Consulta: subjectFacets:"Elasmobranchs"
Registros recuperados: 10
Data/hora: 01/06/2024 10:24:34

Chromosomal characterization of Amazonian freshwater stingrays with evidence for new karyomorphs and XX/XY sex chromosomes
Provedor de dados: 74
Autores: Valentim,Francisco Carlos de Souza; Porto,Jorge Ivan Rebelo; Feldberg,Eliana.
Abstract Cytogenetic studies in the subfamily Potamotrygoninae have provided valuable insights into the understanding of the evolution and diversification of its species. In the present study, the chromosomal features of seven nominal potamotrygonin species are provided: Plesiotrygon iwamae (2n=74, FN=120), Potamotrygon amazona (2n=66, FN=107), P. constellata (2n=66, FN=110), P. leopoldi (2n=64, FN=102), P. motoro (2n=66, FN=106) from four different localities, and P. orbignyi (2n=66, FN=106), P. scobina (2n=66, FN=104), from Central Amazon. Additionally, we found a new karyomorph in P. wallacei. We considered the localization of Nucleolus Organizer Regions (NORs), as well as the pattern of constitutive heterochromatin, as species-specific characters. We...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Elasmobranchs; Cytogenetics; Chromosomal rearrangements; Sex chromosomes; Karyotypic diversity.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572019000400578

Using acoustic telemetry to estimate post-release survival of undulate ray Raja undulata (Rajidae) in northeast Altantic
Provedor de dados: 5
Autores: Morfin, Marie; Simon, Julien; Morandeau, Fabien; Baulier, Loic; Méhault, Sonia; Kopp, Dorothee.
The landing obligation introduced in the reform of the European Union Common Fisheries Policy requires landing all catches of species under quota. However, exemptions may be granted for species for which “scientific evidence demonstrates high survival rates”. Captivity experiments are often used to determine fish survival rates, but they are difficult to perform for large species such as rays due to the limited storage capacity of tanks. Thus, little information is available on ray survival after release despite an identified potential for high survival. We used acoustic telemetry to study rays discarded from a coastal bottom trawl fishery in their natural environment and present a new ad hoc approach to derive a minimum survival rate. After capture under...
Tipo: Text
Palavras-chave: Tagging; Discard survival; Trawl fishery; Elasmobranchs; Bay of Biscay.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00503/61432/65312.pdf

Ovarian Folliculogenesis in the Smallnose Fanskate Sympterygia bonapartii (Müller &amp;amp; Henle, 1841) (Chondrichthyes, Rajidae)
Provedor de dados: 77
Autores: Díaz-Andrade,M. C; Galíndez,E. J; López-Cazorla,A; Estecondo,S.
Chondrichthyes have become an important economic resource in the last decades, with Argentina as one of the countries that exploits more sharks and skates, even at levels that exceed de limits of many species. However, there is a scarce knowledge of the reproductive biology of this group, particularly from species inhabiting the Southern hemisphere. This work shows the most relevant facts during folliculogenesis in Sympterygia bonapartii. Results show that germinal cells are present in immature and maturing females. The most important facts that vary along de follicular development are the number of types and layers of follicular cells, the establishment of thin projections from the follicular cells and the degree of development of the thecae. Follicular...
Tipo: Journal article
Palavras-chave: Elasmobranchs; Reproduction; Ovary; Folliculogenesis; Sympterygia bonapartii.
Ano: 2011
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022011000100030

The Female Reproductive System of Zearaja chilensis (Guichenot, 1848) (Chondrichthyes, Rajidae): Gametogenesis and Microscopic Validation of Maturity Criteria
Provedor de dados: 77
Autores: Wehitt,Anahí; Di Giacomo,Edgardo E; Galíndez,Elena J.
Chondrichthyans are extremely susceptible to overfishing due, among other things, to their reproductive adaptations. Basic knowledge of reproductive parameters is essential, both of ecological and for economic points of view. Zearaja chilensis is a valuable economic resource in South America. This work analyzes the microanatomy of female reproductive system, as well as the size of the onset of vitellogenesis. The material was fixed in Bouin and processed using routine histological techniques. Both ovaries are equally functional. Folliculogenesis depicts the same pattern of other Chondrichthyans. Follicles with different degrees of maturation coexist in mature animals, with the exception of oogonia, which were only found in immature individuals. Likewise,...
Tipo: Journal article
Palavras-chave: Elasmobranchs; Reproductive system; Ovary; Zearaja chilensis.
Ano: 2015
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022015000100049

Morphological Changes in the Pregnant Uterus of the Smooth Hound Dogfish Mustelus schmitti Springer, 1939 (Gatuzo) (Condrichthyes, Triakidae): Microscopic Study and Phylogenetic Reproductive Implications
Provedor de dados: 77
Autores: Galíndez,E. J; Díaz Andrade,M. C; Moya,A. C; Estecondo,S.
Elasmobranchs are important, not only as an economic resource but also for their phylogenetic position. Their slow growth and long reproductive cycles, together with the high fisheries pressure exerted, attempt to the knowledge of all biological parameters of species. In this work we analyze the histology of the pregnant uterus of the gatuzo, a viviparous aplacental shark. The mucosa depicts modifications similar to those of placental species and others proper of histotrophism. Likewise, a network-like muscular layer in the mucosa was described for first time in the genus. The presence of vitelline plates in the gut of at term embryos suggests that the maternal supplies are not enough for the big fetus development. The relationships between maternal...
Tipo: Journal article
Palavras-chave: Elasmobranchs; Reproduction; Uterus; Viviparity; Mustelus schmitti.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022010000400004

Use of Pristis spp. (Elasmobranchii: Pristidae) by Hunter-Gatherers on the Coast of São Paulo, Brazil
Provedor de dados: 83
Autores: Gonzalez,Manoel M. B.
Artifacts made from rays (rostral teeth and spine) are very common in shell mounds on the coast of São Paulo, Brazil. The presence of the genus Pristis among the studied species of elasmobranch fishes in this shell mounds reinforces the hypothesis these animals occurred in southeastern Brazil, and were used by hunter-gatherers. I analyzed twelve rostral teeth of the genus Pristis from shell mounds. The teeth have artificial marks left from making arrows and harpoons. The basic function of the teeth found in these shell mounds was the production of tools and ornaments. From the analyzed teeth, ten (83%) were associated to the faunal remain and two (17%) were associated with burials, and they can be considered as ceremonial or votive elements. There had been...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sawfish; Elasmobranchs; Shell mounds; Zooarchaeology; Human ecology.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252005000300010

Reproductive biology of the eyespot skate Atlantoraja cyclophora (Elasmobranchii: Arhynchobatidae) an endemic species of the Southwestern Atlantic Ocean (34ºS - 42ºS)
Provedor de dados: 83
Autores: Wehitt,Anahí; Colonello,Jorge H.; Macchi,Gustavo J.; Galíndez,Elena J.
ABSTRACT Atlantoraja cyclophora is an endemic skate to the continental shelf of the Southwestern Atlantic Ocean (22ºS-47ºS) and a by-catch species in commercial bottom trawl fisheries. The morphometric relationships, the size at maturity and the reproductive cycle of this species were analyzed, with samples collected between 34ºS and 42ºS. The size range was 190 to 674 mm total length (TL) for males and 135 to 709 mm TL for females. Sexual dimorphism between the relationships TL - disc width and TL - total weight was found, with females wider and heavier than males. The mean size at maturity for males was estimated in 530 mm TL and for females in 570 mm TL. The gonadosomatic index (GSI) in mature females varied seasonally and showed the highest value in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Arhynchobatidae; Dimorphism; Elasmobranchs; Maturity; Reproduction.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252018000200207

Morphological analysis and description of the ovaries of female silky sharks, Carcharhinus falciformis (Müller &amp;amp; Henle, 1839)
Provedor de dados: 83
Autores: Rêgo,Mariana G.; Hazin,Fábio H. V.; Evêncio Neto,Joaquim; Oliveira,P. G. V.; Soares,Maria Goretti; Torres,Keilla Regina L. S.; Lana,Fernanda O.; Roque,Pollyana C. G.; Santos,Natália L.; Coelho,Rui.
This work aims to study the female reproductive tract of silky sharks, Carcharhinus falciformis, captured in the South and Equatorial Atlantic Ocean. Samples were collected between January 2008 and March 2010 through oceanic commercial vessels that targeted tuna and swordfish, with a total of 17 females collected. The methodologies followed for analyzing the ovaries of those females included both macroscopic and histological analysis. Macroscopically, it was possible to determine that the ovaries on these sharks is suspended by mesenteries in the anterior section of the body cavity, heavily irrigated by blood vessels, and contains a wide range of oocytes. Ovaries were found in three distinct maturational stages: Stage I (Immature), Stage II (Maturing) and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Elasmobranchs; Histology; Maturity; Ovary; Reproduction.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000400815

Hifalomicose em Mustelus schmitti (Springer) (Chondrichthyes, Triakidae)
Provedor de dados: 104
Autores: Gonzalez,Manoel Mateus Bueno.
Both fungai and algal infections have been reported in elasmobranchs. This study describes the first record of hyphalomycosis infection in Mustelus schmitii (Springer, 1940). The data was obtained through the examination of one animal in captivity and ninety five in their natural environment. Was also detected four cases of Fusarium solani infection. The impact of these diseases on the wild population is unknown.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hyphalomycosis; Elasmobranchs; Mustelus schmitii; Brazil.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751999000200002

Morphological abnormality in a Longnose Stingray Hypanus guttatus (Bloch &amp;amp; Schneider, 1801) (Myliobatiformes: Dasyatidae)
Provedor de dados: 49
Autores: Schmid,Kurt; Andrade,Marcelo; Machado,Fabiola; Araujo,Juliana; Corrêa,Eglé; Giarrizzo,Tommaso.
Abstract: A Longnose stingray Hypanus guttatus (Bloch &amp; Schneider, 1801) embryo with a major asymmetrical morphological abnormality to its pectoral fin was obtained from commercial shrimp fisher's bycatch, off the coast of the Amazon River Mouth in northern Brazil. The specimen and the deformity, which would presumably have impeded its long-term survival, are described and documented in detail. We herein provide the first report of an abnormal individual of this species for the Brazilian coast.
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Fish; Elasmobranchs; Atlantic; Teratology; Deformity.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032019000400502