The reproductive biology and cycle of Rioraja agassizi (Müller and Henle, 1841) (Chondrichthyes: Rajidae) in southeastern Brazil, SW Atlantic Ocean
Specimens of Rioraja agassizi were collected at Guarujá pier, São Paulo State, Brazil, from March 2005 to March 2006. A total of 275 males were captured. Based on the analysis of the clasper length, gonad weight, clasper gland length, alar thorns and lobule diameter, the size-at-maturity was estimat...
| Autores: | , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2007 |
| País: | Brasil |
| Institución: | Universidade Federal do Rio Grande (FURG) |
| Repositorio: | Repositório Institucional da FURG (RI FURG) |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.furg.br:1/1244 |
| Acceso en línea: | http://repositorio.furg.br/handle/1/1244 |
| Access Level: | acceso abierto |
| Palabra clave: | Clasper Clasper gland Vitellogenic follicles Elasmobranchs Nidamental gland Egg-bearing Gonads Elasmobranquios Glándula nidamentária Deposición de cápsulas ovígeras Gónadas |
| Sumario: | Specimens of Rioraja agassizi were collected at Guarujá pier, São Paulo State, Brazil, from March 2005 to March 2006. A total of 275 males were captured. Based on the analysis of the clasper length, gonad weight, clasper gland length, alar thorns and lobule diameter, the size-at-maturity was estimated to be 32 cm. There were 1049 females in the record. Size-at-maturity was calculated in 40 cm. Sexual resting females were observed. Gonadosomatic and hepatosomatic indexes varied significantly in both sexes throughout the year. However, ovulation, egg-laying and presence of sperm in the seminal vesicle were observed all year round. For this reason, an annual cycle with at least one peak in the sexual activity is proposed for this species. |
|---|