| 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 ... | 2007 | 18229836 |
| 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 ... | 2008 | 18221939 |
| 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 ... | 2006 | 16504184 |
| 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 ... | 2008 | 18214899 |
| 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 ... | 2008 | 18177327 |
| 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 ... | 2008 | 18089130 |
| 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 ... | 2006 | 16086166 |
| range extension of two invasive crab species in eastern australia: carcinus maenas (linnaeus) and pyromaia tuberculata (lockington). | | 2005 | 15823308 |
| 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 ... | 2008 | 17983637 |
| 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 ... | 2008 | 17968591 |
| hemocyanins and the immune response: defense against the dark arts. | the innate immune response is a conserved trait shared by invertebrates and vertebrates. in crustaceans, circulating hemocytes play significant roles in the immune response, including the release of prophenoloxidases. activated phenoloxidase (tyrosinase) participates in encapsulation and melanization of foreign organisms as well as sclerotization of the new exoskeleton after wound-repair or molting. hemocyanin functions as a phenoloxidase under certain conditions and thus also participates in th ... | 2007 | 21672871 |
| 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 ... | 2007 | 17697082 |
| 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 ... | 2011 | 17586505 |
| 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 ... | 2007 | 17540370 |
| 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 ... | 2007 | 17536702 |
| 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 ... | 2004 | 15387189 |
| 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 ... | 2007 | 17465912 |
| 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 ... | 2007 | 17189768 |
| 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 ... | 2007 | 17106720 |
| 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 ... | 2006 | 17056131 |
| 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 ... | 2006 | 17040327 |
| 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 ... | 2006 | 17009759 |
| 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 ... | 2006 | 16942808 |
| 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 ... | 2006 | 16902136 |
| 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 ... | 2006 | 16788899 |
| 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 ... | 2006 | 16788042 |
| 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 ... | 2006 | 16738233 |
| 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 ... | 2006 | 16736501 |
| 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 ... | 2006 | 16651562 |
| 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 ... | 2006 | 16635530 |
| cypermethrin induces glutathione s-transferase activity in the shore crab, carcinus maenas. | cypermethrin is a synthetic pyrethroid that is particularly toxic to crustacea. it is therefore applied as a chemotherapeutant in the salmonid aquaculture industry for the treatment of sea lice infestations. after use, cypermethrin is released directly into the marine environment, to be diluted by fresh seawater. the shore crab, carcinus maenas is found in the vicinity of fish farms, and may come into contact with released cypermethrin. the detoxification enzyme, glutathione s-transferase (gst) ... | 2002 | 12206409 |
| 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 ... | 2006 | 16352450 |
| differential induction of branchial carbonic anhydrase and na(+)/k(+) atpase activity in the euryhaline crab, carcinus maenas, in response to low salinity exposure. | the time course of induction of activity of carbonic anhydrase (ca) and na/k atpase, two enzymes that are central to osmotic and ionic regulation in the eyryhaline green crab, carcinus maenas, was measured in response to a transfer from 32 to 10 ppt salinity. ca activity was low in all gills in crabs acclimated to high salinity. activity was induced in the posterior three gills (g6-g9) starting at 96 hr following transfer to low salinity, with activity peaking at seven post-transfer. na/k atpase ... | 2002 | 12115925 |
| cloning of metallotionein cdnas and its gene in shore crab(carcinus maenas). | metallothioneins are cysteine-rich proteins which chelate metal ion(zn, cu, hg and cd)and regulate ion concentrations in animal body. based on the published amino acid sequence of c.maenas metallothionein, completely degenerated pcr primers were designed and two different types of cdna were amplified from gill tissue rna of c.maenas using rt-pcr method. these cdnas were cloned to pgem t easy vector and the nucleotic acid sequences were determined. the results showed that one group of the cdna se ... | 2000 | 12058179 |
| ion transport across posterior gills of hyperosmoregulating shore crabs (carcinus maenas): amiloride blocks the cuticular na(+) conductance and induces current-noise. | split gill lamellae and gill cuticles of shore crabs (carcinus maenas) adapted to 10 per thousand salinity were mounted in a modified ussing-type chamber. with nacl saline on both sides, split gill lamellae generated a short-circuit current (i(sc)) of -301+/-16 microa cm(-2) at a conductance (g(te)) of 40+/-2 ms cm(-2). the net influxes of na(+) and cl(-) were 8.3+/-2.6 and 18.2+/-2.7 micromol cm(-2) h(-1), respectively. external amiloride (100 micromol l(-1)) reduced g(te) to approximately 50 % ... | 2002 | 11893766 |
| 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 ... | 2005 | 16222811 |
| 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 ... | 2005 | 16150903 |
| 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 ... | 2005 | 15766930 |
| 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 ... | 2005 | 15748747 |
| 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 ... | 2005 | 15748746 |
| protein synthesis and specific dynamic action in crustaceans: effects of temperature. | temperature influences the specific dynamic action (sda), or rise in oxygen uptake rate after feeding, in eurythermal and stenothermal crustaceans by changing the timing and the magnitude of the response. intra-specific studies on the eurythermal crab, carcinus maenas, show that a reduction in acclimation temperature is associated with a decrease in sda magnitude, resulting from an increase in sda duration but a decrease in peak factorial scope (the factorial rise in peak sda over prefeeding val ... | 2001 | 11246047 |
| 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 ... | 2005 | 15748745 |
| 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 ... | 2005 | 15748744 |
| cadmium influx and efflux across perfused gills of the shore crab, carcinus maenas. | cadmium influx across perfused gills of the shore crab carcinus maenas exposed to 9.0 µm cadmium in the external medium ranged from 0.6 to 2.0 nmol cd(2+) g(-1) gill wet wt. per h. cadmium efflux across perfused gills exposed to 9.0 µm cadmium in the internal medium ranged from 0.3 to 0.9 nmol cd(2+) g(-1) gill wet wt. per h. there was no significant difference between cadmium influx and efflux across the gills. cadmium influx across the gills was not detectable after exposure to lanthanum in th ... | 2000 | 10686328 |
| immunolocalization of four antioxidant enzymes in digestive glands of mollusks and crustaceans and fish liver. | the aim of this work was to determine the immunolocalization of the antioxidant enzymes catalase, cu,zn-superoxide dismutase (sod), mn-sod, and glutathione peroxidase (gpx) in the bivalve mollusks mytilus galloprovincialis and crassostrea sp., the crab carcinus maenas, and the teleostean fish mugil cephalus. by immunoblotting, crossreactivity between antibodies and the corresponding proteins in the digestive gland/hepatopancreas of invertebrates and the fish liver was demonstrated. immunohistoch ... | 2000 | 11151409 |
| molecular characterization of v-type h(+)-atpase (b-subunit) in gills of euryhaline crabs and its physiological role in osmoregulatory ion uptake. | the vacuolar-type h(+)-atpase (v-atpase) has been implicated in osmoregulatory ion uptake across external epithelia of a growing variety of species adapted to life in fresh water. in the present study, we investigated whether the v-atpase may also function in a euryhaline species that tolerates brackish water (8 salinity) but not fresh water, the shore crab carcinus maenas. cdna coding for the regulatory b-subunit of the v-atpase was amplified and sequenced from c. maenas gills and partially seq ... | 2001 | 11104708 |
| developing the options for managing marine pests: specificity trials on the parasitic castrator, sacculina carcini, against the european crab, carcinus maenas, and related species. | the impacts of introduced marine pests are becoming increasingly apparent, prompting interest in the possibility of their biological control. we undertook laboratory and field experiments on host selection of one potential control agent (the endoparasitic barnacle, sacculina carcini) against its natural host (the widely invasive european shore crab, carcinus maenas) and several confamilial and more distantly related crustaceans. for comparison, we also tested host specificity in a related parasi ... | 2000 | 11058725 |
| influence of salinity in hemolymph vitellogenin of the shore crab carcinus maenas, to be used as a biomarker of contamination. | | 2004 | 15669731 |
| 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 ... | 2004 | 15464748 |
| 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 ... | 2004 | 15367106 |
| 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 ... | 2004 | 15329340 |
| 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 ... | 2016 | 15178045 |
| 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 ... | 2004 | 15074681 |
| 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 ... | 2002 | 14961261 |
| 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 ... | 2003 | 14672990 |
| 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 ... | 2003 | 14587919 |
| 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 ... | 2003 | 14511744 |
| moult cycle-related changes in biological activity of moult-inhibiting hormone (mih) and crustacean hyperglycaemic hormone (chh) in the crab, carcinus maenas. from target to transcript. | the currently accepted model of moult control in crustaceans relies entirely on the hypothesis that moult-inhibiting hormone (mih) and crustacean hyperglycaemic hormone (chh) repress ecdysteroid synthesis of the target tissue (y-organ) only during intermoult, and that changes in synthesis and/or release of these neurohormones are central to moult control. to further refine this model, we investigated the biological activities of these neuropeptides in the crab carcinus maenas, at the target tiss ... | 2003 | 12869204 |
| a remarkable, precisely timed release of hyperglycemic hormone from endocrine cells in the gut is associated with ecdysis in the crab carcinus maenas. | molting or ecdysis is the most fundamentally important process in arthropod life history, because shedding of the exoskeleton is an absolute prerequisite for growth and metamorphosis. although the hormonal mechanisms driving ecdysis in insects have been studied extensively, nothing is known about these processes in crustaceans. during late premolt and during ecdysis in the crab carcinus maenas, we observed a precise and reproducible surge in hemolymph hyperglycemic hormone (chh) levels, which wa ... | 1999 | 10557280 |
| population size and summer home range of the green crab, carcinus maenas, in salt marsh tidal creeks. | | 1999 | 28281810 |
| comparative esi-ms study of approximately 2.2 mda native hemocyanins from deep-sea and shore crabs: from protein oligomeric state to biotope. | in the past years, the potential of electrospray ionization mass spectrometry (esi-ms) for the observation of intact weak interactions, such as non-covalent protein-ligand, protein-protein, protein-dna complexes, has spread out. the coupling of esi with time-of-flight (tof) and quadrupole-time-of-flight (q-tof) analyzers has even enabled the detection of larger complexes with molecular weights greatly higher than 200 kda. in this paper, we report a comparative esi-ms study on the protein quatern ... | 2003 | 12745211 |
| influence of oxygen partial pressures on protein synthesis in feeding crabs. | many water-breathing animals have a strategy that consists of maintaining low blood po2 values in a large range of water oxygenation level (4-40 kpa). this study examines the postprandial changes in o2 consumption, arterial blood po2, and tissue protein synthesis in the shore crab carcinus maenas in normoxic, o2-depleted, and o2-enriched waters to study the effects of this strategy on the o2 consumption and peptide bond formation after feeding. in normoxic water (21 kpa), the arterial po2 was 1. ... | 2003 | 12529287 |
| a non-destructive assessment of the exposure of crabs to pah using elisa analyses of their urine and haemolymph. | urine and haemolymph can be repeatedly sampled from crabs with no (or limited) damage to the organism. their analysis offers a measure of the animals' exposure to biologically available contaminants. shore crabs (carcinus maenas) were exposed to the pahs phenanthrene and pyrene at concentrations ranging from 20 to 200 microg l(-1). after 48 h, urine and haemolymph samples were taken and analysed using elisa and uv-fluorescence spectrophotometry. high correlations were recorded between the two se ... | 2012 | 12408657 |
| specific dynamic action in the shore crab, carcinus maenas (l.), in relation to acclimation temperature and to the onset of the emersion response. | the rate of oxygen uptake (mo(2)) of shore crabs following a period of fasting varied directly with acclimation temperature, with a q(10) of 2.96 between 7 degrees and 15 degrees c and a q(10) of 2.11 between 15 degrees and 22 degrees c. the factorial rise in mo(2) following a meal (specific dynamic action [sda]) ranged between 1.9 and 3.1 and varied with temperature, being highest at 15 degrees c and significantly lower at both 7 degrees and 22 degrees c, despite similar ration sizes in all gro ... | 2013 | 12324891 |
| active ammonia excretion across the gills of the green shore crab carcinus maenas: participation of na(+)/k(+)-atpase, v-type h(+)-atpase and functional microtubules. | although aquatic animals are generally believed to export nitrogenous waste by diffusion of nh(3) or nh(4)(+) across external epithelia, evidence for active ammonia excretion has been found in a number of species. in the euryhaline green shore crab carcinus maenas, active excretion of ammonia across isolated gills is reduced by inhibitors of the na(+)/k(+)-atpase and vacuolar-type h(+)-atpase. in addition, a functional dynamic microtubule network is necessary, since application of colchicine, ta ... | 2002 | 12177142 |
| glycoproteins from the cuticle of the atlantic shore crab carcinus maenas: i. electrophoresis and western-blot analysis by use of lectins. | the protein and glycoprotein content of four different neutral or acidic solvent extracts (0.5 m kcl, 10% edta, 0.1 n hcl, or 2% acetic acid) from the mineralized exoskeleton of a decapod crustacean, the atlantic shore crab carcinus maenas, were characterized by quantitative analysis of proteins, sds-page analysis, and probing with lectins on blots. the lectins used were conconavalin a, jacalin, soybean agglutinin, maackia amurensis agglutinin ii, and sambucus nigra agglutinin. the results show ... | 2002 | 11842016 |
| neurogenesis in the central olfactory pathway of the adult shore crab carcinus maenas is controlled by sensory afferents. | the number of olfactory projection neurons (opns) in the brain of the juvenile and adult shore crab carcinus maenas continues to increase during the life of the animal. in vivo labeling of adult crabs with the proliferation marker bromodeoxyuridine (brdu) revealed a group of proliferating neuronal precursor cells in the lateral soma clusters (lcs) and in the soma clusters of the hemiellipsoid bodies (hbcs). the lcs contain the cell bodies of the olfactory projection neurons and the hbcs house th ... | 2001 | 11745646 |
| the influence of oxygen stress on female choice for male nest structure in the common goby. | this study examines the role of dissolved oxygen in modifying female mate choice in the common goby, pomatoschistus microps. experimental manipulations of nests showed that under normal (saturated) oxygen conditions, females preferred to spawn in nests with the most elaborate construction, that is, those with the most sand on top and the smallest entrance. such manipulated nests proved less vulnerable to detection by an egg predator, the shore crab, carcinus maenas, but these small entrances may ... | 1999 | 10053086 |
| characterization of cdna encoding molt-inhibiting hormone of the crab, cancer pagurus; expression of mih in non-x-organ tissues. | synthesis of ecdysteroids (molting hormones) by crustacean y-organs is regulated by a neuropeptide, molt-inhibiting hormone (mih), produced in eyestalk neural ganglia. we report here the molecular cloning of a cdna encoding mih of the edible crab, cancer pagurus. full-length mih cdna was obtained by using reverse transcription-polymerase chain reaction (rt-pcr) with degenerate oligonucleotides based upon the amino acid sequence of mih, in conjunction with 5'- and 3'-race. full-length clones of m ... | 2001 | 11707332 |
| neurogenesis in the central olfactory pathway of adult decapod crustaceans. | based on the previous findings that the number of olfactory projection neurons increases continuously in adult shore crabs, carcinus maenas, and that this increase is associated with the presence of 5-bromo-2-deoxyuridine (brdu)-positive, proliferating cells in the appropriate soma clusters (lateral soma clusters), we studied the further fate of these proliferating cells and the presence of apparent adult neurogenesis throughout the central olfactory pathway of diverse species of decapod crustac ... | 1998 | 10049222 |
| rubidium uptake is increased in shore crabs, carcinus maenas, acclimated to dilute seawater. | in dilute seawater, carcinus maenas hyperosmoregulates by actively absorbing na, k, and cl. here we characterize k uptake using a novel technique. rb was used as a tracer for k transport, and hemolymph rb levels were measured using cation chromatography. hemolymph rb was detectable at 0.1 mmol l(-1), which enabled determination of initial rate of rb uptake. crabs maintained for 3 wk in dilute artificial seawater (35% asw crabs) maintained na and k above the level of the external media and had el ... | 2013 | 11517457 |
| crustacean hyperglycaemic hormone (chh)-like peptides and chh-precursor-related peptides from pericardial organ neurosecretory cells in the shore crab, carcinus maenas, are putatively spliced and modified products of multiple genes. | about 24 intrinsic neurosecretory neurons within the pericardial organs (pos) of the crab carcinus maenas produce a novel crustacean hyperglycaemic hormone (chh)-like peptide (po-chh) and two chh-precursor-related peptides (po-cprp i and ii) as identified immunochemically and by peptide chemistry. edman sequencing and ms revealed po-chh as a 73 amino acid peptide (8630 da) with a free c-terminus. po-chh and sinus gland chh (sg-chh) share an identical n-terminal sequence, positions 1-40, but the ... | 2001 | 11336648 |
| the competitive and predatory impacts of the nonindigenous crab carcinus maenas (l.) on early benthic phase dungeness crab cancer magister dana. | we evaluate the potential competitive and predatory impacts of nonindigenous european green crab carcinus maenas on native dungeness crab cancer magister in the northeast pacific. the coastal estuaries of washington state, usa, provide appropriate habitat for recently introduced green crab, yet these areas are important nursery grounds for dungeness crab and contribute greatly to the coastal crab fishery. juvenile dungeness crabs are dependent on limited intertidal epibenthic shell for refuge ha ... | 2001 | 11239624 |
| hemolymph levels of methyl farnesoate increase in response to osmotic stress in the green crab, carcinus maenas. | the salinity of estuarine environments can vary widely, exposing resident organisms to considerable osmotic stress. the green crab carcinus maenas is well known for its ability to osmoregulate in response to such stress. therefore, we tested the relationship between osmoregulation and hemolymph levels of methyl farnesoate (mf), a compound previously shown to rise in response to various types of environmental stresses. when crabs were transferred from 100% seawater to dilute (hypo-osmotic) seawat ... | 2001 | 11223391 |
| involvement of crustacean hyperglycemic hormone in the control of gill ion transport in the crab pachygrapsus marmoratus. | total extracts of sinus glands (sg) of the euryhaline grapsid crab pachygrapsus marmoratus contain peptidic factor(s) that stimulate osmoregulatory processes in isolated and perfused posterior gills from crabs acclimated to dilute seawater. this study investigated the nature of the active factor(s). separation of p. marmoratus sg peptides by reverse-phase hplc, followed by a direct enzyme-linked immunosorbent assay using an anti-carcinus maenas crustacean hyperglycemic hormone (chh) antiserum, i ... | 2000 | 11017781 |
| observations on the interaction of zinc and cadmium uptake rates in crustaceans (amphipods and crabs) from coastal sites in uk and france differentially enriched with trace metals. | this paper presents results on the possible interaction of zinc and cadmium uptake rates in crustaceans. zn and cd uptake rates were measured in amphipods (orchestia gammarellus) and crabs (carcinus maenas and pachygrapsus marmoratus) from five coastal sites in britain and france subjected to different degrees of trace metal enrichment. the presence or absence of 100 µg l(-1) of one metal (1.53 µm l(-1) zn, 0.89 µm l(-1) cd) had an inconsistent effect on the rate of uptake of the other metal by ... | 2000 | 10958954 |
| phenotypic clines, plasticity, and morphological trade-offs in an intertidal snail. | understanding the genetic and environmental bases of phenotypic variation and how they covary on local and broad geographic scales is an important goal of evolutionary ecology. such information can shed light on how organisms adapt to different and changing environments and how life-history trade-offs arise. surveys of phenotypic variation in 25 littorina obtusata populations across an approximately 400-km latitudinal gradient in the gulf of maine revealed pronounced clines. the shells of snails ... | 2000 | 10937192 |
| estimating the energetic cost of fighting in shore crabs by noninvasive monitoring of heartbeat rate. | after establishing shore crabs, carcinus maenas, individually in separate aquaria, we used a noninvasive infrared phototransducer to monitor their heartbeat rate continously before, during and after fights with intruder crabs. we confirmed that heartbeat rate is a reliable indicator of oxygen consumption and then used it to estimate indirectly the energetic cost of fights differing in duration and intensity, and its dependence on prior residence and relative size of opponent. prior residence in ... | 2000 | 10792926 |
| identification of orcokinin gene-related peptides in the brain of the crayfish procambarus clarkii by the combination of maldi-tof and on-line capillary hplc/q-tof mass spectrometries and molecular cloning. | we developed a strategy for the exploration of brain peptides in the red swamp crayfish, procambarus clarkii, utilizing the combined techniques of matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry (maldi-tof ms), molecular cloning, and on-line capillary reversed-phase hplc/quadrupole orthogonal acceleration time-of-flight (q-tof)-ms. we initially performed direct maldi-tof ms analysis with slices of the brain. the ms spectra from a slice of the olfactory lobe indi ... | 2000 | 10753578 |
| haemolymph mg(2+) regulation in decapod crustaceans: physiological correlates and ecological consequences in polar areas. | reptant decapod crustaceans are almost absent from the southern ocean south of the antarctic convergence. we tested the hypothesis that this may be due to the reduced ability of this group to regulate mg(2+) levels in the haemolymph ([mg(2+)](hl)). mg(2+) acts as an anaesthetic in marine invertebrates and its level is higher in reptantia (crabs such as cancer spp., chionoecetes spp., maja spp., 30-50 mmol l(-)(1)) than in natantia (prawns such as pandalus spp., palaemon spp., crangon spp., 5-12 ... | 2000 | 10729286 |
| the ability to feed in hypoxia follows a seasonally dependent pattern in shore crab carcinus maenas. | the ability of the adult shore crab carcinus maenas, native to the bay of arcachon (sw france), to feed in hypoxia was determined at various seasons. crabs previously kept at field temperature were fed after a 5-day fasting period at 15 degrees c. their blood oxygenation and ph regulation strategy and also their gill anatomy were analysed. from may to october, c. maenas feed at levels of o(2) partial pressure (p(o(2))) in the water, pwo(2)=2 kpa (1 mg l(-1)), without switching to their anaerobic ... | 2000 | 10727691 |
| changes in metallothionein concentrations in response to variation in natural factors (salinity, sex, weight) and metal contamination in crabs from a metal-rich estuary. | intermoult male and female crabs pachygrapsus marmoratus and carcinus maenas were sampled from three sites between the mouth and 25 km upstream in the gironde, the most cd-contaminated estuary in france, in order to study the relative importance of natural factors (salinity, sex, weight) and accumulated metal concentrations on metallothionein (mt) concentrations. in the two species studied, higher metal, total protein and mt concentrations were observed in the hepatopancreas than in the gills. i ... | 2000 | 10713280 |
| agonistic behaviour and biogenic amines in shore crabs carcinus maenas. | to investigate the role of certain neurohormones in agonistic behaviour, fights were staged between pairs of size-matched male shore crabs carcinus maenas, and blood samples were taken immediately after the contests had been resolved. samples were also taken from these crabs at rest (before and after fighting) and after walking on a treadmill. a control group of crabs also had samples taken on each experimental day. concentrations of tyramine, dopamine, octopamine, serotonin (5-ht) and norepinep ... | 2000 | 10637182 |
| ecdysis of decapod crustaceans is associated with a dramatic release of crustacean cardioactive peptide into the haemolymph. | on the basis of detailed analyses of morphological characteristics and behavioural events associated with ecdysis in a crab (carcinus maenas) and a crayfish (orconectes limosus), a comprehensive substaging system has been introduced for the ecdysis stage of the moult cycle of these decapod crustaceans. in a remarkably similar stereotyped ecdysis sequence in both species, a passive phase of water uptake starting with bulging and rupture of thoracoabdominal exoskeletal junctions is followed by an ... | 2000 | 10637181 |
| asymmetry and fighting performance in the shore crab carcinus maenas. | fluctuating asymmetries (left-right differences in symmetric traits) can be negatively related to fitness parameters in a number of biological systems. hence, it has been suggested that symmetric individuals should outcompete asymmetric individuals during intraspecific agonistic encounters. however, there is a lack of experimental evidence for such a relationship. we investigated the relationship between trait asymmetry (both directional and fluctuating asymmetry) and the outcome of agonistic en ... | 1999 | 10458894 |
| female sex pheromone-mediated effects on behavior and consequences of male competition in the shore crab (carcinus maenas). | exposure to receptive female pheromone elicits guarding behavior in shore crab males (carcinus maenas), but little is known about the effects of sex pheromone on male competition or if the female plays an active role in mate choice. this study examined whether female pheromone enhanced agonistic behavior between males and what effects visual and chemical cues had on the rules and costs of such contests. we also investigated whether females exhibit a preference for males in terms of size. under l ... | 2003 | 12647853 |
| work-dependent deactivation of a crustacean muscle. | active shortening of respiratory muscle l2b from the crab carcinus maenas results in contractile deactivation, seen as (1) a decline of force during the course of isovelocity shortening, (2) a reduction in the rate of force redevelopment following shortening, (3) a depression of the level of isometric force reached following shortening, and (4) an accelerated relaxation at the end of stimulation. the degree of deactivation increases with increasing distance of shortening, decreases with increasi ... | 1999 | 10460743 |
| increases in tissue free amino acid levels in response to prolonged emersion in marine crabs: an ammonia-detoxifying process efficient in the intertidal carcinus maenas but not in the subtidal necora puber. | carcinus maenas and necora puber were exposed to air for 72 h and 18 h, respectively, at 18 °c. changes in the free amino acid (faa) content of their muscle, hepatopancreas and haemolymph were recorded during air-exposure and subsequent reimmersion. muscle and hepatopancreas urate contents and haemolymph serum protein levels were also measured during emersion. in air-exposed c. maenas, the muscle faa pool increased significantly within the first 24 h of emersion. this increase was due to an incr ... | 1999 | 10409490 |
| endocrine regulation of the phosphatidylinositol pathway in the norway lobster, nephrops norvegicus, and the shore crab, carcinus maenas. | the present study examines the mode of action of eyestalk factors, in particular crustacean hyperglycaemic hormone (chh), on known target tissues (muscle and hepatopancreas) in two decapod crustacean species, nephrops norvegicus and carcinus maenas. the possibility that receptors to chh are coupled to an elevation of cytosolic ca2+ derived from intracellular stores via activation of the phosphatidylinositol pathway was investigated. using an inositol 1,4,5-trisphosphate (insp3)-specific competit ... | 1996 | 8921359 |
| in situ and in vitro identification and characterization of cardiac ganglion neurons in the crab, carcinus maenas. | the aim of this study was to investigate the intrinsic membrane properties and hormonal responses of individual central pattern generating neurons in the cardiac ganglion of the shore crab carcinus maenas. because the cardiac ganglion in this crustacean species is buried within the heart musculature and is therefore inaccessible for direct morphological and electrophysiological analysis, we developed two novel in vitro preparations. first, to make the ganglion accessible, we established a brief ... | 1999 | 10368413 |
| heterothermal acclimation: an experimental paradigm for studying the control of thermal acclimation in crabs. | a method for the study of the control of the attainment of thermal acclimation has been applied to the crabs, cancer pagurus and carcinus maenas. crabs were heterothermally acclimated by using an anterior-posterior partition between two compartments, one at 8 degrees c and the other at 22 degrees c. one compartment held a three-quarter section of the crab including the central nervous system (cns), eye stalks, and ipsilateral legs; the other held a quarter section including the contralateral leg ... | 1999 | 10339617 |
| subunit composition and n-terminal analysis of arthropod hemocyanins. | fourteen structural subunits of hemocyanins from two different infraorders of crustacea, brachyura (maia squinado, carcinus maenas) and astacidea (homarus americanus) were isolated and characterized. n-terminal amino acid sequences were determined and compared with known sequences of crustacean and cheliceratan hemocyanins. relationships between the investigated polypeptide chains were established. the results demonstrate that the degree of identity, calculated from the amino terminal sequences, ... | 1999 | 10327595 |
| metabolic consequences of agonistic behaviour: crab fights in declining oxygen tensions. | the energetic consequences of fighting, which may depend on environmental conditions, can be an important factor shaping contest strategy and duration. energy expenditure may be costly to fitness because it depletes reserves that could otherwise have been allocated to reproduction, and metabolites are produced that may constrain subsequent activities. we examined the variation in the metabolic consequences of fighting in relation to hypoxia. contests were staged between pairs of size-matched mal ... | 1999 | 10049475 |
| na+-k+-atpase and na+/ca2+ exchange activities in gills of hyperregulating carcinus maenas. | na+-k+-atpase and na+/ca2+ exchange activities were studied in gills of carcinus maenas in seawater (sw) and after transfer to dilute seawater (dsw). carcinus hyperregulates its hemolymph osmolarity through active uptake of na+, cl-, and ca2+. in dsw total na+-k+-atpase activity in posterior gills quadrupled; na+/ca2+ exchange specific activity was unaffected, and total activity increased 1.67-fold. short-circuit current (isc) in voltage-clamped posterior gill hemilamellae was -181 microa/cm2 in ... | 1999 | 9950929 |
| a comparative immunocytochemical study of the hyperglycaemic, moult-inhibiting and vitellogenesis-inhibiting neurohormone family in three species of decapod crustacea. | eyestalks of the palinuran species jasus lalandii and panulirus homarus, and the brachyuran species carcinus maenas, were examined with antisera raised against purified crustacean hyperglycaemic hormone (chh) of the astacidean species homarus americanus and procambarus bouvieri, as well as the brachyuran species cancer pagurus. other antisera used in this investigation were raised against purified moult-inhibiting hormone (mih) of c. pagurus and vitellogenesis-inhibiting hormone (vih) of h. amer ... | 1999 | 9931363 |
| the force-velocity properties of a crustacean muscle during lengthening | muscle force during active lengthening was characterized for scaphognathite levator muscle l2b from the crab carcinus maenas. the muscle was tetanically stimulated and, during the peak of the contraction, stretched at constant velocity. the total strain was approximately 4 %, the strain rates ranged from 0.03 to 1.6 muscle lengths s-1 (l s-1), and the temperature was 15 degreesc. force increased throughout stretch. during low-velocity stretch, up to approximately 0.3 l s-1, force rose during iso ... | 1999 | 9929461 |
| induction of a putative monooxygenase of crabs (carcinus spp.) by polycyclic aromatic hydrocarbons. | as part of a programme to develop biomarker assays for polycyclic aromatic hydrocarbons (pahs) in marine invertebrates, two species of crabs, carcinus maenas and carcinus aestuarii were exposed to benzo(a)pyrene (b(a)p) or crude oil. microsomes were prepared from the midgut gland (hepatopancreas), examined by gel electrophoresis and western blotting and assayed for b(a)p monooxygenase activity. in early experiments there was evidence of protein degradation and results were inconsistent and incon ... | 1999 | 23885863 |
| induction and identification of cadmium-, zinc- and copper-metallothioneins in the shore crab carcinus maenas (l.). | shore crabs carcinus maenas were injected with either cd, cu or zn to determine whether different metals could induce specific metallothionein (mt) isoforms in the midgut gland. furthermore, the relative ability of the three metals to induce mt was quantified. accumulation of the three metals in the midgut gland caused variable and in the case of cd and zn significant increases in mt levels. the increase in mt levels (pmol g-1 midgut gland) per nmol of metal accumulated was determined as 90, 60 ... | 1998 | 9827039 |
| nitrogen metabolism of two portunid crabs, carcinus maenas and necora puber, during prolonged air exposure and subsequent recovery: a comparative study | carcinus maenas and necora puber were exposed to air for 72 h and 18 h, respectively, at 18 degreesc. nitrogen excretion, blood and muscle ammonia content and blood urate and lactate content were recorded throughout the experimental emersion and following reimmersion (recovery period). during emersion, the rate of ammonia excretion was strongly reduced in both species, while urea and amine excretion were not enhanced. blood and muscle ammonia content increased steadily, reaching 1.3 and 10.4 mmo ... | 1998 | 9698586 |
| haemocyanin and the binding of cadmium and zinc in the haemolymph of the shore crab carcinus maenas (l.). | the trace metals cadmium and zinc are taken up from solution into haemolymph of the shore crab, carcinus maenas, where they bind to the respiratory pigment haemocyanin. investigations using fplc and page to separate the constituent dodecamer and hexamer aggregations of haemocyanin showed a difference between the distribution of cadmium and zinc between the two aggregate states. in the haemolymph, labelled cadmium binds not only to haemocyanin but, at least initially, it is also associated with l ... | 1998 | 9646522 |