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Chris M Wood - One of the best experts on this subject based on the ideXlab platform.
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an in vitro study of urea water ion and co2 hco3 transport in the gastrointestinal tract of the dogfish shark squalus acanthias the influence of feeding
The Journal of Experimental Biology, 2013Co-Authors: Hon Jung Liew, Gudrun De Boeck, Chris M WoodAbstract:In vitro gut sac preparations made from the cardiac stomach (stomach 1), pyloric stomach (stomach 2), intestine (Spiral Valve) and colon were used to examine the impact of feeding on transport processes in the gastrointestinal tract of the dogfish shark. Preparations were made from animals that were euthanized after 1-2 weeks of fasting, or at 24-48 h after voluntary feeding on a 3% ration of teleost fish (hake). Sacs were incubated under initially symmetrical conditions with dogfish saline on both surfaces. In comparison to an earlier in vivo study, the results confirmed that feeding caused increases in H(+) secretion in both stomach sections, but an increase in Cl(-) secretion only in stomach 2. Na(+) absorption, rather than Na(+) secretion, occurred in both stomach sections after feeding. All sections of the tract absorbed water and the intestine strongly absorbed Na(+) and Cl(-), regardless of feeding condition. The results also confirmed that feeding increased water absorption in the intestine (but not in the colon), and had little influence on the handling of Ca(2+) and Mg(2+), which exhibited negligible absorption across the tract. However, K(+) was secreted in the intestine in both fasted and fed preparations. Increased intestinal water absorption occurred despite net osmolyte secretion into the mucosal saline. The largest changes occurred in urea and CO2/HCO3(-) fluxes. In fasted preparations, urea was absorbed at a low rate in all sections except the intestine, where it was secreted. Instead of an increase in intestinal urea secretion predicted from in vivo data, feeding caused a marked switch to net urea absorption. This intestinal urea transport occurred at a rate comparable to urea reabsorption rates reported at gills and kidney, and was apparently active, establishing a large serosal-to-mucosal concentration gradient. Feeding also greatly increased intestinal CO2/HCO3(-) secretion; if interpreted as HCO3(-) transport, the rates were in the upper range of those reported in marine teleosts. Phloretin (0.25 mmol l(-1), applied mucosally) completely blocked the increases in intestinal urea absorption and CO2/HCO3(-) secretion caused by feeding, but had no effect on Na(+), Cl(-) or water absorption.
Hon Jung Liew - One of the best experts on this subject based on the ideXlab platform.
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an in vitro study of urea water ion and co2 hco3 transport in the gastrointestinal tract of the dogfish shark squalus acanthias the influence of feeding
The Journal of Experimental Biology, 2013Co-Authors: Hon Jung Liew, Gudrun De Boeck, Chris M WoodAbstract:In vitro gut sac preparations made from the cardiac stomach (stomach 1), pyloric stomach (stomach 2), intestine (Spiral Valve) and colon were used to examine the impact of feeding on transport processes in the gastrointestinal tract of the dogfish shark. Preparations were made from animals that were euthanized after 1-2 weeks of fasting, or at 24-48 h after voluntary feeding on a 3% ration of teleost fish (hake). Sacs were incubated under initially symmetrical conditions with dogfish saline on both surfaces. In comparison to an earlier in vivo study, the results confirmed that feeding caused increases in H(+) secretion in both stomach sections, but an increase in Cl(-) secretion only in stomach 2. Na(+) absorption, rather than Na(+) secretion, occurred in both stomach sections after feeding. All sections of the tract absorbed water and the intestine strongly absorbed Na(+) and Cl(-), regardless of feeding condition. The results also confirmed that feeding increased water absorption in the intestine (but not in the colon), and had little influence on the handling of Ca(2+) and Mg(2+), which exhibited negligible absorption across the tract. However, K(+) was secreted in the intestine in both fasted and fed preparations. Increased intestinal water absorption occurred despite net osmolyte secretion into the mucosal saline. The largest changes occurred in urea and CO2/HCO3(-) fluxes. In fasted preparations, urea was absorbed at a low rate in all sections except the intestine, where it was secreted. Instead of an increase in intestinal urea secretion predicted from in vivo data, feeding caused a marked switch to net urea absorption. This intestinal urea transport occurred at a rate comparable to urea reabsorption rates reported at gills and kidney, and was apparently active, establishing a large serosal-to-mucosal concentration gradient. Feeding also greatly increased intestinal CO2/HCO3(-) secretion; if interpreted as HCO3(-) transport, the rates were in the upper range of those reported in marine teleosts. Phloretin (0.25 mmol l(-1), applied mucosally) completely blocked the increases in intestinal urea absorption and CO2/HCO3(-) secretion caused by feeding, but had no effect on Na(+), Cl(-) or water absorption.
Ian Beveridge - One of the best experts on this subject based on the ideXlab platform.
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eutetrarhynchus pacificus n sp cestoda trypanorhyncha from raja inornata jordan gilbert batoidea rajiformes off the coast of california with comments on congeners
Systematic Parasitology, 2021Co-Authors: Ian Beveridge, Anson V Koehler, Ralph G AppyAbstract:Eutetrarhynchus pacificus n. sp. is described from the Spiral Valve of Raja inornata Jordan & Gilbert off the coast of California, USA. The new species is distinguished from E. ruficollis (Eysenhardt, 1829) and E. leucomelanus (Shipley & Hornell, 1906) in having acraspedote rather than craspedote segments and a saccate rather than a branched uterus. It is distinguished from E. platycephali Palm, 2004 in lacking an enlarged hook in the eighth row of the basal armature and from E. beveridgei Schaeffner, 2013, which has a basal swelling and a distinctive basal armature. A partial redescription of E. ruficollis, the type-species of the genus, is provided based on available museum specimens, highlighting the need for a comprehensive redescription of this species to better define the characteristics of the genus. The presence of an undescribed species in museum collections is also noted. Based on the 28S ribosomal gene, the new species clustered with Dollfusiella in a molecular phylogenetic tree. The delimitation of Eutetrarhynchus and its relationship with Dollfusiella is discussed.
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Review of the genus Progrillotia Dollfus, 1946 (Cestoda: Trypanorhyncha), with a redescription of Progrillotia pastinacae Dollfus, 1946 and description of Progrillotia dasyatidis sp. n.
2015Co-Authors: Ian Beveridge, Lassad Neifar, Louis EuzetAbstract:Abstract. Progrillotia pastinacae Dollfus, 1946 (Cestoda: Trypanorhyncha) is redescribed from the Spiral Valve of Dasyatis pastinaca (Linnaeus) (Dasyatididae) from the coast of France. Progrillotia dasyatidis sp. n. is described from the Spiral Valves of Dasyatis tortonesei Capapé (Dasyatididae) from the Mediterranean in the Gulf of Gabès (Tunisia) and D. pastinaca from the Bassin d’Arcachon (France). The new species differs from congeners in having, on the tentacles, a single rather than two rows of intercalary hooks and fewer testes. The generic definition is emended based upon the new species, the redescription of P. pastinacae Dollfus, 1946 and re-examination of the type specimen of P. louiseuzeti Dollfus, 1969. Important additional characters noted are that the tentacular hooks are solid, a prebulbar organ is present and that there are gland cells attached to the retractor muscle within the bulb. A cladistic analysis suggests that the genus is closely allied with the Eutetrarhynchidae. Progrillotia dollfusi Carvajal et Rego, 1983 is provisionally excluded from the genus as the adult of the species is unknown and a key character of the genus is that the testes are pre-ovarian. The trypanorhynchan cestode subgenus Progrillotia was erected by Dollfus (1946) within the genus Grillotia Guiart, 1927 to accommodate a species of cestode from the Spiral Valve of the stingray Dasyatis pastinaca (Linnaeus, 1758) collected at Concarneau o
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oncomegas aetobatidis sp nov cestoda trypanorhyncha a re description of o australiensis toth campbell schmidt 1992 and new records of trypanorhynch cestodes from australian elasmobranch fishes
Transactions of The Royal Society of South Australia, 2009Co-Authors: Ronald A. Campbell, Ian BeveridgeAbstract:Oncomegas aetobatidis sp. nov. (Trypanorhyncha: Eutetrarhynchidae) is described from the Spiral Valve of the dasyatid ray Aetobatus narinari (Euphrasen, 1790) from the Arafura Sea, Northern Territo...
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oncomegas aetobatidis sp nov cestoda trypanorhyncha a re description of o australiensis toth campbell schmidt 1992 and new records of trypanorhynch cestodes from australian elasmobranch fishes
Transactions of The Royal Society of South Australia, 2009Co-Authors: Ronald A. Campbell, Ian BeveridgeAbstract:AbstractOncomegas aetobatidis sp. nov. (Trypanorhyncha: Eutetrarhynchidae) is described from the Spiral Valve of the dasyatid ray Aetobatus narinari (Euphrasen, 1790) from the Arafura Sea, Northern Territory. The new species is most closely related to O. australiensis Toth, Campbell and Schmidt, 1992 in the number of files of hooks in the metabasal region of the tentacular armature and the presence of post-ovarian testes, but differs in overall dimensions, in the size of the macro-hook in the basal armature and in the number of testes. The mature segment of O. australiensis is described for the first time. Cestodes reported for the first time from Australian waters are: Pterobothrium platycephalum (Shipley & Hornell, 1906) Dollfus, 1930 (Pterobothriidae) from Himantura jenkinsii (Annandale, 1909) and Himantura spParachristianella indonesiensis Palm, 2004 (Eutetrarhynchidae) from Pastinachus sephen (Forsskal, 1775), Himantura undulata (Bleeker, 1852), H. jenkinsii and H. toshi Whitley, 1939, Prochristianel...
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three new genera and seven new species of trypanorhynch cestodes family eutetrarhynchidae from manta rays mobula spp mobulidae from the gulf of california mexico
Folia Parasitologica, 2006Co-Authors: Ronald A. Campbell, Ian BeveridgeAbstract:Three new genera of eutetrarhynchid trypanorhynch cestodes are described from Mobula spp. (Mobulidae) from the Gulf of California, Mexico. Fellicocestus mobulae gen. et sp. n. from the gall bladder of Mobula japonica (Muller et Henle) is distinguished by elongate bothria, a pars bothrialis equal in length to the pars vaginalis, masses of gland cells in the pars vaginalis and an heteromorphous armature in which hook rows arise from a central file of hooks on the bothrial surface of the tentacle and terminate in a central file on the antibothrial surface. Species of Mobulocestus gen. n. occur in the nephridial system and cloaca of rays and are characterized by two bothria, an heteroacanthous armature with hook rows beginning on the bothrial surface and terminating on the antibothrial surface, and by hooks at the beginnings of rows with an apical cavity. M. nephritidis sp. n. and M. lepidoscolex sp. n., both from the nephridial system of Mobula thurstoni (Lloyd) are differentiated by testis number and by the presence of scale-like microtriches on the tegument of the scolex of M. lepidoscolex. M. mollis sp. n., from the cloaca of Mobula thurstoni is distinguished by testis number (97-111 in M. lepidoscolex, 20-22 in M. nephriticus and 48-70 in M. mollis). Hemionchos gen. n. from the Spiral Valve of Mobula spp. has two bothria, an heteroacanthous armature, hook rows arising on the bothrial surface and terminating on the antibothrial surface and hooks at the beginning of rows with an apical cavity. It differs from Mobulocestus in having a distinctive basal armature and both hook files 1 and 1' on the bothrial surface, but has an additional, small, satellite hook adjacent to each hook 1'. H. striatus sp. n. from the Spiral Valve of Mobula thurstoni and M. japonica is differentiated by having a basal armature of closely packed arrays of small, uncinate hooks. H. mobulae sp. n. from the Spiral Valve of Mobula japonica and M. munkiana Notarbartolo di Sciari, differs in testis number and in having large, flattened hooks in the basal armature. H. maior sp. n., from the Spiral Valve of M. japonica, is larger, differing in both the number of testes and in the basal armature.
Patrick J Walsh - One of the best experts on this subject based on the ideXlab platform.
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osmoregulation ionoregulation and acid base regulation by the gastrointestinal tract after feeding in the elasmobranch squalus acanthias
The Journal of Experimental Biology, 2007Co-Authors: Makiko Kajimura, Patrick J Walsh, Carol BuckingAbstract:In order to study the physiological consequences of voluntary feeding in the gastrointestinal tract of a ureotelic marine elasmobranch, dogfish (fasted for 96 h) were sampled at various times up to 360 h after consuming a 5-6% ration of teleost fish (hake) under natural feeding conditions. Digestion and absorption were completed between 120 and 360 h post-feeding. The tissue masses of different segments of the gastrointestinal tract increased and decreased markedly as the chyme moved through, mainly because of fluid engorgement rather than hyperplasia. In fasted dogfish, the cardiac and pyloric stomachs contained only small volumes of highly acidic fluid (pH 1.77+/-1.12, 2.05+/-0.08) similar in composition to seawater. Feeding resulted in gastric pHs of 3.20+/-0.31 and 3.95+/-0.40 at 6 h, followed by slow declines through 60 h. An alkaline tide in the blood also occurred at 6 h. In the face of large changing masses of highly acidic chyme in the stomachs, the pH (6.50+/-0.10), ionic composition and volume of chyme in the intestine (Spiral Valve) were precisely regulated from 6 to 60 h post-feeding at very different values from those in the stomachs, and intestinal HCO3(-) remained low (5.12+/-0.83 mmol l(-1)). The colon was usually empty and its pH constant at 7.20+/-0.16 at all times. Despite the ingestion of strongly hypo-osmotic teleost tissue, the osmolality of the chyme remained in equilibrium with that of the blood plasma in all segments at all times after feeding. Much of the osmotic equilibration was because of the secretion of urea into the chyme, particularly in the intestine. After feeding, gastric fluid concentrations of Na(+) and Mg(2+) declined, K(+) and Ca(2+) increased, whereas Cl(-) exhibited little change, indicating that additional drinking of seawater was minimal. Na(+), K(+), water and especially Cl(-) were absorbed in the intestine, whereas Mg(2+) and Ca(2+) were largely excluded. Our results illustrate the complex integration of digestive and ionoregulatory function in the elasmobranch digestive tract, and marked differences from the teleost pattern.
Ronald A. Campbell - One of the best experts on this subject based on the ideXlab platform.
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oncomegas aetobatidis sp nov cestoda trypanorhyncha a re description of o australiensis toth campbell schmidt 1992 and new records of trypanorhynch cestodes from australian elasmobranch fishes
Transactions of The Royal Society of South Australia, 2009Co-Authors: Ronald A. Campbell, Ian BeveridgeAbstract:Oncomegas aetobatidis sp. nov. (Trypanorhyncha: Eutetrarhynchidae) is described from the Spiral Valve of the dasyatid ray Aetobatus narinari (Euphrasen, 1790) from the Arafura Sea, Northern Territo...
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oncomegas aetobatidis sp nov cestoda trypanorhyncha a re description of o australiensis toth campbell schmidt 1992 and new records of trypanorhynch cestodes from australian elasmobranch fishes
Transactions of The Royal Society of South Australia, 2009Co-Authors: Ronald A. Campbell, Ian BeveridgeAbstract:AbstractOncomegas aetobatidis sp. nov. (Trypanorhyncha: Eutetrarhynchidae) is described from the Spiral Valve of the dasyatid ray Aetobatus narinari (Euphrasen, 1790) from the Arafura Sea, Northern Territory. The new species is most closely related to O. australiensis Toth, Campbell and Schmidt, 1992 in the number of files of hooks in the metabasal region of the tentacular armature and the presence of post-ovarian testes, but differs in overall dimensions, in the size of the macro-hook in the basal armature and in the number of testes. The mature segment of O. australiensis is described for the first time. Cestodes reported for the first time from Australian waters are: Pterobothrium platycephalum (Shipley & Hornell, 1906) Dollfus, 1930 (Pterobothriidae) from Himantura jenkinsii (Annandale, 1909) and Himantura spParachristianella indonesiensis Palm, 2004 (Eutetrarhynchidae) from Pastinachus sephen (Forsskal, 1775), Himantura undulata (Bleeker, 1852), H. jenkinsii and H. toshi Whitley, 1939, Prochristianel...
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three new genera and seven new species of trypanorhynch cestodes family eutetrarhynchidae from manta rays mobula spp mobulidae from the gulf of california mexico
Folia Parasitologica, 2006Co-Authors: Ronald A. Campbell, Ian BeveridgeAbstract:Three new genera of eutetrarhynchid trypanorhynch cestodes are described from Mobula spp. (Mobulidae) from the Gulf of California, Mexico. Fellicocestus mobulae gen. et sp. n. from the gall bladder of Mobula japonica (Muller et Henle) is distinguished by elongate bothria, a pars bothrialis equal in length to the pars vaginalis, masses of gland cells in the pars vaginalis and an heteromorphous armature in which hook rows arise from a central file of hooks on the bothrial surface of the tentacle and terminate in a central file on the antibothrial surface. Species of Mobulocestus gen. n. occur in the nephridial system and cloaca of rays and are characterized by two bothria, an heteroacanthous armature with hook rows beginning on the bothrial surface and terminating on the antibothrial surface, and by hooks at the beginnings of rows with an apical cavity. M. nephritidis sp. n. and M. lepidoscolex sp. n., both from the nephridial system of Mobula thurstoni (Lloyd) are differentiated by testis number and by the presence of scale-like microtriches on the tegument of the scolex of M. lepidoscolex. M. mollis sp. n., from the cloaca of Mobula thurstoni is distinguished by testis number (97-111 in M. lepidoscolex, 20-22 in M. nephriticus and 48-70 in M. mollis). Hemionchos gen. n. from the Spiral Valve of Mobula spp. has two bothria, an heteroacanthous armature, hook rows arising on the bothrial surface and terminating on the antibothrial surface and hooks at the beginning of rows with an apical cavity. It differs from Mobulocestus in having a distinctive basal armature and both hook files 1 and 1' on the bothrial surface, but has an additional, small, satellite hook adjacent to each hook 1'. H. striatus sp. n. from the Spiral Valve of Mobula thurstoni and M. japonica is differentiated by having a basal armature of closely packed arrays of small, uncinate hooks. H. mobulae sp. n. from the Spiral Valve of Mobula japonica and M. munkiana Notarbartolo di Sciari, differs in testis number and in having large, flattened hooks in the basal armature. H. maior sp. n., from the Spiral Valve of M. japonica, is larger, differing in both the number of testes and in the basal armature.
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three new genera of trypanorhynch cestodes from australian elasmobranch fishes
Systematic Parasitology, 2005Co-Authors: Ian Beveridge, Ronald A. CampbellAbstract:Three new genera of trypanorhynch cestodes from Australian elasmobranch fishes collected in the Arafura Sea, off the Northern Territory, are described. Fossobothrium perplexum n. g., n. sp. (Otobothriidae), from the Spiral Valves of Anoxypristis cuspidata (Latham) and Pristis zijsron Bleeker, is similar to the otobothriid genera Pseudotobothrium Dollfus, 1942 and Poecilancistrium Dollfus, 1929 in possessing bothrial pits and a band of hooks on the tentacle, but differs from all known otobothriid genera in having the pits joined by a prominent velum. Iobothrium elegans n. g., n. sp. (Otobothriidae), from the Spiral Valve of Himantura jenkinsi (Annandale), is placed in the Otobothriidae because it possesses bothrial pits, but differs from Otobothrium Linton, 1890 and other genera in lacking intercalary hooks between the principal rows and in possessing a chainette on the external surface of the tentacle in the metabasal region. Oncomegoides celatus n. g., n. sp. (Eutetrarhynchidae), from the Spiral Valve of Dasyatis microps (Annandale) and Himantura jenkinsi, resembles Oncomegas Dollfus, 1929 in possessing two bothria and a megahook on the bothrial surface of the basal armature, but differs in possessing an extra row consisting of four intercalary hooks formed by the overlapping of two intercalary hooks on the external tentacular surface between each of the opposing principal rows and is therefore an atypical heteroacanth.
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Grillotia borealis sp. n. (Cestoda: Trypanorhyncha) from five species of Bathyraja (Rajiformes: Arhynchobatidae) in the North Pacific Ocean with comments on parasite enteric distribution
Folia parasitologica, 2001Co-Authors: Devon B. Keeney, Ronald A. CampbellAbstract:A new trypanorhynch cestode, Grillotia borealis sp. n., is described from the Spiral intestines of softnose skates of the genus Bathyraja collected from subarctic waters of the North Pacific Ocean: B. parmifera (Bean) (type host), B. aleutica (Gilbert) and B. interrupta (Gill et Townsend) from the Bering Sea and B. minispinosa Ishiyama et Ishihara and B. smirnovi (Soldatov et Pavlenko) from the Sea of Okhotsk off Japan. The new species is distinguished from other species of Grillotia by possession of the following combination of characters: four hooks per principal row, hooks 4(4') distinctly separated from hooks 3(3') of principal row, principal rows separated by 13-15 intercalary hooks in 2-3 rows, hooks 2(2') and 3(3') change in form along their respective files, hooks 1(1') do not change in form along the file, a broad band of microhooks on the external tentacular face, intermediary hooks are lacking, absence of a special basal armature, origin of the retractor muscle near middle of the bulb, average scolex ratio of 1 : 3 : 2 : 0.1, and a hermaphroditic sac. Grillotia borealis consistently favoured the most anterior regions of the Spiral intestine. Seventy-one per cent of 21 attached worms occupied the most anterior chamber of the Spiral Valve and 52 per cent were embedded in the anterior surface of the Spiral Valve whorls. Factors which may limit the distribution of G. borealis within the Spiral intestine of its host are discussed. Statistically significant differences occur in the mucosal morphology of B. aleutica and B. parmifera for villus length, diameter, spatial arrangement and number per unit area along the antero-posterior axis of the Spiral intestine. The genus Grillotia Guiart, 1927 consists of cestodes of the order Trypanorhyncha that possess, on the basis of the type species, Grillotia erinaceus (van Beneden, 1858), two bothridia, an atypical heteroacanthous armature with a band of microhooks, postovarian testes, prebulbar organs and bulbs usually longer than the pars bothridialis (Campbell and Beveridge 1994). Currently, 20 species of Grillotia are recognised, eight of which possess four hooks per principal row (Sakanari 1989, Campbell and Beveridge 1993, 1994, Scholz et al. 1993, Palm 1995, Beveridge and Campbell 1998). The genus is cosmopolitan in its distribution and has been recorded from a wide variety of elasmobranch hosts. However, only one species, Grillotia musculara Hart, 1936 from Raja rhina in Puget Sound, has been recorded from a skate in the North Pacific, and only a single species, Grillotia rowei Campbell, 1977, has been reported from a softnose skate belonging to the zoogeographically widespread genus Bathyraja Ishiyama (see Campbell 1977). In this paper, a new species of Grillotia is described from the softnose skates Bathyraja aleutica (Gilbert), B. interrupta (Gill et Townsend) and B. parmifera (Bean) taken in the Bering Sea off Alaska and B. minispinosa Ishiyama et Ishihara and B. smirnovi (Soldatov et Pavlenko) taken from the Sea of Okhotsk, north of Japan. The distribution of the new species within the host's Spiral intestine is also discussed.