water than in deep water, whereas detritus biomass did not differ significantly between depths. Cobble was significantly more abundant in shallow than in deep water. Depth and crayfish size had a significant interactive effect on change in size of enclosed crayfish when CL was used as a measure of size but not when biomass was used as a measure of size. CL of small crayfish increased significantly more in enclosures in shallow than in deep water, but CL of large crayfish changed very little at either depth. Silt, chl a, and detritus biomass were significantly lower on tiles in large- than in small- and no-crayfish enclosures, and invertebrate biomass was significantly lower in large- than in no-crayfish enclosures. Significantly more crayfish were consumed in deep than in shallow water regardless of crayfish size. Our results suggest that predation and resource availability might influence the depth distribution of small and large crayfish. Small

  10. Slow wave sleep in crayfish.

    PubMed

    Ramón, Fidel; Hernández-Falcón, Jesús; Nguyen, Bao; Bullock, Theodore H

    2004-08-10

    Clear evidence of sleep in invertebrates is still meager. Defined as a distinct state of reduced activity, arousability, attention, and initiative, it is well established in mammals, birds, reptiles, and teleosts. It is commonly defined by additional electroencephalographic criteria that are only well established in mammals and to some extent in birds. Sleep states similar to those in mammals, except for electrical criteria, seem to occur in some invertebrates, based on behavior and some physiological observations. Currently the most compelling evidence for sleep in invertebrates (evidence that meets most standard criteria for sleep) has been obtained in the fruit fly Drosophila melanogaster. However, in mammals, sleep is also characterized by a brain state different from that at rest but awake. The electrophysiological slow wave criterion for this state is not seen in Drosophila or in honey bees. Here, we show that, in crayfish, a behavioral state with elevated threshold for vibratory stimulation is accompanied by a distinctive form of slow wave electrical activity of the brain, quite different from that during waking rest. Therefore, crayfish can attain a sleep state comparable to that of mammals. PMID:15286285

  11. [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

  12. Juvenile angiofibroma

    MedlinePlus

    Nasal tumor; Angiofibroma - juvenile; Benign nasal tumor; Juvenile nasal angiofibroma; JNA ... Juvenile angiofibroma is not very common. It is most often found in adolescent boys. The tumor contains ...

  13. Heavy metals in Tuskegee Lake crayfish

    SciTech Connect

    Khan, A.T.

    1995-12-31

    The crayfish, Onconectes virifis, is a bottom dweller and eats insect larvae, worms, crustaceans, small snails, fishes, and dead animal matter. They can be used to monitor the aquatic environment such as lakes, ponds and creeks. To monitor the environmental contamination of heavy metals (Hg, Pb, Cd, Cu, Co, Ni, and Zn) in Tuskegee Lake, Tuskegee, Alabama, adult crayfish were collected and analyzed for these metals. The Pb, Cd, Cu, Ni, and Zn concentrations were 3.91, 0.22, 8.06, 1.11, and 33.37 ppm in muscle and 28.98, 1.15, 9.86, 2.1 8, and 32.62 ppm in exoskeleton of crayfish, respectively. The concentrations of Pb and Cd were significantly higher in exoskeleton than those of muscle. However, the concentrations of Cu, Ni, and Zn did not show any significant difference between the muscle and the exoskeleton of the crayfish. The concentrations of Hg and Co were undetected in both the exoskeleton and muscle of the crayfish.

  14. Control of nuisance populations of crayfish with traps and toxicants

    USGS Publications Warehouse

    Bills, T.D.; Marking, L.L.

    1988-01-01

    Crayfish have long been a nuisance in fish-rearing ponds at fish hatcheries. The rusty crayfish (Orconectes rusticus ) has displaced endemic species and caused serious declines of aquatic plants in some ponds and lakes in the midwestern USA. The authors attempted to evaluate the effect of intensive trapping on a crayfish population and to identify a selective chemical control agent and evaluate its effectiveness under field conditions. A crayfish population in a small pond was suppressed but not eliminated by trapping: adults were effectively harvested but efficiency diminished sharply as the population declined. Of 19 chemicals tested as possible control agents for crayfish, a synthetic pyrethroid (Baythroid) was by far the most toxic; 25 mu g/L produced a complete kill of crayfish in the pond and was also the most selective for crayfish in laboratory tests.

  15. Involvement of the crustacean hyperglycemic hormone (CHH) in the physiological compensation of the freshwater crayfish Cherax quadricarinatus to low temperature and high salinity stress.

    PubMed

    Prymaczok, Natalia C; Pasqualino, Valeria M; Viau, Verónica E; Rodríguez, Enrique M; Medesani, Daniel A

    2016-02-01

    This study was aimed at determining the role of the crustacean hyperglycemic hormone (CHH) in the physiological compensation to both saline and thermal stress, in the freshwater crayfish Cherax quadricarinatus. By determining the expression of the CHH gene in the eyestalk of juvenile crayfish, we found that maximal induction of CHH was induced at high salinity (10 g/L) and low temperature (20 °C). In order to investigate the role of CHH in the physiological compensation to such stressful conditions, recombinant CHH was supplied to stressed animals. CHH-injected crayfish showed increased hemolymphatic levels of glucose, in accordance with a significant utilization of glycogen reserves from the hepatopancreas. Furthermore, CHH administration allowed stressed animals to regulate hemolymphatic sodium and potassium at more constant levels than controls. Taken together, these results suggest a relevant role of CHH in increasing the energy available intended for processes involved in the physiological compensation of C. quadricarinatus to both saline and thermal stress.

  16. Crayfish plague Aphanomyces astaci detected in redclaw crayfish, Cherax quadricarinatus in Taiwan.

    PubMed

    Hsieh, Chia-Yu; Huang, Chen-Wei; Pan, Yi-Cheng

    2016-05-01

    Between December 2013 and January 2014, five outbreaks of an unknown disease with moderate to high cumulative mortality were observed among the freshwater redclaw crayfish (Cherax quadricarinatus) populations at four crayfish farms in Miaoli and Changhua counties (northern Taiwan) and at one crayfish farm in Pingtung County (southern Taiwan). Polymerase chain reaction (PCR) analysis allowed the detection of Aphanomyces astaci DNA in dead crayfish. Histopathological examination revealed an infection of host tissue by fungal hyphae that presented as typical non-septate hyphae within the soft abdominal cuticle from the first to second segment and in the tail fan. In PCR assays completed for the detection of crayfish plague, an expected 568-bp product, specific for the A. astaci ITS gene, was obtained from all sub-adults and adults examined. In a comparison of our strains with the known strains of A. astaci in Europe, nucleotide sequence identities were very similar, with 99.8-100% sequence similarity in that gene region. Positive reactions to in situ hybridization, using a digoxigenin (DIG)-labelled DNA probe, further confirmed A. astaci as the causative agent. This is the first report concerning natural infection of A. astaci in freshwater redclaw crayfish in Asia. PMID:27039156

  17. Distribution and conservation standing of West Virginia crayfishes

    USGS Publications Warehouse

    Loughman, Zachary J.; Welsh, Stuart

    2010-01-01

    The diversity of crayfishes in West Virginia represents a transition between the species-rich southern Appalachian faunas and the depauperate crayfish diversity in the northeastern United States. Currently, 22 described species occur in the state, of which 6 are given S1 status, and 3 are introduced species. One species, Orconectes limosus (Spinycheek Crayfish) is considered extirpated within the past decade. Imperiled species include Cambarus veteranus (Big Sandy Crayfish),Cambarus elkensis (Elk River Crayfish), Cambarus longulus (Atlantic Slope Crayfish), andCambarus nerterius (Greenbrier Cave Crayfish). Three species—O. virilis (Virile Crayfish),Orconectes rusticus (Rusty Crayfish), and Procambarus zonangulus (Southern White River Crawfish)—have introduced populations within the state. Procambarus acutus (White River Crawfish) occurs in bottomland forest along the Ohio River floodplain, and is considered native. Several undescribed taxa have been identified and currently are being described. A statewide survey was initiated in 2007 to document the current distribution and conservation status of crayfishes in West Virginia.

  18. Timing and quantifying Aphanomyces astaci sporulation from the noble crayfish suffering from the crayfish plague.

    PubMed

    Makkonen, J; Strand, D A; Kokko, H; Vrålstad, T; Jussila, J

    2013-03-23

    Aphanomyces astaci sporulation is crucial for the spreading potential of this disease agent. For the first time, we are reporting timing and quantity of A. astaci spores released from noble crayfish (Astacus astacus) suffering from crayfish plague under practical aquatic conditions. We infected nine noble crayfish with A. astaci PsI-genotype and maintained them in individual 8L tanks. Spores (zoospores and cysts) were quantified from water samples (3 × 1 mL) taken every 12h over 10 d using A. astaci specific qPCR. A clear sporulation trend was found, together with a high individual spore estimate variation. The median spore counts from two days before death to 12h post mortem were from ~500 to ~2000 spores L(-1). A significant sporulation increase occurred after 24h post mortem (~12,000 spores L(-1)) and reached a peak after two days (~65,000 spores L(-1)) before declining to or below pre mortem levels from the fourth day. The single most sporulating crayfish released from ~75,000 to ~400,000 spores L(-1) during the mass sporulating period, yielding a maximum estimate of ~3,200,000 spores released from a single crayfish if we assume homogeneous spore distribution. The results confirm a mass A. astaci spore release from moribund and recently dead infected noble crayfish, with a sporulation peak one to three days post mortem. The acute crayfish mortality only three days after zoospore exposure confirm the lethal potential of the PsI-genotype. The powerful sporulation potential observed here may be one of the key virulence factors of this genotype.

  19. Response of crayfish to hyporheic water availability and excess sedimentation

    USGS Publications Warehouse

    Dyer, Joseph J.; Worthington, Thomas A.; Brewer, Shannon K.

    2015-01-01

    Crayfish in many headwater streams regularly cope with seasonal drought. However, it is unclear how landscape changes affect the long-term persistence of crayfish populations. We designed two laboratory experiments to investigate the acute effects of common landscape stressors on crayfish: water withdrawal and sedimentation. The first experiment tested the interaction among water withdrawals (four 24-h water reductions of 0, 15, 30, or 45 cm) and two substrate treatments (pebble and cobble) on the burrowing depth of crayfish. The second experiment evaluated the effects of excess fine sediment (three treatments of 0, 45, and 90% sediment) and substrate type (cobble and pebble) on crayfish burrowing depth. Crayfish were able to burrow deeper into the simulated hyporheic zone in cobble substrate when compared to pebble. Crayfish subjected to greater water withdrawals in the pebble treatment were not able to reach the simulated hyporheic zone. Excess fine sediment reduced the depth that crayfish burrowed, regardless of substrate type. Results from this study suggest excess fine sediment may reduce crayfish persistence, particularly when seeking refuge during prolonged dry conditions.

  20. Nitric oxide synthase in crayfish walking leg ganglia: segmental differences in chemo-tactile centers argue against a generic role in sensory integration.

    PubMed

    Ott, Swidbert R; Aonuma, Hitoshi; Newland, Philip L; Elphick, Maurice R

    2007-03-20

    Nitric oxide (NO) is a diffusible signaling molecule with evolutionarily conserved roles in neural plasticity. Prominent expression of NO synthase (NOS) in the primary olfactory centers of mammals and insects lead to the notion of a special role for NO in olfaction. In insects, however, NOS is also strongly expressed in non-olfactory chemo-tactile centers of the thoracic nerve cord. The functional significance of this apparent association with various sensory centers is unclear, as is the extent to which it occurs in other arthropods. We therefore investigated the expression of NOS in the pereopod ganglia of crayfish (Pacifastacus lenisculus and Procambarus clarkii). Conventional NADPH diaphorase (NADPHd) staining after formaldehyde fixation gave poor anatomic detail, whereas fixation in methanol/formalin (MF-NADPHd) resulted in Golgi-like staining, which was supported by immunohistochemistry using NOS antibodies that recognize a 135-kDa protein in crayfish. MF-NADPHd revealed an exceedingly dense innervation of the chemo-tactile centers. As in insects, this innervation was provided by a system of prominent intersegmental neurons. Superimposed on a putatively conserved architecture, however, were pronounced segmental differences. Strong expression occurred only in the anterior three pereopod ganglia, correlating with the presence of claws on pereopods one to three. These clawed pereopods, in addition to their role in locomotion, are crucially involved in feeding, where they serve both sensory and motor functions. Our findings indicate that strong expression of NOS is not a universal feature of primary sensory centers but instead may subserve a specific requirement for sensory plasticity that arises only in particular behavioral contexts.

  1. Differing virulence of Aphanomyces astaci isolates and elevated resistance of noble crayfish Astacus astacus against crayfish plague.

    PubMed

    Makkonen, J; Jussila, J; Kortet, R; Vainikka, A; Kokko, H

    2012-12-27

    Crayfish plague epidemics (caused by Aphanomyces astaci) have been causing population collapses among native European crayfish stocks since the late 1800s. Recent indirect and direct evidence has shown that its virulence has been variable, with native European crayfish even acting as carriers. We tested the differences in A. astaci virulence under experimental conditions using both PsI- and As-genotypes with 3 Finnish noble crayfish Astacus astacus populations. We infected crayfish with adjusted quantities of A. astaci zoospores and monitored the symptoms and mortality of the crayfish. The PsI-genotype isolate caused rapid and total mortality among the tested populations, while the As-genotype isolates expressed more variable virulence. In some cases, mortality among the As-genotype-infected crayfish did not exceed the mortality level of the control group. All of the tested noble crayfish stocks showed lower mortality towards the As-genotype of A. astaci isolated from the River Kemijoki epidemic. We conclude that there are clear differences in virulence between different A. astaci genotypes and also differences in virulence within As-genotypes. Furthermore, we observed clear signs of increased resistance in different populations of noble crayfish towards some of the tested strains belonging to the As-genotype of A. astaci.

  2. Sex identification in female crayfish is bimodal

    NASA Astrophysics Data System (ADS)

    Aquiloni, Laura; Massolo, Alessandro; Gherardi, Francesca

    2009-01-01

    Sex identification has been studied in several species of crustacean decapods but only seldom was the role of multimodality investigated in a systematic fashion. Here, we analyse the effect of single/combined chemical and visual stimuli on the ability of the crayfish Procambarus clarkii to identify the sex of a conspecific during mating interactions. Our results show that crayfish respond to the offered stimuli depending on their sex. While males rely on olfaction alone for sex identification, females require the combination of olfaction and vision to do so. In the latter, chemical and visual stimuli act as non-redundant signal components that possibly enhance the female ability to discriminate potential mates in the crowded social context experienced during mating period. This is one of the few clear examples in invertebrates of non-redundancy in a bimodal communication system.

  3. Metamodulation of the crayfish escape circuit.

    PubMed

    Edwards, Donald H; Yeh, Shih-Rung; Musolf, Barbara E; Antonsen, Brian L; Krasne, Franklin B

    2002-01-01

    Neuromodulation provides a means of changing the excitability of neurons or the effect of synapses, and so extends the performance range of neural circuits. Metamodulation occurs when the neuromodulatory effect is itself modulated, often in response to a change in the behavioral state of the animal. The well-studied neural circuit that mediates escape in the crayfish is modulated by serotonin, and this modulation is subject to two forms of metamodulation. First, the serotonergic modulation of the Lateral Giant (LG) command neuron for escape depends on the pattern of exposure of the cell to serotonin. High and low concentrations, and rapid and slow exposures each produce opposite modulatory effects on sensory-evoked EPSPs in LG. In addition, brief exposures produce transient modulatory effects, whereas longer exposures produce long-term facilitation. These different patterns of exposure may result from serotonin neurotransmission, paracrine transmission, and hormonal release, all of which occur in the vicinity of LG. The second form of metamodulation enables serotonergic modulation to track slow changes in the social status of the crayfish. Slowly applied serotonin facilitates LG's response in socially isolated crayfish and in new dominant and subordinate animals. Facilitation is retained in the dominant animal during two weeks of continuous pairing of the animals, but facilitation gradually changes to inhibition in the subordinate crayfish. These and related changes in serotonin modulation appear to result from changes in the population of serotonin receptors that mediate the modulatory effects in LG. Whereas the exposure-dependent metamodulation enables rapid changes in serotonergic modulation of LG to occur, the status-dependent metamodulation enables serotonergic modulation of LG to track the slow maturation of social relationships. PMID:12563168

  4. Estimating prey size and number in crayfish-eating snakes, genus Regina

    USGS Publications Warehouse

    Godley, J.S.; McDiarmid, R.W.; Rojas, N.N.

    1984-01-01

    Snakes of the genus Regina feed almost exclusively on crayfish. The paired, symmetrical gastroliths of crayfish are not digested and are detectable from x-rays of the snake. Gastrolith length is directly proportional to carapace length and can be obtained from x-rays. Carapace length can be converted to kcal of ingested energy. Using these relationships and repeated captures of radio-telemetered Regina, estimates of food consumption and energy intake by freeliving snakes are feasible. New information on prey selectivity, feeding behavior, and predator-prey size relations in Regina grahami and R. septemvittata are presented and compared with similar data for other snakes.

  5. Effects of Crayfish on Quality of Fine Particulate Organic Matter

    NASA Astrophysics Data System (ADS)

    Montemarano, J. J.; Kershner, M. W.; Leff, L. G.

    2005-05-01

    The origin and ontogeny of detritus often determines its bioavailability. Crayfish shred and consume detrital organic matter, influencing fine particulate organic matter (FPOM) availability, composition and quality. Given consumption of FPOM by many invertebrates, crayfish can indirectly affect these organisms by altering FPOM bioavailability through organic matter fragmentation, biofilm disturbance, and defecation. These effects may or may not vary among coarse particulate organic matter (CPOM) from different leaf species. To assess crayfish effects on FPOM quality, crayfish were fed stream-conditioned maple or oak leaves in hanging 1-mm mesh-bottom baskets in aquaria. After 12 h, crayfish and remaining leaves were removed. FPOM fragments that fell through the mesh were vacuum filtered and analyzed for percent organic matter, C:N ratio, and bacterial abundance. The same analyses were conducted on crayfish feces collected using finger cots encasing crayfish abdomens. C:N ratios did not differ between feces and maple leaf CPOM, but were lower in FPOM produced through fragmentation and disturbance (P = 0.023). Overall, crayfish alter the ontogeny of detritus, which may, in turn, affect stream FPOM dynamics.

  6. Genotoxicity monitoring of freshwater environments using caged crayfish (Astacus leptodactylus).

    PubMed

    Klobučar, Göran I V; Malev, Olga; Šrut, Maja; Štambuk, Anamaria; Lorenzon, Simonetta; Cvetković, Želimira; Ferrero, Enrico A; Maguire, Ivana

    2012-03-01

    Genotoxicity of freshwater pollution was assessed by measuring DNA damage in haemocytes of caged freshwater crayfish Astacus leptodactylus by the means of Comet assay and micronucleus test, integrated with the measurements of physiological (total protein concentration) and immunological (total haemocyte count) haemolymph parameters as biomarkers of undergone stress. Crayfish were collected at the reference site (River Mrežnica) and exposed in cages for 1 week at three polluted sites along the Sava River (Zagreb, Sisak, Krapje). The long term pollution status of these locations was confirmed by chemical analyses of sediments. Statistically significant increase in DNA damage measured by the Comet assay was observed at all three polluted sites comparing to the crayfish from reference site. In addition, native crayfish from the mildly polluted site (Krapje) cage-exposed on another polluted site (Zagreb) showed lower DNA damage than crayfish from the reference site exposed at the same location indicating adaptation and acclimatisation of crayfish to lower levels of pollution. Micronuclei induction showed similar gradient of DNA damage as Comet assay, but did not reach the statistical significance. Observed increase in total haemocyte count and total protein content in crayfish from polluted environments in the Sava River also confirmed stress caused by exposure to pollution. The results of this study have proved the applicability of caging exposure of freshwater crayfish A. leptodactylus in environmental genotoxicity monitoring using Comet assay and micronucleus test.

  7. Effects of habitat structure and risk of cannibalism on life-history traits of red swamp crayfish (Procambarus clarki)

    NASA Astrophysics Data System (ADS)

    McCabe, D.; Fradette, K. J.; Usowski, A. E.

    2005-05-01

    The effects of habitat structure on predator-prey interactions and intra-guild predation have been well studied in a number of ecological and laboratory systems. How intraspecific interactions among members of cannibalistic species are affected by habitat structure has received less attention. We measured the impacts of habitat structure on interspecific aggression, cannibalism, and life-history traits of Procambarus clarki. Crayfish were randomly assigned to structured or simple habitats. Structured habitats consisted of aquaria with four ceramic fire bricks each with three circular holes for shelter; simple habitats lacked shelters. We hypothesized that habitat structure would lead to decreased injury frequency, increased molting frequency, greater survival, and higher reproductive output in crayfish. Reproductive output did not differ between treatments, but juvenile survival was higher in the structured habitat. Molting was more frequent in the structured habitat. In sharp contrast to predictions, survival was lower in the structured habitat. We concluded the increased mortality in the structured habitat was due to the high degree of exposure to cannibalism and aggression among the crayfish immediately following molting.

  8. Identified proprioceptive afferents and motor rhythm entrainment in the crayfish walking system.

    PubMed

    Elson, R C; Sillar, K T; Bush, B M

    1992-03-01

    1. In crayfish, Pacifastacus leniusculus, remotion of a walking leg stretches the thoraco-coxal (TC) muscle receptor organ (TCMRO), located at the leg's articulation with the thorax. In vitro, alternate stretch and release of the fourth leg's TCMRO entrained the centrally generated rhythmic motor output to that leg, with the remotor phase of the rhythm entraining to TCMRO stretch, the promoter phase to release. This coordination of motor bursts to afferent input corresponds to that of active, rhythmic movements in vivo. 2. Entrainment was rapid in onset (stable coordination resulting within the first or second stimulus cycle) and was relatively phase-constant (whatever the stimulus frequency, during 1:1 entrainment, remotor bursts began near the onset of stretch and promotor bursts began near the onset of release). Outside the range of 1:1 entrainment, 2:1, 1:2, and 1:3 coordination ratios (rhythm:stimulus) were encountered. Resetting by phasic stimulation of the TCMRO was complete and probabilistic: effective stimuli triggered rapid transitions between the two burst phases. 3. The TCMRO is innervated by two afferents, the nonspiking S and T fibers, which generate graded depolarizing receptor potentials in response to stretch. During proprioceptive entrainment, the more phasic T fiber depolarized and hyperpolarized more rapidly or in advance of the more tonic S fiber. These receptor potentials were modified differently in the two afferents by interaction with central synaptic inputs that were phase-locked to the entrained motor rhythm. 4. Injecting slow sinusoidal current into either afferent alone could entrain motor rhythms: promoter phase bursts were entrained to depolarization of the S fiber or hyperpolarization of the T fiber, whereas the converse response was obtained for remotor phase bursts. 5. During proprioceptive entrainment, tonic hyperpolarization of the S fiber weakened entrained promotor bursts and allowed remotor burst durations to increase

  9. A synthetic phylogeny of freshwater crayfish: insights for conservation.

    PubMed

    Owen, Christopher L; Bracken-Grissom, Heather; Stern, David; Crandall, Keith A

    2015-02-19

    Phylogenetic systematics is heading for a renaissance where we shift from considering our phylogenetic estimates as a static image in a published paper and taxonomies as a hardcopy checklist to treating both the phylogenetic estimate and dynamic taxonomies as metadata for further analyses. The Open Tree of Life project (opentreeoflife.org) is developing synthesis tools for harnessing the power of phylogenetic inference and robust taxonomy to develop a synthetic tree of life. We capitalize on this approach to estimate a synthesis tree for the freshwater crayfish. The crayfish make an exceptional group to demonstrate the utility of the synthesis approach, as there recently have been a number of phylogenetic studies on the crayfishes along with a robust underlying taxonomic framework. Importantly, the crayfish have also been extensively assessed by an IUCN Red List team and therefore have accurate and up-to-date area and conservation status data available for analysis within a phylogenetic context. Here, we develop a synthesis phylogeny for the world's freshwater crayfish and examine the phylogenetic distribution of threat. We also estimate a molecular phylogeny based on all available GenBank crayfish sequences and use this tree to estimate divergence times and test for divergence rate variation. Finally, we conduct EDGE and HEDGE analyses and identify a number of species of freshwater crayfish of highest priority in conservation efforts.

  10. A synthetic phylogeny of freshwater crayfish: insights for conservation.

    PubMed

    Owen, Christopher L; Bracken-Grissom, Heather; Stern, David; Crandall, Keith A

    2015-02-19

    Phylogenetic systematics is heading for a renaissance where we shift from considering our phylogenetic estimates as a static image in a published paper and taxonomies as a hardcopy checklist to treating both the phylogenetic estimate and dynamic taxonomies as metadata for further analyses. The Open Tree of Life project (opentreeoflife.org) is developing synthesis tools for harnessing the power of phylogenetic inference and robust taxonomy to develop a synthetic tree of life. We capitalize on this approach to estimate a synthesis tree for the freshwater crayfish. The crayfish make an exceptional group to demonstrate the utility of the synthesis approach, as there recently have been a number of phylogenetic studies on the crayfishes along with a robust underlying taxonomic framework. Importantly, the crayfish have also been extensively assessed by an IUCN Red List team and therefore have accurate and up-to-date area and conservation status data available for analysis within a phylogenetic context. Here, we develop a synthesis phylogeny for the world's freshwater crayfish and examine the phylogenetic distribution of threat. We also estimate a molecular phylogeny based on all available GenBank crayfish sequences and use this tree to estimate divergence times and test for divergence rate variation. Finally, we conduct EDGE and HEDGE analyses and identify a number of species of freshwater crayfish of highest priority in conservation efforts. PMID:25561670

  11. A synthetic phylogeny of freshwater crayfish: insights for conservation

    PubMed Central

    Owen, Christopher L.; Bracken-Grissom, Heather; Stern, David; Crandall, Keith A.

    2015-01-01

    Phylogenetic systematics is heading for a renaissance where we shift from considering our phylogenetic estimates as a static image in a published paper and taxonomies as a hardcopy checklist to treating both the phylogenetic estimate and dynamic taxonomies as metadata for further analyses. The Open Tree of Life project (opentreeoflife.org) is developing synthesis tools for harnessing the power of phylogenetic inference and robust taxonomy to develop a synthetic tree of life. We capitalize on this approach to estimate a synthesis tree for the freshwater crayfish. The crayfish make an exceptional group to demonstrate the utility of the synthesis approach, as there recently have been a number of phylogenetic studies on the crayfishes along with a robust underlying taxonomic framework. Importantly, the crayfish have also been extensively assessed by an IUCN Red List team and therefore have accurate and up-to-date area and conservation status data available for analysis within a phylogenetic context. Here, we develop a synthesis phylogeny for the world's freshwater crayfish and examine the phylogenetic distribution of threat. We also estimate a molecular phylogeny based on all available GenBank crayfish sequences and use this tree to estimate divergence times and test for divergence rate variation. Finally, we conduct EDGE and HEDGE analyses and identify a number of species of freshwater crayfish of highest priority in conservation efforts. PMID:25561670

  12. Crayfish (Orconectes virilis) predation on zebra mussels (Dreissena polymorpha)

    USGS Publications Warehouse

    Love, Joy; Savino, Jacqueline F.

    1993-01-01

    In laboratory studies, we quantified predation rates and handling time of crayfish (Orconectes virilis) on zebra mussels (Dreissena polymorpha) and rainbow trout (Oncorhhynchus mykiss) eggs. In single prey species tests, crayfish ate zebra mussels at similar rates as they ate rainbow trout eggs. When both prey were present, crayfish preferred rainbow trout eggs. Handling time of mussels was about twice that of rainbow trout eggs, and energetic content of mussels was lower. Therefore, net benefit for foraging on rainbow trout eggs was about three times that of foraging on zebra mussels.

  13. Juvenile Arthritis

    MedlinePlus

    Juvenile arthritis (JA) is arthritis that happens in children. It causes joint swelling, pain, stiffness, and loss ... common type of JA that children get is juvenile idiopathic arthritis. There are several other forms of ...

  14. Impacts of drought and crayfish invasion on stream ecosystem structure and function

    USGS Publications Warehouse

    Magoulick, Daniel D.

    2014-01-01

    Drought and seasonal drying can be important disturbance events in many small streams, leading to intermittent or isolated habitats. Many small streams contain crayfish populations that are often keystone or dominant species in these systems. I conducted an experiment in stream mesocosms to examine the effects of drought and potential ecological redundancy of a native and invasive crayfish species. I examined the effects of drought (drought or control) and crayfish presence (none, native crayfish Orconectes eupunctus or invasive crayfish Orconectes neglectus) on stream mesocosm structure and function (leaf breakdown, community metabolism, periphyton, sediment and chironomid densities) in a fully factorial design. Each mesocosm contained a deep and shallow section, and drought treatments had surface water present (5-cm depth) in deep sections where tiles and leaf packs were placed. Drought and crayfish presence did not interact for any response variable. Drought significantly reduced leaf breakdown, and crayfish presence significantly increased leaf breakdown. However, the native and invasive crayfish species did not differ significantly in their effects on leaf breakdown. Drought significantly reduced primary production and community respiration overall, whereas crayfish presence did not significantly affect primary production and community respiration. Neither drought nor crayfish presence significantly affected periphyton overall. However, drought significantly reduced autotrophic index (AI), and crayfish presence increased AI. Inorganic sediment and chironomid density were not affected by drought, but both were significantly reduced by crayfish presence. O. eupunctus reduced AI and sediment more than O. neglectus did. Neither drought nor crayfish species significantly affected crayfish growth or survival. Drought can have strong effects on ecosystem function, but weaker effects on benthic structure. Crayfish can have strong effects on ecosystem

  15. Human exposure to methylmercury from crayfish (Procambarus clarkii) in China.

    PubMed

    Peng, Qian; Greenfield, Ben K; Dang, Fei; Zhong, Huan

    2016-02-01

    Methylmercury (MeHg) accumulation in aquatic food raises global concerns about human exposure to MeHg. Crayfish is the world's third largest farmed crustacean species and a favorite aquatic food in many countries. However, human health hazard due to MeHg exposure via crayfish consumption is unclear, partly because appropriate survey data are lacking. We report on mercury concentrations and speciation in edible tail muscle of crayfish collected from restaurants in 23 Chinese cities. On average, MeHg constituted 99.1 % of mercury in tail muscle, and MeHg concentrations were comparable with those reported for fish in China. Variation in MeHg concentrations was not attributable to broad geographic region (i.e., provinces) or tail length. For different populations, potential health risk (characterized by hazard quotient or HQ) of MeHg exposure through crayfish consumption depended largely on crayfish consumption rates. In particular, a health hazard (HQ > 1) was found for high-rate consumers (i.e., 95 %ile or higher) in some cities in the middle and lower reaches of the Yangtze River (MLYR), during the peak consumption season. Our results suggest that more attention should be paid to dietary MeHg intake via crayfish consumption in China, particularly for communities with high consumption in MLYR.

  16. Conservation and management of crayfishes: Lessons from Pennsylvania

    USGS Publications Warehouse

    Lieb, D.A.; Bouchard, R.W.; Carline, R.F.; Nuttall, T.R.; Wallace, J.R.; Burkholder, C.L.

    2011-01-01

    North America's crayfish fauna is diverse, ecologically important, and highly threatened. Unfortunately, up-to-date information is scarce, hindering conservation and management efforts. In Pennsylvania and nearby states, recent efforts allowed us to determine the conservation status of several native crayfishes and develop management strategies for those species. Due to rarity and proximity to urban centers and introduced (exotic) crayfishes, Cambarus (Puncticambarus) sp., an undescribed member of the Cambarus acuminatus complex, is critically imperiled in Pennsylvania and possibly range-wide. Orconectes limosus is more widespread; however, recent population losses have been substantial, especially in Pennsylvania and northern Maryland, where its range has declined (retreated eastward) by greater than 200 km. Introduced congeners likely played a major role in those losses. Although extirpated from some areas, Cambarus bartonii bartonii remains widespread and is not an immediate conservation concern. In light of these findings, the role of barriers (e.g., dams), environmental protection, educational programs, and regulations in preventing crayfish invasions and conserving native crayfishes is discussed, and management initiatives centered on those factors are presented. The need for methods to eliminate exotics and monitor natives is highlighted. Although tailored to a specific regional fauna, these ideas have broad applicability and would benefit many North American crayfishes. ?? copyright 2011. Periodicals postage paid at Bethesda.

  17. Habituation of LG-mediated tailflip in the crayfish.

    PubMed

    Nagayama, Toshiki; Araki, Makoto

    2015-06-01

    Crayfish escape from threatening stimuli by tailflipping. If a stimulus is applied to the rear, crayfish escape up and forwards in a summersault maneuver that is mediated by the activation of lateral giant (LG) interneurons. The occurrence probability of LG-mediated tailflip, however, diminishes and habituates if a stimulus is repeatedly applied. Since crayfish have a relatively simple CNS with many identifiable neurons, crayfish represent a good animal to analyze the cellular basis of habituation. A reduction in the amplitude of the EPSP in the LGs, caused by direct chemical synaptic connection from sensory afferents by repetitive stimulations, is essential to bring about an inactivation of the LGs. The spike response of the LGs recovers within several minutes of habituation, but the LGs subsequently fail to spike when an additional stimulus is applied after specific periods following habituation. These results indicate that a decline in synaptic efficacy from the mechanosensory afferents recovers readily after a short delay, but then the excitability of the LGs themselves decreases. Furthermore, the processes underlying habituation are modulated depending on a social status. When two crayfish encounter each other, a winner-loser relationship is established. With a short interstimulus interval of 5 s, the rate of habituation of the LG in both socially dominant and subordinate crayfish becomes lower than in socially isolated animals. Serotonin and octopamine affect this social status-dependent modulation of habituation by means of activation of downstream second messenger system of cAMP and IP3 cascades, respectively.

  18. Molecular detection and genotyping of Aphanomyces astaci directly from preserved crayfish samples uncovers the Norwegian crayfish plague disease history.

    PubMed

    Vrålstad, Trude; Strand, David A; Grandjean, Frédéric; Kvellestad, Agnar; Håstein, Tore; Knutsen, Ann Kristin; Taugbøl, Trond; Skaar, Ida

    2014-09-17

    Aphanomyces astaci causes crayfish plague in European freshwater crayfish, but most historical epizootics lack agent isolation and identification. Although declared as crayfish plague outbreaks by the Norwegian Competent Authorities, only presumptive diagnoses without agent isolation exist from Norwegian epizootics until 2005. Molecular methods now allow both A. astaci detection and genotype determination from preserved samples. We therefore aimed to (1) investigate molecularly if A. astaci was involved in a selection of mass-mortality events in Norwegian noble crayfish populations from 1971 to 2004, and (2) determine the eventually involved A. astaci genotype groups both from these historical and also more recent mass-mortality events. DNA was extracted directly from presumptively infected crayfish tissues, and screened by A. astaci specific qPCR. A representative selection of positive samples was confirmed by ITS-sequencing. Finally, genotype determination was performed with microsatellite markers that distinguish all known A. astaci genotype groups. The molecular examination detected A. astaci in crayfish materials from all examined mass-mortality events. The first event in 1971-1974 was caused by the A. astaci genotype group A, presumably the first genotype group that entered Europe more than 150 years ago. All later outbreaks were caused by the A. astaci genotype group B which was introduced to Europe by importation of signal crayfish in the 1960s. The results suggest that molecular methods can verify the involvement of A. astaci in the vast majority of observed crayfish mass mortalities in Europe whenever preserved materials exist. Moreover, microsatellite genotyping can reveal at least parts of the underlying epidemiology.

  19. Dose-dependent mortality of the noble crayfish (Astacus astacus) to different strains of the crayfish plague (Aphanomyces astaci).

    PubMed

    Makkonen, Jenny; Kokko, Harri; Vainikka, Anssi; Kortet, Raine; Jussila, Japo

    2014-01-01

    Several reports of the European crayfish species carrying a latent infection of the crayfish plague (Aphanomyces astaci) have emerged and the discussion has focused especially on the lowered virulence of As-genotypes behind decreased mortality. The aim of this study was to compare the killing rate of different A. astaci strains in controlled infection experiments. Two separate infection experiments with three A. astaci strains (UEFT2B (As), Evira6462/06 (As) and UEF8866-2 (PsI)) were made to compare the noble crayfish populations from the Lake Viitajärvi, Tervo, (Expt I) and the Lake Mikitänjärvi, Hyrynsalmi (Expt II). In the Expt III, the Lake Koivujärvi population noble crayfish were infected with A. astaci strains UEF8866-2 (PsI) and Evira6462/06 (As) using different dosages (1, 10, 100 and 1000sporesml(-1)) of A. astaci zoospores. The results confirmed that PsI-genotype strain is highly virulent and kills all the crayfish within a few days. The tested two As-genotype strains caused the mortalities more slowly, and part of the challenged crayfish survived until the end of the follow-up period. Our results also confirmed the variance of virulence among A. astaci strains within the As-genotype and demonstrated that the mortality is dependent on the number of zoospores used in the infections. It also appeared, that some noble crayfish populations show increased resistance towards the crayfish plague, especially against the As-genotype of A. astaci.

  20. Ontogenetic variation in food consumption of rusty crayfish (Orconectes rusticus) in a central New York stream

    USGS Publications Warehouse

    Johnson, J.H.; Nack, C.C.

    2010-01-01

    We examined feeding periodicity of three size groups of the rusty crayfish (Orconectes rusticus) at four-hour intervals over a 28-hour period during July in a headwater stream of the Susquehanna River drainage in central New York. Feeding activity was expressed as the ratio of stomach weight divided by the crayfish wet weight. The diel food consumption patterns of all three size groups of rusty crayfish (i.e., ??? 10 mm, 11-20 mm, and > 20 mm carapace length) were significantly different. Peak feeding of the smallest crayfish occurred during crepuscular periods. Food consumption of the intermediate size crayfish was highest at 2000 h, and feeding of large crayfish was consistently high from 1200 h to 0400 h. Feeding intensity of both small and intermediate size crayfish was highest when feeding intensity of large crayfsh was lowest. Ontogenetic differences in feeding periodicity may be associated with predation pressure from large rusty crayfish on smaller individuals.

  1. Ontogenetic Variation in Food Consumption of Rusty Crayfish (Orconectes rusticus) in a Central New York Stream

    USGS Publications Warehouse

    Johnson, James H.; Nack, Christopher C.

    2010-01-01

    We examined feeding periodicity of three size groups of the rusty crayfish (Orconectes rusticus) at four-hour intervals over a 28-hour period during July in a headwater stream of the Susquehanna River drainage in central New York. Feeding activity was expressed as the ratio of stomach weight divided by the crayfish wet weight. The diel food consumption patterns of all three size groups of rusty crayfish (i.e., ≤ 10 mm, 11–20 mm, and > 20 mm carapace length) were significantly different. Peak feeding of the smallest crayfish occurred during crepuscular periods. Food consumption of the intermediate size crayfish was highest at 2000 h, and feeding of large crayfish was consistently high from 1200 h to 0400 h. Feeding intensity of both small and intermediate size crayfish was highest when feeding intensity of large crayfsh was lowest. Ontogenetic differences in feeding periodicity may be associated with predation pressure from large rusty crayfish on smaller individuals.

  2. Gating current "fractionation" in crayfish giant axons.

    PubMed Central

    Starkus, J G; Rayner, M D

    1991-01-01

    Effects of changes in initial conditions on the magnitude and kinetics of gating current and sodium current were studied in voltage-clamped, internally-perfused, crayfish giant axons. We examined the effects of changes in holding potential, inactivating prepulses, and recovery from inactivation in axons with intact fast inactivation. We also studied the effects of brief interpulse intervals in axons pretreated with chloramine-T for removal of fast inactivation. We find marked effects of gating current kinetics induced by both prepulse inactivation and brief interpulse intervals. The apparent changes in gating current relaxation rates cannot be explained simply by changes in gating charge magnitude (charge immobilization) combined with "Cole-Moore-type" time shifts. Rather they appear to indicate selective suppression of kinetically-identifiable components within the control gating currents. Our results provide additional support for a model involving parallel, nonidentical, gating particles. PMID:1760505

  3. A Crayfish Insulin-like-binding Protein

    PubMed Central

    Rosen, Ohad; Weil, Simy; Manor, Rivka; Roth, Ziv; Khalaila, Isam; Sagi, Amir

    2013-01-01

    Across the animal kingdom, the involvement of insulin-like peptide (ILP) signaling in sex-related differentiation processes is attracting increasing attention. Recently, a gender-specific ILP was identified as the androgenic sex hormone in Crustacea. However, moieties modulating the actions of this androgenic insulin-like growth factor were yet to be revealed. Through molecular screening of an androgenic gland (AG) cDNA library prepared from the crayfish Cherax quadricarinatus, we have identified a novel insulin-like growth factor-binding protein (IGFBP) termed Cq-IGFBP. Based on bioinformatics analyses, the deduced Cq-IGFBP was shown to share high sequence homology with IGFBP family members from both invertebrates and vertebrates. The protein also includes a sequence determinant proven crucial for ligand binding, which according to three-dimensional modeling is assigned to the exposed outer surface of the protein. Recombinant Cq-IGFBP (rCq-IGFBP) protein was produced and, using a “pulldown” methodology, was shown to specifically interact with the insulin-like AG hormone of the crayfish (Cq-IAG). Particularly, using both mass spectral analysis and an immunological tool, rCq-IGFBP was shown to bind the Cq-IAG prohormone. Furthermore, a peptide corresponding to residues 23–38 of the Cq-IAG A-chain was found sufficient for in vitro recognition by rCq-IGFBP. Cq-IGFBP is the first IGFBP family member shown to specifically interact with a gender-specific ILP. Unlike their ILP ligands, IGFBPs are highly conserved across evolution, from ancient arthropods, like crustaceans, to humans. Such conservation places ILP signaling at the center of sex-related phenomena in early animal development. PMID:23775079

  4. Baited lines: An active nondestructive collection method for burrowing crayfish

    USGS Publications Warehouse

    Loughman, Zachary J.; Foltz, David A.; Welsh, Stuart

    2013-01-01

    A new method (baited lines) is described for the collection of burrowing crayfishes, where fishing hooks baited with earthworms and tied to monofilament leaders are used to lure crayfishes from their burrow entrances. We estimated capture rates using baited lines at four locations across West Virginia for a total of four crayfish taxa; the taxa studied were orange, blue, and blue/orange morphs of Cambarus dubius (Upland Burrowing Catfish), and C. thomai (Little Brown Mudbug). Baited-line capture rates were lowest for C. thomai (81%; n = 21 attempts) and highest for the orange morph ofC. dubius (99%; n = 13 attempts). The pooled capture rate across all taxa was 91.5% (n = 50 attempts). Baited lines represent an environmentally nondestructive method to capture burrowing crayfishes without harm to individuals, and without disturbing burrows or the surrounding area. This novel method allows for repeat captures and long-term studies, providing a useful sampling method for ecological studies of burrowing crayfishes.

  5. Aminergic control of social status in crayfish agonistic encounters.

    PubMed

    Momohara, Yuto; Kanai, Akihiro; Nagayama, Toshiki

    2013-01-01

    Using pairings of male crayfish Procambarus clarkii with a 3-7% difference in size, we confirmed that physically larger crayfish were more likely to win encounters (winning probability of over 80%). Despite a physical disadvantage, small winners of the first pairings were more likely to win their subsequent conflicts with larger naive animals (winning probability was about 70%). By contrast, the losers of the first pairings rarely won their subsequent conflicts with smaller naive animals (winning probability of 6%). These winner and loser effects were mimicked by injection of serotonin and octopamine. Serotonin-injected naive small crayfish were more likely to win in pairings with untreated larger naive crayfish (winning probability of over 60%), while octopamine-injected naive large animals were beaten by untreated smaller naive animals (winning probability of 20%). Furthermore, the winner effects of dominant crayfish were cancelled by the injection of mianserin, an antagonist of serotonin receptors and were reinforced by the injection of fluoxetin, serotonin reuptake inhibitor, just after the establishment of social order of the first pairings. Injection of octopamine channel blockers, phentolamine and epinastine, by contrast, cancelled the loser effects. These results strongly suggested that serotonin and octopamine were responsible for winner and loser effects, respectively.

  6. Aminergic Control of Social Status in Crayfish Agonistic Encounters

    PubMed Central

    Momohara, Yuto; Kanai, Akihiro; Nagayama, Toshiki

    2013-01-01

    Using pairings of male crayfish Procambarus clarkii with a 3–7% difference in size, we confirmed that physically larger crayfish were more likely to win encounters (winning probability of over 80%). Despite a physical disadvantage, small winners of the first pairings were more likely to win their subsequent conflicts with larger naive animals (winning probability was about 70%). By contrast, the losers of the first pairings rarely won their subsequent conflicts with smaller naive animals (winning probability of 6%). These winner and loser effects were mimicked by injection of serotonin and octopamine. Serotonin-injected naive small crayfish were more likely to win in pairings with untreated larger naive crayfish (winning probability of over 60%), while octopamine-injected naive large animals were beaten by untreated smaller naive animals (winning probability of 20%). Furthermore, the winner effects of dominant crayfish were cancelled by the injection of mianserin, an antagonist of serotonin receptors and were reinforced by the injection of fluoxetin, serotonin reuptake inhibitor, just after the establishment of social order of the first pairings. Injection of octopamine channel blockers, phentolamine and epinastine, by contrast, cancelled the loser effects. These results strongly suggested that serotonin and octopamine were responsible for winner and loser effects, respectively. PMID:24058575

  7. The diversity of oomycetes on crayfish: morphological vs. molecular identification of cultures obtained while isolating the crayfish plague pathogen.

    PubMed

    Kozubíková-Balcarová, Eva; Koukol, Ondřej; Martín, María P; Svoboda, Jiří; Petrusek, Adam; Diéguez-Uribeondo, Javier

    2013-10-01

    Numerous oomycetes colonise the crayfish cuticle, the best known being the crayfish plague pathogen Aphanomyces astaci. Although other oomycetes associated with crayfish complicate the isolation and molecular detection of A. astaci, their diversity is little known. To improve this knowledge, we analysed 95 oomycete isolates obtained during attempts to isolate A. astaci from crayfish presumably infected by this pathogen. We characterized the isolates morphologically and by sequencing of the nuclear internal transcribed spacer (ITS) region. We identified 13 taxa by molecular analysis. Ten of them were assigned to five genera; the remaining three were affiliated with the order Saprolegniales but could not be reliably assigned to any genus. Morphological identification to species level was only possible for 15 % of isolates; all corresponded to Saprolegnia ferax, which was confirmed by ITS sequencing. The most frequently isolated species were S. ferax and Saprolegnia australis. Only seven isolates of A. astaci were obtained, all from one disease outbreak. We show that oomycete cultures obtained as by-products of parasite isolation are valuable for oomycete diversity studies, but morphological identification may uncover only a fraction of their diversity. Further, we show that crayfish may be frequently associated with potentially serious parasites of other organisms.

  8. The marbled crayfish as a paradigm for saltational speciation by autopolyploidy and parthenogenesis in animals

    PubMed Central

    Vogt, Günter; Falckenhayn, Cassandra; Schrimpf, Anne; Schmid, Katharina; Hanna, Katharina; Panteleit, Jörn; Helm, Mark; Schulz, Ralf; Lyko, Frank

    2015-01-01

    ABSTRACT The parthenogenetic all-female marbled crayfish is a novel research model and potent invader of freshwater ecosystems. It is a triploid descendant of the sexually reproducing slough crayfish, Procambarus fallax, but its taxonomic status has remained unsettled. By cross-breeding experiments and parentage analysis we show here that marbled crayfish and P. fallax are reproductively separated. Both crayfish copulate readily, suggesting that the reproductive barrier is set at the cytogenetic rather than the behavioural level. Analysis of complete mitochondrial genomes of marbled crayfish from laboratory lineages and wild populations demonstrates genetic identity and indicates a single origin. Flow cytometric comparison of DNA contents of haemocytes and analysis of nuclear microsatellite loci confirm triploidy and suggest autopolyploidisation as its cause. Global DNA methylation is significantly reduced in marbled crayfish implying the involvement of molecular epigenetic mechanisms in its origination. Morphologically, both crayfish are very similar but growth and fecundity are considerably larger in marbled crayfish, making it a different animal with superior fitness. These data and the high probability of a divergent future evolution of the marbled crayfish and P. fallax clusters suggest that marbled crayfish should be considered as an independent asexual species. Our findings also establish the P. fallax–marbled crayfish pair as a novel paradigm for rare chromosomal speciation by autopolyploidy and parthenogenesis in animals and for saltational evolution in general. PMID:26519519

  9. The marbled crayfish as a paradigm for saltational speciation by autopolyploidy and parthenogenesis in animals.

    PubMed

    Vogt, Günter; Falckenhayn, Cassandra; Schrimpf, Anne; Schmid, Katharina; Hanna, Katharina; Panteleit, Jörn; Helm, Mark; Schulz, Ralf; Lyko, Frank

    2015-01-01

    The parthenogenetic all-female marbled crayfish is a novel research model and potent invader of freshwater ecosystems. It is a triploid descendant of the sexually reproducing slough crayfish, Procambarus fallax, but its taxonomic status has remained unsettled. By cross-breeding experiments and parentage analysis we show here that marbled crayfish and P. fallax are reproductively separated. Both crayfish copulate readily, suggesting that the reproductive barrier is set at the cytogenetic rather than the behavioural level. Analysis of complete mitochondrial genomes of marbled crayfish from laboratory lineages and wild populations demonstrates genetic identity and indicates a single origin. Flow cytometric comparison of DNA contents of haemocytes and analysis of nuclear microsatellite loci confirm triploidy and suggest autopolyploidisation as its cause. Global DNA methylation is significantly reduced in marbled crayfish implying the involvement of molecular epigenetic mechanisms in its origination. Morphologically, both crayfish are very similar but growth and fecundity are considerably larger in marbled crayfish, making it a different animal with superior fitness. These data and the high probability of a divergent future evolution of the marbled crayfish and P. fallax clusters suggest that marbled crayfish should be considered as an independent asexual species. Our findings also establish the P. fallax-marbled crayfish pair as a novel paradigm for rare chromosomal speciation by autopolyploidy and parthenogenesis in animals and for saltational evolution in general.

  10. Involvement of the crustacean hyperglycemic hormone (CHH) in the physiological compensation of the freshwater crayfish Cherax quadricarinatus to low temperature and high salinity stress.

    PubMed

    Prymaczok, Natalia C; Pasqualino, Valeria M; Viau, Verónica E; Rodríguez, Enrique M; Medesani, Daniel A

    2016-02-01

    This study was aimed at determining the role of the crustacean hyperglycemic hormone (CHH) in the physiological compensation to both saline and thermal stress, in the freshwater crayfish Cherax quadricarinatus. By determining the expression of the CHH gene in the eyestalk of juvenile crayfish, we found that maximal induction of CHH was induced at high salinity (10 g/L) and low temperature (20 °C). In order to investigate the role of CHH in the physiological compensation to such stressful conditions, recombinant CHH was supplied to stressed animals. CHH-injected crayfish showed increased hemolymphatic levels of glucose, in accordance with a significant utilization of glycogen reserves from the hepatopancreas. Furthermore, CHH administration allowed stressed animals to regulate hemolymphatic sodium and potassium at more constant levels than controls. Taken together, these results suggest a relevant role of CHH in increasing the energy available intended for processes involved in the physiological compensation of C. quadricarinatus to both saline and thermal stress. PMID:26660884

  11. Effects of Caffeine on Crayfish Muscle Fibers

    PubMed Central

    Chiarandini, Dante J.; Reuben, John P.; Brandt, Philip W.; Grundfest, Harry

    1970-01-01

    Contractions are evoked in single muscle fibers of crayfish by intracellular as well as extracellular applications of caffeine. Responses to external applications in concentrations above 2 mM could be induced indefinitely. With concentrations above 5 mM the caffeine-induced responses were highly repeatable. Tensions were transient even when the caffeine remained in the bath. There was no change in resting potential, but during the contraction the effective resistance decreased about 10%. A number of factors (change in pH, Ca, K, and Cl) modified the responses. The time course of the tension was greatly prolonged when the transverse tubular system (TTS) was s swollen and was again shortened when the TTS was caused to shrink. An increased permeability to Ca induced by caffeine was evidenced by the transformation of the normally graded electrical responses to Ca spikes, which are insensitive to tetrodotoxin. The overshoot is a function of both external Ca and caffeine. A 10-fold change in Ca changed the overshoot by 19 mv in the presence of 10 mM caffeine and by 29 mv in 80 mM caffeine. The role of the increased permeability to Ca for caffeine-induced contractions will be analyzed in the accompanying paper. PMID:5443468

  12. Effects of Caffeine on Crayfish Muscle Fibers

    PubMed Central

    Chiarandini, Dante J.; Reuben, John P.; Girardier, Lucien; Katz, George M.; Grundfest, Harry

    1970-01-01

    When caffeine evokes a contraction, and only then, crayfish muscle fibers become refractory to a second challenge with caffeine for up to 20 min in the standard saline (5 mM Ko). However, the fibers still respond with contraction to an increase in Ko, though with diminished tension. Addition of Mn slows recovery, but the latter is greatly accelerated during exposure of the fiber to high Ko, or after a brief challenge with high Ko. Neither the depolarization induced by the K, nor the repolarization after its removal accounts for the acceleration, which occurs only if the challenge with K had itself activated the contractile system; acceleration is blocked when contractile responses to K are blocked by reducing the Ca in the bath or by adding Mn. Recovery is accelerated by redistribution of intracellular Cl and by trains of intracellularly applied depolarizing pulses, but not by hyperpolarization. The findings indicate that two sources of Ca can be mobilized to activate the contractile system. Caffeine mobilizes principally the Ca store of the SR. Depolarizations that are induced by high Ko, by transient efflux of Cl, or by intracellularly applied currents mobilize another source of Ca which is strongly dependent upon the entry of Ca from the bathing medium. The sequestering mechanism of the SR apparently can utilize this second source of Ca to replenish its own store so as to accelerate recovery of responsiveness to a new challenge with caffeine. PMID:5443469

  13. Temporal dynamics of spore release of the crayfish plague pathogen from its natural host, American spiny-cheek crayfish (Orconectes limosus), evaluated by transmission experiments.

    PubMed

    Svoboda, J; Kozubíková-Balcarová, E; Kouba, A; Buřič, M; Kozák, P; Diéguez-Uribeondo, J; Petrusek, A

    2013-05-01

    The crayfish plague pathogen, Aphanomyces astaci, is one of the most serious threats to indigenous European crayfish species. The North American invasive spiny-cheek crayfish, Orconectes limosus, is an important source of this pathogen in central and western Europe. We evaluated potential changes in A. astaci spore release rate from infected individuals of this species by experiments investigating the pathogen transmission to susceptible noble crayfish, Astacus astacus. We filtered defined volumes of water regularly to quantify spore concentration, and sampled crayfish tissues at the end of the experiment. The filters and tissues were then tested for the presence of A. astaci DNA by species-specific quantitative PCR. Additionally, we tested the efficiency of horizontal transmission to apparently uninfected O. limosus. The experiments confirmed that A. astaci can be transmitted to susceptible crayfish during intermoult periods, and that the pathogen was more frequently detected in noble crayfish recipients than in American ones. The pathogen spore concentrations substantially varied in time, and significantly increased during moulting of infected hosts. Our study strengthens the evidence that although the likelihood of crayfish plague transmission by water transfer from localities with infected American crayfish might increase when these are moulting or dying, no time-periods can be proclaimed safe.

  14. Parasites alter freshwater communities in mesocosms by modifying invasive crayfish behavior.

    PubMed

    Reisinger, Lindsey S; Lodge, David M

    2016-06-01

    Parasites can alter communities by reducing densities of keystone hosts, but few studies have examined how trait-mediated indirect effects of parasites can alter ecological communities. We test how trematode parasites (Microphallus spp.) that affect invasive crayfish (Orconectes rusticus) behavior alter how crayfish impact lake littoral communities. O. rusticus drive community composition in north temperate lakes, and predatory fish can reduce crayfish activity and feeding. In laboratory studies, Microphallus parasites also alter O. rusticus behavior: infected O. rusticus eat fewer macroinvertebrates and are bolder near predatory fish than uninfected individuals. We used a 2 x 2 factorial experiment to test how predatory fish and parasites affect O. rusticus impacts in large mesocosms over 4 weeks. We predicted (1) that when predators were absent, infected crayfish would have lower impacts than uninfected crayfish on macrophytes and macroinvertebrates (as well as reduced growth and higher mortality). However, (2) when predators were present but unable to consume crayfish, infected crayfish would have greater impacts (as well as greater growth and lower mortality) than uninfected crayfish because of increased boldness. Because of its effect on crayfish feeding behavior, we also predicted (3) that infection would alter macrophyte and macroinvertebrate community composition. In contrast to our first hypothesis, we found that infected and uninfected crayfish had similar impacts on lower trophic levels when predators were absent. Across all treatments, infected crayfish were more likely to be outside shelters and had greater growth than uninfected crayfish, suggesting that the reduced feeding observed in short-term experiments does not occur over longer timescales. However, in support of the second hypothesis, when predatory fish were present, infected crayfish ate more macroinvertebrates than did uninfected crayfish, likely due to increased boldness. We also observed a

  15. Parasites alter freshwater communities in mesocosms by modifying invasive crayfish behavior.

    PubMed

    Reisinger, Lindsey S; Lodge, David M

    2016-06-01

    Parasites can alter communities by reducing densities of keystone hosts, but few studies have examined how trait-mediated indirect effects of parasites can alter ecological communities. We test how trematode parasites (Microphallus spp.) that affect invasive crayfish (Orconectes rusticus) behavior alter how crayfish impact lake littoral communities. O. rusticus drive community composition in north temperate lakes, and predatory fish can reduce crayfish activity and feeding. In laboratory studies, Microphallus parasites also alter O. rusticus behavior: infected O. rusticus eat fewer macroinvertebrates and are bolder near predatory fish than uninfected individuals. We used a 2 x 2 factorial experiment to test how predatory fish and parasites affect O. rusticus impacts in large mesocosms over 4 weeks. We predicted (1) that when predators were absent, infected crayfish would have lower impacts than uninfected crayfish on macrophytes and macroinvertebrates (as well as reduced growth and higher mortality). However, (2) when predators were present but unable to consume crayfish, infected crayfish would have greater impacts (as well as greater growth and lower mortality) than uninfected crayfish because of increased boldness. Because of its effect on crayfish feeding behavior, we also predicted (3) that infection would alter macrophyte and macroinvertebrate community composition. In contrast to our first hypothesis, we found that infected and uninfected crayfish had similar impacts on lower trophic levels when predators were absent. Across all treatments, infected crayfish were more likely to be outside shelters and had greater growth than uninfected crayfish, suggesting that the reduced feeding observed in short-term experiments does not occur over longer timescales. However, in support of the second hypothesis, when predatory fish were present, infected crayfish ate more macroinvertebrates than did uninfected crayfish, likely due to increased boldness. We also observed a

  16. Juvenile Firesetting.

    PubMed

    Peters, Brittany; Freeman, Bradley

    2016-01-01

    Juvenile firesetting is a significant cause of morbidity and mortality in the United States. Male gender, substance use, history of maltreatment, interest in fire, and psychiatric illness are commonly reported risk factors. Interventions that have been shown to be effective in juveniles who set fires include cognitive behavior therapy and educational interventions, whereas satiation has not been shown to be an effective intervention. Forensic assessments can assist the legal community in adjudicating youth with effective interventions. Future studies should focus on consistent assessment and outcome measures to create more evidence for directing evaluation and treatment of juvenile firesetters. PMID:26593122

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

    PubMed Central

    Franke, Robert; Hoerstgen-Schwark, Gabriele

    2013-01-01

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

  18. Annual variability in reproduction of the white-clawed crayfish ( Austropotamobius pallipes): implications for survival

    NASA Astrophysics Data System (ADS)

    Neveu, André

    2007-07-01

    The white-clawed crayfish is generally considered as an endangered species and it is necessary to estimate the functioning quality in residual population patches, particularly reproduction. For six consecutive years, a population was studied in a forest brook in Normandy (France). The size, state of maturity, density and egg number in mature females as well juvenile density were measured. The proportion of mature females varied between 16% and 31% among all 1078 females (>1+ year old). The number of both ovocytes and eggs laid are correlated with the size of females and the majority of the mature females expel all ripe ovocytes. In June, the potential hatchlings number remains correlated with the female size and this relationship evolves from year to year. The females are more numerous downstream associated with greater structural complexity of the substrate: at laying, the potential egg stock is on average 45.8 m -2 (upstream: 22.2 m -2) and at hatching 15.5 m -2 (upstream: 5.8 m -2). The losses are due above all to reduction of berried females and the smaller females tend to lose eggs more easily than the larger ones. The survival of juveniles during the first summer of independence is greater upstream. Nevertheless, it corresponds to a stable rate of 12% from potential eggs. Some results show a regulation process with an optimum density. The clogging of substrate can reduce greatly juvenile survival and in some years the upstream site can be considered as an ecological trap. The downstream site seems to be the most suitable habitat for conservation purposes, in spite of higher individual egg load upstream. For the future of the species, population functioning must be studied at the scale of the whole population patch. Meanwhile the upstream biotic capacity may be ameliorated by an increase in number of shelters.

  19. Juvenile Prostitution.

    ERIC Educational Resources Information Center

    Csapo, Marg

    1986-01-01

    Recent research and Canadian government committee reports concerning juvenile prostitution are reviewed. Proposals are made in the realms of law and social policy; and existing programs are described. (DB)

  20. Impacts of Invasive Rusty Crayfish on Stream Ecosystems of the Upper Midwestern U.S.

    NASA Astrophysics Data System (ADS)

    Bobeldyk, A. M.; Lamberti, G. A.

    2005-05-01

    Invasive species can have detrimental effects on structural characteristics of freshwater ecosystems, but relatively few studies have assessed ecosystem-level impacts of invasive species in streams. We studied the effects of invasive rusty crayfish (Orconectes rusticus) on detritus processing and invertebrate and fish abundance in northern Wisconsin and Michigan, USA, streams. We hypothesized that rusty crayfish would increase the rate of detritus processing and reduce fish and invertebrate abundance due to their aggressiveness and competitive superiority for food and habitat. We measured sugar maple (Acer saccharum) decomposition rates in three reaches of a stream with differing densities of rusty crayfish, high (5.05/m2), intermediate (2.27/m2), and none (0/m2) using leaf bags excluding crayfish and open bags allowing crayfish access. We found that open bags decayed significantly faster (k=0.143) than crayfish excluded bags at all sites (k=0.079) (p=0.0005). The reach lacking crayfish had significantly higher densities of invertebrates (p=0.005). We also surveyed an additional 7 streams that contained or lacked rusty crayfish and found significantly higher fish abundance (p=0.019) and biomass (p=0.001) in streams lacking rusty crayfish. Rusty crayfish appear to indirectly affect detritus processing via negative effects on benthic invertebrates, and may have larger-scale impacts on fishes across streams.

  1. Assessing potential abiotic and biotic complications of crayfish-induced gravel transport in experimental streams

    NASA Astrophysics Data System (ADS)

    Statzner, Bernhard; Peltret, Odile

    2006-03-01

    Biogeomorphology adds the element "biological dynamics" (of populations or communities) to chemical and physical geomorphic factors and thus complicates the framework of geomorphic processes. Such biological complications of the animal-induced transport of solids in streams should be particularly important in crayfish, as crayfish affect this transport through their overall activity and intraspecific aggression levels, which could be modified by shelter availability or the establishment of dominance hierarchies among individuals not knowing each other. Using experimental streams, we tested these hypotheses by measuring how shelter availability or residential crayfish group invasion by unknown individuals affected the impact of the crayfish Orconectes limosus on the (i) transport of gravel at baseflow (during 12 experimental days); (ii) sediment surface characteristics (after 12 days); and (iii) critical shear stress causing incipient gravel motion during simulated floods (after 12 days). The two potentially important factors shelter availability or residential group invasion negligibly affected the crayfish impact on gravel sediments, suggesting that habitat unfamiliarity (a third potentially important factor affecting crayfish activity) should increase the crayfish-induced sediment transport. Because habitat unfamiliarity is associated with sporadic long-distance migrations of a few crayfish individuals, this third factor should play a minor role in real streams, where crayfish biomass should be a key factor in relations with crayfish effects on sediments. Therefore, we combined the results of this study with those of previous crayfish experiments to assess how crayfish biomass could serve in modelling the gravel transport. Crayfish biomass explained 47% of the variability in the baseflow gravel transport and, in combination with the coefficient of variation of the bed elevation and algal cover, 72% of the variability in the critical gravel shear stress. These

  2. Divergent responses of exposed and naive Pacific tree frog tadpoles to invasive predatory crayfish.

    PubMed

    Pease, Katherine M; Wayne, Robert K

    2014-01-01

    Invasive predators can devastate native species and ecosystems. However, native species may be able to coexist with invasive predators through a variety of mechanisms, such as changes in morphology or behavior due to a plastic response or selection on fixed anti-predator traits. We examined whether exposed and naive populations of Pacific tree frog tadpoles (Pseudacris regilla) display divergent morphological and behavioral traits in response to the invasive predatory red swamp crayfish (Procambarus clarkii). Tadpoles were collected from three study streams with and three without crayfish, in the Santa Monica Mountains of Southern California. We analyzed tadpole morphology and tested anti-predator behavior and survival in the laboratory. Tadpoles from streams with crayfish had shallower, narrower tails than tadpoles from streams without crayfish. Tadpoles from streams with and without crayfish were less active after exposure to crayfish chemical cues. The divergent morphology of naive and exposed tadpoles is consistent with tadpoles exhibiting a plastic response to crayfish or undergoing selection from crayfish predation. In laboratory predation experiments, we found no difference in survival between tadpoles from streams with and without crayfish but tadpoles that survived predation had deeper tail muscles than those that were killed or injured. Our results suggest that deeper tails are advantageous in the presence of crayfish, yet tadpoles from crayfish streams had shallower tails than those from crayfish-free streams. Shallower tails may have an alternative unmeasured advantage or there may be a physiological constraint to developing deeper tails in the wild. These results highlight the ability of a native frog to respond to an invasive predatory crayfish, potentially allowing for coexistence.

  3. Crayfish Behavior: Observing Arthropods to Learn about Science & Scientific Inquiry

    ERIC Educational Resources Information Center

    Rop, Charles J.

    2010-01-01

    This is a set of animal behavior investigations in which students will practice scientific inquiry as they observe crayfish, ask questions, and discuss territoriality, social interactions, and other behaviors. In doing this, they hone their skills of observation, learn to record and analyze data, control for variables, write hypotheses, make…

  4. Crayfish Investigations: Inquiry in Action for Grades 4-8

    ERIC Educational Resources Information Center

    Martin-Hansen, Lisa M.

    2005-01-01

    The author, an elementary school teacher, describes a way of incorporating an inquiry approach to teaching by refining a crayfish unit originally found in an ESS (Elementary Science Study) module. She used a "coupled-inquiry" approach, a combination of guided-inquiry and open-inquiry, with an application used for assessment purposes. In five or…

  5. Modeling the Process of Science: Investigating Sexual Dimorphism in Crayfish.

    ERIC Educational Resources Information Center

    Mullen, Dennis M.; Rutledge, Michael L.; Swain, Sarah H.

    2003-01-01

    Describes a scientific investigation of sexual dimorphism with regard to chela size in crayfish in which students utilize the skills, tools, and techniques associated with the formulation and testing of scientific hypotheses. Indicates that students find the investigation effective in aiding their understanding of fundamental aspects of scientific…

  6. The Spectral Sensitivity of Crayfish and Lobster Vision

    PubMed Central

    Kennedy, Donald; Bruno, Merle S.

    1961-01-01

    (1) The spectral sensitivity function for the compound eye of the crayfish has been determined by recording the retinal action potentials elicited by monochromatic stimuli. Its peak lies at approximately 570 mµ. (2) Similar measurements made on lobster eyes yield functions with maxima in the region of 520 to 525 mµ, which agree well with the absorption spectrum of lobster rhodopsin if minor allowances are made for distortion by known screening pigments. (3) The crayfish sensitivity function, since it is unaffected by selective monochromatic light adaptation, must be determined by a single photosensitive pigment. The absorption maximum of this pigment may be inferred with reasonable accuracy from the sensitivity data. (4) The visual pigment of the crayfish thus has its maximum absorption displaced by 50 to 60 mµ towards the red end of the spectrum from that of the lobster and other marine crustacea. This shift parallels that found in both rod and cone pigments between fresh water and marine vertebrates. In the crayfish, however, an altered protein is responsible for the shift and not a new carotenoid chromophore as in the vertebrates. (5) The existence of this situation in a new group of animals (with photoreceptors which have been evolved independently from those of vertebrates) strengthens the view that there may be strong selection for long wavelength visual sensitivity in fresh water. PMID:13752502

  7. The spectral sensitivity of crayfish and lobster vision.

    PubMed

    KENNEDY, D; BRUNO, M S

    1961-07-01

    (1) The spectral sensitivity function for the compound eye of the crayfish has been determined by recording the retinal action potentials elicited by monochromatic stimuli. Its peak lies at approximately 570 mmicro. (2) Similar measurements made on lobster eyes yield functions with maxima in the region of 520 to 525 mmicro, which agree well with the absorption spectrum of lobster rhodopsin if minor allowances are made for distortion by known screening pigments. (3) The crayfish sensitivity function, since it is unaffected by selective monochromatic light adaptation, must be determined by a single photosensitive pigment. The absorption maximum of this pigment may be inferred with reasonable accuracy from the sensitivity data. (4) The visual pigment of the crayfish thus has its maximum absorption displaced by 50 to 60 mmicro towards the red end of the spectrum from that of the lobster and other marine crustacea. This shift parallels that found in both rod and cone pigments between fresh water and marine vertebrates. In the crayfish, however, an altered protein is responsible for the shift and not a new carotenoid chromophore as in the vertebrates. (5) The existence of this situation in a new group of animals (with photoreceptors which have been evolved independently from those of vertebrates) strengthens the view that there may be strong selection for long wavelength visual sensitivity in fresh water.

  8. Waterborne outbreak of tularemia associated with crayfish fishing.

    PubMed Central

    Anda, P.; Segura del Pozo, J.; Díaz García, J. M.; Escudero, R.; García Peña, F. J.; López Velasco, M. C.; Sellek, R. E.; Jiménez Chillarón, M. R.; Sánchez Serrano, L. P.; Martínez Navarro, J. F.

    2001-01-01

    In 1997, an outbreak of human tularemia associated with hare-hunting in central Spain affected 585 patients. We describe the identification of Francisella tularensis biovar palaearctica in a second outbreak of ulceroglandular tularemia associated with crayfish (Procambarus clarkii) fishing in a contaminated freshwater stream distant from the hare-associated outbreak. The second outbreak occurred 1 year after the first. PMID:11485678

  9. Juvenile idiopathic arthritis

    MedlinePlus

    Juvenile rheumatoid arthritis (JRA); Juvenile chronic polyarthritis; Still disease; Juvenile spondyloarthritis ... The cause of juvenile idiopathic arthritis (JIA) is not known. It is thought to be an autoimmune illness . This means the body attacks ...

  10. Application of morphologic burrow architects: lungfish or crayfish?

    USGS Publications Warehouse

    Hasiotis, Stephen T.; Mitchell, Charles E.; Dubiel, Russell R.

    1993-01-01

    A methodology for trace fossil identification using burrowing signatures is tested by evaluating ancient and modern lungfish and crayfish burrows and comparing them to previously undescribed burrows in a stratigraphic interval thought to contain both lungfish and crayfish burrows. Permian burrows that bear skeletal remains of the lungfish Gnathorhiza, from museum collections, were evaluated to identify unique burrow morphologies that could be used to distinguish lungfish from crayfish burrows when fossil remains are absent. The lungfish burrows were evaluated for details of the burrowing mechanism preserved in the burrow morphologies together forming burrowing signatures and were compared to new burrows in the Chinle Formation of western Colorado to test the methodology of using burrow signatures to identify unknown burrows. Permian lungfish aestivation burrows show simple, nearly vertical, unbranched architectures and relatively smooth surficial morphologies with characteristic quasi‐horizontal striae on the burrow walls and vertical striae on the bulbous terminus. Burrow lengths do not exceed 0.5 m. In contrast, modern and ancient crayfish burrows exhibit simple to highly complex architectures with highly textured surficial morphologies. Burrow lengths may reach 4 to 5 m. Burrow morphologies unlike those identified in Gnathorhiza aestivation burrows were found in four burrow groups from museum collections. Two of these groups exhibit simple architectures and horizontal striae that were greater in sinuosity and magnitude, respectively. One of these burrows contains the remains of Lysorophus, but the burrow surface reveals no reliable surficial characteristics. It is not clear whether Lysorophus truly burrowed or merely occupied a pre‐existing structure. The other two groups exhibit surficial morphologies similar to those found on modern and ancient crayfish burrows and may provide evidence of freshwater crayfish in the Permian. Burrows from the Upper Triassic

  11. 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.

  12. BRAIN PHOTORECEPTOR PATHWAYS CONTRIBUTING TO CIRCADIAN RHYTHMICITY IN CRAYFISH

    PubMed Central

    Sullivan, Jeremy M.; Genco, Maria C.; Marlow, Elizabeth D.; Benton, Jeanne L.; Beltz, Barbara S.; Sandeman, David C.

    2011-01-01

    Freshwater crayfish have three known photoreceptive systems: the compound eyes, extraretinal brain photoreceptors, and caudal photoreceptors. The primary goal of the work described here was to explore the contribution of the brain photoreceptors to circadian locomotory activity and define some of the underlying neural pathways. Immunocytochemical studies of the brain photoreceptors in the parastacid (southern hemisphere) crayfish Cherax destructor reveal their expression of the blue light-sensitive photopigment cryptochrome and the neurotransmitter histamine. The brain photo-receptors project to two small protocerebral neuropils, the brain photoreceptor neuropils (BPNs), where they terminate among fibers expressing the neuropeptide pigment-dispersing hormone (PDH), a signaling molecule in arthropod circadian systems. Comparable pathways are also described in the astacid (northern hemisphere) crayfish Procambarus clarkii. Despite exhibiting markedly different diurnal locomotor activity rhythms, removal of the compound eyes and caudal photoreceptors in both C. destructor and P. clarkii (leaving the brain photoreceptors intact) does not abolish the normal light/dark activity cycle in either species, nor prevent the entrainment of their activity cycles to phase shifts of the light/dark period. These results suggest, therefore, that crayfish brain photoreceptors are sufficient for the entrainment of loco-motor activity rhythms to photic stimuli, and that they can act in the absence of the compound eyes and caudal photoreceptors. We also demonstrate that the intensity of PDH expression in the BPNs varies in phase with the locomotor activity rhythm of both crayfish species. Together, these findings suggest that the brain photoreceptor cells can function as extraretinal circadian photoreceptors and that the BPN represents part of an entrainment pathway synchronizing locomotor activity to environmental light/dark cycles, and implicating the neuropeptide PDH in these

  13. Crayfish (Orconectes virilis) feeding on young lake trout (Salvelinus namaycush): effect of rock size

    USGS Publications Warehouse

    Savino, Jacqueline F.; Miller, John E.

    1991-01-01

    In laboratory studies, we quantified predation rates of crayfish (Orconectes virilis) on the eggs and sac fry of lake trout (Salvelinus namaycush) and a surrogate species, rainbow trout (Oncorhynchus mvkiss), dispersed among different sized substrates (bare bottom, gravel, cobble, large rocks). Predation was most severe when no rocks were present. Feeding rate then decreased as the substrate changed from large rocks to cobble to gravel. Crayfish predation rate did not change with prey type—rainbow trout and lake trout eggs or sac fry. Crayfish foraging in large tanks containing cobble averaged about two eggs or sac fry per day. In most instances, crayfish would have little impact on lake trout egg survival. Only in lake trout spawning grounds with relatively low egg densities, large crayfish populations, and cobble or large rock substrate, would crayfish be expected to have some impact on lake trout egg survival.

  14. Preventing overexploitation in a mutualism: partner regulation in the crayfish-branchiobdellid symbiosis.

    PubMed

    Farrell, Kaitlin J; Creed, Robert P; Brown, Bryan L

    2014-02-01

    For a symbiosis to be a mutualism, benefits received must exceed costs incurred for both partners. Partners can prevent costly overexploitation through behaviors that moderate interactions with the other symbiont. In a symbiosis between crayfish and branchiobdellidan annelids, the worms can increase crayfish survival and growth by removing fouling material from the gills. However, overexploitation by the worms is possible and results in damage to host gills. We used behavioral observations to assess the degree to which two species of crayfish (Cambarus chasmodactylus and Orconectes cristavarius) use grooming to moderate their interaction with branchiobdellids. We found that grooming could effectively reduce worm numbers, and the proportion of total grooming directed at worms differed between crayfish species and as a function of worm number. O. cristavarius increased grooming in response to the addition of a single worm, while C. chasmodactylus only increased grooming in response to ten worms. These differences in the number of worms that trigger grooming behavior reflect differences between crayfish species in field settings. We also assessed whether antibacterial compounds in circulating crayfish hemolymph could limit bacterial gill fouling. O. cristavarius hemolymph inhibited some test bacteria more effectively than C. chasmodactylus did. Differences in the antibacterial properties of crayfish hemolymph may therefore help explain differences in both worm-directed grooming and worm loads in the field. We conclude that crayfish can use grooming to reduce worm numbers, which could lower the potential for gill damage, and that the level of grooming varies between crayfish species.

  15. THE UPTAKE OF INORGANIC ELECTROLYTES BY THE CRAYFISH

    PubMed Central

    Maluf, N. S. Rustum

    1940-01-01

    1. Reasons are given for believing that the uptake of Na+, Cl-, and NaCl by the crayfish occurs through the gills. 2. A crayfish in fresh water, with a Cl concentration of about 0.2 mEq./l., can) by active Cl absorption, compensate entirely for Cl lost in the urine. 3. The carbonic anhydrase activity of the gills is markedly higher than that of other tissues of the crayfish, but the equivalent CO2 output of the crayfish is far in excess of the equivalent Cl absorption per unit time and weight and thus fails to warrant the supposition that Cl absorption is of respiratory importance. 4. The carbonic anhydrase activity of the soft integument of the lobster, before and after molting, and of the hypodermis of the hard-cuticled animal is almost identical and of the same order as that of other tissues of the lobster. 5. The concentration of the electrolytes was about 7.5 mEq./l.; i.e., considerably lower than in the blood of the crayfish. Cl- can be taken up independently of the complementary cation. Na+ can be taken up independently of the complementary anion. K+ and SO4= are not taken up at all. In pure NaCl, the Na+ and Cl- are absorbed evidently largely together. Ca++ is absorbed only in newly molted animals and in animals preparing to molt but is not absorbed by hard-cuticled animals not preparing to molt. Ca++ is taken up independently of Cl- in pure CaCl2. 6. Newly molted animals absorb Ca++ at a rate exceeding that of the absorption of other absorbable ions (Na+ and Cl-) in the same equivalent concentration. 7. A crayfish utilizes the Ca++ in fresh water in the calcification of its cuticle. Since the animal does not swallow water, the Ca++ must enter through the exterior. Reasons are given for believing that, unlike Na+ and Cl-, Ca++ is absorbed directly from the exterior by the integument and does not enter the body through the gills. 8. During molting, only about 4 per cent of the raw ash and 2.3 per cent of the organic material of the old cuticle is resorbed

  16. Juvenile Spondyloarthritis

    PubMed Central

    Gmuca, Sabrina; Weiss, Pamela F.

    2015-01-01

    Purpose of review To provide a comprehensive update of the pathogenesis, diagnostic imaging, treatments, and disease activity measurements of juvenile spondyloarthritis (JSpA). Recent findings Genetic and microbiome studies have provided new information regarding possible pathogenesis of JSpA. Recent work suggests that children with JSpA have decreased thresholds for pain in comparison to healthy children. Additionally, pain on physical examination and abnormalities on ultrasound of the entheses are not well correlated. Treatment guidelines for juvenile arthritis, including JSpA, were published by the American College of Rheumatology and are based on active joint count and presence of sacroiliitis. Recent studies have established the efficacy of tumor necrosis factor inhibitors in the symptomatic treatment of axial disease, though their efficacy for halting progression of structural damage is less clear. Newly developed disease activity measures for JSpA include the Juvenile Arthritis Disease Activity Score and the JSpA Disease Activity index. In comparison to other categories of juvenile arthritis, children with JSpA are less likely to attain and sustain inactive disease. Summary Further microbiome and genetic research may help elucidate JSpA pathogenesis. More randomized therapeutic trials are needed and the advent of new composite disease activity measurement tools will hopefully allow for the design of these greatly needed trials. PMID:26002028

  17. A mechanism for neuronal coincidence revealed in the crayfish antennule

    PubMed Central

    Mellon, DeForest; Christison-Lagay, Kate

    2008-01-01

    Startle reflexes employ specialized neuronal circuits and synaptic features for rapid transmission of information from sense organs to responding muscles. Successful excitation of these pathways requires the coincidence of sensory input at central synaptic contacts with giant fiber targets. Here we describe a pathway feature in the crayfish tailflip reflex: A position-dependent linear gradation in sensory axonal conduction velocities that can ensure the coincident arrival of impulses from near-field hydrodynamic sensilla along the crayfish antennules at their synaptic contacts with central nervous elements that drive startle behavior. This provides a previously unexplored mechanism to ensure optimum responses to sudden threatening stimuli. Preliminary findings indicate that axons supplying distally located sensilla increase their diameters at least ten-fold along the antennular flagella and raise the possibility that more modest, graduated, diameter changes in axons originating from progressively more proximal sensilla along the antennule underlie the observed modifications in axonal conduction velocity. PMID:18794524

  18. Invasive Crayfish Threaten the Development of Submerged Macrophytes in Lake Restoration

    PubMed Central

    van der Wal, Jessica E. M.; Dorenbosch, Martijn; Immers, Anne K.; Vidal Forteza, Constanza; Geurts, Jeroen J. M.; Peeters, Edwin T. H. M.; Koese, Bram; Bakker, Elisabeth S.

    2013-01-01

    Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous exotic crayfish. We hypothesize that invasive crayfish pose a novel constraint on the regeneration of submerged macrophytes in restored lakes and may jeopardize restoration efforts. We experimentally investigated whether the invasive crayfish (Procambarus clarkii Girard) affects submerged macrophyte development in a Dutch peat lake where these crayfish are expanding rapidly. Seemingly favourable abiotic conditions for macrophyte growth existed in two 0.5 ha lake enclosures, which provided shelter and reduced turbidity, and in one lake enclosure iron was added to reduce internal nutrient loading, but macrophytes did not emerge. We transplanted three submerged macrophyte species in a full factorial exclosure experiment, where we separated the effect of crayfish from large vertebrates using different mesh sizes combined with a caging treatment stocked with crayfish only. The three transplanted macrophytes grew rapidly when protected from grazing in both lake enclosures, demonstrating that abiotic conditions for growth were suitable. Crayfish strongly reduced biomass and survival of all three macrophyte species while waterfowl and fish had no additive effects. Gut contents showed that crayfish were mostly carnivorous, but also consumed macrophytes. We show that P. clarkii strongly inhibit macrophyte development once favourable abiotic conditions for macrophyte growth are restored. Therefore, expansion of invasive crayfish poses a novel threat to the restoration of shallow water bodies in north-western Europe. Prevention of introduction and spread of crayfish is urgent, as management of invasive crayfish populations is very difficult. PMID:24205271

  19. Atrazine exposure affects the ability of crayfish (Orconectes rusticus) to localize a food odor source.

    PubMed

    Belanger, Rachelle M; Peters, Tyler J; Sabhapathy, Gita S; Khan, Sana; Katta, Juhi; Abraham, Noor K

    2015-05-01

    Environmental pollutants, found in aquatic ecosystems, have been shown to have an effect on olfactory-mediated behaviors including feeding, mate attraction, and other important social behaviors. Crayfish are polytrophic, meaning that they feed on and become prey for all levels of the aquatic food web as well as are also important for the transfer of energy between benthic and terrestrial food webs. Because crayfish are a keystone species, it is important to investigate any factors that may affect their population size. Crayfish are active at night and rely heavily on their sensory appendages (e.g., antennulues, maxillipeds, and pereopods) to localize food sources. In this experiment, we investigated the effects of atrazine (ATR) exposure on the chemosensory responses of male and female crayfish to food odors. We exposed crayfish to environmentally relevant, sublethal levels of ATR [80 ppb (µg/L)] for 72 h and then examined the behavioral responses of both ATR-treated and control crayfish to food odor delivered from one end of a test arena. We used Noldus Ethovision XT software to measure odor localization and locomotory behaviors of crayfish in response to food (fish) odor. We found that control crayfish spent more time in the proximal region of the test arena and at the odor source compared with ATR-treated crayfish. Furthermore, there were no differences in the time spent moving and not moving, total distance travelled in the tank, and walking speed (cm/s) when control and ATR-treated crayfish were compared. Overall, this indicates that acute ATR exposure alters chemosensory abilities of crayfish, whereas overall motor function remains unchanged.

  20. Invasive crayfish threaten the development of submerged macrophytes in lake restoration.

    PubMed

    van der Wal, Jessica E M; Dorenbosch, Martijn; Immers, Anne K; Vidal Forteza, Constanza; Geurts, Jeroen J M; Peeters, Edwin T H M; Koese, Bram; Bakker, Elisabeth S

    2013-01-01

    Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous exotic crayfish. We hypothesize that invasive crayfish pose a novel constraint on the regeneration of submerged macrophytes in restored lakes and may jeopardize restoration efforts. We experimentally investigated whether the invasive crayfish (Procambarus clarkii Girard) affects submerged macrophyte development in a Dutch peat lake where these crayfish are expanding rapidly. Seemingly favourable abiotic conditions for macrophyte growth existed in two 0.5 ha lake enclosures, which provided shelter and reduced turbidity, and in one lake enclosure iron was added to reduce internal nutrient loading, but macrophytes did not emerge. We transplanted three submerged macrophyte species in a full factorial exclosure experiment, where we separated the effect of crayfish from large vertebrates using different mesh sizes combined with a caging treatment stocked with crayfish only. The three transplanted macrophytes grew rapidly when protected from grazing in both lake enclosures, demonstrating that abiotic conditions for growth were suitable. Crayfish strongly reduced biomass and survival of all three macrophyte species while waterfowl and fish had no additive effects. Gut contents showed that crayfish were mostly carnivorous, but also consumed macrophytes. We show that P. clarkii strongly inhibit macrophyte development once favourable abiotic conditions for macrophyte growth are restored. Therefore, expansion of invasive crayfish poses a novel threat to the restoration of shallow water bodies in north-western Europe. Prevention of introduction and spread of crayfish is urgent, as management of invasive crayfish populations is very difficult.

  1. Interlocking of chelae is a key factor for dominance hierarchy formation in crayfish.

    PubMed

    Ueno, Ryusuke; Nagayama, Toshiki

    2012-08-15

    We characterized the role of chelae during agonistic encounters of the crayfish Procambarus clarkii. Physical asymmetries in body length, body mass and chelae size were directly related to dominance hierarchy formation. More than 80% of winning crayfish had longer body and chelae lengths, and winners were usually heavier in body mass, even if their differences were less than 3% compared with losing opponents. In mismatched pairings, large crayfish with short chelae were beaten by small crayfish with large chelae. Three physical elements of body length, body mass and chelae length equally affected the outcome of agonistic bouts. Chelae restriction, in which chelae were tightly closed using rubber bands, affected the outcome of agonistic bouts between large and small crayfish. Before chelae restriction, large crayfish won in all pairings. Following chelae restriction for at least 30 days from the first encounters, the winning rate of large crayfish that were previous winners decreased significantly in the second encounters against the same opponents that were previous losers. The handicap of chelae restriction significantly prolonged the time to formation of the winner-loser relationship. Individual fights escalated during agonistic bouts between large crayfish with one chela restricted and small crayfish with intact chelae, whereas the number of fights increased but the duration of individual fights did not increase in large crayfish with both chelae restricted. Furthermore, when the chelae of both large and small crayfish were disabled, the dominance order was frequently not formed during 30 min of agonistic bouts. Preventing chelae from interlocking prevented escalation of agonistic bouts. We show that interlocking of chelae acted as a key factor for the formation of dominance hierarchy.

  2. Effects of climate change, invasive species, and disease on the distribution of native European crayfishes.

    PubMed

    Capinha, César; Larson, Eric R; Tricarico, Elena; Olden, Julian D; Gherardi, Francesca

    2013-08-01

    Climate change will require species to adapt to new conditions or follow preferred climates to higher latitudes or elevations, but many dispersal-limited freshwater species may be unable to move due to barriers imposed by watershed boundaries. In addition, invasive nonnative species may expand into new regions under future climate conditions and contribute to the decline of native species. We evaluated future distributions for the threatened European crayfish fauna in response to climate change, watershed boundaries, and the spread of invasive crayfishes, which transmit the crayfish plague, a lethal disease for native European crayfishes. We used climate projections from general circulation models and statistical models based on Mahalanobis distance to predict climate-suitable regions for native and invasive crayfishes in the middle and at the end of the 21st century. We identified these suitable regions as accessible or inaccessible on the basis of major watershed boundaries and present occurrences and evaluated potential future overlap with 3 invasive North American crayfishes. Climate-suitable areas decreased for native crayfishes by 19% to 72%, and the majority of future suitable areas for most of these species were inaccessible relative to native and current distributions. Overlap with invasive crayfish plague-transmitting species was predicted to increase. Some native crayfish species (e.g., noble crayfish [Astacus astacus]) had no future refugia that were unsuitable for the modeled nonnative species. Our results emphasize the importance of preventing additional introductions and spread of invasive crayfishes in Europe to minimize interactions between the multiple stressors of climate change and invasive species, while suggesting candidate regions for the debatable management option of assisted colonization.

  3. Acute Atrazine Exposure has Lasting Effects on Chemosensory Responses to Food Odors in Crayfish (Orconectes virilis).

    PubMed

    Belanger, Rachelle M; Mooney, Lauren N; Nguyen, Hung M; Abraham, Noor K; Peters, Tyler J; Kana, Maria A; May, Lauren A

    2016-02-01

    The herbicide atrazine is known to impact negatively olfactory-mediated behaviors in aquatic animals. We have shown that atrazine exposure has deleterious effects on olfactory-mediated behavioral responses to food odors in crayfish; however, recovery of chemosensory abilities post-atrazine exposure has not been investigated. We examined whether crayfish (Orconectes virilis) recovered chemosensory abilities after a 96-h exposure to sublethal, environmentally relevant concentrations of 80 ppb (µg/L) atrazine. Following treatment, we analyzed the ability of the crayfish to locate a food source using a Y-maze with one arm containing fish-flavored gelatin and the other containing unflavored gelatin. We compared the time spent in the food arm of the Y-maze, near the food source, as well as moving and walking speed of control and atrazine-treated crayfish. We also compared the number of crayfish that handled the food source and the amount of food consumed. Following 24-, 48-, and 72-h recovery periods in fresh water, behavioral trials were repeated to determine if there was any observable recovery of chemosensory-mediated behaviors. Atrazine-treated crayfish spent less time in the food arm, at the odor source, and were less successful at finding the food odor source than control crayfish for all times tested. Additionally, atrazine-treated crayfish consumed less fish-flavored than control crayfish; however, treatment did not affect locomotion. Overall, we found that crayfish are not able to recover chemosensory abilities 72 h post-atrazine exposure. Because crayfish rely heavily on their chemosensory abilities to acquire food, the negative impacts of atrazine exposure could affect population size in areas where atrazine is heavily applied.

  4. Comparing the ecological impacts of native and invasive crayfish: could native species' translocation do more harm than good?

    PubMed

    James, J; Slater, F M; Vaughan, I P; Young, K A; Cable, J

    2015-05-01

    Biological invasions are a principal threat to global biodiversity. Omnivores, such as crayfish, are among the most important groups of invaders. Their introduction often results in biodiversity loss, particularly of their native counterparts. Managed relocations of native crayfish from areas under threat from invasive crayfish into isolated 'ark sites' are sometimes suggested as a conservation strategy for native crayfish; however, such relocations may have unintended detrimental consequences for the recipient ecosystem. Despite this, there have been few attempts to quantify the relative impacts of native and invasive crayfish on aquatic ecosystems. To address this deficiency we conducted a meta-analysis on the effects of native and invasive crayfish on nine ecosystem components: decomposition rate, primary productivity, plant biomass, invertebrate density, biomass and diversity, fish biomass and refuge use, and amphibian larval survival. Native and invasive crayfish significantly reduced invertebrate density and biomass, fish biomass and amphibian survival rate and significantly increased decomposition rates. Invasive crayfish also significantly reduced plant biomass and invertebrate diversity and increased primary productivity. These results show that native and invasive crayfish have wide-ranging impacts on aquatic ecosystems that may be exacerbated for invasive species. Subsequent analysis showed that the impacts of invasive crayfish were significantly greater, in comparison to native crayfish, for decomposition and primary productivity but not invertebrate density, biomass and diversity. Overall, our findings reconfirm the ecosystem altering abilities of both native and invasive crayfish, enforcing the need to carefully regulate managed relocations of native species as well as to develop control programs for invasives. PMID:25549809

  5. Comparing the ecological impacts of native and invasive crayfish: could native species' translocation do more harm than good?

    PubMed

    James, J; Slater, F M; Vaughan, I P; Young, K A; Cable, J

    2015-05-01

    Biological invasions are a principal threat to global biodiversity. Omnivores, such as crayfish, are among the most important groups of invaders. Their introduction often results in biodiversity loss, particularly of their native counterparts. Managed relocations of native crayfish from areas under threat from invasive crayfish into isolated 'ark sites' are sometimes suggested as a conservation strategy for native crayfish; however, such relocations may have unintended detrimental consequences for the recipient ecosystem. Despite this, there have been few attempts to quantify the relative impacts of native and invasive crayfish on aquatic ecosystems. To address this deficiency we conducted a meta-analysis on the effects of native and invasive crayfish on nine ecosystem components: decomposition rate, primary productivity, plant biomass, invertebrate density, biomass and diversity, fish biomass and refuge use, and amphibian larval survival. Native and invasive crayfish significantly reduced invertebrate density and biomass, fish biomass and amphibian survival rate and significantly increased decomposition rates. Invasive crayfish also significantly reduced plant biomass and invertebrate diversity and increased primary productivity. These results show that native and invasive crayfish have wide-ranging impacts on aquatic ecosystems that may be exacerbated for invasive species. Subsequent analysis showed that the impacts of invasive crayfish were significantly greater, in comparison to native crayfish, for decomposition and primary productivity but not invertebrate density, biomass and diversity. Overall, our findings reconfirm the ecosystem altering abilities of both native and invasive crayfish, enforcing the need to carefully regulate managed relocations of native species as well as to develop control programs for invasives.

  6. Thermal games in crayfish depend on establishment of social hierarchies.

    PubMed

    Tattersall, Glenn J; Luebbert, Joshua P; LePine, Olivia K; Ormerod, Kiel G; Mercier, A Joffre

    2012-06-01

    An unequal resource distribution is commonly seen in dominance hierarchies, in which the individual with the higher status is more successful in obtaining the resource. One possible resource is preferred temperature. When situations allow, ectotherms regulate their body temperature by behaviourally selecting different environmental conditions, achieving, when possible, a preferred temperature. Using a shuttlebox, the preferred temperature for Procambarus clarkii was determined to be 23.9°C with upper and lower voluntary escape temperatures of 25.9 and 21.8°C, respectively. If this preferred temperature zone (21.8-25.9°C) was valued as a resource, given the choice between a preferred temperature and a non-preferred temperature, crayfish should compete over the preferred temperature, with the dominant individual of dyadic pairs achieving the preferred temperature more often than the subordinate. Using a dual-choice experimental tank, competition over a binary temperature choice between rank-established paired crayfish was determined under both warm and cold challenge conditions (warm vs preferred temperature and cold vs preferred temperature, respectively). In naive pairings, similar levels of competition over the preferred temperature occurred in both warm and cold challenge trials, as predicted by game theory. In established pairings, however, dominant crayfish gained significantly greater access to preferred temperature in both warm and cold challenge conditions. These results demonstrate that crayfish engage in a cost-benefit assessment during their initial agonistic contests over temperature, but as hierarchies mature, these thermal games are decided by the dominant animal gaining primary access to the temperature resource.

  7. Habituation of Backward Escape Swimming in the Marbled Crayfish.

    PubMed

    Kasuya, Azusa; Nagayama, Toshiki

    2016-02-01

    In the present study, we performed behavioral analyses of the habituation of backward escape swimming in the marbled crayfish, Procambarus fallax. Application of rapid mechanical stimulation to the rostrum elicited backward swimming following rapid abdominal flexion of crayfish. Response latency was very short-tens of msec-suggesting that backward swimming is mediated by MG neurons. When stimulation was repeated with 10 sec interstimulus intervals the MG-like tailflip did not occur, as the animals showed habituation. Retention of habituation was rather short, with most animals recovering from habituation within 10 min. Previous experience of habituation was remembered and animals habituated faster during a second series of experiments with similar repetitive stimuli. About half the number of stimulus trials was necessary to habituate in the second test compared to the first test. This promotion of habituation was observed in animals with delay periods of rest within 60 min following the first habituation. After 90 min of rest from the first habitation, animals showed a similar time course for the second habituation. With five stimuli at 15 min interval during 90 min of the rest, trained animals showed rapid habituation, indicating reinforcement of the memory of previous experiments. Crayfish also showed dishabituation when mechanical stimulation was applied to the tail following habituation.

  8. Chronic electromyographic analysis of circadian locomotor activity in crayfish.

    PubMed

    Tomina, Yusuke; Kibayashi, Akihiro; Yoshii, Taishi; Takahata, Masakazu

    2013-07-15

    Animals generally exhibit circadian rhythms of locomotor activity. They initiate locomotor behavior not only reflexively in response to external stimuli but also spontaneously in the absence of any specific stimulus. The neuronal mechanisms underlying circadian locomotor activity can, therefore, be based on the rhythmic changes in either reflexive efficacy or endogenous activity. In crayfish Procambarus clarkii, it can be determined by analyzing electromyographic (EMG) patterns of walking legs whether the walking behavior is initiated reflexively or spontaneously. In this study, we examined quantitatively the leg muscle activity that underlies the locomotor behavior showing circadian rhythms in crayfish. We newly developed a chronic EMG recording system that allowed the animal to freely behave under a tethered condition for more than 10 days. In the LD condition in which the animals exhibited LD entrainment, the rhythmic burst activity of leg muscles for stepping behavior was preceded by non-rhythmic tonic activation that lasted for 1323±488ms when the animal initiated walking. In DD and LL free-running conditions, the pre-burst activation lasted for 1779±31 and 1517±39ms respectively. In the mechanical stimulus-evoked walking, the pre-burst activation ended within 79±6ms. These data suggest that periodic changes in the crayfish locomotor activity under the condition of LD entrainment or free-running are based on activity changes in the spontaneous initiation mechanism of walking behavior rather than those in the sensori-motor pathway connecting mechanoreceptors with leg movements.

  9. Habituation of Backward Escape Swimming in the Marbled Crayfish.

    PubMed

    Kasuya, Azusa; Nagayama, Toshiki

    2016-02-01

    In the present study, we performed behavioral analyses of the habituation of backward escape swimming in the marbled crayfish, Procambarus fallax. Application of rapid mechanical stimulation to the rostrum elicited backward swimming following rapid abdominal flexion of crayfish. Response latency was very short-tens of msec-suggesting that backward swimming is mediated by MG neurons. When stimulation was repeated with 10 sec interstimulus intervals the MG-like tailflip did not occur, as the animals showed habituation. Retention of habituation was rather short, with most animals recovering from habituation within 10 min. Previous experience of habituation was remembered and animals habituated faster during a second series of experiments with similar repetitive stimuli. About half the number of stimulus trials was necessary to habituate in the second test compared to the first test. This promotion of habituation was observed in animals with delay periods of rest within 60 min following the first habituation. After 90 min of rest from the first habitation, animals showed a similar time course for the second habituation. With five stimuli at 15 min interval during 90 min of the rest, trained animals showed rapid habituation, indicating reinforcement of the memory of previous experiments. Crayfish also showed dishabituation when mechanical stimulation was applied to the tail following habituation. PMID:26853863

  10. Uptake and depuration of petroleum hydrocarbons by crayfish

    USGS Publications Warehouse

    Tarshis, I.B.

    1981-01-01

    No differences were noted in the amount of naphthalene uptake (approximately 125 :g) by individual crayfish exposed for 1, 2, or 4 hr at 25?C in open, non-aerated glass jars containing14C-naphthalene-5% of a water-soluble fraction (WSF) of No. 2 fuel oil. The cephalothorax, containing the hepatopancreas (a food absorption organ), showed greater uptake of naphthalene than the tail flesh or tail skeleton of individual crayfish exposed to the oil for 3 hr at 25?C. Crayfish exposed to the oil for 1, 2, or 4 hr and then placed in open, non-aerated containers of oil-free water lost most of the carbon-14 activity during the first 24 hr, with smaller losses occurring at 24 hr intervals up to and including 96 hr. Carbon-14 naphthalene in a 5% WSF of No. 2 fuel oil held in 12 open, non-aerated, oil-free, glass jars for 1, 2, 3, 4, and 5 hr at 25?C showed little volatilization (P > 0.4).

  11. [Juvenile angiofibroma].

    PubMed

    Thuesen, Anne Daugaard; Jakobsen, John; Nepper-Rasmussen, Jørgen

    2005-08-22

    Juvenile angiofibroma is a rare, benign, rich vascular tumor, and approximately one new case is diagnosed in Denmark each year. It sits in the foramen sphenopalatinum and occurs in boys from 14 to 25 years of age. The most frequent initial symptoms are nasal obstruction and epistaxis. Through the years, the treatment of juvenile angiofibroma has included many methods, including surgical excision, electrocoagulation, interstitial or external radiation therapy, cryosurgery, hormone administration and chemotherapy. Radiation, chemotherapy and surgery have proven to be the most effective treatments. The most serious complication has been preoperative bleeding, but since the introduction of preoperative particle embolization the blood loss has been greatly reduced. Today, surgery preceded by embolization is the primary standard treatment. It is important to diagnose the tumor early, when radical surgery is easier and the frequency of recurrence is lower.

  12. Plasticity in fecundity highlights the females' importance in the spiny-cheek crayfish invasion mechanism.

    PubMed

    Pârvulescu, Lucian; Pîrvu, Mălina; Moroşan, Loredana-Giorgiana; Zaharia, Claudia

    2015-12-01

    Invasion is one of the most consequential phenomena affecting the distribution of native species. Few in number of species, European crayfish are losing the competition with introduced North American crayfish. The spiny-cheek crayfish, Orconectes limosus, is an outstanding example, successfully competing against the native narrow-clawed crayfish, Astacus leptodactylus. For four years, we collected data regarding crayfish occurrences, their relative abundance, and the structure of populations in the ongoing colonisation process of O. limosus in the lower Danube. The mature females of both invasive and indigenous crayfish species were analysed with respect to biometry and production of oocytes in relation to the dynamics of invasion. The interspecific comparisons showed no significant differences regarding body size, with an average of approximately 102 mm total length and 31 g wet weight for both species. However, the fecundity of the indigenous species was found to be constant throughout the investigated area, whereas the number of eggs produced by the invasive females was significantly increased at the active front of the invasion. The maximum number of ovarian eggs found was 887 and 1156 in the indigenous species and the invasive species, respectively. We propose the scenario that the invasive species, which carries the deadly crayfish plague, creates an ecological advantage by reducing the populations of indigenous crayfish. Subsequently, the invasive females opportunistically use the available resources to enhance their fecundity, resulting in the acute growth of populations. However, the long-term competitiveness and colonisation success of O. limosus still remain in question.

  13. ZEBRA MUSSEL COLONIZATION OF RUSTY CRAYFISH IN GREEN BAY, LAKE MICHIGAN

    EPA Science Inventory

    In August, 1995 six rusty crayfish colonized with zebra mussels were captured in small-meshed fyke-nets sets set apart as of a fish sampling effort at Peter's Marsh and Long-Tail Point Wetland in lower Green Bay. Mussels colonized virtually all areas of the crayfish bodies, but ...

  14. Temperature regulates circadian rhythms of immune responses in red swamp crayfish Procambarus clarkii.

    PubMed

    Dong, Chaohua; Bai, Suhua; Du, Liqiang

    2015-08-01

    As an ectothermic animal, crayfish immunity and their resistance to pathogen can be significantly affected by environmental factors such as light and temperature. It has been found for a long time that multiple immune parameters of animals and human are circadian-regulated by light-entrained circadian rhythm. Whether temperature also affects the immune rhythm of animals still remains unclear. In the present study, we investigated the effect of temperature cycles on the rhythm of crayfish immunity and their resistance. Survival experiments demonstrated that temperature cycles of 24 °C and 18 °C effectively entrained the circadian rhythm of crayfish resistance to Aeromonas hydrophila in constant dark. After being exposed to temperature cycles, the crayfish injected at different time points exhibited significant difference in resistance to A. hydrophila. Bacterial growth and total hemocyte count (THC) also showed circadian variation in crayfish subjected to temperature cycles, but phenoloxidase (PO) activity didn't show rhythmic change under the same conditions. Quantitative real-time PCR revealed that basal expression of crustin1 and astacidin in crayfish subjected to temperature cycles was circadian-rhythmic, but induced expression by A. hydrophila didn't show the same rhythm. In contrast, crayfish maintained at constant temperature showed completely arrhythmic in bacterial resistance, immune parameters mentioned above and the expression of antimicrobial peptides. The results present here collectively indicated that temperature cycles entrained circadian rhythm of some immune parameters and shaped crayfish resistance to bacteria.

  15. Influence of instream habitat and water quality on aggressive behavior in crayfish of channelized headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many agricultural drainage ditches that border farm fields of the Midwestern United States are degraded headwater streams that possess communities of crayfish. We hypothesized that crayfish communities at sites with low instream habitat diversity and poor water quality would show greater evidence of...

  16. Effectiveness of two commercial rotenone formulations in the eradication of virile crayfish Orconectes virillis

    USGS Publications Warehouse

    Recsetar, Matthew S.; Bonar, Scott A.

    2015-01-01

    The virile or northern crayfish Orconectes virilis is an invasive species throughout much of the USA, damaging aquatic communities where it is introduced. Therefore, identification of effective methods for its eradication from areas in which it is unwanted is important. We studied the effectiveness of two commercial formulations of rotenone, Chem Fish Regular and CFT Legumine, for virile crayfish control. Although both formulations were effective for fish eradication, earlier observations by fisheries managers suggested that the relative effectiveness of the two formulations differs for crayfish. The only noteworthy difference between the formulations is that the former contains a synergist. In our first experiment, we tested each toxicant at the maximum labeled dosage (5 ppm) and found CFT Legumine to be 100% ineffective (0% mortality), while the Chem Fish Regular treatment resulted in 12.5% mortality. After we deemed Chem Fish Regular to be the only toxicant with any effectiveness against virile crayfish, we tested concentrations from 5 to 50 ppm and found 10 times the maximum labeled dosage (50 ppm rotenone) was needed to kill all virile crayfish. Because crayfish burrow and can leave water, and because 100% eradication is usually desired, rotenone applied at the labeled rates will not be effective for crayfish control. However, treating a body of water with CFT Legumine to eradicate invasive fish while leaving desirable crayfish unharmed is possible.

  17. SEASONAL FORAGING BY CHANNEL CATFISH ON TERRESTRIALLY BURROWING CRAYFISH IN A FLOODPLAIN-RIVER ECOSYSTEM

    EPA Science Inventory

    The seasonal use of terrestrially burrowing crayfish as a food item by channel catfish Ictalurus punctatus was studied in channelized and non-channelized sections of the Yockanookany River (Mississippi, USA). During seasonal inundation of the floodplains, the crayfish occupied o...

  18. Fusarium avenaceum causes burn spot disease syndrome in noble crayfish (Astacus astacus).

    PubMed

    Makkonen, J; Jussila, J; Koistinen, L; Paaver, T; Hurt, M; Kokko, H

    2013-06-01

    Burn spot disease has been causing epidemics both in the Estonian mainland and in Saaremaa Island in the threatened noble crayfish (Astacus astacus) stocks. To study the cause of the disease, we isolated several Fusarium spp. from Estonian noble crayfish (A. astacus) populations suffering from burn spot disease syndrome. We first identified fungi directly from melanised cuticle by their ITS sequences. Then we isolated Fusarium spp. from melanised spots of crayfish showing burn spot disease symptoms, such as melanisation and shell erosion, from two different crayfish populations and watercourses in Estonia. The isolates were then identified based on ITS and EF1α-gene sequences. Isolates of Fusarium spp. taken from two separate Estonian noble crayfish populations were used in infection studies. Koch postulates confirmed that the studied agent was causing burn spot disease symptoms including shell erosion in the noble crayfish, which were significantly more severe after molts. After the infection period, an identical Fusarium spp. was re-isolated from carapace lesions and was thus shown to be the disease agent causing burn spot disease syndrome and shell erosion in noble crayfish. Based on GenBank database searches, the isolates causing burn spot disease symptoms were identified as Fusarium avenaceum in mainland Estonia and F. solani in Saaremaa crayfish.

  19. Quisqualate-activated single channel currents in neuromuscular preparations of small and large crayfish.

    PubMed

    Finger, W; Martin, C; Pareto, A

    1988-06-01

    Single channel currents elicited by 1-5 mumol/l quisqualate in neuromuscular preparations in large (greater than 16 month old) and small (1-3 month old) crayfish were recorded by means of the patch-clamp technique. In preparations from large crayfish single channel currents of variable amplitude (-1 to -12 pA) were induced by quisqualate. The mean burst lengths of these currents were tau approximately equal to 1-2 ms. In the opener muscle of the first walking leg and the contractor epimeralis muscle of small crayfish the mean burst lengths of single channel currents evoked by quisqualate were prolonged by a factor of about 4 (tau approximately equal to 5 ms). Moreover, in the opener muscle of the first walking leg of small crayfish single channel currents of small amplitude (-0.5 to -2.5 pA) were preferentially evoked by quisqualate. By contrast, in the contractor epimeralis muscle of small crayfish mainly single channel currents of large amplitude (-10 to -12 pA) were elicited by quisqualate. The results suggest that at the stage of neuromuscular development characterizing the small crayfish, gating properties of excitatory postsynaptic channels are different from those in adult crayfish. Furthermore, the results obtained in the opener muscle of the first walking leg of small crayfish are consistent with those obtained previously by means of the noise analysis technique.

  20. Chronic effects of arsenic on American red crayfish, Procambarus clarkii, exposed to monosodium methanearsonate (MSMA) herbicide

    SciTech Connect

    Naqvi, S.M. ); Flagge, C.T. )

    1990-07-01

    Bioaccumulative and biomagnifying effects of arsenic on crayfish have been reported. However, no work has been done on the chronic effects of this heavy metal on crayfish populations. There is a great concern for MSMA (Monosodium Methanearsonate) herbicide in the vicinity of natural waters due to its high water solubility and bioaccumulative potential. American red crayfish (Procambarus clarkii) account for 98% of the annual crayfish harvest in North America. Those pesticides which have greater water solubility (i.e. MSMA) than other less soluble compounds may cause higher mortalities of aquatic organisms, or cause adverse chronic effects if the non-target animals are sublethally exposed. This work was conducted in the laboratory to assess the possible chronic effects of arsenic on crayfish.

  1. A critical review of freshwater crayfish as amphibian predators: capable consumers of toxic prey?

    PubMed

    Wilson, Natasha J; Williams, Craig R

    2014-05-01

    Consumption of amphibian eggs and larvae by crayfish has been widely reported despite many amphibians being unpalatable and/or toxic to other predators. The aim of this review was to gather information regarding the consumption and/or avoidance of toxic amphibians by these omnivores. We then appraised the extent of toxin consumptive ability in terms of crayfish phylogenetic history so as to speculate as to the evolutionary history of this trait. Reports indicating an ability to tolerate amphibian toxins were collected and reviewed for 12 freshwater crayfish species. In reviewing these, we have established that freshwater crayfish appear to be tolerant of a range of toxic amphibians, often consuming large numbers of eggs and larvae without lethal or apparent sublethal effects. Toxin tolerance was evident within both superfamilies (Astacoidea and Parastacoidea) suggesting that tolerance may be a primitive trait in freshwater crayfish.

  2. Cadmium and lead uptake by Red Swamp crayfish (Procambarus clarkii) of Louisiana

    SciTech Connect

    Naqvi, S.M.; Howell, R.D. )

    1993-08-01

    Environmental contamination by heavy metals such as cadmium and lead is generally reflected by an increase in the tissue residues of aquatic animals. This is also true for fresh-water crayfish as reported by Bagatto and Khan (1987) for Orconectes virilis collected in the vicinity of Canadian smelters. They found a positive correlation between the residues of Cd and Pb in crayfish tissues and the distance from smelters. Stinson and Eaton reported similar findings for another crayfish, Pacifasticus leniusculus, collected from a lake on the West Coast of the US which was receiving urban runoff. Cadmium and lead were more concentrated in the viscera and exoskeleton, respectively. Madigosky et al. (1991) found that Procambarus clarkii collected from roadside drainage ditches of Louisiana contained greater amounts of Cd and Pb than commercially harvested control groups. Lead accumulation has been attributed to the use of farm machinery runoff in agricultural areas and Cd to rubber tires. Cadmium and lead are known to accumulate even in those crayfish where no known contamination can be established, e.g., Dickson et al. (1980) found metal residues in troglobitic crayfish. Accumulation of Pb and Cd in the tissues in laboratory-exposed crayfish of different species has been documented by several investigators. These metals accumulate in exoskeleton, hepatopancreas, gills, antennal glands, mid-gut glands and abdominal muscles of crayfish. Generally, all studies mentioned above report metal uptake by crayfish but have not quantified the amount of metal remaining after the crayfish are transferred to uncontaminated water (depuration). The purpose of this study was to: (1) assess Cd and Pb accumulation in laboratory-exposed male and female P. clarkii (total body wet weight basis), and (2) to determine how much metal is lost when crayfish are transferred to uncontaminated aged tap water. 17 refs., 3 tabs.

  3. Signal crayfish as zoogeomorphic agents: diel patterns of fine sediment suspension in a crayfish-affected river and the implications for fine sediment fluxes and dynamics

    NASA Astrophysics Data System (ADS)

    Rice, Stephen; Johnson, Matthew; Reeds, Jake; Longstaff, Holly; Extence, Chris

    2013-04-01

    The signal crayfish (Pacifasticus leniusculus) is a formidable invasive species that has had a deleterious impact on native freshwater fauna across Europe. We contend that the impact of this animal extends beyond ecology into geomorphology and hypothesise that crayfish are significant agents of fine sediment recruitment and mobilisation, with potentially profound impacts on water quality, substrate quality and fine sediment fluxes. Building on pioneering work by colleagues at Queen Mary University, London this poster considers the role of crayfish in fine sediment suspension in a lowland, gravel-bed river. The hypothesis that nocturnal increases in crayfish activity are associated with a greater frequency of sediment suspension events and increases in ambient turbidity, is tested. Strong diel fluctuations in water turbidity were recorded at several sites on the Brampton Arm of the River Nene in England, a river heavily populated by signal crayfish, during August and September 2012. With the exception of three summer flood events, stage measurements during the same period were essentially flat, ruling out a hydraulic cause for overnight rises in turbidity. Water samples collected at midnight and at midday at one site confirm this diel pattern for suspended sediment concentration. Higher mean turbidity values overnight are associated with an increase in the magnitude and frequency of isolated turbidity spikes or events and this is consistent with crayfish nocturnalism. In particular, we suspect that turbidity events are caused by the construction and maintenenance of burrows and by interactions between crayfish and the river bed while foraging, fighting and avoiding each other. Tying the diel SSC signal directly to crayfish activity proved difficult, but several lines of argument presented here suggest that crayfish are the most likely cause of the diel pattern. These results provide substantial support for the idea that signal crayfish are important zoogeomorphic

  4. Life-history notes on Cambarus hubbsi creaser (Hubbs crayfish) from the South Fork Spring River, Arkansas

    USGS Publications Warehouse

    Larson, E.R.; Magoulick, Daniel D.

    2011-01-01

    Many crayfish species native to the southeastern United States are imperiled due to small range sizes and anthropogenic impacts such as habitat loss and introduction of non-native species. Furthermore, effective management of crayfish is limited by the scarcity of life-history and ecological data for many of these species. We report results of the first life-history study of the crayfish Cambarus hubbsi (Hubbs Crayfish). We collected 466 Hubbs Crayfish from the South Fork Spring River, AR throughout 2006 and recorded carapace lengths, wet weights, indicators of reproductive activity, and number of eggs on ovigerous females. Using length-frequency distributions, we identified four Hubbs Crayfish age classes and evaluated growth rates by plotting size by season (winter, spring, summer, autumn). Male Hubbs Crayfish were more common than females in all seasons except autumn, and males weighed more at equivalent lengths than females. Reproductive activity in Hubbs Crayfish peaked in late winter and spring, and ovigerous females were collected in March, April, and June. Ovigerous females were age II or III and carried few eggs relative to co-occurring crayfish of the genus Orconectes. Compared to these Orconectes species, Hubbs Crayfish is comparatively slow growing, long lived, with low reproductive potential, and as a result may be categorized as a K life-history strategist. Based on this species' life-history strategy and previously documented habitat specificity and taxonomic distinctiveness, Hubbs Crayfish may require monitoring and management attention normally reserved for species with smaller ranges.

  5. Fighting Juvenile Gun Violence. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Sheppard, David; Grant, Heath; Rowe, Wendy; Jacobs, Nancy

    This bulletin describes the Office of Juvenile Justice and Delinquency Prevention's efforts to fight juvenile gun violence. The Office awarded four community demonstration grants to implement "Partnerships To Reduce Juvenile Gun Violence." Partnership goals include increasing the effectiveness of existing strategies by enhancing and coordinating…

  6. Flow cytometric analysis of crayfish haemocytes activated by lipopolysaccharides

    USGS Publications Warehouse

    Cardenas, W.; Dankert, J.R.; Jenkins, J.A.

    2004-01-01

    Lipopolysaccharides (LPS) from Gram-negative bacteria are strong stimulators of white river crayfish, Procambarus zonangulus, haemocytes in vitro. Following haemocyte treatment with LPS and with LPS from rough mutant R5 (LPS Rc) from Salmonella minnesota, flow cytometric analysis revealed a conspicuous and reproducible decrease in cell size as compared to control haemocytes. These LPS molecules also caused a reduction in haemocyte viability as assessed by flow cytometry with the fluorescent dyes calcein-AM and ethidium homodimer. The onset of cell size reduction was gradual and occurred prior to cell death. Haemocytes treated with LPS from S. minnesota without the Lipid A moiety (detoxified LPS) decreased in size without a reduction of viability. The action of LPS on crayfish haemocytes appeared to be related to the activation of the prophenoloxidase system because phenoloxidase (PO)-specific activity in the supernatants from control and detoxified LPS-treated cells was significantly lower than that from LPS and LPS-Rc treated cells (P < 0.05). Furthermore, addition of trypsin inhibitor to the LPS treatments caused noticeable delays in cell size and viability changes. These patterns of cellular activation by LPS formulations indicated that crayfish haemocytes react differently to the polysaccharide and lipid A moieties of LPS, where lipid A is cytotoxic and the polysaccharide portion is stimulatory. These effects concur with the general pattern of mammalian cell activation by LPS, thereby indicting commone innate immune recognition mechanisms to bacterial antigens between cells from mammals and invertebrates. These definitive molecular approaches used to verify and identify mechanisms of invertbrate haemocyte responses to LPS could be applied with other glycoconjugates, soluble mediators, or xenobiotic compounds.

  7. A trematode parasite alters growth, feeding behavior, and demographic success of invasive rusty crayfish (Orconectes rusticus).

    PubMed

    Sargent, Lindsey W; Baldridge, Ashley K; Vega-Ross, Maraliz; Towle, Kevin M; Lodge, David M

    2014-07-01

    Nonindigenous species can cause major changes to community interactions and ecosystem processes. The strong impacts of these species are often attributed to their high demographic success. While the importance of enemy release in facilitating invasions has often been emphasized, few studies have addressed the role of parasites in the invasive range in controlling demographic success of potential invaders. Here we examine whether a trematode parasite (Microphallus spp.) can contribute to previously documented alternate states in the abundance of invasive rusty crayfish (Orconectes rusticus) in north temperate lakes in Wisconsin, USA. Microphallus infect O. rusticus after emerging from their first intermediate host, a hydrobiid snail. As previously documented, O. rusticus reduce densities of hydrobiid snails through direct predation and destruction of macrophyte habitat. Therefore, if Microphallus substantially reduce O. rusticus fitness, these parasites may reinforce a state of low crayfish abundance, and, at the other extreme, abundant crayfish may repress these parasites, reinforcing a state of high crayfish abundance. From samples collected from 109 sites in 16 lakes, we discovered (1) a positive relationship between crayfish infection intensity and hydrobiid snail abundance, (2) a negative relationship between parasite prevalence and crayfish abundance, and (3) a negative relationship between parasite prevalence and crayfish population growth. With experiments, we found that infection with Microphallus reduced foraging behavior and growth in O. rusticus, which may be the mechanisms responsible for the population reductions we observed. Overall results are consistent with the hypothesis that Microphallus contributes to alternate states in the abundance and impacts of O. rusticus.

  8. Purification, physicochemical and immunological characterization of arginine kinase, an allergen of crayfish (Procambarus clarkii).

    PubMed

    Chen, Heng-Li; Mao, Hai-Yan; Cao, Min-Jie; Cai, Qiu-Feng; Su, Wen-Jin; Zhang, Yong-Xia; Liu, Guang-Ming

    2013-12-01

    Arginine kinase (AK) has attracted considerable attention because it has been identified as a shellfish allergen. However, little information is available about AK in crayfish (Procambarus clarkii). In this study, crayfish AK was purified and cloned. Its physicochemical properties, processing stability, and immunological characteristics were analyzed. Crayfish AK was purified by column chromatography, which revealed a single band with molecular mass of 40 kDa; this result was further confirmed by mass spectrometry. The full-length gene sequence of crayfish AK was 1462 bp and encoded a protein of 357 amino acid residues. The results of this study revealed that crayfish AK is a glycoprotein with an isoelectric point of approximately 6.5. Thermal stability assays revealed that crayfish AK easily forms aggregates at temperatures >44°C and was stable at pH 4.0-8.0. SDS-PAGE and dot blotting were used to assess processing stability of purified AK. The results revealed that the IgE-binding activity of crayfish AK is reduced after boiling.

  9. Intermittent Streams and Habitats Function as Refugia for Fish and Crayfish

    NASA Astrophysics Data System (ADS)

    Magoulick, D. D.; Bare, C. M.; Dekar, M. P.; Hodges, S. W.; Flinders, C. A.; Dick, A.

    2005-05-01

    Drought and summer drying can be important disturbance events in many small streams leading to intermittent or isolated habitats. We examined the influence of stream permanence on fish and crayfish population and community dynamics in multiple streams over several years. We found total crayfish densities and densities of some crayfish species were significantly greater in intermittent than in permanent streams, whereas crayfish species richness did not differ significantly between the two stream types. There was a significant relationship between crayfish relative abundance and abiotic environmental variables for permanent, but not intermittent streams. Fish densities were high in intermittent streams, especially for small species-size classes. Fish moved at large spatial and temporal scales to use intermittent streams, especially for spawning, and fish moved at smaller spatial and temporal scales to avoid drying habitats, especially riffles. During drying events fish survival was greater in pools than in riffles, and pools were more likely to remain permanent habitats. Intermittent streams and permanent pools within dry portions of stream appear to function as refugia for some species and size classes of fish and crayfish. Understanding this relationship will allow natural resource managers to implement effective conservation strategies for fish and crayfish in intermittent streams.

  10. Invasive crayfish as vectors of mercury in freshwater food webs of the Pacific Northwest

    USGS Publications Warehouse

    Johnson, Branden L.; Willacker, James J.; Eagles-Smith, Collin A.; Pearl, Christopher A.; Adams, Michael J.

    2014-01-01

    Invasive species are important drivers of environmental change in aquatic ecosystems and can alter habitat characteristics, community composition, and ecosystem energetics. Such changes have important implications for many ecosystem processes, including the bioaccumulation and biomagnification of contaminants through food webs. Mercury concentrations were measured in 2 nonnative and 1 native crayfish species from western Oregon (USA). Nonnative red swamp crayfish had mercury concentrations similar to those in native signal crayfish (0.29 ± 0.05 µg/g dry wt and 0.36 ± 0.06 µg/g dry wt, respectively), whereas the nonnative ringed crayfish had lower mercury concentrations (0.10 ± 0.02 µg/g dry wt) than either of the other species. The mean energy content of muscle was similar between the native signal crayfish and nonnative ringed crayfish but was significantly higher in the nonnative red swamp crayfish. Across species, mercury concentrations were negatively correlated with energy density. Such energetic differences could exacerbate changes in mercury transfer through trophic pathways of food webs, especially via alterations to the growth dynamics of consumers. Thus, it is important to consider the role of energy content in determining effective mercury exposure even when mercury concentrations on a per-unit mass basis do not differ between species.

  11. Batrachochytrium dendrobatidis in natural and farmed Louisiana crayfish populations: prevalence and implications.

    PubMed

    Brannelly, Laura A; McMahon, Taegan A; Hinton, Mitchell; Lenger, Daniel; Richards-Zawacki, Corinne L

    2015-01-15

    The pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd) has been linked to global declines and extinctions of amphibians, making it one of the most devastating wildlife pathogens known. Understanding the factors that affect disease dynamics in this system is critical for mitigating infection and protecting threatened species. Crayfish are hosts of this pathogen and can transmit Bd to amphibians. Because they co-occur with susceptible amphibian communities, crayfish may be important alternative hosts for Bd. Understanding the prevalence and seasonal dynamics of crayfish infections is of agricultural and ecological interest in areas where crayfish are farmed and traded for human consumption. We conducted a survey of Bd in farmed and natural crayfish (Procambarus spp.) populations in Louisiana, USA. We found that Bd prevalence and infection intensity was low in both farmed and native populations and that prevalence varied seasonally in wild Louisiana crayfish. This seasonal pattern mirrors that seen in local amphibians. As crayfish are an important globally traded freshwater taxon, even with low prevalence, they could be an important vector in the spread of Bd.

  12. Batrachochytrium dendrobatidis in natural and farmed Louisiana crayfish populations: prevalence and implications.

    PubMed

    Brannelly, Laura A; McMahon, Taegan A; Hinton, Mitchell; Lenger, Daniel; Richards-Zawacki, Corinne L

    2015-01-15

    The pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd) has been linked to global declines and extinctions of amphibians, making it one of the most devastating wildlife pathogens known. Understanding the factors that affect disease dynamics in this system is critical for mitigating infection and protecting threatened species. Crayfish are hosts of this pathogen and can transmit Bd to amphibians. Because they co-occur with susceptible amphibian communities, crayfish may be important alternative hosts for Bd. Understanding the prevalence and seasonal dynamics of crayfish infections is of agricultural and ecological interest in areas where crayfish are farmed and traded for human consumption. We conducted a survey of Bd in farmed and natural crayfish (Procambarus spp.) populations in Louisiana, USA. We found that Bd prevalence and infection intensity was low in both farmed and native populations and that prevalence varied seasonally in wild Louisiana crayfish. This seasonal pattern mirrors that seen in local amphibians. As crayfish are an important globally traded freshwater taxon, even with low prevalence, they could be an important vector in the spread of Bd. PMID:25590773

  13. Competition for food between crayfish (Orconectes virilis) and the slimy sculpin (Cottus cognatus)

    USGS Publications Warehouse

    Miller, John E.; Savino, Jacqueline F.; Neely, Robert K.

    1992-01-01

    Interspecific competition for a food resource (fish eggs) was examined in a laboratory setting between two common benthic organisms of the Great Lakes, the slimy sculpin (Cottus cognatus) and crayfish (Orconectes virilis). In monospecific tests, the median egg predation in aquarium microcosms ranged from 2.5 eggs/d for the sculpin to 3.0 eggs/d for the crayfish. In mixed-species tests, sculpin feeding rates were no different than in the monospecific tests. Feeding rates for crayfish, however, were significantly reduced by the presence of sculpin. In mixed-species treatments in which small refuges were included in the aquaria, crayfish predation of eggs was 50% less than in the monospecific tests, i.e., 1.5 eggs/d, and, crayfish went on 93% fewer excursions outside refuges, spent 94% less time outside refuges, and engaged in 83% fewer feeding bouts than sculpin (P≤ 0.05 for all comparisons). When no refuges were provided, crayfish ceased feeding (0 eggs/d). These results suggest the potential for an asymmetrical competitive interaction in a natural setting in which crayfish may be forced into a suboptimal diet by such an interaction with the slimy sculpin.

  14. Juvenile Justice & Youth Violence.

    ERIC Educational Resources Information Center

    Howell, James C.

    Youth violence and the juvenile justice system in the United States are explored. Part 1 takes stock of the situation. The first chapter discusses the origins and evaluation of the juvenile justice system, and the second considers the contributions of the Federal Juvenile Justice and Delinquency Prevention Act to the existing juvenile justice…

  15. Investigation of chloramine-T impact on crayfish Astacus leptodactylus (Esch., 1823) cardiac activity.

    PubMed

    Kuklina, Iryna; Sladkova, Svetlana; Kouba, Antonín; Kholodkevich, Sergey; Kozák, Pavel

    2014-09-01

    The crayfish play an essential role in the biomonitoring and may reflect ambient water quality through the biochemical, behavioural and physiological reactions. To assess whether narrow-clawed crayfish Astacus leptodactylus can respond by heart rate changes to presence in water of such biocide as chloramine-T, adult males were exposed to its low (2 and 5 mg L(-1)), moderate (10 mg L(-1), commonly used in industry and aquaculture) and exceeded (20 and 50 mg L(-1)) concentrations. In addition, a physical stress test evaluated energy expenditure following the chemical trials. Three key reactions (cardiac initial, first-hour and daily prolonged exposure) were discussed with particular focus on crayfish initial reaction as the most meaningful in on-line water quality biomonitoring. After short-term exposure to both chloramine-T concentrations, crayfish were found to respond rapidly, within 2-5 min. According to heart rate changes, the 1-h exposure did not adversely affect crayfish at either concentration, as well as during daily exposure to 10 mg L(-1). As assessed by the heart rate, the 24-h exposure to 50 mg L(-1) of chloramine-T was toxic for crayfish and led to substantial loss of energy that became apparent during subsequently conducted physical stress. The results supported a hypothesis that crayfish vital functions are connected with environment they inhabit closely enough to serve as biological monitors. Crayfish were tolerant to short-term chloramine-T exposure, while rapid crayfish reaction to an increased chemical level indicated their high sensitivity, an essential attribute of real-time environmental assessment.

  16. Crayfish Use of Trash Versus Natural Cover in Incised, Sand-Bed Streams

    NASA Astrophysics Data System (ADS)

    Adams, Susan B.

    2014-02-01

    Historic land use changes and subsequent river channelization created deeply incised, unstable stream channels largely devoid of natural cover throughout the Yazoo River basin, Mississippi, USA. Large trash (e.g., televisions, toilets, car parts) dumped in streams provided shelter for some aquatic fauna. To determine whether trash served as a surrogate for natural cover, I examined crayfish use of both cover types. I sampled crayfishes by kick-seining 2 × 1-m plots in three cover classes: trash, natural cover, and no cover. I captured 415 crayfishes from 136 of the 294 plots. Most crayfishes were in natural cover (253), followed by trash (154), and no-cover (8) plots. Trash use varied by crayfish genus and size. Frequencies of all size classes of Procambarus and of the smallest Cambarus were higher in natural cover than trash. Many of the smallest individuals were found in live root mats. As Cambarus and Orconectes grew, they shifted more toward trash, and the largest Orconectes size class was significantly more abundant than expected in trash. Trash served as "artificial reefs," providing cover for crayfishes and other fauna, but functioned differently than the remaining natural cover. The results confirmed that stream substrate did not provide adequate instream cover for crayfishes in the study area and suggested that high-quality natural cover for large crayfishes was in short supply, at least for some species. Land management that provides for abundant, ongoing input and retention of complex cover, such as trees and live roots, to stream channels should be beneficial for crayfish assemblages.

  17. Crayfish use of trash versus natural cover in incised, sand-bed streams.

    PubMed

    Adams, Susan B

    2014-02-01

    Historic land use changes and subsequent river channelization created deeply incised, unstable stream channels largely devoid of natural cover throughout the Yazoo River basin, Mississippi, USA. Large trash (e.g., televisions, toilets, car parts) dumped in streams provided shelter for some aquatic fauna. To determine whether trash served as a surrogate for natural cover, I examined crayfish use of both cover types. I sampled crayfishes by kick-seining 2 × 1-m plots in three cover classes: trash, natural cover, and no cover. I captured 415 crayfishes from 136 of the 294 plots. Most crayfishes were in natural cover (253), followed by trash (154), and no-cover (8) plots. Trash use varied by crayfish genus and size. Frequencies of all size classes of Procambarus and of the smallest Cambarus were higher in natural cover than trash. Many of the smallest individuals were found in live root mats. As Cambarus and Orconectes grew, they shifted more toward trash, and the largest Orconectes size class was significantly more abundant than expected in trash. Trash served as "artificial reefs," providing cover for crayfishes and other fauna, but functioned differently than the remaining natural cover. The results confirmed that stream substrate did not provide adequate instream cover for crayfishes in the study area and suggested that high-quality natural cover for large crayfishes was in short supply, at least for some species. Land management that provides for abundant, ongoing input and retention of complex cover, such as trees and live roots, to stream channels should be beneficial for crayfish assemblages.

  18. Fatty acid, cholesterol and fat-soluble vitamin composition of wild and captive freshwater crayfish (Astacus leptodactylus).

    PubMed

    Harlioglu, A Gül; Aydin, S; Yilmaz, O

    2012-02-01

    The proximate analysis (dry matter, protein, fat and ash), cholesterol, fatty acid and fat-soluble vitamin compositions of the tail muscle of wild caught and captive crayfish (Astacus leptodactylus) were investigated. Captive crayfish contained higher moisture and fat content than wild crayfish. In contrast, wild crayfish contained a higher level of crude protein, ash and n-3 polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) than captive crayfish. Arachidonic acid (C20:4 n-6) was the major n-6 PUFA in wild A. leptodactylus, and linoleic acid (C18:2 n-6) was the major n-6 PUFA in captive A. leptodactylus. The percentages of total saturated fatty acids (SFA), PUFA, and n-3/n-6 ratio were higher in wild crayfish and total monounsaturated fatty acids (MUFA) were lower. Although differences existed between wild and captive crayfish in vitamins A (p < 0.001), δ-Tocopherol (p < 0.001), α-Tocopherol acetate (p < 0.05), no differences were found in vitamins D(2), D(3), α- Tocopherol and K (p > 0.05). The differences may be originated from the diet provided to captive crayfish. Since wild A. leptodactylus contained higher n-3/n-6 ratio than captive A. leptodactylus, crayfish farms can potentially produce a better quality of crayfish meat by increasing the PUFA n-3 (especially DHA and EPA) in the diets of A. leptodactylus.

  19. Trophic overlap between native and invasive stream crayfish

    USGS Publications Warehouse

    Magoulick, Daniel D.; Piercey, Glenn L.

    2016-01-01

    We examined trophic dynamics of a stream food web where invasive Orconectes neglectusappear to be displacing native O. eupunctus in the Spring River drainage of the Ozark Highlands, Missouri and Arkansas, USA. We collected crayfish species and possible food sources seasonally from a site of sympatry on the South Fork Spring River. We determined diet overlap and potential for competition between O. eupunctus and O. neglectus, and investigated seasonal variation using carbon and nitrogen stable isotope analyses and gut content analyses. Gut content analysis showed both species of crayfish consumed mainly detritus during summer and spring, with other prey categories varying by species and season. Stable isotope analysis showed that O. eupunctus and O. neglectus relied on invertebrates as a major energy and nutrient source throughout summer, autumn, and spring, and the two species showed differences in their stable isotope signatures during spring and summer, but not autumn. Given the trophic overlap between O. eupunctus and O. neglectus, there is a potential for the two species to compete for food and to be ecologically redundant. Ecological redundancy can lead to reduced effects on ecosystem function post-invasion, and therefore examining ecological redundancy of potential invaders should be a conservation priority.

  20. The eyestalk transcriptome of red swamp crayfish Procambarus clarkii.

    PubMed

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

    2015-02-15

    The red swamp crayfish (Procambarus clarkii, Girard 1852) is among the most economically important freshwater crustacean species, and it is also considered one of the most aggressive invasive species worldwide. Despite its commercial importance and being one of the most studied crayfish species, its genomic and transcriptomic layout has only been partially studied. Illumina RNA-sequencing was applied to characterize the eyestalk transcriptome and identify its most characterizing genes. A collection of 83,170,732 reads from eyestalks was obtained using Illumina paired-end sequencing technology. A de novo assembly was performed with the Trinity assembly software generating 119,255 contigs (average length of 1,007 bp) and identifying the first sequenced transcriptome in this species. The eyestalk is a major site for the production of neurohormones and controls a variety of physiological functions such as osmotic regulation, molting, epidermal color patterns and reproduction. Hence, its transcriptomic characterization is interesting and potentially instrumental to the elucidation of genes which have not been comprehensively described yet. Moreover, the availability of such a large amount of information supported the characterization of molecular families which have never been described before. The P. clarkii eyestalk transcriptome reported here provides a resource for improving the knowledge of the still incompletely defined neuroendocrinology of this species and represents an important source of data for all the interested carcinologists.

  1. The parthenogenetic Marmorkrebs (marbled crayfish) produces genetically uniform offspring

    NASA Astrophysics Data System (ADS)

    Martin, Peer; Kohlmann, Klaus; Scholtz, Gerhard

    2007-10-01

    Genetically identical animals are very much in demand as laboratory objects because they allow conclusions about environmental and epigenetic effects on development, structures, and behavior. Furthermore, questions about the relative fitness of various genotypes can be addressed. However, genetically identical animals are relatively rare, in particular, organisms that combine a high reproduction rate and a complex organization. Based on its exclusively parthenogenetic reproduction mode, it has been suggested that the Marmorkrebs (Crustacea, Decapoda, Astacida), a recently discovered crayfish, is an excellent candidate for research addressing the aforementioned questions. However, until now, a study using molecular markers that clearly proves the genetic uniformity of the offspring has been lacking. Here, with this first molecular study, we show that this crayfish indeed produces genetically uniform clones. We tested this with 19 related individuals of various generations of a Marmorkrebs population by means of six different microsatellite markers. We found that all examined specimens were identical in their allelic composition. Furthermore, half of the analyzed loci were heterozygous. These results and the absence of meioses in previous histological studies of the ovaries lead us to conclude the Marmorkrebs propagates apomictically. Thus, a genetically uniform organism with complex morphology, development, and behavior is now available for various laboratory studies.

  2. Heavy metal speciation and uptake in crayfish and tadpoles

    SciTech Connect

    Bundy, K.J.; Berzins, D.; Millet, L.

    1996-12-31

    Developing valid pollution recording methods is central to assessing environmental damage and remediation. This often is difficult, however, because of speciation and multiphase distribution of contaminants. Polarography, an electroanalytical technique capable of detection and quantification of trace levels of elements and ionic complexes, is a promising method for analyzing environmental samples. Here, polarography has been used to determine lead concentration in water, sediment, bullfrogs, tadpoles, and adsorbed onto kaolin. It has also been used to measure hexavalent chromium concentration in crayfish. This research involves field studies and two laboratory experiments. Studies of a Louisiana swamp have shown lead`s affinity for sediment and water particulate phases, rather than being ionically dissolved in the aqueous phase. In swamp bullfrogs, lead was found in greater concentrations in bone compared to muscle. In the first laboratory experiment, lead uptake originating from water and sediment increased in tadpoles as exposure time and concentration increased. Also, this animal`s development was hindered at higher concentrations. The second laboratory experiment exposed crayfish to aqueous hexavalent chromium. Total chromium uptake increased with exposure time and concentration. The chromium tissue abundance was hepatopancreas > gills > muscle. A substantial portion of tissue hexavalent chromium converted to the less toxic trivalent form.

  3. The distribution of polarization sensitivity in the crayfish retinula.

    PubMed

    Glantz, Raymon M

    2007-08-01

    In many arthropod eyes the ommatidia contain two classes of retinular cells with orthogonally oriented microvilli. These receptors provide the basis for two-channel polarization vision. In several contexts such as navigation or the detection of polarization contrast, two channels may be insufficient. While solutions to this problem are known (e.g. in insects and stomatopod crustaceans) none have been found in the majority of decapods. To examine this issue further, the polarization sensitivity and the E-vector angle eliciting a maximum response (theta (max)) were measured at over 300 loci on the crayfish retinula. The polarization response ratio (which is proportional to polarization sensitivity) was similar at all locations on the retinula. Around the central pole of the eye, theta (max) was distributed about the vertical and horizontal axes. Along the dorsal rim, the distribution of theta (max) exhibits modes at 0 degrees , 45 degrees and 90 degrees and a small mode at 135 degrees relative to the dorso-ventral axis of the eyestalk (0 degrees ). Smaller numbers of cells (20 to 25%) with theta (max )near the diagonal were also found in anterior and posterior retinula areas. Thus crayfish visual interneurons, which integrate signals from multiple ommatidia may have access to a multi-channel polarization analyzer. PMID:17598114

  4. Influence of elevated temperature and acid mine drainage on mortality of the crayfish Cambarus bartonii

    USGS Publications Warehouse

    Hartman, K.J.; Hom, C.D.; Mazik, P.M.

    2010-01-01

    Effects of elevated temperature and acid mine drainage (AMD) on crayfish mortality were investigated in the Stony River, Grant County, West Virginia. During summers 2003 and 2004, four-week in situ bioassays were performed along a thermal and AMD gradient with the native crayfish Cambarus bartonii. Crayfish mortality was analyzed in conjunction with temperature and AMD related variables (pH, specific conductivity). Mortality was significantly higher (48-88%) at sites with high temperatures during 2003 (max = 33.0??C), but no significant differences were observed in 2004 (max = 32.0??C). Temperatures were higher in 2003 than 2004 due to increased discharge from a cooling reservoir flowing into the river. Additionally, duration of high temperature was approximately four days in 2003 as compared with only one day in 2004. No significant relationship between acid mine drainage variables and crayfish mortality was apparent.

  5. Ecological effects of lead mining on Ozark streams: In-situ toxicity to woodland crayfish (Orconectes hylas)

    USGS Publications Warehouse

    Allert, A.L.; Fairchild, J.F.; DiStefano, R.J.; Schmitt, C.J.; Brumbaugh, W.G.; Besser, J.M.

    2009-01-01

    The Viburnum Trend mining district in southeast Missouri, USA is one of the largest producers of lead-zinc ore in the world. Previous stream surveys found evidence of increased metal exposure and reduced population densities of crayfish immediately downstream of mining sites. We conducted an in-situ 28-d exposure to assess toxicity of mining-derived metals to the woodland crayfish (Orconectes hylas). Crayfish survival and biomass were significantly lower at mining sites than at reference and downstream sites. Metal concentrations in water, detritus, macroinvertebrates, fish, and crayfish were significantly higher at mining sites, and were negatively correlated with caged crayfish survival. These results support previous field and laboratory studies that showed mining-derived metals negatively affect O. hylas populations in streams draining the Viburnum Trend, and that in-situ toxicity testing was a valuable tool for assessing the impacts of mining on crayfish populations.

  6. Are Chinese consumers at risk due to exposure to metals in crayfish? A bioaccessibility-adjusted probabilistic risk assessment.

    PubMed

    Peng, Qian; Nunes, Luís M; Greenfield, Ben K; Dang, Fei; Zhong, Huan

    2016-03-01

    Freshwater crayfish, the world's third largest crustacean species, has been reported to accumulate high levels of metals, while the current knowledge of potential risk associated with crayfish consumption lags behind that of finfish. We provide the first estimate of human health risk associated with crayfish (Procambarus clarkii) consumption in China, the world's largest producer and consumer of crayfish. We performed Monte Carlo Simulation on a standard risk model parameterized with local data on metal concentrations, bioaccessibility (φ), crayfish consumption rate, and consumer body mass. Bioaccessibility of metals in crayfish was found to be variable (68-95%) and metal-specific, suggesting a potential influence of metal bioaccessibility on effective metal intake. However, sensitivity analysis suggested risk of metals via crayfish consumption was predominantly explained by consumption rate (explaining >92% of total risk estimate variability), rather than metals concentration, bioaccessibility, or body mass. Mean metal concentrations (As, Cd, Cu, Ni, Pb, Se and Zn) in surveyed crayfish samples from 12 provinces in China conformed to national safety standards. However, risk calculation of φ-modified hazard quotient (HQ) and hazard index (HI) suggested that crayfish metals may pose a health risk for very high rate consumers, with a HI of over 24 for the highest rate consumers. Additionally, the φ-modified increased lifetime risk (ILTR) for carcinogenic effects due to the presence of As was above the acceptable level (10(-5)) for both the median (ILTR=2.5×10(-5)) and 90th percentile (ILTR=1.8×10(-4)), highlighting the relatively high risk of As in crayfish. Our results suggest a need to consider crayfish when assessing human dietary exposure to metals and associated health risks, especially for high crayfish-consuming populations, such as in China, USA and Sweden.

  7. Are Chinese consumers at risk due to exposure to metals in crayfish? A bioaccessibility-adjusted probabilistic risk assessment.

    PubMed

    Peng, Qian; Nunes, Luís M; Greenfield, Ben K; Dang, Fei; Zhong, Huan

    2016-03-01

    Freshwater crayfish, the world's third largest crustacean species, has been reported to accumulate high levels of metals, while the current knowledge of potential risk associated with crayfish consumption lags behind that of finfish. We provide the first estimate of human health risk associated with crayfish (Procambarus clarkii) consumption in China, the world's largest producer and consumer of crayfish. We performed Monte Carlo Simulation on a standard risk model parameterized with local data on metal concentrations, bioaccessibility (φ), crayfish consumption rate, and consumer body mass. Bioaccessibility of metals in crayfish was found to be variable (68-95%) and metal-specific, suggesting a potential influence of metal bioaccessibility on effective metal intake. However, sensitivity analysis suggested risk of metals via crayfish consumption was predominantly explained by consumption rate (explaining >92% of total risk estimate variability), rather than metals concentration, bioaccessibility, or body mass. Mean metal concentrations (As, Cd, Cu, Ni, Pb, Se and Zn) in surveyed crayfish samples from 12 provinces in China conformed to national safety standards. However, risk calculation of φ-modified hazard quotient (HQ) and hazard index (HI) suggested that crayfish metals may pose a health risk for very high rate consumers, with a HI of over 24 for the highest rate consumers. Additionally, the φ-modified increased lifetime risk (ILTR) for carcinogenic effects due to the presence of As was above the acceptable level (10(-5)) for both the median (ILTR=2.5×10(-5)) and 90th percentile (ILTR=1.8×10(-4)), highlighting the relatively high risk of As in crayfish. Our results suggest a need to consider crayfish when assessing human dietary exposure to metals and associated health risks, especially for high crayfish-consuming populations, such as in China, USA and Sweden. PMID:26773397

  8. Hardy exotics species in temperate zone: can "warm water" crayfish invaders establish regardless of low temperatures?

    PubMed

    Veselý, Lukáš; Buřič, Miloš; Kouba, Antonín

    2015-01-01

    The spreading of new crayfish species poses a serious risk for freshwater ecosystems; because they are omnivores they influence more than one level in the trophic chain and they represent a significant part of the benthic biomass. Both the environmental change through global warming and the expansion of the pet trade increase the possibilities of their spreading. We investigated the potential of four "warm water" highly invasive crayfish species to overwinter in the temperate zone, so as to predict whether these species pose a risk for European freshwaters. We used 15 specimens of each of the following species: the red swamp crayfish (Procambarus clarkii), the marbled crayfish (Procambarus fallax f. virginalis), the yabby (Cherax destructor), and the redclaw (Cherax quadricarinatus). Specimens were acclimatized and kept for 6.5 months at temperatures simulating the winter temperature regime of European temperate zone lentic ecosystems. We conclude that the red swamp crayfish, marbled crayfish and yabby have the ability to withstand low winter temperatures relevant for lentic habitats in the European temperate zone, making them a serious invasive threat to freshwater ecosystems. PMID:26572317

  9. Distribution, fate and histopathological effects of ethion insecticide on selected organs of the crayfish, Procambarus clarkii.

    PubMed

    Desouky, Mahmoud M A; Abdel-Gawad, Hassan; Hegazi, Bahira

    2013-02-01

    This study aims to investigate the fate and histopathological effects of ethion on selected organs of the crayfish, Procamabrus clarkii. Crayfish were exposed to 1 mg l(-1) (14)C-ethion and the concentrations of ethion and its possible degradation products were measured in water and different organs of the crayfish over both the exposure and recovery periods. Chromatographic analysis revealed that ethion was degraded into ethion monooxon, ethion dioxon, O,O-diethyl phosphorothioate, O-ethyl phosphorothioate and one unknown compound. At the end of exposure period, ethion was accumulated in different organs of the crayfish especially in the hepatopancreas and gills. Following the transfer of crayfish to clean water for seven days, the concentration of insecticide residues were decreased in both the hepatopancreas and gills suggesting that these organs play an important role in elimination of ethion. On the other hand, the exposure of the crayfish to ¼ 96 h-LC(50) (0.36 mg l(-1)) of ethion caused extensive ultrastructural alterations to both hepatopancreas and gill epithelial cells. In the hepatopancreas, the most notable pathological features included vacuolation, degradation and distinct cell lysis. In the gill epithelium, the histopathological alterations included infiltration of hemocytes, cytoplasmic vacuolation and a decrease in the number of basal plasma membrane infoldings.

  10. Incomes, Attitudes, and Occurrences of Invasive Species: An Application to Signal Crayfish in Sweden

    NASA Astrophysics Data System (ADS)

    Gren, Ing-Marie; Campos, Monica; Edsman, Lennart; Bohman, Patrik

    2009-02-01

    This article analyzes and carries out an econometric test of the explanatory power of economic and attitude variables for occurrences of the nonnative signal crayfish in Swedish waters. Signal crayfish are a carrier of plague which threatens the native noble crayfish with extinction. Crayfish are associated with recreational and cultural traditions in Sweden, which may run against environmental preferences for preserving native species. Econometric analysis is carried out using panel data at the municipality level with economic factors and attitudes as explanatory variables, which are derived from a simple dynamic harvesting model. A log-normal model is used for the regression analysis, and the results indicate significant impacts on occurrences of waters with signal crayfish of changes in both economic and attitude variables. Variables reflecting environmental and recreational preferences have unexpected signs, where the former variable has a positive and the latter a negative impact on occurrences of waters with signal crayfish. These effects are, however, counteracted by their respective interaction effect with income.

  11. Olfactory Sampling Recovery Following Sublethal Copper Exposure in the Rusty Crayfish, Orconectes rusticus.

    PubMed

    Lahman, Sara E; Moore, Paul A

    2015-10-01

    Increasing levels of anthropogenic chemicals within an aquatic ecosystem may inhibit animals from extracting information from chemical signals. We investigated whether antennular flicking, a behavioral mechanism involved in chemically-mediated behaviors of the rusty crayfish, Orconectes rusticus, was altered following a sublethal copper exposure (450 µg/L). Crayfish exposed to copper exhibited lower flicking rates than control crayfish and were significantly less successful in their ability to orient to a food odor. Copper was then eliminated from the housing tanks, providing a recovery period. Groups of crayfish were assayed for antennular flicking rates and orientation success three times over the course of the 21 day recovery period. Crayfish demonstrated significant increases in rates of successful localization of odors and antennular flicking during this portion of the experiment. These results indicate that the mechanism by which copper impairs chemoreception in the rusty crayfish is reversible if elevated levels of copper concentrations are eliminated from aquatic ecosystems contaminated by runoff from agricultural or aquacultural chemicals.

  12. The Effects of Biodiesel and Crude Oil on the Foraging Behavior of Rusty Crayfish, Orconectes rusticus.

    PubMed

    Jurcak, Ana M; Gauthier, Steven J; Moore, Paul A

    2015-11-01

    Environmental pollutants, such as crude oil and other petroleum-based fuels, inhibit and limit an organism's ability to perceive a chemical stimulus. Despite the increased use of alternative fuels, such as biodiesel, there have been few studies investigating the impact of these chemicals on the behavior of aquatic organisms. The purpose of this study was to compare the sublethal effects of biodiesel and crude oil exposure on chemically mediated behaviors in a freshwater keystone species. Crayfish (Orconectes rusticus) were tested on their ability to respond appropriately to a positive chemical stimulus within a Y-maze choice paradigm. Behavior was quantified by measuring time spent finding an odor source, duration of time spent at the odor source, percentage of crayfish that found the odor source, and percentage of crayfish that chose the correct arm of the arena. Results indicated negative impacts of both biodiesel and crude oil on the ability of crayfish to locate the food source. However, there were no significant differences between behavioral performances when crayfish were exposed to crude oil compared with biodiesel. Thus, biodiesel and crude oil have equally negative effects on the chemosensory behavior of crayfish. These findings indicate that biodiesel has the potential to have similar negative ecological impacts as other fuel source toxins.

  13. Hardy exotics species in temperate zone: can "warm water" crayfish invaders establish regardless of low temperatures?

    PubMed

    Veselý, Lukáš; Buřič, Miloš; Kouba, Antonín

    2015-11-17

    The spreading of new crayfish species poses a serious risk for freshwater ecosystems; because they are omnivores they influence more than one level in the trophic chain and they represent a significant part of the benthic biomass. Both the environmental change through global warming and the expansion of the pet trade increase the possibilities of their spreading. We investigated the potential of four "warm water" highly invasive crayfish species to overwinter in the temperate zone, so as to predict whether these species pose a risk for European freshwaters. We used 15 specimens of each of the following species: the red swamp crayfish (Procambarus clarkii), the marbled crayfish (Procambarus fallax f. virginalis), the yabby (Cherax destructor), and the redclaw (Cherax quadricarinatus). Specimens were acclimatized and kept for 6.5 months at temperatures simulating the winter temperature regime of European temperate zone lentic ecosystems. We conclude that the red swamp crayfish, marbled crayfish and yabby have the ability to withstand low winter temperatures relevant for lentic habitats in the European temperate zone, making them a serious invasive threat to freshwater ecosystems.

  14. Laboratory experiments to determine if crayfish can communicate chemically in a flow-through system

    SciTech Connect

    Itagaki, H.; Thorp, J.H.

    1981-01-01

    The importance of chemical cues for transmitting information concerning sexual identity, agonistic state, and stress-related condition in the crayfish Procambarus clarkii (Girard) was examined in a flow-through system. Experiments tested the effects of conditioned water from stimulus tanks on the behavior of solitary male or female crayfish. Twenty males and 20 females were subjected to a random sequence of five treatments: unconditioned water (control), conditioned water flowing through tanks containing a solitary male or female, and conditioned water from tanks holding either two males or two females. Durations of the following behaviors were recorded: chelae up, chela(e) in baffle hole, chela waving, climbing, digging, grooming, gross body movement, and meral spread. Results indicated that crayfish chemically detected another animal within 0.25 m without additional visual or tactile stimuli; however, crayfish apparently did not communicate information on sexual identity, agonistic state, or stress condition, nor does this detection necessarily imply discrimination between stimuli from crayfish and other taxa (e.g., fish). Our conclusions are contrasted with the two previous reports on chemical communication in crayfish in which experimental animals were tested in static systems. We suggest that a temporal separation of molting and copulation and a long reproductive receptivity period for females (which would allow abundant intersexual encounters) could account for a lack of selective pressure to evolve long-distance sex pheromones.

  15. Incomes, attitudes, and occurrences of invasive species: an application to signal crayfish in Sweden.

    PubMed

    Gren, Ing-Marie; Campos, Monica; Edsman, Lennart; Bohman, Patrik

    2009-02-01

    This article analyzes and carries out an econometric test of the explanatory power of economic and attitude variables for occurrences of the nonnative signal crayfish in Swedish waters. Signal crayfish are a carrier of plague which threatens the native noble crayfish with extinction. Crayfish are associated with recreational and cultural traditions in Sweden, which may run against environmental preferences for preserving native species. Econometric analysis is carried out using panel data at the municipality level with economic factors and attitudes as explanatory variables, which are derived from a simple dynamic harvesting model. A log-normal model is used for the regression analysis, and the results indicate significant impacts on occurrences of waters with signal crayfish of changes in both economic and attitude variables. Variables reflecting environmental and recreational preferences have unexpected signs, where the former variable has a positive and the latter a negative impact on occurrences of waters with signal crayfish. These effects are, however, counteracted by their respective interaction effect with income.

  16. Predator detection enables juvenile Lymnaea to form long-term memory.

    PubMed

    Orr, M V; Hittel, K; Lukowiak, K

    2010-01-15

    Learning and memory provide the flexibility an organism requires to respond to changing social and ecological conditions. Juvenile Lymnaea have previously been shown to have a diminished capacity to form long-term memory (LTM) following operant conditioning of aerial respiratory behavior. Juvenile Lymnaea, however, can form LTM following classical conditioning of appetitive behaviors. Here, we demonstrate that laboratory-reared juvenile Lymnaea have the ability to detect the presence of a sympatric predator (i.e. crayfish) and respond to the predator by altering their aerial respiratory behavior. In addition to increasing their total breathing time, predator detection confers on juvenile Lymnaea an enhanced capability to form LTM following operant conditioning of aerial respiratory behavior. That is, these juveniles now have the ability to form long-lasting memory. These data support the hypothesis that biologically relevant levels of stress associated with predator detection induce behavioral phenotypic alterations (i.e. enhanced LTM formation) in juveniles, which may increase their fitness. These data also support the notion that learning and memory formation in conjunction with predator detection is a form of inducible defense. PMID:20038665

  17. Predator detection enables juvenile Lymnaea to form long-term memory.

    PubMed

    Orr, M V; Hittel, K; Lukowiak, K

    2010-01-15

    Learning and memory provide the flexibility an organism requires to respond to changing social and ecological conditions. Juvenile Lymnaea have previously been shown to have a diminished capacity to form long-term memory (LTM) following operant conditioning of aerial respiratory behavior. Juvenile Lymnaea, however, can form LTM following classical conditioning of appetitive behaviors. Here, we demonstrate that laboratory-reared juvenile Lymnaea have the ability to detect the presence of a sympatric predator (i.e. crayfish) and respond to the predator by altering their aerial respiratory behavior. In addition to increasing their total breathing time, predator detection confers on juvenile Lymnaea an enhanced capability to form LTM following operant conditioning of aerial respiratory behavior. That is, these juveniles now have the ability to form long-lasting memory. These data support the hypothesis that biologically relevant levels of stress associated with predator detection induce behavioral phenotypic alterations (i.e. enhanced LTM formation) in juveniles, which may increase their fitness. These data also support the notion that learning and memory formation in conjunction with predator detection is a form of inducible defense.

  18. Contrasting patterns of habitat use by prawns and crayfish in a headwater marsh of the St. Johns River, Florida

    USGS Publications Warehouse

    Jordan, Frank; Babbitt, Kimberly J.; McIvor, Carole C.; Miller, Steven J.

    2000-01-01

    We compared seasonal patterns of habitat use by the prawn Palaemonetes paludosus and the crayfish Procambarus alleni in Blue Cypress Marsh Conservation Area, Florida. Prawn densities were similar to those found in other oligotrophic wetlands of southern Florida, whereas crayfish densities were much greater than reported previously for other wetlands in the area. Prawns and crayfish had strikingly different patterns of habitat use. Prawn density and biomass were similar in wet prairies and sloughs, whereas crayfish density and biomass were significantly higher in wet prairies. Within habitats, the abundance of prawns and crayfish generally increased with increasing structural complexity and the abundance of crayfish generally decreased with increasing water depth. Differences in risk of predation, frequency of agonistic encounters, food availability, and other factors likely contributed to observed patterns of habitat use. Because of differences in their ability to burrow and avoid concentration into dry-season refugia, prawns and crayfish responded very differently to seasonal variation in hydrologic conditions. Prawn densities were initially low (following a severe drought) and then increased during much of the study period, whereas crayfish densities were relatively stable throughout the study period. Overall, it appears that prawns are more responsive to antecedent hydrologic conditions and crayfish are more responsive to the availability of suitable habitats such as wet prairies.

  19. Prey availability influences the ontogeny and timing of chemoreception-based prey shifting in the striped crayfish snake, Regina alleni.

    PubMed

    Waters, R Mark; Burghardt, Gordon M

    2013-02-01

    Striped crayfish snakes (Regina alleni) undergo a dietary shift from dragonfly larvae to crayfish during ontogeny. Godley (1980) suggested that this shift is attributable to crayfish availability rather than an initial preference for dragonfly larvae. We experimentally tested this hypothesis by measuring the chemosensory response of newborn snakes to prey odors at 2 ages and also after they were fed on either dragonfly larvae or crayfish. The results show that R. alleni respond equally to dragonfly larvae, hard crayfish, and soft crayfish before feeding experience. We also show that the maintenance of this preference over fish and control stimuli is subsequently determined by the prey type encountered, through an unusual interaction. Snakes fed dragonfly larvae increased their chemosensory response to both dragonfly larvae and crayfish, whereas snakes fed crayfish increased their response only to crayfish. Our study demonstrates that innate chemosensory responses to prey can be modified by prey availability and that they do not necessarily result from maturation alone. Such plasticity has adaptive value to newborn animals that must fend for themselves from birth and respond to changing environmental conditions.

  20. Effects of mining-derived metals on riffle-dwelling crayfish in southwestern Missouri and southeastern Kansas, USA.

    PubMed

    Allert, Ann L; DiStefano, Robert J; Schmitt, Christopher J; Fairchild, James F; Brumbaugh, William G

    2012-11-01

    Riffle-dwelling crayfish populations were sampled at 16 sites in 4 tributaries of the Spring River located within the Tri-State Mining District in southwest Missouri. Crayfish density, physical habitat quality, and water quality were examined at each site to assess the ecological effects of mining-derived metals on crayfish. Metals (lead, zinc, and cadmium) were analyzed in samples of surface water, sediment, detritus, and whole crayfish. Sites were classified a posteriori into reference, mining, and downstream sites primarily based on metal concentrations in the materials analyzed. Three species of crayfish (Orconectes neglectus neglectus, O. macrus, and O. virilis) were collected during the study; however, only O. n. neglectus was collected at all sites. Mean crayfish densities were significantly lower at mining sites than at reference sites. Mean concentrations of metals were significantly correlated among the materials analyzed and were significantly greater at mining and downstream sites than at reference sites. Principal component analyses showed a separation of sites due to an inverse relationship among crayfish density, metals concentrations, and physical habitat quality variables. Sediment probable-effects quotients and surface-water toxic unit scores were significantly correlated; both indicated risk of toxicity to aquatic biota at several sites. Metals concentrations in whole crayfish at several sites exceeded concentrations known to be toxic to carnivorous wildlife. Mining-derived metals have the potential to impair ecosystem function through decreased organic matter processing and nutrient cycling in streams due to decreased crayfish densities.

  1. Effects of mining-derived metals on riffle-dwelling crayfish in southwestern Missouri and southeastern Kansas, USA

    USGS Publications Warehouse

    Allert, Ann L.; DiStefano, Robert J.; Schmitt, Christopher J.; Fairchild, James F.; Brumbaugh, William G.

    2012-01-01

    Riffle-dwelling crayfish populations were sampled at 16 sites in 4 tributaries of the Spring River located within the Tri-State Mining District in southwest Missouri. Crayfish density, physical habitat quality, and water quality were examined at each site to assess the ecological effects of mining-derived metals on crayfish. Metals (lead, zinc, and cadmium) were analyzed in samples of surface water, sediment, detritus, and whole crayfish. Sites were classified a posteriori into reference, mining, and downstream sites primarily based on metal concentrations in the materials analyzed. Three species of crayfish (Orconectes neglectus neglectus, O. macrus, and O. virilis) were collected during the study; however, only O. n. neglectus was collected at all sites. Mean crayfish densities were significantly lower at mining sites than at reference sites. Mean concentrations of metals were significantly correlated among the materials analyzed and were significantly greater at mining and downstream sites than at reference sites. Principal component analyses showed a separation of sites due to an inverse relationship among crayfish density, metals concentrations, and physical habitat quality variables. Sediment probable-effects quotients and surface-water toxic unit scores were significantly correlated; both indicated risk of toxicity to aquatic biota at several sites. Metals concentrations in whole crayfish at several sites exceeded concentrations known to be toxic to carnivorous wildlife. Mining-derived metals have the potential to impair ecosystem function through decreased organic matter processing and nutrient cycling in streams due to decreased crayfish densities.

  2. Effects of mining-derived metals on riffle-dwelling crayfish in southwestern Missouri and southeastern Kansas, USA.

    PubMed

    Allert, Ann L; DiStefano, Robert J; Schmitt, Christopher J; Fairchild, James F; Brumbaugh, William G

    2012-11-01

    Riffle-dwelling crayfish populations were sampled at 16 sites in 4 tributaries of the Spring River located within the Tri-State Mining District in southwest Missouri. Crayfish density, physical habitat quality, and water quality were examined at each site to assess the ecological effects of mining-derived metals on crayfish. Metals (lead, zinc, and cadmium) were analyzed in samples of surface water, sediment, detritus, and whole crayfish. Sites were classified a posteriori into reference, mining, and downstream sites primarily based on metal concentrations in the materials analyzed. Three species of crayfish (Orconectes neglectus neglectus, O. macrus, and O. virilis) were collected during the study; however, only O. n. neglectus was collected at all sites. Mean crayfish densities were significantly lower at mining sites than at reference sites. Mean concentrations of metals were significantly correlated among the materials analyzed and were significantly greater at mining and downstream sites than at reference sites. Principal component analyses showed a separation of sites due to an inverse relationship among crayfish density, metals concentrations, and physical habitat quality variables. Sediment probable-effects quotients and surface-water toxic unit scores were significantly correlated; both indicated risk of toxicity to aquatic biota at several sites. Metals concentrations in whole crayfish at several sites exceeded concentrations known to be toxic to carnivorous wildlife. Mining-derived metals have the potential to impair ecosystem function through decreased organic matter processing and nutrient cycling in streams due to decreased crayfish densities. PMID:22961179

  3. Evaluation of Crayfish Growth and Assimilation on Animal and Detrital Food Sources: Are Stable Isotopes Telling the Whole Story?

    NASA Astrophysics Data System (ADS)

    Warren, L. L.; Wotton, R. S.; Wharton, G.; Fortino, K.; Ulseth, A. J.; Hershey, A. E.

    2005-05-01

    Crayfish are the dominant omnivores of many ecosystems and have strong direct and indirect effects through predation and organic matter processing. Despite this, the importance of detritus for crayfish production is poorly understood. We conducted a laboratory experiment where we fed crayfish an ad. lib. diet of only detritus, only fish tissue, or a mixture the above. The crayfish grew more on a diet which contained meat but growth was highly correlated with the amount of food consumed. The least amount of food was consumed in the detritus treatment, an intermediate amount of food in the meat treatment, and the most food in the mix treatment, suggesting that consumption of detritus by crayfish is related to more than simply the abundance of detritus. Nonetheless, isotopic evidence indicated that the crayfish were not assimilating leaf C and N. Additionally, crayfish in the meat containing treatments never exceeded the del 15N signature of their source by the approximately 3 units expected following fractionation, despite coming to isotopic equilibrium with their source. These findings suggest that crayfish may fractionate C and N uniquely. This difference may have to do with gut microbial activity and may have implications for the interpretation crayfish isotopic signatures.

  4. Juvenile dermatomyositis.

    PubMed

    Quartier, Pierre; Gherardi, Romain K

    2013-01-01

    Juvenile dermatomyositis (JDM) is a systemic, inflammatory, idiopathic disease, mainly affecting the skin and the muscles, starting before the age of 16, with an incidence around one case per 1 million children. Some patients display typical features of JDM without skin involvement, or even without muscle involvement; however, both tissues are affected over time in most cases. Diagnosis criteria were established by Bohan and Peter 35 years ago, based on the presence of typical skin rash and proximal muscle involvement. Other conditions have to be ruled out before making a diagnosis of JDM, such as other connective tissue diseases, polymyositis, infectious/postinfectious myositis, genetic diseases, or metabolic or drug-induced myopathies. Unlike adult-onset dermatomyositis, JDM is exceptionally associated with a malignant disease. JDM may also affect several organs, including the lungs and the digestive tract. In a subset of patients, glucose intolerance, lipodystrophia and/or calcinosis develop. Delay in treatment initiation or inadequate treatment may favor diffuse, debilitating calcinosis. JDM patients have to be referred to reference pediatric centers to properly assess disease activity and disease-related damage (including low bone density in most cases), and to define the best treatment. Long-lasting corticosteroid therapy remains the gold standard, together with physiotherapy. Ongoing clinical trials are assessing the effect of several immunosuppressive and immunomodulatory drugs, which may help to control the disease and possibly demonstrate a corticosteroid-sparing effect. Most patients respond to treatment; relapses are frequent but a complete disease remission is achieved in most cases before adulthood.

  5. Juvenile Delinquency: An Introduction

    ERIC Educational Resources Information Center

    Smith, Carolyn A.

    2008-01-01

    Juvenile Delinquency is a term which is often inaccurately used. This article clarifies definitions, looks at prevalence, and explores the relationship between juvenile delinquency and mental health. Throughout, differences between males and females are explored. (Contains 1 table.)

  6. Biocomplexity and biosimplicity in paddlefish electroreceptors and crayfish mechanoreceptors

    NASA Astrophysics Data System (ADS)

    Moss, Frank

    2001-03-01

    The paddlefish, Polyodon spathula, perceives its world through an array of electroreceptor organs spread over its rostrum [1]. We find long-range anti-correlations in the fluctuations of sequences of time intervals between neural action potentials recorded from spontaneously firing electroreceptor afferents. Long range correlations are an indication of dynamical complexity. In contrast, spontaneous discharges from mechanoreceptor afferents in the crayfish tailfan lack long range correlations altogether. Serving as a control, discharges generated by a simple Hodgkin-Huxley-type model with a noisy membrane potential also lack long-range correlations. We interpret these findings as an indication of the relative complexity of the electroreceptor organ [2] compared with the much more primitive and simple mechanoreceptor. [1] D. Russell, L. Wilkens, and F. Moss, Nature 402, 219 (1999). [2] A. Neiman and D. Russell, Phys. Rev. Lett. in press.

  7. Juvenile Arrests, 2000. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    This bulletin examines the national and state juvenile arrest rate in 2000 using data reported annually by local law enforcement agencies nationwide to the FBI's Uniform Crime Reporting program. Results indicate that the murder rate in 2000 was the lowest since 1965; juvenile arrests for violence in 2000 were the lowest since 1988; few juveniles…

  8. Juvenile Arrests 1996. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    In 1996, law enforcement agencies in the United States made an estimated 2.9 million arrests of persons under the age of 18. According to Federal Bureau of Investigation (FBI) figures, juveniles accounted for 19% of all arrests and 19% of all violent crime in 1996. The substantial growth in juvenile crime that began in the late 1980s peaked in…

  9. Juvenile Arrests, 1999. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    This bulletin presents a summary and analysis of national and state juvenile arrest data for 1999. Data come from the FBI's annual "Crime in the United States" report, which offers the estimated number of crimes reported to law enforcement agencies. The 1999 murder rate was the lowest since 1966. Of the nearly 1,800 juveniles murdered in 1999, 33…

  10. Juvenile Arrests, 1998. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    This report provides a summary and analysis of national and state juvenile arrest data in the United States. In 1998, law enforcement agencies made an estimated 2.6 million arrests of persons under age 18. Federal Bureau of Investigations statistics indicate that juveniles account for 18% of all arrests, and 17% of all violent crime arrests in…

  11. Juvenile Arrests, 2007. Juvenile Justice Bulletin

    ERIC Educational Resources Information Center

    Puzzanchera, Charles

    2009-01-01

    This Bulletin summarizes 2007 juvenile crime and arrest data reported by local law enforcement agencies across the country and cited in the FBI report, "Crime in the United States 2007." The Bulletin describes the extent and nature of juvenile crime that comes to the attention of the justice system. It serves as a baseline for comparison for…

  12. Concepts Shaping Juvenile Justice

    ERIC Educational Resources Information Center

    White, Rob

    2008-01-01

    Rob White's paper explores ways in which community building can be integrated into the practices of juvenile justice work. He provides a model of what can be called "restorative social justice", one that builds upon the juvenile conferencing model by attempting to fuse social justice concerns with progressive juvenile justice practices.

  13. Juveniles in court.

    PubMed

    Soulier, Matthew F; Scott, Charles L

    2010-01-01

    Nineteenth-century American reformers were concerned about the influence of immaturity and development in juvenile offenses. They responded to their delinquent youths through the creation of juvenile courts. This early American juvenile justice system sought to treat children as different from adults and to rehabilitate wayward youths through the state's assumption of a parental role. Although these rehabilitative goals were never fully realized, the field of American child psychiatry was spawned from these efforts on behalf of delinquent youths. Early child psychiatrists began by caring for juvenile offenders. The function of a child psychiatrist with juvenile delinquents expanded beyond strictly rehabilitation, however, as juvenile courts evolved to resemble criminal adult courts-due to landmark Supreme Court decisions and also juvenile legislation between 1966 and 1975. In response to dramatically increased juvenile violence and delinquency rates in the 1980s, juvenile justice became more retributional, and society was forced to confront issues such as capital punishment for juveniles, their transfer to adult courts, and their competency to stand trial. In the modern juvenile court, child psychiatrists are often asked to participate in the consideration of such issues because of their expertise in development. In that context we review the role of psychiatrists in assisting juvenile courts.

  14. Effects of natural flooding and manual trapping on the facilitation of invasive crayfish-native amphibian coexistence in a semi-arid perennial stream

    USGS Publications Warehouse

    Kats, Lee B.; Bucciarelli, Gary; Vandergon, Thomas L.; Honeycutt, Rodney L.; Mattiasen, Evan; Sanders, Arthur; Riley, Seth P.D.; Kerby, Jacob L.; Fisher, Robert N.

    2013-01-01

    Aquatic amphibians are known to be vulnerable to a myriad of invasive predators. Invasive crayfish are thought to have eliminated native populations of amphibians in some streams in the semi-arid Santa Monica Mountains of southern California. Despite their toxic skin secretions that defend them from native predators, newts are vulnerable to crayfish attacks, and crayfish have been observed attacking adult newts, and eating newt egg masses and larvae. For 15 years, we have observed invasive crayfish and native California newts coexisting in one stream in the Santa Monica Mountains. During that period, we monitored the densities of both crayfish and newt egg mass densities and compared these to annual rainfall totals. After three seasons of below average rainfall, we reduced crayfish numbers by manual trapping. Our long-term data indicated that crayfish did not fare well in years when rainfall is above the historic average. This invasive predator did not evolve with high velocity streams, and observations indicated that southern California storm events washed crayfish downstream, killing many of them. Newts exhibit increased reproduction in years when crayfish numbers were reduced. A comparison with a nearby stream that does not contain crayfish indicated that newt reproduction positively responded to increased rainfall, but that fluctuations were much greater in the stream that contains crayfish. We suggest that rainfall patterns help explain invasive crayfish/newt coexistence and that management for future coexistence may benefit from manual trapping.

  15. Juveniles on trial.

    PubMed

    Quinn, Kathleen M

    2002-10-01

    This article describes common forensic evaluations requested of juvenile court mental health evaluators. There has been a legal shift toward criminalization of juvenile court, with a greater emphasis on rights, abandonment of the rehabilitative model, and greater movement of adolescents into the adult criminal court. A resulting shift has been the redefinition of juvenile court forensic evaluations toward the specificity of adult forensic work. The challenge for evaluators is to refine their knowledge of the forensic standards and bring knowledge of development, assessment, and diagnosis in juveniles and interview techniques appropriate to juveniles to improve the evaluation and forensic reports.

  16. Invasive crayfish reduce food limitation of alien American mink and increase their resilience to control.

    PubMed

    Melero, Yolanda; Palazón, Santiago; Lambin, Xavier

    2014-02-01

    Trophic relationships between invasive species in multiply invaded ecosystems may reduce food limitation relative to more pristine ecosystems and increase resilience to control. Here, we consider whether invasive predatory American mink Neovison vison are trophically subsidized by invasive crayfish. We collated data from the literature on density and home range size of mink populations in relation to the prevalence of crayfish in the diet of mink. We then tested the hypothesis that populations of an invasive predator reach higher densities and are more resilient to lethal control when they have access to super-abundant non-native prey, even in the absence of changes in density dependence, hence compensatory capacity. We found a strong positive relationship between the proportion of crayfish in mink diet and mink population density, and a negative relationship between the proportion of crayfish in mink diet and mink home range size, with crayfish contribution to mink diet reflecting their abundance in the ecosystem. We then explored the consequence of elevated mink density by simulating a hypothetical eradication program with a constant harvest in a Ricker model. We found that mink populations were more resilient to harvest in the presence of crayfish. As a result, the simulated number of mink harvested to achieve eradication increased by 500% in the presence of abundant crayfish if carrying capacity increased by 630%. This led to a threefold increase in time to eradication under a constant harvest and an approximately 20-fold increase in the cumulative management cost. Our results add to evidence of inter-specific positive interactions involving invasive species, and our simple model illustrates how this increases management cost. PMID:24065555

  17. Invasive crayfish as vectors of mercury in freshwater food webs of the Pacific Northwest.

    PubMed

    Johnson, Branden L; Willacker, James J; Eagles-Smith, Collin A; Pearl, Christopher A; Adams, Michael J

    2014-11-01

    Invasive species are important drivers of environmental change in aquatic ecosystems and can alter habitat characteristics, community composition, and ecosystem energetics. Such changes have important implications for many ecosystem processes, including the bioaccumulation and biomagnification of contaminants through food webs. Mercury concentrations were measured in 2 nonnative and 1 native crayfish species from western Oregon (USA). Nonnative red swamp crayfish had mercury concentrations similar to those in native signal crayfish (0.29 ± 0.05 µg/g dry wt and 0.36 ± 0.06 µg/g dry wt, respectively), whereas the nonnative ringed crayfish had lower mercury concentrations (0.10 ± 0.02 µg/g dry wt) than either of the other species. The mean energy content of muscle was similar between the native signal crayfish and nonnative ringed crayfish but was significantly higher in the nonnative red swamp crayfish. Across species, mercury concentrations were negatively correlated with energy density. Such energetic differences could exacerbate changes in mercury transfer through trophic pathways of food webs, especially via alterations to the growth dynamics of consumers. Thus, it is important to consider the role of energy content in determining effective mercury exposure even when mercury concentrations on a per-unit mass basis do not differ between species. Environ Toxicol Chem 2014;33:2639-2645. Published 2014 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US Government work and as such, is in the public domain in the United States of America.

  18. Invasive crayfish reduce food limitation of alien American mink and increase their resilience to control.

    PubMed

    Melero, Yolanda; Palazón, Santiago; Lambin, Xavier

    2014-02-01

    Trophic relationships between invasive species in multiply invaded ecosystems may reduce food limitation relative to more pristine ecosystems and increase resilience to control. Here, we consider whether invasive predatory American mink Neovison vison are trophically subsidized by invasive crayfish. We collated data from the literature on density and home range size of mink populations in relation to the prevalence of crayfish in the diet of mink. We then tested the hypothesis that populations of an invasive predator reach higher densities and are more resilient to lethal control when they have access to super-abundant non-native prey, even in the absence of changes in density dependence, hence compensatory capacity. We found a strong positive relationship between the proportion of crayfish in mink diet and mink population density, and a negative relationship between the proportion of crayfish in mink diet and mink home range size, with crayfish contribution to mink diet reflecting their abundance in the ecosystem. We then explored the consequence of elevated mink density by simulating a hypothetical eradication program with a constant harvest in a Ricker model. We found that mink populations were more resilient to harvest in the presence of crayfish. As a result, the simulated number of mink harvested to achieve eradication increased by 500% in the presence of abundant crayfish if carrying capacity increased by 630%. This led to a threefold increase in time to eradication under a constant harvest and an approximately 20-fold increase in the cumulative management cost. Our results add to evidence of inter-specific positive interactions involving invasive species, and our simple model illustrates how this increases management cost.

  19. Consumptive effects of fish reduce wetland crayfish recruitment and drive species turnover.

    PubMed

    Kellogg, Christopher M; Dorn, Nathan J

    2012-04-01

    Predators and dry-disturbances have pronounced effects on invertebrate communities and can deterministically affect compositional turnover between discrete aquatic habitats. We examined the effect of sunfish (Lepomis spp.) predators on two native crayfish, Procambarus alleni and P. fallax, that regionally coexist in an expansive connected wetland in order to test the hypotheses that sunfish predation limits crayfish recruitment (both species) and that it disproportionately affects P. alleni, the species inhabiting temporary wetlands. In replicate vegetated wetlands (18.6 m(2)), we quantified summertime crayfish recruitment and species composition across an experimental gradient of sunfish density. Separately, we quantified effects of sunfish on crayfish growth, conducted a complimentary predation assay in mesocosms, and compared behavior of the two crayfish. Sunfish reduced P. alleni summertime recruitment by >99% over the full sunfish gradient, and most of the effect was caused by low densities of sunfish (0.22-0.43 m(-2)). P. alleni dominated wetlands with few or no sunfish, but the composition shifted towards P. fallax dominance in wetlands with abundant sunfish. P. fallax survived better than P. alleni over 40 h in smaller mesocosms stocked with warmouth. Sunfish reduced P. fallax recruitment 62% in a second wetland experiment, but growth rates of caged crayfish (both species) were unaffected by sunfish presence, suggesting predatory effects were primarily consumptive. Consistent with life histories of relatively fish-sensitive invertebrates, P. alleni engaged in more risky behaviors in the laboratory. Our results indicate that sunfish predators limit recruitment of both species, but disproportionately remove the more active and competitively dominant P. alleni. Spatially and temporally variable dry-disturbances negatively co-varying with sunfish populations allow for regional coexistence of these two crayfish and may release populations of either species from

  20. Overexpression of a C-type lectin enhances bacterial resistance in red swamp crayfish Procambarus clarkii.

    PubMed

    Zhang, Xiao-Wen; Liu, Ying-Ying; Mu, Yi; Ren, Qian; Zhao, Xiao-Fan; Wang, Jin-Xing

    2013-05-01

    C-type lectins play important roles in the innate immune system of crustaceans. In this study, a novel C-type lectin gene, designated as PcLec4, was obtained from the red swamp crayfish (Procambarus clarkii). Quantitative real-time polymerase chain reaction revealed that PcLec4 is mainly expressed in the crayfish hepatopancreas and intestine, and the PcLec4 mRNA expression is upregulated after challenged with the bacteria Vibrio anguillarum. PcLec4 was recombinantly expressed in Escherichia coli and anti-PcLec4 polyclonal antiserum was prepared. Binding experiments revealed that the recombinant PcLec4 binds to various bacteria and polysaccharides on the bacterial surface, which suggests that PcLec4 recognizes bacterial pathogens. Overexpression of PcLec4 in crayfish using the pIeLec4 vector was performed. The results show that the crayfish overexpressing PcLec4 eliminate injected V. anguillarum more quickly than the control, which suggests that PcLec4 elicits further immune response for removing invading bacteria. The results of the survival experiment confirmed the function of PcLec4 in resisting V. anguillarum because PcLec4 overexpression in crayfish significantly increased the crayfish survival rate. These results reveal that PcLec4 has an important role in the antibacterial immunity of crayfish, and in vivo PcLec4 overexpression might be used as a disease control strategy in aquiculture.

  1. Morphine-conditioned cue alters c-Fos protein expression in the brain of crayfish.

    PubMed

    Dziopa, Leah; Imeh-Nathaniel, Adebobola; Baier, Dana; Kiel, Michael; Sameera, Sayeed; Brager, Adam; Beatriz, Vega; Nathaniel, Thomas I

    2011-07-15

    With a highly organized stereotypic behavior and a simplified neuronal system that is characterized by cellular modularity, crayfish (Orconectes rusticus) represents an excellent model that we used in this study to explore how a drug-conditioned-cue alters c-Fos protein expression in the brain of an invertebrate species. The first set of experiments revealed that a single injection of different doses of morphine (3.0 μg/g, 6.0 μg/g and 12.0 μg/g) into the circulatory system of crayfish significantly increased locomotor activity. Repeated injections of morphine increased locomotion at lower doses (3.0 μg/g and 6.0 μg/g), and decreased locomotion at a higher dose of 12.0 μg/g. The second experiment revealed that a repeated or single injection of morphine serves as reward when paired with a distinct visual environment. In the third experiment, we found that the c-Fos profile of morphine treated crayfish in an unconditioned environment did not show a significant increase from the basal level comparable to saline treated crayfish. The brains of crayfish were more active during exposure to the cue-elicited drug conditioned environment than the unconditioned environment. These results indicate that chronic morphine treatment alone is not sufficient to induce changes in the expression of c-Fos; instead, morphine-environment pairing in a specific context contributes to the expression of alterations in c-Fos regulation. The enhancement of c-Fos expression in the brain of crayfish seems to reflect the sensory or anticipatory facets of conditioning that suggests that potential and even unanticipated hypotheses in drug addiction can emerge from studies of addiction in crayfish.

  2. Phenogenetic analysis of crayfishes Astacus astacus population dynamics after introduction into natural lake

    NASA Astrophysics Data System (ADS)

    Sapunov, Valentin; Fedotov, Valery

    2016-04-01

    Phenogenetic indication is check of environment state by detectable characters of population, such as morphological variability, sex relation and sex dimorphism. This characters dynamics was followed within crayfish population during process of adaptation for pond. Crayfishes are stenobionts needing clean water. The pattern of different crayfish species is criteria for pond dynamics. Mathematical model describing occupation of lake by Nobel crayfishes Astacus astacus is describing by two variants. The first is general universal model, the second is model appropriate for lake Berezno from Pskov region (North - West of Russia). This situation may be considered as representative for different lakes taking into account ecological specific of every lake. Crayfishes were introduced into the lake at 1995. At 1998 population was reorganized by switching on genetic program of migration for maximal using of assimilating capacity of lake. During 2000 - 2015 population was stable and its characters were oscillated according to ecological state and automatic genetics processes. Population is monomorphic, the one morphotype is dominant. Sizes within this morpotype are distributed according to Gauss law (making correction for methods of catching). The square deviation increases in first generation and decreases in accordance to population adaptation. The Nobel crayfish is typical macrohydrobiont and may be used as biological indicator of ecological state of water. Such a method of monitoring is cheap and effective and may be used as adding to tradition monitoring manner. Parallel to monitoring of natural crayfish population the program of use of artificial test system for water quality was introduced in water-supply station of St. Petersburg.

  3. Energy sources and ecological role of crayfishes in an Ozark stream: Insights from stable isotopes and gut analysis

    USGS Publications Warehouse

    Whitledge, G.W.; Rabeni, C.F.

    1997-01-01

    Energy sources for the crayfishes Orconectes luteus and O. punctimanus in the Jacks Fork River, Missouri, were quantified using stable isotopes (??13C and ??15N) and gut-content analysis. A dual-isotope mixing model indicated that about two thirds of crayfish production originated from allochthonous carbon sources, and 30-50% of crayfish production was derived from direct consumption of animal matter. Young-of-the-year crayfishes and adult O. luteus were more carnivorous than the larger adult O. punctimanus. Contributions of energy sources determined using the stable isotope mixing model were similar to results of gut-content analysis corrected for differential assimilation of dietary components. Proportions of crayfish production attributed to animal matter by these two methods were four to five times greater than estimates derived from uncorrected gut-content analysis. Unadjusted gut-content analysis overestimated the percentage of crayfish production from feeding directly on detritus. Production-based calculations of crayfish food consumption rates indicated that crayfishes were the dominant consumers of benthic invertebrates, detritus, and algae and may strongly influence lower trophic levels, organic matter processing, and energy flow in this system.

  4. The Effect of the Crayfish Orconectes virilis (Crustacea: Decapoda: Cambaridae) in the Decomposition and Succession of Submerged Small Mammal Carrion

    NASA Astrophysics Data System (ADS)

    de Jong, G. D.; Chadwick, J. W.

    2005-05-01

    The role of the crayfish Orconectes virilis in the decomposition of submerged rat carrion and succession of other benthic macroinvertebrates was experimentally investigated in Slaughterhouse Gulch, a small, urban stream in Littleton, Colorado. Crayfish participation in carrion decomposition significantly altered the decomposition rate of the carrion. Nine carcasses were exposed in anchored minnow traps at three degrees of crayfish access: crayfish always present, crayfish having free access, and crayfish excluded. These three treatments required 23 days, 29 days, and 65 days, respectively, for complete decomposition of the rat carrion (<2% original biomass). Sample variability increased with number of crayfish present, especially as decomposition proceeded. Seven other macroinvertebrate taxa were collected from the carcasses, but their presence or absence could not be correlated with crayfish presence. The leech Haemopis marmoratus was generally the first macroinvertebrate to arrive at the carrion, being present in densities of <5 individuals/carcass early in succession and in larger densities (up to 25 individuals/carcass) after extensive decomposition and exposure of the viscera.

  5. Static Magnetic Field Induces Changes in Behavior and Electrical Activity of the Nervous System of the Crayfish

    NASA Astrophysics Data System (ADS)

    Alvarado-Alvarez, R.; Godina-Nava, J. J.; Serrano, G.; Suaste, E.; Rodríguez-Segura, M. A.; Toledo-Ramos, F.

    2002-08-01

    The influence of static magnetic fields over the behaviour of crayfish was studied. Under this condition, the response tendency of the crayfish was observed either toward north-west or north-east direction according the local magnetic north. This behaviour was concurrent with neural discharges recorded from the cerebral ganglia.

  6. A Successful Crayfish Invader Is Capable of Facultative Parthenogenesis: A Novel Reproductive Mode in Decapod Crustaceans

    PubMed Central

    Buřič, Miloš; Hulák, Martin; Kouba, Antonín

    2011-01-01

    Biological invasions are impacting biota worldwide, and explaining why some taxa tend to become invasive is of major scientific interest. North American crayfish species, particularly of the family Cambaridae, are prominent invaders in freshwaters, defying the “tens rule” which states that only a minority of species introduced to new regions become established, and only a minority of those become invasive and pests. So far, success of cambarid invaders has largely been attributed to rapid maturation, high reproductive output, aggressiveness, and tolerance to pollution. We provide experimental evidence that females of one cambarid species particularly widespread in Europe, the spiny-cheek crayfish Orconectes limosus, are capable of facultative parthenogenesis. Such reproductive mode has never before been recognized in decapods, the most diverse crustacean order. As shown by analysis of seven microsatellite loci, crayfish females kept physically separated from males produced genetically homogeneous offspring identical with maternal individuals; this suggests they reproduced by apomixis, unlike those females which mated with males and had a diverse offspring. Further research is needed to clarify what environmental conditions are necessary for a switch to parthenogenesis in O. limosus, and what role it plays in natural crayfish populations. However, if such reproductive plasticity is present in other cambarid crayfish species, it may contribute to the overwhelming invasive success of this group. PMID:21655282

  7. Toxicological studies of cadmium and zinc on the crayfish Orconectes virilis

    SciTech Connect

    Mirenda, R.J.

    1985-01-01

    The acute toxicities of cadmium and of zinc to the crayfish Oronectes virilis were determined. Adult, intermolt crayfish were exposed to a series of concentrations of either cadmium or zinc for a two week period. Cadmium was found to be a cumulative poison to the crayfish; LC50 values decreased from 6.1 mg Cd/I for 96 hours to 0.7 mg Cd/I for two weeks. An incipient LC50 was also estimated to be 0.0604 mg Cd/I. Zinc was found to have a relatively low toxicity to O. virilis under the present exposure conditions. Whole animal and tissue analyses for cadmium or zinc were performed on the crayfish used in the acute toxicity tests. Whole animals concentrations both for cadmium and for zinc exhibited a linear relationship to exposure concentrations (r = 0.85 and 0.87, respectively). The gills had the highest concentrations (r = 0.85 and 0.87, respectively). The gills had the highest concentrations of cadmium and zinc, and displayed a linear relationship to exposure concentrations (r = 0.82 and 0.87 respectively). The hepatopancreas displayed a plateau in metal concentrations and is probably the main storage site for both metals in the crayfish. The relationship of cadmium concentration to exposure concentration in the antennal glands also showed linearity (r = 0.65), while zinc levels reached a steady state level. All the remaining tissues analyzed exhibited a plateau in metal concentration.

  8. Accumulation of heavy metals in crayfish and fish from selected Czech reservoirs.

    PubMed

    Kuklina, Iryna; Kouba, Antonín; Buřič, Miloš; Horká, Ivona; Duriš, Zdeněk; Kozák, Pavel

    2014-01-01

    To evaluate the accumulation of aluminium, cadmium, chromium, copper, lead, mercury, nickel, and zinc in crayfish and fish organ tissues, specimens from three drinking water reservoirs (Boskovice, Landštejn, and Nová Říše) and one contaminated site (Darkovské moře) in the Czech Republic were examined. Crayfish hepatopancreas was confirmed to be the primary accumulating site for the majority of metals (Cu > Zn > Ni > Cd > Cr), while Hg and Cr were concentrated in abdominal muscle, and Al and Pb were concentrated in gill. Metals found in Nová Říše specimens included Cu > Zn > Ni and those found in Boskovice included Zn > Hg > Cr. Cd concentrations were observed only in Landštejn specimens, while contaminated Darkovské moře specimens showed the highest levels of accumulation (Cu > Al > Zn > Pb). The majority of evaluated metals were found in higher concentrations in crayfish: Cu > Al > Zn > Ni > Cr > Cd > Pb, with Hg being the only metal accumulating higher in fish. Due to accumulation similarities of Al in crayfish and fish gill, differences of Hg in muscle, and features noted for the remaining metals in examined tissues, biomonitoring should incorporate both crayfish and fish to produce more relevant water quality surveys.

  9. Cadmium-binding proteins in midgut gland of freshwater crayfish Procambarus clarkii

    SciTech Connect

    Del Ramo, J.; Pastor, A.; Torreblanca, A.; Medina, J.; Diza-Mayans, J.

    1989-02-01

    Metallothioneins, metal binding proteins, were originally isolated and characterized by Margoshes and Vallee. These proteins have a high affinity for various heavy metals, particularly cadmium and mercury and have extensively been studied in mammals. Metal binding proteins have been observed in a variety of marine invertebrates; however, there is very little information available on metal binding proteins in freshwater invertebrates, and particularly in freshwater crustaceans. Cadmium is an ubiquitous non essential element which possesses high toxicity to aquatic organisms. Cadmium binding proteins observed in invertebrates have similar characteristics to mammalian metallothioneins. In 1978, the American red crayfish appeared in Albufera Lake and the surrounding rice fields (Valencia, Spain). Albufera Lake and the surrounding rice fields waters are subjected to very heavy loads of sewage and toxic industrial residues (including heavy metals) from the many urban and wastewaters in this area. In previous reports the authors studied the toxicity and accumulation of cadmium on Procambarus clarkii of Albufera Lake. This crayfish shows a high resistance to cadmium and a great accumulation rate of this metal in several tissues, including midgut gland. Since Procambarus clarkii shows a high resistance to cadmium, the presence of cadmium binding proteins (Cd-BP) in midgut gland of these crayfish would be expected. This report describes results on the characterization of Cd-BPs obtained from cadmium exposed crayfish Procambarus clarkii, demonstrating their presence in this freshwater crayfish.

  10. Physical habitat and water quality correlates of crayfish distributions in a mined watershed

    USGS Publications Warehouse

    Welsh, Stuart; Loughman, Zachary J.

    2014-01-01

    In mined watersheds, water quality alters aquatic faunas, but few studies have focused on associations between stream habitat and crayfish distributions. We examined associations of water quality and physical habitat quality on presence/absence of six crayfish species in the upper Kanawha River drainage of southern West Virginia, USA, a region with a long history of surface and mountaintop removal mining of coal. Data supported an association of physical habitat quality with the presence of four species (Cambarus carinirostris, Cambarus robustus, Cambarus cf. sciotensis, and Orconectes sanbornii). Cambarus bartonii cavatus and the non-native Orconectes virilis were associated with lower quality physical habitat than that of the other four species. Relative to other species, C. b. cavatus was associated with the lowest conductivity values, whereas O. virilis was associated with the highest conductivity values. Secondary and tertiary burrowers were generally associated with relatively high-quality physical habitat. However, C. b. cavatus, a crayfish known to burrow extensively in headwater streams, was associated with the lowest quality physical habitat. Physical habitat quality was generally supported over stream conductivity as a variable influencing crayfish distributions. Our data demonstrate the importance of stream habitat quality when assessing crayfish assemblages within mined watersheds.

  11. Effects of Current Velocity, Particle Size, and Substrate Heterogeneity on Crayfish (Orconectes propinquus) Activity

    NASA Astrophysics Data System (ADS)

    Clark, J. M.; Kershner, M. W.

    2005-05-01

    The use of flow refugia (e.g., substrate) by lotic invertebrates often increases their likelihood of survival during flood events. Movement to potential refugia becomes risky as velocities increase, and the range of velocities that benthic invertebrates can withstand is variable. In this study, activity time and slip velocities of small [carapace length (CL)=10-20 mm] and large (CL=20-30 mm) Orconectes propinquus were measured in an artificial flume across ranges of current velocity and substrate heterogeneity. Particle sizes included small pebbles (16-32 mm), large pebbles (32-64 mm), and small cobble (64-128 mm). Water velocity was increased by 0.1 m/s increments from 0.1-1.5 m/s at 5-minute intervals or until the crayfish was dislodged from the substrate. As current velocity increased, the probability of slipping increased for all crayfish. Regardless of the degree of substrate heterogeneity, small crayfish held their position at higher velocities than large crayfish and were also less active. Slip rates were generally lower for both sizes as substrate heterogeneity increased. Essentially, the availability and probability of finding refugia increased with increased habitat heterogeneity and allowed crayfish to avoid being swept into the drift.

  12. BAX inhibitor-1 silencing suppresses white spot syndrome virus replication in red swamp crayfish, Procambarus clarkii.

    PubMed

    Du, Zhi-Qiang; Lan, Jiang-Feng; Weng, Yu-Ding; Zhao, Xiao-Fan; Wang, Jin-Xing

    2013-07-01

    BAX inhibitor-1 (BI-1) was originally described as an anti-apoptotic protein in both animal and plant cells. BI-1 overexpression suppresses ER stress-induced apoptosis in animal cells. Inhibition of BI-1 activity could induce the cell death in mammals and plants. However, the function of BI-1 in crustacean immunity was unclear. In this paper, the full-length cDNA of a BI-1 protein in red swamp crayfish, Procambarus clarkii (PcBI-1) was cloned and its expression profiles in normal and infected crayfish were analyzed. The results showed that PcBI-1 was expressed in hemocytes, heart, hepatopancreas, gills, stomach, and intestines of the crayfish and was upregulated after challenged with Vibrio anguillarum and with white spot syndrome virus (WSSV). To determine the function of PcBI-1 in the innate immunity of the crayfish, the RNA interference against PcBI-1 was performed and the results indicated the hemocyte programmed cell death rate was increased significantly and WSSV replication was declined after PcBI-1 knocked down. Altogether, PcBI-1 plays an anti-apoptotic role, wherein high PcBI-1 expression suppresses programmed cell death, which is beneficial for WSSW replication in crayfish.

  13. Accumulation of Heavy Metals in Crayfish and Fish from Selected Czech Reservoirs

    PubMed Central

    Kuklina, Iryna; Kouba, Antonín; Buřič, Miloš; Horká, Ivona; Ďuriš, Zdeněk; Kozák, Pavel

    2014-01-01

    To evaluate the accumulation of aluminium, cadmium, chromium, copper, lead, mercury, nickel, and zinc in crayfish and fish organ tissues, specimens from three drinking water reservoirs (Boskovice, Landštejn, and Nová Říše) and one contaminated site (Darkovské moře) in the Czech Republic were examined. Crayfish hepatopancreas was confirmed to be the primary accumulating site for the majority of metals (Cu > Zn > Ni > Cd > Cr), while Hg and Cr were concentrated in abdominal muscle, and Al and Pb were concentrated in gill. Metals found in Nová Říše specimens included Cu > Zn > Ni and those found in Boskovice included Zn > Hg > Cr. Cd concentrations were observed only in Landštejn specimens, while contaminated Darkovské moře specimens showed the highest levels of accumulation (Cu > Al > Zn > Pb). The majority of evaluated metals were found in higher concentrations in crayfish: Cu > Al > Zn > Ni > Cr > Cd > Pb, with Hg being the only metal accumulating higher in fish. Due to accumulation similarities of Al in crayfish and fish gill, differences of Hg in muscle, and features noted for the remaining metals in examined tissues, biomonitoring should incorporate both crayfish and fish to produce more relevant water quality surveys. PMID:24738051

  14. Mercury in the northern crayfish, Orconectes virilis (Hagen), in New England, USA.

    PubMed

    Pennuto, Chris M; Lane, Oksana P; Evers, David C; Taylor, Robert J; Loukmas, Jeff

    2005-03-01

    Biologists and policy makers continue to seek environmental correlates of mercury bioavailability in aquatic ecosystems. In this study, we assessed the effects of drainage basin, habitat type, size class, and sex on mercury concentrations in the northern crayfish, Orconectes virilis (Hagen). Drainage basin, habitat type, and size class had significant effects on mercury concentration in crayfish tail muscle even though animals from roughly half the sites examined had mean mercury values at or below expected background levels. The low observed mercury values in crayfish tail muscle indicate a low consumptive risk. Contrary to expectations, crayfish from brooks had higher mercury concentrations than animals from other habitat types, possibly as a result of point source contamination or varying diet compositions among habitats. We suggest that crayfish represent a good indicator of mercury bioavailability in aquatic ecosystems and provide a synthesis for lower food webs. Our understanding of mercury dynamics in lower food webs has been hindered by an under appreciation of the complexity in foraging habits of macroinvertebrates. Further studies focusing on benthos with well-understood life histories and foraging behavior are essential to improve our understanding of mercury transfer and bioavailability through aquatic systems.

  15. Circadian and ultradian rhythms in the crayfish caudal photoreceptor.

    PubMed

    Rodríguez-Sosa, Leonardo; Calderón-Rosete, Gabina; Flores, Gonzalo

    2008-09-01

    The study of circadian clocks in crustaceans has led to the hypothesis of a distributed circadian system of pacemakers. In this review, we investigate the role of the crayfish caudal photoreceptor (CPR) as a candidate to form part of this pacemaking circadian system. Two circadian rhythms are documented for CPR electrical activity. These rhythms correspond to the spontaneous and light-induced discharge of action potentials. The intrinsic characterization of the rhythms is made through the analysis of the firing rate of the corresponding action potentials. The discharges were extracellularly recorded in the isolated 6th abdominal ganglion (AG) in an organ culture kept at constant temperature for up to 5 days. For preparations kept in the dark, spontaneous activity varies in a circadian manner, with a period of 24.7 h and the acrophase at subjective nighttime (2140). For light-induced activity, pulses of constant intensity applied regularly throughout the 24-h cycle show that the firing rate at peak and latency vary rhythmically. The period for this rhythm is 24.24 h and the acrophase is at subjective dawn (0326). Additionally, an ultradian rhythm of a approximately 12-h period was observed for both rhythms. When tested with light pulses of different intensities, the CPR responsiveness at night is almost one log unit greater than in daytime. The effect of temperature on both activities is also described. The phase-shift caused by temperature for these circadian rhythms depends on the application time. These results show that the 6th AG is capable of generating a circadian rhythm of electrical activity in the CPR, which in turn is likely to be part of the crayfish circadian system. A possible interaction of different pacemakers forming the distributed circadian system is also discussed. The role of serotonin as a possible modulator of the CPR electrical activity is documented. In addition, the level of the 5-HT(1A) receptors displays a diurnal rhythm in the 6th AG

  16. Conservation status of North American freshwater crayfish (Decapoda: Cambaridae) from the southern United States

    USGS Publications Warehouse

    Loughman, Zachary J.; Welsh, Stuart; Fetzner, James W.; Thoma, Roger F.

    2015-01-01

    A list is provided of all crayfishes (family Cambaridae) in the southern United States, which includes common names, global conservation status, an alternative review of the conservation status based on the IUCN red list criteria, and state distribution. This list includes 357 native crayfishes, of which 12 (3.4%) are critically endangered, 37 (10.4%) are endangered, 126 (35.3%) are vulnerable, 181 (50.7%) are lower risk, and 1 (0.3%) is not evaluated. The leading factors causing imperilment are restricted ranges caused by anthropogenic impacts from changes in land use, contaminants, invasion by non-indigenous species, and habitat fragmentation. In order to conserve and manage diversity of native crayfish, consistency is needed in determining conservation status and more complete distribution and life history information are needed for about 60% of species.

  17. Crayfish feeding responses to zebra mussels depend on microorganisms and learning.

    PubMed

    Hazlett, B A

    1994-10-01

    Three species of crayfish (Orconectes virilis, O. rusticus, andCambarus robustus) were tested for feeding responses to potential food odors from mollusks (either zebra mussels,Dreissena polymorpha, or native gastropods). In all three crayfish species, feeding responses to odor cues were shown only by individuals experienced with feeding on a prey type. Individuals exposed to just the smell of prey organisms did not show feeding responses, indicating the role of associative learning in diet breadth. Establishment of a learned association took more than one feeding experience but once established lasted more than three weeks. When microbial enzymatic degradation of food protein was eliminated, either by UV radiation or microfiltration, feeding responses were eliminated even for crayfish experienced with a prey type.

  18. Effects of predators on fish and crayfish survival in intermittent streams

    USGS Publications Warehouse

    Dekar, Matthew P.; Magoulick, Daniel D.

    2013-01-01

    Predation from aquatic and terrestrial predators arc important factors structuring the size and depth distribution of aquatic prey. We conducted mesocosm and tethering experiments on Little Mulberry Creek in northwest Arkansas during low flows to examine the effects of predators on fish and crayfish survival in intermittent streams Using shallow artificial pools (10 cm deep) and predator exclusions, we tested the hypothesis that large-bodied fish are at greater risk from terrestrial predators in shallow habitats compared to small-bodied individuals. Twenty-four circular pools (12 open top. 12 closed top) were stocked with two size classes of Campostoma anomalum (Central Stonerller) and deployed systematically in a single stream pool. In addition, we used a crayfish tethering experiment to test the hypothesis that the survival of small and large crayfish is greater in shallow and deep habitats, respectively. We tethered two size classes of Orconectes meeki meeki (Meek's Crayfish) along shallow and deep transects in two adjacent stream pools and measured survival for 15 days. During both experiments, we monitored the presence or absence of predators by visual observation and from scat surveys. We demonstrated a negative effect of terrestrial predators on Central Stonerller survival in the artificial pools, and larger individuals were more susceptible to predation. In contrast, small crayfish experienced low survival at all depths and large crayfish were preyed upon much less intensively during the tethering study, particularly in the pool with larger substrate. More studies are needed to understand how stream drying and environmental heterogeneity influence the complex interactions between predator and prey populations in intermittent streams.

  19. Experimental inoculation of Louisiana red swamp crayfish Procambarus clarkii with white spot syndrome virus (WSSV).

    PubMed

    Pace, Barcley T; Hawke, John P; Subramanian, Ramesh; Green, Christopher C

    2016-07-01

    The red swamp crayfish Procambarus clarkii represents an important aquaculture species responsible for over half of all commercial aquaculture profits in Louisiana, USA. White spot syndrome virus (WSSV) is highly pathogenic in crustacean species and induces mass mortality in aquaculture operations worldwide. Natural outbreaks of WSSV occur yearly in cultured populations of crayfish in Louisiana. The goal of this study was to better understand the infectivity of WSSV in P. clarkii, by determining the minimum lethal dose necessary to initiate infection and to measure the resulting cumulative mortality following infection with different doses. A real time quantitative PCR (qPCR) method was used to detect WSSV in DNA extracted from gill tissue to ensure P. clarkii study populations were WSSV-free before the start of trials. Viable viral particles were isolated from naturally infected P. clarkii gill tissue and quantified using a novel digital PCR approach. Three infectivity trials were performed, and WSSV inocula were created by serial dilution, generating 5 treatments per trial. Five crayfish (weighing ~25 g) per dilution per trial received viral inoculations. Mortality was monitored daily for the duration of the trial in order to construct a median lethal dose (LD50) curve, and probit regression analysis was used to determine LD50 concentrations of viral particles. Knowledge of the infectivity of WSSV in native crayfish populations is of critical importance to the management of the commercial crayfish aquaculture industry in Louisiana. This is the first study to investigate the infectivity and to determine the LD50 of the Louisiana strain of WSSV in native crayfish. PMID:27409237

  20. Calcium transport mechanism in molting crayfish revealed by microanalysis

    SciTech Connect

    Mizuhira, V.; Ueno, M.

    1983-01-01

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

  1. Response Function of the Crayfish Caudal Photoreceptor to Hydrodynamic Stimuli

    NASA Astrophysics Data System (ADS)

    Breite, Sally; Bahar, Sonya; Neiman, Alexander; Moss, Frank

    2002-03-01

    In its abdominal 6th ganglion the crayfish houses 2 light-sensitive neurons (caudal photoreceptors, or CPRs). It is known that these neurons work in tandem with a mechanosensory system of tiny hairs spread across the tailfan, which make synaptic contact with the photoreceptors. A stochastic resonance effect has been shown in this system in which light enhances the transduction of a weak, periodic mechanosensory (hydrodynamic) stimulus. It is not known, however, whether an optimal response from the CPR is induced by a single sine wave cycle or some other waveform. We have experimentally investigated this favorable waveform by driving a tailfan preparation with mechanical 10 Hz correlated Ornstein-Uhlenbeck noise and calculating the response function from the spike-triggered average of the applied noise waveform. We will discuss differences in the shape of the optimal waveform under dark and light conditions, as well as what seems to be a noticeable difference in the magnitude of the animals' response to a noisy stimulus in comparison with a periodic stimulus.

  2. Dichroism of Photosensitive Pigment in Rhabdoms of the Crayfish Orconectes

    PubMed Central

    Waterman, Talbot H.; Fernández, Hector R.; Goldsmith, Timothy H.

    1969-01-01

    Microspectrophotometric measurements of isolated crayfish rhabdoms illuminated transversely show that their photosensitive absorption exhibits a dichroic ratio of 2 in situ. The major absorption axis matches the axial direction of the closely parallel microvilli comprising the receptor organelle. Since these microvilli are regularly oriented transversely in about 24 layers, with the axes of the microvilli at 90° in alternate layers, transverse illumination of a properly oriented rhabdom displays alternate dichroic and isotropic bands. Because all the microvilli from any one cell share the same orientation, the layers of microvilli constitute two sets of orthogonal polarization analyzers when illuminated along the normal visual axis. Furthermore, since the dichroic ratio is 2 and transverse absorption in isotropic bands is the same as that in the minor absorbing axis of dichroic bands, the simplest explanation of the analyzer action is that the absorbing dipoles of the chromophores, as in rod and cone outer segments, lie parallel to the membrane surface but are otherwise randomly oriented. The rhabdom's functional dichroism thus arises from its specific fine structural geometry. PMID:5806598

  3. Dichroism of photosensitive pigment in rhabdoms of the crayfish Orconectes.

    PubMed

    Waterman, T H; Fernández, H R; Goldsmith, T H

    1969-09-01

    Microspectrophotometric measurements of isolated crayfish rhabdoms illuminated transversely show that their photosensitive absorption exhibits a dichroic ratio of 2 in situ. The major absorption axis matches the axial direction of the closely parallel microvilli comprising the receptor organelle. Since these microvilli are regularly oriented transversely in about 24 layers, with the axes of the microvilli at 90 degrees in alternate layers, transverse illumination of a properly oriented rhabdom displays alternate dichroic and isotropic bands. Because all the microvilli from any one cell share the same orientation, the layers of microvilli constitute two sets of orthogonal polarization analyzers when illuminated along the normal visual axis. Furthermore, since the dichroic ratio is 2 and transverse absorption in isotropic bands is the same as that in the minor absorbing axis of dichroic bands, the simplest explanation of the analyzer action is that the absorbing dipoles of the chromophores, as in rod and cone outer segments, lie parallel to the membrane surface but are otherwise randomly oriented. The rhabdom's functional dichroism thus arises from its specific fine structural geometry.

  4. Mitochondrial phylogeography of New Zealand freshwater crayfishes, Paranephrops spp.

    PubMed

    Apte, S; Smith, P J; Wallis, G P

    2007-05-01

    Tectonic movement at the boundary of the Indo-Australian and Pacific Plates during the Miocene and Pliocene is recognized as a driving force for invertebrate speciation in New Zealand. Two endemic freshwater crayfish (koura) species, Paranephrops planifrons White 1842 and Paranephrops zealandicus White 1842, represent good model taxa to test geological hypotheses because, due to their low dispersal capacity and life history, geographical restriction of populations may be caused by vicariant processes. Analysis of a mitochondrial DNA marker (cytochrome oxidase subunit I) reveals not two, but three major koura lineages. Contrary to expectation, the cryptic West Coast group appears to be more closely related to P. zealandicus than to P. planifrons and has diverged earlier than the final development (Late Pleistocene) of Cook Strait. Our date estimates suggest that koura lineage diversification probably coincided with early to mid-Alpine orogeny in the mid-Pliocene. Estimates of node ages and the phylogenies are inconsistent with both ancient Oligocene and recent postglacial Pleistocene range expansion, but suggest central to north colonization of North Island and west to east movement in South Island during mid- to late Pliocene. Crypsis and paraphyly of the West Coast group suggest that morphological characters presently used to classify koura species could be misleading. PMID:17444900

  5. Acute toxicity and accumulation of zinc in the crayfish, Orconectes virilis (Hagen)

    SciTech Connect

    Not Available

    1986-09-01

    Zinc produces acute toxicity to freshwater organisms over a range of concentrations from 90 to 58, 100..mu..g Zn/L; with the range of acute median effect concentrations being similar for freshwater fish and invertebrates. The capacity to regulate internal zinc concentrations in decapod crustaceans has been described. Studies with the crayfish Austropotambius pallipes suggested a relatively high degree of tolerance to zinc by this animal. The present study is designed to describe the toxicity of zinc to the crayfish Orconectes virilis over a 2-wk exposure period. In addition, whole animal and tissue analyses were performed on the test organisms and compared to previous results.

  6. Juvenile Confinement in Context

    ERIC Educational Resources Information Center

    Mendel, Richard A.

    2012-01-01

    For more than a century, the predominant strategy for the treatment and punishment of serious and sometimes not-so-serious juvenile offenders in the United States has been placement into large juvenile corrections institutions, alternatively known as training schools, reformatories, or youth corrections centers. America's heavy reliance on…

  7. Juvenile nasopharyngeal angiofibroma.

    PubMed

    Karthikeya, Patil; Mahima, V G; Bagewadi, Shivanand B

    2005-01-01

    Juvenile nasopharyngeal angiofibroma is a rare, histologically benign yet locally aggressive, vascular tumor that typically affects adolescent males. It accounts for 0.5 percent of all neoplasms of the head and neck. A case of juvenile nasopharyngeal angiofibroma manifesting in the oral cavity in a 20-year-old male patient is presented and discussed.

  8. Renewing Juvenile Justice

    ERIC Educational Resources Information Center

    Macallair, Daniel; Males, Mike; Enty, Dinky Manek; Vinakor, Natasha

    2011-01-01

    The Center on Juvenile and Criminal Justice (CJCJ) was commissioned by Sierra Health Foundation to critically examine California's juvenile justice system and consider the potential role of foundations in promoting systemic reform. The information gathered by CJCJ researchers for this report suggests that foundations can perform a key leadership…

  9. Microsatellite markers for direct genotyping of the crayfish plague pathogen Aphanomyces astaci (Oomycetes) from infected host tissues.

    PubMed

    Grandjean, Frédéric; Vrålstad, Trude; Diéguez-Uribeondo, Javier; Jelić, Mišel; Mangombi, Joa; Delaunay, Carine; Filipová, Lenka; Rezinciuc, Svetlana; Kozubíková-Balcarová, Eva; Guyonnet, Daniel; Viljamaa-Dirks, Satu; Petrusek, Adam

    2014-06-01

    Aphanomyces astaci is an invasive pathogenic oomycete responsible for the crayfish plague, a disease that has devastated European freshwater crayfish. So far, five genotype groups of this pathogen have been identified by applying random amplified polymorphic DNA analysis on axenic cultures. To allow genotyping of A. astaci in host tissue samples, we have developed co-dominant microsatellite markers for this pathogen, tested them on pure cultures of all genotype groups, and subsequently evaluated their use on tissues of (1) natural A. astaci carriers, i.e., North American crayfish species, and (2) A. astaci-infected indigenous European species from crayfish plague outbreaks. Out of over 200 potential loci containing simple sequence repeat (SSR) motifs identified by 454 pyrosequencing of SSR-enriched library, we tested 25 loci with highest number of repeats, and finally selected nine that allow unambiguous separation of all known RAPD-defined genotype groups of A. astaci from axenic cultures. Using these markers, we were able to characterize A. astaci strains from DNA isolates from infected crayfish tissues when crayfish had a moderate to high agent level according to quantitative PCR analyses. The results support the hypothesis that different North American crayfish hosts carry different genotype groups of the pathogen, and confirm that multiple genotype groups, including the one originally introduced to Europe in the 19th century, cause crayfish plague outbreaks in Central Europe. So far undocumented A. astaci genotype seems to have caused one of the analysed outbreaks from the Czech Republic. The newly developed culture-independent approach allowing direct genotyping of this pathogen in both axenic cultures and mixed genome samples opens new possibilities in studies of crayfish plague pathogen distribution, diversity and epidemiology.

  10. The complete mitogenome of the Australian spiny crayfish Euastacus yarraensis (McCoy, 1888) (Crustacea: Decapoda: Parastacidae).

    PubMed

    Gan, Han Ming; Tan, Mun Hua; Austin, Christopher M

    2016-01-01

    The mitochondrial genome sequence of the Australian crayfish, Euastacus yarraensis, is documented and compared with other Australian crayfish genera. Euastacus yarraensis has a mitogenome of 15,548 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a non-coding AT-rich region. The base composition of E. yarraensis mitogenome is 32.39% for T, 22.45% for C, 34.43% for A, and 10.73% for G, with an AT bias of 66.82%. The mitogenome gene order conforms to what is considered the primitive arrangement for parastacid crayfish.

  11. Zinc, iron, manganese, and magnesium accumulation in crayfish populations near copper-nickel smelters at Sudbury, Ontario, Canada

    SciTech Connect

    Bagatto, G.; Alikhan, M.A.

    1987-06-01

    The Sudbury basin has been subjected to extreme ecological disturbances from logging, mining and smelting activities. Elevated concentrations of copper, cadmium, and nickel have been reported in crayfish populations close to the Sudbury smelting works. The present study compares concentrations of zinc (Zn), iron (Fe), manganese (Mn) and magnesium (Mg) in freshwater crayfish at selected distances of the habitat from the emission source. These metals were selected since they are known to be emitted in moderately high quantities into the Sudbury environment as byproduct of the smelting process. Various tissue concentrations in crayfish were also examined to determined specific tissue sites for these accumulations.

  12. Effects of predation risk on habitat selection by water column fish, benthic fish and crayfish in stream pools

    USGS Publications Warehouse

    Magoulick, D.D.

    2004-01-01

    Predation risk can affect habitat selection by water column stream fish and crayfish, but little is known regarding effects of predation risk on habitat selection by benthic fish or assemblages of fish and crayfish. I used comparative studies and manipulative field experiments to determine whether, (1) habitat selection by stream fish and crayfish is affected by predation risk, and (2) benthic fish, water column fish, and crayfish differ in their habitat selection and response to predation risk. Snorkeling was used to observe fish and crayfish in, (1) unmanipulated stream pools with and without large smallmouth bass predators (Micropterus dolomieui >200 mm total length, TL) and (2) manipulated stream pools before and after addition of a single large smallmouth bass, to determine if prey size and presence of large fish predators affected habitat selection. Observations of microhabitat use were compared with microhabitat availability to determine microhabitat selection. Small fish (60-100 mm TL, except darters that were 30-100 mm TL) and crayfish (40-100 mm rostrum to telson length; TL) had significantly reduced densities in pools with large bass, whereas densities of large fish and crayfish (> 100 mm TL) did not differ significantly between pools with and without large bass. Small orangethroat darters (Etheostoma spectabile), northern crayfish (Orconectes virilis), and creek chubs (Semotilus atromaculatus) showed significantly greater densities in pools without large bass. The presence of large smallmouth bass did not significantly affect depths selected by fish and crayfish, except minnows, which were found significantly more often at medium depths when bass were present. Small minnows and large and small crayfish showed the greatest response to additions of bass to stream pools by moving away from bass locations and into shallow water. Small darters and sunfish showed an intermediate response, whereas large minnows showed no significant response to bass additions

  13. Electrophysiological Evidence for Intrinsic Pacemaker Currents in Crayfish Parasol Cells

    PubMed Central

    Mellon, DeForest

    2016-01-01

    I used sharp intracellular electrodes to record from parasol cells in the semi-isolated crayfish brain to investigate pacemaker currents. Evidence for the presence of the hyperpolarization-activated inward rectifier potassium current was obtained in about half of the parasol cells examined, where strong, prolonged hyperpolarizing currents generated a slowly-rising voltage sag, and a post-hyperpolarization rebound. The amplitudes of both the sag voltage and the depolarizing rebound were dependent upon the strength of the hyperpolarizing current. The voltage sag showed a definite threshold and was non-inactivating. The voltage sag and rebound depolarization evoked by hyperpolarization were blocked by the presence of 5–10 mM Cs2+ ions, 10 mM tetraethyl ammonium chloride, and 10 mM cobalt chloride in the bathing medium, but not by the drug ZD 7288. Cs+ ions in normal saline in some cells caused a slight increase in mean resting potential and a reduction in spontaneous burst frequency. Many of the neurons expressing the hyperpolarization-activated inward potassium current also provided evidence for the presence of the transient potassium current IA, which was inferred from experimental observations of an increased latency of post-hyperpolarization response to a depolarizing step, compared to the response latency to the depolarization alone. The latency increase was reduced in the presence of 4-aminopyridine (4-AP), a specific blocker of IA. The presence of 4-AP in normal saline also induced spontaneous bursting in parasol cells. It is conjectured that, under normal physiological conditions, these two potassium currents help to regulate burst generation in parasol cells, respectively, by helping to maintain the resting membrane potential near a threshold level for burst generation, and by regulating the rate of rise of membrane depolarizing events leading to burst generation. The presence of post-burst hyperpolarization may depend upon IA channels in parasol cells

  14. Photodynamic damage of glial cells in crayfish ventral nerve cord

    NASA Astrophysics Data System (ADS)

    Kolosov, M. S.; Duz, E.; Uzdensky, A. B.

    2010-10-01

    Photodynamic therapy (PDT) is a promising method for treatment of brain tumors, the most of which are of glial origin. In the present work we studied PDT-mediated injury of glial cells in nerve tissue, specifically, in abdominal connectives in the crayfish ventral nerve cord. The preparation was photosensitized with alumophthalocyanine Photosens and irradiated 30 min with the diode laser (670 nm, 0.1 or 0.15 W/cm2). After following incubation in the darkness during 1- 10 hours it was fluorochromed with Hoechst 33342 and propidium iodide to reveal nuclei of living, necrotic and apoptotic cells. The chain-like location of the glial nuclei allowed visualization of those enveloping giant axons and blood vessels. The level of glial necrosis in control preparations was about 2-5 %. Apoptosis was not observed in control preparations. PDT significantly increased necrosis of glial cells to 52 or 67 % just after irradiation with 0.1 or 0.15 W/cm2, respectively. Apoptosis of glial cells was observed only at 10 hours after light exposure. Upper layers of the glial envelope of the connectives were injured stronger comparing to deep ones: the level of glial necrosis decreased from 100 to 30 % upon moving from the connective surface to the plane of the giant axon inside the connective. Survival of glial cells was also high in the vicinity of blood vessels. One can suggest that giant axons and blood vessels protect neighboring glial cells from photodynamic damage. The mechanism of such protective action remains to be elucidated.

  15. Photodynamic damage of glial cells in crayfish ventral nerve cord

    NASA Astrophysics Data System (ADS)

    Kolosov, M. S.; Duz, E.; Uzdensky, A. B.

    2011-03-01

    Photodynamic therapy (PDT) is a promising method for treatment of brain tumors, the most of which are of glial origin. In the present work we studied PDT-mediated injury of glial cells in nerve tissue, specifically, in abdominal connectives in the crayfish ventral nerve cord. The preparation was photosensitized with alumophthalocyanine Photosens and irradiated 30 min with the diode laser (670 nm, 0.1 or 0.15 W/cm2). After following incubation in the darkness during 1- 10 hours it was fluorochromed with Hoechst 33342 and propidium iodide to reveal nuclei of living, necrotic and apoptotic cells. The chain-like location of the glial nuclei allowed visualization of those enveloping giant axons and blood vessels. The level of glial necrosis in control preparations was about 2-5 %. Apoptosis was not observed in control preparations. PDT significantly increased necrosis of glial cells to 52 or 67 % just after irradiation with 0.1 or 0.15 W/cm2, respectively. Apoptosis of glial cells was observed only at 10 hours after light exposure. Upper layers of the glial envelope of the connectives were injured stronger comparing to deep ones: the level of glial necrosis decreased from 100 to 30 % upon moving from the connective surface to the plane of the giant axon inside the connective. Survival of glial cells was also high in the vicinity of blood vessels. One can suggest that giant axons and blood vessels protect neighboring glial cells from photodynamic damage. The mechanism of such protective action remains to be elucidated.

  16. Electrophysiological Evidence for Intrinsic Pacemaker Currents in Crayfish Parasol Cells.

    PubMed

    Mellon, DeForest

    2016-01-01

    I used sharp intracellular electrodes to record from parasol cells in the semi-isolated crayfish brain to investigate pacemaker currents. Evidence for the presence of the hyperpolarization-activated inward rectifier potassium current was obtained in about half of the parasol cells examined, where strong, prolonged hyperpolarizing currents generated a slowly-rising voltage sag, and a post-hyperpolarization rebound. The amplitudes of both the sag voltage and the depolarizing rebound were dependent upon the strength of the hyperpolarizing current. The voltage sag showed a definite threshold and was non-inactivating. The voltage sag and rebound depolarization evoked by hyperpolarization were blocked by the presence of 5-10 mM Cs2+ ions, 10 mM tetraethyl ammonium chloride, and 10 mM cobalt chloride in the bathing medium, but not by the drug ZD 7288. Cs+ ions in normal saline in some cells caused a slight increase in mean resting potential and a reduction in spontaneous burst frequency. Many of the neurons expressing the hyperpolarization-activated inward potassium current also provided evidence for the presence of the transient potassium current IA, which was inferred from experimental observations of an increased latency of post-hyperpolarization response to a depolarizing step, compared to the response latency to the depolarization alone. The latency increase was reduced in the presence of 4-aminopyridine (4-AP), a specific blocker of IA. The presence of 4-AP in normal saline also induced spontaneous bursting in parasol cells. It is conjectured that, under normal physiological conditions, these two potassium currents help to regulate burst generation in parasol cells, respectively, by helping to maintain the resting membrane potential near a threshold level for burst generation, and by regulating the rate of rise of membrane depolarizing events leading to burst generation. The presence of post-burst hyperpolarization may depend upon IA channels in parasol cells. PMID

  17. THREE-DIMENSIONAL ULTRASTRUCTURE OF THE CRAYFISH NEUROMUSCULAR APPARATUS

    PubMed Central

    Jahromi, S. S.; Atwood, H. L.

    1974-01-01

    The synapse-bearing nerve terminals of the opener muscle of the crayfish Procambarus were reconstructed using electron micrographs of regions which had been serially sectioned. The branching patterns of the terminals of excitatory and inhibitory axons and the locations and sizes of neuromuscular and axo-axonal synapses were studied. Excitatory and inhibitory synapses could be distinguished not only on the basis of differences in synaptic vesicles, but also by a difference in density of pre- and postsynaptic membranes. Synapses of both axons usually had one or more sharply localized presynaptic "dense bodies" around which synaptic vesicles appeared to cluster. Some synapses did not have the dense bodies. These structures may be involved in the physiological activity of the synapse. Excitatory axon terminals had more synapses, and a larger percentage of terminal surface area devoted to synaptic contacts, than inhibitory axon terminals. However, the largest synapses of the inhibitory axon exceeded in surface area those of the excitatory axon. Both axons had many side branches coming from the main terminal; often, the side branches were joined to the main terminal by narrow necks. A greater percentage of surface area was devoted to synapses in side branches than in the main terminal. Only a small fraction of total surface area was devoted to axo-axonal synapses, but these were often located at narrow necks or constrictions of the excitatory axon. This arrangement would result in effective blockage of spike invasion of regions of the terminal distal to the synapse, and would allow relatively few synapses to exert a powerful effect on transmitter release from the excitatory axon. A hypothesis to account for the development of the neuromuscular apparatus is presented, in which it is suggested that production of new synapses is more important than enlargement of old ones as a mechanism for allowing the axon to adjust transmitter output to the functional needs of the muscle

  18. Zoogeography, taxonomy, and conservation of West Virginia's Ohio River floodplain crayfishes (Decapoda, Cambaridae).

    PubMed

    Loughman, Zachary J; Simon, Thomas P

    2011-01-01

    The crayfish fauna of West Virginia consists of 23 species and several undescribed taxa. Most survey efforts documenting this fauna have been conducted in lotic waterways throughout the Appalachian plateau, Allegheny Mountains, and Ridge and Valley physiographic provinces. Bottomland forests, swamps, and marshes associated with large river floodplain such as the Ohio River floodplain historically have been under-surveyed in the state. These habitats harbor the richest primary burrowing crayfish fauna in West Virginia, and are worthy of survey efforts. In an effort to fill this void, the crayfish fauna of West Virginia's Ohio River floodplain was surveyed from 2004 through 2009. From this survey, nine species from four genera were documented inhabiting the floodplain. Zoogeography, biology, and conservation status is provided for all nine crayfishes. The dominant genus along the floodplain is Cambarus, which includes Cambarus (Cambarus) carinirostris, Cambarus (Cambarus) bartonii cavatus, Cambarus (Procambarus) robustus and Cambarus (Tubericambarus) thomai. Cambarus (Tubericambarus) thomai is the most prevalent burrowing species occurring along the floodplain. The genus Orconectes consists of two native species, Orconectes (Cambarus) obscurus and Orconectes (Cambarus) sanbornii; and two invasive taxa, Orconectes (Gremicambarus) virilis and Orconectes (Procambarus) rusticus. Orconectes (Cambarus) obscurus has experienced a range extension to the south and occupies streams formerly occupied by Orconectes (Cambarus) sanbornii. Both invasive taxa were allied with anthropogenic habitats and disturbance gradients. The genera Fallicambarus and Procambarus are represented by a single species. Both Fallicambarus (Cambarus) fodiens and Procambarus (Orconectes) acutus are limited to the historic preglacial Marietta River Valley. PMID:21594135

  19. Human paragonimiasis after eating raw or undercooked crayfish --- Missouri, July 2006-September 2010.

    PubMed

    2010-12-10

    Paragonimiasis is a parasitic disease caused by Paragonimus trematodes, commonly known as lung flukes. Humans become infected by eating raw or undercooked crayfish (also known as crawfish and crawdads) or freshwater crabs that harbor the parasites. Paragonimiasis most frequently involves the lungs, but can affect other organs, including the brain and skin. In North America, Paragonimus kellicotti causes infections among dogs, cats, and wild carnivores, but rarely infects humans. Paragonimiasis is not a nationally notifiable condition. In September 2009, physicians from the Washington University School of Medicine (WUSM) in St. Louis published details of three paragonimiasis cases diagnosed since July 2006 in persons who had eaten raw crayfish from rivers in Missouri, prompting the Missouri Department of Health and Senior Services (MDHSS), CDC, and WUSM to collaborate in paragonimiasis surveillance and prevention. During September 2009-September 2010, six additional cases were diagnosed in Missouri. These nine patients, aged 10-32 years, had fever, cough, pleural effusion, and eosinophilia. All had eaten raw or undercooked crayfish from rivers in Missouri while on canoeing or camping trips within 4 months of illness onset. Health-care providers should consider paragonimiasis when examining patients with unexplained fever, cough, eosinophilia, and pleural effusion or other chest radiographic abnormalities and should ask those patients whether they have eaten raw or undercooked crayfish.

  20. 76 FR 79209 - Proposed Safe Harbor Agreement for the Shasta Crayfish in Cassel, Shasta County, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-21

    ... applicable legal requirements, and consistent with the Service's Safe Harbor Policy (64 FR 32717), the... Fish and Wildlife Service Proposed Safe Harbor Agreement for the Shasta Crayfish in Cassel, Shasta... agreement (agreement) between the ] applicant and the Service for the federally endangered Shasta...

  1. Characterizing the Invasion Front of the Rusty Crayfish, Orconectes Rusticus, in a Pennsylvania Stream

    NASA Astrophysics Data System (ADS)

    Wagner, J. M.; Wallace, J. R.; Perry, W. L.

    2005-05-01

    The rusty crayfish, Orconectes rusticus, was an unknown species in Pennsylvania during the last major assessment of crayfish as documented in a 1906 survey. An intensive survey of Lancaster County, Pennsylvania in 2000 revealed that O. rusticus had successfully invaded many streams. Orconectes rusticus are also sold in local bait shops suggesting its introduction was likely due to its use as bait. Orconectes rusticus has the potential to cause serious ecological harm to aquatic systems by displacing native crayfish species via competition and hybridization leading to alteration of food web dynamics. In order to predict the extent of invasions, identification of the physical and chemical parameters predisposing stream habitats to invasion is needed. Our objectives were to determine how a suite of physical and chemical parameters might influence the distribution of crayfish species along a stream continuum, with particular emphasis on characterizing the invasion front of Orconectes rusticus. Rather than an invasion front, we encountered a distinct invasion boundary created by a natural series of small waterfalls. Our data suggest that parameters such as water velocity, depth, pH, and temperature have little effect on the distribution and invasion of Orconectes rusticus along a stream continuum when natural barriers are present.

  2. Determination of lead in treated crayfish Procambarus clarkii: accumulation in different tissues

    SciTech Connect

    Pastor, A.; Medina, J.; Del Ramo, J.; Torreblanca, A.; Diaz-Mayans, J.; Hernandez, F.

    1988-09-01

    The continual loading of trace metals into our environment represents a water pollution problem due to their toxic effects on aquatic biota. In addition, metal ions can be incorporated into food chains and concentrated by aquatic organisms to a level that affects their physiological state. There are several investigations on the toxic effects and bioaccumulation of lead in fishes, molluscs, and crustaceans. Lake Albufera (Valencia, Spain) and the surrounding rice-field waters are subjected to large loads of sewage and toxic industrial residues (including heavy metals) from many urban wastewaters in the area. In 1978, the American red crayfish Procambarus clarkii (Girard) appeared in Lake Albufera. The crayfish have reached a high density producing ecological and agricultural economic problems in rice crops. The crayfish is being fished commercially for human consumption without adequate protection to human health. The purpose of the present study was to investigate the accumulation of lead in tissues of the crayfish P. clarkii following short term lead exposure at several sublethal concentrations. The gills, midgut glands, antennal glands and muscle were analyzed by atomic absorption spectrophotometry.

  3. Genotypic analyses and virulence characterization of Listeria monocytogenes isolates from crayfish (Procambarus clarkii).

    PubMed

    Li, Jinquan; Du, Pujun; Li, Zhi; Zhou, Yang; Cheng, Wei; Wu, Si; Chen, Fusheng; Wang, Xiaohong

    2015-05-01

    Listeria monocytogenes is a foodborne pathogen that can cause invasive illness in humans and farm animals. It is frequently isolated from dairy products and poultry. However, there have been few literatures on the genetic diversity and virulence potential of L. monocytogenes from freshwater animal. Thirty-nine L. monocytogenes strains from crayfish were isolated and identified in this study. Molecular subtyping and polymorphism of each isolate were analyzed by multilocus sequence typing (MLST). MLST divided the isolates into eight sequence types (STs), six of which from crayfish were the same with the isolates from environment and clinic. PCR detection of the eight genes related to virulence and multiplex PCR for serotyping showed that the eight virulence factors were present in the isolates and all the isolates belonged to four major L. monocytogenes serotype groups (1/2a, 1/2b, 1/2c, and 4b) frequently isolated from patients. In vivo pathogenicity of isolates was also evaluated in murine model and survival curve of infected mice suggested that ST1, ST4, and ST9 isolates were as virulent as the reference strain EGDe. This study provides preliminary insights into the genetic diversity of L. monocytogenes from crayfish and the genetic correlation between crayfish and clinical L. monocytogenes isolates. The results indicate the contamination in aquaculture could be the source of Listeria contamination and the isolates are likely to cause human listeriosis.

  4. Ionoregulatory responses of the crayfish Orconectes immunis to selenium in fresh water

    SciTech Connect

    Short, T.M.

    1983-01-01

    The purpose of this study was to investigate the effects of chronic exposure to sublethal concentrations of selenium on fluid and tissue electrolyte balance of the crayfish Orconcectes immunis. An ionic profile of O. immunis was obtained from measurements of hemolymph sodium, potassium, calcium, magnesium, and copper in several populations of crayfish in eastern Colorado. The bioassay portion of the study consisted of groups of crayfish maintained in reconstituted fresh water while exposed for 30 days to concentrations of 0.01 mg/liter, 0.10 mg/liter, or 1.00 mg/liter selenium as sodium selenite. Exposure to selenium resulted in various branchial histopathologies to include hypertrophy, necrosis, and sloughing of the cuticular membrane. Hemolymph potassium and copper, however, were significantly reduced in crayfish exposed for 10 days to 1.00 mg/liter selenium and 30 days to 0.10 mg/liter selenium. Copper appeared to be the more responsive to selenium toxicity with reductions of 47.4%-53.7% in hemolymph levels after exposure for 30 days to 1.00 mg/liter selenium. Selenium-induced changes in tissue ionic content (abdominal muscle and carapace) were most evident with respect to muscle levels of potassium and calcium. It is suggested that the observed alterations in fluid and tissue ionic content are largely in response to changes in concentration or electrochemical potential gradients brought about by selenium-induced disturbance of membrance permeability and ionic transport characteristics.

  5. Cadmium accumulation in the crayfish, Procambarus clarkii, using graphite furnace atomic absorption spectroscopy

    SciTech Connect

    Diaz-Mayans, J.; Hernandez, F.; Medina, J.; Del Ramo, J.; Torreblanca, A.

    1986-11-01

    Lake Albufera and the surrounding rice-field waters are being subject to very heavy loads of sewage and toxic industrial residues (including heavy metals and pesticides) from the many urban and wastewaters in this area. The American red crayfish Procambarus clarkii is native to the Louisiana marshes (USA). In 1978, the crayfish appeared in Lake Albufera near Valencia (Spain), and presently, without adequate sanitary controls, the crayfish is being fished commercially for human consumption. In view of this interest, it is important to have accurate information on concentrations of cadmium in natural waters and cadmium levels of tissues of freshwaters animals used as human food, as well as the accumulation rates of this metal in this animal. In the present study, the authors investigated the accumulation of cadmium in several tissues of the red crayfish, P clarkii (Girard) from Lake Albufera following cadmium exposure. Determinations of cadmium were made by flameless atomic absorption spectroscopy and the standard additions method. Digestion of samples was made by wet ashing in open flasks with concentrated HNO/sub 3/ at 80-90/sup 0/C.

  6. Occupancy rates of primary burrowing crayfish in natural and disturbed large river bottomlands

    USGS Publications Warehouse

    Loughman, Zachary J.; Welsh, Stuart; Simon, Thomas P.

    2012-01-01

    Among crayfish, primary burrowing species are the least understood ecologically. Many primary burrowing crayfish inhabit floodplains where forested landscapes have been fragmented by agricultural, industrial, or residential uses. In this study, site occupancy rates (ψ) were modeled for two primary burrowing crayfish, Fallicambarus fodiens (Cottle, 1863) and Cambarus thomai Jezerinac, 1993, from Ohio and Kanawha river floodplains in West Virginia, U.S.A. Fallicambarus fodiens is one of West Virginia’s rarest crayfish, while C. thomai is prevalent in most wetlands along both river floodplains. Occupancy rate modeling incorporated four environmental covariates (forest age, soil type, tree frequency, and land use). Based on presence/absence data, forests with tree ages >100 years (ΔQAICc = 0) and sites with loam soils (ΔQAICc = 1.80) were most likely to harbor F. fodiens populations. For C. thomai, several models were supported owing to model selection uncertainty, but those with the land use covariate had more total model weight (total w i = 0 . 54 ) than all other covariate models. Cambarus thomai rarely occupied industrial/agricultural sites, but were often present in forested and residential sites. Although the influence of covariates on site occupancy differed between species, both taxa readily utilized mature forested habitats when available. Conservation actions for F. fodiens and C. thomai should focus on preserving forested tracts along large river floodplains

  7. A comparison of two gears for quantifying abundance of lotic-dwelling crayfish

    USGS Publications Warehouse

    Williams, Kristi; Brewer, Shannon K.; Ellersieck, Mark R.

    2014-01-01

    Crayfish (saddlebacked crayfish, Orconectes medius) catch was compared using a kick seine applied two different ways with a 1-m2 quadrat sampler (with known efficiency and bias in riffles) from three small streams in the Missouri Ozarks. Triplicate samples (one of each technique) were taken from two creeks and one headwater stream (n=69 sites) over a two-year period. General linear mixed models showed the number of crayfish collected using the quadrat sampler was greater than the number collected using either of the two seine techniques. However, there was no significant interaction with gear suggesting year, stream size, and channel unit type did not relate to different catches of crayfish by gear type. Variation in catch among gears was similar, as was the proportion of young-of-year individuals across samples taken with different gears or techniques. Negative binomial linear regression provided the appropriate relation between the gears which allows correction factors to be applied, if necessary, to relate catches by the kick seine to those of the quadrat sampler. The kick seine appears to be a reasonable substitute to the quadrat sampler in these shallow streams, with the advantage of ease of use and shorter time required per sample.

  8. Dietary chitosan nanoparticles protect crayfish Procambarus clarkii against white spot syndrome virus (WSSV) infection.

    PubMed

    Sun, Baozhen; Quan, Haizhi; Zhu, Fei

    2016-07-01

    Chitosan nanoparticles have exhibited potential antibacterial activity or anticancer activity as their unique character. In this study, we investigated the effect of chitosan nanoparticles protect crayfish Procambarus clarkii against WSSV. Chitosan (from crab shell) nanoparticles were prepared by ultrafine milling. The physicochemical properties of the nanoparticles were determined by particle size measure, zeta potential analysis and scanning electron microscope observation. The total hemocyte count (THC), phenoloxidase (PO) and superoxide dismutase (SOD) activity were measured at days 1, 4, 9 and 12, and the survival rate was also recorded after WSSV challenge. The results showed that chitosan nanoparticles could enhance the survival rate of WSSV-challenged crayfish. And crayfish fed diets supplemented with 10 mg/g chitosan nanoparticles (65% mortality) showed a significantly higher survival rate when compared to the control group (100% mortality). The analysis of immunological parameters revealed that 10 mg/g chitosan nanoparticles showed significantly higher level of prophenoloxidase (proPO), superoxide dismutase (SOD) and total hemocyte count (THC) when compared to the control group. It was found that chitosan nanoparticles could inhibit WSSV replication in crayfish. Our results demonstrated that dietary chitosan nanoparticles effectively improve innate immunity and survival of P. clarkii challenged with WSSV. PMID:27071520

  9. Dietary chitosan nanoparticles protect crayfish Procambarus clarkii against white spot syndrome virus (WSSV) infection.

    PubMed

    Sun, Baozhen; Quan, Haizhi; Zhu, Fei

    2016-07-01

    Chitosan nanoparticles have exhibited potential antibacterial activity or anticancer activity as their unique character. In this study, we investigated the effect of chitosan nanoparticles protect crayfish Procambarus clarkii against WSSV. Chitosan (from crab shell) nanoparticles were prepared by ultrafine milling. The physicochemical properties of the nanoparticles were determined by particle size measure, zeta potential analysis and scanning electron microscope observation. The total hemocyte count (THC), phenoloxidase (PO) and superoxide dismutase (SOD) activity were measured at days 1, 4, 9 and 12, and the survival rate was also recorded after WSSV challenge. The results showed that chitosan nanoparticles could enhance the survival rate of WSSV-challenged crayfish. And crayfish fed diets supplemented with 10 mg/g chitosan nanoparticles (65% mortality) showed a significantly higher survival rate when compared to the control group (100% mortality). The analysis of immunological parameters revealed that 10 mg/g chitosan nanoparticles showed significantly higher level of prophenoloxidase (proPO), superoxide dismutase (SOD) and total hemocyte count (THC) when compared to the control group. It was found that chitosan nanoparticles could inhibit WSSV replication in crayfish. Our results demonstrated that dietary chitosan nanoparticles effectively improve innate immunity and survival of P. clarkii challenged with WSSV.

  10. Zoogeography, taxonomy, and conservation of West Virginia’s Ohio River floodplain crayfishes (Decapoda, Cambaridae)

    PubMed Central

    Loughman, Zachary J.; Simon, Thomas P.

    2011-01-01

    Abstract The crayfish fauna of West Virginia consists of 23 species and several undescribed taxa. Most survey efforts documenting this fauna have been conducted in lotic waterways throughout the Appalachian plateau, Allegheny Mountains, and Ridge and Valley physiographic provinces. Bottomland forests, swamps, and marshes associated with large river floodplain such as the Ohio River floodplain historically have been under-surveyed in the state. These habitats harbor the richest primary burrowing crayfish fauna in West Virginia, and are worthy of survey efforts. In an effort to fill this void, the crayfish fauna of West Virginia’s Ohio River floodplain was surveyed from 2004 through 2009. From this survey, nine species from four genera were documented inhabiting the floodplain. Zoogeography, biology, and conservation status is provided for all nine crayfishes. The dominant genus along the floodplain is Cambarus, which includes Cambarus (Cambarus) carinirostris, Cambarus (Cambarus) bartonii cavatus, Cambarus (Procambarus) robustus and Cambarus (Tubericambarus) thomai. Cambarus (Tubericambarus) thomai is the most prevalent burrowing species occurring along the floodplain. The genus Orconectes consists of two native species, Orconectes (Cambarus) obscurus and Orconectes (Cambarus) sanbornii; and two invasive taxa, Orconectes (Gremicambarus) virilis and Orconectes (Procambarus) rusticus. Orconectes (Cambarus) obscurus has experienced a range extension to the south and occupies streams formerly occupied by Orconectes (Cambarus) sanbornii. Both invasive taxa were allied with anthropogenic habitats and disturbance gradients. The genera Fallicambarus and Procambarus are represented by a single species. Both Fallicambarus (Cambarus) fodiens and Procambarus (Orconectes) acutus are limited to the historic preglacial Marietta River Valley. PMID:21594135

  11. Reporting Crimes Against Juveniles. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Finkelhor, David; Ormrod, Richard

    This bulletin addresses the issue of reporting crimes against juveniles, describing findings from the National Crime Victimization Survey, which gathers information from citizens on crime, including whether and how they are reported. The survey also collects information about characteristics of victimizations, the nature of the incident location,…

  12. In-depth transcriptome analysis of the red swamp crayfish Procambarus clarkii.

    PubMed

    Shen, Huaishun; Hu, Yacheng; Ma, Yuanchao; Zhou, Xin; Xu, Zenghong; Shui, Yan; Li, Chunyan; Xu, Peng; Sun, Xiaowen

    2014-01-01

    The red swamp crayfish Procambarus clarkii is a highly adaptable, tolerant, and fecund freshwater crayfish that inhabits a wide range of aquatic environments. It is an important crustacean model organism that is used in many research fields, including animal behavior, environmental stress and toxicity, and studies of viral infection. Despite its widespread use, knowledge of the crayfish genome is very limited and insufficient for meaningful research. This is the use of next-generation sequencing techniques to analyze the crayfish transcriptome. A total of 324.97 million raw reads of 100 base pairs were generated, and a total of 88,463 transcripts were assembled de novo using Trinity software, producing 55,278 non-redundant transcripts. Comparison of digital gene expression between four different tissues revealed differentially expressed genes, in which more overexpressed genes were found in the hepatopancreas than in other tissues, and more underexpressed genes were found in the testis and the ovary than in other tissues. Gene ontology (GO) and KEGG enrichment analysis of differentially expressed genes revealed that metabolite- and immune-related pathway genes were enriched in the hepatopancreas, and DNA replication-related pathway genes were enriched in the ovary and the testis, which is consistent with the important role of the hepatopancreas in metabolism, immunity, and the stress response, and with that of the ovary and the testis in reproduction. It was also found that 14 vitellogenin transcripts were highly expressed specifically in the hepatopancreas, and 6 transcripts were highly expressed specifically in the ovary, but no vitellogenin transcripts were highly expressed in both the hepatopancreas and the ovary. These results provide new insight into the role of vitellogenin in crustaceans. In addition, 243,764 SNP sites and 43,205 microsatellite sequences were identified in the sequencing data. We believe that our results provide an important genome resource

  13. Sublethal copper toxicity impairs chemical orientation in the crayfish, Orconectes rusticus.

    PubMed

    Lahman, Sara E; Trent, Kaitlyn R; Moore, Paul A

    2015-03-01

    Before reaching concentrations that are high enough to cause mortality, elevated levels of chemical pollution can significantly alter a keystone indicator species' ability to extract sensory information. To organisms that rely on chemical signals to make crucial ecological decisions, increased amounts of a pollutant may impact chemoreceptive abilities by altering the perception of the sensory landscape or impairing the functioning of sensory organs. Heavy metal pollutants entering an aquatic ecosystem are of increasing concern due to discernible effects on chemoreception in many ecologically and economically important species. In order to determine the effects of sublethal copper toxicity on chemically mediated behavior, male and female rusty crayfish, Orconectes rusticus, were exposed to ecologically relevant concentrations of copper (4.5, 45, and 450 µg/l) for 120 h. Following exposure, crayfish were allowed to orient toward a food odor stimulus. During orientation trials, select crayfish oriented under a point or nonpoint source copper background pollutant at the same concentration as the exposure period. Orientation trials were videotaped and analyzed using EthoVision XT 8.5 (Noldus Information Technology, The Netherlands) for differences in overall success in locating the food source and orienting parameters. Significant differences were found in the overall orientation ability of O. rusticus to locate an odor source when previously exposed to copper in combination with a source of pollution in the background of orientation trials. Crayfish exposed to copper in any capacity during the experiment (regardless of concentration or background during trials) showed slower walking speeds toward the source, decreased turning angles, increased heading angles toward the source, and decreased upstream heading angles. Results from this experiment support that copper impairs the ability of crayfish to detect, process, and/or respond appropriately to chemosensory

  14. The effects of bt corn on rusty crayfish (Orconectes rusticus) growth and survival.

    PubMed

    Linn, Matthew D; Moore, Paul A

    2014-10-01

    Bt crops are one of the most commonly used genetically modified crops worldwide. Bt crops contain a gene that is derived from the bacteria Bacillus thuringiensis, which produces the Cry1Ab toxin. Bt corn that contains the Cry1Ab toxin is used throughout the Midwest United States to control crop pests such as the European corn borer (Ostrinia nubilalis). Headwater streams in regions known for intensive agriculture receive Bt corn detritus after the fall harvest, which is then consumed by a diverse community of stream invertebrates. The rusty crayfish (Orconectes rusticus) is a common invertebrate detritivore in these headwater streams. Both isogenic and Bt corn were grown under the controlled environmental conditions of a greenhouse and, after senescence, were tested for nutritional equality. Rusty crayfish were exposed to one of several detrital treatments composed of Bt corn, Bt corn plus American sycamore (Platanus occidentalis), isogenic corn alone, isogenic corn plus P. occidentalis, or P. occidentalis alone for 8 weeks. Both strains of corn were grown under the controlled environmental conditions in a greenhouse and were tested for nutritional equality after senescence. Crayfish were housed in live streams with a water temperature of 12.8 °C and a 12:12 h light-to-dark photoperiod. Survival and growth of animals within each experimental treatment were monitored each week. After 8 weeks of exposure, there was no statistically significant difference in growth between crayfish in Bt and isogenic treatments. However, survivorship was 31 % lower in the Bt treatment compared with the isogenic treatment. These results suggest that the Bt corn and isogenic corn were of equivalent nutritional value but that Bt corn does have a toxic effect on rusty crayfish during long-term exposure.

  15. The effects of bt corn on rusty crayfish (Orconectes rusticus) growth and survival.

    PubMed

    Linn, Matthew D; Moore, Paul A

    2014-10-01

    Bt crops are one of the most commonly used genetically modified crops worldwide. Bt crops contain a gene that is derived from the bacteria Bacillus thuringiensis, which produces the Cry1Ab toxin. Bt corn that contains the Cry1Ab toxin is used throughout the Midwest United States to control crop pests such as the European corn borer (Ostrinia nubilalis). Headwater streams in regions known for intensive agriculture receive Bt corn detritus after the fall harvest, which is then consumed by a diverse community of stream invertebrates. The rusty crayfish (Orconectes rusticus) is a common invertebrate detritivore in these headwater streams. Both isogenic and Bt corn were grown under the controlled environmental conditions of a greenhouse and, after senescence, were tested for nutritional equality. Rusty crayfish were exposed to one of several detrital treatments composed of Bt corn, Bt corn plus American sycamore (Platanus occidentalis), isogenic corn alone, isogenic corn plus P. occidentalis, or P. occidentalis alone for 8 weeks. Both strains of corn were grown under the controlled environmental conditions in a greenhouse and were tested for nutritional equality after senescence. Crayfish were housed in live streams with a water temperature of 12.8 °C and a 12:12 h light-to-dark photoperiod. Survival and growth of animals within each experimental treatment were monitored each week. After 8 weeks of exposure, there was no statistically significant difference in growth between crayfish in Bt and isogenic treatments. However, survivorship was 31 % lower in the Bt treatment compared with the isogenic treatment. These results suggest that the Bt corn and isogenic corn were of equivalent nutritional value but that Bt corn does have a toxic effect on rusty crayfish during long-term exposure. PMID:25001246

  16. Arsenic uptake and depuration by red crayfish, Procambarus clarkii, exposed to various concentrations of monosodium methanearsonate (MSMA) herbicide

    SciTech Connect

    Naqvi, S.M.; Flagge, C.T.; Hawkins, R.L. )

    1990-07-01

    Like many other heavy metals, arsenic is known to accumulate in the tissues of aquatic organisms including crayfish. One of the earliest reports on red crayfish, Procambarus clarkii, reported the bioaccumulation factor (BF) ratios for radioactive sodium methanearsonate to range from 80-480. Other heavy metals, i.e., Cr, Cd, Pb and Hg have also been reported to accumulate experimentally in P. clarkii tissues. This study was conducted to evaluate in the laboratory the bio-accumulative potential of As by the American red crayfish, Procambarus clarkii, which is abundant in Louisiana; and also to assess the level of arsenic present in the tissues of fieldcollected individuals. Total revenues from the sales of this crayfish exceeds $143 million annually.

  17. Copper, cadmium, and nickel accumulation in crayfish populations near copper-nickel smelters at Sudbury, Ontario, Canada

    SciTech Connect

    Bagatto, G.; Aikhan, M.A.

    1987-03-01

    The Sudbury basin, an elliptical 646 square mile depression containing a number of freshwater reservoirs, has been subjected to extreme ecological disturbances from logging, mining and smelting activities. The purpose of the present study was to compare tissue concentration of copper, cadmium and nickel in freshwater crayfish at selected distances of the habitat from the emission source. Various tissue concentrations in crayfish from the sites were also examined to determine if particular body tissues were specific sites for metal accumulation.

  18. Juvenile Sex Offenders.

    PubMed

    Ryan, Eileen P; Otonichar, Joseph M

    2016-07-01

    Sexual offending by juveniles accounts for a sizable percentage of sexual offenses, especially against young children. In this article, recent research on female juvenile sex offenders (JSOs), risk factors for offending in juveniles, treatment, and the ways in which these youth may differ from general delinquents will be reviewed. Most JSOs do not go on to develop paraphilic disorders or to commit sex offenses during adulthood, and as a group, they are more similar to nonsexual offending juvenile delinquents than to adult sex offenders. Recent research has elucidated some differences between youth who commit sex offenses and general delinquents in the areas of atypical sexual interests, the use of pornography, and early sexual victimization during childhood. PMID:27222141

  19. Influence of Coarse Woody Debris and Particulate Organic Matter on Density and Biomass of the Crayfish Procambarus versutus

    NASA Astrophysics Data System (ADS)

    Mitchell, R. M.; Feminella, J. W.

    2005-05-01

    We estimated the density and growth of several populations of the crayfish Procambarus versutus (Cambaridae) in small sandy-bottom streams within the Southeastern Coastal Plain, at Fort Benning, Georgia. Study streams had varying levels of coarse woody debris (CWD, 4-13% of stream bottom surface) and benthic particulate organic matter (>2cm, BPOM, 1-5% of substrate). Limited work has been done to assess if CWD or BPOM, primary habitat and food resources, respectively, influence crayfish population dynamics, despite the high bioenergetic importance of crayfish in many streams. Mean monthly densities were highest in the stream with the highest %CWD and %BPOM compared with other streams; however, monthly biomass was not always highest in the high-density, high-%CWD/BPOM stream. Instead, the intermediate-%CWD stream typically had the highest crayfish biomass. This disparity may be explained by differential food quality among streams and omnivory. Benthic macroinvertebrate density and biomass both were highest in the intermediate-%CWD/POM stream, and higher macroinvertebrate biomass may have compensated for lower BPOM abundance in crayfish diets, and thus provide a better food resource for P. versutus. We are currently using stable isotope data from crayfish and potential food resources among streams to test this hypothesis.

  20. Hardy exotics species in temperate zone: can “warm water” crayfish invaders establish regardless of low temperatures?

    PubMed Central

    Veselý, Lukáš; Buřič, Miloš; Kouba, Antonín

    2015-01-01

    The spreading of new crayfish species poses a serious risk for freshwater ecosystems; because they are omnivores they influence more than one level in the trophic chain and they represent a significant part of the benthic biomass. Both the environmental change through global warming and the expansion of the pet trade increase the possibilities of their spreading. We investigated the potential of four “warm water” highly invasive crayfish species to overwinter in the temperate zone, so as to predict whether these species pose a risk for European freshwaters. We used 15 specimens of each of the following species: the red swamp crayfish (Procambarus clarkii), the marbled crayfish (Procambarus fallax f. virginalis), the yabby (Cherax destructor), and the redclaw (Cherax quadricarinatus). Specimens were acclimatized and kept for 6.5 months at temperatures simulating the winter temperature regime of European temperate zone lentic ecosystems. We conclude that the red swamp crayfish, marbled crayfish and yabby have the ability to withstand low winter temperatures relevant for lentic habitats in the European temperate zone, making them a serious invasive threat to freshwater ecosystems. PMID:26572317

  1. Genetics Home Reference: juvenile polyposis syndrome

    MedlinePlus

    ... In the third type, known as juvenile polyposis coli, affected individuals develop polyps only in their colon. People with generalized juvenile polyposis and juvenile polyposis coli typically develop polyps during childhood. Most juvenile polyps ...

  2. White spot syndrome virus enters crayfish hematopoietic tissue cells via clathrin-mediated endocytosis.

    PubMed

    Huang, Jiajun; Li, Fang; Wu, Junjun; Yang, Feng

    2015-12-01

    White spot syndrome virus (WSSV) is a major pathogen of aquacultured shrimp. However, the mechanism of its entry remains poorly understood. In this study, by analyzing the internalization of WSSV using crayfish hematopoietic tissue (HPT) cells, we showed that WSSV virions were engulfed by cell membrane invaginations sharing the features of clathrin-coated pits and then internalized into coated cytoplasmic vesicles. Further investigation indicated that WSSV internalization was significantly inhibited by chlorpromazine (CPZ) but not genistein. The internalized virions were colocalized with endogenous clathrin as well as transferrin which undergoes clathrin-dependent uptake. Preventing endosome acidification by ammonium chloride (NH4Cl) or chloroquine (CQ) dramatically reduced WSSV entry as well. Moreover, disturbance of dynamin activity or depletion of membrane cholesterol also blocked WSSV uptake. These data indicate that WSSV enters crayfish HPT cells via clathrin-mediated endocytosis in a pH-dependent manner, and membrane cholesterol as well as dynamin is critical for efficient viral entry.

  3. The complete mitogenome of the Australian land crayfish Engaeus lyelli (Clark 1936) (Crustacea: Decapoda: Parastacidae).

    PubMed

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

    2016-01-01

    The complete mitochondrial genome of the enigmatic freshwater crayfish Engaeus lyelli was sequenced using the MiSeq Personal Sequencer (Illumina, San Diego, CA). The mitogenome has 16,027 bp consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 23 transfer RNAs, and a non-coding AT-rich region. The base composition of E. lyelli is 29.01% for T, 27.13% for C, 31.43% for A, and 12.44% for G, with an AT bias of 60.44%. The species has the distinctive gene order characteristic of parastacid crayfish with the exception of some minor rearrangements involving the tRNA genes.

  4. West Virginia crayfishes (Decapoda: Cambaridae): observations on distribution, natural history, and conservation

    USGS Publications Warehouse

    Loughman, Zachary J.; Simon, Thomas P.; Welsh, Stuart A.

    2009-01-01

    West Virginia's crayfishes have received moderate attention since publication of Jezerinac et al.'s (1995) monograph of the state fauna. Survey efforts were initiated over the summers of 2006 and 2007 to gather voucher material for the Indiana Biological Survey's Crustacean Collection. These collections have provided new information regarding the distribution, natural history, life history, taxonomy, and conservation status of Cambarus (Cambarus) carinirostris, C. (C.) bartonii cavatus, C. (C.) sciotensis, C. (Hiaticambarus) chasmodactylus, C. (H.) elkensis, C. (H.) longulus, C. (Jugicambarus) dubius, C. (Puncticambarus) robustus, Orconectes (Procericambarus) cristavarius, and O. (P.) rusticus. Orconectes (Faxonius) limosus has apparently been extirpated from West Virginia and should be removed from the state's list of extant crayfishes.

  5. West Virginia crayfishes (Decapoda: Cambaridae): observations on distribution, natural history, and conservation

    USGS Publications Warehouse

    Loughman, Zachary J.; Simon, Thomas P.; Welsh, Stuart A.

    2015-01-01

    West Virginia's crayfishes have received moderate attention since publication of Jezerinac et al.'s (1995) monograph of the state fauna. Survey efforts were initiated over the summers of 2006 and 2007 to gather voucher material for the Indiana Biological Survey's Crustacean Collection. These collections have provided new information regarding the distribution, natural history, life history, taxonomy, and conservation status of Cambarus (Cambarus) carinirostris, C. (C.) bartonii cavatus, C. (C.) sciotensis, C. (Hiaticambarus) chasmodactylus, C. (H.) elkensis, C. (H.) longulus, C. (Jugicambarus) dubius, C. (Puncticambarus) robustus, Orconectes (Procericambarus) cristavarius, and O. (P.) rusticus. Orconectes (Faxonius) limosus has apparently been extirpated from West Virginia and should be removed from the state's list of extant crayfishes.

  6. De Novo assembly and annotation of the freshwater crayfish Astacus astacus transcriptome.

    PubMed

    Theissinger, Kathrin; Falckenhayn, Cassandra; Blande, Daniel; Toljamo, Anna; Gutekunst, Julian; Makkonen, Jenny; Jussila, Japo; Lyko, Frank; Schrimpf, Anne; Schulz, Ralf; Kokko, Harri

    2016-08-01

    We generated RNA-seq data to assemble the transcriptome of the noble crayfish (Astacus astacus) from four combined tissues (abdominal muscle, hepatopancreas, ovaries, green glands). A total of 194 million read pairs with a length of 100 bp were generated. The transcriptome was assembled de novo using Trinity software, producing 158,649 non-redundant transcripts. Lowly expressed transcripts were filtered out leaving 45,415 transcripts of which 14,559 were found to contain open reading frames with predicted gene function. The Transrate software revealed that 91% of the total reads were realigned to the assembly. Furthermore, BUSCO analysis indicated that our assembly is 64% complete. A total of 13,770 transcripts were assigned at least one GO term. This first de novo transcriptome assembly is an important foundation for future genomic research on the noble crayfish and adds to the general knowledge and further characterization of transcriptomes of non-model organisms. PMID:26988698

  7. Effects of historical lead-zinc mining on riffle-dwelling benthic fish and crayfish in the Big River of southeastern Missouri, USA.

    PubMed

    Allert, A L; DiStefano, R J; Fairchild, J F; Schmitt, C J; McKee, M J; Girondo, J A; Brumbaugh, W G; May, T W

    2013-04-01

    The Big River (BGR) drains much of the Old Lead Belt mining district (OLB) in southeastern Missouri, USA, which was historically among the largest producers of lead-zinc (Pb-Zn) ore in the world. We sampled benthic fish and crayfish in riffle habitats at eight sites in the BGR and conducted 56-day in situ exposures to the woodland crayfish (Orconectes hylas) and golden crayfish (Orconectes luteus) in cages at four sites affected to differing degrees by mining. Densities of fish and crayfish, physical habitat and water quality, and the survival and growth of caged crayfish were examined at sites with no known upstream mining activities (i.e., reference sites) and at sites downstream of mining areas (i.e., mining and downstream sites). Lead, zinc, and cadmium were analyzed in surface and pore water, sediment, detritus, fish, crayfish, and other benthic macro-invertebrates. Metals concentrations in all materials analyzed were greater at mining and downstream sites than at reference sites. Ten species of fish and four species of crayfish were collected. Fish and crayfish densities were significantly greater at reference than mining or downstream sites, and densities were greater at downstream than mining sites. Survival of caged crayfish was significantly lower at mining sites than reference sites; downstream sites were not tested. Chronic toxic-unit scores and sediment probable effects quotients indicated significant risk of toxicity to fish and crayfish, and metals concentrations in crayfish were sufficiently high to represent a risk to wildlife at mining and downstream sites. Collectively, the results provided direct evidence that metals associated with historical mining activities in the OLB continue to affect aquatic life in the BGR.

  8. Effects of historical lead–zinc mining on riffle-dwelling benthic fish and crayfish in the Big River of southeastern Missouri, USA

    USGS Publications Warehouse

    Allert, A.L.; DiStefano, R.J.; Fairchild, J.F.; Schmitt, C.J.; McKee, M.J.; Girondo, J.A.; Brumbaugh, W.G.; May, T.W.

    2013-01-01

    The Big River (BGR) drains much of the Old Lead Belt mining district (OLB) in southeastern Missouri, USA, which was historically among the largest producers of lead–zinc (Pb–Zn) ore in the world. We sampled benthic fish and crayfish in riffle habitats at eight sites in the BGR and conducted 56-day in situ exposures to the woodland crayfish (Orconectes hylas) and golden crayfish (Orconectes luteus) in cages at four sites affected to differing degrees by mining. Densities of fish and crayfish, physical habitat and water quality, and the survival and growth of caged crayfish were examined at sites with no known upstream mining activities (i.e., reference sites) and at sites downstream of mining areas (i.e., mining and downstream sites). Lead, zinc, and cadmium were analyzed in surface and pore water, sediment, detritus, fish, crayfish, and other benthic macro-invertebrates. Metals concentrations in all materials analyzed were greater at mining and downstream sites than at reference sites. Ten species of fish and four species of crayfish were collected. Fish and crayfish densities were significantly greater at reference than mining or downstream sites, and densities were greater at downstream than mining sites. Survival of caged crayfish was significantly lower at mining sites than reference sites; downstream sites were not tested. Chronic toxic-unit scores and sediment probable effects quotients indicated significant risk of toxicity to fish and crayfish, and metals concentrations in crayfish were sufficiently high to represent a risk to wildlife at mining and downstream sites. Collectively, the results provided direct evidence that metals associated with historical mining activities in the OLB continue to affect aquatic life in the BGR.

  9. Concentrations of aluminum in gut tissue of crayfish (Procambarus clarkii), purged in sodium chloride

    SciTech Connect

    Madigosky, S.R.; Alvarez-Hernandez, X.; Glass, J.

    1992-10-01

    Recent concern over the release of Al in the environment has prompted researchers and health officials to assess its effects on biological systems. Aluminum, despite being the most abundant metal in earth`s lithosphere, is normally complexed in soil and is therefore unavailable for biological assimilation. The recent advent of acid rain, however, has prompted Al release due to mobilization from surrounding sediments into the environment. This is of particular concern in aquatic environments because organisms in aquatic food chains can access and concentrate sublethal levels of Al in their tissues relatively quickly. The ingestion of affected organisms by humans may therefore pose a potential health risk. One such organism, is known to concentrate metals in a variety of tissues. In northern Louisiana, many people trap or fish for crayfish in lowland areas which lie adjacent to highways and secondary roadways. Water, soil, and crayfish from these areas are known to contain high levels of Al. Some tissues known to concentrate Al (muscle, hepatopancreas and intestine tissue and contents) are those which humans commonly consume. The ingestion of these tissues may therefore expose humans to elevated Al levels. Many people who eat crayfish often purge them in dilute concentrations (1-2%) of NaCl to rid them of contaminants and make them more palatable. We are aware of no literature which corroborates the claim that purging removes contaminating metals. The objectives of this study were to (1) document the amount of Al found in water, soil, and gut tissue of crayfish (P. clarkii) collected from a roadside wetland site; (2) determine the affect of NaCl purging on the release of Al in P. clarkii and (3) assess the differences in Al levels found between stomach tissue, stomach tissue contents, intestine tissue, and intestine contents in P. clarkii. 12 refs., 3 figs., 1 tab.

  10. Cloning and functional analysis of glutathione peroxidase gene in red swamp crayfish Procambarus clarkii.

    PubMed

    Xia, Xiao-Fei; Zheng, Jin-Jing; Shao, Guang-Ming; Wang, Jia-Lin; Liu, Xu-Sheng; Wang, Yu-Feng

    2013-06-01

    Glutathione peroxidases (GPxs) are key enzymes in the antioxidant defense systems of living organisms, including crustaceans. The red swamp crayfish Procambarus clarkii is the most commonly farmed freshwater crayfish in Chinese inland nowadays due to its commercial value. However, high stocking density has resulted in adverse effects in growth performance and health. To investigate the function of GPxs in immune defense of the crayfish, we cloned and characterized a full length GPx (PcGPx) from P. clarkii by a reverse-transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The 931 bp PcGPx cDNA contains a 38 bp 5'-untranslated region (UTR), a 519 bp coding sequence (CDS) and a 375 bp 3'-UTR with a selenocysteine insertion sequence (SECIS). The PcGPx was predicted to encode 172 amino acids, and its putative molecular mass was 20.9 kDa with a pI of 4.37. A selenocysteine (Sec) encoded by the unusual stop codon, TGA, was in the protein coding region. Phylogenetic analysis showed that PcGPx clustered with the GPxs from the penaeid shrimp Metapenaeus ensis and Caenorhabditis elegans, sharing much higher similarity with vertebrate GPx1 and GPx2 than with GPx3 and GPx5. Quantitative RT-PCR revealed that PcGPx was extremely highly expressed in ovary and early embryos. In addition, the levels of PcGPx mRNA and reactive oxygen species (ROS) significantly increased after challenge with gram-negative Vibrio harveyi, gram-positive Staphyloccocus aureus or white spot syndrome virus (WSSV). These results suggest that PcGPx may play important roles not only in immune defense, but also in oogenesis in the crayfish.

  11. The Effects of Limb Coordination on the Swimming Efficiency of Crayfish

    NASA Astrophysics Data System (ADS)

    Guy, Robert; Zhang, Jiawei; Zhang, Qinghai; Lewis, Timothy

    2012-11-01

    Limbs of crayfish, called swimmerets, move rhythmically in a metachronal wave that progresses from back to front during forward swimming. Neighboring swimmerets maintain phase-lags of about 25% over a wide range of frequencies. This ``phase constancy'' suggests that there may be mechanical advantages to this stroke pattern. We use the immersed-boundary method to simulate the coupled mechanics of the swimmerets and the surrounding fluid in order to explore how stroke patterns affect swimming efficiency.

  12. River bank burrowing by invasive crayfish: Spatial distribution, biophysical controls and biogeomorphic significance.

    PubMed

    Faller, Matej; Harvey, Gemma L; Henshaw, Alexander J; Bertoldi, Walter; Bruno, Maria Cristina; England, Judy

    2016-11-01

    Invasive species generate significant global environmental and economic costs and represent a particularly potent threat to freshwater systems. The biogeomorphic impacts of invasive aquatic and riparian species on river processes and landforms remain largely unquantified, but have the potential to generate significant sediment management issues within invaded catchments. Several species of invasive (non-native) crayfish are known to burrow into river banks and visual evidence of river bank damage is generating public concern and media attention. Despite this, there is a paucity of understanding of burrow distribution, biophysical controls and the potential significance of this problem beyond a small number of local studies at heavily impacted sites. This paper presents the first multi-catchment analysis of this phenomenon, combining existing data on biophysical river properties and invasive crayfish observations with purpose-designed field surveys across 103 river reaches to derive key trends. Crayfish burrows were observed on the majority of reaches, but burrowing tended to be patchy in spatial distribution, concentrated in a small proportion (<10%) of the length of rivers surveyed. Burrow distribution was better explained by local bank biophysical properties than by reach-scale properties, and burrowed banks were more likely to be characterised by cohesive bank material, steeper bank profiles with large areas of bare bank face, often on outer bend locations. Burrow excavation alone has delivered a considerable amount of sediment to invaded river systems in the surveyed sites (3tkm(-1) impacted bank) and this represents a minimum contribution and certainly an underestimate of the absolute yield (submerged burrows were not recorded). Furthermore, burrowing was associated with bank profiles that were either actively eroding or exposed to fluvial action and/or mass failure processes, providing the first quantitative evidence that invasive crayfish may cause or

  13. River bank burrowing by invasive crayfish: Spatial distribution, biophysical controls and biogeomorphic significance.

    PubMed

    Faller, Matej; Harvey, Gemma L; Henshaw, Alexander J; Bertoldi, Walter; Bruno, Maria Cristina; England, Judy

    2016-11-01

    Invasive species generate significant global environmental and economic costs and represent a particularly potent threat to freshwater systems. The biogeomorphic impacts of invasive aquatic and riparian species on river processes and landforms remain largely unquantified, but have the potential to generate significant sediment management issues within invaded catchments. Several species of invasive (non-native) crayfish are known to burrow into river banks and visual evidence of river bank damage is generating public concern and media attention. Despite this, there is a paucity of understanding of burrow distribution, biophysical controls and the potential significance of this problem beyond a small number of local studies at heavily impacted sites. This paper presents the first multi-catchment analysis of this phenomenon, combining existing data on biophysical river properties and invasive crayfish observations with purpose-designed field surveys across 103 river reaches to derive key trends. Crayfish burrows were observed on the majority of reaches, but burrowing tended to be patchy in spatial distribution, concentrated in a small proportion (<10%) of the length of rivers surveyed. Burrow distribution was better explained by local bank biophysical properties than by reach-scale properties, and burrowed banks were more likely to be characterised by cohesive bank material, steeper bank profiles with large areas of bare bank face, often on outer bend locations. Burrow excavation alone has delivered a considerable amount of sediment to invaded river systems in the surveyed sites (3tkm(-1) impacted bank) and this represents a minimum contribution and certainly an underestimate of the absolute yield (submerged burrows were not recorded). Furthermore, burrowing was associated with bank profiles that were either actively eroding or exposed to fluvial action and/or mass failure processes, providing the first quantitative evidence that invasive crayfish may cause or

  14. A fibrinogen-related protein identified from hepatopancreas of crayfish is a potential pattern recognition receptor.

    PubMed

    Chen, Qiming; Bai, Suhua; Dong, Chaohua

    2016-09-01

    Fibrinogen-related protein (FREP) family is a large group of proteins containing fibrinogen-like (FBG) domain and plays multiple physiological roles in animals. However, their immune functions in crayfish are not fully explored. In the present study, a novel fibrinogen-like protein (designated as PcFBN1) was identified and characterized from hepatopancreas of red swamp crayfish Procambarus clarkii. The cDNA sequence of PcFBN1 contains an open reading frame (ORF) of 1353 bp encoding a protein of 450 amino acids. Sequence and structural analysis indicated that PcFBN1 contains an FBG domain in C-terminal and a putative signal peptide of 19 amino acids in N-terminal. Semi-quantitative PCR revealed that the main expression of PcFBN1 was observed in hepatopancreas and hemocyte. Temporal expression analysis exhibited that PcFBN1 expression could be significantly induced by heat-killed Aeromonas hydrophila. Tissue distribution and temporal change of PcFBN1 suggested that PcFBN1 may be involved in immune responses of red swamp crayfish. Recombinant PcFBN1 protein binds and agglutinates both gram-negative bacteria Escherichia coli and gram-positive bacteria Micrococcus lysodeikticus. Moreover, binding and agglutination is Ca(2+) dependent. Further analysis indicated that PcFBN1 recognizes some acetyl group-containing substance LPS and PGN. RNAi experiment revealed that PcFBN1 is required for bacterial clearance and survival from A. hydrophila infection. Reduction of PcFBN1 expression significantly decreased the survival and enhanced the number of A. hydrophila in the hemolymph. These results indicated that PcFBN1 plays an important role in the innate immunity of red swamp crayfish as a potential pattern recognition receptor. PMID:27417229

  15. Crayfish impact desert river ecosystem function and litter-dwelling invertebrate communities through association with novel detrital resources.

    PubMed

    Moody, Eric K; Sabo, John L

    2013-01-01

    Shifts in plant species distributions due to global change are increasing the availability of novel resources in a variety of ecosystems worldwide. In semiarid riparian areas, hydric pioneer tree species are being replaced by drought-tolerant plant species as water availability decreases. Additionally, introduced omnivorous crayfish, which feed upon primary producers, allochthonous detritus, and benthic invertebrates, can impact communities at multiple levels through both direct and indirect effects mediated by drought-tolerant plants. We tested the impact of both virile crayfish (Orconectes virilis) and litter type on benthic invertebrates and the effect of crayfish on detrital resources across a gradient of riparian vegetation drought-tolerance using field cages with leaf litter bags in the San Pedro River in Southeastern Arizona. Virile crayfish increased breakdown rate of novel drought-tolerant saltcedar (Tamarix ramosissima), but did not impact breakdown of drought-tolerant seepwillow (Baccharis salicifolia) or hydric Fremont cottonwood (Populus fremontii) and Gooding's willow (Salix goodingii). Effects on invertebrate diversity were observed at the litter bag scale, but no effects were found at the cage scale. Crayfish decreased alpha diversity of colonizing macroinvertebrates, but did not affect beta diversity. In contrast, the drought-tolerant litter treatment decreased beta diversity relative to hydric litter. As drought-tolerant species become more abundant in riparian zones, their litter will become a larger component of the organic matter budget of desert streams which may serve to homogenize the litter-dwelling community and support elevated populations of virile crayfish. Through impacts at multiple trophic levels, crayfish have a significant effect on desert stream ecosystems.

  16. Crayfish Impact Desert River Ecosystem Function and Litter-Dwelling Invertebrate Communities through Association with Novel Detrital Resources

    PubMed Central

    Moody, Eric K.; Sabo, John L.

    2013-01-01

    Shifts in plant species distributions due to global change are increasing the availability of novel resources in a variety of ecosystems worldwide. In semiarid riparian areas, hydric pioneer tree species are being replaced by drought-tolerant plant species as water availability decreases. Additionally, introduced omnivorous crayfish, which feed upon primary producers, allochthonous detritus, and benthic invertebrates, can impact communities at multiple levels through both direct and indirect effects mediated by drought-tolerant plants. We tested the impact of both virile crayfish (Orconectes virilis) and litter type on benthic invertebrates and the effect of crayfish on detrital resources across a gradient of riparian vegetation drought-tolerance using field cages with leaf litter bags in the San Pedro River in Southeastern Arizona. Virile crayfish increased breakdown rate of novel drought-tolerant saltcedar (Tamarix ramosissima), but did not impact breakdown of drought-tolerant seepwillow (Baccharis salicifolia) or hydric Fremont cottonwood (Populus fremontii) and Gooding's willow (Salix goodingii). Effects on invertebrate diversity were observed at the litter bag scale, but no effects were found at the cage scale. Crayfish decreased alpha diversity of colonizing macroinvertebrates, but did not affect beta diversity. In contrast, the drought-tolerant litter treatment decreased beta diversity relative to hydric litter. As drought-tolerant species become more abundant in riparian zones, their litter will become a larger component of the organic matter budget of desert streams which may serve to homogenize the litter-dwelling community and support elevated populations of virile crayfish. Through impacts at multiple trophic levels, crayfish have a significant effect on desert stream ecosystems. PMID:23667600

  17. Tachykinin-related peptide and GABA-mediated presynaptic inhibition of crayfish photoreceptors.

    PubMed

    Glantz, R M; Miller, C S; Nässel, D R

    2000-03-01

    Off-axis illumination elicits lateral inhibition at the primary visual synapse in crustacea and insects. The evidence suggests that the inhibitory action is presynaptic (i.e., on the photoreceptor terminal) and that the amacrine neurons of the lamina ganglionaris (the first synaptic layer) may be part of the inhibitory pathway. The neurotransmitters and the synaptic mechanisms are unknown. We show by immunocytochemistry that GABA and a tachykinin-related peptide (TRP) are localized in the amacrine neurons of the crayfish lamina ganglionaris. Indirect evidence suggests that GABA and TRP may be colocalized in these neurons. The extensive processes of the amacrine neurons occupy lamina layers containing the terminals of photoreceptors. Application of exogenous GABA and TRP to photoreceptor terminals produces a short-latency, dose-dependent hyperpolarization with a decay time constant on the order of a few seconds. TRP also exhibits actions that evolve over several minutes. These include a reduction of the receptor potential (and the light-elicited current) by approximately 40% and potentiation of the action of GABA by approximately 100%. The mechanisms of TRP action in crayfish are not known, but a plausible pathway is a TRP-dependent elevation of intracellular Ca(2+) that reduces photoreceptor sensitivity in arthropods. Although the mechanisms are not established, the results indicate that in crayfish photoreceptors TRP displays actions on two time scales and can exert profound modulatory control over cell function.

  18. C-type lectin from red swamp crayfish Procambarus clarkii participates in cellular immune response.

    PubMed

    Zhang, Xiao-Wen; Wang, Xian-Wei; Sun, Chen; Zhao, Xiao-Fan; Wang, Jin-Xing

    2011-03-01

    Lectins are potential immune recognition proteins. In this study, a novel C-type lectin (Pc-Lec1) is reported in freshwater crayfish Procambarus clarkii. Pc-Lec1 encodes a protein of 163 amino acids with a putative signal peptide and a single carbohydrate recognition domain. It was constitutively expressed in various tissues of a normal crayfish, especially in the hepatopancreas and gills. Expressions of Pc-Lec1 were up-regulated in the hepatopancreas and gills of crayfish challenged with Vibrio anguillarum, Staphylococcus aureus, or the white spot syndrome virus. Recombinant mature Pc-Lec1 bound bacteria and polysaccharides (peptidoglycan, lipoteichoic acid, and lipopolysaccharide) but did not agglutinate bacteria. Pc-Lec1 enhanced hemocyte encapsulation of the sepharose beads in vitro, and the blocking of beads by a polyclonal antibody inhibited encapsulation. Pc-Lec1 promoted clearance of V. anguillarum in vivo. These results suggest that Pc-Lec1 is a pattern recognition receptor and participates in cellular immune response. Pc-Lec1 performs its function as an opsonin by enhancing the encapsulation or clearance of pathogenic bacteria.

  19. Comparative ultrastructure and carbohydrate composition of gastroliths from astacidae, cambaridae and parastacidae freshwater crayfish (crustacea, decapoda).

    PubMed

    Luquet, Gilles; Fernández, María S; Badou, Aïcha; 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

  20. Upstream dispersal of an invasive crayfish aided by a fish passage facility

    USGS Publications Warehouse

    Welsh, Stuart; Loughman, Zachary J.

    2015-01-01

    Fish passage facilities for reservoir dams have been used to restore habitat connectivity within riverine networks by allowing upstream passage for native species. These facilities may also support the spread of invasive species, an unintended consequence and potential downside of upstream passage structures. We documented dam passage of the invasive virile crayfish, Orconectes virilis (Hagen, 1870), at fish ladders designed for upstream passage of American eels, Anguilla rostrata (Lesueur, 1817), in the Shenandoah River drainage, USA. Ladder use and upstream passage of 11 virile crayfish occurred from 2007–2014 during periods of low river discharge (<30 m3s–1) and within a wide range of water temperatures from 9.0–28.6 °C. Virile crayfish that used the eel ladders were large adults with a mean carapace length and width of 48.0 mm and 24.1 mm, respectively. Our data demonstrated the use of species-specific fish ladders by a non-target non-native species, which has conservation and management implications for the spread of aquatic invasive species and upstream passage facilities. Specifically, managers should consider implementing long-term monitoring of fish passage facilities with emphasis on detection of invasive species, as well as methods to reduce or eliminate passage of invasive species. 

  1. Sensitivity of adult, embryonic, and larval crayfish Procambarus clarkii to copper

    SciTech Connect

    Rice, D.W. Jr.; Harrison, F.L.

    1982-11-01

    The copper sensitivity of adult, embryonic, and larval stages of the crayfish Procambarus clarkii was determined with flow-through bioassay methods. The P. clarkii adults, embryos, and larvae were exposed continuously to copper concentrations that ranged from those producing an immediate effect to those producing none. From the family of curves of cumulative mortality versus duration of exposure, median lethal times were determined and used to construct comparative toxicity curves. The 20-d (480-h) median lethal concentrations show the order of copper sensitivity of P. clarkii life-history stages: larvae (120 ..mu..g Cu/L) > adults (1300 ..mu..g Cu/L) > embryos (3700 ..mu..g Cu/L). In addition, comparisons in percent hatching were made between P. clarkii embryos exposed early and late during embryological development. Embryos exposed to copper concentrations as low as 250 ..mu..g Cu/L 600 h prior to hatching showed only 17% hatching, whereas embryos exposed to as high as 2840 ..mu..g Cu/L 250 h prior showed 100% hatching. Larvae exposed to copper as embryos were less sensitive than those exposed after hatching. Copper concentrations in adult crayfish tissues were analyzed. The remains of adult crayfish showed exposure-related increases in copper accumulation. The P. clarkii muscle, gill, liver, and kidney showed no dose-related increases in copper accumulation, though gills showed significant increases in copper accumulation at doses of 480 ..mu..g Cu/L and higher.

  2. Metals in crayfish from neutralized acidic and non-acidic lakes

    SciTech Connect

    Bagatto, G.; Alikhan, M.A.

    1987-09-01

    Large amounts of acid forming SO/sub 2/, as well as Cu, Ni and other metals are being continuously released into the environment by mining and smelting activities at Sudbury, Ontario, Canada. Consequently, a number of lakes in this region has become both acid and metal stressed. The addition of basic calcium compounds to acidic ponds and lakes has long been recognized as beneficial, as it contributes to increased fish production and water quality. In addition to increases in pH and alkalinity, such additions may reduce water-dissolved metal concentrations, change water transparency and bring about alterations in species diversity. Neutralization experiments have shown that an increase in water alkalinity and DOC may reduce the acute toxicity of Cu to fish. However, the influence of water quality on metal availability and accumulation has received scant attention. Earlier work showed that tissue metal concentrations in crayfish were related to the distance from the emission site. The purpose of the present study is to compare concentrations of six metals in freshwater crayfish from a neutralized acidic lake and a closely situated non-acidic lake. Various tissue concentrations in crayfish are also examined to determine specific tissue sites for these accumulations.

  3. Multiple drivers of decline in the global status of freshwater crayfish (Decapoda: Astacidea).

    PubMed

    Richman, Nadia I; Böhm, Monika; Adams, Susan B; Alvarez, Fernando; Bergey, Elizabeth A; Bunn, John J S; Burnham, Quinton; Cordeiro, Jay; Coughran, Jason; Crandall, Keith A; Dawkins, Kathryn L; DiStefano, Robert J; Doran, Niall E; Edsman, Lennart; Eversole, Arnold G; Füreder, Leopold; Furse, James M; Gherardi, Francesca; Hamr, Premek; Holdich, David M; Horwitz, Pierre; Johnston, Kerrylyn; Jones, Clive M; Jones, Julia P G; Jones, Robert L; Jones, Thomas G; Kawai, Tadashi; Lawler, Susan; López-Mejía, Marilu; Miller, Rebecca M; Pedraza-Lara, Carlos; Reynolds, Julian D; Richardson, Alastair M M; Schultz, Mark B; Schuster, Guenter A; Sibley, Peter J; Souty-Grosset, Catherine; Taylor, Christopher A; Thoma, Roger F; Walls, Jerry; Walsh, Todd S; Collen, Ben

    2015-02-19

    Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the world's 590 freshwater crayfish species using the IUCN Categories and Criteria and found 32% of all species are threatened with extinction. The level of extinction risk differed between families, with proportionally more threatened species in the Parastacidae and Astacidae than in the Cambaridae. Four described species were Extinct and 21% were assessed as Data Deficient. There was geographical variation in the dominant threats affecting the main centres of crayfish diversity. The majority of threatened US and Mexican species face threats associated with urban development, pollution, damming and water management. Conversely, the majority of Australian threatened species are affected by climate change, harvesting, agriculture and invasive species. Only a small proportion of crayfish are found within the boundaries of protected areas, suggesting that alternative means of long-term protection will be required. Our study highlights many of the significant challenges yet to come for freshwater biodiversity unless conservation planning shifts from a reactive to proactive approach.

  4. Multiple drivers of decline in the global status of freshwater crayfish (Decapoda: Astacidea).

    PubMed

    Richman, Nadia I; Böhm, Monika; Adams, Susan B; Alvarez, Fernando; Bergey, Elizabeth A; Bunn, John J S; Burnham, Quinton; Cordeiro, Jay; Coughran, Jason; Crandall, Keith A; Dawkins, Kathryn L; DiStefano, Robert J; Doran, Niall E; Edsman, Lennart; Eversole, Arnold G; Füreder, Leopold; Furse, James M; Gherardi, Francesca; Hamr, Premek; Holdich, David M; Horwitz, Pierre; Johnston, Kerrylyn; Jones, Clive M; Jones, Julia P G; Jones, Robert L; Jones, Thomas G; Kawai, Tadashi; Lawler, Susan; López-Mejía, Marilu; Miller, Rebecca M; Pedraza-Lara, Carlos; Reynolds, Julian D; Richardson, Alastair M M; Schultz, Mark B; Schuster, Guenter A; Sibley, Peter J; Souty-Grosset, Catherine; Taylor, Christopher A; Thoma, Roger F; Walls, Jerry; Walsh, Todd S; Collen, Ben

    2015-02-19

    Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the world's 590 freshwater crayfish species using the IUCN Categories and Criteria and found 32% of all species are threatened with extinction. The level of extinction risk differed between families, with proportionally more threatened species in the Parastacidae and Astacidae than in the Cambaridae. Four described species were Extinct and 21% were assessed as Data Deficient. There was geographical variation in the dominant threats affecting the main centres of crayfish diversity. The majority of threatened US and Mexican species face threats associated with urban development, pollution, damming and water management. Conversely, the majority of Australian threatened species are affected by climate change, harvesting, agriculture and invasive species. Only a small proportion of crayfish are found within the boundaries of protected areas, suggesting that alternative means of long-term protection will be required. Our study highlights many of the significant challenges yet to come for freshwater biodiversity unless conservation planning shifts from a reactive to proactive approach. PMID:25561679

  5. Cloning and molecular characterization of a putative voltage-gated sodium channel gene in the crayfish.

    PubMed

    Coskun, Cagil; Purali, Nuhan

    2016-06-01

    Voltage-gated sodium channel genes and associated proteins have been cloned and studied in many mammalian and invertebrate species. However, there is no data available about the sodium channel gene(s) in the crayfish, although the animal has frequently been used as a model to investigate various aspects of neural cellular and circuit function. In the present work, by using RNA extracts from crayfish abdominal ganglia samples, the complete open reading frame of a putative sodium channel gene has firstly been cloned and molecular properties of the associated peptide have been analyzed. The open reading frame of the gene has a length of 5793 bp that encodes for the synthesis of a peptide, with 1930 amino acids, that is 82% similar to the α-peptide of a sodium channel in a neighboring species, Cancer borealis. The transmembrane topology analysis of the crayfish peptide indicated a pattern of four folding domains with several transmembrane segments, as observed in other known voltage-gated sodium channels. Upon analysis of the obtained sequence, functional regions of the putative sodium channel responsible for the selectivity filter, inactivation gate, voltage sensor, and phosphorylation have been predicted. The expression level of the putative sodium channel gene, as defined by a qPCR method, was measured and found to be the highest in nervous tissue. PMID:27032955

  6. Chronic Alterations in Serotonin Function: Dynamic Neurochemical Properties in Agonistic Behavior of the Crayfish, Orconectes rusticus

    PubMed Central

    Panksepp, Jules B.; Huber, Robert

    2016-01-01

    The biogenic amine serotonin [5-hydroxytryptamine (5-HT)] has received considerable attention for its role in behavioral phenomena throughout a broad range of invertebrate and vertebrate taxa. Acute 5-HT infusion decreases the likelihood of crayfish to retreat from dominant opponents. The present study reports the biochemical and behavioral effects resulting from chronic treatment with 5-HT-modifying compounds delivered for up to 5 weeks via silastic tube implants. High performance liquid chromatography with electrochemical detection (HPLC-ED) confirmed that 5,7-dihydroxytryptamine (5,7-DHT) effectively reduced 5-HT in all central nervous system (CNS) areas, except brain, while a concurrent accumulation of the compound was observed in all tissues analyzed. Unexpectedly, two different rates of chronic 5-HT treatment did not increase levels of the amine in the CNS. Behaviorally, 5,7-DHT treated crayfish exhibited no significant differences in measures of aggression. Although treatment with 5-HT did not elevate 5-HT content in the CNS, infusion at a slow rate caused animals to escalate more quickly while 5-HT treatment at a faster rate resulted in slower escalation. 5,7-DHT is commonly used in behavioral pharmacology and the present findings suggest its biochemical properties should be more thoroughly examined. Moreover, the apparent presence of powerful compensatory mechanisms indicates our need to adopt an increasingly dynamic view of the serotonergic bases of behavior like crayfish aggression. PMID:11891663

  7. Social status-dependent modulation of LG-flip habituation in the crayfish.

    PubMed

    Araki, Makoto; Hasegawa, Takuya; Komatsuda, Shohei; Nagayama, Toshiki

    2013-02-15

    Strong stimuli applied to the tailfan of the crayfish Procambarus clarkii evoked lateral giant interneurone (LG)-mediated tailflips. When the sensory stimulus was applied repeatedly, the response of the LG habituated until it failed to give rise to a spike. We found that this LG-flip habituation was dependent on social status. With a short interstimulus interval of 5 s, the rate of habituation of the LG in both socially dominant and subordinate crayfish was lower than that in socially isolated animals. By contrast, with a long interstimulus interval of 60 s, the rate of habituation of subordinate animals was lower than that of both socially isolated and dominant animals. The excitability of the LGs following habituation was also dependent on social status. Following habituation, the spike response of LGs recovered within several minutes; however, they showed significant depression with a decrease in excitability. With a 5 or 60 s interstimulus interval, subordinate animals showed longer delays of depression compared with dominant animals. A decrease in the rate of habituation and a delay of depression in subordinate crayfish would be advantageous for maintaining an active escape response to evade repeated attacks of dominant animals and a reduced learning ability to adapt to social status.

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

    PubMed Central

    Luquet, Gilles; Fernández, María S.; Badou, Aïcha; 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

  9. Multiple drivers of decline in the global status of freshwater crayfish (Decapoda: Astacidea)

    PubMed Central

    Richman, Nadia I.; Böhm, Monika; Adams, Susan B.; Alvarez, Fernando; Bergey, Elizabeth A.; Bunn, John J. S.; Burnham, Quinton; Cordeiro, Jay; Coughran, Jason; Crandall, Keith A.; Dawkins, Kathryn L.; DiStefano, Robert J.; Doran, Niall E.; Edsman, Lennart; Eversole, Arnold G.; Füreder, Leopold; Furse, James M.; Gherardi, Francesca; Hamr, Premek; Holdich, David M.; Horwitz, Pierre; Johnston, Kerrylyn; Jones, Clive M.; Jones, Julia P. G.; Jones, Robert L.; Jones, Thomas G.; Kawai, Tadashi; Lawler, Susan; López-Mejía, Marilu; Miller, Rebecca M.; Pedraza-Lara, Carlos; Reynolds, Julian D.; Richardson, Alastair M. M.; Schultz, Mark B.; Schuster, Guenter A.; Sibley, Peter J.; Souty-Grosset, Catherine; Taylor, Christopher A.; Thoma, Roger F.; Walls, Jerry; Walsh, Todd S.; Collen, Ben

    2015-01-01

    Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the world's 590 freshwater crayfish species using the IUCN Categories and Criteria and found 32% of all species are threatened with extinction. The level of extinction risk differed between families, with proportionally more threatened species in the Parastacidae and Astacidae than in the Cambaridae. Four described species were Extinct and 21% were assessed as Data Deficient. There was geographical variation in the dominant threats affecting the main centres of crayfish diversity. The majority of threatened US and Mexican species face threats associated with urban development, pollution, damming and water management. Conversely, the majority of Australian threatened species are affected by climate change, harvesting, agriculture and invasive species. Only a small proportion of crayfish are found within the boundaries of protected areas, suggesting that alternative means of long-term protection will be required. Our study highlights many of the significant challenges yet to come for freshwater biodiversity unless conservation planning shifts from a reactive to proactive approach. PMID:25561679

  10. Do antennule and aesthetasc structure in the crayfish Orconectes virilis correlate with flow habitat?

    PubMed

    Mead, Kristina S

    2008-12-01

    The local flow environment affects the shape of waterborne chemical signals through a variety of physical mechanisms and at several scales. Since crayfish rely on these chemical signals to extract information about predators, prey, and mates, one might expect the chemical sensors (aesthetascs) on crayfish antennules to be physically tuned to the presentation of chemical cues by the flow environment. This hypothesis was tested by comparing length, diameter, and spacing of antennules and aesthetascs among geographically distinct populations of Orconectes virilis. Crayfish were collected from the Chagrin river, Hebron hatchery, and Burt lake. In addition, antennules were sampled from 43 museum populations representing 12 lake, 10 creek, and 21 river populations from multiple states and river drainages. Mean velocities from the collection sites were either measured directly or calculated from United States Geological Survey (USGS) historical data. Structural parameters were measured using Scion Image software on Scanning electron microscope micrographs, and analyses of variance were performed using StatView. Structural parameters of aesthetascs were found to vary with flow environment. Aesthetascs from lake populations were inserted at a larger angle, extended out farther from the supporting antennule relative to the width of the antennule, and were more widely spaced than aesthetascs from creek, hatchery, and river populations.

  11. Juvenile Sex Offenders.

    PubMed

    Ryan, Eileen P

    2016-01-01

    Public policy has tended to treat juvenile sex offenders (JSOs) as adult sex offenders in waiting, despite research that contradicts this notion. Although as a group, JSOs are more similar to general delinquents than to adult sex offenders, atypical sexual interests and sexual victimization during childhood may be a pathway for sexual offending that differentiates some JSOs from their nonsexually delinquent peers. Developmental considerations must be considered in risk assessment evaluations of these youth. This article reviews theories of sexual offending in youth, risk factors for juvenile offending and reoffending, psychopathology in JSOs, risk assessment, and treatment. PMID:26593121

  12. AFLP-PCR and RAPD-PCR evidences of the transmission of the pathogen Aphanomyces astaci (Oomycetes) to wild populations of European crayfish from the invasive crayfish species, Procambarus clarkii.

    PubMed

    Rezinciuc, Svetlana; Galindo, Javier; Montserrat, Joan; Diéguez-Uribeondo, Javier

    2014-07-01

    Aphanomyces astaci (Oomycetes) is responsible for the crayfish plague disease. This species is endemic of North America and five genotypes have been described using RAPD-PCR. The red swamp crayfish, Procambarus clarkii, is one of the most widely spread North American species and invasive in the world. However, no outbreaks on its specific genotype, i.e., genotype D, have ever been described in nature. We investigated three major series of crayfish plague outbreaks in indigenous crayfish populations of Austropotamobius pallipes, located in the areas of influence of P. clarkii. All samples collected tested positive for A. astaci using a rnDNA ITS-PCR test. We also performed an AFLP-PCR analysis on 19 isolates, and found that all isolates belong to genotype D. These isolates exhibited similar properties, i.e., adaptation to warm temperatures. We demonstrate, for the first time, the transmission of A. astaci genotype D to indigenous European populations of crayfish, and confirm that the properties of adaptation to warm water temperatures seem to be a specific character of genotype D. The results of this work emphasize once more the need of controlling invasive species and its trade, since they can carry harmful pathogens with specific adaptations or increased virulence in new environments.

  13. Cadmium and lead residues in field-collected red swamp crayfish (Procambarus clarkii) and uptake by alligator weed, Alternanthera philoxiroides

    SciTech Connect

    Naqvi, S.M.; Howell, R.D.; Sholas, M. . Dept. of Biological Sciences and Health Research Center)

    1993-01-01

    The whole-body residues of Cd and Pb in the tissues of Louisiana swamp crayfish (Procambarus clarkii) were determined by flame AAS technique. Test animals were collected from roadside ditches alongside major highways. The water and soil samples were also collected from the same sites. The mean Cd and Pb concentrations in crayfish tissues were 0.46 and 0.07, respectively. The levels of Cd and Pb in the water were 0.09 and 0.04; and in soil were 2.85 and 0.87 mg/1, respectively. The concentration of cadmium was 32 and Pb 12 times more than in the water. The bioaccumulation factors (BF) for Cd and Pb in crayfish tissues were 5.1 and 1.7, respectively. Alligator weed (Alternanthera philoxiroides) plants were exposed to 0.5 mg/1 Cd-chloride or Pb-nitrate solutions for 3 wk period, thrice. The mean Pb accumulation in roots was 1.31 mg/1, followed by stem (0.078 mg/1), but Cd only accumulated in root (0.83 mg/1). The BF for Pb and Cd in plant tissues were 14.8 and 16.6, respectively. The uptake of metals was time-dependent. These data suggest that although there is no biomagnification of Cd and Pb from alligator weed to crayfish, both metals readily accumulate in field-collected crayfish and laboratory-exposed alligator weed.

  14. Bioenergetics assessment of fish and crayfish consumption by river otter (Lontra canadensis): integrating prey availability, diet, and field metabolic rate

    USGS Publications Warehouse

    Dekar, Matthew P.; Magoulick, Daniel D.; Beringer, J.

    2010-01-01

    River otters (Lontra canadensis) are important predators in aquatic ecosystems, but few studies quantify their prey consumption. We trapped crayfish monthly as an index of availability and collected otter scat for diet analysis in the Ozark Mountains of northwestern Arkansas, USA. We measured otter daily energy expenditure (DEE) with the doubly labeled water method to develop a bioenergetics model for estimating monthly prey consumption. Meek's crayfish (Orconectes meeki) catch-per-unit-effort was positively related to stream temperature, indicating that crayfish were more available during warmer months. The percentage frequency of occurrence for crayfish in scat samples peaked at 85.0% in summer and was lowest (42.3%) in winter. In contrast, the percentage occurrence of fish was 13.3% in summer and 57.7% in winter. Estimates of DEE averaged 4738 kJ·day-1 for an otter with a body mass of 7842 g. Total biomass consumption ranged from 35 079 to 52 653 g·month-1 (wet mass), corresponding to a high proportion of fish and crayfish in the diet, respectively. Otter consumption represents a large fraction of prey production, indicating potentially strong effects of otters on trophic dynamics in stream ecosystems.

  15. Dear enemies and nasty neighbors in crayfish: effects of social status and sex on responses to familiar and unfamiliar conspecifics.

    PubMed

    Tierney, A J; Andrews, K; Happer, K R; White, M K M

    2013-10-01

    Our experiment examined the ability of crayfish (Procambarus clarkii) to discriminate between familiar and unfamiliar conspecifics of equivalent social status, and investigated whether this species displays dear enemy or nasty neighbor effects. Pairs of size and sex matched crayfish fought to establish social status and the resulting dominant and subordinate crayfish then participated in a choice phase in which they interacted with two conspecifics tethered in an arena. Both choice conspecifics had the same social status and sex, but one was familiar (the focal animal's previous opponent) and the other was novel. We found that subordinate focal animals of both sexes spent significantly more time in proximity to the unfamiliar choice animal, behavior inconsistent with the dear enemy and nasty neighbor hypotheses. In contrast, male and female dominant focals differed significantly: females spent more time close to and fighting with the familiar choice animal while male dominants responded equivalently to the two choice animals. Thus the response of crayfish toward familiar and unfamiliar conspecifics was complex and not explained by a single hypothesis. We suggest that, in addition to familiarity and unfamiliarity, the perceived threat-level of opponents influences the behavior of crayfish toward conspecifics.

  16. 'Leaves and eats shoots': direct terrestrial feeding can supplement invasive red swamp crayfish in times of need.

    PubMed

    Grey, Jonathan; Jackson, Michelle C

    2012-01-01

    We used stable isotope analyses to characterise the feeding dynamics of a population of red swamp crayfish in Lake Naivasha, Kenya, after the crash of submerged macrophytes and associated macroinvertebrates, and during a natural draw-down of the lake water level. We expected a heavy reliance upon a diet of detrital matter to sustain the population as a consequence, and indeed, for the majority of the crayfish population caught from the lake, we saw a concomitant shift in isotopic values reflecting a dietary change. However, we also caught individual crayfish that had occupied the footprints of hippopotamus and effectively extended their range beyond the lake up to 40 m into the riparian zone. Isotopic analysis confirmed limited nocturnal observations that these individuals were consuming living terrestrial plants in the vicinity of the footprints. These are the first empirical data to demonstrate direct use of terrestrial resources by an aquatic crayfish species and further highlight the traits that make red swamp crayfish such opportunistic and successful invaders. PMID:22880039

  17. In-depth comparative transcriptome analysis of intestines of red swamp crayfish, Procambarus clarkii, infected with WSSV.

    PubMed

    Du, Zhiqiang; Jin, Yanhui; Ren, Daming

    2016-01-01

    Crayfish has become one of the most important farmed aquatic species in China due to its excellent disease resistance against bacteria and viruses. However, the antiviral mechanism of crayfish is still not very clear. In the present study, many high-quality sequence reads from crayfish intestine were obtained using Illumina-based transcriptome sequencing. For the normal group (GN), 44,600,142 high-quality clean reads were randomly assembled to produce 125,394 contigs. For the WSSV-challenged group (GW), 47,790,746 high-quality clean reads were randomly assembled to produce 148,983 contigs. After GO annotation, 39,482 unigenes were annotated into three ontologies: biological processes, cellular components, and molecular functions. In addition, 15,959 unigenes were mapped to 25 different COG categories. Moreover, 7,000 DEGs were screened out after a comparative analysis between the GN and GW samples, which were mapped into 250 KEGG pathways. Among these pathways, 36 were obviously changed (P-values < 0.05) and 28 pathways were extremely significantly changed (P-values < 0.01). Finally, five key DEGs involved in the JAK-STAT signaling pathway were chosen for qRT-PCR. The results showed that these five DEGs were obviously up-regulated at 36 h post WSSV infection in crayfish intestine. These results provide new insight into crayfish antiviral immunity mechanisms. PMID:27283359

  18. 'Leaves and eats shoots': direct terrestrial feeding can supplement invasive red swamp crayfish in times of need.

    PubMed

    Grey, Jonathan; Jackson, Michelle C

    2012-01-01

    We used stable isotope analyses to characterise the feeding dynamics of a population of red swamp crayfish in Lake Naivasha, Kenya, after the crash of submerged macrophytes and associated macroinvertebrates, and during a natural draw-down of the lake water level. We expected a heavy reliance upon a diet of detrital matter to sustain the population as a consequence, and indeed, for the majority of the crayfish population caught from the lake, we saw a concomitant shift in isotopic values reflecting a dietary change. However, we also caught individual crayfish that had occupied the footprints of hippopotamus and effectively extended their range beyond the lake up to 40 m into the riparian zone. Isotopic analysis confirmed limited nocturnal observations that these individuals were consuming living terrestrial plants in the vicinity of the footprints. These are the first empirical data to demonstrate direct use of terrestrial resources by an aquatic crayfish species and further highlight the traits that make red swamp crayfish such opportunistic and successful invaders.

  19. In-depth comparative transcriptome analysis of intestines of red swamp crayfish, Procambarus clarkii, infected with WSSV

    PubMed Central

    Du, Zhiqiang; Jin, Yanhui; Ren, Daming

    2016-01-01

    Crayfish has become one of the most important farmed aquatic species in China due to its excellent disease resistance against bacteria and viruses. However, the antiviral mechanism of crayfish is still not very clear. In the present study, many high-quality sequence reads from crayfish intestine were obtained using Illumina-based transcriptome sequencing. For the normal group (GN), 44,600,142 high-quality clean reads were randomly assembled to produce 125,394 contigs. For the WSSV-challenged group (GW), 47,790,746 high-quality clean reads were randomly assembled to produce 148,983 contigs. After GO annotation, 39,482 unigenes were annotated into three ontologies: biological processes, cellular components, and molecular functions. In addition, 15,959 unigenes were mapped to 25 different COG categories. Moreover, 7,000 DEGs were screened out after a comparative analysis between the GN and GW samples, which were mapped into 250 KEGG pathways. Among these pathways, 36 were obviously changed (P-values < 0.05) and 28 pathways were extremely significantly changed (P-values < 0.01). Finally, five key DEGs involved in the JAK-STAT signaling pathway were chosen for qRT-PCR. The results showed that these five DEGs were obviously up-regulated at 36 h post WSSV infection in crayfish intestine. These results provide new insight into crayfish antiviral immunity mechanisms. PMID:27283359

  20. Juvenile Justice in Maryland.

    ERIC Educational Resources Information Center

    Vetter, Donald P.; Frederick, Charles

    This four part guide provides secondary students with information about Maryland laws, courts, and legal system. The first section examines the nature and causes of increasing involvement of youth in crime, and identifies those crimes most commonly committed by juveniles. A special section on shoplifting is included. Section II examines the nature…

  1. Juvenile nasopharyngeal angiofibroma.

    PubMed

    Vadivel, S P; Bosch, A; Jose, B

    1980-01-01

    Seven cases of juvenile nasopharyngeal angiofibroma were seen in the Division of Radiation Oncology of the Department of Human Oncology, University of Wisconsin Hospitals from 1961 to 1977. The method of treatments and the end results are discussed. The clinical manifestations and the biological nature of this tumor are analyzed in detail, along with treatment recommendations.

  2. Treating the Juvenile Offender

    ERIC Educational Resources Information Center

    Hoge, Robert D., Ed.; Guerra, Nancy G., Ed.; Boxer, Paul, Ed.

    2008-01-01

    This authoritative, highly readable reference and text is grounded in the latest knowledge on how antisocial and criminal behavior develops in youth and how it can effectively be treated. Contributors describe proven ways to reduce juvenile delinquency by targeting specific risk factors and strengthening young people's personal, family, and…

  3. System-Wide Significance of Predation on Juvenile Salmonids in the Columbia and Snake River Reservoirs : Annual Report of Research 1991.

    SciTech Connect

    Shively, R.S.

    1991-01-01

    We indexed consumption rates of northern squawfish (Ptychoch oregonensis) preying upon juvenile salmonids in four lower Snake River reservoirs. Stomach contents were also collected from smallmouth bass (Micropterus dolomieui), channel catfish (Ictaluris gunctatus), and walleye (Stizostedion vitreum). Northern squawfish digestive tracts were analyzed and the overall diet (% weight) was dominated by fish and crustaceans. Examination of stomach contents smallmouth bass showed that crustaceans (primarily crayfish) dominated their diets. Overall, the consumption rate of juvenile salmonids by smallmouth bass was low. The northern squawfish consumption index (CI) at Snake River locations ranged from zero at all mid-reservoir locations to 1.2 at Lower Granite forebay. In John Day Reservoir, CI values ranged from 0.5 to 1.9 in May and from 0.9 to 3.0 in July. Consumption index values were highest in forebay and tailrace areas, and were slightly higher in BRZs than in non-restricted zones.

  4. Long-Term Starvation and Posterior Feeding Effects on Biochemical and Physiological Responses of Midgut Gland of Cherax quadricarinatus Juveniles (Parastacidae).

    PubMed

    Sacristán, Hernán Javier; Ansaldo, Martín; Franco-Tadic, Luis Marcelo; Fernández Gimenez, Analía Verónica; López Greco, Laura Susana

    2016-01-01

    We investigated the effect of long-term starvation and posterior feeding on energetic reserves, oxidative stress, digestive enzymes, and histology of C. quadricarinatus midgut gland. The crayfish (6.27 g) were randomly assigned to one of three feeding protocols: continuous feeding throughout 80 day, continuous starvation until 80 day, and continuous starvation throughout 50 day and then feeding for the following 30 days. Juveniles from each protocol were weighed, and sacrificed at day 15, 30, 50 or 80. The lipids, glycogen, reduced glutathione (GSH), soluble protein, lipid peroxidation (TBARS), protein oxidation (PO), catalase (CAT), lipase and proteinase activities, and histology were measured on midgut gland. Starved crayfish had a lower hepatosomatic index, number of molts, specific growth rate, lipids, glycogen, and GSH levels than fed animals at all assay times. The starvation did not affect the soluble protein, TBARS, PO levels and CAT. In starved juveniles the lipase activity decreased as starvation time increased, whereas proteinase activity decreased only at day 80. The histological analysis of the starved animals showed several signs of structural alterations. After 30 days of feeding, the starved-feeding animals exhibited a striking recovery of hepatosomatic index, number of molts, lipids and glycogen, GSH, lipase activity and midgut gland structure. PMID:27018793

  5. Long-Term Starvation and Posterior Feeding Effects on Biochemical and Physiological Responses of Midgut Gland of Cherax quadricarinatus Juveniles (Parastacidae)

    PubMed Central

    Sacristán, Hernán Javier; Ansaldo, Martín; Franco-Tadic, Luis Marcelo; Fernández Gimenez, Analía Verónica; López Greco, Laura Susana

    2016-01-01

    We investigated the effect of long-term starvation and posterior feeding on energetic reserves, oxidative stress, digestive enzymes, and histology of C. quadricarinatus midgut gland. The crayfish (6.27 g) were randomly assigned to one of three feeding protocols: continuous feeding throughout 80 day, continuous starvation until 80 day, and continuous starvation throughout 50 day and then feeding for the following 30 days. Juveniles from each protocol were weighed, and sacrificed at day 15, 30, 50 or 80. The lipids, glycogen, reduced glutathione (GSH), soluble protein, lipid peroxidation (TBARS), protein oxidation (PO), catalase (CAT), lipase and proteinase activities, and histology were measured on midgut gland. Starved crayfish had a lower hepatosomatic index, number of molts, specific growth rate, lipids, glycogen, and GSH levels than fed animals at all assay times. The starvation did not affect the soluble protein, TBARS, PO levels and CAT. In starved juveniles the lipase activity decreased as starvation time increased, whereas proteinase activity decreased only at day 80. The histological analysis of the starved animals showed several signs of structural alterations. After 30 days of feeding, the starved-feeding animals exhibited a striking recovery of hepatosomatic index, number of molts, lipids and glycogen, GSH, lipase activity and midgut gland structure. PMID:27018793

  6. Long-Term Starvation and Posterior Feeding Effects on Biochemical and Physiological Responses of Midgut Gland of Cherax quadricarinatus Juveniles (Parastacidae).

    PubMed

    Sacristán, Hernán Javier; Ansaldo, Martín; Franco-Tadic, Luis Marcelo; Fernández Gimenez, Analía Verónica; López Greco, Laura Susana

    2016-01-01

    We investigated the effect of long-term starvation and posterior feeding on energetic reserves, oxidative stress, digestive enzymes, and histology of C. quadricarinatus midgut gland. The crayfish (6.27 g) were randomly assigned to one of three feeding protocols: continuous feeding throughout 80 day, continuous starvation until 80 day, and continuous starvation throughout 50 day and then feeding for the following 30 days. Juveniles from each protocol were weighed, and sacrificed at day 15, 30, 50 or 80. The lipids, glycogen, reduced glutathione (GSH), soluble protein, lipid peroxidation (TBARS), protein oxidation (PO), catalase (CAT), lipase and proteinase activities, and histology were measured on midgut gland. Starved crayfish had a lower hepatosomatic index, number of molts, specific growth rate, lipids, glycogen, and GSH levels than fed animals at all assay times. The starvation did not affect the soluble protein, TBARS, PO levels and CAT. In starved juveniles the lipase activity decreased as starvation time increased, whereas proteinase activity decreased only at day 80. The histological analysis of the starved animals showed several signs of structural alterations. After 30 days of feeding, the starved-feeding animals exhibited a striking recovery of hepatosomatic index, number of molts, lipids and glycogen, GSH, lipase activity and midgut gland structure.

  7. Transcriptome analysis and characterisation of gill-expressed carbonic anhydrase and other key osmoregulatory genes in freshwater crayfish Cherax quadricarinatus

    PubMed Central

    Ali, Muhammad Yousuf; Pavasovic, Ana; Mather, Peter B.; Prentis, Peter J.

    2015-01-01

    The pH and salinity balance mechanisms of crayfish are controlled by a set of transport-related genes. We identified a set of the genes from the gill transcriptome from a freshwater crayfish Cherax quadricarinatus using the Illumina NGS-sequencing technology. We identified and characterized carbonic anhydrase (CA) genes and some other key genes involved in systematic acid-base balance and osmotic/ionic regulation. We also examined expression patterns of some of these genes across different sublethal pH levels [1]. A total of 72,382,710 paired-end Illumina reads were assembled into 36,128 contigs with an average length of 800 bp. About 37% of the contigs received significant BLAST hits and 22% were assigned gene ontology terms. These data will assist in further physiological-genomic studies in crayfish. PMID:26543880

  8. Transcriptome analysis and characterisation of gill-expressed carbonic anhydrase and other key osmoregulatory genes in freshwater crayfish Cherax quadricarinatus.

    PubMed

    Ali, Muhammad Yousuf; Pavasovic, Ana; Mather, Peter B; Prentis, Peter J

    2015-12-01

    The pH and salinity balance mechanisms of crayfish are controlled by a set of transport-related genes. We identified a set of the genes from the gill transcriptome from a freshwater crayfish Cherax quadricarinatus using the Illumina NGS-sequencing technology. We identified and characterized carbonic anhydrase (CA) genes and some other key genes involved in systematic acid-base balance and osmotic/ionic regulation. We also examined expression patterns of some of these genes across different sublethal pH levels [1]. A total of 72,382,710 paired-end Illumina reads were assembled into 36,128 contigs with an average length of 800 bp. About 37% of the contigs received significant BLAST hits and 22% were assigned gene ontology terms. These data will assist in further physiological-genomic studies in crayfish. PMID:26543880

  9. Fluoride bioaccumulation and toxic effects on the survival and behavior of the endangered white-clawed crayfish Austropotamobius pallipes (Lereboullet).

    PubMed

    Aguirre-Sierra, Arantxa; Alonso, Alvaro; Camargo, Julio A

    2013-08-01

    Laboratory experiments were performed to examine the toxic effects of fluoride (F(-)) on the survival and behavior of white-clawed crayfish (Austropotamobius pallipes). Body fluoride contents (bioaccumulation) of test crayfish were also examined. No significant differences between male and female crayfish regarding mortality, escape (tail-flip) response, and fluoride bioaccumulation were detected. For mortality, 48-, 72-, 96-, 120-, 144-, 168-, and 192-h median lethal concentrations (LC50) were estimated to be 93.0, 55.3, 42.7, 36.5, 32.9, 30.6, and 28.9 mg F(-)/l, respectively. For the escape response, 48-, 72-, 96-, 120-, 144-, 168- and 192-h median effective concentrations (EC50) were estimated to be 18.4, 11.1, 8.6, 7.4, 6.7, 6.2 and 5.9 mg F(-)/l, respectively. Average food consumption in test crayfish tended to decrease with increasing water fluoride concentration with a 192-h lowest-observed effect concentration of 10.7 mg F(-)/l. These results indicate that the escape response was the most sensitive end point to fluoride toxicity followed by food consumption and mortality. Fluoride bioaccumulation in test crayfish increased with increasing water fluoride concentration and exposure time. The exoskeleton accumulated more fluoride than muscle. A comparison of the obtained results with previous data for other freshwater invertebrates shows that white-clawed crayfish are relatively tolerant to fluoride toxicity. We conclude that fluoride pollution in freshwater ecosystems should not be viewed as an important risk factor contributing to the catastrophic decrease of A. pallipes in many European countries. Our results indicate that fluoride bioaccumulation in A. pallipes might be used as a bioindicator of fluoride pollution in freshwater ecosystems where it is present.

  10. Prohibitin Interacts with envelope proteins of white spot syndrome virus and prevents infection in the red swamp crayfish, Procambarus clarkii.

    PubMed

    Lan, Jiang-Feng; Li, Xin-Cang; Sun, Jie-Jie; Gong, Jing; Wang, Xian-Wei; Shi, Xiu-Zhen; Shi, Li-Jie; Weng, Yu-Ding; Zhao, Xiao-Fan; Wang, Jin-Xing

    2013-12-01

    Prohibitins (PHBs) are ubiquitously expressed conserved proteins in eukaryotes that are associated with apoptosis, cancer formation, aging, stress responses, cell proliferation, and immune regulation. However, the function of PHBs in crustacean immunity remains largely unknown. In the present study, we identified a PHB in Procambarus clarkii red swamp crayfish, which was designated PcPHB1. PcPHB1 was widely distributed in several tissues, and its expression was significantly upregulated by white spot syndrome virus (WSSV) challenge at the mRNA level and the protein level. These observations prompted us to investigate the role of PcPHB1 in the crayfish antiviral response. Recombinant PcPHB1 (rPcPHB1) significantly reduced the amount of WSSV in crayfish and the mortality of WSSV-infected crayfish. The quantity of WSSV in PcPHB1 knockdown crayfish was increased compared with that in the controls. The effects of RNA silencing were rescued by rPcPHB1 reinjection. We further confirmed the interaction of PcPHB1 with the WSSV envelope proteins VP28, VP26, and VP24 using pulldown and far-Western overlay assays. Finally, we observed that the colloidal gold-labeled PcPHB1 was located on the outer surface of the WSSV, which suggests that PcPHB1 specifically binds to the envelope proteins of WSSV. VP28, VP26, and VP24 are structural envelope proteins and are essential for attachment and entry into crayfish cells. Therefore, PcPHB1 exerts its anti-WSSV effect by binding to VP28, VP26, and VP24, preventing viral infection. This study is the first report on the antiviral function of PHB in the innate immune system of crustaceans.

  11. Fluoride bioaccumulation and toxic effects on the survival and behavior of the endangered white-clawed crayfish Austropotamobius pallipes (Lereboullet).

    PubMed

    Aguirre-Sierra, Arantxa; Alonso, Alvaro; Camargo, Julio A

    2013-08-01

    Laboratory experiments were performed to examine the toxic effects of fluoride (F(-)) on the survival and behavior of white-clawed crayfish (Austropotamobius pallipes). Body fluoride contents (bioaccumulation) of test crayfish were also examined. No significant differences between male and female crayfish regarding mortality, escape (tail-flip) response, and fluoride bioaccumulation were detected. For mortality, 48-, 72-, 96-, 120-, 144-, 168-, and 192-h median lethal concentrations (LC50) were estimated to be 93.0, 55.3, 42.7, 36.5, 32.9, 30.6, and 28.9 mg F(-)/l, respectively. For the escape response, 48-, 72-, 96-, 120-, 144-, 168- and 192-h median effective concentrations (EC50) were estimated to be 18.4, 11.1, 8.6, 7.4, 6.7, 6.2 and 5.9 mg F(-)/l, respectively. Average food consumption in test crayfish tended to decrease with increasing water fluoride concentration with a 192-h lowest-observed effect concentration of 10.7 mg F(-)/l. These results indicate that the escape response was the most sensitive end point to fluoride toxicity followed by food consumption and mortality. Fluoride bioaccumulation in test crayfish increased with increasing water fluoride concentration and exposure time. The exoskeleton accumulated more fluoride than muscle. A comparison of the obtained results with previous data for other freshwater invertebrates shows that white-clawed crayfish are relatively tolerant to fluoride toxicity. We conclude that fluoride pollution in freshwater ecosystems should not be viewed as an important risk factor contributing to the catastrophic decrease of A. pallipes in many European countries. Our results indicate that fluoride bioaccumulation in A. pallipes might be used as a bioindicator of fluoride pollution in freshwater ecosystems where it is present. PMID:23532451

  12. Drug-sensitive reward in crayfish: an invertebrate model system for the study of SEEKING, reward, addiction, and withdrawal.

    PubMed

    Huber, Robert; Panksepp, Jules B; Nathaniel, Thomas; Alcaro, Antonio; Panksepp, Jaak

    2011-10-01

    In mammals, rewarding properties of drugs depend on their capacity to activate appetitive motivational states. With the underlying mechanisms strongly conserved in evolution, invertebrates have recently emerged as a powerful new model in addiction research. In crayfish natural reward has proven surprisingly sensitive to human drugs of abuse, opening an unlikely avenue of research into the basic biological mechanisms of drug addiction. In a series of studies we first examined the presence of natural reward systems in crayfish, then characterized its sensitivity to a wide range of human drugs of abuse. A conditioned place preference (CPP) paradigm was used to demonstrate that crayfish seek out those environments that had previously been paired with the psychostimulants cocaine and amphetamine, and the opioid morphine. The administration of amphetamine exerted its effects at a number of sites, including the stimulation of circuits for active exploratory behaviors (i.e., SEEKING). A further study examined morphine-induced reward, extinction and reinstatement in crayfish. Repeated intra-circulatory infusions of morphine served as a reward when paired with distinct visual or tactile cues. Morphine-induced CPP was extinguished after repeated saline injections. Following this extinction phase, morphine-experienced crayfish were once again challenged with the drug. The priming injections of morphine reinstated CPP at all tested doses, suggesting that morphine-induced CPP is unrelenting. In an exploration of drug-associated behavioral sensitization in crayfish we concurrently mapped measures of locomotion and rewarding properties of morphine. Single and repeated intra-circulatory infusions of morphine resulted in persistent locomotory sensitization, even 5 days following the infusion. Moreover, a single dose of morphine was sufficient to induce long-term behavioral sensitization. CPP for morphine and context-dependent cues could not be disrupted over a drug free period of 5

  13. Juvenile nasopharyngeal angiofibroma.

    PubMed

    Sellars, S L

    1980-12-13

    The juvenile nasopharyngeal angiofibroma, a locally invasive, non-metastasizing tumour of male adolescence, occurs sporadically throughout the world. Its histiogenesis remains uncertain and its management controversial. These facets of a troublesome and dangerous conditions are discussed and the experiences from handling 9 such tumours seen at Groote Schuur Hospital over a 4-year period (1976-1979) are presented. Surgical excision, using a wide field exposure and pre-operative systemic oestrogen medication, is recommended as the treatment of choice.

  14. Intracranial juvenile nasopharyngeal angiofibroma.

    PubMed

    Wylie, J P; Slevin, N J; Johnson, R J

    1998-01-01

    We report the case history of a 26-year-old man who was diagnosed with advanced juvenile nasopharyngeal angiofibroma with intracranial extension. The lesion was considered to be inoperable and the patient was treated with radical radiotherapy. Serial magnetic resonance imaging has shown continued tumour regression and he remains well after 3 years. The literature is reviewed and radiotherapy recommended as the modality of choice for these patients.

  15. Juvenile idiopathic arthritis.

    PubMed

    Gowdie, Peter J; Tse, Shirley M L

    2012-04-01

    Juvenile idiopathic arthritis (JIA) encompasses a complex group of disorders with arthritis as a common feature. This article provides the pediatrician with a review of the epidemiology, classification, clinical manifestations, and complications of JIA. It also provides an update on the current understanding of the cause of JIA and recent developments in management and a recent review of the long-term outcome in JIA.

  16. Electrophysiological Investigation of Different Methods of Anesthesia in Lobster and Crayfish

    PubMed Central

    Fregin, Torsten; Bickmeyer, Ulf

    2016-01-01

    Objectives In search for methods of anesthesia of crustaceans, an implanted electrode into lobster and crayfish CNS enabled us to monitor signal propagation in the nerve system of animals undergoing different protocols. Results Cooling (tap water 0°C, sea water -1,8°C) and anesthesia with MgCl2 (10%) were both discarded as anesthetic procedures because responses to external stimuli were still detectable under treatment. Contrarily, bubbling the aquarium water with CO2 can be considered a “partially successful” anesthesia, because signal propagation is inhibited but before that the animals show discomfort. The procedure of “electro-stunning” induces epileptic-form seizures in the crustacean CNS (lobster, crayfish), which overlay but do not mitigate the response to external stimuli. After several minutes the activity declines before the nervous system starts to recover. A feasible way to sacrifice lobsters is to slowly raise the water temperature (1°C min-1), as all electrical activities in the CNS cease at temperatures above ~30°C, whereas below this temperature the animals do not show signs of stress or escape behavior (e.g. tail flips) in the warming water. Conclusion CO2 is efficient to anaesthetize lobster and crayfish but due to low pH in water is stressful to the animals previous to anesthesia. Electrical stunning induces epileptiform seizures but paralyses the animals and leads to a reversible decline of nerve system activity after seizure. Electric stunning or slowly warming just before preparation may meet ethical expectations regarding anaesthesia and to sacrifice crustaceans. PMID:27642755

  17. Molecular cloning and expression of a GABA receptor subunit from the crayfish Procambarus clarkii.

    PubMed

    Jiménez-Vázquez, Eric N; Díaz-Velásquez, Clara E; Uribe, R M; Arias, Juan M; García, Ubaldo

    2016-02-01

    Molecular cloning has introduced an unexpected, large diversity of neurotransmitter hetero- oligomeric receptors. Extensive research on the molecular structure of the γ-aminobutyric acid receptor (GABAR) has been of great significance for understanding how the nervous system works in both vertebrates and invertebrates. However, only two examples of functional homo-oligomeric GABA-activated Cl(-) channels have been reported. In the vertebrate retina, the GABAρ1 subunit of various species forms homo-oligomeric receptors; in invertebrates, a cDNA encoding a functional GABA-activated Cl(-) channel has been isolated from a Drosophila melanogaster head cDNA library. When expressed in Xenopus laevis oocytes, these subunits function efficiently as a homo-oligomeric complex. To investigate the structure-function of GABA channels from the crayfish Procambarus clarkii, we cloned a subunit and expressed it in human embryonic kidney cells. Electrophysiological recordings show that this subunit forms a homo-oligomeric ionotropic GABAR that gates a bicuculline-insensitive Cl(-) current. The order of potency of the agonists was GABA > trans-4-amino-crotonic acid = cis-4-aminocrotonic acid > muscimol. These data support the notion that X-organ sinus gland neurons express at least two GABA subunits responsible for the formation of hetero-oligomeric and homo-oligomeric receptors. In addition, by in situ hybridization studies we demonstrate that most X-organ neurons from crayfish eyestalk express the isolated pcGABAA β subunit. This study increases the knowledge of the genetics of the crayfish, furthers the understanding of this important neurotransmitter receptor family, and provides insight into the evolution of these genes among vertebrates and invertebrates.

  18. A crayfish molar tooth protein with putative mineralized exoskeletal chitinous matrix properties.

    PubMed

    Tynyakov, Jenny; Bentov, Shmuel; Abehsera, Shai; Yehezkel, Galit; Roth, Ziv; Khalaila, Isam; Weil, Simy; Berman, Amir; Plaschkes, Inbar; Tom, Moshe; Aflalo, Eliahu D; Sagi, Amir

    2015-11-01

    Some crustaceans possess exoskeletons that are reinforced with calcium carbonate. In the crayfish Cherax quadricarinatus, the molar tooth, which is part of the mandibular exoskeleton, contains an unusual crystalline enamel-like apatite layer. As this layer resembles vertebrate enamel in composition and function, it offers an interesting example of convergent evolution. Unlike other parts of the crayfish exoskeleton, which is periodically shed and regenerated during the molt cycle, molar mineral deposition takes place during the pre-molt stage. The molar mineral composition transforms continuously from fluorapatite through amorphous calcium phosphate to amorphous calcium carbonate and is mounted on chitin. The process of crayfish molar formation is entirely extracellular and presumably controlled by proteins, lipids, polysaccharides, low-molecular weight molecules and calcium salts. We have identified a novel molar protein termed Cq-M15 from C. quadricarinatus and cloned its transcript from the molar-forming epithelium. Its transcript and differential expression were confirmed by a next-generation sequencing library. The predicted acidic pI of Cq-M15 suggests its possible involvement in mineral arrangement. Cq-M15 is expressed in several exoskeletal tissues at pre-molt and its silencing is lethal. Like other arthropod cuticular proteins, Cq-M15 possesses a chitin-binding Rebers-Riddiford domain, with a recombinant version of the protein found to bind chitin. Cq-M15 was also found to interact with calcium ions in a concentration-dependent manner. This latter property might make Cq-M15 useful for bone and dental regenerative efforts. We suggest that, in the molar tooth, this protein might be involved in calcium phosphate and/or carbonate precipitation. PMID:26385331

  19. β-Thymosins participate in antiviral immunity of red swamp crayfish (Procambarus clarkii).

    PubMed

    Shi, Xiu-Zhen; Shi, Li-Jie; Zhao, Yan-Ran; Zhao, Xiao-Fan; Wang, Jin-Xing

    2015-08-01

    β-Thymosins participate in numerous biological activities, including cell proliferation and differentiation, wound healing, and anti-inflammatory and antimicrobial activities. Many studies have investigated vertebrate β-thymosins, whereas few reports have focused on invertebrate β-thymosins. In this study, nine isoforms of β-thymosins (PcThy-1 to PcThy-8) were identified from the red swamp crayfish Procambarus clarkii. The isoforms contained different numbers of the thymosin β actin-binding motif. PcThy-1 contained one thymosin β actin-binding motif, whereas PcThy-8 contained eight motifs. Western blot analysis with anti-PcThy-4 antibody showed that three to six isoforms were present in one tissue, and PcThy-4, PcThy-5, PcThy-6, and PcThy-7 were the main isoforms in several tissues. Time course expression analysis of PcThys at the protein level showed that PcThy-4 was upregulated in hemocytes and gills after white spot syndrome virus (WSSV) challenge. PcThy-4, which contained four thymosin β actin-binding motifs, was selected for further research. Tissue distribution analysis by quantitative real-time PCR showed that PcThy-4 was present in tissues of the hemocytes, heart, hepatopancreas, gills, stomach, and intestine at the transcriptional level. Transcriptional expression profiles showed that PcThy-4 was upregulated after WSSV challenge. In vivo RNAi and protein injection assay results showed that PcThy-4 inhibited the replication of WSSV in crayfish and enhanced the survival rate after WSSV infection. Furthermore, PcThy-4 promoted hemocyte phagocytosis of WSSV. Overall, results suggested that PcThys protected crayfish from WSSV infection and played an important role in antiviral immune response. PMID:25892020

  20. Characterization of an immune deficiency homolog (IMD) in shrimp (Fenneropenaeus chinensis) and crayfish (Procambarus clarkii).

    PubMed

    Lan, Jiang-Feng; Zhou, Jing; Zhang, Xiao-Wen; Wang, Zong-Heng; Zhao, Xiao-Fan; Ren, Qian; Wang, Jin-Xing

    2013-12-01

    The immune deficiency (IMD) signal pathway mediates immunity against Gram-negative bacteria in Drosophila. Recent studies show that the IMD pathway also involves in antiviral innate immune responses. The functions of the pathway in crustacean immunity are largely unknown. In this paper, two IMDs (FcIMD and PcIMD), one of the key elements of the IMD pathway, were identified from Chinese white shrimp Fenneropenaeus chinensis and red swamp crayfish Procambarus clarkii. Both proteins have a death domain located at the C-terminal. FcIMD was mainly expressed in the gills and stomach and PcIMD was mainly detected in the heart, hepatopancreas, and stomach. FcIMD peaked in hemocytes at 12 h after white spot syndrome virus (WSSV) challenge and it peaked in the gills at 6 h after WSSV challenge, but it was decreased at 2 h and kept the low level to 24 h in hemocytes and no obviously change in gill after Vibrio anguillarum challenge. PcIMD first decreased in hemocytes at 2 h and peaked at 12 h in hemocytes after V. anguillarum challenge. It was also upregulated in gill after bacterial challenge, peaked at 2 h, and decreased at 6 h, and then gradually increased at 12-24 h. PcIMD has no significant change in hemocytes and gill after WSSV challenge. Western blot analysis detected FcIMD protein in all tissues, and immunocytochemical analysis localized FcIMD in the cytoplasm of hemocytes. RNA interference analysis showed that the IMD pathway was involved in regulating the expression of three kinds AMP genes, including crustins, anti-lipopolysaccharide factors and lysozymes, in shrimp and crayfish. They are Cru 1, Cru 2, ALF 1, ALF 2 and Lys 1 in crayfish, and Cru1, Cru 3, ALF 6, ALF 8, and Lys2 in shrimp. These results suggest that although IMD distribution and expression patterns have some differences, the IMD pathway may have conserved function for AMP regulation in shrimp and crayfish immunity against Gram-negative bacteria.

  1. Telepsychiatry in juvenile justice settings.

    PubMed

    Kaliebe, Kristopher E; Heneghan, James; Kim, Thomas J

    2011-01-01

    Telepsychiatry is emerging as a valuable means of providing mental health care in juvenile justice settings. Youth in the juvenile justice system have high levels of psychiatric morbidity. State and local juvenile justice systems frequently struggle to provide specialized psychiatric care, as these systems have limited resources and often operate in remote locations. Case studies in the use of telepsychiatry to provide improved care in juvenile corrections in 4 states are described, along with a review of advantages and disadvantages of telepsychiatry in these settings. PMID:21092916

  2. Telepsychiatry in juvenile justice settings.

    PubMed

    Kaliebe, Kristopher E; Heneghan, James; Kim, Thomas J

    2011-01-01

    Telepsychiatry is emerging as a valuable means of providing mental health care in juvenile justice settings. Youth in the juvenile justice system have high levels of psychiatric morbidity. State and local juvenile justice systems frequently struggle to provide specialized psychiatric care, as these systems have limited resources and often operate in remote locations. Case studies in the use of telepsychiatry to provide improved care in juvenile corrections in 4 states are described, along with a review of advantages and disadvantages of telepsychiatry in these settings.

  3. Self-limiting outbreak of crayfish plague in an Austropotamobius pallipes population of a river basin in the Abruzzi region (central Italy).

    PubMed

    Caprioli, Riccardo; Cargini, Daniele; Marcacci, Maurilia; Cammà, Cesare; Giansante, Carla; Ferri, Nicola

    2013-03-26

    Crayfish plague, caused by the oomycete Aphanomyces astaci, is a serious disease of European freshwater crayfish and has eliminated entire populations in several European countries. In September 2011, mortality was observed among the Austropotamobius pallipes population of a river basin in the Abruzzi region (central Italy), and A. astaci DNA was detected by PCR in dead crayfish. A systematic survey was carried out to evaluate the spread and the effects of the plague in the river basin. The source of the outbreak remained unknown since North American crayfish species, which frequently act as subclinical carriers of the infection, were not detected in the area. The A. pallipes population disappeared from a river stretch of ~1 km, where A. astaci infection was detected in dead crayfish. However, apparently unaffected crayfish were still present upstream of that area as well as in a tributary that joined the brook in the apparently depopulated stretch. A. astaci infection was not detected in dead individuals collected in the upstream area and tributary. A follow-up visit conducted in the following season showed the presence of A. pallipes in the river stretch hit by the plague. In this outbreak, the spread of the infection could have been limited by a low density of the crayfish population and by the geographic conformation of the river basin, which includes a dense network of small tributaries, characterized by high flow velocity and low water temperature. In this particular setting, crayfish plague outbreaks can remain undetected. This underlines the importance of active monitoring programs aimed at the prompt recognition of both episodes of mortality and the presence of non-indigenous crayfish species.

  4. Zinc and cadmium concentrations in soft tissues of the red swamp crayfish Procambarus clarkii (Girard, 1852) after exposure to zinc and cadmium

    SciTech Connect

    Maranhao, P.; Marques, J.C.; Madeira, V.M.C.

    1999-08-01

    Zinc and cadmium concentrations in crayfish (Procambarus clarkii) soft tissues (as edible portion) were measured after exposure to zinc and cadmium at 0, 25, 50, or 100 {micro}g/L for 96 h at 10 or 20 C, and compared to environmental standards for human consumption. Results demonstrated that no significant change occurred in the concentrations of zinc in soft tissues of crayfish under the given conditions. Net accumulation of cadmium was observed at all experimental exposures, and exceeded the maximum allowed for human consumption only for those crayfish exposed to 100 {micro}g/L at 20 C.

  5. Improving Literacy Skills of Juvenile Detainees. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Hodges, Jane; And Others

    The Office of Juvenile and Delinquency Prevention funded a model designed to improve the literacy level of youth in juvenile detention and correctional facilities. The model specified training language arts teachers and relevant staff and volunteers in direct instruction methods for rapid improvement of students' comprehension, particularly for…

  6. Juvenile Mentoring Program: A Progress Review. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Novotney, Laurence C.; Mertinko, Elizabeth; Lange, James; Baker, Tara Kelley

    The greatest support offered by the Office of Juvenile Justice and Delinquency Prevention for youth mentoring has been through the Juvenile Mentoring Program (JUMP), which provides one-to-one mentoring for youth at risk of delinquency, gang involvement, educational failure, or dropping out of school. Information on JUMP has been collected through…

  7. Serious and Violent Juvenile Offenders. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Department of Justice, Washington, DC. Office of Juvenile Justice and Delinquency Prevention.

    This bulletin summarizes the latest and most comprehensive research and serious and violent juvenile (SJV) offenders taken from a report by the Study Group on Serious and Violent Juvenile Offenders. It describes characteristics of SVJ offenders and predictors of SVJ offending. Some interventions to prevent offenses by SVJs are reviewed. Recently…

  8. Differences Found in the Macroinvertebrate Community Composition in the Presence or Absence of the Invasive Alien Crayfish, Orconectes hylas.

    PubMed

    Freeland-Riggert, Brandye T; Cairns, Stefan H; Poulton, Barry C; Riggert, Christopher M

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities. PMID:26986207

  9. Evolution of invasive traits in nonindigenous species: increased survival and faster growth in invasive populations of rusty crayfish (Orconectes rusticus).

    PubMed

    Sargent, Lindsey W; Lodge, David M

    2014-09-01

    The importance of evolution in enhancing the invasiveness of species is not well understood, especially in animals. To evaluate evolution in crayfish invasions, we tested for differences in growth rate, survival, and response to predators between native and invaded range populations of rusty crayfish (Orconectes rusticus). We hypothesized that low conspecific densities during introductions into lakes would select for increased investment in growth and reproduction in invasive populations. We reared crayfish from both ranges in common garden experiments in lakes and mesocosms, the latter in which we also included treatments of predatory fish presence and food quality. In both lake and mesocosm experiments, O. rusticus from invasive populations had significantly faster growth rates and higher survival than individuals from the native range, especially in mesocosms where fish were present. There was no influence of within-range collection location on growth rate. Egg size was similar between ranges and did not affect crayfish growth. Our results, therefore, suggest that growth rate, which previous work has shown contributes to strong community-level impacts of this invasive species, has diverged since O. rusticus was introduced to the invaded range. This result highlights the need to consider evolutionary dynamics in invasive species mitigation strategies.

  10. Evolution of invasive traits in nonindigenous species: increased survival and faster growth in invasive populations of rusty crayfish (Orconectes rusticus)

    PubMed Central

    Sargent, Lindsey W; Lodge, David M

    2014-01-01

    The importance of evolution in enhancing the invasiveness of species is not well understood, especially in animals. To evaluate evolution in crayfish invasions, we tested for differences in growth rate, survival, and response to predators between native and invaded range populations of rusty crayfish (Orconectes rusticus). We hypothesized that low conspecific densities during introductions into lakes would select for increased investment in growth and reproduction in invasive populations. We reared crayfish from both ranges in common garden experiments in lakes and mesocosms, the latter in which we also included treatments of predatory fish presence and food quality. In both lake and mesocosm experiments, O. rusticus from invasive populations had significantly faster growth rates and higher survival than individuals from the native range, especially in mesocosms where fish were present. There was no influence of within-range collection location on growth rate. Egg size was similar between ranges and did not affect crayfish growth. Our results, therefore, suggest that growth rate, which previous work has shown contributes to strong community-level impacts of this invasive species, has diverged since O. rusticus was introduced to the invaded range. This result highlights the need to consider evolutionary dynamics in invasive species mitigation strategies. PMID:25469173

  11. Differences Found in the Macroinvertebrate Community Composition in the Presence or Absence of the Invasive Alien Crayfish, Orconectes hylas

    PubMed Central

    Freeland-Riggert, Brandye T.

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities. PMID:26986207

  12. Predicting probability of occurrence and factors affecting distribution and abundance of three Ozark endemic crayfish species at multiple spatial scales

    USGS Publications Warehouse

    Nolen, Matthew S.; Magoulick, Daniel D.; DiStefano, Robert J.; Imhoff, Emily M.; Wagner, Brian K.

    2014-01-01

    We found that a range of environmental variables were important in predicting crayfish distribution and abundance at multiple spatial scales and their importance was species-, response variable- and scale dependent. We would encourage others to examine the influence of spatial scale on species distribution and abundance patterns.

  13. Differences found in the macroinvertebrate community composition in the presence or absence of the invasive alien crayfish, Orconectes hylas

    USGS Publications Warehouse

    Freeland-Riggert, Brandye T.; Cairns, Stefan H.; Poulton, Barry C.; Riggert, Chris M.

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities.

  14. Differences Found in the Macroinvertebrate Community Composition in the Presence or Absence of the Invasive Alien Crayfish, Orconectes hylas.

    PubMed

    Freeland-Riggert, Brandye T; Cairns, Stefan H; Poulton, Barry C; Riggert, Christopher M

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities.

  15. Oxidative damage induced by copper and beta-cypermethrin in gill of the freshwater crayfish Procambarus clarkii.

    PubMed

    Wei, Keqiang; Yang, Junxian

    2015-03-01

    Copper (Cu) and pyrethroid are common contaminants found in the aquatic environment, and their potential toxicological effects on aquatic organisms have received extensive attention. However, the impact on crayfish species of exposure to the two chemicals are still largely unknown. The current study assessed the sublethal toxicities induced by Cu and commercial formulation of beta-cypermethrin in the freshwater crayfish Procambarus clarkii. The static test method of acute toxicity test was used. Five biomarkers of oxidative effects, i.e. reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and protein carbonyls, and pathologic changes were determined. The results demonstrated that there was a significant increase in the contents of ROS, MDA and protein carbonyls accompanied by markedly decreased SOD and CAT activities in a concentration-dependent manner. The linear relationship between protein carbonyls induction and MDA formation was observed evidently in crayfish gills at 96h. Higher contents of ROS enhanced the risk of lipid peroxidation and protein carbonylation, thus impacting vital physiological functions of gills. The results indicated that protein oxidation may be one of the main mechanisms of pollution-induced toxicity to crayfish gills. Protein carbonyl levels could be considered as a potential biomarker of exposure to environmental contaminants.

  16. A novel L-type lectin was required for the multiplication of WSSV in red swamp crayfish (Procambarus clakii).

    PubMed

    Dai, Yunjia; Wang, Yuqing; Zhao, Lingling; Qin, Zhendong; Yuan, Junfa; Qin, Qiwei; Lin, Li; Lan, Jiangfeng

    2016-08-01

    L-type lectins are involved in glycoproteins secretory pathways and are associated with many immune responses. There is growing evidence that L-type lectins are also involved in viral replication. In this study, a novel L-type lectin (named as PcL-lectin) was identified from red swamp crayfish (Procambarus clakii). Gene sequencing and phylogenetic tree analysis results showed that the PcL-lectin was a kind of endoplasmic reticulum Golgi intermediate compartment-53 (ERGIC-53). The expression level of PcL-lectin was significantly down regulated in crayfish after challenged with white spot syndrome virus (WSSV). Recombinant PcL-lectin protein facilitated the replication of WSSV in crayfish. In addition, WSSV replication was decreased when endogenous PcL-lectin was knocked down by RNA interference in crayfish. Furthermore, PcL-lectin may interact with VP24, an envelope protein of WSSV. Our results suggest that PcL-lectin may be required for the multiplication of WSSV, and will pave a new way for the developing of strategies against WSSV infection. PMID:27208793

  17. Effect of Chronic Exposure to Prometryne on Oxidative Stress and Antioxidant Response in Red Swamp Crayfish (Procambarus clarkii)

    PubMed Central

    Stará, Alžběta; Kouba, Antonín; Velíšek, Josef

    2014-01-01

    The aim of the study was to investigate effects of the triazine herbicide prometryne on red swamp crayfish on the basis of oxidative stress, antioxidant indices in hepatopancreas and muscle, and histopathology of hepatopancreas. Crayfish were exposed to prometryne concentrations of 0.51 μg L−1, 0.144 mg L−1, and 1.144 mg L−1 for 11 and 25 days. Indices of oxidative stress (thiobarbituric acid reactive substances (TBARS)), and antioxidant parameters (superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR)) in crayfish muscle and hepatopancreas were measured. Chronic exposure to prometryne did not showed the impact of oxidative damage to cells. Changes activity of the antioxidant enzymes SOD, CAT, and GR were observed in all tested concentrations to prometryne for 11 and 25 days (P < 0.01) as compared with the control group. We did not see any differences in histopatological examination to hepatopancreas. Prolonged exposure of prometryne did not result in oxidative damage to cell lipids and proteins, but it led to changes in antioxidant activity in crayfish tissues. Changes in antioxidant systems were also observed in the environmental prometryne concentration of 0.51 μg L−1. The results suggest that antioxidant responses may have potential as biomarkers for monitoring residual triazine herbicides in aquatic environments. PMID:24757669

  18. Juvenile hyaline fibromatosis.

    PubMed

    Larralde, M; Santos-Muñoz, A; Calb, I; Magariños, C

    2001-01-01

    Juvenile hyaline fibromatosis (JHF) is a rare autosomal recessive disease with onset in infancy or early childhood. It is characterized by papulonodular skin lesions, soft tissue masses, gingival hypertrophy, and flexion contractures of the large joints. The light and electron microscopic features are very distinctive. Here we report an 8-month-old boy with characteristic stiffness of the knees and elbows and pink confluent papules on the paranasal folds, and periauricular and perianal regions. He also had hard nodules all over the scalp and around the mouth, and severe gingival hypertrophy. Histologic and ultrastructural features were typical of JHF. Clinical features, pathology, and physiology are discussed.

  19. Juvenile psittacine environmental enrichment.

    PubMed

    Simone-Freilicher, Elisabeth; Rupley, Agnes E

    2015-05-01

    Environmental enrichment is of great import to the emotional, intellectual, and physical development of the juvenile psittacine and their success in the human home environment. Five major types of enrichment include social, occupational, physical, sensory, and nutritional. Occupational enrichment includes exercise and psychological enrichment. Physical enrichment includes the cage and accessories and the external home environment. Sensory enrichment may be visual, auditory, tactile, olfactory, or taste oriented. Nutritional enrichment includes variations in appearance, type, and frequency of diet, and treats, novelty, and foraging. Two phases of the preadult period deserve special enrichment considerations: the development of autonomy and puberty.

  20. Juvenile nasopharyngeal angiofibroma.

    PubMed

    Blount, Angela; Riley, Kristen O; Woodworth, Bradford A

    2011-08-01

    Juvenile nasopharyngeal angiofibromas (JNAs) are rare, benign, highly vascular, locally aggressive tumors that primarily affect male adolescents. Historical treatment of these neoplasms has been primarily surgical. In the past decade, endoscopic resection of JNAs has become a viable and promising surgical treatment option. Endoscopic resection has many advantages over traditional open techniques, including better cosmesis, decreased blood loss, shortened hospital stays, and equivalent or improved recurrence rates. Emerging endoscopic technology continues to push the boundaries of resection of skull base tumors and will no doubt become the surgical treatment of choice for most JNAs in the near future.

  1. Juvenile Dermatomyositis in Pregnancy

    PubMed Central

    Madu, Anthony Emeka; Omih, Edwin; Baguley, Elaine; Lindow, Stephen W.

    2013-01-01

    Juvenile dermatomyositis has variable clinical presentations both in and outside of pregnancy. A literature review indicated that optimal maternal and fetal outcomes can be anticipated when the pregnancy is undertaken while the disease is in remission. Poorer outcomes are associated with flare-up of the disease in early pregnancy compared with exacerbation in the second or third trimester, when fetal prognosis is usually good. We present a case of JDM in pregnancy with disease exacerbation late in pregnancy and review of the relevant literature. PMID:23662227

  2. Juvenile dermatomyositis in pregnancy.

    PubMed

    Madu, Anthony Emeka; Omih, Edwin; Baguley, Elaine; Lindow, Stephen W

    2013-01-01

    Juvenile dermatomyositis has variable clinical presentations both in and outside of pregnancy. A literature review indicated that optimal maternal and fetal outcomes can be anticipated when the pregnancy is undertaken while the disease is in remission. Poorer outcomes are associated with flare-up of the disease in early pregnancy compared with exacerbation in the second or third trimester, when fetal prognosis is usually good. We present a case of JDM in pregnancy with disease exacerbation late in pregnancy and review of the relevant literature.

  3. Immune responses of prophenoloxidase and cytosolic manganese superoxide dismutase in the freshwater crayfish Cherax quadricarinatus against a virus and bacterium.

    PubMed

    Liu, Yan-Ting; Chang, Chin-I; Hseu, Jinn-Rong; Liu, Kuan-Fu; Tsai, Jyh-Ming

    2013-11-01

    Prophenoloxidase (proPO) and cytosolic manganese superoxide dismutase (cytMnSOD) play crucial roles in crustacean innate immunity. In the present study, both of the above genes were cloned from hemocytes of the red claw crayfish Cherax quadricarinatus. A phylogenetic analysis of the amino acid sequences showed that C. quadricarinatus proPO and cytMnSOD were more closely related to the proPO and cytMnSOD of other crayfish than to those of penaeids, crabs, lobsters, or freshwater prawns. A tissue distribution analysis revealed that proPO was primarily expressed in hemocytes, gills, and the heart, while cytMnSOD was detected in all tissues examined. All of the crayfish artificially infected with white spot syndrome virus (WSSV) died within 4 days. According to a non-lethal dose, there was no mortality in crayfish when infected deliberately with Aeromonas hydrophila. Total hemocyte counts (THCs) had significantly decreased in crayfish at 48 and 72 h after infection with WSSV compared to the control group. In contrast, THCs of crayfish after A. hydrophila challenge had recovered by 48 and 72 h from a lower level at 24 h. There were similar responses in enzyme activities toward WSSV and A. hydrophila infection. Phenoloxidase (PO) and superoxide dismutase (SOD) activities per hemocyte significantly increased from 48 to 72 h compared to the control group. After WSSV challenge, expressions of proPO and cytMnSOD transcripts in hemocytes significantly decreased at 12h, then had respectively recovered and increased at 24 h. At 48-72 h, transcript levels were finally downregulated. No significant differences in the expression profiles of proPO and cytMnSOD were observed between the A. hydrophila-infected and control groups, besides the significant upregulation at 24h post-infection. These results implicate proPO and cytMnSOD in the immune response, and they presented similar expression patterns, although different defense mechanisms may exist for crayfish induced by WSSV and A

  4. Population structure and genetic analysis of narrow-clawed crayfish (Astacus leptodactylus) populations in Turkey.

    PubMed

    Akhan, Suleyman; Bektas, Yusuf; Berber, Selcuk; Kalayci, Gokhan

    2014-10-01

    The genetic differentiation among Turkish populations of the narrow-clawed crayfish was investigated using a partial sequence of cytochrome oxidase subunit I gene (585 bp) of 183 specimens from 17 different crayfish populations. Median joining network and all phylogenetic analyses disclosed a strong haplotype structure with three prominent clades diverged by a range between 20 and 50 mutations and substantial inter-group pairwise sequence divergence (5.19-6.95 %), suggesting the presence of three distinct clades within the Anatolian populations of Astacus leptodactylus. The divergence times among the three clades of Turkish A. leptodactylus are estimated to be 4.96-3.70 Mya using a molecular clock of 1.4 % sequence divergence per million years, pointing to a lower Pliocene separation. The high level of genetic variability (H d = 95.8 %, π = 4.17 %) and numerous private haplotypes suggest the presence of refugial populations in Anatolia unaffected by Pleistocene habitat restrictions. The pattern of genetic variation among Turkish A. leptodactylus populations, therefore, suggests that the unrevealed intraspecific genetic structure is independent of geographic tendency and congruent with the previously reported geographic distribution and number of subspecies (A. l. leptodactylus and A. l. salinus) of A. leptodactylus.

  5. Glutamate-mediated protection of crayfish glial cells from PDT-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Rudkovskii, M. V.; Romanenko, N. P.; Berezhnaya, E. V.; Kovaleva, V. D.; Uzdensky, A. B.

    2010-10-01

    Photodynamic treatment that causes intense oxidative stress and kills cells is currently used in neurooncology. However, along with tumor it damages surrounding healthy neurons and glial cells. In order to study the possible role of glutamate-related signaling pathways in photodynamic injury of neurons and glia, we investigated photodynamic effect of alumophthalocyanine Photosens on isolated crayfish stretch receptor that consists of a single neuron surrounded by glial cells. The laser diode (670 nm, 0.4 W/cm2) was used for dye photoexcitation. Application of glutamate increased photodynamically induced necrosis of neurons and glial cells but significantly decreased glial apoptosis. The natural neuroglial mediator N-acetylaspartylglutamate, which releases glutamate after cleavage in the extracellular space by glutamate carboxypeptidase II, also inhibited photoinduced apoptosis. Inhibition of glutamate carboxypeptidase II, oppositely, enhanced apoptosis of glial cells. These data confirm the anti-apoptotic activity of glutamate. Application of NMDA or inhibition of NMDA receptors by MK801 did not influence photodynamic death of neurons and glial cells that indicated nonparticipation of NMDA receptors in these processes. Inhibition of metabotropic glutamate receptors by AP-3 decreased PDT-induced apoptosis. One can suggest that crayfish neurons naturally secrete NAAG, which being cleaved by GCOP produces glutamate. Glutamate prevents photoinduced apoptosis of glial cells possibly through metabotropic but not ionotropic glutamate receptors.

  6. Glutamate-mediated protection of crayfish glial cells from PDT-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Rudkovskii, M. V.; Romanenko, N. P.; Berezhnaya, E. V.; Kovaleva, V. D.; Uzdensky, A. B.

    2011-03-01

    Photodynamic treatment that causes intense oxidative stress and kills cells is currently used in neurooncology. However, along with tumor it damages surrounding healthy neurons and glial cells. In order to study the possible role of glutamate-related signaling pathways in photodynamic injury of neurons and glia, we investigated photodynamic effect of alumophthalocyanine Photosens on isolated crayfish stretch receptor that consists of a single neuron surrounded by glial cells. The laser diode (670 nm, 0.4 W/cm2) was used for dye photoexcitation. Application of glutamate increased photodynamically induced necrosis of neurons and glial cells but significantly decreased glial apoptosis. The natural neuroglial mediator N-acetylaspartylglutamate, which releases glutamate after cleavage in the extracellular space by glutamate carboxypeptidase II, also inhibited photoinduced apoptosis. Inhibition of glutamate carboxypeptidase II, oppositely, enhanced apoptosis of glial cells. These data confirm the anti-apoptotic activity of glutamate. Application of NMDA or inhibition of NMDA receptors by MK801 did not influence photodynamic death of neurons and glial cells that indicated nonparticipation of NMDA receptors in these processes. Inhibition of metabotropic glutamate receptors by AP-3 decreased PDT-induced apoptosis. One can suggest that crayfish neurons naturally secrete NAAG, which being cleaved by GCOP produces glutamate. Glutamate prevents photoinduced apoptosis of glial cells possibly through metabotropic but not ionotropic glutamate receptors.

  7. How toxic is the depleted uranium to crayfish Procambarus clarkii compared with cadmium?

    PubMed

    Al Kaddissi, Simone; Simon, Olivier; Elia, Antonia Concetta; Gonzalez, Patrice; Floriani, Magali; Cavalie, Isabelle; Camilleri, Virginie; Frelon, Sandrine; Legeay, Alexia

    2016-02-01

    Due to a lack of information on the assessment of uranium's (U) toxicity, our work aimed to compare the effects of U on the crayfish Procambarus clarkii with those of the well documented metal: cadmium (Cd). Accumulation and impacts at different levels of biological organization were assessed after acute (40 µM Cd or U; 4-10 days) and chronic (0.1 µM Cd or U; 30-60 days) exposures. The survival rates demonstrated the high tolerance of this species toward both metals and showed that Cd had a greater effect on the sustainability of crayfish. The concentration levels of Cd and U accumulated in gills and hepatopancreas were compared between both conditions. Distinctions in the adsorption capacities and the mobility of the contaminants were suspected. Differences in the detoxification mechanisms of both metals using transmission electron microscopy equiped with an energy dispersive X-ray were also pointed out. In contrast, comparison between the histological structures of contaminated hepatopancreas showed similar symptoms. Principal component analyses revealed different impacts of each metal on the oxidative balance and mitochondria using enzymatic activities and gene expression levels as endpoints. The observation that U seemed to generate more oxidative stress than Cd in our conditions of exposure is discussed.

  8. Preliminary investigation of effects of sublethal acid exposure on maternal behavior in the Crayfish Orconectes virilis

    SciTech Connect

    France, R.L.

    1985-11-01

    The occurrence of crayfish inhabiting the littoral regions of many oligotrophic acid sensitive lakes makes these organisms vulnerable to spring pH decreases. Egg extrusion in Orconectes spp. found in south-central Ontario is generally synchronous and occurs during or slightly after ice melting in late April, a time at which these lakes receive between 36-77% of the year's export of H from their watersheds. To understand how a toxicant affects crayfish reproduction it is necessary that the maternal and embryonic responses to experimental perturbation be separated. In an acidified lake in the Experimental Lakes Area, northwestern Ontario, 6.9-16.9% of the egg-bearing females experienced partial mortality of their broods at pH 5.4-5.6. An ancillary experiment was undertaken here to determine if this egg mortality could be a result of low pH-induced behavioral modification of the maternal female, rather than direct acid toxicity to the developing eggs.

  9. Soluble guanylyl cyclase is involved in PDT-induced injury of crayfish glial cells

    NASA Astrophysics Data System (ADS)

    Kovaleva, V. D.; Uzdensky, A. B.

    2016-04-01

    Photodynamic therapy (PDT) is a potential tool for selective destruction of malignant brain tumors. However, not only malignant but also healthy neurons and glial cells may be damaged during PDT. Nitric oxide is an important modulator of cell viability and intercellular neuroglial communications. NO have been already shown to participate in PDT-induced injury of neurons and glial cells. As soluble guanylyl cyclase is the only known receptor for NO, we have studied the possible role of soluble guanylyl cyclase in the regulation of survival and death of neurons and surrounding glial cells under photo-oxidative stress induced by photodynamic treatment (PDT). The crayfish stretch receptor consisting of a single identified sensory neuron enveloped by glial cells is a simple but informative model object. It was photosensitized with alumophthalocyanine photosens (10 nM) and irradiated with a laser diode (670 nm, 0.4 W/cm2). Using inhibitory analysis we have shown that during PDT soluble guanylyl cyclase, probably, has proapoptotic and antinecrotic effect on the glial cells of the isolated crayfish stretch receptor. Proapoptotic effect of soluble guanylyl cyclase could be mediated by protein kinase G (PKG). Thus, the involvement of NO/sGC/cGMP/PKG signaling pathway in PDT-induced apoptosis of glial cells was indirectly demonstrated.

  10. Effects of cadmium on the biochemical composition of the freshwater crayfish Procambarus clarkii (Girard, 1852)

    SciTech Connect

    Torreblanca, A.; Del Ramo, J.; Diaz-Mayans, J. )

    1991-12-01

    Lake Albufera of Valencia (Spain) and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic residues. Among these residues include heavy metals which have been deposited from the many urban and waste waters in this area. The American red crayfish, Procambarus clarkii from Albufera Lake has high resistance to heavy metals. The authors have also found that P. clarkii shows a high capacity for cadmium accumulation in experimental conditions and natural conditions since crayfish collected in this area contained considerable amounts of cadmium in several tissues even after 15 days of depuration in clean water. Since the physiological changes that take place when organisms are exposed to sublethal levels of stress could include rate of feeding as well as respiration and excretion, the net result could be a change in energy available for growth and reproduction. In this work, the authors have studied the biochemical energy composition of hepatopancreas, muscle and gills of P. clarkii after short term sublethal exposure to cadmium.

  11. Examining the crayfish, Astacus pallipes, in foodweb transfers of nonpolar contaminants from Dreissena polymorpha

    SciTech Connect

    Gossiaux, D.; Landrum, P.F.

    1995-12-31

    Crayfish, Astacus pallipes, were exposed to dissolved non-polar PAH and PCB congeners in short term water-only exposures. Uptake and elimination rate constants were determined for total body mass and internal organ tissues. The uptake clearance was slow (ranging 14--44 ml g{sup {minus}1}h{sup {minus}1}) and negatively related to total body mass but positively correlated with log K{sub ow}. Individual tissues, ovary, hepatopancreas and muscle in the thorax, all showed decreased uptake rate coefficients, (k{sub u}) with increased tissue mass and increased with log K{sub ow}. The elimination rates were also slow (ranging 0.002--0.019 h{sup {minus}1}) and decreased with increasing log K{sub ow}. The ovaries eliminated the contaminants most rapidly while the thorax muscle was slowest. In addition to water-only exposures, the predation of crayfish on the zebra mussel Dreissena polymorpha and estimated uptake rates associated with ingestion of zebra mussel tissue when the mussels are preexposed to radiolabeled contaminants will be described.

  12. Australian spiny mountain crayfish and their temnocephalan ectosymbionts: an ancient association on the edge of coextinction?

    PubMed

    Hoyal Cuthill, Jennifer F; Sewell, Kim B; Cannon, Lester R G; Charleston, Michael A; Lawler, Susan; Littlewood, D Timothy J; Olson, Peter D; Blair, David

    2016-05-25

    Australian spiny mountain crayfish (Euastacus, Parastacidae) and their ecotosymbiotic temnocephalan flatworms (Temnocephalida, Platyhelminthes) may have co-occurred and interacted through deep time, during a period of major environmental change. Therefore, reconstructing the history of their association is of evolutionary, ecological, and conservation significance. Here, time-calibrated Bayesian phylogenies of Euastacus species and their temnocephalans (Temnohaswellia and Temnosewellia) indicate near-synchronous diversifications from the Cretaceous. Statistically significant cophylogeny correlations between associated clades suggest linked evolutionary histories. However, there is a stronger signal of codivergence and greater host specificity in Temnosewellia, which co-occurs with Euastacus across its range. Phylogeography and analyses of evolutionary distinctiveness (ED) suggest that regional differences in the impact of climate warming and drying had major effects both on crayfish and associated temnocephalans. In particular, Euastacus and Temnosewellia show strong latitudinal gradients in ED and, conversely, in geographical range size, with the most distinctive, northern lineages facing the greatest risk of extinction. Therefore, environmental change has, in some cases, strengthened ecological and evolutionary associations, leaving host-specific temnocephalans vulnerable to coextinction with endangered hosts. Consequently, the extinction of all Euastacus species currently endangered (75%) predicts coextinction of approximately 60% of the studied temnocephalans, with greatest loss of the most evolutionarily distinctive lineages. PMID:27226467

  13. Effects of terbuthylazine-desethyl, a terbuthylazine degradation product, on red swamp crayfish (Procambarus clarkii).

    PubMed

    Stara, Alzbeta; Zuskova, Eliska; Kouba, Antonin; Velisek, Josef

    2016-10-01

    Terbuthylazine is a widely used triazine pesticide. This, together with one of its degradation products, terbuthylazine-desethyl (TD), are frequently found in quantities exceeding the EU limit of 0.1μg/L in aquatic ecosystems where they might constitute a serious risk to non-target organisms. The sub-chronic effects of TD at 2.9μg/L (real environmental concentration) and at 580μg/L were investigated in a non-target aquatic species, the red swamp crayfish (Procambarus clarkii). Gill and hepatopancreas histopathology, alterations in biochemical parameters of haemolymph, oxidative damage to hepatopancreas, and changes in antioxidant biomarkers in muscle and hepatopancreas were recorded at both tested concentrations after 14days exposure. A 14day recovery period in TD-free water was not sufficient for restoration of normal parameters. Chronic terbuthylazine-desethyl exposure affected biochemical profile, and the antioxidant system, caused oxidative stress and histopathological changes in hepatopancreas of red swamp crayfish. PMID:27239716

  14. Australian spiny mountain crayfish and their temnocephalan ectosymbionts: an ancient association on the edge of coextinction?

    PubMed

    Hoyal Cuthill, Jennifer F; Sewell, Kim B; Cannon, Lester R G; Charleston, Michael A; Lawler, Susan; Littlewood, D Timothy J; Olson, Peter D; Blair, David

    2016-05-25

    Australian spiny mountain crayfish (Euastacus, Parastacidae) and their ecotosymbiotic temnocephalan flatworms (Temnocephalida, Platyhelminthes) may have co-occurred and interacted through deep time, during a period of major environmental change. Therefore, reconstructing the history of their association is of evolutionary, ecological, and conservation significance. Here, time-calibrated Bayesian phylogenies of Euastacus species and their temnocephalans (Temnohaswellia and Temnosewellia) indicate near-synchronous diversifications from the Cretaceous. Statistically significant cophylogeny correlations between associated clades suggest linked evolutionary histories. However, there is a stronger signal of codivergence and greater host specificity in Temnosewellia, which co-occurs with Euastacus across its range. Phylogeography and analyses of evolutionary distinctiveness (ED) suggest that regional differences in the impact of climate warming and drying had major effects both on crayfish and associated temnocephalans. In particular, Euastacus and Temnosewellia show strong latitudinal gradients in ED and, conversely, in geographical range size, with the most distinctive, northern lineages facing the greatest risk of extinction. Therefore, environmental change has, in some cases, strengthened ecological and evolutionary associations, leaving host-specific temnocephalans vulnerable to coextinction with endangered hosts. Consequently, the extinction of all Euastacus species currently endangered (75%) predicts coextinction of approximately 60% of the studied temnocephalans, with greatest loss of the most evolutionarily distinctive lineages.

  15. Evolutionary History and Conservation Status of Cave Crayfishes Along the Cumberland Plateau

    NASA Astrophysics Data System (ADS)

    Buhay, J. E.; Crandall, K. A.

    2005-05-01

    Obligate cave-dwelling crayfish species are found only in southeastern United States, Mexico, and Cuba. Most species are considered to be endangered because of surface pollution threats to groundwater and small geographic distributions. There are currently three subterranean species of the genus Orconectes found along the Cumberland Plateau, a worldwide hotspot of cave biodiversity. The objectives of my dissertation research are to: 1) delineate species' boundaries using molecular genetic data in a phylogenetic framework, 2) examine evolutionary history of each species using Nested Clade Analysis, and 3) assess conservation status of each species using measures of effective population size and genetic diversity. This research project has uncovered a new species of cave crayfish along the border of Tennessee and Kentucky, an area previously thought to have "intergrades" between two subspecies of O. australis. It appears that Cambarus gentryi, a surface-dwelling burrowing species, is the closest living ancestor to the cave Orconectes assemblage on the Plateau. The origin appears to be Eastern Kentucky, with range expansions occuring southward down the Plateau. Although controversial, these cave species exhibit high levels of genetic diversity, especially in comparison to surface-dwellers. Conservation efforts should focus on protecting `high-traffic' areas to maintain gene flow and prevent isolation.

  16. Markers of oxidative stress in hepatopancreas of crayfish (Orconectes limosus, raf) experimentally exposed to nanosilver.

    PubMed

    Strużyński, Witold; Dąbrowska-Bouta, Beata; Grygorowicz, Tomasz; Ziemińska, Elżbieta; Strużyńska, Lidia

    2014-11-01

    Silver nanoparticles, chemically neutral particles in the size range of 1-100 nm, express strong antimicrobial activity and therefore have a broad range of applications. The increased use of consumer products with nanosilver (nanoAg) may result in its release into the environment, and may particularly affect aquatic systems. The mechanisms of the harmful effects of nanoAg against aquatic organisms are unclear. Therefore, in the present study we investigate the pro-oxidative potential of these nanoparticles in experimentally exposed crayfish Orconectes limosus. Markers of oxidative stress and parameters of the antioxidant cell defense system such as total glutathione, glutathione reductase and the level of sulfhydryl groups were examined in the hepatopancreas of both sexes of O. limosus collected seasonally from Białe Lake (Poland) and subsequently exposed to nanoAg particles for 2 weeks. Exposure to nanoAg led to a high concentration-dependent increase in the rate of lipid peroxidation and a decrease of protein-bound SH groups which indicates protein oxidation. These markers of oxidative stress were accompanied by decreased levels of thiols and reduced activity of glutathione reductase. These results indicate a deficiency of reduced glutathione and suggest that the exposed organisms have less efficient antioxidative mechanisms available to counter ROS-mediated cellular stress. Furthermore, we find that confocal microscopy is of limited utility in monitoring the presence of silver nanoparticles in tissues of exposed crayfish.

  17. Preparation of transgenic Dunaliella salina for immunization against white spot syndrome virus in crayfish.

    PubMed

    Feng, Shuying; Feng, Wenpo; Zhao, Ling; Gu, Huihui; Li, Qinghua; Shi, Ke; Guo, Sanxing; Zhang, Nannan

    2014-03-01

    Although a white spot syndrome virus (WSSV) subunit vaccine could significantly enhance the immune response and benefit the shrimp host, its practical application is currently not feasible because of drawbacks in existing expression systems. We generated a transgenic Dunaliella salina (D. salina) strain by introducing the WSSV VP28 gene to produce a novel oral WSSV subunit vaccine. Following transformation of D. salina, VP28 gene expression was assessed by reverse transcription polymerase chain reaction (RT-PCR) assays, enzyme-linked immunosorbent assays (ELISAs), and western blot analysis. The RT-PCR results indicated that the VP28 gene was successfully expressed in D. salina cells. The presence of recombinant VP28 proteins with natural bioactivity was confirmed by western blot analysis and ELISA. Animal vaccination experiments indicated that transgenic D. salina can induce protection against WSSV by oral delivery in crayfish. Our findings indicate that the VP28 gene can be successfully expressed in transgenic D. salina and can be applied as an oral vaccine to protect crayfish against WSSV. We have demonstrated that it is feasible to produce an oral vaccine using D. salina, and thereby provide a new method for controlling other viral diseases in crustaceans.

  18. Direct and indirect effects of an invasive omnivore crayfish on leaf litter decomposition.

    PubMed

    Carvalho, Francisco; Pascoal, Cláudia; Cássio, Fernanda; Sousa, Ronaldo

    2016-01-15

    Invasive alien species (IAS) can disrupt important ecological functions in aquatic ecosystems; however, many of these effects are not quantified and remain speculative. In this study, we assessed the effects of the invasive crayfish Procambarus clarkii (Girard, 1852) on leaf litter decomposition (a key ecosystem process) and associated invertebrates using laboratory and field manipulative experiments. The crayfish had significant impacts on leaf decomposition due to direct consumption of leaf litter and production of fine particulate organic matter, and indirectly due to consumption of invertebrate shredders. The invertebrate community did not appear to recognize P. clarkii as a predator, at least in the first stages after its introduction in the system; but this situation might change with time. Overall, results suggested that the omnivore invader P. clarkii has the potential to affect detritus-based food webs through consumption of basal resources (leaf litter) and/or consumers. Recognizing that this IAS is widespread in Europe, Asia and Africa, and may attain high density and biomass in aquatic ecosystems, our results are important to develop strategies for improving stream ecosystem functioning and to support management actions aiming to control the invasive omnivore P. clarkii. PMID:26437346

  19. Juvenile Justice in Rural America.

    ERIC Educational Resources Information Center

    Jankovic, Joanne, Ed.; And Others

    Producing a much-needed organized body of literature about rural juvenile justice, 14 papers (largely from the 1979 National Symposium on Rural Justice) are organized to identify current issues, identify forces causing changes in current systems, review programs responding to rural juvenile justice problems, and provide planning models to aid…

  20. Psychopathology in Female Juvenile Offenders

    ERIC Educational Resources Information Center

    Dixon, Angela; Howie, Pauline; Starling, Jean

    2004-01-01

    Background: The aim was to document the spectrum of present and lifetime psychological disorders in female juvenile offenders, and to examine the relations between mental health status and socio-demographic, family and trauma variables. Method: One hundred juvenile offenders were matched with a comparison group of 100 females on age and…

  1. Iatrogenic Effect of Juvenile Justice

    ERIC Educational Resources Information Center

    Gatti, Uberto; Tremblay, Richard E.; Vitaro, Frank

    2009-01-01

    Background: The present study uses data from a community sample of 779 low-SES boys to investigate whether intervention by the juvenile justice system is determined, at least in part, by particular individual, familial and social conditions, and whether intervention by the juvenile courts during adolescence increases involvement in adult crime.…

  2. Mental Illness and Juvenile Offenders

    PubMed Central

    Underwood, Lee A.; Washington, Aryssa

    2016-01-01

    Within the past decade, reliance on the juvenile justice system to meet the needs of juvenile offenders with mental health concerns has increased. Due to this tendency, research has been conducted on the effectiveness of various intervention and treatment programs/approaches with varied success. Recent literature suggests that because of interrelated problems involved for youth in the juvenile justice system with mental health issues, a dynamic system of care that extends beyond mere treatment within the juvenile justice system is the most promising. The authors provide a brief overview of the extent to which delinquency and mental illness co-occur; why treatment for these individuals requires a system of care; intervention models; and the juvenile justice systems role in providing mental health services to delinquent youth. Current and future advancements and implications for practitioners are provided. PMID:26901213

  3. Mental Illness and Juvenile Offenders.

    PubMed

    Underwood, Lee A; Washington, Aryssa

    2016-02-18

    Within the past decade, reliance on the juvenile justice system to meet the needs of juvenile offenders with mental health concerns has increased. Due to this tendency, research has been conducted on the effectiveness of various intervention and treatment programs/approaches with varied success. Recent literature suggests that because of interrelated problems involved for youth in the juvenile justice system with mental health issues, a dynamic system of care that extends beyond mere treatment within the juvenile justice system is the most promising. The authors provide a brief overview of the extent to which delinquency and mental illness co-occur; why treatment for these individuals requires a system of care; intervention models; and the juvenile justice systems role in providing mental health services to delinquent youth. Current and future advancements and implications for practitioners are provided.

  4. Mental Illness and Juvenile Offenders.

    PubMed

    Underwood, Lee A; Washington, Aryssa

    2016-02-01

    Within the past decade, reliance on the juvenile justice system to meet the needs of juvenile offenders with mental health concerns has increased. Due to this tendency, research has been conducted on the effectiveness of various intervention and treatment programs/approaches with varied success. Recent literature suggests that because of interrelated problems involved for youth in the juvenile justice system with mental health issues, a dynamic system of care that extends beyond mere treatment within the juvenile justice system is the most promising. The authors provide a brief overview of the extent to which delinquency and mental illness co-occur; why treatment for these individuals requires a system of care; intervention models; and the juvenile justice systems role in providing mental health services to delinquent youth. Current and future advancements and implications for practitioners are provided. PMID:26901213

  5. Constraints upon the response of fish and crayfish to environmental flow releases in a regulated headwater stream network.

    PubMed

    Chester, Edwin T; Matthews, Ty G; Howson, Travis J; Johnston, Kerrylyn; Mackie, Jonathon K; Strachan, Scott R; Robson, Belinda J

    2014-01-01

    In dry climate zones, headwater streams are often regulated for water extraction causing intermittency in perennial streams and prolonged drying in intermittent streams. Regulation thereby reduces aquatic habitat downstream of weirs that also form barriers to migration by stream fauna. Environmental flow releases may restore streamflow in rivers, but are rarely applied to headwaters. We sampled fish and crayfish in four regulated headwater streams before and after the release of summer-autumn environmental flows, and in four nearby unregulated streams, to determine whether their abundances increased in response to flow releases. Historical data of fish and crayfish occurrence spanning a 30 year period was compared with contemporary data (electrofishing surveys, Victoria Range, Australia; summer 2008 to summer 2010) to assess the longer-term effects of regulation and drought. Although fish were recorded in regulated streams before 1996, they were not recorded in the present study upstream or downstream of weirs despite recent flow releases. Crayfish (Geocharax sp. nov. 1) remained in the regulated streams throughout the study, but did not become more abundant in response to flow releases. In contrast, native fish (Gadopsis marmoratus, Galaxias oliros, Galaxias maculatus) and crayfish remained present in unregulated streams, despite prolonged drought conditions during 2006-2010, and the assemblages of each of these streams remained essentially unchanged over the 30 year period. Flow release volumes may have been too small or have operated for an insufficient time to allow fish to recolonise regulated streams. Barriers to dispersal may also be preventing recolonisation. Indefinite continuation of annual flow releases, that prevent the unnatural cessation of flow caused by weirs, may eventually facilitate upstream movement of fish and crayfish in regulated channels; but other human-made dispersal barriers downstream need to be identified and ameliorated, to allow

  6. Serotonin, but not dopamine, controls the stress response and anxiety-like behavior in the crayfish Procambarus clarkii.

    PubMed

    Fossat, Pascal; Bacqué-Cazenave, Julien; De Deurwaerdère, Philippe; Cattaert, Daniel; Delbecque, Jean-Paul

    2015-09-01

    In the animal kingdom, biogenic amines are widespread modulators of the nervous system that frequently interact to control mood. Our previous investigations in crayfish (Procambarus clarkii) have established that stress induces changes in brain serotonin (5-HT) concentrations that are responsible for the appearance of anxiety-like behavior (ALB). Here, we further analyze the roles of 5-HT and another biogenic amine, dopamine (DA), on the crayfish response to stress. We show that the intensity of crayfish ALB depends on the intensity of stressful stimulation and is associated with increased concentrations of 5-HT in the brain. These 5-HT levels were significantly correlated, before, as well as after stress, with those of DA, which were approximately 3- to 5-times less abundant. However, whereas the degree of ALB was clearly correlated with brain 5-HT concentrations, it was not significantly correlated with DA. Moreover, in contrast to injections of 5-HT, DA injections were not able to elicit a stress response or ALB. In addition, 5-HT and DA levels were not modified by treatment with the anxiolytic chlordiazepoxide, confirming that suppression of ALB by this GABA-A receptor ligand acts downstream and is independent of changes in crayfish bioamine levels. Our study also provides evidence that the anxiogenic effect of 5-HT injections can be prevented by a preliminary injection of 5-HT antagonists. Altogether, our results emphasize that the rises in brain concentrations of 5-HT, but not DA, play a role in controlling the induction and the intensity of crayfish ALB.

  7. Morphological and life-history responses of anurans to predation by an invasive crayfish: an integrative approach.

    PubMed

    Nunes, Ana L; Orizaola, Germán; Laurila, Anssi; Rebelo, Rui

    2014-04-01

    Predator-induced phenotypic plasticity has been widely documented in response to native predators, but studies examining the extent to which prey can respond to exotic invasive predators are scarce. As native prey often do not share a long evolutionary history with invasive predators, they may lack defenses against them. This can lead to population declines and even extinctions, making exotic predators a serious threat to biodiversity. Here, in a community-wide study, we examined the morphological and life-history responses of anuran larvae reared with the invasive red swamp crayfish, Procambarus clarkii, feeding on conspecific tadpoles. We reared tadpoles of nine species until metamorphosis and examined responses in terms of larval morphology, growth, and development, as well as their degree of phenotypic integration. These responses were compared with the ones developed in the presence of a native predator, the larval dragonfly Aeshna sp., also feeding on tadpoles. Eight of the nine species altered their morphology or life history when reared with the fed dragonfly, but only four when reared with the fed crayfish, suggesting among-species variation in the ability to respond to a novel predator. While morphological defenses were generally similar across species (deeper tails) and almost exclusively elicited in the presence of the fed dragonfly, life-history responses were very variable and commonly elicited in the presence of the invasive crayfish. Phenotypes induced in the presence of dragonfly were more integrated than in crayfish presence. The lack of response to the presence of the fed crayfish in five of the study species suggests higher risk of local extinction and ultimately reduced diversity of the invaded amphibian communities. Understanding how native prey species vary in their responses to invasive predators is important in predicting the impacts caused by newly established predator-prey interactions following biological invasions. PMID:24834343

  8. Morphological and life-history responses of anurans to predation by an invasive crayfish: an integrative approach.

    PubMed

    Nunes, Ana L; Orizaola, Germán; Laurila, Anssi; Rebelo, Rui

    2014-04-01

    Predator-induced phenotypic plasticity has been widely documented in response to native predators, but studies examining the extent to which prey can respond to exotic invasive predators are scarce. As native prey often do not share a long evolutionary history with invasive predators, they may lack defenses against them. This can lead to population declines and even extinctions, making exotic predators a serious threat to biodiversity. Here, in a community-wide study, we examined the morphological and life-history responses of anuran larvae reared with the invasive red swamp crayfish, Procambarus clarkii, feeding on conspecific tadpoles. We reared tadpoles of nine species until metamorphosis and examined responses in terms of larval morphology, growth, and development, as well as their degree of phenotypic integration. These responses were compared with the ones developed in the presence of a native predator, the larval dragonfly Aeshna sp., also feeding on tadpoles. Eight of the nine species altered their morphology or life history when reared with the fed dragonfly, but only four when reared with the fed crayfish, suggesting among-species variation in the ability to respond to a novel predator. While morphological defenses were generally similar across species (deeper tails) and almost exclusively elicited in the presence of the fed dragonfly, life-history responses were very variable and commonly elicited in the presence of the invasive crayfish. Phenotypes induced in the presence of dragonfly were more integrated than in crayfish presence. The lack of response to the presence of the fed crayfish in five of the study species suggests higher risk of local extinction and ultimately reduced diversity of the invaded amphibian communities. Understanding how native prey species vary in their responses to invasive predators is important in predicting the impacts caused by newly established predator-prey interactions following biological invasions.

  9. Morphological and life-history responses of anurans to predation by an invasive crayfish: an integrative approach

    PubMed Central

    Nunes, Ana L; Orizaola, Germán; Laurila, Anssi; Rebelo, Rui

    2014-01-01

    Predator-induced phenotypic plasticity has been widely documented in response to native predators, but studies examining the extent to which prey can respond to exotic invasive predators are scarce. As native prey often do not share a long evolutionary history with invasive predators, they may lack defenses against them. This can lead to population declines and even extinctions, making exotic predators a serious threat to biodiversity. Here, in a community-wide study, we examined the morphological and life-history responses of anuran larvae reared with the invasive red swamp crayfish, Procambarus clarkii, feeding on conspecific tadpoles. We reared tadpoles of nine species until metamorphosis and examined responses in terms of larval morphology, growth, and development, as well as their degree of phenotypic integration. These responses were compared with the ones developed in the presence of a native predator, the larval dragonfly Aeshna sp., also feeding on tadpoles. Eight of the nine species altered their morphology or life history when reared with the fed dragonfly, but only four when reared with the fed crayfish, suggesting among-species variation in the ability to respond to a novel predator. While morphological defenses were generally similar across species (deeper tails) and almost exclusively elicited in the presence of the fed dragonfly, life-history responses were very variable and commonly elicited in the presence of the invasive crayfish. Phenotypes induced in the presence of dragonfly were more integrated than in crayfish presence. The lack of response to the presence of the fed crayfish in five of the study species suggests higher risk of local extinction and ultimately reduced diversity of the invaded amphibian communities. Understanding how native prey species vary in their responses to invasive predators is important in predicting the impacts caused by newly established predator–prey interactions following biological invasions. PMID:24834343

  10. Can crayfish take the heat? Procambarus clarkii show nociceptive behaviour to high temperature stimuli, but not low temperature or chemical stimuli

    PubMed Central

    Puri, Sakshi; Faulkes, Zen

    2015-01-01

    Nociceptors are sensory neurons that are tuned to tissue damage. In many species, nociceptors are often stimulated by noxious extreme temperatures and by chemical agonists that do not damage tissue (e.g., capsaicin and isothiocyanate). We test whether crustaceans have nociceptors by examining nociceptive behaviours and neurophysiological responses to extreme temperatures and potentially nocigenic chemicals. Crayfish (Procambarus clarkii) respond quickly and strongly to high temperatures, and neurons in the antenna show increased responses to transient high temperature stimuli. Crayfish showed no difference in behavioural response to low temperature stimuli. Crayfish also showed no significant changes in behaviour when stimulated with capsaicin or isothiocyanate compared to controls, and neurons in the antenna did not change their firing rate following application of capsaicin or isothiocyanate. Noxious high temperatures appear to be a potentially ecologically relevant noxious stimulus for crayfish that can be detected by sensory neurons, which may be specialized nociceptors. PMID:25819841

  11. SUMO-conjugating enzyme E2 UBC9 mediates viral immediate-early protein SUMOylation in crayfish to facilitate reproduction of white spot syndrome virus.

    PubMed

    Chen, An-Jing; Gao, Lu; Wang, Xian-Wei; Zhao, Xiao-Fan; Wang, Jin-Xing

    2013-01-01

    Successful viruses have evolved superior strategies to escape host defenses or exploit host biological pathways. Most of the viral immediate-early (ie) genes are essential for viral infection and depend solely on host proteins; however, the molecular mechanisms are poorly understood. In this study, we focused on the modification of viral IE proteins by the crayfish small ubiquitin-related modifier (SUMO) and investigated the role of SUMOylation during the viral life cycle. SUMO and SUMO ubiquitin-conjugating enzyme 9 (UBC9) involved in SUMOylation were identified in red swamp crayfish (Procambarus clarkii). Both SUMO and UBC9 were upregulated in crayfish challenged with white spot syndrome virus (WSSV). Replication of WSSV genes increased in crayfish injected with recombinant SUMO or UBC9, but injection of mutant SUMO or UBC9 protein had no effect. Subsequently, we analyzed the mechanism by which crayfish SUMOylation facilitates WSSV replication. Crayfish UBC9 bound to all three WSSV IE proteins tested, and one of these IE proteins (WSV051) was covalently modified by SUMO in vitro. The expression of viral ie genes was affected and that of late genes was significantly inhibited in UBC9-silenced or SUMO-silenced crayfish, and the inhibition effect was rescued by injection of recombinant SUMO or UBC9. The results of this study demonstrate that viral IE proteins can be modified by crayfish SUMOylation, prompt the expression of viral genes, and ultimately benefit WSSV replication. Understanding of the mechanisms by which viruses exploit host components will greatly improve our knowledge of the virus-host "arms race" and contribute to the development of novel methods against virulent viruses.

  12. The Juvenile Justice System of the Future.

    ERIC Educational Resources Information Center

    Gladstone, William

    1995-01-01

    A former juvenile and family court judge reflects on experiences with juvenile issues, calling for critical changes in juvenile case handling. Advocates many changes for juvenile and family courts of the future, such as a new type of due process for children and the abolishment of labels such as "delinquent," runaway," or "abandoned" in favor of…

  13. Miranda Rights: Implications for Juveniles with Disabilities

    ERIC Educational Resources Information Center

    Katsiyannis, Antonis; Barrett, David E.; Losinski, Mickey L.

    2011-01-01

    Juvenile delinquency in the United States has been a persistent concern for decades. Consequently, because more juveniles have been referred to juvenile court and the arrest rate of preteen offenders has increased to almost three times that of older youth, the persistent and often controversial issue of the capacity of juvenile offenders to waive…

  14. Ecotoxicological assessment of the impact of nitrate (NO(3)(¯)) on the European endangered white-clawed crayfish Austropotamobius italicus (Faxon).

    PubMed

    Benítez-Mora, Alfonso; Aguirre-Sierra, Arantxa; Alonso, Alvaro; Camargo, Julio A

    2014-03-01

    Field studies and laboratory experiments were conducted to assess the impact of elevated nitrate (NO(3)(¯)) concentrations on the European endangered white-clawed crayfish Austropotamobius italicus (Faxon) in the Henares River Basin (Central Spain), within an area that is vulnerable to nitrate pollution. Two sampling surveys were carried out in the summer of 2009 and 2011 to collect freshwater crayfish at eight sampling sites along this vulnerable area. The invasive read-swamp crayfish Procambarus clarkii (Girard) was the only collected crayfish species. Nitrate toxicity experiments however showed that A. italicus is one of the most tolerant species to nitrate toxicity. Although the food consumption was the most sensitive endpoint to nitrate toxicity (followed by the escape response and mortality), the no-observed-effect concentration (NOEC) for this endpoint after 14 days of exposure to nitrate was as high as 100mg NO(3)(¯)N/l, with some crayfish being still alive after fourteen days of exposure to a nominal nitrate concentration of 800mg NO(3)(-)N/l. Besides, a safe concentration of nitrate for A. italicus, along with its respective 95% confidence limits, were estimated to be 68.5 (22.4-187) mg (NO(3)(¯)N/l. Overall we conclude that elevated nitrate concentrations would not be responsible for the absence of white-clawed crayfish in the Henares River Basin. Other environmental factors, particularly the presence of P. clarkii and its fungal pathogen, would be major causes.

  15. Prolonged time course of glutamate-operated single channel currents in neuromuscular preparations of small crayfish and a membrane current triggered by glutamate channel gating.

    PubMed

    Finger, W; Martin, C; Pareto, A

    1988-08-31

    Single channel currents activated by glutamate were recorded by means of the patch-clamp technique in the abdominal superficial extensor muscle and the claw opener muscle of small (1-3 months old) and large (greater than 16 months old) crayfish. It was found that in small crayfish the time course of glutamate-operated single channel currents was prolonged by a factor of about 4 in these two preparations. In the abdominal superficial extensor muscle, single channel currents activated by 5 mmol/l glutamate had a mean burst length of tau = 2-3 ms in large crayfish and a mean burst length of tau = 8-9 ms in small crayfish. In the claw opener, for large crayfish tau congruent to 0.5 ms and for small crayfish tau = 1.5-2.5 ms resulted (500 mumol/l glutamate). Moreover, single channel currents with long time courses often slowly increased their amplitudes during the open time of the channel and current amplitudes did not decline completely to the baseline after channel closing. In addition, single channel currents with relatively constant amplitude were often followed by a small increasing and decreasing membrane current. The latter results suggest that glutamate channel gating might trigger a membrane current.

  16. Juvenile nasopharyngeal angiofibroma

    PubMed Central

    Makhasana, Jashika Adil Shroff; Kulkarni, Meena A; Vaze, Suhas; Shroff, Adil Sarosh

    2016-01-01

    Juvenile nasopharyngeal angiofibroma (JNA) is a rare benign tumor arising predominantly in the nasopharynx of adolescent males. It is an aggressive neoplasm and shows a propensity for destructive local spread often extending to the base of the skull and into the cranium. Clinically, however, it is obscure with painless, progressive unilateral nasal obstruction being the common presenting symptom with or without epistaxis and rhinorrhea. Diagnosis of JNA is made by complete history, clinical examination, radiography, nasal endoscopy and by using specialized imaging techniques such as arteriography, computer tomography and magnetic resonance imaging. Histopathology reveals a fibrocellular stroma with spindle cells and haphazard arrangement of collagen interspersed with an irregular vascular pattern. A case report of JNA with rare intra-oral manifestation in a 17-year-old male patient is presented in the article. JNA being an aggressive tumor may recur posttreatment. Thus, early diagnosis, accurate staging, and adequate treatment are essential in the management of this lesion.

  17. [JUVENILE DERMATOMYOSITIS AND CALCINOSIS].

    PubMed

    Zhvania, M

    2015-01-01

    Juvenile Dermatomiositis (JD) is autoimmune disease that progresses with time; JD's main differentiated syndromes are rash on the skin, poor function of muscles, and often developing invalidism. If the health practitioners manage to diagnose the JD on an early stage and prescribe the adequate treatment the disease will not progress aggressively. This approach is tangible for practical rheumatology and pediatric. The article aims to present the reasons of the development of the JD and calcinosis. The study based on the description of the patients with JD. There are distinguished the main symptoms of the disease in children: frequent and acute developments of muscles calcinosis, occasionally with diffuse character followed with hypotrophy of the muscles, contractures and invalidism. One of the patient cases that describe the article is the thirteen-year boy with JD indicating repeated sequence of the disease, with diffusive calcinosis, cellulitis followed with secondary infection and impaired vision.

  18. Juvenile idiopathic arthritis.

    PubMed

    Espinosa, Maria; Gottlieb, Beth S

    2012-07-01

    Juvenile idiopathic arthrithis (JIA) is the most common rheumatic disease of childhood.JIA is a chronic disease that is associated with periods of disease flares and periods of disease inactivity.Early, aggressive treatment with nonsteroidal anti-inflammatory drugs, intra-articular corticosteroid injections, or methotrexate, has significantly improved the outcome of most children who have JIA. Biologics have been shown to be both safe and effective for the treatment of more aggressive forms of arthritis and for uveitis. Long-term safety data of biologics is still uncertain. In the near future, it is hoped that genetic testing will allow earlier diagnosis of JIA as well as help predict the disease course of children who have JIA. Genetic analysis also may allow physicians to target therapies more effectively. It is hoped that development of more specific therapies will decrease overall immunosuppression and other associated toxicities.

  19. Juvenile nasopharyngeal angiofibroma

    PubMed Central

    Makhasana, Jashika Adil Shroff; Kulkarni, Meena A; Vaze, Suhas; Shroff, Adil Sarosh

    2016-01-01

    Juvenile nasopharyngeal angiofibroma (JNA) is a rare benign tumor arising predominantly in the nasopharynx of adolescent males. It is an aggressive neoplasm and shows a propensity for destructive local spread often extending to the base of the skull and into the cranium. Clinically, however, it is obscure with painless, progressive unilateral nasal obstruction being the common presenting symptom with or without epistaxis and rhinorrhea. Diagnosis of JNA is made by complete history, clinical examination, radiography, nasal endoscopy and by using specialized imaging techniques such as arteriography, computer tomography and magnetic resonance imaging. Histopathology reveals a fibrocellular stroma with spindle cells and haphazard arrangement of collagen interspersed with an irregular vascular pattern. A case report of JNA with rare intra-oral manifestation in a 17-year-old male patient is presented in the article. JNA being an aggressive tumor may recur posttreatment. Thus, early diagnosis, accurate staging, and adequate treatment are essential in the management of this lesion. PMID:27601836

  20. Juvenile nasopharyngeal angiofibroma.

    PubMed

    Makhasana, Jashika Adil Shroff; Kulkarni, Meena A; Vaze, Suhas; Shroff, Adil Sarosh

    2016-01-01

    Juvenile nasopharyngeal angiofibroma (JNA) is a rare benign tumor arising predominantly in the nasopharynx of adolescent males. It is an aggressive neoplasm and shows a propensity for destructive local spread often extending to the base of the skull and into the cranium. Clinically, however, it is obscure with painless, progressive unilateral nasal obstruction being the common presenting symptom with or without epistaxis and rhinorrhea. Diagnosis of JNA is made by complete history, clinical examination, radiography, nasal endoscopy and by using specialized imaging techniques such as arteriography, computer tomography and magnetic resonance imaging. Histopathology reveals a fibrocellular stroma with spindle cells and haphazard arrangement of collagen interspersed with an irregular vascular pattern. A case report of JNA with rare intra-oral manifestation in a 17-year-old male patient is presented in the article. JNA being an aggressive tumor may recur posttreatment. Thus, early diagnosis, accurate staging, and adequate treatment are essential in the management of this lesion. PMID:27601836

  1. Juvenile homosexual homicide.

    PubMed

    Myers, Wade C; Chan, Heng Choon Oliver

    2012-01-01

    Limited information exists on juvenile homosexual homicide (JHH), that is, youths who perpetrate sexual homicides against same-sex victims. Only a handful of cases from the United States and internationally have been described in the literature. This study, the first of its kind, examines the epidemiology, victimology, victim-offender relationship, and weapon-use patterns in JHH offenders using a large U.S. database on homicide spanning three decades. The data for this study were derived from the Federal Bureau of Investigation's Supplementary Homicide Reports (SHRs) for the years 1976 through 2005. A total of 93 cases of JHH were identified. On average, three of these crimes occurred annually in the U.S., and there was a marked decline in its incidence over the study period. Ninety-five percent were male offender-male victim cases and 5% were female offender-female victim cases. JHH offenders were over-represented amongst all juvenile sexual murderers, similar to their adult counterparts. The majority of these boys were aged 16 or 17 and killed adult victims. They were significantly more likely to kill adult victims than other age groups, to be friends or acquaintances of the victims, and to use contact/edged weapons or firearms. Most offenders killed same-race victims, although Black offenders were significantly more likely than White offenders to kill interracially. A case report is provided to illustrate JHH. Further research is needed to promote our understanding of the pathogenesis, etiology, and associated risk factors for this aberrant form of murder by children.

  2. Transfer of Juvenile Cases to Criminal Court.

    PubMed

    Lee, Soo Jung; Kraus, Louis J

    2016-01-01

    The first juvenile court was founded in 1899 with the focus on rehabilitation of a juvenile offender as opposed to punishment in adult court. Determining culpability and disposition for adolescents has become a source of much discussion. With serious crimes, juvenile delinquents may be transferred from juvenile court to adult criminal court; this practice became more prevalent in the past century. However, growing knowledge of adolescent development has mitigated the culpability of youth offenders and resulted in judicial decisions influential to juvenile dispositions.

  3. A screening-level assessment of lead, cadmium, and zinc in fish and crayfish from northeastern Oklahoma, USA

    USGS Publications Warehouse

    Schmitt, C.J.; Brumbaugh, W.G.; Linder, G.L.; Hinck, J.E.

    2006-01-01

    The objective of this study was to evaluate potential human and ecological risks associated with metals in fish and crayfish from mining in the Tri-States Mining District (TSMD). Crayfish (Orconectes spp.) and fish of six frequently consumed species (common carp, Cyprinus carpio; channel catfish, Ictalurus punctatus; flathead catfish, Pylodictis olivaris; largemouth bass, Micropterus salmoides; spotted bass, M. punctulatus; and white crappie, Pomoxis annularis) were collected in 2001-2002 from the Oklahoma waters of the Spring River (SR) and Neosho River (NR), which drain the TSMD. Samples from a mining-contaminated site in eastern Missouri and from reference sites were also analyzed. Individual fish were prepared for human consumption in the manner used locally by Native Americans (headed, eviscerated, and scaled) and analyzed for lead, cadmium, and zinc. Whole crayfish were analyzed as composite samples of 5-60 animals. Metals concentrations were typically higher in samples from sites most heavily affected by mining and lowest in reference samples. Within the TSMD, most metals concentrations were higher at sites on the SR than on the NR and were typically highest in common carp and crayfish than in other taxa. Higher concentrations and greater risk were associated with fish and crayfish from heavily contaminated SR tributaries than the SR or NR mainstems. Based on the results of this and previous studies, the human consumption of carp and crayfish could be restricted based on current criteria for lead, cadmium, and zinc, and the consumption of channel catfish could be restricted due to lead. Metals concentrations were uniformly low in Micropterus spp. and crappie and would not warrant restriction, however. Some risk to carnivorous avian wildlife from lead and zinc in TSMD fish and invertebrates was also indicated, as was risk to the fish themselves. Overall, the wildlife assessment is consistent with previously reported biological effects attributed to metals

  4. Noise-assisted information transfer in crayfish mechanoreceptors: stochastic resonance in a neuronal receptor

    NASA Astrophysics Data System (ADS)

    Douglass, John K.; Wilkens, Lon A.; Moss, Frank

    1993-11-01

    Adding random noise to a weak periodic signal can enhance the flow of information through certain nonlinear physical systems, via a process known as stochastic resonance (SR). We have used crayfish mechanoreceptor cells to investigate the possibility that SR can be induced in neurophysiological systems. Various signal-to-noise ratio (SNR) measurements were derived from the action potentials (spikes) of single receptor cells stimulated with weak periodic signals. Spike noise was controlled by one of two methods: (1) adding external noise to the stimulus, or (2) altering internal noise sources by changing the temperature of the cell. In external noise experiments, an optimal noise level can be identified at which the SNR is maximized. In internal noise experiments, although the SNR increases with increasing noise, no SNR maximum has been observed. These results demonstrate that SR can be induced in single neurons, and suggest that neuronal systems may also be capable of exploiting SR.

  5. Noise enhancement of information transfer in crayfish mechanoreceptors by stochastic resonance

    NASA Astrophysics Data System (ADS)

    Douglass, John K.; Wilkens, Lon; Pantazelou, Eleni; Moss, Frank

    1993-09-01

    IN linear information theory, electrical engineering and neurobiology, random noise has traditionally been viewed as a detriment to information transmission. Stochastic resonance (SR) is a nonlinear, statistical dynamics whereby information flow in a multistate system is enhanced by the presence of optimized, random noise1 4. A major consequence of SR for signal reception is that it makes possible substantial improvements in the detection of weak periodic signals. Although SR has recently been demonstrated in several artificial physical systems5,6, it may also occur naturally, and an intriguing possibility is that biological systems have evolved the capability to exploit SR by optimizing endogenous sources of noise. Sensory systems are an obvious place to look for SR, as they excel at detecting weak signals in a noisy environment. Here we demonstrate SR using external noise applied to crayfish mechanoreceptor cells. Our results show that individual neurons can provide a physiological substrate for SR in sensory systems.

  6. Dual and opposing modulatory effects of serotonin on crayfish lateral giant escape command neurons.

    PubMed

    Teshiba, T; Shamsian, A; Yashar, B; Yeh, S R; Edwards, D H; Krasne, F B

    2001-06-15

    Serotonin modulates afferent synaptic transmission to the lateral giant neurons of crayfish, which are command neurons for escape behavior. Low concentrations, or high concentrations reached gradually, are facilitatory, whereas high concentrations reached rapidly are inhibitory. The modulatory effects rapidly reverse after brief periods of application, whereas longer periods of application are followed by facilitation that persists for hours. These effects of serotonin can be reproduced by models that involve multiple interacting intracellular signaling systems that are each stimulated by serotonin. The dependence of the neuromodulatory effect on dose, rate, and duration of modulator application may be relevant to understanding the effects of natural neuromodulation on behavior and cognition and to the design of drug therapies. PMID:11404440

  7. Editor's Shelf: International Juvenile Titles.

    ERIC Educational Resources Information Center

    Mitchell-Powell, Brenda

    1994-01-01

    Provides an annotated list of international juvenile picture books and notes those that emphasize text over pictures. The 49 titles present international perspectives for educators, librarians, and parents seeking materials with alternative cultural content. The majority are folk tales. (SLD)

  8. Effects of Deltamethrin on crayfish motor axon activity and neuromuscular transmission.

    PubMed

    Meng, Linlin; Meyer, Pierre-Francois N R; Leary, Meghan L; Mohammed, Yussef F; Ferber, Shelbi D; Lin, Jen-Wei

    2016-03-23

    Deltamethrin (DM) is a widely used pesticide known to target sodium channels. Although this compound has been studied extensively at molecular and behavioral levels, the detailed action of DM on cellular and synaptic function is less well documented. In this report, we show that DM at nanomolar concentrations can silence tonic motor output of the crayfish ventral superficial flexor (VSF) within ∼10 min. Action potential (AP) amplitude was consistently reduced before silencing occurred, whereas AP duration and AP firing frequency did not change. In some synapses EPSP amplitude and synaptic delay were modified by DM, but the direction of change was not consistent. In order to better understand these diverse effects, intracellular recordings from motor axons of the crayfish opener were used for a detailed analysis. DM caused an initial, slow depolarization of resting membrane potential (Vm), which was accompanied by reduced AP amplitude but not AP duration. Resting Vm then underwent a step depolarization of ∼20 mV, which we propose corresponds to the onset of the depolarization block. In addition, DM shifted the AP initiation site in some opener axons during prolonged firing. This shift occurred concomitantly with a reduction in synaptic delay. A similar reduction in synaptic delay was also detected at some VSF axons, and can be attributed to the same mechanism. Results reported here suggest that DM at low concentrations result in: (i) depolarization block of motor axons before changes in network output can be detected, (ii) variable effects on synaptic transmission, with this variability presumably due to the diverse morphology and excitability of motor axons. PMID:26861201

  9. Freshwater Crayfish: A Potential Benthic-Zone Indicator of Nanosilver and Ionic Silver Pollution.

    PubMed

    Brittle, Seth W; Paluri, Sesha L A; Foose, Daniel P; Ruis, Matthew T; Amato, Matthew T; Lam, Nhi H; Buttigieg, Bryan; Gagnon, Zofia E; Sizemore, Ioana E

    2016-07-01

    Nowadays, silver nanoparticles (AgNPs) are utilized in numerous applications, raising justified concerns about their release into the environment. This study demonstrates the potential to use freshwater crayfish as a benthic-zone indicator of nanosilver and ionic silver pollution. Crayfish were acclimated to 20 L aquaria filled with Hudson River water (HRW) and exposed for 14 days to widely used Creighton AgNPs and Ag(+) at doses of up to 360 μg L(-1) to surpass regulated water concentrations. The uptake and distribution of Ag in over 650 exoskeletons, gills, hepatopancreas and muscles samples were determined by inductively coupled plasma optical emission spectroscopy (ICP-OES) in conjunction with two complementary U.S. EPA-endorsed methods: the external calibration and the standard additions. Reflecting the environmental plasticity of the two investigated species, Orconectes virilis accumulated in a dose-dependent manner more Ag than Procambarus clarkii (on average 31% more Ag). Both species showed DNA damage and severe histological changes in the presence of Ag. However, Ag(+) generally led to higher Ag accumulations (28%) and was more toxic. By the harvest day, about 14 ± 9% of the 360 μg L(-1) of AgNP exposure in the HRW oxidized to Ag(+) and may have contributed to the observed toxicities and bioaccumulations. The hepatopancreas (1.5-17.4 μg of Ag g(-1) of tissue) was identified as the best tissue-indicator of AgNP pollution, while the gills (4.5-22.0 μg g(-1)) and hepatopancreas (2.5-16.7 μg g(-1)) complementarily monitored the presence of Ag(+). PMID:27253383

  10. A giant juvenile nasopharyngeal angiofibroma.

    PubMed

    Yüce, Salim; Uysal, Ismail Önder; Doğan, Mansur; Polat, Kerem; Salk, Ismail; Müderris, Suphi

    2013-05-01

    Juvenile nasopharyngeal angiofibromas are locally growing and highly vascular tumors. They are primarily treated through surgical excision ranging from an open approach to an endoscopic approach. We presented a 20-year-old man with a giant juvenile nasopharyngeal angiofibroma that bilaterally obliterated the pterygopalatine fossa, invaded the sphenoid bone, and extended to the left nasal passage. His complaints were epistaxis and nasal obstruction. After embolization, the patient was treated surgically using the endoscopic approach and declared cured and discharged without any complications.

  11. A Giant Juvenile Nasopharyngeal Angiofibroma

    PubMed Central

    Yüce, Salim; Uysal, İsmail Önder; Doğan, Mansur; Polat, Kerem; Şalk, İsmail; Müderris, Suphi

    2012-01-01

    Juvenile nasopharyngeal angiofibroma (JNA) are locally growing highly vascular tumours. They are treated primarily by surgical excision ranging from open approach to endoscopic approach. We presented a 20-year-old male with a giant nasopharyngeal juvenile angiofibroma obliterating the pterygopalatine fossa bilaterally, invasing the sphenoid bone and extending to the left nasal passage. His complaints were epistaxis and nasal obstruction. After embolization, the patient was treated surgically with endoscopic approach and discharged as cured without any complication. PMID:23714961

  12. Juvenile xanthogranuloma with lichenoid appearance.

    PubMed

    Yoneda, Kozo; Demitsu, Toshio; Kubota, Yasuo

    2012-05-01

    Juvenile xanthogranulomas are benign histiocytic cell tumors that develop mainly in infancy and early childhood and then spontaneously regress. We report a 2-year-old boy who presented with generalized eruption of a mixture of micronodular and macronodular juvenile xanthogranuloma with a large number of widely distributed lichenoid papules. Light microscopic and immunocytochemical analyses of the lesion were consistent with juvenile xanthogranuloma. Abdominal ultrasonography did not detect any visceral lesions, and brain magnetic resonance imaging did not detect any mass lesions. We decided to observe the course without treatment in this case because there are no internal masses of juvenile xanthogranuloma. Regular follow up has therefore been scheduled. To our knowledge, this is the third report of a case demonstrating juvenile xanthogranuloma with lichenoid appearance. Future analyses of various cytokines such as granulocyte-macrophage colony-stimulating factor and/or tumor necrosis factor-α in juvenile xanthogranuloma lesions should be of great help in elucidating the pathogenesis of this disease. PMID:21980990

  13. Granulocytes of the red claw crayfish Cherax quadricarinatus can endocytose beads, E. coli and WSSV, but in different ways.

    PubMed

    Duan, Hu; Jin, Songjun; Zhang, Yan; Li, Fuhua; Xiang, Jianhai

    2014-10-01

    The hemocytes of the red claw crayfish Cherax quadricarinatus are classified by morphologic observation into the following types: hyalinocytes (H), semi-granulocytes (SG) and granulocytes (G). Density gradient centrifugation with Percoll was developed to separate these three subpopulations of hemocytes. Beads, Escherichia coli, and FITC labeling WSSV were used to investigate the characteristics of granulocytes by using scanning electron microscope, transmission electron microscope, and laser scan confocal microscope. Results showed that granulocytes could phagocytose beads and E. coli by endocytic pathways. WSSV could rely on caveolae-mediated endocytosis to mainly enter into granulocytes. These results could elucidate the mechanism of the innate immunity function of granulocytes, and it also showed the mechanism by which WSSV invaded granulocytes in the red claw crayfish.

  14. Determination of heavy metals in crayfish by ICP-MS with a microwave-assisted digestion treatment.

    PubMed

    López, F J Sánchez; Garcia, M D Gil; Morito, N P Sánchez; Vidal, J L Martínez

    2003-02-01

    Contamination of the American red crayfish, from the Guadiamar riverside, is due to the disastrous toxic spill that occurred on 25 April 1998 in the mining area of Aznalcóllar-Los Frailes, Spain. A high concentration of heavy metals in the waters from the mine pool and their spill to the river Guadiamar was the cause of the destruction of a great number of animal and vegetable organisms. An ICP-MS method for the total determination of heavy metals (Cu, Zn, Pb, and Cd) in whole bodies of American red crayfish (Procambarus clarkii) was used. Metals were extracted from the matrix in a closed-vessel microwave digestion system with nitric acid and hydrogen peroxide. A study of the uncertainty of the method for the determination of metals was carried out; at a concentration of 5 microg/L, the uncertainty was below 34%. PMID:12550101

  15. Real-time monitoring of water quality using fish and crayfish as bio-indicators: a review.

    PubMed

    Kuklina, Iryna; Kouba, Antonín; Kozák, Pavel

    2013-06-01

    Water quality monitoring using fish and crayfish as bio-indicators requires an understanding of the state of pollution of waters, choice of bio-indicators, physiological and behavioral endpoints of fish and crayfish, and principles of the methodology and their potential applications. Here, we discuss telemetry, acoustic monitoring, vision-based monitoring, measures of ventilatory activity, electrocardiography, and fiber-optic plethysmography. Assessment of water quality must be based, not only on physicochemical characteristics of the current environment as determined by chemical analyses, but also on observations of the physiology and behavior of its inhabitants. Real-time biomonitoring is suggested as the most reliable method, since it incorporates living organisms into the system to serve as biosensors. The potential application of the methods discussed includes use at water treatment plants and water supply stations for prevention of hazardous toxicological events, and, for aquaculture, in ponds, lakes, and aquariums for monitoring growth, population size, and behavior traits. PMID:23054288

  16. Juvenile temporal arteritis revisited.

    PubMed

    Tomlinson, F H; Lie, J T; Nienhuis, B J; Konzen, K M; Groover, R V

    1994-05-01

    We describe a case of arteritis involving the superficial temporal artery in an 8-year-old boy. After a 2-week prodrome of headache in the right temporal region, a painful pulsatile 6-mm nodule developed. No history of trauma or systemic disease was noted. The differential diagnosis included vasculitis or thrombosis of a vascular malformation of the temporal artery. The lesion was surgically excised for both diagnostic and cosmetic reasons. Histologic features of the nodule were diagnostic of juvenile temporal arteritis and characterized by non-giant cell granulomatous inflammation of the temporal artery, occlusive fibrous intimal proliferation, and microaneurysmal disruption of the media. At 12-month follow-up, the patient was well; no recurrent lesions or systemic disease was noted. Although rare, this disease should be recognized as arteritis that affects the external carotid circulation and should not be confused with classic giant cell temporal arteritis. If physicians are aware of this benign inflammatory disease of the temporal artery in children and young adults, unnecessary treatment will not be administered.

  17. Imaging for juvenile angiofibroma.

    PubMed

    Lloyd, G; Howard, D; Lund, V J; Savy, L

    2000-09-01

    Juvenile angiofibroma presents characteristic imaging signs, may of which allow diagnosis and accurate estimation of extent without recourse to the dangers of biopsy. The diagnosis by computed tomography (CT) is based upon the site of origin of the lesion in the pterygopalatine fossa. There are two constant features: (1) a mass in the posterior nasal cavity and pterygopalatine fossa; (2) erosion of bone behind the sphenopalatine foramen with extension to the upper medial pterygoid plate. Good bone imaging on CT is essential to show invasion of the cancellous bone of the sphenoid. This is the main predictor of recurrence: the deeper the extension, the larger the potential tumour remnant likely to be left following surgery. The characteristic features on magnetic resonance imaging (MRI) are due to the high vascularity of the tumour causing signal voids and strong post-contrast enhancement. MRI shows the pre-operative soft tissue extent of angiofibroma optimally, but its more important application is to provide post-operative surveillance: to show any residual or recurrent tumour, record tumour growth or natural involution and monitor the effects of radiotherapy.

  18. Managing juvenile Huntington's disease.

    PubMed

    Quarrell, Oliver W J; Nance, Martha A; Nopoulos, Peggy; Paulsen, Jane S; Smith, Jonathan A; Squitieri, Ferdinando

    2013-06-01

    Huntington's disease (HD) is a well-recognized progressive neurodegenerative disorder that follows an autosomal dominant pattern of inheritance. Onset is insidious and can occur at almost any age, but most commonly the diagnosis is made between the ages of 35 and 55 years. Onset ≤20 years of age is classified as juvenile HD (JHD). This age-based definition is arbitrary but remains convenient. There is overlap between the clinical pathological and genetic features seen in JHD and more traditional adult-onset HD. Nonetheless, the frequent predominance of bradykinesia and dystonia early in the course of the illness, more frequent occurrence of epilepsy and myoclonus, more widespread pathology, and larger genetic lesion means that the distinction is still relevant. In addition, the relative rarity of JHD means that the clinician managing the patient is often doing so for the first time. Management is, at best, symptomatic and supportive with few or no evidence-based guidelines. In this article, the authors will review what is known of the condition and present some suggestions based on their experience. PMID:24416077

  19. The power of next-generation sequencing as illustrated by the neuropeptidome of the crayfish Procambarus clarkii.

    PubMed

    Veenstra, Jan A

    2015-12-01

    Transcriptomes of the crayfish Procambarus clarkii were analyzed for the presence of transcripts encoding neurohormones, neuropeptides and their receptors. A total of 58 different transcripts were found to encode such ligands and another 82 for their receptors. A very large number of the neuropeptide transcripts appeared to be complete and for those that were not only small parts seemed to be lacking. Transcripts for the neuropeptide GPCRs as well as for the putative receptors for insulin, neuroparsin and eclosion hormone were often also complete or almost so. Of particular interest is the presence of three different neuroparsin genes and two putative neuroparsin receptors. There are also three pigment dispersing hormones as well three likely receptors for these neuropeptides. CNMamide, calcitonin, CCRFamide, natalisin, trissin and relaxin appear to be new crustacean neuropeptides. The recently identified crustacean female sex hormone was also found and in the crayfish appears to be not only expressed in the eyestalk, but in the ovary as well (though not in the testis). Interestingly, there are two other proteins in the crayfish with a structure similar to crustacean female sex hormone, that could be precursors of neurohormones, but these are not expressed by the ovary. The ovary also appears to contain significant numbers of transcripts encoding pigment dispersing hormones, CNMamide as well as glycoprotein B5, but not glycoprotein A2.

  20. Drug-seeking behavior in an invertebrate system: evidence of morphine-induced reward, extinction and reinstatement in crayfish.

    PubMed

    Nathaniel, Thomas I; Panksepp, Jaak; Huber, Robert

    2009-02-11

    Several lines of evidence suggest that exploring the neurochemical basis of reward in invertebrate species may provide clues for the fundamental behavioral and neurobiology underpinnings of drug addiction. How the presence of drug-sensitive reward relates to a decrease in drug-seeking behavior and reinstatement of drug-seeking behavior in invertebrate systems is not known. The present study of a conditioned place preference (CPP) paradigm in crayfish (Orconectes rusticus) explores morphine-induced reward, extinction and reinstatement. Repeated intra-circulatory infusions of 2.5 microg/g, 5.0 microg/g and 10.0 microg/g doses of morphine over 5 days serve as a reward when paired with a distinct visual or tactile environment. Morphine-induced CPP was extinguished after repeated saline injections for 5 days in the previously morphine-paired compartment. After the previously established CPP had been eliminated during the extinction phase, morphine-experienced crayfish were challenged with 2.5 microg/g, 5.0 microg/g and 10.0 microg/g, respectively. The priming injections of morphine reinstated CPP in all training doses, suggesting that morphine-induced CPP is unrelenting, and that with time, it can be reinstated by morphine following extinction in an invertebrate model just like in mammals. Together with other recent studies, this work demonstrates the advantage of using crayfish as an invertebrate animal model to investigate the basic biological processes that underline exposure to mammalian drugs of abuse.

  1. Effect of alkaline treatment ('akanwu') and supplementary value of corn or crayfish on the protein quality of breadfruit (Treculia Africana).

    PubMed

    Nzomiwu, N R

    1990-04-01

    The effect of treatment and supplementary value of corn (C) or crayfish (CR) on the protein quality of breadfruit (Treculia Africana) flours were studied in eighteen young rats. The 70:30 or 70:15:15 (Protein basis) combinations of breadfruit flours and corn or crayfish or both provided 1.6 g N/100 g diet for the 35 day study. The addition of 'akanwu' to the cooking water reduced cooking time and crude protein and saved fuel. The addition of 'akanwu' and replacement of CR with C was not beneficial as judged by the parameters tested except for the wt. gain and PER. On the other hand, when crayfish was the only source of supplementary protein (30%) to breadfruit cooked without 'akanwu' there were increases in all parameters tested over those with added 'akanwu' except for the N intake, wt. gain, and PER. These results appear to suggest that addition of 'akanwu' to TA was detrimental to its protein utilization and that TA appears to be an economic source of N in areas where it is a staple. Based on the results of this study, one would suggest that the use of 'akanwu' as a tenderizer should be seriously looked into before further use.

  2. Forensic aspects of juvenile violence.

    PubMed

    Haller, L H

    2000-10-01

    The juvenile justice system was created because it was recognized that youthful offenders needed to be managed differently from adults. They were to receive habilitation services instead of punishment. It is now more than a century since the creation of the first juvenile court. After 67 years, the US Supreme Court, in Kent v United States stated that the model was not working because juveniles in the criminal justice system received no treatment and they had no rights. Because the issue that had been appealed was the lack of rights (not lack of treatment), the Court mandated that juveniles, like adults, be given certain rights. The following year, in In re Gault, the Court expanded these rights. Subsequent Supreme Court cases have dealt with these kinds of issues--that is, whether juvenile offenders are entitled to the same rights as adults and subject to the same penalties. The Supreme Court has never heard a "right to treatment" case, which is the other part of the juvenile court system. Cases have been brought in lower courts (e.g., Nelson v. Heyne, 1972) alleging inadequate treatment services, but no national impact has resulted. Thus, in general, children in the juvenile court system do not have an enforceable right to treatment and can obtain only what services are available in their jurisdictions. The services often are woefully inadequate. Sentencing a youth to probation, with the requirement that he or she participate in counseling or mental health treatment, is meaningless if services are not available. Community-based, model programs that provide effective treatment do exist. They are, as yet, the rare exception rather than the norm and, therefore, are not available to most youthful offenders. Incarcerated juveniles, obviously, cannot avail themselves of community programs. Litigation to give these youth the same rights as adults in penal institutions is not the answer because incarcerated adults don't have a right to treatment, only a right to be free

  3. Integration of an invasive consumer into an estuarine food web: direct and indirect effects of the New Zealand mud snail.

    PubMed

    Brenneis, Valance E F; Sih, Andrew; de Rivera, Catherine E

    2011-09-01

    Introduced species interact both directly and indirectly with native species. We examine interactions between the introduced New Zealand mud snail (Potamopyrgus antipodarum) and native estuarine invertebrates and predators through experiments and field studies. A widely held management concern is that when P. antipodarum, which has low nutritional value, becomes abundant, it replaces nutritious prey in fish diets. We tested two key components of this view: (1) that fish consume, but get little direct nutritional value from P. antipodarum; and (2) that P. antipodarum has an indirect negative effect on fish by reducing the energy derived from native prey. We also examined predation by the native signal crayfish, Pacifastacus leniusculus. Laboratory feeding trials showed that both crayfish and fish consume P. antipodarum, a direct effect. Crayfish consumed and successfully digested higher numbers of snails than did fish [Pacific staghorn sculpin (Leptocottus armatus), three spine stickleback (Gasterosteus aculeatus), and juvenile starry flounder (Platicthys stellatus)]. P. antipodarum occurred at low frequencies in the stomachs of wild-caught fish. More interesting were the indirect effects of this invader, which ran counter to predictions. P. antipodarum presence was associated with no change or an increase in the amount of energy derived from native prey by predators. The presence of P. antipodarum also led to increased consumption of and preference for the native amphipod Americorophium salmonis over the native isopod Gnorimosphaeroma insulare. This is an example of short-term, asymmetric, apparent competition, in which the presence of one prey species (snails) increases predation on another prey species (the amphipod).

  4. The Heterogeneity of Juvenile Myositis

    PubMed Central

    Rider, Lisa G.

    2007-01-01

    Juvenile myositis is a heterogeneous group of systemic autoimmune diseases, in which clinical and serologic subgroups result in subsets of patients with distinct clinical manifestations, disease courses, immunogenetic associations, responses to therapy, and prognoses. A newly identified autoantibody of unknown specificity, anti-p155, is myositis-associated and seen in up to 20 – 30% of juvenile and adult DM patients. HLA DRB1*0301 and its linked allele DQA1*0501 have been identified as the major immunogenetic risk factor for juvenile and adult DM in both European- and African- American patients, and DQA1*0301 is an additional risk factor in European American patients. Several DQA1 alleles also are protective for juvenile DM. Environmental risk factors are poorly understood, but growing evidence suggests a role for infectious agents and ultraviolet radiation. The current therapy of juvenile DM consists of corticosteroids and other immunosuppressive agents, with the adjunctive treatment of cutaneous manifestations and rehabilitation. Therapeutic trials of biologic agents, including anti-TNFα and anti-CD20, may aid in developing promising new therapies for these disorders. PMID:17317616

  5. Genetics Home Reference: juvenile Paget disease

    MedlinePlus

    ... juvenile Paget disease: Genetic Testing Registry: Hyperphosphatasemia with bone disease These resources from MedlinePlus offer information about the ... familial osteoectasia hyperostosis corticalis deformans juvenilis hyperphosphatasemia ... idiopathic idiopathic hyperphosphatasia JPD juvenile Paget's ...

  6. New Treatments Helping Kids with Juvenile Arthritis

    MedlinePlus

    ... 159984.html New Treatments Helping Kids With Juvenile Arthritis Several biologics have been approved by the FDA ... 20, 2016 (HealthDay News) -- New treatments for juvenile arthritis offer hope to children with the chronic autoimmune ...

  7. Characteristics of adopted juvenile delinquents.

    PubMed

    Kim, W J; Zrull, J P; Davenport, C W; Weaver, M

    1992-05-01

    There have been many reports describing the uniqueness of adopted children and adolescents' delinquent behaviors in terms of both their delinquent characteristics and courts' treatment of them. A total of 43 adopted juveniles, 32 extrafamilial (1.0%) and 11 intrafamilial (0.3%) adoptions were initially identified out of 3,280 juvenile delinquents. The adopted subjects were then compared with the demographically matched and offense matched nonadopted subjects. The family variables, such as marital and employment status of parents, were significantly different. However, there were only a few discernible trends, and in general there were no significant differences between the adopted and nonadopted juveniles in terms of their offense characteristics and dispositions. PMID:1592787

  8. Guidelines for Juvenile Information Sharing. OJJDP Report

    ERIC Educational Resources Information Center

    Mankey, Jennifer; Baca, Patricia; Rondenell, Stephanie; Webb, Marilyn; McHugh, Denise

    2006-01-01

    The juvenile information sharing (JIS) guidelines were prepared by the Center for Network Development (CND) for the Office of Juvenile Justice and Delinquency Prevention (OJJDP). The guidelines suggest a course of action for key agency and organization stakeholders involved in a state or local effort to implement and sustain juvenile information…

  9. Disability and Juvenile Delinquency: Issues and Trends

    ERIC Educational Resources Information Center

    Morris, Kimberly A.; Morris, Richard J.

    2006-01-01

    The US juvenile justice system has gone through many changes since its inception in the late 1890s. Even with these changes and more than 100 years of empirical research, there is a paucity of literature published on juvenile delinquents with disabilities. The present article focuses on juvenile delinquents with disabilities, addressing…

  10. Families, Juvenile Justice and Children's Mental Health.

    ERIC Educational Resources Information Center

    McManus, Marilyn C., Ed.

    1997-01-01

    The theme issue of this bulletin is a discussion of youth with emotional disturbances who are in the juvenile justice system and how to meet their needs. Articles include: (1) "Responding to the Mental Health Needs of Youth in the Juvenile Justice System" (Susan Rotenberg); (2) "Prevalence of Mental Disorders among Youth in the Juvenile Justice…

  11. Counseling Juvenile Offenders in Institutional Settings.

    ERIC Educational Resources Information Center

    Chaneles, Sol, Ed.

    1982-01-01

    Reviews several aspects of counseling services for institutionalized juvenile offenders. The six articles include studies on the functional analysis of behavior in detention, vocational and social rehabilitation, the impact of a juvenile awareness program on personality traits, and the effectiveness of a juvenile transition center. (JAC)

  12. On the Prevention of Juvenile Crime

    ERIC Educational Resources Information Center

    Lelekov, V. A.; Kosheleva, E. V.

    2008-01-01

    Crimes committed by juveniles are among the most urgent social problems. Juvenile crime is as prevalent as crime itself is, and it has not been solved completely in any society and cannot be solved through law enforcement measures alone. In this article, the authors discuss the dynamics and structure of juvenile crime in Russia and present data…

  13. Intensive Reading Instruction in Juvenile Correctional Settings

    ERIC Educational Resources Information Center

    Williams, Jacob L.; Wexler, Jade; Roberts, Greg; Carpenter, Clint

    2011-01-01

    Despite 60 years of evidence linking juvenile illiteracy and delinquency, practitioners and policymakers have been painfully slow in the implementation of evidence-based reading interventions for incarcerated juveniles. We will present the Texas Juvenile Justice Tiered Instructional Model, an evidence-based reading program model created…

  14. Reforming Our Expectations about Juvenile Justice

    ERIC Educational Resources Information Center

    Rodriguez, Pamela F.; Baille, Daphne M.

    2010-01-01

    Typing the term "juvenile justice reform" into a Google[TM] search will result in 60 pages of entries. But what is meant by juvenile justice reform? What does it look like? How will one know when it is achieved? This article defines juvenile justice reform, discusses the principles of effective reform, and describes the practice of juvenile…

  15. Prevention of Serious and Violent Juvenile Offending. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Wasserman, Gail A.; Miller, Laurie S.; Cothern, Lynn

    This bulletin explores the proximal risk factors for juvenile offending, reviews the early developmental precursors to violent offending, and summarizes approaches to prevention. It also discusses components of intervention programs, limitations of single-focus prevention, examples of multi systemic interventions, and limitations of prevention…

  16. Special Education and the Juvenile Justice System. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Burrell, Sue; Warboys, Loren

    This bulletin summarizes provisions of federal law as they pertain to special education and juvenile justice. It discusses provisions of the Individuals with Disabilities Education Act 1997 including: the definition of disability; free appropriate public education; identification, referral, and evaluation; the individualized education program…

  17. Mobilizing Communities To Prevent Juvenile Crime. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Bownes, Donna; Ingersoll, Sarah

    Through Title V Incentive Grants for Local Delinquency Prevention Programs (Community Prevention Grants), the Office of Juvenile Justice and Delinquency Prevention (OJJDP) allocated $20 million in fiscal year 1997 to states to complement law enforcement and justice system efforts by helping local communities foster strong families and nurture…

  18. Race as a Factor in Juvenile Arrests. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Pope, Carl E.; Snyder, Howard E.

    This bulletin examines the effect of race on police decisions to take juvenile offenders into custody. Analysis of 1997 and 1998 data on 17 states from the Federal Bureau of Investigation's National Incident-Based Reporting System indicates that there is no evidence to support the hypothesis that police are more likely to arrest nonwhite juvenile…

  19. Bullfrog tadpole (Rana catesbeiana) and red swamp crayfish (Procambarus clarkii) predation on early life stages of endangered razorback sucker (Xyrauchen texanus)

    USGS Publications Warehouse

    Mueller, G.A.; Carpenter, J.; Thornbrugh, D.

    2006-01-01

    Bullfrog tadpoles (Rana catesbeiana) and red swamp crayfish (Procambarus clarkii) are widespread introduced taxa that are problematic throughout the western United States. Their impact on native amphibians and crustaceans is well documented, but less is known regarding their influence on native fishes. Predator-prey tank tests showed both species consumed eggs and larvae of the endangered razorback sucker (Xyrauchen texanus) in a laboratory setting. Tadpoles consumed 2.2 razorback sucker eggs/d and 1.4 razorback sucker larvae/d, while crayfish ate 6.0 eggs/d and 3.5 larvae/d. Relatively high densities of bullfrog tadpoles and crayfish in razorback sucker spawning areas suggest that these nonnative taxa might pose a threat to the recruitment success of this and other imperiled native fish.

  20. Effects of temperature on the acute toxicity of heavy metals (Cr, Cd, and Hg) to the freshwater crayfish, Procambarus clarkii (Girard)

    SciTech Connect

    Del Ramo, J.; Diaz-Mayans, J.; Torreblanca, A.; Nunez, A.

    1987-05-01

    Chromium, an essential trace element for humans and animals is involved in normal carbohydrate metabolism; however, it is toxic at high concentrations. There is no evidence that cadmium and mercury are biologically essential but their toxicity for organisms is well known. Both cause toxic effects at low concentrations to most organisms, especially in combination with other environmental variables such as temperature. Lake Albufera and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic industrial residues (including heavy metals) from the many urban and waste waters in this area. In 1978, the American red crayfish Procambarus clarkii appeared in lake Albufera and in the surrounding rice fields. Without adequate sanitary control, the crayfish is presently being fished commercially for human consumption. The purpose of the present study is to evaluate the degree of toxicity of various heavy metals (chromium, cadmium and mercury) to freshwater crayfish Procambarus clarkii at various temperatures.

  1. Oregon's Juvenile Psychiatric Security Review Board.

    PubMed

    Newman, Stewart S; Buckley, Mary Claire; Newman, Senia Pickering; Bloom, Joseph D

    2007-01-01

    In 2005, the Oregon Legislature passed a bill modifying the existing Psychiatric Security Review Board (PRSB) statute, creating a juvenile panel for management of juvenile insanity acquittees. Dubbed the Juvenile PSRB (JPSRB), it borrows heavily from the 30 years of experience of its adult predecessor. Statutory language was also modified to create a plea of "responsible except for insanity" for juveniles in Oregon. The authors discuss the similarities of the JPSRB to the adult PSRB system and highlight the differences that take into account the unique needs of juvenile defendants. They go on to discuss potential problems foreseen with implementation of the JPSRB system and to recommend possible solutions.

  2. Factors affecting attitudes toward juvenile sex offenders.

    PubMed

    Sahlstrom, Kimberly J; Jeglic, Elizabeth L

    2008-01-01

    This study investigated attitudes toward juvenile sex offenders and factors influencing those attitudes. Additionally, the influences of perpetrator characteristics such as age, gender, and ethnicity on societal attitudes towards intervention requirements were also investigated. Overall, attitudes toward juvenile sex offenders and their treatment amenability were negative. No differences in attitudes toward juvenile sex offenders were found between those who had been victims of sexual abuse and those that had not. Sex offenses committed by juvenile female sex offenders were viewed to be more serious and require more intervention than those committed by juvenile male sex offenders. PMID:19042245

  3. Juvenile Diabetes and Rehabilitation Counseling.

    ERIC Educational Resources Information Center

    Stone, J. Blair; Gregg, Charles H.

    1981-01-01

    Severe complications of diabetes are more likely to occur with the juvenile diabetic and problems of psychosocial adjustment are recurring and difficult. Implications for the rehabilitation counselor are discussed in terms of employment considerations, the effects of complications, genetic counseling, and cooperation with other professionals.…

  4. Juvenile Justice and Substance Use

    ERIC Educational Resources Information Center

    Chassin, Laurie

    2008-01-01

    Laurie Chassin focuses on the elevated prevalence of substance use disorders among young offenders in the juvenile justice system and on efforts by the justice system to provide treatment for these disorders. She emphasizes the importance of diagnosing and treating these disorders, which are linked both with continued offending and with a broad…

  5. [Juvenile angiofibroma. Results of radiotherapy].

    PubMed

    Rosset, A; Korzeniowski, S

    1990-01-01

    8 patients with the nasofibromata were treated by radiotherapy in Oncologic Center in Kraków. In most part of these patients tumors exceeded the nasopharynx or gave the massive postoperational recurrencies. Complete regression was obtained in 6 out of 8 cases. The radiation changes are described. The radiotherapy is effective in more advanced and recurrent stages of the juvenile nasofibroma.

  6. Crayfish fossil burrows, a key tool for identification of terrestrial environments in tide-dominated sequence, Upper Eocene, Sirt Basin, Libya

    NASA Astrophysics Data System (ADS)

    Abouessa, Ashour; Duringer, Philippe; Schuster, Mathieu; Pelletier, Jonathan

    2015-11-01

    The majority of decapod crustaceans are defined as marine organisms. Crayfish are one of the relatively few known exceptions. They are freshwater-environment adapted decapods that build characteristically large, simple and branched cylindrical morphotype traces in fluvial plains. Their burrows bear lots of special features that make them different from other burrows. Consequently, the identification of true crayfish burrows in the sedimentary record is crucial for the interpretation of depositional environment. The studied interval (45 m thick, exposed in the Dur At Talah escarpment southern Sirt Basin; Fig. 1) represents a case-study which is previously believed to be purely tidal. In this interval, the identification of the crayfish burrows provides a reliable tool for distinguishing terrestrial environments. The crayfish burrows of Dur At Talah are characterized by dimensional, morphological, and especially behavioral aspects that combined, cannot be ascribed to another burrow makers. Essential criteria used to attribute these burrows to the crayfish include: Their length (the depth of penetration into the sediments), their regularly circular cross-sectional area, the presence of mid-way enlargement chamber along the burrow vertical axis, as well as the subtle preservation of the burrow chimney. More importantly, these morphological features allow the recognition of some of the crayfish diagnostic behavioral habits. Most significant of these is the one deduced from the interaction of the burrow with the seasonal fluctuation of the paleo groundwater level. Supplementary indications that restrict the studied burrows to terrestrial organism include their occurrences within pedogenically altered strata that bear evident features of prolonged emersion. Of these features, mud cracks and burrows that are filled with continental fossil are the clearest. Few horizons with termite fungus comb are also distinguishable. Although other burrows of the classically known

  7. Comparison of metal concentrations in the fore and hindguts of the crayfish Cambarus bartoni and Orconectes virilis and implications regarding metal absorption efficiencies

    SciTech Connect

    Bendell-Young, L.I. )

    1994-12-01

    The anthropogenic perturbation of trace metal cycle has resulted in increased emission of trace metals into the atmosphere. This has resulted in the elevation of trace metals in recently deposited sediments of lakes far removed from the original source. Benthic invertebrates, such as crayfish, live and feed directly on recently deposited sediments and are in direct contact with metals both of natural and anthropogenic origin. Crayfish may be good indicators of sediment-metal levels as they appear to retain tissue-metal concentrations that are correlated to environmental levels (e.g., for Cu, Zn and Fe). However, it is suggested that as crayfish homeostatically control tissue elemental concentrations they, in fact, cannot be used as indicators of environmental metal level. One aspect often missing is a comparison of how efficiently crayfish can absorb the element from its food under different environmental conditions. Differences in the ability of the crayfish to absorb elements from food will in turn influence ultimate tissue concentrations. One possible way to assess the importance of food as a source of elemental contamination is through gut content analysis. For essential elements not in excess (i.e., uncontaminated sites), foregut concentrations should either be equal to or greater than hindgut concentrations. Alternatively, essential elements in excess (i.e., from contaminated sites) or non-essential elements such as Cd, foregut elemental concentrations should be less than hindgut. This study aims at determining the importance of food as a source of essential (Zn, Cu, Mn, Fe, Mg and Ca) and non-essential elements (Al, Cd) in crayfish sampled from two metal and acid stressed-sites versus two non-contaminated reference sites. 22 refs., 1 fig., 2 tabs.

  8. Characterization and function of a cathepsin B in red crayfish (Procambarus clarkii) following lipopolysaccharide challenge.

    PubMed

    Dai, Li-Shang; Sun, Yu; Sun, Yu-Xuan; Zhu, Bao-Jian; Liu, Chao-Liang

    2016-09-01

    Cathepsin B is a lysosomal cysteine protease of the papain-like enzyme family with multiple biological functions. In the present study, a cathepsin B gene (named PcCTSB) was cloned and characterized from the red crayfish, Procambarus clarkii. The cDNA fragments of PcCTSB was 990 bp in length. It encoded a putative protein of 329 amino acid residues with predicted molecular weight of 36.4 kDa and isoelectric point of 7.020. Sequence alignment revealed that PcCTSB protein is 53.6%-80.4% identical with those from other 10 species. The predicted tertiary structure of PcCTSB protein was highly similar to that of animals. The results of the phylogenetic analysis indicated that the PcCTSB protein could be clustered with the Eriocheir sinensis cathepsin B protein. The recombinant protein of PcCTSB was expressed successfully in Escherichia coli cells. The mRNA expressions of PcCTSB were detected in all tested tissues, particularly high in the hepatopancreas. After lipopolysaccharide (LPS) challenge, the expression levels of PcCTSB were up-regulated significantly at different time points compared with control. Our results suggested that the PcCTSB might play an important role in defending against the pathogenes infection. PMID:27417230

  9. A Novel Chitin Binding Crayfish Molar Tooth Protein with Elasticity Properties

    PubMed Central

    Tynyakov, Jenny; Bentov, Shmuel; Abehsera, Shai; Khalaila, Isam; Manor, Rivka; Katzir Abilevich, Lihie; Weil, Simy; Aflalo, Eliahu D.; Sagi, Amir

    2015-01-01

    The molar tooth of the crayfish Cherax quadricarinatus is part of the mandible, and is covered by a layer of apatite (calcium phosphate). This tooth sheds and is regenerated during each molting cycle together with the rest of the exoskeleton. We discovered that molar calcification occurs at the pre-molt stage, unlike calcification of the rest of the new exoskeleton. We further identified a novel molar protein from C. quadricarinatus and cloned its transcript from the molar-forming epithelium. We termed this protein Cq-M13. The temporal level of transcription of Cq-M13 in an NGS library of molar-forming epithelium at different molt stages coincides with the assembly and mineralization pattern of the molar tooth. The predicted protein was found to be related to the pro-resilin family of cuticular proteins. Functionally, in vivo silencing of the transcript caused molt cycle delay and a recombinant version of the protein was found to bind chitin and exhibited elastic properties. PMID:26010981

  10. Glial fibrillary acidic protein (GFAP) shows circadian oscillations in crayfish Procambarus clarkii putative pacemakers.

    PubMed

    Rodríguez-Muñoz, María de la Paz; Escamilla-Chimal, Elsa G

    2015-01-01

    Although several studies of glia have examined glial fibrillary acid protein (GFAP) and its relationship to the circadian rhythms of different organisms, they have not explored the daily GFAP oscillations in the putative pacemakers of the crayfish Procambarus clarkii or in other crustaceans. In this study we investigated the daily variations in GFAP concentrations in the eyestalk and brain, which are considered to be putative pacemakers in adult P. clarkii. In both structures, the glial GFAP was quantified using the indirect enzyme-linked immunosorbent assay (ELISA), and double labeling immunofluorescence was used to detect it and its co-localization with protein Period (PER), an important component of the circadian clock, in various regions of both structures. The ELISA results were analyzed using Cosinor and one-way ANOVA with Bonferroni and Scheffé's post hoc tests. The results of this analysis showed that the GFAP levels present circadian oscillations in both structures. Moreover, GFAP was localized in different structures of the eyestalk and brain; however, co-localization with PER occurred only in the lamina ganglionaris, specifically in the cartridges of the eyestalk and in some of the cluster 9 brain cells. These results suggest that as in other invertebrates and vertebrates, glial cells could be involved in the circadian system of P. clarkii; however, thus far we cannot know whether the glial cells are only effectors, participate in afferent pathways, or are part of the circadian clock.

  11. Photodynamic injury of isolated crayfish neuron and surrounding glial cells: the role of p53

    NASA Astrophysics Data System (ADS)

    Sharifulina, S. A.; Uzdensky, A. B.

    2015-03-01

    The pro-apoptotic transcription factor p53 is involved in cell responses to injurious impacts. Using its inhibitor pifithrin- α and activators tenovin-1, RITA and WR-1065, we studied its potential participation in inactivation and death of isolated crayfish mechanoreceptor neuron and satellite glial cells induced by photodynamic treatment, a strong inducer of oxidative stress. In dark, p53 activation by tenovin-1 or WR-1065 shortened activity of isolated neurons. Tenovin-1 and WR-1065 induced apoptosis of glial cells, whereas pifithrin-α was anti-apoptotic. Therefore, p53 mediated glial apoptosis and suppression of neuronal activity after axotomy. Tenovin-1 but not other p53 modulators induced necrosis of axotomized neurons and surrounding glia, possibly, through p53-independent pathway. Under photodynamic treatment, p53 activators tenovin-1 and RITA enhanced glial apoptosis indicating the pro-apoptotic activity of p53. Photoinduced necrosis of neurons and glia was suppressed by tenovin-1 and, paradoxically, by pifithrin-α. Modulation of photoinduced changes in the neuronal activity and necrosis of neurons and glia was possibly p53-independent. The different effects of p53 modulators on neuronal and glial responses to axotomy and photodynamic impact were apparently associated with different signaling pathways in neurons and glial cells.

  12. Sodium channel inactivation in the crayfish giant axon. Must channels open before inactivating

    SciTech Connect

    Bean, B.P.

    1981-09-01

    Experiments on sodium channel inactivation kinetics were performed on voltage-clamped crayfish giant axons. The primary goals was to investigate whether channels must open before activating. Voltage-clamp artifacts were minimized by the use of low-sodium solutions and full series resistance compensation, and the spatial uniformity of the currents was checked with a closely spaced pair of electrodes used to measure local current densities. For membrane potentials between -40 and +40 mV, sodium currents decay to zero with a single exponential time-course. The time constant for decay is a steep function of membrane potential. The time-course of inactivation measured with the double-pulse method is very similar to the decay of current at the same potential. Steady-state inactivation curves measured with different test pulses are identical. The time-course of doubling pulse inactivation shows a lag that roughly correlates with the opening of sodium channels, but it is not strictly necessary for channels to open before inactivating. Measurements of the potential dependence of the integral of sodium conductance are also inconsistent with the simplest cases of models in which channels must open before activating.

  13. A Habitat Suitability Model for Selected Crayfish Species in Lancaster County,Pennsylvania, Streams

    NASA Astrophysics Data System (ADS)

    Laverty, S.; Buchanan, R.; Wagner, J.; Wallace, J.; Perry, B.

    2005-05-01

    The introduction of invasive exotic species to previously inaccessible areas provides the opportunity to study the impacts of invasive species on closely related native species. Habitat suitability index [HSI] models offer a coarse estimate of the habitat quality relative to hypothesized physiological tolerances of a species. The distribution and abundance of two native [Orconectes obscurus and Cambarus bartonii] and one invasive [Orconectes rusticus] crayfish along a twenty-three mile length of a Lancaster County, PA, stream and various physical factors at the sample sites were provided by a recent survey (Wagner et.al. unpublished). Of the factors provided, stream width, velocity, pH, and temperature were considered as the factors defining the geographic range of each species. An HSI model was constructed based on these factors to identify regions offering suitable habitat for a species and areas of a stream which are at risk for invasion of O. rusticus. Current work involves the development of subindices describing the availability of food and shelter within the stream, using stream order, link magnitude, and substrate measurements. The HSI model will be coupled to a model describing the interactions between size-structured populations of native and invasive species under the influence of a predator.

  14. Field and laboratory tests on acute toxicity of cadmium to freshwater crayfish

    SciTech Connect

    Not Available

    1986-09-01

    Environmental regulatory standards for cadmium (EPA 1980), like those for most pollutants, are based on acute, laboratory toxicity tests of single species. Such tests can be conducted rapidly and inexpensively in comparison to acute or chronic field studies, but their validity has often been questioned. Laboratory-based criteria are subject to two criticisms: (1) chemical and physical conditions differ greatly in degree and variability from laboratory to field, and (2) species are not isolated, but live in an ecosystem of interacting taxa and biofeedback. To investigate the validity of basing field toxicity standards on laboratory data, the authors subjected the freshwater crayfish Orconectes immunis for 96 h to various levels of cadmium in laboratory aquaria and experimental ponds. The study was designed to evaluate in part the first criticism of lab-based criteria. The studies were conducted concurrently with similar short-term experiments on the fathead minnow, Pimephales promelas, and coincided with studies of chronic cadmium stress on fathead minnows in experimental ponds.

  15. Membrane Potentials, Synaptic Responses, Neuronal Circuitry, Neuromodulation and Muscle Histology Using the Crayfish: Student Laboratory Exercises

    PubMed Central

    2011-01-01

    The purpose of this report is to help develop an understanding of the effects caused by ion gradients across a biological membrane. Two aspects that influence a cell's membrane potential and which we address in these experiments are: (1) Ion concentration of K+ on the outside of the membrane, and (2) the permeability of the membrane to specific ions. The crayfish abdominal extensor muscles are in groupings with some being tonic (slow) and others phasic (fast) in their biochemical and physiological phenotypes, as well as in their structure; the motor neurons that innervate these muscles are correspondingly different in functional characteristics. We use these muscles as well as the superficial, tonic abdominal flexor muscle to demonstrate properties in synaptic transmission. In addition, we introduce a sensory-CNS-motor neuron-muscle circuit to demonstrate the effect of cuticular sensory stimulation as well as the influence of neuromodulators on certain aspects of the circuit. With the techniques obtained in this exercise, one can begin to answer many questions remaining in other experimental preparations as well as in physiological applications related to medicine and health. We have demonstrated the usefulness of model invertebrate preparations to address fundamental questions pertinent to all animals. PMID:21304459

  16. Membrane potentials, synaptic responses, neuronal circuitry, neuromodulation and muscle histology using the crayfish: student laboratory exercises.

    PubMed

    Baierlein, Brittany; Thurow, Alison L; Atwood, Harold L; Cooper, Robin L

    2011-01-18

    The purpose of this report is to help develop an understanding of the effects caused by ion gradients across a biological membrane. Two aspects that influence a cell's membrane potential and which we address in these experiments are: (1) Ion concentration of K+ on the outside of the membrane, and (2) the permeability of the membrane to specific ions. The crayfish abdominal extensor muscles are in groupings with some being tonic (slow) and others phasic (fast) in their biochemical and physiological phenotypes, as well as in their structure; the motor neurons that innervate these muscles are correspondingly different in functional characteristics. We use these muscles as well as the superficial, tonic abdominal flexor muscle to demonstrate properties in synaptic transmission. In addition, we introduce a sensory-CNS-motor neuron-muscle circuit to demonstrate the effect of cuticular sensory stimulation as well as the influence of neuromodulators on certain aspects of the circuit. With the techniques obtained in this exercise, one can begin to answer many questions remaining in other experimental preparations as well as in physiological applications related to medicine and health. We have demonstrated the usefulness of model invertebrate preparations to address fundamental questions pertinent to all animals.

  17. Direct Age Determination of a Subtropical Freshwater Crayfish (Redclaw, Cherax quadricarinatus) Using Ossicular Growth Marks

    PubMed Central

    Leland, Jesse C.; Bucher, Daniel J.; Coughran, Jason

    2015-01-01

    Recent studies have reported that crustacean age determination is possible. We applied a direct ageing method (i.e. transverse cross sectioning of gastric ossicles) to a subtropical freshwater crayfish (Cherax quadricarinatus) sourced from an aquaculture population. Growth mark periodicity and the potential for chronological depositions were investigated by staining C. quadricarinatus with calcein and examining their ossicles a year later. Pterocardiac ossicles were superior to other ageing structures (i.e. other ossicles and eyestalks) and produced repeatable between-reader counts (87% were corroborated and 13% varied by ±1). C. quadricarinatus size-at-age data (for an aquaculture population) was described by a von Bertalanffy growth equation (L∞ = 32 mm occipital carapace length; K = 0.64; t0 = –0.18; R2 = 0.81). Ossicular growth marks did not correspond to moult history. The calcein stain was retained over an annual cycle comprising multiple moults, demonstrating that pterocardiac ossicles retain chronological information. The maximum age (3+) corroborated other indirectly-obtained longevity estimates for C. quadricarinatus. Multiple lines of evidence indicate that the growth marks in C. quadricarinatus ossicles are probably deposited annually during winter. The ability to extract age information from subtropical decapods provides substantial opportunities for advancing fisheries and conservation research globally, but further research is needed to provide a definitive validation and elucidate the mechanism governing the accrual of ossicular growth marks. PMID:26309228

  18. Voltage-dependent dye coupling at a rectifying electrotonic synapse of the crayfish.

    PubMed Central

    Giaume, C; Korn, H

    1984-01-01

    At the crayfish giant motor synapse, the lateral giant axon (l.g.a.) and the giant motor fibre (g.m.f.) form an electrotonic junction which exhibits two states of ionic coupling (Furshpan & Potter, 1959a; Giaume & Korn, 1983). Junctional conductance is low at resting membrane potentials (i.e. with lateral axon more negative than the motor fibre) and high when the polarity of the voltage difference (delta V) across the synapse is reversed. For these two states of conductance, junctional permeability was investigated using the intercellular tracer Lucifer Yellow. The dye was ionophoretically injected into either the presynaptic (l.g.a.) or the post-synaptic (g.m.f.) cell. In the high conductance state (delta V greater than 0), fluorescence was detected in both neurones whether Lucifer Yellow had been injected pre- or post-synaptically. By contrast, at the resting junctional polarization (delta V less than 0) Lucifer Yellow spread from the giant axon to the g.m.f., but not from the g.m.f. to the giant axons. These data demonstrate that dye transfer at the giant motor synapse, like ionic coupling, is sensitive to junctional polarization and is more marked in the high conductance state. Possible explanations for the asymmetry observed in the low conductance state are discussed. Images PLATE 1 PLATE 2 PLATE 3 PMID:6097668

  19. Extracellular Recording of Light Responses from Optic Nerve Fibers and the Caudal Photoreceptor in the Crayfish

    PubMed Central

    Nesbit, Steven C.; Van Hoof, Alexander G.; Le, Chi C.; Dearworth, James R.

    2015-01-01

    Few laboratory exercises have been developed using the crayfish as a model for teaching how neural processing is done by sensory organs that detect light stimuli. This article describes the dissection procedures and methods for conducting extracellular recording from light responses of both the optic nerve fibers found in the animal’s eyestalk and from the caudal photoreceptor located in the ventral nerve cord. Instruction for ADInstruments’ data acquisition system is also featured for the data collection and analysis of responses. The comparison provides students a unique view on how spike activities measured from neurons code image-forming and non-image-forming processes. Results from the exercise show longer latency and lower frequency of firing by the caudal photoreceptor compared to optic nerve fibers to demonstrate evidence of different functions. After students learn the dissection, recording procedure, and the functional anatomy, they can develop their own experiments to learn more about the photoreceptive mechanisms and the sensory integration of modalities by these light-responsive interneurons. PMID:26557793

  20. Calcium Deposits in the Crayfish, Cherax quadricarinatus: Microstructure Versus Elemental Distribution.

    PubMed

    Luquet, Gilles; Dauphin, Yannicke; Percot, Aline; Salomé, Murielle; Ziegler, Andreas; Fernández, Maria S; Arias, José L

    2016-02-01

    The crayfish Cherax quadricarinatus stores calcium ions, easily mobilizable after molting, for calcifying parts of the new exoskeleton. They are chiefly stored as amorphous calcium carbonate (ACC) during each premolt in a pair of gastroliths synthesized in the stomach wall. How calcium carbonate is stabilized in the amorphous state in such a biocomposite remains speculative. The knowledge of the microstructure at the nanometer level obtained by field emission scanning electron microscopy and atomic force microscopy combined with scanning electron microscopy energy-dispersive X-ray spectroscopy, micro-Raman and X-ray absorption near edge structure spectroscopy gave relevant information on the elaboration of such an ACC-stabilized biomineral. We observed nanogranules distributed along chitin-protein fibers and the aggregation of granules in thin layers. AFM confirmed the nanolevel structure, showing granules probably surrounded by an organic layer and also revealing a second level of aggregation as described for other crystalline biominerals. Raman analyses showed the presence of ACC, amorphous calcium phosphate, and calcite. Elemental analyses confirmed the presence of elements like Fe, Na, Mg, P, and S. P and S are heterogeneously distributed. P is present in both the mineral and organic phases of gastroliths. S seems present as sulfate (probably as sulfated sugars), sulfonate, sulfite, and sulfoxide groups and, in a lesser extent, as sulfur-containing amino acids.

  1. Isolation and preliminary characterization of a new pathogenic iridovirus from redclaw crayfish Cherax quadricarinatus.

    PubMed

    Xu, Limei; Wang, Tiantian; Li, Fang; Yang, Feng

    2016-06-15

    We report the preliminary characterization of a new iridovirus detected in diseased Cherax quadricarinatus collected from a farm in Fujian, China. Transmission electron microscopy identified numerous icosahedral particles (~150 nm in diameter) in the cytoplasm and budding from the plasma membrane of hematopoietic tissue cells. SDS-PAGE of virions semi-purified from the hemolymph of moribund C. quadricarinatus identified 24 proteins including a 50 kDa major capsid protein (MCP). By summing the sizes of DNA restriction endonuclease fragments, the viral genome was estimated to be ~150 kb in length. A 34 amino acid sequence deduced from a 103 bp MCP gene region amplified by PCR using degenerate primers targeted to MCP gene regions conserved among iridoviruses and chloriridoviruses was most similar (55% identity) to Sergestid iridovirus. Based on virion morphology, protein composition, DNA genome length, and MCP sequence relatedness, the virus identified has tentatively been named Cherax quadricarinatus iridovirus (CQIV). In addition, experimental infection of healthy C. quadricarinatus, Procambarus clarkii, and Litopenaeus vannamei with CQIV caused the same disease and high mortality, suggesting that CQIV poses a potential threat to cultured and wild crayfish and shrimp. PMID:27304867

  2. Differential effects of diltiazem on glutamate potentials and excitatory junctional potentials at the crayfish neuromuscular junction.

    PubMed Central

    Ishida, M; Shinozaki, H

    1980-01-01

    1. The effects of diltiazem on glutamate potentials and excitatory junctional potentials (e.j.p.s) were investigated in the crayfish neuromuscular junction. 2. When diltiazem (0.3 mM) was added to the perfusion fluid, the ionophoretic glutamate potential was reduced to about half, whereas the peak amplitude of successive e.j.p.s elicited by a train of pulses of 100/sec increased by about 2 times. 3. It was suggested that diltiazem was a non-competitive inhibitor of L-glutamate. The reduction of the response to applied glutamate was not due to the acceleration of desensitization of the glutamate receptor. The rate of recovery from desensitization was delayzed by diltiazem. 4. The increase in amplitude of e.j.p.s caused by diltiazem was due to the increase in membrane resistance. The quantum content and size of extracellular e.j.p.s were not affected by diltiazem. 5. It was substantiated using the micro-electrode technique that the glutamate sensitive area coincided with the neuromuscular junctional area. 6. The pharmacological difference between glutamate potentials and e.j.p.s revealed in the present study is difficult to explain on the glutamate transmitter hypothesis. One explanation worthy to be considered is that there are two pharmacologically different kinds of receptors sensitive to L-glutamate. PMID:7359406

  3. Phylogeography of Cambarus tenebrosus: a Facultative Cave-Dwelling Freshwater Crayfish Species.

    NASA Astrophysics Data System (ADS)

    Finlay, J.; Buhay, J. E.; Crandall, K. A.

    2005-05-01

    Cambarus tenebrosus is a unique freshwater crayfish species, inhabiting both subterranean and surface habitats in southeastern United States. This facultative cave-dweller is found in all aquatic karst areas within its range, including deep pits, massive underground rivers, springs, and surface streams, which makes this species ideal for a phylogeographic study. The objectives of our research are to: 1.) determine if C. tenebrosus is a single lineage or represents multiple cryptic species using phylogenetic methods, 2.) evaluate the evolutionary history and current gene flow patterns of C. tenebrosus using Nested Clade Analysis, and 3.) assess genetic diversity and conservation status of the species. We have gathered molecular genetic data from over 300 individuals from cave and surface environments across the entire range, with focus on the Cumberland Plateau from Kentucky to Alabama. Preliminary findings suggest that there are several clades of C. tenebrosus, but these clades geographically overlap in many areas. There is also no association between genetics and habitat (surface vs. subsurface), suggesting that there is gene flow between the two environment types. The origin of the species appears to be around Western Kentucky and Indiana, which then expanded southward down the Cumberland Plateau.

  4. Motion detection and adaptation in crayfish photoreceptors. A spatiotemporal analysis of linear movement sensitivity

    PubMed Central

    1991-01-01

    Impulse and sine wave responses of crayfish photoreceptors were examined to establish the limits and the parameters of linear behavior. These receptors exhibit simple low pass behavior which is well described by the transfer function of a linear resistor-capacitor cascade of three to five stages, each with the same time constant (tau). Additionally, variations in mean light intensity modify tau twofold and the contrast sensitivity by fourfold. The angular sensitivity profile is Gaussian and the acceptance angle (phi) increases 3.2-fold with dark adaptation. The responses to moving stripes of positive and negative contrast were measured over a 100-fold velocity range. The amplitude, phase, and waveform of these responses were predicted from the convolution of the receptor's impulse response and angular sensitivity profile. A theoretical calculation based on the convolution of a linear impulse response and a Gaussian sensitivity profile indicates that the sensitivity to variations in stimulus velocity is determined by the ratio phi/tau. These two parameters are sufficient to predict the velocity of the half-maximal response over a wide range of ambient illumination levels. Because phi and tau vary in parallel during light adaptation, it is inferred that many arthropods can maintain approximately constant velocity sensitivity during large shifts in mean illumination and receptor time constant. The results are discussed relative to other arthropod and vertebrate receptors and the strategies that have evolved for movement detection in varying ambient illumination. PMID:2056307

  5. Decrease in excitability of LG following habituation of the crayfish escape reaction.

    PubMed

    Araki, Makoto; Nagayama, Toshiki

    2005-05-01

    Crayfish escapes from threatening stimuli to the abdomen by tailflipping upwards and forwards. This lateral giant (LG)-mediated escape reaction habituates readily upon repetitive sensory stimulation. Using an isolated abdominal nerve cord preparation, we have analyzed the change in LG activity by applying additional sensory stimulation after different periods following habituation to characterize the retention of LG habituation. Results show that the LG mediated response habituates more quickly, but the retention time is shorter, as repetitive sensory stimulation is applied at progressively shorter inter-stimulus time intervals. The spike response of LG recovers quickly, within several minutes after habituation, but they fail to spike when an additional stimulus is applied after specific long periods following habituation. The critical period of the delay for this decrease in excitability of LG is dependent on the inter-stimulus time interval of the initial repetitive stimulus. As the inter-stimulus interval became longer, the delay needed for decrease in excitability became shorter. Furthermore, the local injection of 10(-6) mol l-1 octopamine into the neuropil just following habituation promotes the achievement of decrease in excitability. No effects were observed when 10(-6) mol l-1 serotonin and tyramine were injected. These results suggested octopamine promotes decrease in excitability of LG following habituation.

  6. IP3-mediated octopamine-induced synaptic enhancement of crayfish LG neurons.

    PubMed

    Araki, Makoto; Nagayama, Toshiki

    2012-08-01

    The biogenic amines, octopamine and serotonin, modulate the synaptic activity of the lateral giant interneuron (LG) circuitry of the crayfish escape behavior. Bath application of both octopamine and serotonin enhances the synaptic responses of LG to sensory stimulation. We have shown previously (Araki et al. J Neurophysiol 94:2644-2652, 2005) that a serotonin-induced enhancement of the LG response was mediated by an increase in cAMP levels following activation of adenylate cyclase; however, octopamine acts independently. Here, we clarify how octopamine enhances the LG response during sensory stimulation using physiological and pharmacological analyses. When phospholipase C inhibitor U-73122 was directly injected into the LG before biogenic amine application, it abolished the enhancing effect of octopamine on direct sensory input to the LG, but did not block indirect input via sensory interneurons or the effect of serotonin. Direct injection of IP(3), and its analogue adenophostin A, into the LG increased the synaptic response of the LG to sensory stimulation. Thus, IP(3) mediates octopamine-induced synaptic enhancement of the LG, but serotonin acts independently. These results indicate that both octopamine and serotonin enhance the synaptic responses of the LG to sensory stimulation, but that they activate two different signaling cascades in the LG.

  7. Calcium Deposits in the Crayfish, Cherax quadricarinatus: Microstructure Versus Elemental Distribution.

    PubMed

    Luquet, Gilles; Dauphin, Yannicke; Percot, Aline; Salomé, Murielle; Ziegler, Andreas; Fernández, Maria S; Arias, José L

    2016-02-01

    The crayfish Cherax quadricarinatus stores calcium ions, easily mobilizable after molting, for calcifying parts of the new exoskeleton. They are chiefly stored as amorphous calcium carbonate (ACC) during each premolt in a pair of gastroliths synthesized in the stomach wall. How calcium carbonate is stabilized in the amorphous state in such a biocomposite remains speculative. The knowledge of the microstructure at the nanometer level obtained by field emission scanning electron microscopy and atomic force microscopy combined with scanning electron microscopy energy-dispersive X-ray spectroscopy, micro-Raman and X-ray absorption near edge structure spectroscopy gave relevant information on the elaboration of such an ACC-stabilized biomineral. We observed nanogranules distributed along chitin-protein fibers and the aggregation of granules in thin layers. AFM confirmed the nanolevel structure, showing granules probably surrounded by an organic layer and also revealing a second level of aggregation as described for other crystalline biominerals. Raman analyses showed the presence of ACC, amorphous calcium phosphate, and calcite. Elemental analyses confirmed the presence of elements like Fe, Na, Mg, P, and S. P and S are heterogeneously distributed. P is present in both the mineral and organic phases of gastroliths. S seems present as sulfate (probably as sulfated sugars), sulfonate, sulfite, and sulfoxide groups and, in a lesser extent, as sulfur-containing amino acids. PMID:26818557

  8. Comparison of directional selectivity in identified spiking and nonspiking mechanosensory neurons in the crayfish Orconectes limosus.

    PubMed Central

    Tautz, J; Plummer, M R

    1994-01-01

    We have recorded electrical activity from two identified synaptically coupled mechanosensory interneurons in the abdominal nervous system of the crayfish Orconectes limosus and have studied their responses to constant-velocity water-jet stimuli presented from different directions. The two neurons, the ascending caudal photoreceptor (CPR) and the local directionally selective neuron, responded preferentially to stimuli delivered ipsilaterally to their dendritic input regions. Both neurons featured responses consisting of a phasic excitatory "on" response and a tonic depolarizing plateau. The different response components showed various degrees of directional selectivity: The initial "on" peak of the response was the least sensitive and the plateau was the most sensitive to stimulus direction. The CPR showed a sharp cut-off in responsiveness to contralateral stimuli, whereas the local directionally selective neuron showed a more gradual decrease in its directional responsiveness. This difference is a consequence of the feed-forward lateral inhibition that the local directionally selective neuron exerts on the CPR and of the threshold for initiation of action potentials in the CPR. A comparison of the spiking response of the CPR with its generator potential shows that the number and frequency of action potentials are a more sensitive indicator of directional preference than the generator potential response. The directional characteristic of the CPR is discussed as a filter matched to a specific spatial aspect of biologically relevant water movements. Images PMID:7517037

  9. Embryonic development of the histaminergic system in the ventral nerve cord of the Marbled Crayfish (Marmorkrebs).

    PubMed

    Rieger, V; Harzsch, S

    2008-04-01

    The embryonic development of neurotransmitter systems in crustaceans so far is poorly understood. Therefore, in the current study we monitored the ontogeny of histamine-immunoreactive neurons in the ventral nerve cord of the Marbled Crayfish, an emerging crustacean model system for developmental studies. The first histaminergic neurons arise around 60% of embryonic development, well after the primordial axonal scaffold of the ventral nerve cord has been established. This suggests that histaminergic neurons do not serve as pioneer neurons but that their axons follow well established axonal tracts. The developmental sequence of the different types of histaminergic neurons is charted in this study. The analysis of the histaminergic structures is also extended into adult specimens, showing a persistence of embryonic histaminergic neurons into adulthood. Our data are compared to the pattern of histaminergic neurons in other crustaceans and discussed with regard to our knowledge on other aspects of neurogenesis in Crustacea. Furthermore, the possible role of histaminergic neurons as characters in evolutionary considerations is evaluated.

  10. Voltage-dependent drug blockade of L-glutamate activated channels of the crayfish.

    PubMed Central

    Dekin, M S; Edwards, C

    1983-01-01

    The actions of d-tubocurarine (d-TC) and local anaesthetics on the L-glutamate activated channel at the voltage-clamped crayfish neuromuscular junction were studied. The effect of d-TC and local anaesthetics on the dose-response relationship between ionophoretically applied L-glutamate and synaptic current suggested that both acted as non-competitive inhibitors. The amount of inhibition was voltage dependent, and increased as the membrane potential was hyperpolarized. This voltage-dependent block was also manifest in a flattening of the I-V relationship between L-glutamate induced current and membrane potential in the presence of d-TC. However, the reversal potential for the L-glutamate activated channel was not affected; it was about +7 mV in both the presence and absence of d-TC. The neurally evoked excitatory post-synaptic current (e.p.s.c.) was depressed in the presence of these drugs and this effect was also voltage dependent. The time course of the e.p.s.c. was affected, but less so than expected if the L-glutamate activated channel were identical to the channel opened by acetylcholine at the vertebrate neuromuscular junction. Possible reasons for this discrepancy are discussed. PMID:6312026

  11. A Classic Improved: Minor Tweaks Yield Major Benefits in Crayfish Slow-Flexor Preparations

    PubMed Central

    Weller, Cynthia; Hochhaus, A. Maren; Wright, T. Michael; Mulloney, Brian

    2015-01-01

    Action potentials and the postsynaptic potentials they evoke fill the pages of neuroscience textbooks, but students have relatively few opportunities to record these phenomena on their own. However, the act of making such recordings can be key events in a student’s scientific education. The crayfish abdominal slow flexor muscle system is a well-established platform for recording spikes and PSPs. It enables students to see nerves and the muscles they innervate, record spontaneous spikes from several motor axons in these nerves as well as PSPs in their postsynaptic muscle fibers, and interpret these recordings quantitatively. Here we describe an improved method for preparing the slow-flexor system for recording that employs transmitted illumination through the stereo microscope’s conventional substage lighting. Oblique transmitted lighting allows students to see the nerve and muscles fibers in each segment clearly and position recording electrodes accurately under visual control. Because students can see the nerves, muscles, and recording electrodes, broken electrode tips are relatively uncommon and the first successful recordings come more quickly. Many kinds of neurons in the CNS have the same pattern of multineuronal, multiterminal innervation that occurs on these muscle fibers. To visualize these innervation patterns on these fibers, we describe an immunohistochemical protocol that labels the GABAergic inhibitory motor axon and all the synaptic vesicles in the synaptic terminals on these muscle fibers. Dual-color images reveal extensive branching of the axons and fields of presynaptic terminals, only some of which are double-labeled for GABA. PMID:25838805

  12. The pH dependency of relative ion permeabilities in the crayfish giant axon.

    PubMed

    Strickholm, A; Wallin, B G; Shrager, P

    1969-07-01

    The dependence of the membrane potential on potassium, chloride, and sodium ions, was determined at the pH's of 6.0, 7.5, and 9.0 for the resting and depolarized crayfish ventral nerve cord giant axon. In normal saline (external potassium = 5.4 mM), the dependence of the membrane potential on the external potassium ions decreased with lowered pH while that for chloride increased. In contrast, in the potassium depolarized axon (external potassium = 25 mM), the dependence of the membrane potential on external potassium was minimum around pH 7.5 and increased in either more acidic or basic pH. In addition, the dependence of the membrane potential on external chloride in the depolarized axon was maximum at pH 7.5 and decreased in either more acidic or basic pH. The sodium dependency of the membrane potential was small and relatively unaffected by pH or depolarization. The data are interpreted as indicating a reversible surface membrane protein-phospholipid conformation change which occurs in the transition from the resting to the depolarized axon. PMID:5791546

  13. Insights into the molecular phylogeny and historical biogeography of the white-clawed crayfish (Decapoda, Astacidae).

    PubMed

    Jelić, Mišel; Klobučar, Göran I V; Grandjean, Frédéric; Puillandre, Nicolas; Franjević, Damjan; Futo, Momir; Amouret, Julien; Maguire, Ivana

    2016-10-01

    In this study, the evolutionary history of the white-clawed crayfish (WCC) was evaluated using large-scale datasets comprising >1350 specimens from the entire distribution range. Using species delimitation methods on mitochondrial DNA (mtDNA) sequences, we propose four primary species hypotheses for WCC. Sequences for several nuclear regions were screened but none showed significant variation within WCC. This result favours a single secondary species hypothesis and indicates the existence of a mito-nuclear discordance in WCC. Therefore, mtDNA groups were considered only as genetic units that carry information about ancient divergences within WCC and not as taxonomic units. The reconstruction of ancestral ranges and divergence time estimates were used to link the current genetic structure with paleogeographic processes. These results showed that the emergence of mtDNA groups in WCC could be related to the Messinian Salinity Crisis, the climate cooling during the Pliocene and Pleistocene, and (paleo)shifting of the Adriatic Sea coastline in the Padanovenezian Plain. The most recent common ancestor of the mtDNA groups most likely originated from Dalmatia (eastern Adriatic coast) as indicated by the reconstruction of ancestral ranges. This ecoregion, along with the Gulf of Venice Drainages, harbours a high genetic diversity and should be emphasised as an area of the highest conservation priority. PMID:27404041

  14. Direct Age Determination of a Subtropical Freshwater Crayfish (Redclaw, Cherax quadricarinatus) Using Ossicular Growth Marks.

    PubMed

    Leland, Jesse C; Bucher, Daniel J; Coughran, Jason

    2015-01-01

    Recent studies have reported that crustacean age determination is possible. We applied a direct ageing method (i.e. transverse cross sectioning of gastric ossicles) to a subtropical freshwater crayfish (Cherax quadricarinatus) sourced from an aquaculture population. Growth mark periodicity and the potential for chronological depositions were investigated by staining C. quadricarinatus with calcein and examining their ossicles a year later. Pterocardiac ossicles were superior to other ageing structures (i.e. other ossicles and eyestalks) and produced repeatable between-reader counts (87% were corroborated and 13% varied by ±1). C. quadricarinatus size-at-age data (for an aquaculture population) was described by a von Bertalanffy growth equation (L∞ = 32 mm occipital carapace length; K = 0.64; t0 = -0.18; R2 = 0.81). Ossicular growth marks did not correspond to moult history. The calcein stain was retained over an annual cycle comprising multiple moults, demonstrating that pterocardiac ossicles retain chronological information. The maximum age (3+) corroborated other indirectly-obtained longevity estimates for C. quadricarinatus. Multiple lines of evidence indicate that the growth marks in C. quadricarinatus ossicles are probably deposited annually during winter. The ability to extract age information from subtropical decapods provides substantial opportunities for advancing fisheries and conservation research globally, but further research is needed to provide a definitive validation and elucidate the mechanism governing the accrual of ossicular growth marks. PMID:26309228

  15. Juvenile Crime, Juvenile Justice. Panel on Juvenile Crime: Prevention, Treatment, and Control.

    ERIC Educational Resources Information Center

    McCord, Joan, Ed.; Widom, Cathy Spatz, Ed.; Crowell, Nancy A., Ed.

    This book discusses patterns and trends in crimes committed by children and adolescents, analyzing youth crime as a subset of general crime and studying the impact of race and gender. It evaluates different approaches to forecasting future crime rates. Data come from a national panel that examined what is known about juvenile crime and its…

  16. The distributions of one invasive and two native crayfishes in relation to coarse-scale natural and anthropogenic factors

    USGS Publications Warehouse

    Westhoff, J.T.; Rabeni, C.F.; Sowa, S.P.

    2011-01-01

    1. Native crayfishes are often extirpated from portions of their range because of interactions with invasive species, anthropogenic alterations to environmental conditions or a combination of these factors. Our goal was to identify coarse-scale natural and anthropogenic factors related to the current distributions of the invasive crayfish, Orconectes hylas, and two endemic crayfishes, Orconectes peruncus andOrconectes quadruncus in the St. Francis River drainage, Missouri, U.S.A. and to provide wider insights into the potential role of anthropogenic factors in facilitating species displacement. 2. We used classification trees to model coarse-scale natural and anthropogenic environmental factors and their relation to the presence or absence of each species. Model results were then used to predict probability of presence for each species within each stream segment throughout the entire St. Francis River drainage. 3. Factors related to geology and soils were the best predictors of species distributions. A dichotomy of these factors explained much of the discrete distributions of the two native species. Agricultural-related factors were identified as the most influential anthropogenic activity related to species distributions. All associations between the invasive species and anthropogenic factors were negative which suggested the invader was not likely to establish in heavily impacted areas. Overall, our models had high correct classification rates, and we were able to reliably predict the presence of the invader in the invaded drainage. 4. Given the negative associations of the invader with anthropogenic alterations at a coarse spatial scale, we believe other mechanisms are likely to be responsible for the widespread displacement of the two native species. These findings can be used to assist in conservation activities such as creation of refugia for native species and may direct future research to identify the mechanism(s) of species displacement.

  17. Copper-induced oxidative damage to the prophenoloxidase-activating system in the freshwater crayfish Procambarus clarkii.

    PubMed

    Wei, Keqiang; Yang, Junxian

    2016-05-01

    Previous studies have demonstrated copper-induced proteins damage in gill and hepatopancreas of the freshwater crayfish Procambarus clarkii, but little information is available about its effects on key component of the innate defense in haemolymph. In the present study, we evaluated the relationship between oxidative carbonylation and prophenoloxidase-activating system (proPO-AS) activity, by exposing P. clarkii to sub-lethal concentrations (1/50, 1/12, 1/6 and 1/3 of the 96 h LC50) Cu(2+) up to 96 h. Six biomarkers of oxidative stress, i.e. reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), protein carbonyl (PC), malondialdehyde (MDA) and DNA-protein crosslinks (DPCs), and six indicators of immune status, i.e. total hemocyte counts (THCs), differential hemocyte counts (DHCs), hemocyanin (HC), prophenoloxidase (proPO), serine protease (SP) and phenoloxidase (PO), were determined in haemolymph. The results indicated that there was a significant increase (P < 0.05) in the levels of ROS, PC, MDA and DPCs accompanied by markedly decreased (P < 0.05) activities of proPO, SP, PO and HC in a dose and time dependent manner. The significant and positive correlations (P < 0.01) between ROS production and the formation of PC, MDA and DPCs were observed in crayfish at 96 h. There was a significant negative correlation (P < 0.01) between the levels of protein carbonyls and the activities of proPO and SP in hemocyte lysate supernatant and PO and HC in haemolymph. Carbonylated proteins may be recognized not merely as a specific signal in oxidative stress pathways but also as a "non-self" molecule in proPO-AS. In crayfish species, copper-catalyzed protein carbonylation may be one of the main mechanisms for immunity dysfunction in proPO-AS. PMID:27033468

  18. Heavy metals bioaccumulation in selected tissues of red swamp crayfish: An easy tool for monitoring environmental contamination levels.

    PubMed

    Goretti, E; Pallottini, M; Ricciarini, M I; Selvaggi, R; Cappelletti, D

    2016-07-15

    In this paper we explored the heavy metal bioaccumulation (Cd, Cu, Pb and Zn) in Procambarus clarkii, a crayfish recently suggested as a potential bioindicator for metals pollution in freshwater systems. The present study is focused on crayfishes populations caught in a heavily polluted industrial and in a reference sites (Central Italy), though the results are generalized with a thorough analysis of literature metadata. In agreement with the literature, the hepatopancreas (Hep, detoxification tissues) of the red swamp crayfish showed a higher concentration of heavy metals in comparison to the abdominal muscle (AbM, not detoxification tissues) in the sites under scrutiny. Hep/AbM concentration ratio was dependent on the specific metal investigated and on its sediment contamination level. Specifically we found that Hep/AbM ratio decreases as follows: Cd (11.7)>Cu (5.5)>Pb (3.6)>Zn (1.0) and Pb (4.34)>Cd (3.66)>Zn (1.69)>Cu (0.87) for the industrial and reference sites, respectively. The analysis of our bioaccumulation data as well as of literature metadata allowed to elaborate a specific contamination index (Toxic Contamination Index, TCI), dependent only on the bioaccumulation data of hepatopancreas and abdominal muscle. In the industrial site, TCI expressed values much higher than the unit for Cd and Cu, confirming that these metals were the main contaminants; in contrast for lower levels of heavy metals, as those observed in the reference site for Cu, Zn and Pb, the index provided values below unit. TCI is proposed as a useful and easy tool to assess the toxicity level of contaminated sites by heavy metals in the environmental management. PMID:27085675

  19. Identification of an anti-lipopolysacchride factor possessing both antiviral and antibacterial activity from the red claw crayfish Cherax quadricarinatus.

    PubMed

    Lin, Feng-Yu; Gao, Yan; Wang, Hao; Zhang, Qiu-Xia; Zeng, Chang-Lin; Liu, Hai-Peng

    2016-10-01

    It is well-known that anti-lipopolysacchride factors (ALFs) are involved in the recognition and elimination of invading pathogens. In this study, the full-length ALF cDNA sequence of the red claw crayfish Cherax quadricarinatus (termed CqALF) was cloned from a suppression subtractive hybridization library constructed using red claw crayfish hematopoietic tissue cell (Hpt cell) cultures following challenge with white spot syndrome virus (WSSV). The full-length cDNA sequence of CqALF was 863 bp, and the open reading frame encoded 123 amino acids with a signal peptide in the N-terminus and a conserved LPS-binding domain. Unlike most ALFs, which are highly expressed in haemocytes, high expression levels of CqALF were detected in epithelium, the stomach and eyestalks, while lower expression was detected in Hpt, nerves, the heart, muscle tissue, gonads, haemocytes, intestines, gills and the hepatopancreas. To further explore the biological activities of CqALF, mature recombinant CqALF protein (rCqALF) was expressed and purified using a eukaryotic expression system, and an antimicrobial activity test was carried out. rCqALF clearly exerted antiviral activity, as evidenced by the severe disruption of the envelope of intact WSSV virions following co-incubation of virions with rCqALF. Additionally, pre-incubation of WSSV with rCqALF resulted in both a significant reduction in WSSV replication in red claw crayfish Hpt cell cultures and an increased survival rate among animals. Furthermore, rCqALF was effective against both Gram-negative bacteria and Gram-positive bacteria, particularly Shigella flexneri and Staphylococcus aureus. A membrane integrity assay suggested that rCqALF was unlikely to disrupt bacterial membrane integrity compared to cecropin P1. Taken together, these data suggest that CqALF may play an important role in immune defence in the crustacean C. quadricarinatus. PMID:27544268

  20. Heavy metals bioaccumulation in selected tissues of red swamp crayfish: An easy tool for monitoring environmental contamination levels.

    PubMed

    Goretti, E; Pallottini, M; Ricciarini, M I; Selvaggi, R; Cappelletti, D

    2016-07-15

    In this paper we explored the heavy metal bioaccumulation (Cd, Cu, Pb and Zn) in Procambarus clarkii, a crayfish recently suggested as a potential bioindicator for metals pollution in freshwater systems. The present study is focused on crayfishes populations caught in a heavily polluted industrial and in a reference sites (Central Italy), though the results are generalized with a thorough analysis of literature metadata. In agreement with the literature, the hepatopancreas (Hep, detoxification tissues) of the red swamp crayfish showed a higher concentration of heavy metals in comparison to the abdominal muscle (AbM, not detoxification tissues) in the sites under scrutiny. Hep/AbM concentration ratio was dependent on the specific metal investigated and on its sediment contamination level. Specifically we found that Hep/AbM ratio decreases as follows: Cd (11.7)>Cu (5.5)>Pb (3.6)>Zn (1.0) and Pb (4.34)>Cd (3.66)>Zn (1.69)>Cu (0.87) for the industrial and reference sites, respectively. The analysis of our bioaccumulation data as well as of literature metadata allowed to elaborate a specific contamination index (Toxic Contamination Index, TCI), dependent only on the bioaccumulation data of hepatopancreas and abdominal muscle. In the industrial site, TCI expressed values much higher than the unit for Cd and Cu, confirming that these metals were the main contaminants; in contrast for lower levels of heavy metals, as those observed in the reference site for Cu, Zn and Pb, the index provided values below unit. TCI is proposed as a useful and easy tool to assess the toxicity level of contaminated sites by heavy metals in the environmental management.

  1. Determination of mercury by cold-vapor technique in several tissues of treated American red crayfish (Procambarus clarkii)

    SciTech Connect

    Del Ramo, J.; Pastor, A.; Diaz-Mayans, J.; Medina, J.; Torreblanca, A.

    1988-01-01

    Adult intermolt specimens of American red crayfish (Procambarus clarkii) collected from Lake Albufera (Valencia, Spain), were exposed to mercury during 96 h. The Hg-concentrations used were 50, 100, and 250 ..mu..g Hg/l as Cl/sub 2/Hg. The content of mercury in muscle, midgut gland, antennal glands and gills was investigated. Determinations of mercury were made by cold-vapor technique and AAS. The mercury levels in all examined tissues increased significantly with increasing Hg-concentration in the water.

  2. Recovery of Hafnia alvei from diseased brown trout, Salmo trutta L., and healthy noble crayfish, Astacus astacus (L.), in Bulgaria.

    PubMed

    Orozova, P; Sirakov, I; Chikova, V; Popova, R; Al-Harbi, A H; Crumlish, M; Austin, B

    2014-10-01

    Hafnia alvei was isolated in Bulgaria from healthy noble crayfish, Astacus astacus (L.), and then from farmed diseased brown trout, Salmo trutta L., with signs of haemorrhagic septicaemia. The isolates were identified initially with conventional phenotyping and commercial Merlin Micronaut and API 20E rapid identification systems, followed by sequencing of the 16S rRNA gene. Hafnia alvei Bt1, Bt2 and Aa4 were of low virulence to rainbow trout and brown trout, although cytotoxicity was demonstrated by Bt1 and Bt2, but not by Aa4. PMID:24422558

  3. Membrane-associated actin in the rhabdomeral microvilli of crayfish photoreceptors

    PubMed Central

    1984-01-01

    Infiltration of compound eyes of crayfish, Cherax destructor, with the thiol protease inhibitor Ep-475 or with trifluoperazine prior to fixation for electron microscopy was found to stabilize an axial filament of 6-12 nm diam within each rhabdomeral microvillus of the photoreceptors. Rhabdoms isolated from retinal homogenates by sucrose gradient centrifugation under conditions that stabilize cytoskeletal material contained large amounts of a 42-kd polypeptide that co- migrated with insect flight muscle actin in one- and two-dimensional PAGE, inhibited pancreatic DNase l, and bound to vertebrate myosin. Vertebrate skeletal muscle actin added to retinal homogenates did not co-purify with rhabdoms, implying that actin was not a contaminant from nonmembranous structures. DNase l inhibition assays of detergent-lysed rhabdoms indicated the presence of large amounts of filamentous actin provided ATP was present. Monomeric actin in such preparations was completely polymerizable only after 90 min incubation with equimolar phalloidin. More than half of the actin present could be liberated from the membrane by sonication, indicating a loose association with the membrane. However, a large proportion of the actin was tightly bound to the rhabdomeral membrane, and washing sonicated membrane fractions with solutions of a range of ionic strengths and nonionic detergents failed to remove it. Antibodies to scallop actin only bound to frozen sections of rhabdoms after gentle permeabilization and very long incubation periods, probably because of steric hindrance and the hydrophobicity of the structure. The F-actin probe nitrobenzoxadiazol phallacidin bound to rhabdoms and labeled F-actin aggregates in other retinal components, but rhabdom fluorescence was not abolished by preincubation with phalloidin. The biochemical data indicate the existence of two distinct actin-based cytoskeletal systems, one being closely membrane associated. The other may possibly constitute the axial filament

  4. Phylogeny and evolutionary patterns in the Dwarf crayfish subfamily (Decapoda: Cambarellinae).

    PubMed

    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

  5. Role of cAMP signalling in winner and loser effects in crayfish agonistic encounters.

    PubMed

    Momohara, Yuto; Minami, Hiroki; Kanai, Akihiro; Nagayama, Toshiki

    2016-07-01

    For territorial animals, establishment of status-dependent dominance order is essential to maintain social stability. In agonistic encounters of the crayfish Procambarus clarkii, a difference of body length of 3-7% is enough for larger animals to become dominant. Despite a physical disadvantage, small winners of the first pairings were more likely to win subsequent conflicts with larger inexperienced animals. In contrast, the losers of the first pairings rarely won subsequent conflicts with smaller naive animals. Such experiences of previous winning or losing affected agonistic outcomes for a long period. The winner effects lasted more than 2 weeks and the loser effect lasted about 10 days. Injection of 5HT1 receptor antagonist into the dominant animals 15-30 min after establishment of dominance order blocked the formation of the winner effects. In contrast, injection of adrenergic-like octopamine receptor antagonist into subordinate animals blocked the formation of the loser. 5HT1 receptors are negatively coupled to adenylyl cyclase and adrenergic-like octopamine receptors are positively coupled. Consistent with this, dominant animals failed to show the winner effect when injected with pCPT-cAMP, a cAMP analogue, and subordinate animals failed to show a loser effect when injected with adenylyl cyclase inhibitor SQ 22536. These results suggest that an increase and decrease of cAMP concentration is essential in mediating loser and winner effects, respectively. Furthermore, formation of the loser effect was blocked by injection of protein kinase A (PKA) inhibitor H89, suggesting long-term memory of the loser effect is dependent on the cAMP-PKA signalling pathway. PMID:27086724

  6. Resistance of a crayfish sensory interneurone to hyperinnervation by acceptable afferents.

    PubMed Central

    Krasne, F B; Lee, S H

    1982-01-01

    1. Intact normal innervation of muscle fibres and other peripheral targets usually prevents regenerating nerves from forming synapses with the targets. Whether intact innervation similarly prevents synapse formation on central target neurones has rarely been tested. This question was examined here for interneurone A of the crayfish last abdominal ganglion. 2. Interneurone A normally receives synaptic input from mechanoreceptor neurones distributed over the side of the tailfan ipsilateral to interneurone A's axon and unilateral dendrites. When the five nerve roots carrying mechanoreceptor axons of one side are cut and central and peripheral ends of one or more are sutured together, regeneration and reinnervation of interneurone A occurs over some two to six weeks. If peripheral ends of roots from the 'wrong' (contralateral) side of the body are sutured to ipsilateral central stumps, they also form connexions with interneurone A. When roots from the two sides of the body are simultaneously tied to a central stump, functional connexion formation occurs equally well for afferents from both sides. Therefore, roots of the two sides seem to be equivalent in their ability to reinnervate interneurone A. 3. If peripheral ends of roots from one side of the tailfan are tied to roots on the intact opposite side of the body, the cut axons appear to grow into the last ganglion but usually do not form functional synapses there. The intact innervation therefore seems to exclude further innervation by other acceptable afferents. 4. It is known that mechanoreceptors are added to the tailfan at moult. Exclusion of extra innervation often broke down partially in animals that moulted during the present experiments. This suggests the possibility that synapse formation or exchange may be controlled by moult-inducing hormones. PMID:7153906

  7. Changes in electrical properties and quantal current during growth of identified muscle fibres in the crayfish.

    PubMed Central

    Lnenicka, G A; Mellon, D

    1983-01-01

    The muscle fibre electrical properties, miniature excitatory junctional current (m.e.j.c.) and miniature excitatory junctional potential (m.e.j.p.) were studied during growth of an identified crayfish muscle fibre from a diameter of 20 to 400 microns. The specific membrane resistance (Rm), and the specific internal resistance (Ri), of the muscle fibre were independent of fibre diameter (d) during growth. The current-voltage relation has a similar shape in large and small fibres, indicating that voltage dependence of Rm does not change during growth. The input resistance (R0) was approximately proportional to d-1.5, as predicted theoretically. The specific membrane capacitance (Cm) and the membrane time constant (Tm) increased linearly with fibre diameter, apparently as a result of the contribution of the tubular capacitance to Cm. The decrease in R0 and the increase in Tm should have resulted in a 90-fold decrease in m.e.j.p. amplitude during growth of the fibre from a diameter of 20 to 240 microns. However, m.e.j.p. amplitude was found to decrease only 21-fold. This discrepancy was shown to result from an increase in m.e.j.c. amplitude and duration during growth. There was 2.9-fold increase in m.e.j.c. amplitude and a 2.7-fold increase in m.e.j.c. duration over the range of muscle fibre growth studied. This increase in the m.e.j.c. apparently results from an increase in the magnitude and duration of the synaptic conductance change produced by a quantum of transmitter. Throughout the range of muscle fibre diameters studied, the muscle fibre effective input impedance for the m.e.j.c. was 17-19% of R0. This is due to the relatively large Cm and the short duration of the m.e.j.c. PMID:6663501

  8. Single channel currents of different amplitude activated by glutamate in a tonic (slow) crayfish muscle.

    PubMed

    Finger, W; Pareto, A

    1987-09-11

    Single channel currents were recorded by means of the patch-clamp technique from a tonic (slow) crayfish muscle in the presence of 5 mM glutamate. The experiments were carried out with 'Gigaohm-seals' in the 'cell-attached' mode at 15-17 degrees C. Five classes of single channel currents with different mean amplitudes were resolved: i1 = -0.75 +/- 0.43 (S.D.) pA, i2 = -1.4 +/- 0.4 pA, i3 = -3.5 +/- 0.63 pA, i4 = -8.5 +/- 0.92 pA and i5 approximately equal to 2 X i4, i2, i3 and i4 were recorded at resting membrane potential, Eo approximately equal to -80 mV (pipette potential Vp = 0), while i1 and i5 were recorded at 40 mV hyperpolarized to Eo (Vp = +40 mV). The current most frequently seen was i4 which is the excitatory glutamate-activated single channel current recorded previously by Franke et al. The membrane reversal potentials and channel conductances for i2 and i4 were estimated to be +60 mV (Eo + 140 mV), 13 pS for i2 and +40 mV (Eo + 120 mV), 80 pS for i4. It was assumed that up to 40 i1 currents could superpose in a single patch to generate a DC current of up to -30 pA with current fluctuations the intensity of which increased with the DC current amplitude. Often variable combinations of i1 to i4 currents could be recorded simultaneously in a single patch. In particular, simultaneous activity of i1, i4; i2, i4 and i3, i4 currents was observed in different single patches.

  9. Juvenile morphology in baleen whale phylogeny.

    PubMed

    Tsai, Cheng-Hsiu; Fordyce, R Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  10. Juvenile morphology in baleen whale phylogeny

    NASA Astrophysics Data System (ADS)

    Tsai, Cheng-Hsiu; Fordyce, R. Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  11. Short- and long-wavelength-sensitive opsins are involved in photoreception both in the retina and throughout the central nervous system of crayfish.

    PubMed

    Kingston, Alexandra C N; Cronin, Thomas W

    2015-12-01

    Crayfish have two classes of photoreceptors in the retinas of their reflecting superposition eyes. Long-wavelength-sensitive photoreceptors, comprised of microvilli from R1-7 cells, make up the main rhabdoms. Eighth retinular cells, located distal to the main rhabdoms, house short-wavelength-sensitive photoreceptors. While the opsin involved in long-wavelength sensitivity has long been known, we present the first description of the short-wavelength-sensitive opsin in the retina of the red swamp crayfish, Procambarus clarkii. The expression patterns of these SWS and LWS opsin proteins in the retina are consistent with the previously described locations of SWS and LWS receptors. Crayfish also have a well-characterized extraocular photoreceptor, called the caudal photoreceptor, located in the sixth abdominal ganglion. To search for retinal opsins in the caudal photoreceptor (and elsewhere in the CNS), we used RT-PCR and immunohistochemical labeling. We found both SWS and LWS opsin transcripts not only in the sixth abdominal ganglion, but also in all ganglia of the nerve cord. Immunolabeling shows that both opsins are expressed in nerve fibers that extend from the brain through the entire length of the CNS. Thus, the same two photopigments are used both for vision in the retina and for extraocular functions throughout the CNS of crayfish.

  12. The acute toxicity of fenitrothion on narrow-clawed crayfish (Astacus leptodactylus Eschscholtz, 1823) in association with biomarkers of lipid peroxidation.

    PubMed

    Sarikaya, Rabia; Sepici-Dinçel, Aylin; Caǧlan Karasu Benli, A; Selvi, Mahmut; Erkoç, Figen

    2011-01-01

    The aim of this research was to evaluate the acute toxicity of fenitrothion to the crayfish (Astacus leptodactylus Eschscholtz, 1823), which is chosen as an alternative aquatic organism to fish by using the static test system and evaluate the basic lipid peroxidation parameters for the first 24 h. Crayfish of 27.3 ± 0.56 g mean weight and 10.0 ± 0.72 cm mean length were selected for the bioassay experiments. The experiments were repeated three times in 20 liters of tap water. The temperature of water was 21 ± 1°C. The data obtained were statistically evaluated by using a computer program developed by the United States Environmental Protection Agency, based on Finney's probit analysis method and the 96-h LC(50) value for crayfish was calculated to be 15.75 μg/L. The 95% lower and upper confidence limits for the LC(50) were 9.45 to 25.01 μg/L. In addition to the acute toxicity bioassay experiments, 24-h oxidative stress parameters such as malondialdehyde (MDA) levels and ferrous oxidation assay (FOX HP [hydrogen peroxide] equivalents) were also determined. Only MDA levels of hepatopancreas decreased at 5, 10, and 20 μg/L of fenitrothion doses. We can conclude that fenitrothion is highly toxic to crayfish, a nontarget organism in the ecosystem, and the lipid peroxidation indicators can be easily used for monitoring environmental effects. PMID:20957683

  13. Temporal Changes in Concentrations of Some Trace Elements in Muscle Tissue of Crayfish, Astacus leptodactylus (Eschscholtz, 1823), from Keban Dam Lake

    PubMed Central

    Aksu, Onder; Adiguzel, Ragip; Demir, Veysel; Yildirim, Numan; Danabas, Durali; Seker, Sebahat; Seyhaneyildiz Can, Safak; Ates, Mustafa

    2014-01-01

    Crayfish (Astacus leptodactylus Eschscholtz, 1823) is the native crayfish species in Turkey. It was exported regularly to Western Europe. In this study, bioaccumulation and temporal trends of some trace elements (arsenic: As, cadmium: Cd, copper: Cu, mercury: Hg, lead: Pb, and zinc: Zn) in edible abdomen muscle of crayfish from Keban Dam Lake (Elazığ, Turkey) were investigated for the 2006–2012 period. Sequence of metal concentration levels was Zn > Cu > Hg > Pb > Cd > As in muscle tissues. The highest concentration of Zn (21.69 mg kg−1) was detected in 2006, while the lowest (4.35 mg kg−1) in 2009. In general, it was found that the concentrations of trace elements investigated were lower than the maximum permissible limits of the food regulations of the Ministry of Food, Agriculture, and Livestock (MFAL), the Turkish Food Codex and Commission Regulation (EC). If the crayfish selected for the study are recognized as bioindicators of environmental pollution, then it is possible to conclude that the changes in studied trace elements concentrations in the Keban Dam Lake are being steady. PMID:24707241

  14. Sex hormones in juvenile nasopharyngeal angiofibroma tissue.

    PubMed

    Kumagami, H

    1993-01-01

    Five cases of juvenile nasopharyngeal angiofibroma were studied in terms of the presence of progesterone, estradiol, testosterone, and dihydrotestosterone in the juvenile nasopharyngeal angiofibroma tissue using the peroxidase-antiperoxidase method. Progesterone and estradiol were positive in all cases. Testosterone was positive in 2 of the 5 patients. Dihydrotestosterone was positive in 3 of the 5 patients. Hormone in the juvenile nasopharyngeal angiofibroma tissue seems to change by the activity of nasopharyngeal angiofibroma.

  15. What do metabolic rates tell us about thermal niches? Mechanisms driving crayfish distributions along an altitudinal gradient.

    PubMed

    Stoffels, Rick J; Richardson, Adam J; Vogel, Matthew T; Coates, Simon P; Müller, Warren J

    2016-01-01

    Humans are rapidly altering thermal landscapes, so a central challenge to organismal ecologists is to better understand the thermal niches of ectotherms. However, there is much disagreement over how we should go about this. Some ecologists assume that a statistical model of abundance as a function of habitat temperature provides a sufficient approximation of the thermal niche, but ecophysiologists have shown that the relationship between fitness and temperature can be complicated, and have stressed the need to elucidate the causal mechanisms underlying the response of species to thermal change. Towards this end, we studied the distribution of two crayfishes, Euastacus woiwuru and Euastacus armatus, along an altitudinal gradient, and for both species conducted experiments to determine the temperature-dependence of: (1) aerobic scope (the difference between maximum and basal metabolic rate; purported to be a proxy of the thermal niche); and (2) burst locomotor performance (primarily fuelled using anaerobic pathways). E. woiwuru occupied cooler habitats than E. armatus, but we found no difference in aerobic scope between these species. In contrast, locomotor performance curves differed significantly and strongly between species, with peak locomotor performances of E. woiwuru and E. armatus occurring at ~10 and ~18 °C, respectively. Crayfish from different thermal landscapes may have similar aerobic thermal performance curves but different anaerobic thermal performance curves. Our results support a growing body of literature implying different components of ectotherm fitness have different thermal performance curves, and further challenge our understanding of the ecology and evolution of thermal niches. PMID:26440800

  16. What do metabolic rates tell us about thermal niches? Mechanisms driving crayfish distributions along an altitudinal gradient.

    PubMed

    Stoffels, Rick J; Richardson, Adam J; Vogel, Matthew T; Coates, Simon P; Müller, Warren J

    2016-01-01

    Humans are rapidly altering thermal landscapes, so a central challenge to organismal ecologists is to better understand the thermal niches of ectotherms. However, there is much disagreement over how we should go about this. Some ecologists assume that a statistical model of abundance as a function of habitat temperature provides a sufficient approximation of the thermal niche, but ecophysiologists have shown that the relationship between fitness and temperature can be complicated, and have stressed the need to elucidate the causal mechanisms underlying the response of species to thermal change. Towards this end, we studied the distribution of two crayfishes, Euastacus woiwuru and Euastacus armatus, along an altitudinal gradient, and for both species conducted experiments to determine the temperature-dependence of: (1) aerobic scope (the difference between maximum and basal metabolic rate; purported to be a proxy of the thermal niche); and (2) burst locomotor performance (primarily fuelled using anaerobic pathways). E. woiwuru occupied cooler habitats than E. armatus, but we found no difference in aerobic scope between these species. In contrast, locomotor performance curves differed significantly and strongly between species, with peak locomotor performances of E. woiwuru and E. armatus occurring at ~10 and ~18 °C, respectively. Crayfish from different thermal landscapes may have similar aerobic thermal performance curves but different anaerobic thermal performance curves. Our results support a growing body of literature implying different components of ectotherm fitness have different thermal performance curves, and further challenge our understanding of the ecology and evolution of thermal niches.

  17. Accumulation of 14C-naphthalene in the tissues of redhead ducks fed oil-contaminated crayfish

    USGS Publications Warehouse

    Tarshis, I.B.; Rattner, B.A.

    1982-01-01

    Crayfish, artificially contaminated with14C-naphthalene-5% water-soluble fraction of No. 2 fuel oil, were force-fed to one-year-old redhead ducks to determine the accumulation of petroleum hydrocarbons. The relative distribution of carbon-14 activity in the gall bladder containing bile, and fat were similar, and significantly greater (P < 0.05) than the activity in the blood, brain, liver, and kidney. There was a significant increase (P < 0.05) in the disintegrations per minute per gram (dpm/g) in the blood, brain, kidney, and liver between days 1 and 3 of feeding, indicating a progressive accumulation of carbon-14 activity (naphthalene and presumably its metabolites). There was no significant effect of sex or the interaction of the duration of feeding and sex on carbon-14 activity in any of the tissues. The low daily dose of petroleum hydrocarbons (a total of approximately 1.25 mg/day) received by the ducks from the crayfish and the relatively short feeding regimen did not cause any overt signs of toxicity in the ducks.

  18. Operant avoidance learning in crayfish, Orconectes rusticus: Computational ethology and the development of an automated learning paradigm.

    PubMed

    Bhimani, Rohan; Huber, Robert

    2016-09-01

    Research in crustaceans offers a valuable perspective for studying the neural implementation of conserved behavioral phenomena, including motivation, escape, aggression, and drug-sensitive reward. The present work adds to this literature by demonstrating that crayfish successfully learn to respond to spatially contingent cues. An integrated video-tracking system automatically delivered a mild electric shock when a test animal entered or remained on a substrate paired with punishment. Following a few instances of shock delivery, crayfish quickly learned to avoid these areas. Comparable changes in substrate preference were not exhibited by yoked controls, but locomotion differed significantly from both pre-conditioning levels and from those of their masters receiving shock in a contingent fashion. The results of this work provide valuable insights into the principles governing avoidance learning in an invertebrate system and provide a behavioral template for exploring the neural changes during associative learning. Serving as a case study, this project introduces a new computer framework for the automated control of learning paradigms. Based on routines contained within the JavaGrinders library (free download at iEthology.com), it integrates real-time video tracking with robotic interfaces, and provides a suitable framework for implementing automated learning paradigms.

  19. Assessment of neuroglial relationships under photodynamic treatment using fluorescent visualization of giant axons in crayfish ventral nerve cord

    NASA Astrophysics Data System (ADS)

    Duz, Eugeny; Kolosov, Mikhail S.

    2014-01-01

    There are lots of publications last time about important role of neuroglial interactions in normal physiology of nervous system. Some of them infer that neuroglial interactions may support survival of neuronal and glial cells. Study the mechanisms of neuroglial interactions needs convenient models which are simple nervous system. They could be easily isolated and studied while retain natural neuroglial relations. The purpose of present work was to estimate glia protective properties of giant axons in simple model - crayfish ventral nerve cord, upon photooxidative stress. To better visualize the axons shape and reveal the periaxonal glial cells, we were filling of the axons with fluorescent label by means of specially devised microinjector. It enabled us to reveal the glial cells which are in close proximity to the axons. Such glial cells was found to have increased survival in compare to more distant ones from the axons under oxidative stress. The obtained data indicate that the crayfish giant axons have glia protective properties, which molecular mechanisms have to be studied.

  20. Identification and differential expression of hepatopancreas microRNAs in red swamp crayfish fed with emodin diet.

    PubMed

    Xu, Wei-Na; Liu, Wen-Bin; Yang, Wei-Wei; Zhang, Ding-Dong; Jiang, Guang-Zhen

    2014-07-01

    Using high-throughput Illumina Solexa system,