Artículos de revistas
Seasonal Reproductive Biology of the Bignose Fanskate Sympterygia acuta (Chondrichthyes, Rajidae)
Fecha
2014-09Registro en:
Mabragaña, Ezequiel; Lucifora, Luis Omar; Corbo, Maria de Lourdes; Díaz de Astarloa, Juan Martín; Seasonal Reproductive Biology of the Bignose Fanskate Sympterygia acuta (Chondrichthyes, Rajidae); Springer; Estuaries and Coasts; 38; 5; 9-2014; 1466-1476
1559-2723
CONICET Digital
CONICET
Autor
Mabragaña, Ezequiel
Lucifora, Luis Omar
Corbo, Maria de Lourdes
Díaz de Astarloa, Juan Martín
Resumen
Most skates are adapted to shelf and slope environments experiencing less seasonal variation than coastal ecosystems. Here, we analyze the reproductive ecology of Sympterygia acuta. We hypothesize that, like its congener Sympterygia bonapartii, S. acuta has a seasonal reproductive cycle. To test this hypothesis, we examined multiple lines of evidence: (1) time of appearance of females carrying egg cases and wild neonates; (2) seasonal variation in gonadosomatic index and follicle diameter, as indicators of reproductive activity; and (3) egg-laying season, incubation time, and fecundity in captive individuals. A total of 351 specimens were examined. Size at 50 % maturity was 475 and 478 mm total length for males and females, respectively. A marked seasonal reproductive cycle was observed. Both gonadosomatic index and follicle diameter of wild adult females increased from winter to spring and reached their lowest value during summer. Fecundity was, on average, 52 eggs per female per laying season. Egg laying of captive females peaked between August and December; eggs hatched after 119–131 days. This schedule predicts the appearance of neonates in the wild by January through April. Accordingly, wild neonates and young-of-the-year were observed between January and May. Unlike most other skates, southwest Atlantic Sympterygia species are adapted to life in shallow, coastal waters, matching the seasonality of the coastal environment with egg-laying activity in spring and hatching in summer. These shallow coastal waters, which are important in the life cycle of Sympterygia spp., are threatened by human impacts.