Publications

[proprioceptive regulation of locomotor appendix elevation during lateral walking in the crab carcinus maenas (l.)].		2003	5561524
light- and electron-microscopic observations on the metacercaria of a spelotrema sp. (trematoda. microphallidae) encysted in carcinus maenas.		2003	5690291
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
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
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
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
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
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
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
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
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
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
[accumulation of fe, cu, zn, mg, mn and co in the ovary of carcinus maenas l. during ovogenesis].	during ovogenesis the ovary of carcinus maenas shows a continuous accumulation of fe, cu, mg, mn and co. for zn the accumulation seems to stop for gonad indexes near 6.5. the goal of this accumulation is not determined. nevertheless we suppose that it is in relation with the role of organic reserves that possess the female sexual cells in decapods and with the synthesis of enzymes and hemocyanin.	2002	134766
[cytochemical observations of hemocytes in decapod brachyuran crustacea (author's transl)].	hemocytes from two species of crabs, eriocheir sinensis and carcinus maenas, have been submitted to different cytochemical reactions in order to bring out the nature of granules' content, either by specific coloration or be enzymatic digestion. light as well as electron microscopy has been used. the granules appeared to be made essentially of basic proteins, rich in arginin and disulfide bridges but poor in tyrosin. these proteins are linked with nonglycogenic carbohydrates. glycogen deposits of ...	2002	127769
expression of crustacean (callinectes sapidus) molt-inhibiting hormone in insect cells using recombinant baculovirus.	molt-inhibiting hormone (mih) negatively regulates the synthesis of ecdysteroid molting hormones by crustacean y-organs. we report here the expression of blue crab (callinectes sapidus) mih in insect cells using recombinant baculovirus. insect sf9 cells were transfected with recombinant baculovirus containing a dna insert encoding the c. sapidus mih prohormone (signal sequence plus mature hormone). the construct was designed to yield a mature, fully processed recombinant mih (recmih). several ba ...	2002	11754021
antioxidant enzymes and peroxisome proliferation in relation to contaminant body burdens of pahs and pcbs in bivalve molluscs, crabs and fish from the urdaibai and plentzia estuaries (bay of biscay).	with the aim of studying levels of antioxidant and peroxisomal enzymes and the structure of peroxisomes in relation to body burdens of polycyclic aromatic hydrocarbons (pahs) and polychlorinated biphenyls (pcbs), mussels mytilus galloprovincialis, oysters crassostrea sp., crabs carcinus maenas and mullets mugil cephalus were sampled in two basque estuaries (bay of biscay): urdaibai (laida, txatxarramendi, arteaga, and downstream a sewage treatment plant-stp) and plentzia. in general, animals sho ...	2002	12062156
first confirmation of human diarrhoeic poisonings by okadaic acid esters after ingestion of razor clams (solen marginatus) and green crabs (carcinus maenas) in aveiro lagoon, portugal and detection of okadaic acid esters in phytoplankton.	a new outbreak of human diarrhoeic poisonings (dsp) with esters of okadaic acid (oa) was confirmed after ingestion of razor clams (solen marginatus) harvested at aveiro lagoon (nw portugal) in the summer of 2001. accumulation of marine toxins in second order consumers was investigated in the edible parts of a shellfish predator abundant at aveiro lagoon, the green crab carcinus maenas. okadaic acid was found, also in a predominant esterified form. levels in edible parts (comprising mainly viscer ...	2002	12076653
inhibition of carbonic anhydrase in the gills of two euryhaline crabs, callinectes sapidus and carcinus maenas, by heavy metals.	two subcellular fractions of gill tissue, cytoplasm and basolateral membranes, from two species of euryhaline decapod crustaceans, callinectes sapidus and carcinus maenas, acclimated to low salinity, were isolated via differential centrifugation. carbonic anhydrase activity from both fractions was titrated against a variety of heavy metals in vitro. the metals ag(+), cd(2+), cu(2+) and zn(+) showed inhibitory action against the enzyme. ki values for these metals against cytoplasmic ca from c. sa ...	2002	12458188
identification and ultrastructural characterization of a novel virus from fish.	during routine investigations on fish, a virus (isolate df 24/00) with novel morphological features and hitherto undescribed morphogenesis was isolated from a white bream (blicca bjoerkna l.; teleostei, order cypriniformes). cell-free virions consist of a rod-shaped nucleocapsid (120-150x19-22 nm) similar to that seen in baculoviruses. the virion has a bacilliform shape (170-200x75-88 nm) reminiscent of rhabdoviruses with an envelope containing coronavirus-like spikes (20-25 nm). df 24/00 replic ...	2001	11714959
isolation and characterisation of five neurotoxic and cardiotoxic polypeptides from the sea anemone anthopleura elegantissima.	five toxins (ape 1 to ape 5) of the sea anemone species anthopleura elegantissima (brandt) have been isolated from a toxic by-product fraction of its concentrated crude watery-methanolic extract, prepared previously for the isolation of a neuropeptide (the head-activator) by schaller and bodenmüller (proc. natl. acad. sci. usa 78 (1981) 7000) from 200kg sea anemones. toxin purification was performed by desalting of the starting material by dialysis (mwco 3500) against distilled water, anion exch ...	2001	11072049
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 ...	2001	18088946
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
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
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
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
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
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
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
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
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
[microphallidae travassos, 1920. trematoda. xx. megalophallus carcini n. sp., experimental adult from a metacercaria of carcinus maenas pennant].		2000	5474516
epizootiology of the parasitic dinoflagellate hematodinium sp. in the american blue crab callinectes sapidus.	hematodinium sp. is a parasitic dinoflagellate that infects and kills blue crabs callinectes sapidus. periodic outbreaks of dinoflagellate infections with subsequent high host mortalities prompted a study of the epizootiology and distribution of the crab pathogen. hemolymph samples from over 13000 crabs were assessed for infections over 8 yr. moderate to high prevalences were found at several locations along the atlantic and gulf coasts of the united states. in the coastal bays of maryland and v ...	2000	11145454
endocrine cells in the gut of the shore crab carcinus maenas immunoreactive to crustacean hyperglycaemic hormone and its precursor-related peptide.	the distribution and morphology of gut endocrine cells, which are immunoreactive to crustacean hyperglycaemic hormone (chh) and the corresponding precursor-related peptide (cprp), have been described in the shore crab carcinus maenas. the cells are uniquely distributed throughout the fore- and hindgut, but were never observed in the midgut or associated caeca. expression of chh and cprp in the gut endocrine cells is generally restricted to premoult, although small numbers of immunoreactive cells ...	2000	10805088
expression of arginine kinase enzymatic activity and mrna in gills of the euryhaline crabs carcinus maenas and callinectes sapidus.	phosphagen kinases catalyze the reversible dephosphorylation of guanidino phosphagens such as phosphocreatine and phosphoarginine, contributing to the restoration of adenosine triphosphate concentrations in cells experiencing high and variable demands on their reserves of high-energy phosphates. the major invertebrate phosphagen kinase, arginine kinase, is expressed in the gills of two species of euryhaline crabs, the blue crab callinectes sapidus and the shore crab carcinus maenas, in which ene ...	2000	10903154
immunochemical localisation of proliferating cells in mussel digestive gland tissue.	the distribution of proliferating cells in the digestive gland of the common marine mussel, mytilus galloprovincialis lmk, was investigated by means of immunochemical techniques employing pc10, a commercial monoclonal antibody to the proliferating cell nuclear antigen (pcna). immunoblot analysis of digestive gland whole homogenates revealed a single crossreactive band of 36-37 kda, identical to the corresponding protein of rat liver and murine melanoma cells. a band of slightly higher electropho ...	1999	10661321
entrainment of bimodal circatidal rhythms in the shore crab carcinus maenas.	individuals of the shore crab carcinus maenas were exposed to artificial cycles, applied in tidal antiphase, of pairs of the three major environmental variables that entrain circatidal rhythmicity in this species: salinity, temperature, and hydrostatic pressure. during entrainment, the observed locomotor activity patterns were dominated by exogenous responses to high pressure, low temperature, or low salinity. in subsequent constant conditions, many of the crabs showed bimodal circatidal rhythms ...	1999	2133140
na+, k+ and amino-compounds changes during volume regulation in carcinus maenas isolated axons [proceedings].		1999	84584
behavioral physiology of four crab species in low salinity.	reports focusing on the behavioral responses of crabs to exposure to low salinity have involved choice chamber experiments or quantification of changes in activity. in addition to describing changes in locomotor activity in four species of crabs of differing osmoregulatory ability, the present study describes six behaviors: increased movement of the mouthparts, cleaning of the mouthparts with the chelae, cleaning of the antennae and antennules with the maxillipeds, flicking of the antennae, retr ...	1999	28296479
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
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
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
purification and characterization of a cysteine-rich 11.5-kda antibacterial protein from the granular haemocytes of the shore crab, carcinus maenas.	extracts of the granular haemocytes of carcinus maenas were subjected to ion-exchange chromatography and reverse-phase (rp)-hplc to investigate the presence of an antibacterial protein of approximately 11 kda. this protein was isolated, characterized and subjected to partial amino acid sequence analysis. it was found by mass spectrometry to have a molecular mass of 11 534 da, to be cationic and hydrophobic and active only against marine gram-positive bacteria. in addition its activity is stable ...	1999	10491079
structure, distribution, and biological activity of novel members of the allatostatin family in the crayfish orconectes limosus.	in the central and peripheral nervous system of the crayfish, orconectes limosus, neuropeptides immunoreactive to an antiserum against allatostatin i (= dipstatin 7) of the cockroach diploptera punctata have been detected by immunocytochemistry and a sensitive enzyme immunoassay. abundant immunoreactivity occurs throughout the central nervous system in distinct interneurons and neurosecretory cells. the latter have terminals in well-known neurohemal organs, such as the sinus gland, the pericardi ...	1999	10477125
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
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
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
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
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
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
pcr cloning and expression of the molt-inhibiting hormone gene for the crab (charybdis feriatus).	a pcr-based genomic dna walking technique was used to clone the gene for the molt-inhibiting hormone of the crab, charybdis feriatus. several overlapping genomic clones were isolated, and the mih gene for the crab was reconstructed. dna sequence determination of the overlapping clone reveals that the mih gene spans 4.3kb and consists of three exons and two introns. exons 1 and 2 carry a coding sequence for the signal peptide, and exons 2 and 3 consist of coding sequence for the mature peptide. t ...	1998	9931416
fine structural survey of old cuticle degradation during pre-ecdysis in two european atlantic crabs.	light and transmission electron microscopy were used to monitor changes due to the degradation of the old exoskeleton and related events in the sclerites, articular membranes, and gills of two decapod crustaceans (carcinus maenas and macropipus puber) during pre-ecdysis. in both sclerites and articular membranes, degradation follows a similar general pattern in both crab species, while the gill cuticle appears unaltered. in early pre-ecdysis (d(0)), the degradation of the old cuticle starts with ...	1998	18627837
sodium/proton antiporter in the euryhaline crab carcinus maenas: molecular cloning, expression and tissue distribution.	gill epithelial cells of euryhaline crustaceans demonstrate net inward transport of sodium ions, possibly via apical na+/h+ antiporters, na+/k+/2cl- cotransporters or na+ channels working in series with the basolateral na(+) + k(+)-atpase. we have identified and sequenced the cdna coding for a crustacean na+/h+ antiporter, starting with mrna isolated from gills of the euryhaline green shore crab carcinus maenas. the complete 2595-base-pair cdna includes an open reading frame coding for a 673-ami ...	1997	9104780
distribution of centrifugal neurons targeting the soma clusters of the olfactory midbrain among decapod crustaceans.	to determine the distribution of two systems of centrifugal neurons innervating the soma clusters of the olfactory midbrain across decapod crustaceans, brains of the following nine species comprising most infraorders were immunostained with antibodies against dopamine and the neuropeptides substance p and fmrfamide: macrobrachium rosenbergii, homarus americanus, cherax destructor, orconectes limosus, procambarus clarkii, astacus leptodactylus, carcinus maenas, eriocheir sinensis and pagurus bern ...	1997	9106436
isolation and identification of multiple neuropeptides of the allatostatin superfamily in the shore crab carcinus maenas.	20 neuropeptides belonging to the allatostatin superfamily were isolated from extracts of cerebral and thoracic ganglia of the shore crab carcinus maenas. they were purified by hplc, monitored by radioimmunoassay and identified by mass spectrometry and amino acid sequencing. the allatostatins are characterised by a common c-terminal pentapeptide sequence -yxfgl-nh2. previously such peptides have only been reported from insects. in insects the variable post-tyrosyl residue is restricted to ala, a ...	1997	9461295
"exolysosomes," enzyme-containing vesicles in the ecdysial space of molting crabs.	free vesicle-like bodies (vlbs) present in the ecdysial space of cuticle regions undergoing degradation during preecdysis of the atlantic shore crab carcinus maenas have been interpreted either as infectious organisms or as secretion structures associated with degradation of the old cuticle. ultrastructural, cytochemical, and immunocytological investigations were performed to test these hypotheses and to see whether vlbs are peculiar to this crab species. similar vlbs were systematically found i ...	1997	9245765
continuous neurogenesis in the olfactory brain of adult shore crabs, carcinus maenas.	to scrutinize the common belief that the number of neurons in the cns of adult decapod crustaceans stays constant, in spite of their dramatic postlarval increase in size, i counted olfactory projection neurons (opns) in the brains of differently-sized postlarval shore crabs, carcinus maenas, and performed in vivo labeling of proliferating cells with 5-bromo-2'-deoxyuridine (brdu) on brains of adults. the number of opns increases continuously throughout the postlarval life of shore crabs and appr ...	1997	9262167
involvement of a 3beta-hydroxysteroid dehydrogenase activity in ecdysteroid biosynthesis.	ecdysteroid biosynthesis was analyzed in vitro using dissociated y-organ cells from the shore crab carcinus maenas. 3-dehydroecdysone (3de) was detected as a minor secretory product, in addition to the formerly identified end-products 25-deoxyecdysone and ecdysone (e). in conversion studies, 3de was formed from tritiated 5beta-ketodiol (2,22,25-trideoxyecdysone), 2,22-deoxyecdysone and 2-deoxyecdysone but not from e. further experiments were performed in order to understand the interconversions ...	1997	9140085
crustacean hyperglycaemic hormone in the nervous system of the primitive crustacean species daphnia magna and artemia salina (crustacea: branchiopoda).	crustacean hyperglycaemic hormone-immunoreactive neuronal systems are detected in the central and peripheral nervous systems of two entomostracan crustaceans, daphnia magna and artemia salina, by immunocytochemistry using specific antisera against crustacean hyperglycaemic hormones of the decapod crustaceans orconectes limosus and carcinus maenas. in d. magna, four small putative interneurones are detected in the brain. in the thorax, ten bipolar peripheral neurones are stained by both antisera. ...	1997	9023085
distribution of presumptive chemosensory afferents with fmrfamide- or substance p-like immunoreactivity in decapod crustaceans.	in five species of decapod crustaceans--cherax destructor (crayfish), carcinus maenas (crab), homarus americanus (clawed lobster), eriocheir sinensis (crab), macrobrachium rosenbergii (shrimp)--immunocytochemical stainings revealed the presence of sensory afferents with fmrfamide-like immunoreactivity in the central nervous system. these afferents were extremely thin, very numerous, and innervated all sensory neuropils except the optic and olfactory lobes. in their target neuropils they gave ris ...	1997	9037486
the anaerobic endproduct lactate has a behavioural and metabolic signalling function in the shore crab	this study presents the first evidence that, in invertebrates, the anaerobic endproduct lactate has an alarm signal function and induces metabolic and behavioural responses as in the anuran bufo marinus. in support of this function, behavioural hypothermia was demonstrated in the shore crab carcinus maenas. the animals moved to a cooler environment when exposed to hypoxic conditions. a decrease in preferred temperature of the same magnitude was also found when normoxic animals were injected with ...	1997	9318817
maintenance of motor pattern phase relationships in the ventilatory system of the crab	the central pattern generator responsible for the gill ventilation rhythm in the shore crab carcinus maenas can produce a functional motor pattern over a large (eightfold) range of cycle frequencies. one way to continue to generate a functional motor pattern over such a large frequency range would be to maintain the relative timing (phase) of the motor pattern as cycle frequency changes. this hypothesis was tested by measuring the phase of eight events in the motor pattern from extracellular rec ...	1997	9318763
isolation and characterization of an adipokinetic hormone release-inducing factor in locusts: the crustacean cardioactive peptide.	a methanolic extract of 7000 desert locust (schistocerca gregaria) brains contains several factors that stimulate the in vitro release of adipokinetic hormone (akh) by glandular cells of locust (locusta migratoria and schistocerca gregaria) corpora cardiaca. the most potent one has now been fully identified. matrix-assisted laser desorption ionization mass spectrometry-time of flight analysis revealed a mass of 954.6 da. the primary structure of the peptide, pro-phe-cys-asn-ala-phe-thr-gly-cys-n ...	1997	8977396
evidence for the involvement of 3-oxo-delta 4 intermediates in ecdysteroid biosynthesis.	although the involvement of 3-oxo-delta 4 compounds as intermediates in arthropod ecdysteroid biosynthesis has been postulated for a long time, it has not yet been directly demonstrated. in the present study, 3-oxo-delta 4-steroids have been synthesized and incubated in vitro with dissociated moulting gland cells from the crab carcinus maenas. the tritiated compounds were converted into 3-dehydroecdysone, ecdysone and/or 25-deoxyecdysone, i.e. final ecdysteroids. this means that the 3-oxo-delta ...	1996	8973547
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
neuropeptide-induced inhibition of steroidogenesis in crab molting glands: involvement of cgmp-dependent protein kinase.	in crustaceans, ecdysteroid production by the molting glands (y-organs) is negatively regulated by a neuropeptide, molt-inhibiting hormone (mih). the involvement of cyclic nucleotide-dependent kinases in the mechanism of action of this neuropeptide was investigated with regard to the steroidogenic activity of carcinus maenas y-organs. regardless of the activity level, the major phosphotransferase activity measured in cytosolic fraction was cgmp-dependent, indicating a relatively high cytosolic c ...	1996	8921354
purification, kinetical and molecular characterizations of a serine collagenolytic protease from greenshore crag (carcinus maenas) digestive gland.	a serine collagenolytic protease was purified from a water soluble fraction of greenshore crab digestive gland by acidic precipitation, gel filtration on a sephadex g-50 column, ion-exchange chromatography on a fractogel tsk deae column, immobilized metal ion affinity chromatography (imac) on ida (cu2+) sepharose 6b and ion-exchange chromatography on hyper d column. the molecular mass of the monomeric carcinus serine collagenase (csc) was estimated to be 23,000 by sds page and its isoelectric po ...	1996	8896334
does the n-terminal pyroglutamate residue have any physiological significance for crab hyperglycemic neuropeptides?	a characteristic feature of all crustacean hyperglycemic hormones (chh) is that they are always present in the sinus gland as multiple forms or isoforms. the amino acid sequence of the minor form of chh from the green shore crab, carcinus maenas, was determined by automated microsequencing and ms, and was almost identical to that of the major form, except that the n-terminal residue was glutamine rather than pyroglutamate. limited analysis (electrospray ms and amino acid composition) of the two ...	1996	8841399
crab clockwork: the case for interactive circatidal and circadian oscillators controlling rhythmic locomotor activity of carcinus maenas.	the circalunidian hypothesis that tidal rhythms in coastal animals are controlled by two lunar-day (c.24.8 h) oscillators coupled in antiphase is challenged. rhythmic locomotor activity patterns of the shore crab carcinus maenas, and probably of some other species too, are more economically explained by interacting circadian (c.24 h) and true circatidal (c.12.4 h) physiological oscillators. a testable hypothesis is proposed that combines a circadian promotor and a circatidal inhibitor of locomot ...	1996	8874979
sensory feedback and central afferent interaction in the muscle receptor organ of the crab, carcinus maenas.	1. an interaction exists between two proprioceptive afferent neurons innervating the thoracic-coxal muscle receptor organ (tcmro) of the crab, carcinus maenas. intracellular recordings were made from the extraganglionic regions of the afferents in order to characterize this interaction and its effects on sensory feedback. 2. a current-induced depolarization of the nonspiking t fiber of the tcmro results in a depolarization of the p fiber, a small-diameter (7 microns) neuron innervating the same ...	1996	8871199
sensory characteristics of the p afferent neurone of the crab thoracic-coxal muscle receptor organ.	intracellular recordings were made from the p fibre, the smallest of the three afferent neurones innervating the thoracic-coxal muscle receptor organ of the crab (carcinus maenas). while the two larger afferents are nonspiking, the response of the p fibre to a trapezoidal change in receptor muscle length consists of a single action potential signalling the onset of stretch superimposed on a graded amplitude receptor potential. the p fibre is sensitive to the velocity of the applied stretch, but ...	1996	8765562
infestation of an introduced host, the european green crab, carcinus maenas, by a symbiotic nemertean egg predator, carcinonemertes epialti.	the recent introduction of the european green crab, carcinus maenas, to the west coast of the u.s. has provided an opportunity for host transfer of the symbiotic nemertean egg predator, carcinonemertes epialti, from its native shore crab host, hemigrapsus oregonensis to the exotic c. maenas. two surveys of c. maenas in bodega harbor, california, revealed that, in march 1995 prevalence of c. epialti on c. maenas was significantly lower than on h. oregonensis (11% versus 74%), but in november 1995 ...	1996	8636851
the o-diphenol oxidase activity of arthropod hemocyanin.	arthropod hemocyanin (isolated from the crab carcinus maenas and the lobster homarus americanus) is usually referred to as an oxygen transport-storage protein. the protein, however, also catalyses with low efficiency the oxidation of o-diphenol to quinone, similarly to tyrosinase (monophenol, o-diphenol:oxygen oxidoreductase). the enzymatic parameters of hemocyanin are affected by the aggregation state of the protein; namely v(max) exhibited by a dissociated subunit is one order of magnitude gre ...	1996	8617365
nitrite reductase activity of deoxy carcinus maenas hemocyanin: formation of the half-met derivative.		1996	11666340
apparent water permeability as a physiological parameter in crustaceans	this article reviews the use of apparent water permeability (awp) calculated from measurements of isotope-labelled water flux as a physiological estimate of whole-body water permeability in aquatic invertebrates. the rationale and practices of awp calculations are described in an appendix. awp calculations have provided a wealth of information. however, the validity of the method and therefore also of the information obtained have been questioned. consequently, the use of awp data in discussions ...	1996	9320480
active absorption of na+ and cl- across the gill epithelium of the shore crab carcinus maenas: voltage-clamp and ion-flux studies	mechanisms of active nacl uptake across the posterior gills of the shore crab carcinus maenas were examined using radiochemical and electrophysiological techniques. in order to measure short-circuit current (isc), transepithelial conductance (gte) and area-related unidirectional fluxes of na+ and cl-, single split gill lamellae (epithelium plus cuticle) of hyperregulating shore crabs were mounted in a modified ussing chamber. the negative short-circuit current measured with haemolymph-like nacl ...	1996	9319445
opioid receptor types for endogenous enkephalin in the thoracic ganglion of the crab, carcinus maenas.	in crustaceans, the endogenous opioid peptides, enkephalins, are known to be concentrated in the thoracic ganglion, although they have been demonstrated in all parts of the nervous system. bmax and kd measurements have been obtained for the binding of ligands used to characterize delta- and kappa-type opioid receptors in vertebrates. high- and low affinity binding of [3h] [2-d-pen5-d pen] enkephalin ([3h]dpdpe) has been measured with a kd = 9.2 +/- 2.4 nm, bmax = 153 fmol/mg, and kd = 243 +/- 27 ...	1996	8899815