Regobothrium microhamulinum n. gen. and n. sp. (Bothriocephalidea: Bothriocephalidae) is proposed to accommodate a new cestode from flatfish Catathyridium jenynsii (Chabanaud, 1922) (Pleuronectiformes: Acharidae; type host) and another 3 freshwater fishes of the orders Characiformes, Cyprinodontiformes, and Siluriformes in the Neotropical Region. The new genus is placed in the Bothriocephalidae because it possesses medioventral uterine and mediodorsal genital pores and a follicular vitellarium. Regobothrium n. gen. is characterized by possessing a tiny, slightly subovate scolex narrower than the strobila, with an apical disc armed with 2 semicircles of 15-17 tiny hooks in each and an acraspedote strobila. Regobothrium n. gen. differs from all bothriocephalid cestodes that have a scolex armed with hooks by their small size (maximum length less than 20 μm) and a triangular shape with the basal part (handle or basal plate) shorter than the distal coniform part (blade). In the other hooked bothriocephalids, hooks have a longer handle than a blade. Regobothrium microhamulinum n. gen. and n. sp. is the third bothriocephalidean cestode described from freshwater teleosts in South America but the first out of Patagonia. Molecular phylogenetics consider Regobothrium as a member of a lineage consisting of (up to now exclusively) freshwater bothriocephalids from the Ethiopian biogeographic region, thus indicating Gondwanan relationship.
- MeSH
- Cestoda anatomie a histologie klasifikace ultrastruktura MeSH
- Characiformes parazitologie MeSH
- Cyprinodontiformes parazitologie MeSH
- fylogeneze MeSH
- mikroskopie elektronová rastrovací MeSH
- nemoci ryb parazitologie MeSH
- platýsi parazitologie MeSH
- sladká voda MeSH
- sumci parazitologie MeSH
- tropické klima MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Brazílie MeSH
- Etiopie MeSH
- Jižní Amerika MeSH
Management boundaries that define populations or stocks of fish form the basis of fisheries planning. In the Arctic, decreasing sea ice extent is driving increasing fisheries development, highlighting the need for ecological data to inform management. In Cumberland Sound, southwest Baffin Island, an indigenous community fishery was established in 1987 targeting Greenland halibut (Reinhardtius hippoglossoides) through the ice. Following its development, the Cumberland Sound Management Boundary (CSMB) was designated and a total allowable catch (TAC) assigned to the fishery. The CSMB was based on a sink population of Greenland halibut resident in the northern section of the Sound. Recent fishing activities south of the CSMB, however, raised concerns over fish residency, the effectiveness of the CSMB and the sustainability of the community-based winter fishery. Through acoustic telemetry monitoring at depths between 400 and 1200 m, and environmental and fisheries data, this study examined the movement patterns of Greenland halibut relative to the CSMB, the biotic and abiotic factors driving fish movement and the dynamics of the winter fishery. Greenland halibut undertook clear seasonal movements between the southern and northern regions of the Sound driven by temperature, dissolved oxygen, and sea ice cover with most fish crossing the CSMB on an annual basis. Over the lifespan of the fishery, landfast ice cover initially declined and then became variable, limiting accessibility to favored fisher locations. Concomitantly, catch per unit effort declined, reflecting the effect of changing ice conditions on the location and effort of the fishery. Ultimately, these telemetry data revealed that fishers now target less productive sites outside of their favored areas and, with continued decreases in ice, the winter fishery might cease to exist. In addition, these novel telemetry data revealed that the CSMB is ineffective and led to its relocation to the entrance of the Sound in 2014. The community fishery can now develop an open-water fishery in addition to the winter fishery to exploit the TAC, which will ensure the longevity of the fishery under projected climate-change scenarios. Telemetry shows great promise as a tool for understanding deep-water species and for directly informing fisheries management of these ecosystems that are inherently complex to study.
- MeSH
- migrace zvířat MeSH
- oceány a moře MeSH
- platýs * MeSH
- rozšíření zvířat * MeSH
- rybářství * MeSH
- technologie dálkového snímání MeSH
- zachování přírodních zdrojů metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Arktida MeSH
- Kanada MeSH
- oceány a moře MeSH
For teleost fish fertilisation, sperm must proceed through a small opening on the egg surface, referred to as the micropyle. In this paper, we have used boundary element simulations to explore whether the hydrodynamic attraction between sperm and a fish egg can be a sperm guidance cue. Hydrodynamical egg-sperm interactions alone do not increase the chances of an egg encounter, nor do they induce surface swimming for virtual turbot fish sperm across smooth spheres with a diameter of 1mm, which is representative of a turbot fish egg. When a repulsive surface force between the virtual turbot sperm and the egg is introduced, as motivated by surface charge and van-der-Waals interactions for instance, we find that extended surface swimming of the virtual sperm across a model turbot egg occurs, but ultimately the sperm escapes from the egg. This is due to the small exit angle of the scattering associated with the initial sperm-egg interaction at the egg surface, leading to a weak drift away from the egg, in combination with a weak hydrodynamical attraction between both gametes, though the latter is not sufficient to prevent eventual escape. The resulting transience is not observed experimentally but is a detailed quantitative difference between theory and observation in that stable surface swimming is predicted for eggs with radii larger than about 1.8mm. Regardless, the extended sperm swimming trajectory across the egg constitutes a two-dimensional search for the micropyle and thus the egg is consistently predicted to provide a guidance cue for sperm once they are sufficiently close. In addition, the observation that the virtual turbot sperm swims stably next to a flat plane given repulsive surface interactions, but does not swim stably adjacent to a turbot-sized egg, which is extremely large by sperm-lengthscales, also highlights that the stability of sperm swimming near a boundary is very sensitive to geometry.
- MeSH
- algoritmy MeSH
- biofyzikální jevy MeSH
- hydrodynamika MeSH
- interakce spermie a vajíčka fyziologie MeSH
- motilita spermií * MeSH
- oscilometrie MeSH
- platýsi fyziologie MeSH
- počítačová simulace MeSH
- pohyb MeSH
- spermie fyziologie MeSH
- teoretické modely MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Halibut (Hippoglossus hippoglossus) and shrimps (Pandalus borealis) are regular foodstuffs for communities in northern Norway and important species for the coastal fishing industry. This is the first study to present a comprehensive overview of the contaminant status of these species, with emphasis on unregulated perfluoroalkylated substances (PFAS). The contaminant concentrations were low and within tolerable levels for human dietary exposure. Median Σpolychlorinated biphenyls (PCB) were 4.9 and 2.5ng/g ww for halibut and unpeeled shrimps, respectively. Concentrations of perfluorooctane sulfonate (PFOS) - the most abundant PFASs - were 0.9 and 2.7ng/g ww in halibut and shrimp, respectively. The halibut fillets were dominated by PCBs, which contributed to 50% of the total POPs load, followed by ΣDDTs; 26% and PFASs (18%), whereas shrimps were dominated by PFASs (74%). ΣPBDEs (polybrominated diphenyl ethers) contributed to 1-4% of the total POP load. Local sources are not contributing significantly to the contaminant burden in these species.
- MeSH
- chemické látky znečišťující vodu analýza metabolismus MeSH
- dieta statistika a číselné údaje MeSH
- fluorokarbony metabolismus MeSH
- halogenované difenylethery analýza metabolismus MeSH
- kontaminace potravin statistika a číselné údaje MeSH
- kyseliny alkansulfonové analýza metabolismus MeSH
- lidé MeSH
- platýs metabolismus MeSH
- polychlorované bifenyly analýza MeSH
- potrava z moře (živočišná) statistika a číselné údaje MeSH
- průzkumy a dotazníky MeSH
- ryby MeSH
- vystavení vlivu životního prostředí statistika a číselné údaje MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Norsko MeSH
A new species of Chondracanthidae (Copepoda: Cyclopoida), Heterochondria orientalis sp. n., is described based on specimens of both sexes collected from the gill rakers and the inner side of the operculum of the many-banded sole, Zebrias fasciatus (Basilewsky), from the Yellow Sea, Korea. The new species resembles most closely H. zebriae (Ho, Kim et Kuman, 2000), but can be distinguished from this species and other congeners by the shape of the trunk and length of the antenna, the number of teeth on the mandible and the terminal process of the maxilla, and the structure of the male antennule and maxilliped. Heterochondria orientalis is the first copepod species reported from Z. fasciatus and the first heterochondrid species reported from sole fishes in the Northwest Pacific. A key to distinguish all 10 nominal species of the genus is provided.
- MeSH
- Copepoda anatomie a histologie klasifikace MeSH
- nemoci ryb epidemiologie parazitologie MeSH
- parazitární nemoci u zvířat epidemiologie parazitologie MeSH
- platýsi * MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Korejská republika MeSH
A new copepod species, Acanthochondria sagitta sp. n., is described based on specimens collected from the flounder Xystreurys rasile (Jordan) (Pleuronectiformes, Paralichthyidae), caught in the coastal waters off Necochea, Buenos Aires Province, Argentina. The new species differs from its congeners by the following combination of characters: presence of three pairs of cephalic outgrowths; the triangular shape of the trunk with diverging postero-lateral processes; leg 2 of an intermediate shape between Types C and D, which projects laterally from the trunk, and Type B-V antennule bearing two proximal processes (one ventral and one dorsal) on the swollen basal portion.
- MeSH
- Copepoda anatomie a histologie klasifikace MeSH
- financování organizované MeSH
- infestace ektoparazity parazitologie veterinární MeSH
- nemoci ryb parazitologie MeSH
- platýs parazitologie MeSH
- žábry parazitologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Geografické názvy
- Argentina MeSH
Philometra overstreeti Moravec et de Buron, 2006 and Philomnetroides paralichthydis Moravec et de Buron, 2006 are common parasites of the southern flounder, Paralichthys lethostigma Jordan et Gilbert. Because the life cycles of these parasites are unknown, our goal was to assess whether species of copepod commonly found in our estuaries could serve as intermediate hosts for these philometrids. Individuals of five species of copepods were collected and exposed to L1 larvae of each philometrid species. The cyclopoid Oithlona colcarva Bowman was the only species to become successfully infected. Successive moulting of philometrid larvae in the haemocoel of the copepods was studied using transmission electron microscopy. At 23 degrees C the moult from L1 to L2 was observed for both species as early as 24 h post exposure to L1 larvae. The moult from L2 to L3 was initiated within 2 days post exposure and completed by 6-7 days post exposure. Some parasite-induced tissue damage occurred in the copepod but no cellular response against larval philometrids was observed.
Flounder, Paralichthys orbignyanus (Valenciennes), were captured in polluted and non-polluted sites within the Patos Lagoon Estuary, southern Brazil, over four seasons. Blood films showed a high prevalence of infection with a haemogregarine, or mixed parasitaemias of this and an organism resembling Haemohormidium terraenovae So, 1972. Haemogregarine gamont stages conformed to existing descriptions of Desseria platessae (Lebailly, 1904) Siddall, 1995 from flatfishes, but intraerythrocytic division of meronts was observed, leading to the recommendation for nomenclatural correction, placing the haemogregarine in the genus Haemogregarina (sensu lato) Danilewsky, 1885. Statistical analyses suggested that although sample sizes were small, infections with meront stages, immature and mature gamonts were all influenced by site, and possibly therefore, by pollution. Season also appeared to determine likelihood of infection with meronts and immature gamonts, but not mature gamonts, while adult fish gender apparently affected infection with immature and mature gamonts, but not meronts. The H. terraenovae-like organism exhibited unusual extracellular forms and did not match closely with the type description of H. terraenovae; precise identification was therefore difficult. Data analyses suggested that parasitism by this organism was influenced by site and fish gender, since females and males from non-polluted water were infected, but only females from the polluted site. Season was also important and significantly more adult fish of both sexes were infected with this parasite in the Brazilian summer and autumn, compared with winter and spring. Finally, these appeared to be the first observations of Haemogregarina platessae, and possibly H. terraenovae, from the southern hemispher.
- MeSH
- Coccidia klasifikace ultrastruktura MeSH
- kokcidióza epidemiologie veterinární MeSH
- látky znečišťující vodu MeSH
- nemoci ryb epidemiologie parazitologie MeSH
- parazitemie epidemiologie parazitologie veterinární MeSH
- platýs parazitologie MeSH
- prevalence MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Geografické názvy
- Brazílie MeSH
- MeSH
- barvení a značení metody MeSH
- cholinergní látky chemie MeSH
- finanční podpora výzkumu jako téma MeSH
- mikroskopie elektronová rastrovací MeSH
- platýs parazitologie MeSH
- ploštěnci anatomie a histologie růst a vývoj ultrastruktura MeSH
- stadia vývoje MeSH
- žábry parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
Results of a study on trypanorhynch cestodes of fishes from Indonesian coastal waters are presented. A new species, Dasyrhynchus thomasi sp. n., is described, and five species are recorded which all represent new locality records: Tentacularia coryphaenae Bosc, 1797; Nybelinia africana Dollfus, 1960; Nybelinia scoliodoni (Vijayalakshmi, Vijayalakshmi et Gangadharam, 1996); Sphyriocephalus dollfusi Bussieras et Aldrin, 1968; and Otobothrium penetrans Linton, 1907. Their known ranges of distribution are extended to the East-Indian Ocean. Scanning and transmission electron microscopy was used to clarify details of the tentacular armature and surface morphology of T. coryphaenae, D. thomasi and O. penetrans. In T. coryphaenae, hook-like microtriches along the bothridial tegument are embedded in the distal cytoplasm, sometimes showing a split base. The solid tentacular hooks are embedded into a fibrillar, highly ordered tentacular wall. D. thomasi is distinguished by its characteristically shaped bothridia and a triple chainette with winged hooks on the external surface of the tentacle. Tufts of microtriches with ciliated sensory receptors are regularly arranged on the bothridial surface of O. penetrans. They show similarities to sensory receptors reported from other trypanorhynch cestodes. Otobothrium pephrikos Dollfus, 1969 is considered a junior synonym for O. penetrans, and the variability of the scolex within trypanorhynch cestodes is emphasised.
- MeSH
- Cestoda klasifikace ultrastruktura MeSH
- cestodózy parazitologie veterinární MeSH
- elektronová mikroskopie MeSH
- nemoci ryb parazitologie MeSH
- oceány a moře MeSH
- platýsi parazitologie MeSH
- ryby parazitologie MeSH
- žraloci parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Indonésie MeSH
- oceány a moře MeSH
