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Registros recuperados: 15 | |
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Barbini,Santiago A.; Lucifora,Luis O.. |
ABSTRACT The eyespot skate, Atlantoraja cyclophora, is an endemic species from the southwestern Atlantic, occurring from Rio de Janeiro, Brazil, to northern Patagonia, Argentina. The feeding habits of this species, from off Uruguay and north Argentina, were evaluated using a multiple hypothesis modelling approach. In general, the diet was composed mainly of decapod crustaceans, followed by teleost fishes. Molluscs, mysidaceans, amphipods, isopods, lancelets and elasmobranchs were consumed in lower proportion. The consumption of shrimps drecreased with increasing body size of A. cyclophora. On the other hand, the consumption of teleosts increased with body size. Mature individuals preyed more heavily on crabs than immature individuals. Teleosts were... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chondrichthyes; Ontogenetic shifts; Predation; Southwest Atlantic. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000300214 |
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Pinhal,Danillo; Gadig,Otto BF; Wasko,Adriane P; Oliveira,Claudio; Ron,Ernesto; Foresti,Fausto; Martins,Cesar. |
Sharks are suffering from intensive exploitation by worldwide fisheries leading to a severe decline in several populations in the last decades. The lack of biological data on a species-specific basis, associated with a k-strategist life history make it difficult to correctly manage and conserve these animals. The aim of the present study was to develop a DNA-based procedure to discriminate shark species by means of a rapid, low cost and easily applicable PCR analysis based on 5S rDNA repeat units amplification, in order to contribute conservation management of these animals. The generated agarose electrophoresis band patterns allowed to unequivocally distinguish eight shark species. The data showed for the first time that a simple PCR is able to... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chondrichthyes; PCR; Species identification; 5S rDNA; Sharks. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200033 |
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Roman,Jorge M.; Chierichetti,Melisa A.; Barbini,Santiago A.; Scenna,Lorena B.. |
ABSTRACT The feeding habits of Callorhinchus callorynchus were investigated in coastal waters off northern Argentina. The effect of body size, seasons and regions was evaluated on female diet composition using a multiple-hypothesis modelling approach. Callorhinchus callorynchus fed mainly on bivalves (55.61% PSIRI), followed by brachyuran crabs (10.62% PSIRI) and isopods (10.13% PSIRI). Callorhinchus callorynchus females showed changes in the diet composition with increasing body size and also between seasons and regions. Further, this species is able to consume larger bivalves as it grows. Trophic level was 3.15, characterizing it as a secondary consumer. We conclude that C. callorynchus showed a behavior of crushing hard prey, mainly on bivalves,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chondrichthyes; Diet; Ontogenetic shifts; Southwest Atlantic; Trophic level. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000100202 |
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Díaz-Andrade,María Constanza; Lopez-Cazorla,Andrea; Galíndez,Elena Juana. |
Chondrichthyes constitute a conserve and vulnerable clade of increasing importance. However, there is scarce knowledge about the morphological aspects of the reproduction, so that only one work exists about the structure of the gravid uterus of an oviparous species. The work presented here describes the morphological, histological and histochemical remarks of the uterus of two Rajids of the Sympterygia genus along the life cycle. Both species presented paired uteri that lead independently to a common urogenital sinus. The uteri of immature females are filiform, translucent and unspecialized tubes. When sexual development starts, all the genital system displays a transitional and progressive change. In all studied females, independently of the maturing... |
Tipo: Journal article |
Palavras-chave: Chondrichthyes; Rajidae; Uterus; Sympterygia. |
Ano: 2013 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022013000300014 |
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Milessi,Andrés; Vögler,Rodolfo; Bazzino,Gastón. |
Hasta el presente no existía una correcta identificación de las especies de Squatina (Dumeril, 1806) en aguas Uruguayas de la Zona Común de Pesca Argentino-Uruguaya (ZCPAU). En dos cruceros de investigación realizados a bordo del B/I "Aldebarán" en octubre de 1995 y abril de 1996, a través de 143 lances efectuados entre 8 y 125 m de profundidad, se registró la presencia de S. guggenheim y de S. argentina, y se identificó por primera vez a S. occulta dentro de la ZCPAU. La separación de las especies se realizó según los criterios establecidos por <A HREF="#Vooren">Vooren & Da Silva (1991)</A> a través de la utilización de los siguientes caracteres morfológicos externos: presencia o ausencia de una fila medio-dorsal de espinas; forma y... |
Tipo: Journal article |
Palavras-chave: Chondrichthyes; Squatina; Zona Común de Pesca Argentino-Uruguaya. |
Ano: 2001 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382001000200008 |
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SOTO,J. M. R.. |
The presence of the sea leech, Stibarobdella macrothela (Schmarda, 1861) (Hirudinea, Piscicolidae), is marked in the south coast of Brazil, based on the single specimen with 67 mm (CT), collected in the intergill ventral region of a whaler shark, Carcharhinus brachyurus (Günther, 1870) (Chondrichtyes, Carcharhinidae), adult male with about 2 m (CT), being treated of the first registrations of S. macrothela in the Southwest Atlantic and the parasitic association with C. brachyurus. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Stibarobdella macrothela; Carcharhinus brachyurus; Hirudinea; Chondrichthyes; Ectoparasitism. |
Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082000000400024 |
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Martin, Corinne; Vaz, Sandrine; Ellis, J. R.; Lauria, Valentina; Coppin, Franck; Carpentier, Andre. |
Generalised Linear Models, combined with a Geographic Information System, were used to map the habitats of ten demersal elasmobranch taxa (five skates, four sharks and a stingray) in the eastern English Channel, based on an annual fishery-independent bottom trawl survey conducted each October, and covering 21 years. Habitat models showing mean density levels were developed for the most frequently occurring species, whilst binomial occurrence habitat models were built for less frequent species. The main predictors of elasmobranch habitats in the eastern English Channel were depth, bed shear stress and salinity, followed by seabed sediment type and temperature. Habitat maps highlighted contrasting habitat utilisation across species. Raja clavata, and to a... |
Tipo: Text |
Palavras-chave: Channel Ground Fish Survey; Chondrichthyes; Elasmobranchii; GLM; Grande Ouverture Verticale; Trawl survey. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00086/19730/17478.pdf |
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Muriana,C. B; Vasconcelos,B. V; Leandro,R. M; Malavasi,C. E; Amorim,A. F; Rici,R. E. G; Maria,D. A; Miglino,M. A; Ferreira,A.O. |
The hammerhead sharks shows a head laterally expanded with eyes and nostrils on the edges, which gives the species a hammer appearance. Another strand of studies indicates that the hypothesis of head shape alterations for better adaptions in the sensorial system with the development of structures associated to binocular sight and others sensorial organs. Given the variety of characteristics, the study aim was to describe the anatomical constitution of the hammerhead shark eye bulb. The bulb and its annexes exenteration was performed, and further dissection; the morphological description of the muscle insertions and eye bulb components were based on direct observation and were further photographed and catalogued. The eye bulb fragments and its annexes were... |
Tipo: Journal article |
Palavras-chave: Cartilaginous fish; Chondrichthyes; Vision; Microscopy; Morphology. |
Ano: 2017 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022017000100045 |
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Follesa, Maria C.; Marongiu, Martina F.; Zupa, Walter; Bellodi, Andrea; Cau, Alessandro; Cannas, Rita; Colloca, Francesco; Djurovic, Mirko; Isajlovic, Igor; Jadaud, Angelique; Manfredi, Chiara; Mulas, Antonello; Peristeraki, Panagiota; Porcu, Cristina; Ramirez-amaro, Sergio; Salmeron Jimenez, Francisca; Serena, Fabrizio; Sion, Letizia; Thasitis, Ioannis; Cau, Angelo; Carbonara, Pierluigi. |
Thanks to the availability of the MEDITS survey data, a standardized picture of the occurrence and abundance of demersal Chondrichthyes in the northern Mediterranean has been obtained. During the spring-summer period between 2012 and 2015, 41 Chondrichthyes, including 18 sharks (5 orders and 11 families). 22 batoids (3 orders and 4 families) and 1 chimaera, were detected from several geographical sub-areas (GSAs) established by the General Fisheries Commission for the Mediterranean. Batoids had a preferential distribution on the continental shelf (10-200 m depth). while shark species were more frequent on the slope (200-800 m depth). Only three species, the Carcharhiniformes Galeus melastomus and Scyliorhinus canicida and the Torpediniformes Torpedo... |
Tipo: Text |
Palavras-chave: Fish; Chondrichthyes; Bottom trawl surveys; Distribution; Abundance; Mediterranean. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00600/71220/69591.pdf |
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Johanson, Zerina. |
Various fossil lungfish taxa preserve distinct depressions on the smooth postbranchial lamina of the dermal pectoral girdle. These depressions are largely unknown in other sarcopterygian fishes, but are present in the rhizodont sarcopterygian Strepsodus. Comparisons with extant actinopterygian fishes suggest these depressions mark the point of origin for the clavobranchialis musculature, extending anterodorsally into the gill chamber to insert on the ventral surface of the ceratobranchial(s). Studios examining feeding and respiratory mechanisms of bony fishes (Osteichthyes) have emphasised the role of mandibular depression in generating negative pressures within the oral cavity to draw in water/air/food via suction. However, phylogenetically basal... |
Tipo: Article / Letter to the editor |
Palavras-chave: Clavobranchiales; Sarcopterygii; Actinopterygii; Chondrichthyes; Coracobranchiales; Dipnoi. |
Ano: 2003 |
URL: http://www.repository.naturalis.nl/record/534410 |
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Registros recuperados: 15 | |
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