Título
Caracterización del modo de reproducción del pez guitarra Rhinobatos productus Ayres, 1856, con base en el desarrollo y alimentación embrionaria
Characterization in the mode of reproduction of shovelnose guitarfish Rhinobatos productus, ayres 1856 based on the development and nourishment of embryos
Autor
Alfonsina Eugenia Romo Curiel
Colaborador
Oscar Sosa Nishizaki (Asesor de tesis)
Nivel de Acceso
Acceso Abierto
Materias
Resumen o descripción
Los elasmobranquios son un grupo de peces primitivos mandibulados que han evolucionado de manera interesante en sus modos de reproducción. La diversidad resulta de la complejidad estructural de los úteros y de la regulación funcional interna de las diferentes especies. El objetivo de este trabajo es determinar el tipo de alimentación de los embriones de Rhinobatos productus y por ende el modo de reproducción.
The elasmobranchs are the oldest group of jawed fishes which have evolved in many aspects, including the mode of reproduction. Their diversity depends completely on the structural complexity of the uteri and the internal functional regulation. The main objective of this work was to determine the type of feeding of the embryos of Rhinobatos productus and therefore the mode of reproduction, this is a contribution to the basic biology of the species. Samples were taken in different periods from May 2004 through June 2007 in the commercial fisheries of San Felipe, B.C. and Bah´ ıa de Kino, Son. A total of 650 females, 2,047 embryos and 484 uterine eggs were examined. The gestation period lasts 12 months, initiated in July of one year and ends with the birth of the young in late June of the next year. An embryonic diapause was observed from August to March, and in the three remaining months there was accelerated isometric growth in the embryos, as they increase in length the external yolk sac (EYS) was consumed in its totality. Embryo size at birth varied from 16 cm up to 19.2 cm, depending on the maternal size and on ova size ovulation. The histological analysis of the uterus structures of pregnant females suggested that no secretions was used for the embryo’s nourishment before its birth, though they do have a regulation in the content of liquids and salts that is utilized in osmoregulation. The uterus had longitudinal folds with basal crypts throughout its length. The standard percentage of the water content in fertilized eggs was 48.6 %, and 80.75 % in fully developed fetus, and the dry weight lost was 16.3 % during development. This results indicate that R. productus is a strict yolk-sac viviparous species with no maternal contribution of matter nutrients during embryo development.
Editor
CICESE
Fecha de publicación
2007
Tipo de publicación
Tesis de maestría
Recurso de información
Formato
application/pdf
Idioma
Español
Sugerencia de citación
Romo Curiel,A.E.2007.Caracterización del modo de reproducción del pez guitarra Rhinobatos productus Ayres, 1856, con base en el desarrollo y alimentación embrionaria.Tesis de Maestría en Ciencias. Centro de Investigación Científica y de Educación Superior de Ensenada, Baja California.57 pp.
Repositorio Orígen
Repositorio Institucional CICESE
Descargas
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