| sex hormones in fish. ii. the oestrogens of scyliorhinus caniculus. | | 1963 | 14059567 |
| [on the intestinal absorption of glycocoll in the dog-fish (scyliorhinus canicula)]. | | 1963 | 14104130 |
| [neuro-vasculo-glandular relationships in the hypophysial apparatus of the dog-fish, scyliorhinus caniculus l. (elasmobranch fish)]. | | 1964 | 14250463 |
| [presence of neurosecretory nerve endings on the primary capillaries of the pituitary portal venule system in the spotted dog-fish (scyliorhinus caniculus). electron microscope study]. | | 1962 | 14472395 |
| distribution of choline acetyltransferase immunoreactivity in the brain of an elasmobranch, the lesser spotted dogfish (scyliorhinus canicula). | although the distribution of cholinergic cells is remarkably similar across the vertebrate species, no data are available on more primitive species, such as cartilaginous fishes. to extend the evolutionary analysis of the cholinergic systems, we studied the distribution of cholinergic neurons in the brain and rostral spinal cord of scyliorhinus canicula by immunocytochemistry using an antibody against the enzyme choline acetyltransferase (chat). western blot analysis of brain extracts of dogfish ... | 2000 | 10753304 |
| an investigation of astroglial morphology in torpedo and scyliorhinus. | the distribution and morphology of gfap-immunoreactive cells was investigated in two elasmobranch species, scyliorhinus canicula and torpedo marmorata, in an attempt to distinguish between horstmann's (1954) hypothesis that the presence of cells resembling mammalian astrocytes is a function of the thickness of the ventricular walls, and cajal's (1911) hypothesis that astrocytes are a phylogenetic novelty found only in birds and mammals. two types of gfap-reactive elements were observed, but the ... | 1999 | 10851343 |
| effects of xanthine derivatives on electroretinographic responsiveness. | in view of the use of synthetic propentofylline (ppf) as a protective agent in brain ischemia, its possible side effects on vision capacities have been explored by electroretinography in comparative experiments with theophylline. we used eyecup preparations of small-spotted dogfish sharks and of european eels, particularly suitable for long-lasting experiments. the drug exerted profound but reversible modifications of erg records: (1) a dose-dependent increase of the amplitude and duration of th ... | 2000 | 10854570 |
| goitre in large and small spotted dogfish, scyliorhinus stellaris (l.) and scyliorhinus canicula (l.). | | 2003 | 14710762 |
| the influence of natural surface microtopographies on fouling. | multiple antifouling strategies of marine organisms may consist of combinations of physical, chemical and mechanical mechanisms. in this study, the role of surface microtopography (< 500 microns) of different marine organisms, such as cancer pagurus, mytilus edulis, ophiura texturata and the eggcase of scyliorhinus canicula, has been investigated as a possible component of their defence systems. high resolution resin replicates of these natural surface structures were exposed to natural fouling ... | 2004 | 15079892 |
| antioxidant efficiency and detoxification enzymes in spotted dogfish scyliorhinus canicula. | although elasmobranchs are widely distributed species, commonly found on sandy, gravely or muddy bottoms, several biological aspects of their metabolism still remain poorly investigated. in this work the efficiency of antioxidant system and detoxification enzymes were investigated in the coastal spotted dogfish scyliorhinus canicula and in the red mullet mullus barbatus for comparison with a teleost species. organisms were sampled during a bottom trawl survey and analyzed for the biotransformati ... | 2004 | 15178047 |
| retinal ganglion cell topography in elasmobranchs. | retinal wholemounts are used to examine the topographic distribution of retinal cells within the ganglion cell layer in a range of elasmobranchs from different depths. the retina is examined for regional specializations for acute vision in six species of selachians, galeocerdo cuvieri, hemiscyllium ocellatum, scyliorhinus canicula, galeus melastomus, etmopterus spinax, isistius brasiliensis, one species of batoid, raja bigelowi and one species of chimaera, hydrolagus mirabilis. these species rep ... | 2000 | 10940662 |
| a dii-tracing study of the neural connections of the pineal organ in two elasmobranchs (scyliorhinus canicula and raja montagui) suggests a pineal projection to the midbrain gnrh-immunoreactive nucleus. | the pineal organ of elasmobranchs is an elongated photoreceptive organ. in order to investigate the afferent and efferent connections of the pineal organ of two elasmobranchs, the skate (raja montagui) and the dogfish (scyliorhinus canicula), a fluorescent carbocyanine (dii) was applied to the pineal organ of paraformaldehyde-fixed brains. this application strongly labeled the pineal tract, which formed extensive bilateral projections. in both species, the pinealofugal fibers coursed to the dors ... | 2001 | 11320655 |
| the dipsogenic effect of the renin-angiotensin system in elasmobranch fish. | this study investigated the control of drinking in elasmobranch fish through manipulation of the homologous renin-angiotensin system (ras). the smooth muscle relaxant papaverine was found to increase basal drinking levels in the european lesser-spotted dogfish, scyliorhinus canicula, almost 20-fold. however, this response was significantly reduced with the coadministration of the angiotensin-converting enzyme inhibitor captopril which had no effect when administered alone. captopril was also fou ... | 2001 | 11742513 |
| isolation and characterization of cxc receptor genes in a range of elasmobranchs. | the cxc group of chemokines exert their cellular effects via the cxcr group of g-protein coupled receptors. six cxcr genes have been identified in humans (cxcr1-6), and homologues to some of these have been isolated from a range of vertebrate species. here we isolate and characterize cxcr genes from a range of elasmobranch species. one cxcr1/2 gene fragment isolated from scyliorhinus caniculus (lesser spotted catshark), and two cxcr1/2 copies from each of the elasmobranchs, cetorhinus maximus (b ... | 2005 | 15572071 |
| duality of gonadotropins in gnathostomes. | the glycoprotein hormone alpha subunit and two beta subunits were cloned from the ventral lobe of the pituitary gland of an elasmobranch fish, scyliorhinus canicula. the mature alpha subunit was 96 amino acids long and showed 64-76 amino acid residues in common with alpha subunit sequences of representatives of sarcopterygians (tetrapods and dipnoi) and actinopterigyans (chondrostei and teleostei). the scyliorhinus beta 1 subunit was 115 amino acid long and had characteristics specific to fsh be ... | 2001 | 11742514 |
| molecular cloning and preliminary expression analysis of banded dogfish (triakis scyllia) cc chemokine cdnas by use of suppression subtractive hybridization. | suppression subtractive hybridization was carried out by using cdnas of peripheral white blood cells (pwbcs) of banded dogfish (triakis scyllia) after phorbol 12-myristate 13-acetate (pma) stimulation. the trsc-scya107, mip3alpha1 and mip3alpha2 clones contained an open reading frame encoding 97, 99 and 97 amino acids, respectively. comparison of the deduced amino acids showed that the banded dogfish mip3alpha1 and mip3alpha2 sequences shared 42.3% and 40.0% identity with human scya20, respectiv ... | 2004 | 15592825 |
| the effects of dietary sodium loading on the activity and expression of na, k-atpase in the rectal gland of the european dogfish (scyliorhinus canicula). | cdna fragments of both the alpha- and beta-subunits of the na, k-atpase and a cdna fragment of the secretory form of na-k-cl cotransporter from the european dogfish (scyliorhinus canicula) were amplified and cloned using degenerate primers in rt-pcr. these clones were used along with a scftr cdna from the related dogfish shark, squalus acanthias to characterise the expression of mrnas for these ion transporters in the dogfish rectal gland subsequent to an acute feeding episode. following a singl ... | 2002 | 11818240 |
| feeding ecology of five commercial shark species of the celtic sea through stable isotope and trace metal analysis. | in order to trace their feeding habits, stable carbon and nitrogen isotope ratios (delta15n and delta13c), as well as trace metal concentrations (zn, cd, fe, cu, se and hg) were analysed in the tissues of five commercial shark species from the celtic sea: the tope shark galeorhinus galeus, the black-mouthed catshark galeus melastomus, the starry smooth hound mustelus asterias, the spiny dogfish squalus acanthias and the lesser-spotted dogfish scyliorhinus canicula. our results were compared to p ... | 2005 | 15925404 |
| rostral floor plate (flexural organ) secretes glycoproteins immunologically similar to subcommissural organ glycoproteins in dogfish (scyliorhinus canicula) embryos. | the subcommissural organ of vertebrates secretes glycoproteins into the cerebrospinal fluid of the third cerebral ventricle. this material polymerizes in reissner's fiber. during ontogenetic development, besides the subcommissural organ, the ependyma lining the pontine flexure constitutes an additional reissner's fiber-secreting gland named flexural organ. we have studied the secretion of the flexural organ and the subcommissural organ in dogfish (scyliorhinus canicula) embryos using three diffe ... | 1997 | 9298235 |
| urea transport by hepatocytes and red blood cells of selected elasmobranch and teleost fishes | although urea transport is receiving increased attention in mammalian systems, very little is known about urea transport in fish tissues. this study examined mechanisms of urea transport in red blood cells and hepatocytes from the lesser spotted dogfish (scyliorhinus canicula), atlantic stingray (dasyatis sabina), turbot (scopthalmus maximus), redfish (scianops ocellatus), gulf toadfish (opsanus beta) and oyster toadfish (opsanus tau). urea appeared to be passively distributed in both tissues (i ... | 1994 | 9317893 |
| the energetic cost of activation of white muscle fibres from the dogfish scyliorhinus canicula | the energetic cost of activation was measured during an isometric tetanus of white muscle fibres from the dogfish scyliorhinus canicula. the total heat production by the fibres was taken as a measure of the total energetic cost. this energy consists of two parts. one is due to crossbridge interaction which produces isometric force, and this part varies linearly with the degree of filament overlap in the fibres. the other part of the energy is that associated with activation of the crossbridges b ... | 1997 | 9318167 |
| a reaction-diffusion model can account for the anatomical pattern of the cardiac conal valves in fish | the conus arteriosus of fish bears a variable number of swallownest-like valves arranged in transverse rows. we propose that a reaction-diffusion mechanism coupled with the specific growth dynamics of the conus arteriosus, and probably, with a system of positional information, can account for the pattern formation of the conal valves in these primitive vertebrates. the reaction-diffusion mechanism, according to our hypothesis, would determine the regular arrangement of the places where the endoc ... | 1997 | 9344724 |
| gabaergic system of the pineal organ of an elasmobranch (scyliorhinus canicula): a developmental immunocytochemical study. | the present immunocytochemical study provides evidence of a previously unrecognized, rich, gamma-aminobutyric acid (gaba)-ergic innervation of the pineal organ in the dogfish (scyliorhinus canicula). in this elasmobranch, the pineal primordium is initially detected at embryonic stage 24 and grows to form a long pineal tube by stage 28. glutamic acid decarboxylase (gad)-immunoreactive (-ir) fibers were first observed at stage 26, and by stage 28, thin gad-ir fibers were detectable at the base of ... | 2006 | 16158323 |
| predictions of the time course of force and power output by dogfish white muscle fibres during brief tetani. | the aim of this study was to identify the principal factors that determine the time course of force and power output by muscle during patterns of stimulation and movement similar to those during fish swimming. fully activated, white muscle fibres isolated from dogfish scyliorhinus canicula were used to characterize the force-velocity relationship of the contractile component (cc) and the stress-strain relationship of the passive, elastic component (sec) in series with the cc. a simple model of t ... | 1998 | 9390941 |
| mercury and arsenic speciation in the muscle tissue of scyliorhinus canicula from the mediterranean sea. | | 2005 | 16228876 |
| developmental origin of shark electrosensory organs. | vertebrates have evolved electrosensory receptors that detect electrical stimuli on the surface of the skin and transmit them somatotopically to the brain. in chondrichthyans, the electrosensory system is composed of a cephalic network of ampullary organs, known as the ampullae of lorenzini, that can detect extremely weak electric fields during hunting and navigation. each ampullary organ consists of a gel-filled epidermal pit containing sensory hair cells, and synaptic connections with primary ... | 2006 | 16409384 |
| dogfish hair cells sense hydrostatic pressure. | many marine invertebrates and fish respond to hydrostatic pressure in order to regulate their depth and synchronize their behaviour to tidal cycles. here we investigate the effect of hydrostatic pressure on the vestibular hair cells located in the labyrinth of the dogfish scyliorhinus canicula, and find that it modulates their spontaneous activity and response to angular acceleration. this may explain not only the low resting activity of vertebrate hair cells but also how fish that do not have s ... | 2002 | 11823850 |
| post-transcriptional regulation of cytokine genes in fish: a role for conserved au-rich elements located in the 3'-untranslated region of their mrnas. | the overproduction of cytokines, such us interleukin-1beta (il-1beta) and tumor necrosis factor alpha (tnfalpha), contributes to the pathological complications observed in many inflammatory diseases caused by bacterial endotoxins. the synthesis of these cytokines is tightly regulated at both transcriptional and post-transcriptional levels. post-transcriptional regulation of gene expression depends on specific cis-acting sequences and trans-acting factors. thus, the presence of adenylate- and uri ... | 2007 | 16581132 |
| cardiovascular actions of dogfish urotensin i in the dogfish, scyliorhinus canicula. | a synthetic replicate of dogfish urotensin 1 (u-i), a 41-amino-acid residue peptide isolated from an extract of the caudal spinal cord region of the european spotted dogfish scyliorhinus canicula was prepared in order to study its cardiovascular actions in the species of origin. bolus intraarterial injections of dogfish u-i (0.3-30 nmol/kg body wt) into the celiac artery of unanesthetized dogfish produced a transient fall in arterial blood pressure (p < 0.05 in the dose range 1-3 nmol/kg) follow ... | 1998 | 9473371 |
| distinguishing metabolic heat from condensation heat during muscle recovery. | when a thermopile is used to measure the heat production of isolated muscle, the muscle is surrounded by gas saturated with water vapour, initially in equilibrium with the muscle. after contraction, the osmolarity of the muscle is raised so that it is no longer in equilibrium with the gas around it, and condensation will occur. when artificial muscles of known osmolarity were placed on a thermopile surrounded by gas in equilibrium with a solution of lower osmolarity, their temperature was found ... | 1998 | 9698589 |
| pax6 expression patterns in lampetra fluviatilis and scyliorhinus canicula embryos suggest highly conserved roles in the early regionalization of the vertebrate brain. | we report expression patterns of the pax6 gene in the dogfish scyliorhinus canicula and the lamprey lampetra fluviatilis during neurulation and at the beginning of organogenesis. at the stages studied, both genes display very similar expression domains in the dorsal forebrain, with a sharp posterior boundary at the diencephalon-mesencephalon border, in the hindbrain, excluding the floor plate and the roof plate, and in the spinal cord. the comparison of these expression patterns with those repor ... | 2002 | 11922971 |
| bioaccumulation of heavy metals and radionuclides from seawater by encased embryos of the spotted dogfish scyliorhinus canicula. | encased embryos of spotted dogfish scyliorhinus canicula absorbed six radio-isotopes (241am, 109cd, 57co, 134cs, 54mn and 65zn) directly from seawater during short-term experimental exposure, demonstrating the permeability of the egg-case to these contaminants. embryo to water concentration factors (cfs) ranged from 0.14 for 134cs to 7.4 for 65zn. the 65zn and 57co cfs increased exponentially with embryo length, whereas the cf for 109cd declined with length. among different components of the enc ... | 2006 | 16797035 |
| collagen packing in the dogfish egg case wall. | the collagen which forms the egg case of the dogfish, scyliorhinus canicula, is assembled in a three-dimensional network that results in a very resistant capsule. the capsule presumably accomplishes both a protective and a filtering role for the embryo contained within it. in the present work we have obtained electron micrographs of metal-shadowed, deep-etched replicas of the egg case and we have analyzed the micrographs using computer-based fourier methods. the replicas provide details of the t ... | 1998 | 9724610 |
| the complete nucleotide sequence of the mitochondrial dna of the dogfish, scyliorhinus canicula. | we have determined the complete nucleotide sequence of the mitochondrial dna (mtdna) of the dogfish, scyliorhinus canicula. the 16,697-bp-long mtdna possesses a gene organization identical to that of the osteichthyes, but different from that of the sea lamprey petromyzon marinus. the main features of the mtdna of osteichthyans were thus established in the common ancestor to chondrichthyans and osteichthyans. the phylogenetic analysis confirms that the chondrichthyes are the sister group of the o ... | 1998 | 9725850 |
| body fluid volume regulation in elasmobranch fish. | this review addresses an often overlooked aspect of elasmobranch osmoregulation, i.e., control of body fluid volume. more specifically the review addresses the impact of changes in blood volume in elasmobranchs exposed to different environmental salinities. measurement of blood volume in the european lesser-spotted dogfish, scyliorhinus canicula, following acute and chronic exposure to 80% and 120% seawater (sw) is reported. in 80%, 100% and 120% sw-adapted s. canicula, blood volume was 6.3+/-0. ... | 2007 | 17020815 |
| an hermaphrodite dogfish (scyliorhinus canicula). | | 1924 | 17104026 |
| characterization of selachian egg case collagen. | the egg case of the dogfish scyliorhinus canicula is a remarkable collagenous structure that combines mechanical strength and toughness with high permeability to small molecules and ions. the collagenous lamellae that form over 80% of the thickness of the case wall are secreted by the d-zone of the nidamental (oviducal gland). an acid-soluble collagen extracted from this zone and partially purified ran as a single band on a native gel at ph 4.3. a single band of identical mobility was extracted ... | 1998 | 9784402 |
| distribution of thyrotropin-releasing hormone immunoreactivity in the brain of the dogfish scyliorhinus canicula. | to improve knowledge of the peptidergic systems of elasmobranch brains, the distribution of thyrotropin-releasing hormone-immunoreactive (trhir) neurons and fibers was studied in the brain of the small-spotted dogfish (scyliorhinus canicula l.). in the olfactory bulbs, small granule neurons richly innervated the olfactory glomeruli. in the telencephalic hemispheres, small trhir neurons were observed in the superficial dorsal pallium, whereas trhir fibers were widely distributed in pallial and su ... | 2002 | 12410619 |
| development of catecholaminergic systems in the spinal cord of the dogfish scyliorhinus canicula (elasmobranchs). | the development of catecholamine-synthesizing cells and fibers in the spinal cord of dogfish (scyliorhinus canicula l.) was studied by means of immunohistochemistry using antibodies against tyrosine hydroxylase (th). the only th-immunoreactive (th-ir) cells already present in the spinal cord of stage 26 embryos were of cerebrospinal fluid-contacting (csf-c) type. these cells were the first catecholaminergic neurons of the dogfish cns. the number of these th-ir cells increased very considerably i ... | 2003 | 12711365 |
| distribution and potential role of cytosolic water-soluble phosphodiesters in fish. | the distribution of water-soluble phosphodiesters (wspdes) visible by nuclear magnetic resonance (nmr) in some intact tissues of rainbow trout (oncorhynchus mykiss walbaum) and in perchloric extracts after partial purification was examined by (31)p nmr spectroscopy. the compounds of interest were serine ethanolamine phosphate (sep), threonine ethanolamine phosphate (tep), glycerophosphorylcholine (gpc), and glycerophosphorylethanolamine (gpe). tep and sep were mostly accumulated in the heart and ... | 2003 | 13130434 |
| the developmental expression of foxl2 in the dogfish scyliorhinus canicula. | the foxl2 genes are a subfamily of the fox (forkhead box) gene family. foxl2 is mutated in the disorder blepharophimosis, ptosis, and epicanthus inversus syndrome (bpes), which is characterized by eyelid malformations, and premature ovarian failure (pof). in the mouse expression is seen in the perioptic mesenchyme, developing eyelids, ovary and pituitary. we have isolated a foxl2 cdna from the dogfish scyliorhinus canicula (also known as the lesser spotted catshark), allowing the characterisatio ... | 2007 | 17591462 |
| biphasic hoxd gene expression in shark paired fins reveals an ancient origin of the distal limb domain. | the evolutionary transition of fins to limbs involved development of a new suite of distal skeletal structures, the digits. during tetrapod limb development, genes at the 5' end of the hoxd cluster are expressed in two spatiotemporally distinct phases. in the first phase, hoxd9-13 are activated sequentially and form nested domains along the anteroposterior axis of the limb. this initial phase patterns the limb from its proximal limit to the middle of the forearm. later in development, a second w ... | 2007 | 17710153 |
| actomyosin energy turnover declines while force remains constant during isometric muscle contraction. | energy turnover was measured during isometric contractions of intact and triton-permeabilized white fibres from dogfish (scyliorhinus canicula) at 12 degrees c. heat + work from actomyosin in intact fibres was determined from the dependence of heat + work output on filament overlap. inorganic phosphate (pi) release by permeabilized fibres was recorded using the fluorescent protein mdcc-pbp, n-(2-[1-maleimidyl]ethyl)-7-diethylamino-coumarin-3 carboxamide phosphate binding protein. the steady-stat ... | 2004 | 14565999 |
| characterization of brachyury genes in the dogfish s. canicula and the lamprey l. fluviatilis. insights into gastrulation in a chondrichthyan. | in order to gain insights into the evolution of gastrulation mechanisms among vertebrates, we have characterized a brachyury-related gene in a lamprey, lampetra fluviatilis, and in a chondrichthyan, scyliorhinus canicula. these two genes, respectively termed lft and sct, share with their osteichthyan counterparts prominent expression sites in the developing notochord, the tailbud, but also a transient expression in the prechordal plate, which is likely to be ancestral among vertebrates. in addit ... | 2003 | 14597203 |
| the accumulation of lead and mercury from seawater and their depuration by eggs of the spotted dogfish scyliorhinus canicula (chondrichthys). | radiotracer experiments using (210)pb and (203)hg demonstrated that eggs of the spotted dogfish scyliorhinus canicula absorbed lead and inorganic mercury directly from seawater over 21 days of experimental exposure, attaining total egg concentration factors (cfs) relative to water of approximately 400 for pb and 180 for hg, predominantly (> or =98%) due to their accumulation by the collagenous egg case. the rates of accumulation of both pb and hg by the total egg were significantly (p < 0.0001) ... | 2008 | 18214579 |
| immunocytochemical study of calretinin and calbindin d-28k expression in the retina of three cartilaginous fishes and a cladistian (polypterus). | the distribution of two calcium-binding proteins, calbindin d-28k (cb) and calretinin (cr) was studied in the retina of a cladistian, polypterus senegalus, and three cartilaginous fishes (scyliorhinus canicula, raja undulata and torpedo marmorata). western blot analysis of brain extracts revealed the lack of cross-reactivity of the used antibodies. in polypterus, cb and cr immunoreactivities were observed in some amacrine and ganglion cells, but scarce cells showed cr/cb colocalization. furtherm ... | 2008 | 18331901 |
| description of paeon asymboli n. sp. (copepoda: sphyriidae), parasitic on asymbolus spp. (catsharks) and a new host record for p. australis kabata, 1993. | paeon asymboli n. sp. (copepoda: sphyriidae) is described and illustrated from two female specimens taken from the gills of a grey spotted catshark asymbolus analis (ogilby) and an orange spotted catshark a. rubiginosus (last, gomon & gledhill) (scyliorhinidae) from off southeastern queensland, australia. the key features for identification are: a pear-shaped trunk, longer than it is wide, along with a cephalothorax characterised by two large ventral papillae, projecting laterally and supporting ... | 2003 | 14707509 |
| study of the potential spermatogonial stem cell compartment in dogfish testis, scyliorhinus canicula l. | in the lesser-spotted dogfish (scyliorhinus canicula), spermatogenesis takes place within spermatocysts made up of sertoli cells associated with stage-synchronized germ cells. as shown in testicular cross sections, cysts radiate in maturational order from the germinative area, where they are formed, to the opposite margin of the testis, where spermiation occurs. in the germinative zone, which is located in a specific area between the tunica albuginea of the testis and the dorsal testicular vesse ... | 2008 | 18340468 |
| analysis of epha4 in the lesser spotted catshark identifies a primitive gnathostome expression pattern and reveals co-option during evolution of shark-specific morphology. | the eph family is the largest known group of structurally related receptor tyrosine kinases (rtks). each eph receptor has a specific ephrin ligand, and these function to define spatial boundaries during development. analyses of epha4 in mouse, chick, frog and zebrafish embryos have implicated this gene in a number of developmental processes, including maintenance of segmental boundaries, axon guidance, limb development, neural crest migration and patterning of the ear. in order to determine whic ... | 2004 | 15300436 |
| early development of gabaergic cells of the retina in sharks: an immunohistochemical study with gaba and gad antibodies. | we studied the ontogeny and organization of gabaergic cells in the retina of two elasmobranches, the lesser-spotted dogfish (scyliorhinus canicula) and the brown shyshark (haploblepharus fuscus) by using immunohistochemistry for gamma-aminobutyric acid (gaba) and glutamic acid decarboxylase (gad). both antibodies revealed the same pattern of immunoreactivity and both species showed similar organization of gabaergic cells. gabaergic cells were first detected in neural retina of embryos at stage 2 ... | 2008 | 18524536 |
| distribution and development of glutamic acid decarboxylase immunoreactivity in the spinal cord of the dogfish scyliorhinus canicula (elasmobranchs). | the adult distribution and development of gamma-aminobutyric acid (gaba)-synthesizing cells and fibers in the spinal cord of the lesser spotted dogfish (scyliorhinus canicula l.) was studied by means of immunohistochemistry using antibodies against glutamic acid decarboxylase (gad). complementary immunostaining with antibodies against gaba, tyrosine hydroxylase (th), and huc/hud (members of the hu/elav family of rna-associated proteins) and staining with a reduced silver procedure ("en bloc" bie ... | 2004 | 15349979 |
| the structure and ultrastructure of the sinus venosus in the mature dogfish (scyliorhinus canicula): the endocardium, the epicardium and the subepicardial space. | the sinus venosus of fish is the most caudal chamber of the heart. it is often reduced in teleosts but well developed in elasmobranchs. the sinus venosus of the dogfish (scyliorhinus canicula) is vital, since it harbours key elements such as a little known neuroendocrine system and the nodal tissue. however, the study of its structure is still incomplete. we examined the endocardium, epicardium and subepicardium of the sinus venosus in mature dogfishes. the wall is 100-250 microm thick and compr ... | 2004 | 15533455 |
| the origin of the parathyroid gland. | it has long been held that the parathyroid glands and parathyroid hormone evolved with the emergence of the tetrapods, reflecting a need for new controls on calcium homeostasis in terrestrial, rather than aquatic, environments. developmentally, the parathyroid gland is derived from the pharyngeal pouch endoderm, and studies in mice have shown that its formation is under the control of a key regulatory gene, gcm-2. we have used a phylogenetic analysis of gcm-2 to probe the evolutionary origins of ... | 2004 | 15591343 |
| [nmr-relaxation in hydrated collagen from the spotted dogfish]]. | collagen samples from dog-fish egg case at different water content were studied by the 1h nmr relaxation method. the dependences of the proton spin-lattice and spin-spin relaxation rates on the concentration of water in hydrated native collagen were measured. the fractions of water protons of different mobility and their corresponding spin-spin and spin-lattice relaxation rates were determined in a multi-phase model of water protons in natural biopolymer-water systems. the correlation times were ... | 2005 | 15856978 |
| amp-deaminase in elasmobranch fish: a comparative histochemical and enzymatic study. | amp-deaminase activity was measured in white muscle from a wide range of fish, including one cyclostome, 13 chondrosteans, and one teleost to elucidate the pattern of the amp-deaminase activity in white muscle of fish. compared to a mammalian (rat) muscle extract, low enzyme activities are found in the cyclostome and two elasmobranchs from two families (scyliorhinidae, hexanchidae). in contrast, higher amp-deaminase activities, similar to mammals, are expressed in squalidae, all families of skat ... | 2005 | 15979370 |
| development of the serotoninergic system in the central nervous system of a shark, the lesser spotted dogfish scyliorhinus canicula. | chondrychthyans (cartilaginous fishes) are key to understanding the ancestral gnathostome condition since they provide an outgroup to sarcopterygians and actinopterygians. to gain comparative knowledge about the development of the vertebrate serotoninergic systems, we studied by immunohistochemistry the origin, spatiotemporal organization, and migration patterns of serotonin-containing neurons and the growth of axonal pathways in the central nervous system of a shark, the lesser spotted dogfish. ... | 2008 | 18925650 |
| sequence, circulating levels, and expression of c-type natriuretic peptide in a euryhaline elasmobranch, carcharhinus leucas. | the present study has examined expression and circulating levels of c-type natriuretic peptide (cnp) in the euryhaline bull shark, carcharhinus leucas. complementary dna and deduced amino acid sequence for cnp in c. leucas were determined by race methods. homology of cnp amino acid sequence in c. leucas was high both for procnp and for mature cnp when compared with previously identified elasmobranch cnps. mature cnp sequence in c. leucas was identical to that in triakis scyllia and scyliorhinus ... | 2005 | 15979619 |
| temporal and spatial organization of tyrosine hydroxylase-immunoreactive cell groups in the embryonic brain of an elasmobranch, the lesser-spotted dogfish scyliorhinus canicula. | we have studied the development of catecholaminergic (ca) neuronal groups in the brain of the dogfish scyliorhinus canicula using immunohistochemistry to tyrosine hydroxylase (th). the earliest th-immunoreactive (thir) cells were detected in the primordia of the posterior tubercle and suprachiasmatic nuclei (ptn and scn, respectively) of stage 26 embryos. at stage 28, thir cells were also seen extending between the scn and the ptn at ventral thalamic levels. at stage 30, some thir cerebrospinal ... | 2005 | 16144646 |
| equilibrium of nucleotides in the dogfish brain. | in the past, the results of experiments on the time course of concentration changes of adenylates, phosphocreatine, and free creatine in muscle appeared compatible with an equilibrium hypothesis involving only the lohmann and the myokinase reactions. other reports, however, denied the applicability of the equilibrium hypothesis to the same tissue. the controversy may have been due to the high probability of experimental errors since time sampling was performed at second intervals. we presently t ... | 2005 | 16154919 |
| effects of angiotensin ii and c-type natriuretic peptide on the in situ perfused trunk preparation of the dogfish, scyliorhinus canicula. | the renal roles of physiologically relevant doses of angiotensin ii (ang ii) and c-type natriuretic peptide (cnp) were investigated in the dogfish, scyliorhinus canicula, using an in situ perfused trunk preparation. perfusion with 10(-9) m ang ii resulted in a glomerular antidiuresis and decreases in perfusate flow rate, transport maxima for glucose and the proportion of filtering glomeruli. in addition, the renal clearances and excretion of urea, sodium, and chloride were significantly reduced, ... | 2006 | 16185690 |
| evolution of high-performance swimming in sharks: transformations of the musculotendinous system from subcarangiform to thunniform swimmers. | in contrast to all other sharks, lamnid sharks perform a specialized fast and continuous "thunniform" type of locomotion, more similar to that of tunas than to any other known shark or bony fish. within sharks, it has evolved from a subcarangiform mode. experimental data show that the two swimming modes in sharks differ remarkably in kinematic patterns as well as in muscle activation patterns, but the morphology of the underlying musculotendinous system (red muscles and myosepta) that drives con ... | 2006 | 16429422 |
| residue levels of ddts and toxic evaluation of polychlorinated biphenyls (pcbs) in scyliorhinus canicula liver from the mediterranean sea (italy). | | 2006 | 16643963 |
| a developmental approach to forebrain organization in elasmobranchs: new perspectives on the regionalization of the telencephalon. | it is essential to consider chondrichthyans (cartilaginous fishes) in analyzing ancestral brain organization because this radiation represents the out-group to all other living gnathostomes (jawed vertebrates). it is particularly crucial to understand the evolution of the telencephalon in chondrichthyans, as this structure develops by evagination (as in most other vertebrates), whereas in most osteichthyans (bony fishes), it develops by eversion, a markedly different process. among chondrichthya ... | 2009 | 19729893 |
| observations of crypt neuron-like cells in the olfactory epithelium of a cartilaginous fish. | a new receptor neuron (rn) type was recently described in bony fish olfactory epithelium (oe): the crypt receptor neuron. this name is due to its main feature: the presence, at the apical part, of a deep invagination into which cilia protrude. the presence of this receptor neuron type is well documented in different species of bony fishes but it has never been described in cartilaginous fishes. in this study we demonstrate that crypt neuron-like cells are present in the olfactory epithelium of t ... | 2006 | 16716513 |
| patterns of cell proliferation and rod photoreceptor differentiation in shark retinas. | we studied the pattern of cell proliferation and its relation with photoreceptor differentiation in the embryonic and postembryonic retina of two elasmobranchs, the lesser spotted dogfish (scyliorhinus canicula) and the brown shyshark (haploblepharus fuscus). cell proliferation was studied with antibodies raised against proliferating cell nuclear antigen (pcna) and phospho-histone-h3, and early photoreceptor differentiation with an antibody raised against rod opsin. as regards the spatiotemporal ... | 2010 | 19822206 |
| comparison of the bioaccumulation from seawater and depuration of heavy metals and radionuclides in the spotted dogfish scyliorhinus canicula (chondrichthys) and the turbot psetta maxima (actinopterygii: teleostei). | the bioaccumulation of selected heavy metals and radionuclides ((241)am, (109)cd, (57)co, (51)cr, (134)cs, (54)mn and (65)zn) from seawater was experimentally compared in the chondrichthyan scyliorhinus canicula (spotted dogfish) and the actinopterygian teleost psetta maxima (turbot), of comparable size, age and benthic feeding habits. the speciation of these elements in seawater (salinity 38 per thousand, ph 8.1, temperature 16.5 degrees c) was also calculated to determine their potential bioav ... | 2006 | 16730782 |
| cloning of inos in the small spotted catshark (scyliorhinus canicula). | the first cartilaginous fish inos gene has been cloned in the small spotted catshark, scyliorhinus canicula. the cdna was 4568 bp long, with a 3375 bp open reading frame encoding a protein of 1125 amino acids and a predicted molecular mass of 127.8 kda. the catshark translation had 77% amino acid similarity with chicken inos and 70-73% similarity with known teleost i nos molecules. the various co-factor binding sites were well conserved, with the calmodulin site hydrophobicity profile noticeable ... | 2006 | 16876672 |
| isometric and isovelocity contractile performance of red muscle fibres from the dogfish scyliorhinus canicula. | maximum isometric tetanic force produced by bundles of red muscle fibres from dogfish, scyliorhinus canicula (l.), was 142.4+/-10.3 kn m(-2) (n=35 fibre bundles); this was significantly less than that produced by white fibres 289.2+/-8.4 kn m(-2) (n=25 fibre bundles) (means +/- s.e.m.). part, but not all, of the difference is due to mitochondrial content. the maximum unloaded shortening velocity, 1.693+/-0.108 l(0) s(-1) (n=6 fibre bundles), was measured by the slack-test method. l(0) is the len ... | 2002 | 12000803 |
| hunt warm, rest cool: bioenergetic strategy underlying diel vertical migration of a benthic shark. | 1. diel vertical migration (dvm) is a widespread phenomenon among marine and freshwater organisms and many studies with various taxa have sought to understand its adaptive significance. among crustacean zooplankton and juveniles of some fish species dvm is accepted widely as an antipredator behaviour, but little is known about its adaptive value for relatively large-bodied, adult predatory fish such as sharks. moreover, the majority of studies have focused on pelagic forms, which raises the ques ... | 2006 | 16903055 |
| evolution of axis specification mechanisms in jawed vertebrates: insights from a chondrichthyan. | the genetic mechanisms that control the establishment of early polarities and their link with embryonic axis specification and patterning seem to substantially diverge across vertebrates. in amphibians and teleosts, the establishment of an early dorso-ventral polarity determines both the site of axis formation and its rostro-caudal orientation. in contrast, amniotes retain a considerable plasticity for their site of axis formation until blastula stages and rely on signals secreted by extraembryo ... | 2007 | 17440610 |
| accumulation and transport behaviour of 241americium, 60cobalt and 134cesium by eggs of the spotted dogfish scyliorhinus canicula. | an experimental study examined the 96-h net influx from seawater of the anthropogenic radionuclides (241)am, (60)co and (134)cs through the egg-case of the spotted dogfish scyliorhinus canicula. net influx directly through the wall of the egg-case was greatest for (134)cs, then (241)am and lastly (60)co. within the egg-case wall itself the measured concentration factors (cfs) and their gradients in the external, median and internal layers showed that for both (241)am and (60)co they were >10(3) ... | 2007 | 17467014 |
| phylogenetic consistencies among chondrichthyan and teleost fishes in their bioaccumulation of multiple trace elements from seawater. | multi-tracer experiments determined the accumulation from seawater of selected radioactive trace elements (mn-54, co-60, zn-65, cs-134, am-241, cd-109, ag-110m, se-75 and cr-51) by three teleost and three chondrichthyan fish species to test the hypothesis that these phylogenetic groups have different bioaccumulation characteristics, based on previously established contrasts between the carcharhiniform chondrichthyan scyliorhinus canicula (dogfish) and the pleuronectiform teleost psetta maxima (t ... | 2010 | 20471062 |
| responses to moving visual stimuli in pretectal neurons of the small-spotted dogfish (scyliorhinus canicula). | single-unit recordings were performed from a retinorecipient pretectal area (corpus geniculatum laterale) in scyliorhinus canicula. the function and homology of this nucleus has not been clarified so far. during visual stimulation with a random dot pattern, 45 (35%) neurons were found to be direction selective, 10 (8%) were axis selective (best neuronal responses to rotations in both directions around one particular stimulus axis), and 75 (58%) were movement sensitive. direction-selective respon ... | 2008 | 17977925 |
| mercury bioaccumulation in the spotted dogfish (scyliorhinus canicula) from the atlantic ocean. | the annual and life-cycle mercury bioaccumulation pattern in selected tissues of the economically relevant elasmobranchii species scyliorhinus canicula was studied, and the risks associated with its consumption evaluated. preferential mercury bioaccumulation occurred in muscle tissue, and followed the order muscle>heart>liver>gills>pancreas. total mercury in muscle tissue ranged from 0.13mgkg(-1) (wwt) in 1+year old males to 0.8mgkg(-1) (wwt) in 8+ year old mature females, with no significant di ... | 2010 | 20541227 |
| anticoagulant activity of a dermatan sulfate from the skin of the shark scyliorhinus canicula. | a dermatan sulfate isolated from the shark scyliorhinus canicula skin by enzymatic digestion followed by purification with anion exchange chromatography was identified by chondroitinase and nitrous acid treatment and partially characterized by fourier-transform infrared spectroscopy. dermatan sulfate was the major glycosaminoglycan and represented 75% of the polysaccharide fraction in the sharkskin. this dermatan sulfate had a 38.6 kda average molecular weight and 23% sulfate content. the antico ... | 2010 | 20581662 |
| early palaeozoic dentine and patterned scales in the embryonic catshark tail. | regular scale patterning, restricted to the caudalmost tail and organized into two opposing rows on each side of the tail, is observed in few chondrichthyans. these evenly spaced scales, in dorsal and ventral rows, develop in an iterative sequence from the caudal tip, either side of the notochord. they are subsequently lost as a scattered pattern of placoid scales develops on the body and fins. an identical organized pattern is observed in tail scales of scyliorhinus canicula (catshark), where t ... | 2008 | 18055413 |
| tangentially migrating gabaergic cells of subpallial origin invade massively the pallium in developing sharks. | we studied the development of the gabaergic system in the telencephalon of the dogfish scyliorhinus canicula using gaba and glutamate decarboxylase (gad) immunocytochemistry. the earliest gaba-expressing cells appeared in the basal telencephalon (subpallium) of stage 24 embryos. shortly after, the subpallium showed abundant gaba-expressing neuroblasts near the meningeal surface or migrating radially in the neuroepithelium. the limit between the gaba-expressing region and the remainder of the tel ... | 2008 | 18331906 |
| expression of foxc, foxf, foxl1, and foxq1 genes in the dogfish scyliorhinus canicula defines ancient and derived roles for fox genes in vertebrate development. | in the human genome, members of the foxc, foxf, foxl1, and foxq1 gene families are found in two paralagous clusters. here we characterize all four gene families in the dogfish scyliorhinus canicula, a member of the cartilaginous fish lineage that diverged before the radiation of osteichthyan vertebrates. we identify two foxc genes, two foxf genes, and single foxq1 and foxl1 genes, demonstrating cluster duplication preceded the radiation of gnathostomes. the expression of all six genes was analyz ... | 2008 | 18498098 |
| demonstration of bone resorbing cells in elasmobranchs: comparison with osteoclasts. | we have previously shown that elasmobranchs-characterized by a partially calcified cartilaginous endoskeleton-presented a bony vertebral arch containing osteoblasts, osteocytes and resorbing cells. the aim of this study is to test the ability of elasmobranchs to resorb bone tissue. the subcutaneous implantation in dogfish (scyliorhinus canicula) of devitalized mineral-containing bone particles, obtained from a bony fish (the eel, anguilla anguilla) resulted, after 21 2 months, in the formation o ... | 1989 | 18620290 |
| occurrence of neuropeptides and tyrosine hydroxylase in the olfactory epithelium of the lesser-spotted catshark (scyliorhinus canicula linnaeus, 1758). | immunohistochemical studies using antisera against various neuropeptides (substance p, vasoactive intestinal polypeptide, and cholecystokinin octapeptide) and tyrosine hydroxylase revealed both olfactory sensory neuron (osn) polymorphisms and transepithelial-subepithelial nerves in the olfactory epithelium of the cartilaginous fish, scyliorhinus canicula. this study provides the first evidence of three morphological types of osns within the olfactory epithelium of cartilaginous fish that are sim ... | 2010 | 20951411 |
| interaction of collagen with hydrophobic protein granules in the egg capsule of the dogfish scyliorhinus canicula. | the egg capsule of the dogfish is a composite material containing collagenous fibrils and 2 mum spherical hydrophobic protein granules. the latter appear to owe much of their hydrophobicity to an exceptionally high tyrosine content (approximately 20% of total amino acid residues). the hydrophobic component appears to form as an emulsion in the secretory granules of the d and e zone gland cells of the nidamental gland. droplets of the hydrophobic material appear to become coated with remarkably r ... | 1994 | 18621266 |
| characterization of new medium-chain alcohol dehydrogenases adds resolution to duplications of the class i/iii and the sub-class i genes. | four additional variants of alcohol and aldehyde dehydrogenases have been purified and functionally characterized, and their primary structures have been determined. the results allow conclusions about the structural and evolutionary relationships within the large family of mdr alcohol dehydrogenases from characterizations of the pigeon (columba livia) and dogfish (scyliorhinus canicula) major liver alcohol dehydrogenases. the pigeon enzyme turns out to be of class i type and the dogfish enzyme ... | 2011 | 21329683 |
| the dogfish scyliorhinus canicula: a reference in jawed vertebrates. | introductiondue to their large size and long generation times, chondrichthyans have been largely ignored by geneticists. however, their key phylogenetic position makes them ideal subjects to study the molecular bases of the important morphological and physiological innovations that characterize jawed vertebrates. such analyses are crucial to understanding the origin of the complex genetic mechanisms unraveled in osteichthyans. the small spotted dogfish scyliorhinus canicula, a representative of ... | 2008 | 21356737 |
| regionalization of the shark hindbrain: a survey of an ancestral organization. | cartilaginous fishes (chondrichthyans) represent an ancient radiation of vertebrates currently considered the sister group of the group of gnathostomes with a bony skeleton that gave rise to land vertebrates. this out-group position makes chondrichthyans essential in assessing the ancestral organization of the brain of jawed vertebrates. to gain knowledge about hindbrain evolution we have studied its development in a shark, the lesser spotted dogfish scyliorhinus canicula by analyzing the expres ... | 2011 | 21519383 |
| some observations on the collagen fibrils of the egg capsule of the dogfish, scyliorhinus canicula. | the egg capsule of the dogfish scyliorhinus canicula is a collagenous material with a laminated, plywood (orthogonal) construction. the collagen fibrils which constitute the bulk of the egg capsule wall have a unique, highly ordered structure (knight and hunt, 1974; 1976, 1986; gathercole et al., 1993) which is thought to represent a smectic a liquid crystalline phase (knight et al., 1993). the egg capsule is extremely strong and chemically inert (hunt, 1985). it is stored, secreted and formed b ... | 1994 | 18621272 |
| the effect of ph on fibrillogenesis of collagen in the egg capsule of the dogfish, scyliorhinus canicula. | the collagen of the egg capsule of the dogfish, scyliorhinus canicula is stored and secreted by the secretory cells of the d-zone of the nidamental gland (rusaouën-innocent, 1990b). the collagen appears to pass through several morphologically distinct textures during storage, secretion and fibril formation which may represent different lyotropic liquid crystalline phases (knight et al., 1993). in the present communication we report evidence that a fall in hydrogen ion concentration induces fibri ... | 1994 | 18621285 |
| xenobiotic metabolism markers in marine fish with different trophic strategies and their relationship to ecological variables. | nine fish species of commercial interest from six teleost families and two species of elasmobranchs were selected for characterisation of hepatic biomarkers used in early-warning assessment of pollutant exposure. the sampling was carried out in front of the barcelona coast (nw mediterranean) during december 2006 at shelf (53 m) and slope (660 m) depths. the enzymes considered included the antioxidant defence catalase (cat) and glutathione reductase (gr), phase i ethoxyresorufin o-deethylase (ero ... | 2009 | 18708160 |
| first detection of olfactory marker protein (omp) immunoreactivity in the olfactory epithelium of a cartilaginous fish. | olfactory marker protein (omp) is a protein expressed in the mature olfactory and vomeronasal neurons of many vertebrates, such as mammals, amphibians and bony fishes. aim of this work was to investigate the omp expression in the olfactory epithelium of the shark scyliorhinus canicula (linnaeus, 1758), by immunohistochemistry (ihc). immunoreactivity was detected in the olfactory receptor neurons, in the crypt neurons and in the nerve fibers below the epithelium. although very little is known abo ... | 2007 | 17174032 |
| a molecular analysis of neurogenic placode and cranial sensory ganglion development in the shark, scyliorhinus canicula. | in order to gain insight into the evolution of the genetic control of the development of cranial neurogenic placodes and cranial sensory ganglia in vertebrates, we cloned and analysed the spatiotemporal expression pattern of six transcription factor genes in a chondrichthyan, the shark scyliorhinus canicula (lesser-spotted dogfish/catshark). as in other vertebrates, neurod is expressed in all cranial sensory ganglia. we show that pax3 is expressed in the profundal placode and ganglion, strongly ... | 2007 | 17234174 |
| calretinin-immunoreactive systems in the cerebellum and cerebellum-related lateral-line medullary nuclei of an elasmobranch, scyliorhinus canicula. | calretinin immunohistochemistry was used to study the organization of some cerebellar structures and lateral line medullary nuclei of an elasmobranch, the lesser-spotted dogfish scyliorhinus canicula. in the cerebellar molecular layer, stellate cells are strongly calretinin-immunoreactive (cr-ir). perikarya and dendrites of purkinje cells are contacted by numerous stellate cell small cr-ir boutons. some purkinje cell perikarya are contacted by cr-ir climbing fibers forming complex axo-somatic co ... | 2009 | 18929640 |
| reiterative pattern of sonic hedgehog expression in the catshark dentition reveals a phylogenetic template for jawed vertebrates. | for a dentition representing the most basal extant gnathostomes, that of the shark can provide us with key insights into the evolution of vertebrate dentitions. to detail the pattern of odontogenesis, we have profiled the expression of sonic hedgehog, a key regulator of tooth induction. we find in the catshark (scyliorhinus canicula) that intense shh expression first occurs in a bilaterally symmetrical pattern restricted to broad regions in each half of the dentition in the embryo jaw. as in the ... | 2009 | 19141424 |
| towards a synthetic view of axis specification mechanisms in vertebrates: insights from the dogfish. | the genetic mechanisms, which control axis specification, apparently extensively diverge across vertebrates. in amphibians and teleosts, they are tightly linked to the establishment of an early dorso-ventral polarity. this polarity has no equivalent in amniotes, which unlike the former, retain a considerable plasticity for their site of axis formation until blastula stages and rely on signals secreted by extra-embryonic tissues for the establishment of their early rostro-caudal pattern. in order ... | 2009 | 19281952 |
| heterochronic shift in hox-mediated activation of sonic hedgehog leads to morphological changes during fin development. | we explored the molecular mechanisms of morphological transformations of vertebrate paired fin/limb evolution by comparative gene expression profiling and functional analyses. in this study, we focused on the temporal differences of the onset of sonic hedgehog (shh) expression in paired appendages among different vertebrates. in limb buds of chick and mouse, shh expression is activated as soon as there is a morphological bud, concomitant with hoxd10 expression. in dogfish (scyliorhinus canicula) ... | 2009 | 19365553 |
| dominance of dietary intake of metals in marine elasmobranch and teleost fish. | metal accumulation in marine fish is a global public health concern, because the consumption of seafood provides the largest dose of many toxic metals to humans. while water quality criteria often rely on aqueous exposures of metals to fish in developing safety guidelines, it is increasingly recognized that marine fish obtain an important fraction of their metal body burden from their diet. using experimental data, we modeled the accumulation of six metals (am, cd, cs, co, mn, zn) from diet and ... | 2009 | 19580992 |
| structural analysis of chondroitin sulfate from scyliorhinus canicula: a useful source of this polysaccharide. | chondroitin sulfate (cs), a constituent of proteoglycans, is a key component of the connective tissues and it is widely used as a precautionary drug for joint diseases; for this reason, the increased demand of this polysaccharide has posed the problem to identify new and secure sources of this product. in this context, cs from the cartilage of the lesser spotted dogfish (scyliorhinus canicula, a cartilaginous fish) was isolated and investigated through chemical and spectroscopical techniques. th ... | 2009 | 19696233 |
| immunolocalization of g-protein alpha subunits in the olfactory system of the cartilaginous fish scyliorhinus canicula. | in the olfactory and vomeronasal systems of vertebrates, the morphology of the receptor neurons, the receptor gene family they express, the g-protein coupled with the receptor (in particular the g-protein alpha subunit), and their projection to the olfactory bulb are correlated. much information about this complicated system have been collected in different groups, but nothing is known about chondrichthyes. in this work, the presence and distribution of immunoreactivity for different types of g- ... | 2009 | 19768751 |
| muscular cholinesterase activities and lipid peroxidation levels as biomarkers in several mediterranean marine fish species and their relationship with ecological variables. | muscular cholinesterase activities, as potential markers of neurotoxic exposure, and lipid peroxidation levels, indicative of oxidative stress damage, both currently used in early-warning pollution monitoring, were characterised in eighteen fish species of ecologic and/or economic importance. these species comprise five orders and eleven families of teleosts and two species of elasmobranchs, feed using different strategies (benthic, epibenthic, endobenthic and pelagic), belong to different troph ... | 2010 | 20022635 |
| temporal analysis of electroretinographic responses in fishes with rod-dominated and mixed rod-cone retina. | photoreceptor content of fish retinas could be accessed by comparative electroretinographic (erg) studies using flickering light stimuli that could separate rod-mediated vision where critical flicker frequency (cff, frequency when the eye loses its ability to resolve individual light pulses) is usually less than 15 hz from cone-mediated vision. four fish species inhabiting different photic environments (small-spotted dogfish shark--scyliorhinus canicula, eel--anguilla anguilla, painted comber--s ... | 2009 | 20037193 |
| metal accumulation and metallothionein induction in the spotted dogfish scyliorhinus canicula. | recent studies indicate that elasmobranch fish respond differently to metal exposure than marine teleosts. accumulation rates can be high, which despite the fact that normal background levels for metals in the marine environment are low, is worrying due to the long life span and late fecundity of most shark. the goals of the present study were to examine differences in accumulation rates and toxicity of a range of metals at equimolar concentrations (10microm) in the mediterranean or spotted dogf ... | 2010 | 20044020 |
| effect of phosphate and temperature on force exerted by white muscle fibres from dogfish. | effects of pi (inorganic phosphate) are relevant to the in vivo function of muscle because pi is one of the products of atp hydrolysis by actomyosin and by the sarcoplasmic reticulum ca(2+) pump. we have measured the pi sensitivity of force produced by permeabilized muscle fibres from dogfish (scyliorhinus canicula) and rabbit. the activation conditions for dogfish fibres were crucial: fibres activated from the relaxed state at 5, 12, and 20 degrees c were sensitive to pi, whereas fibres activat ... | 2010 | 20084431 |