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thermodynamics of oxygenation-linked proton and lactate binding govern the temperature sensitivity of o2 binding in crustacean (carcinus maenas) hemocyanin.with the aim of understanding the molecular underpinnings of the enormous variation in the temperature sensitivity of hemocyanin-o2 affinity encountered in crustaceans, we measured o2 binding to carcinus maenas hemocyanin at two temperatures, varying ph values and in the absence and presence of lactate ions in order to assess the contributions of oxygenation-linked binding of protons (the bohr effect) and lactate ions to the overall enthalpies of oxygenation (deltah'). the hemocyanin binds maxim ...200818344479
crustin expression following bacterial injection and temperature change in the shore crab, carcinus maenas.the expression of carcinin, a crustin-type antimicrobial protein, in the crab, carcinus maenas, was studied following in vivo challenge with planococcus citreus, a gram-positive bacterium known to be killed by the encoded protein. real-time pcr analyses reveal that injection of p. citreus failed to elicit any significant changes in expression at 0-24h post-injection although there was a small, but significant, down-regulation at 84h in crabs held at 15 degrees c but not those at 5 or 20 degrees ...200818343497
identification of putative crustacean neuropeptides using in silico analyses of publicly accessible expressed sequence tags.the development of expressed sequence tags (ests) for crustacean cdna libraries and their deposition in publicly accessible databases has generated a rich resource for peptide discovery in this commercially and ecologically important arthropod subphylum. here, we have conducted in silico searches of these databases for unannotated ests encoding putative neuropeptide precursors using the blast program tblastn, and have predicted the mature forms of the peptides encoded by them. the primary strate ...200818321503
accumulation and histopathological damage in the clam ruditapes philippinarum and the crab carcinus maenas to assess sediment toxicity in spanish ports.the degree of contamination and toxicity in sediment from four spanish ports (cádiz, huelva, pasajes and bilbao) was assessed in the present study. two marine invertebrate species, the shore crab carcinus maenas and the clam ruditapes philippinarum, were exposed to the different sediments under laboratory conditions for 28 days. relationships were developed among metal contamination (as, cd, cr, cu, fe, hg, mn, ni, pb and zn) in sediments, metal accumulation in gill tissues and histopathological ...200818313100
differential snail predation by an exotic crab and the geography of shell-claw covariance in the northwest atlantic.here we investigate if predation by the european green crab (carcinus maenas) differs between two congeneric snails in the northwest atlantic (littorina littorea and l. obtusata), and ask if differential predation can help explain the geography of claw and shell forms among geographically separated populations. first, correlations between crusher-claw size and shell mass -- tested across a wide size range of animals -- were highly significant among populations of c. maenas and l. obtusata, where ...200818298647
species invasion shifts the importance of predator dependence.the strength of interference between foraging individuals can influence per capita consumption rates, with important consequences for predator and prey populations and system stability. here we demonstrate how the replacement of a previously established invader, the predatory crab carcinus maenas, by the recently invading predatory crab hemigrapsus sanguineus shifts predation from a species that experiences strong predator interference (strong predator dependence) to one that experiences weak pr ...200718229836
identification and developmental expression of mrnas encoding putative insect cuticle hardening hormone, bursicon in the green shore crab carcinus maenas.bursicon is the ultimate hormone in insect ecdysis, which is involved in cuticle hardening. here we show that mrnas encoding the heterodimeric cystine knot protein bursicon (burs alpha, beta), are present in crustaceans, suggesting ubiquity of this hormone in arthropods. we firstly report the cloning, sequencing of mrnas encoding subunits from the water flea, daphnia arenata and the cns of the crab, carcinus maenas, in comparison with insect bursicon subunits. expression patterns of alpha and be ...200818221939
effects of 4-nonylphenol on the endocrine system of the shore crab, carcinus maenas.there is a considerable body of evidence to suggest that many anthropogenic chemicals, most notably xeno-estrogens, are able to disrupt the endocrine system of vertebrates. there have been few comparable studies on the effects of exposure to these chemicals that may serve as biomarkers of endocrine disruption in aquatic invertebrate species. in addition, the evidence available is complex, conflicting, and far from conclusive. the present study aimed to investigate the impact of the xeno-estrogen ...200818214899
the role of biomarkers to assess oil-contaminated sediment quality using toxicity tests with clams and crabs.a 28-d bioassay was conducted with two invertebrate species with different feeding habits, the clam ruditapes philippinarum and the shore crab carcinus maenas. the purpose of the present study was to assess the quality of sediments affected by oil spills in different areas of the spanish coast. the organisms were exposed to environmental samples of oil-contaminated sediments during four weeks and, after the experiment, a suite of biomarkers of exposure was measured: the phase one detoxification ...200818198936
inhibition between invasives: a newly introduced predator moderates the impacts of a previously established invasive predator.1. with continued globalization, species are being transported and introduced into novel habitats at an accelerating rate. interactions between invasive species may provide important mechanisms that moderate their impacts on native species. 2. the european green crab carcinus maenas is an aggressive predator that was introduced to the east coast of north america in the mid-1800 s and is capable of rapid consumption of bivalve prey. a newer invasive predator, the asian shore crab hemigrapsus sang ...200818177327
skeletal adaptations for forwards and sideways walking in three species of decapod crustaceans.crustaceans have been successfully employed to study legged locomotion for decades. most studies have focused on either forwards-walking macrurans, or sideways-walking brachyurans. libinia emarginata is a majoid crab (brachyura) and as such belongs to the earliest group to have evolved the crab form from homoloid ancestors. unlike most brachyurans, libinia walks forwards 80% of the time. we employed standard anatomical techniques and motion analysis to compare the skeleton, stance, and the range ...200818089130
molt-inhibiting hormone immunoreactive neurons in the eyestalk neuroendocrine system of the blue crab, callinectes sapidus.the production of ecdysteroid molting hormones by crustacean y-organs is negatively regulated by a neuropeptide, molt-inhibiting hormone. it is generally agreed that molt-inhibiting hormone is produced and released by the eyestalk neuroendocrine system. in the present study, immunocytochemical methods were used to detect molt-inhibiting hormone immunoreactive neurons in eyestalk ganglia of the blue crab, callinectes sapidus. the primary antiserum used was generated against molt-inhibiting hormon ...200118088946
accumulation and depuration of okadaic acid esters in the european green crab (carcinus maenas) during a feeding study.soft shell crab is a seafood delicacy in many parts of the world. in denmark, it has been investigated whether a commercial production of soft shell european green crabs (carcinus maenas) would be feasible. in relation to this, a feeding study was performed to examine if occurrence of dsp toxins in the product could be a food safety problem. the crabs were fed with mussels containing dsp toxins (2500 microg total okadaic acid equivalents/kg) for 17 days and then fasted for 19 days. the content o ...200817983637
influence of predator density on nonindependent effects of multiple predator species.interactions between multiple predator species are frequent in natural communities and can have important implications for shared prey survival. predator density may be an important component of these interactions between predator species, as the frequency of interactions between species is largely determined by species density. here we experimentally examine the importance of predator density for interactions between predator species and subsequent impacts on prey. we show that aggressive inter ...200817968591
structural confirmation and occurrence of azaspiracids in scandinavian brown crabs (cancer pagurus).in 2005 and 2006, azaspiracids were for the first time detected in brown crabs (cancer pagurus) from the west coast of sweden and the north and north-west coast of norway. azaspiracids are marine toxins that have been detected in blue mussels in europe in recent years. on some occasions, they have been responsible for human intoxications with symptoms similar to those occurring by consumption of shellfish contaminated with okadaic acid group toxins. while the latter toxin group has been reported ...200817936866
a novel bacterial disease of the european shore crab, carcinus maenas molecular pathology and epidemiology.several rickettsia-like diseases have been reported in arthropods (insects and crustaceans), some of which result in significant losses of economically important species such as shrimp and crabs. this study reports on the molecular pathology of a recently emerged disease of the european shore crab, carcinus maenas, termed milky disease - named as a result of the unusual milky appearance of the haemolymph (blood). this disease was more prevalent (>26 %) during summer months when the water tempera ...200717768229
molecular cloning of crustins from the hemocytes of brazilian penaeid shrimps.crustins are antimicrobial peptides initially identified in the hemocytes of the crab carcinus maenas (11.5-kda peptide or carcinin) and recently also recognized in penaeid shrimps and other crustacean species. the aim of this study was to identify sequences encoding for crustins from the hemocytes of four brazilian penaeid species: farfantepenaeus paulensis, farfantepenaeus subtilis, farfantepenaeus brasiliensis and litopenaeus schmitti. using primers based on consensus nucleotide alignment of ...200717697082
crustacean hyperglycemic hormone from the tropical land crab, gecarcinus lateralis: cloning, isoforms, and tissue expression.crustacean hyperglycemic hormone (chh) regulates carbohydrate metabolism, molting, and ion and water transport. cdnas encoding four chh isoforms (designated eg-chh-a, -b, -c, and -d) were cloned from eyestalk ganglia (eg) from land crab, gecarcinus lateralis. the isoforms differed in the 3' region of the open reading frame and/or the length of the 3' untranslated region. all encoded essentially identical preprohormones containing a 28-amino acid (aa) signal peptide, a 42-aa precursor related pep ...201117586505
field validation of a battery of biomarkers to assess sediment quality in spanish ports.two marine invertebrates, the crab carcinus maenas and the clam ruditapes philippinarum, were used as bioindicator species to assess contamination when exposed in situ to sediment from different sites from four spanish ports cadiz (sw spain), huelva (sw spain), bilbao (ne spain) and pasajes (ne spain). in an attempt to determine sediments toxicity, a combination of exposure biomarkers was analyzed in both species: metallothionein-like-proteins (mtlps), ethoxyresorufin o-deethylase (erod), glutat ...200817582664
sex-specific mediation of foraging in the shore crab, carcinus maenas.experiments were conducted to investigate the sex-specific differences to feeding responses of the shore crab carcinus maenas throughout the year. results demonstrate that female shore crabs exhibit stronger feeding responses than males throughout the year with a significantly reduced feeding response in males during the summer months' reproductive season. we also studied the possible function(s) of the moulting hormone, 20-hydroxyecdysone (crustecdysone) that has been described as a potential f ...200717540370
clarification of cercaria sevillana (digenea: microphallidae) life cycle using morphological and molecular data.cercaria sevillana is the cercaria larval stage that infects the gonads and the digestive gland of its first intermediate host, nassarius reticulatus. in this study the decapodous crustacean carcinus maenas was used to determine if it would serve as second intermediate host in the parasite's life cycle. the latter hypothesis was based on the knowledge that c. maenas is the second intermediate host of several other digenean species. after dissection, it was possible to observe encysted metacercar ...200717539414
regulation of intertidal food webs by avian predators on new england rocky shores.although there is a large body of research on food webs in rocky intertidal communities, most of the emphasis has been on the marine benthic components. effects of avian predation on highly mobile predators such as crabs, remains practically unstudied in rocky shore ecosystems. the crab, cancer borealis, is an important component of the diet of gulls (larus marinus, l. argentatus) at the isles of shoals, maine, usa. c. borealis prey include the predatory gastropod nucella lapillus l., the herbiv ...200717536702
biomarkers study for sediment quality assessment in spanish ports using the crab carcinus maenas and the clam ruditapes philippinarum.intermolt crab carcinus maenas and clam ruditapes philippinarum were used to determine the toxicity of sediments collected in four spanish ports (cádiz, huelva, pasajes, and bilbao) under laboratory conditions during 28 days. sediment samples were analyzed to determine chemical concentration of metals (as, cd, cr, cu, fe, hg, mn, ni, pb, and zn), polyaromatic hydrocarbons, polychlorinated biphenyls, grain size distribution, and organic matter content. different biomarkers of exposure of early bi ...200717502980
mechanism of a plastic phenotypic response: predator-induced shell thickening in the intertidal gastropod littorina obtusata.phenotypic plasticity has been the object of considerable interest over the past several decades, but in few cases are mechanisms underlying plastic responses well understood. for example, it is unclear whether predator-induced changes in gastropod shell morphology represent an active physiological response or a by-product of reduced feeding. we address this question by manipulating feeding and growth of intertidal snails, littorina obtusata, using two approaches: (i) exposure to predation cues ...200717465912
molecular characterization and cell-specific expression of an ion transport peptide in the tobacco hornworm, manduca sexta.the crustacean hyperglycemic hormone (chh) peptides regulate diverse physiological processes from reproduction to metabolism and molting in arthropods. in insects, the ion transport peptides (itp), also members of the chh family, have only been implicated in ion transport. in this study, we sequenced a nucleotide fragment spanning the conserved a1/a2 region of the putative chh/itp gene. this fragment was amplified from larval cdna of the tobacco hornworm, manduca sexta and showed a high degree o ...200717450383
antilipopolysaccharide factor (alf) of mud crab scylla paramamosain: molecular cloning, genomic organization and the antimicrobial activity of its synthetic lps binding domain.antilipopolysaccharide factors (alfs) are small basic proteins that can bind and neutralize lipopolysaccharide (lps) and have broad spectrum antimicrobial activities. in this study, we describe the isolation of the full-length cdna encoding for alf peptide (alfsp) of mud crab, scylla paramamosain by sequencing a hemocyte cdna library and using the rapid amplification cdna end (race) method. a full-length alfsp cdna of 614 bp contains an open reading frame (orf) of 372 bp, encoding 123 amino acid ...200717368541
the effect of dietary chitin supplementation on the survival and immune reactivity of the shore crab, carcinus maenas.adult male shore crabs (carcinus maenas) were maintained on a fish-based diet supplemented with 0, 5 or 10% chitin for 11 weeks. significantly greater mortality was found during this period in the control group (0% chitin) than those fed 10% chitin. crabs fed 5 or 10% chitin had lower numbers of cultivatable bacteria in the hepatopancreas than those on the basal diet alone. the addition of chitin had no significant effect on the serum concentrations of protein and glucose, and the levels of glyc ...200717289410
an experimental evaluation of host specificity: the role of encounter and compatibility filters for a rhizocephalan parasite of crabs.the encounter/compatibility paradigm of host specificity provides three qualitative pathways to the success or failure of a potential host-parasite interaction. it is usually impossible to distinguish between two of these (encounter and compatibility filters closed versus encounter filter open and compatibility filter closed) because unsuccessful infection attempts are difficult to observe in nature. we were able to open the encounter filter under experimental laboratory conditions. our analytic ...200717275825
the use of a metallothionein-like-proteins (mtlp) kinetic approach for metal bioavailability monitoring in dredged material.ecotoxicological effects associated with contaminants present in dredged material from spain were determined using a marine biotest based on the determination of metallothionein-like-protein concentrations (mtlps) in the shore crab carcinus maenas. intermoult female c. maenas were exposed in the laboratory to sediments from three spanish ports, ría de huelva (sw, spain), la coruña (nw, spain) and bahía de cádiz (sw, spain) per replicate during 21 days. hepatopancreas samples from crabs were take ...200717218013
effect of temperature on the spoilage rate of whole, unprocessed crabs: carcinus maenas, necora puber and cancer pagurus.shelf life of whole, initially live, crabs depended primarily on the storage conditions and the time at which death occurred. large differences in the time that individual crab species survived particular storage conditions resulted in wide variations in shelf-life. bacterial spoilage of carcinus maenas, necora puber and cancer pagurus, measured using aerobic plate counts, indicated that on ice at 4 degrees c whole unprocessed crabs had a shelf life approximately 9-11 days, at 4 degrees c approx ...200717189768
herbivore-induced infochemicals influence foraging behaviour in two intertidal predators.herbivore-induced defences appear ubiquitous across most biomes and habitats. yet the direct correlation between induced changes in host plant chemistry and the population dynamics of the herbivore remain untested in many systems. in plant-herbivore interactions in the terrestrial environment, indirect or tritrophic interactions appear a successful way in which changes in the host plant chemistry induced by prior herbivory can impact on herbivore populations via increased success of natural enem ...200717106720
molt-inhibiting hormone from the tropical land crab, gecarcinus lateralis: cloning, tissue expression, and expression of biologically active recombinant peptide in yeast.molt-inhibiting hormone (mih), a member of the crustacean hyperglycemic neuropeptide hormone family, inhibits ecdysteroidogenesis in the molting gland or y-organ (yo). a cdna encoding mih of the land crab (gel-mih) was cloned from eyestalk ganglia (eg) by a combination of reverse transcriptase polymerase chain reaction (rt-pcr) and 3'- and 5'-rapid amplification of cdna ends (race). the cdna (1.4 kb) encoded mih prohormone containing a 35 amino acid signal peptide and a 78 amino acid mature pept ...200717094991
intermoult duration affects the susceptibility of shore crabs carcinus maenas (l.) to pyrene and their ability to metabolise it.we have studied pyrene (pyr) toxicity and the ability to metabolise and eliminate pyr in two colour forms of shore crabs carcinus maenas (linnaeus, 1758). in addition, we analysed differences in the expression of expressed sequence tags (ests) encoding specific cytochrome p450s (cyps) by quantitative realtime pcr. green and red intermoult crabs are considered to represent different adaptational life stages, allocating energy into growth (green) and reproduction (red), respectively. pyr injection ...200617056131
habitat effects on the relative importance of trait- and density-mediated indirect interactions.classical views of trophic cascades emphasize the primacy of consumptive predator effects on prey populations to the transmission of indirect effects [density-mediated indirect interactions (dmiis)]. however, trophic cascades can also emerge without changes in the density of interacting species because of non-consumptive predator effects on prey traits such as foraging behaviour [trait-mediated indirect interactions (tmiis)]. although ecologists appreciate this point, measurements of the relativ ...200617040327
an oxygenation-sensitive dye binding to carcinus maenas hemocyanin.the interaction of 4',6-diamidino-2-phenylindole (dapi) with carcinus maenas hemocyanin has been investigated by steady state fluorescence, dynamic fluorescence and circular dichroism measurements. the dye binds to apohemocyanin (without copper) as well as to oxygenated hemocyanin and to deoxygenated hemocyanin with very similar affinities (kd approximately equal to 1 microm ) and number of binding sites (one per subunit). in contrast, the fluorescence quantum yield enhancement of dapi bound to ...199417020829
intraguild predation reduces redundancy of predator species in multiple predator assemblage.1. interference between predator species frequently decreases predation rates, lowering the risk of predation for shared prey. however, such interference can also occur between conspecific predators. 2. therefore, to understand the importance of predator biodiversity and the degree that predator species can be considered functionally interchangeable, we determined the degree of additivity and redundancy of predators in multiple- and single-species combinations. 3. we show that interference betwe ...200617009759
the effect of magnesium deficiency on neuro-muscular transmission in the shore crab carcinus maenas. 194616991693
identification and developmental expression of mrnas encoding crustacean cardioactive peptide (ccap) in decapod crustaceans.full-length cdnas encoding crustacean cardioactive peptide (ccap) were isolated from several decapod (brachyuran and astacuran) crustaceans: the blue crab callinectes sapidus, green shore crab carcinus maenas, european lobster homarus gamarus and calico crayfish orconectes immunis. the cdnas encode open reading frames of 143 (brachyurans) and 139-140 (astacurans) amino acids. apart from the predicted signal peptides (30-32 amino acids), the conceptually translated precursor codes for a single co ...200616985202
diluting the founder effect: cryptic invasions expand a marine invader's range.most invasion histories include an estimated arrival time, followed by range expansion. yet, such linear progression may not tell the entire story. the european green crab (carcinus maenas) was first recorded in the us in 1817, followed by an episodic expansion of range to the north. its population has recently exploded in the canadian maritimes. although it has been suggested that this northern expansion is the result of warming sea temperatures or cold-water adaptation, canadian populations ha ...200616959635
enzymatic biomarkers in the crab carcinus maenas from the minho river estuary (nw portugal) exposed to zinc and mercury.zinc and mercury are common contaminants of estuaries and coastal ecosystems where they may induce adverse effects on the biota. carcinus maenas is a key-species in several european estuaries, living in close association with the sediment where a considerable number of environmental contaminants, including zinc and mercury may accumulate. in the present study, the acute effects of zinc and mercury on c. maenas from the minho river estuary (nw portugal) were investigated by using the activity of ...200716949639
copper reduced mating behaviour in male shore crabs (carcinus maenas (l.)).many crustaceans use pheromones to find mates and induce mating behaviours. if pollutants impair the ability to detect chemosensory cues and respond to pheromone signals, they could profoundly affect mating. in a series of laboratory experiments, the effect of copper (0, 0.1 or 0.5 mg cu(ii) per litre for 5 days) on specific components of the mating behaviour of male shore crab carcinus maenas was investigated, as well as differences in sensitivity between red and green colour morphs. the result ...200616942808
divergent induced responses to an invasive predator in marine mussel populations.invasive species may precipitate evolutionary change in invaded communities. in southern new england (usa) the invasive asian shore crab, hemigrapsus sanguineus, preys on mussels (mytlius edulis), but the crab has not yet invaded northern new england. we show that southern new england mussels express inducible shell thickening when exposed to waterborne cues from hemigrapsus, whereas naïve northern mussel populations do not respond. yet, both populations thicken their shells in response to a lon ...200616902136
seasonal fluctuations of tissue mercury contents in the european shore crab carcinus maenas from low and high contamination areas (ria de aveiro, portugal).the main objective was to study the seasonal variation of mercury concentrations in different tissues (muscle, hepatopancreas and gills) of carcinus maenas from low and high hg contaminated areas, a valuable resource in temperate estuaries and a possible pathway for human uptake. individuals of two size classes (around 35 and 55 mm cephalothorax wide) were captured monthly between march 1999 and may 2000 in two areas of ria de aveiro: in the main navigation channel that connects the lagoon to th ...200616824552
signaled avoidance in the eye withdrawal reflex of the green crab.learning in a signaled avoidance procedure was studied in the eye withdrawal reflex of the green crab, carcinus maenas. a puff of air to the eye, which causes eye retraction, was used as the unconditioned stimulus (us). a mild vibration on the carapace, which has no effect on untrained animals, was used as a warning (conditioned) stimulus (cs). eye withdrawal during the cs led to the omission of the otherwise scheduled us. acquisition was rapid, reaching about 75% avoidance after 30 trials. exti ...198816812569
neuroendocrine regulation of carbonic anhydrase expression in the gills of the euryhaline green crab, carcinus maenas.the relationship between branchial carbonic anhydrase (ca) activity, ca gene expression and salinity, and potential mechanisms of regulation, was investigated in the euryhaline green crab, carcinus maenas, acclimated to 33 ppt and transferred to 10 ppt, and the stenohaline rock crab, cancer irroratus, acclimated to 32 ppt and transferred to 18 ppt. ca activity in green crabs acclimated to high and low salinity was a function of ca mrna expression, with low salinity exposure resulting in an incre ...200616788899
functional evidence for the presence of a carbonic anhydrase repressor in the eyestalk of the euryhaline green crab carcinus maenas.carbonic anhydrase (ca) activity and relative expression of ca mrna were measured in the gills of the euryhaline green crab carcinus maenas in response to eyestalk ablation (esa), injection of eyestalk extract and exposure to low salinity. for crabs acclimated to 32 p.p.t. salinity, esa alone resulted in an increase in both ca activity and relative mrna expression in the posterior, ion-transporting gills, but not in the anterior, respiratory gills. the esa-stimulated increase in ca activity was ...200616788042
neuromodulation of spike-timing precision in sensory neurons.the neuropeptide allatostatin decreases the spike rate in response to time-varying stretches of two different crustacean mechanoreceptors, the gastropyloric receptor 2 in the crab cancer borealis and the coxobasal chordotonal organ (cbcto) in the crab carcinus maenas. in each system, the decrease in firing rate is accompanied by an increase in the timing precision of spikes triggered by discrete temporal features in the stimulus. this was quantified by calculating the standard deviation or "jitt ...200616738233
quantitative changes in branchial carbonic anhydrase activity and expression in the euryhaline green crab, carcinus maenas, in response to low salinity exposure.hemolymph osmolality, and changes in gill carbonic anhydrase (ca) activity, relative mrna expression, and ca protein concentration were measured in the green crab carcinus maenas acclimated to 32 ppt salinity and transferred to 10 ppt. hemolymph osomolality stabilized at new, acclimated values, by 24 hr after transfer. there was a large increase in ca mrna concentrations, as measured by quantitative pcr, in the posterior gills by 24 hr post-transfer that remained elevated through 4 days. by 7 da ...200616736501
molecular detection of hematodinium spp. in norway lobster nephrops norvegicus and other crustaceans.the norway lobster nephrops norvegicus (l.) from the coastal waters of scotland is seasonally infected by a parasitic dinoflagellate of the genus hematodinium. methods used to detect infection include a morphological index (pleopod diagnosis) and several immunoassays. the present study describes the development and application of a set of hematodinium-specific polymerase chain reaction (pcr) primers and dna probes based on hematodinium ribosomal dna (rdna). in the pcr assay, a diagnostic band of ...200616724562
gene characterisation, isoforms and recombinant expression of carcinin, an antibacterial protein from the shore crab, carcinus maenas.carcinin is a whey acidic protein (wap) domain-containing antimicrobial protein produced by the circulating haemocytes of the shore crab, carcinus maenas. cloning of its full coding cdna reveals that it shows some similarity to invertebrate defensins, has a valine-rich signal sequence followed by a defined cleavage site but no obvious acidic anionic 'pro' sequence. the c-terminus exhibits a unique cysteine array that is predicted to form six disulphide bonds in the tertiary structure. this 12 cy ...200716712935
the effects of temperature on peripheral neuronal function in eurythermal and stenothermal crustaceans.to determine whether neuronal function in antarctic crustaceans is adapted to the low and narrow range of temperatures at which these animals live, we have compared conduction velocities in the peripheral nervous systems of two temperate species, the decapod carcinus maenas and the isopod ligia oceanica, and two antarctic species, the isopod glyptonotus antarcticus and the amphipod paraceradocus gibber. neuronal conduction velocity differs among the species in the order c. maenas > g. antarcticu ...200616651562
the beep stavanger workshop: mesocosm exposures.within the beep project (biological effects of environmental pollution in marine ecosystems) the work package 1 was addressed to the development of new and more sensitive biomarkers of exposure in several sentinel organisms. within this framework, common mesocosm exposures of organic pollutants relevant for marine ecosystems were conducted in the facilities of akvamiljø a/s (stavanger, norway). in the first experiment, atlantic cod (gadus morhua), turbot (scophthalmus maximus) and shore crab (ca ...200616635530
unusual cardioactive peptide (ccap) from pericardial organs of the shore crab carcinus maenas.an unusual crustacean cardioactive peptide (ccap) from the pericardial organs of the shore crab carcinus maenas has been purified to homogeneity by a two-step reversed-phase hplc procedure. manual microsequencing using the 4-(n,n-dimethylamino)azobenzene 4'-isothiocyanate/phenylisothiocyanate double-coupling technique and automated gas-phase sequencing of the oxidized peptide revealed that ccap is a nonapeptide (m(r) 957) of the sequence pro-phe-[unk]cys-asn-ala-phe-thr-gly-cys-nh(2). we have co ...198716593803
intense natural selection caused a rapid morphological transition in a living marine snail.shell shape and shell thickness of the intertidal snail littorina obtusata changed markedly between 1871 and 1984 in northern new england. shells collected prior to 1900 were high-spired with thin walls, whereas shells collected in 1982-84 were low-spired with thick walls. an intertidal crab (carcinus maenas) which preys on l. obtusata expanded its range into northern new england around 1900. this suggests that the change in snail shell form was a response to predation by carcinus. field and lab ...198616593760
transmissible disease, probably viral in origin, affecting the amebocytes of the european shore crab, carcinus maenas.a transmissible infection of the shore crab ("crabe enragée"), carcinus maenas, was discovered in one of about 700 of this species collected by the station biologique, roscoff, france. the infection has been transferred by subinoculation through four serial passages in crabs collected at roscoff and through six more passages in c. maenas collected at woods hole, mass. the agent causes abnormal cellular clotting, a drop in the peripheral amebocyte count, clumping of amebocytes in the peripheral t ...197116558026
binding sites of crustacean hyperglycemic hormone and its second messengers on gills and hindgut of the green shore crab, carcinus maenas: a possible osmoregulatory role.to determine the possible involvement of crustacean hyperglycemic hormone (chh) in osmoregulation in crustaceans, ligand binding and second messenger assays were performed on gills and hindgut preparations of the green shore crab carcinus maenas, whilst midgut gland, previously known as one of the target tissues of chh served as a control tissue. classical receptor binding analyses using [(125)i]chh by saturation and displacement experiments from membrane preparations from gills, hindgut, and mi ...200616504184
the effect of seawater composition and osmolality on hemolymph levels of methyl farnesoate in the green crab carcinus maenas.green crabs, carcinus maenas, exposed to dilute seawater (e.g., 5 ppt salinity, approximately 150 mosm/kg) have hemolymph levels of methyl farnesoate (mf) that are up to 10-fold higher than animals in isosmotic seawater (27 ppt, approximately 800 mosm/kg). in this paper, we examine aspects of osmotic and ionic stress to identify factors involved in elevating mf levels. mf levels did not rise after exposure to concentrated seawater, so only hypoosmotic stress elevates mf. mf levels rose in animal ...200616352450
primer and short-range releaser pheromone properties of premolt female urine from the shore crab carcinus maenas.the european shore crab carcinus maenas is considered to rely on a female pheromone when mating. evidence, however, is scarce on how the urine pheromone in itself affects males. we investigated male primer and releaser responses to female pheromones with methods that minimized effects from females, delivering female urine either as a pump-generated plume or deposited on a polyurethane sponge. we delivered the pheromone at different concentrations in far, near, and close/contact range to get a pi ...200516222811
a study of the mechanisms by which the cercariae of microphallus primas (jag, 1909) stunkard, 1957 penetrate the shore crab, carcinus maenas (l).this study established the mechanisms by which microphallus primas cercariae penetrate the crab carcinus maenas in which they form metacercarial cysts. light and electron microscopy were used to investigate cercarial features and to follow the fate of cercariae released in close proximity to crabs. it was shown that cercariae were carried in respiratory currents into crabs' branchial chambers where each enveloped itself in a transparent penetration cyst on the gill lamellae. when cercariae were ...200516174417
disposition of polychlorinated dibenzo-p-dioxins (pcdds) and polychlorinated dibenzofurans (pcdfs) in two norwegian epibenthic marine food webs.polychlorinated dibenzo-p-dioxins (pcdds) and dibenzofurans (pcdfs) are a group of halogenated hydrocarbons, comprising 210 different, theoretically possible congeners. they are relatively hydrophobic and persistent to biodegradation, thereby rendering them subject to bioaccumulation. this study was conducted in frierfjord and eidangerfjord in the grenland fjord system, norway, heavily polluted by pcdd/pcdf discharges from the 16,600,859 magnesium production at herøya from 1951 to 2001. pooled s ...200616169571
dynamics of in vivo release of molt-inhibiting hormone and crustacean hyperglycemic hormone in the shore crab, carcinus maenas.very little is known regarding the release patterns or circulating titers of neuropeptides in crustaceans, in particular those concerned with regulation of molting hormone (ecdysteroid) synthesis, molt-inhibiting hormone (mih), and crustacean hyperglycemic hormone (chh), which is also an adaptive hormone, centrally important in carbohydrate metabolism. furthermore, the currently accepted model of molt control is founded on an untested hypothesis suggesting that molting can proceed only after dec ...200516150903
cloning of a crustin-like, single whey-acidic-domain, antibacterial peptide from the haemocytes of the european lobster, homarus gammarus, and its response to infection with bacteria.degenerate pcr was used to isolate a 221-base pair nucleotide sequence of a new crustin-like antibacterial peptide from the haemocytes of the european lobster, homarus gammarus. rapid amplification of cdna ends was used to extend the sequence to determine the complete open reading frame and un-translated regions. the inferred amino acid sequence of this peptide was found to be similar to crustin-like peptides isolated for several species of shrimp as well as the shore crab, carcinus maenas. the ...200616144710
partitioning mechanisms of predator interference in different habitats.prey are often consumed by multiple predator species. predation rates on shared prey species measured in isolation often do not combine additively due to interference or facilitation among the predator species. furthermore, the strength of predator interactions and resulting prey mortality may change with habitat type. we experimentally examined predation on amphipods in rock and algal habitats by two species of intertidal crabs, hemigrapsus sanguineus (top predators) and carcinus maenas (interm ...200616086166
an in situ postexposure feeding assay with carcinus maenas for estuarine sediment-overlying water toxicity evaluations.this study developed and evaluated a short-term sublethal in situ toxicity assay for estuarine sediment-overlying waters, with the crab carcinus maenas (l.) based on postexposure feeding. it consisted of a 48-h in situ exposure period followed by a short postexposure feeding period (30 min). a precise method for quantifying feeding, using the polychaeta hediste (nereis) diversicolor müller as food source, was first developed. the sensitivity of the postexposure feeding response was verified by c ...200616002194
range extension of two invasive crab species in eastern australia: carcinus maenas (linnaeus) and pyromaia tuberculata (lockington). 200515823308
inter-population variability in the reproductive morphology of the shore crab (carcinus maenas): evidence of endocrine disruption in a marine crustacean?environmental contaminants that are capable of causing endocrine disrupting effects are currently a major cause for concern. these chemicals are known to influence the reproductive development of vertebrates by mimicking or antagonising the actions of endogenous hormones. however, little is known regarding their potential effects on invertebrates. here we examine variations in the reproductive morphology of the shore crab (carcinus maenas) for evidence of endocrine disruption. crabs were collect ...200415823302
a histopathological survey of shore crab (carcinus maenas) and brown shrimp (crangon crangon) from six estuaries in the united kingdom.invertebrates show considerable potential as sentinel organisms for the monitoring of the health status of aquatic systems. they are generally small, abundant, relatively sessile, and may readily bioaccumulate toxins. cascade-like stress responses can occur following acute or chronic exposures to contaminated environments and as such, the overall health status of individuals within those environments, both in terms of histopathological lesions and the presence of infecting organisms, may ultimat ...200515766930
cadmium, zinc and the uptake of calcium by two crabs, carcinus maenas and eriocheir sinensis.the uptake of dissolved cadmium and zinc by crustaceans can usually be explained by the passive process of facilitated diffusion involving a transport protein in the membranes of permeable surfaces. cadmium ions will also enter via uptake routes for calcium, given the similar size of the two free ions. this study has investigated the interaction of cadmium (and comparatively zinc) and calcium uptake in two crabs that show different permeability responses to changes in salinity, with consequently ...200515748747
in vivo and in vitro cadmium accumulation during the moult cycle of the male shore crab carcinus maenas--interaction with calcium metabolism.the effect of moult stage on cadmium accumulation and distribution was investigated in vivo in male shore crabs carcinus maenas exposed to 1 mg cd l(-1) for 7 days. the accumulation of cadmium in all tissues examined was markedly higher in postmoult (a(1-2) and b(1-2)) compared to intermoult (c1, c3 and c4) and premoult (d(0-3)). in addition, elevated levels of cadmium were found in gills of late premoult (d(2-3)) animals. the total amount of cadmium accumulated in the tissues (haemolymph, gills ...200515748746
association between cadmium and calcium uptake and distribution during the moult cycle of female shore crabs, carcinus maenas: an in vivo study.net influxes into the haemolymph and tissue distribution of 45ca and 109cd were studied in vivo in female carcinus maenas at different moult stages. net influxes of 45ca and 109cd from water were higher in postmoult (a and b) c. maenas than in c3- and c4-intermoult crabs and the net influx of calcium was higher in c3-intermoult crabs than in c4-intermoult crabs. the net influxes of 45ca and 109cd increased in postmoult c. maenas with decreasing external calcium concentrations at constant salinit ...200515748745
cadmium in the shore crab carcinus maenas: seasonal variation in cadmium content and uptake and elimination of cadmium after administration via food.the uptake and assimilation efficiency of cadmium administered via the food in the shore crab carcinus maenas were investigated together with elimination kinetics and seasonal variations in cadmium content. the majority of shore crabs assimilated between 41 and 86% of the cadmium administered in their food. more than 90% of the cadmium taken up from food was retained in midgut gland. elimination of cadmium after uptake from one meal of radioactively labelled soft parts of blue mussels could be d ...200515748744
dietary preference and digestive enzyme activities as indicators of trophic resource utilization by six species of crab.the digestive physiology and stomach contents of six crab species from a variety of habitats were investigated to provide an indication of their digestive capability and dietary preferences. stomach contents varied between species, but the key enzymes present were generally consistent with the types of dietary material being ingested. nectocarcinus integrifons (red rock crab) consumed large quantities of seagrass and had high cellulase activity (0.02+/-0.004 units mg-1) to digest the constituent ...200515713811
influence of salinity in hemolymph vitellogenin of the shore crab carcinus maenas, to be used as a biomarker of contamination. 200415669731
an integrated approach using bioaccumulation and biomarker measurements in female shore crab, carcinus maenas.the shore crab carcinus maenas, was used as a biomonitoring organism to measure the potential impact that the mining spill in the guadalquivir estuary (sw, spain), in 1998 may have exerted on local biota. female intermoult c. maenas were exposed to dissolved cadmium, copper and zinc at concentrations found in local waters following the spill (3 microgl-1 cd, 15 microgl-1 cu, 700 microgl-1 zn). groups of shore crabs were exposed for 21 days to these metals, both singularly and in combination. res ...200515620755
critical salinity, sensitivity, and commitment of salinity-mediated carbonic anhydrase induction in the gills of two euryhaline species of decapod crustaceans.two euryhaline species of decapod crustaceans, carcinus maenas and callinectes sapidus, were subjected to a series of acute low-salinity challenges, and changes in carbonic anhydrase (ca) activity in the gills were monitored in order to characterize the nature of salinity-sensitive ca induction. ca activity is uniformly low in all gills of both species at high salinity, but at a critical salinity of 27 ppt, ca induction occurs in the posterior, ion-transporting gills, with ca activity approximat ...200515612006
ammonia excretion in aquatic and terrestrial crabs.the excretory transport of toxic ammonia across epithelia is not fully understood. this review presents data combined with models of ammonia excretion derived from studies on decapod crabs, with a view to providing new impetus to investigation of this essential issue. the majority of crabs preserve ammonotely regardless of their habitat, which varies from extreme hypersaline to freshwater aquatic environments, and ranges from transient air exposure to obligate air breathing. important components ...200415579545
influence of season and environment on adult neurogenesis in the central olfactory pathway of the shore crab, carcinus maenas.in most vertebrates hitherto examined including humans, certain brain areas retain the capacity to build new neurons during adult life. in some arthropods, above all in crustaceans, continuous genesis of brain neurons has also been shown, namely for soma clusters of the olfactory brain. several factors as, e.g., sensory input, living conditions, or stress, are known to influence the rate of cell proliferation, survival, and cell differentiation. the present study was undertaken to test whether s ...200415464748
investigations on cholinesterase in carcinus maenas. 194915394592
identification and quantification of n-octyl esters of alkanoic and hexanedioic acids and phthalates as urban wastewater markers in biota and sediments from estuarine areas.a gas chromatographic method for the identification and quantification of n-octyl esters (from n-octyl tetradecanoate to n-octyl hexa-cosanoate including dioctyl hexanedioate) and phthalates [dibutyl phthalate, benzyl butyl phthalate and di(2-ethylhexyl) phthalate] in sediments and biota from estuarine environments is described. standards used for identification and quantification of some n-octyl esters were synthesized. the method has allowed the analysis of these compounds in polychaeta (nerei ...200415387189
a global invader at home: population structure of the green crab, carcinus maenas, in europe.the european green crab, carcinus maenas, has a native distribution that extends from norway to mauritania. it has attracted attention because of its recent invasions of australia, tasmania, south africa, japan and both coasts of north america. to examine the population structure of this global invader in its native range, we analysed a 502-base-pair fragment of the mitochondrial cytochrome c oxidase i (coi) gene from 217 crabs collected in the north atlantic and 13 specimens from the mediterran ...200415367106
expression and release patterns of neuropeptides during embryonic development and hatching of the green shore crab, carcinus maenas.crustacean ecdysis is controlled by at least three neuropeptides: moult-inhibiting hormone (mih), which represses ecdysteroid synthesis; crustacean hyperglycaemic hormone (chh), which not only influences ecdysteroid synthesis but also water uptake during moulting; and crustacean cardioactive peptide (ccap), which is involved in stereotyped ecdysis behaviour. during embryonic development, moulting takes place in the egg, but there is little information regarding developmental expression of these ...200415329340
haemolymph parasite of the shore crab carcinus maenas: pathology, ultrastructure and observations on crustacean haplosporidians.a protozoan parasite with some features of haplosporidians is described from the european shore crab carcinus maenas. the parasite establishes a systemic infection through the haemal sinuses and connective tissues. intracellular stages of the parasite were found within reserve inclusion, connective tissue, and muscle cells, while free forms were present in all haemal spaces. a uninucleate stage appeared to develop to a multinucleate plasmodial stage following multiple mitotic divisions of the nu ...200415212293
urinary pah metabolites as biomarkers of exposure in aquatic environments.while immunoassays have been extensively applied to evaluate environmental contamination, to date they have rarely been used for the analysis of biological fluids outside of human medicine. these media are important because pollutants such as polycyclic aromatic hydrocarbons (pahs) and their metabolites become concentrated in tissues, body fluids, and excreta, thereby offering a measure of exposure to biologically available contaminants. such analyses also provide a nondestructive tool for monit ...200415180061
toxicokinetics of heavy metals from a mining spill using carcinus maenas.the knowledge of the reproduction and growth background related to the shore crab carcinus maenas promotes the use of this crab as a model crustacean to asses the potential for endocrine disruption in crustaceans. in addition, an enzyme linked inmunosorbent assay (elisa), sensitive to the shore crab vitellogenin in serial hemolymph samples allows determination of the extent of disruption of the process of vitellogenesis in female crabs and its likely impact on reproductive output. intermoult fem ...200415178121
temperature-dependent physiological response of carcinus maenas exposed to copper.the effect of temperature on the heart rate (fh) of carcinus maenas exposed to a sublethal nominal concentration (0.5 mg l(-1)) of copper is reported. adult, intermoult males (4 cm carapace width) were collected from stavanger fjord (norway) in august (seawater temperature=17 degrees c) and maintained in the laboratory (fed ad libitum) at 5, 15 and 25 degrees c for 7 days. following this holding period, crabs were exposed to waterborne copper at the same temperature. after 3 days of exposure, in ...200415178113
evaluation of fixed wavelength fluorescence and synchronous fluorescence spectrophotometry as a biomonitoring tool of environmental contamination.a field study was carried out to investigate whether polyaromatic hydrocarbon (pah) contamination in shore crabs (carcinus maenas) could be measured using fluorescence spectrometry. crabs were collected as part of an integrated study to assess pah contamination in southampton water, uk. urine was collected from crabs via a non-destructive technique and analysed using fixed wavelength fluorescence (ff) and synchronous fluorescence spectrophotometry (sfs) in order to determine the presence of pah ...201615178045
differential sensitivity of three marine invertebrates to copper assessed using multiple biomarkers.understanding how biomarkers relate to each other on exposure to particular contaminants in different species is key to their widespread application in environmental management. however, few studies have systematically used multiple biomarkers in more than a single species to determine the variability of sublethal effects of a particular contaminant. in this study, three marine invertebrates, the shore crab carcinus maenas, the common limpet patella vulgata and the blue mussel mytilus edulis, we ...200415129769
a multibiomarker approach to environmental assessment.incorporation of ecologically relevant biomarkers into routine environmental management programs has been advocated as a pragmatic means of linking environmental degradation with its causes. here, suites of biomarkers, devised to measure molecular damage, developmental abnormality and physiological impairment, were combined with chemical analysis to determine exposure to and the effects of pollution at sites within southampton water (uk). test species included a filter feeder, a grazer, and an o ...200415074681
histopathological effects of trypanorhynch metacestodes in the digestive gland of a novel host, carcinus maenas (decapoda).the green crab carcinus maenas was introduced to australian temperate waters in the late 1800s, has since become established, and is now considered to be a pest. we undertook an extensive parasite survey to find potential natural enemies of c. maenas and found it to be infected in australia by 2 species of larval trypanorhynch tapeworm, trimacracanthus aetobatidis and dollfusiella martini. we describe the gross pathology and histopathology of the parasites' new host (c. maenas) and note that the ...200415038453
rapid assessment of polycyclic aromatic hydrocarbon (pah) exposure in decapod crustaceans by fluorimetric analysis of urine and haemolymph.polycyclic aromatic hydrocarbons (pahs) are ubiquitous and potentially harmful contaminants of the coastal and marine environment. studies of their bioavailability, disposition and metabolism in marine organisms are therefore important for environmental monitoring purposes. detecting pah compounds in the biological fluids of marine organisms provides a measure of their environmental exposure to pahs. in the present study, the shore crab carcinus maenas was exposed to waterborne pyrene for 48h. u ...200415003698
crustins, homologues of an 11.5-kda antibacterial peptide, from two species of penaeid shrimp, litopenaeus vannamei and litopenaeus setiferus.the response of crustaceans to pathogens is believed to depend solely on innate, nonadaptive immune mechanisms, including phagocytosis, encapsulation, clotting, and a variety of soluble antimicrobial activities. arthropod antimicrobial peptides, while characterized primarily from insects, also have been isolated from crustaceans. expressed sequence tag analysis of hemocyte complementary dna libraries from 2 species of shrimp, litopenaeus vannamei and litopenaeus setiferus, revealed transcripts w ...200214961261
acetylcholine formation in the central nervous system of carcinus maenas. 195014770883
response in nematocyst uptake by the nudibranch flabellina verrucosa to the presence of various predators in the southern gulf of maine.aeolid nudibranchs maintain nematocysts sequestered from their cnidarian prey for protection against predators. selection for nematocyst incorporation is a function of diet and prey choice, but ratios vary among nudibranchs feeding on a given diet, indicating that other factors may be involved. it is proposed that the presence of predators influences nematocyst incorporation. nematocyst uptake in the nudibranch flabellina verrucosa collected from the southern gulf of maine was examined in respon ...200314672990
ontogeny of osmoregulatory structures and functions in the green crab carcinus maenas (crustacea, decapoda).the ontogeny of osmoregulation, the development of branchial transporting epithelia and the expression of the enzyme na+/k+-atpase were studied in carcinus maenas (l.) obtained from the north sea, germany. laboratory-reared zoea larvae, megalopae and young crabs were exposed to a wide range of salinities, and hemolymph osmolality was measured after 24 h exposure time (72 h in juveniles). zoea i larvae slightly hyper-regulated in dilute media (10.2 per thousand and 17.0 per thousand ) and osmocon ...200414668316
effect of low salinity on cadmium accumulation and calcium homeostasis in the shore crab (carcinus maenas) at fixed free cd2+ concentrations.increased cd toxicity at low salinity has been attributed to increased free cd2+ ion concentration ([cd2+]sw), but transfer to dilute seawater also stimulates physiological ionic regulation in crabs. in this study, cd accumulation and ca homeostasis in the shore crab (carcinus maenas) were explored at fixed [cd2+]sw to reveal the physiological events during sublethal cd exposure. crabs were exposed to 3.4 or 34 microg/l [cd2+], in both 100% seawater (sw) and 33% sw for up to 10 d and sampled for ...200314587919
cyp330a1 and cyp4c39 enzymes in the shore crab carcinus maenas: sequence and expression regulation by ecdysteroids and xenobiotics.cytochrome p450 enzymes (cyp enzymes) catalyse important metabolic reactions of exogenous and endogenous substrates, including steroid hormones. here, we report the first two cyp sequences from the shore crab, carcinus maenas. two complete cdnas isolated from crab hepatopancreas encode cyp enzymes named cyp330a1, the first member of a new family, and cyp4c39. cyp330a1 is closest related to members of the cyp2 family (37.3% identical to mouse cyp2j6) and cyp4c39 is most identical to crayfish cyp4 ...200314521903
salinity-mediated carbonic anhydrase induction in the gills of the euryhaline green crab, carcinus maenas.the euryhaline green crab, carcinus maenas, is a relatively strong osmotic and ionic regulator, being able to maintain its hemolymph osmolality as much as 300 mosm higher than that in the medium when the crab is acclimated to low salinity. it makes the transition from osmoconformity to osmoregulation at a critical salinity of 26 ppt, and new acclimated concentrations of hemolymph osmotic and ionic constituents are reached within 12 h after transfer to low salinity. one of the central features of ...200314511744
the larval chromatophoral system of the crab, carcinus maenas (l). 196114484566
histamine content of tissues from the crab carcinus maenas. 196114455267
[gonad implants in the crab carcinus maenas pennant]. 195514364897
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