Seasonal Reproductive Biology of the Bignose Fanskate Sympterygia acuta (Chondrichthyes, Rajidae)

摘要: 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 bonapartii, S. acuta has a cycle. To test this hypothesis, examined multiple lines evidence: (1) time appearance females carrying egg cases wild neonates; (2) in gonadosomatic index follicle diameter, as indicators activity; (3) egg-laying season, incubation time, fecundity captive individuals. A total 351 specimens were examined. Size at 50 % maturity was 475 478 mm length for males females, respectively. marked cycle observed. Both diameter adult increased from winter spring reached their lowest value during summer. Fecundity was, on average, 52 eggs per female laying season. Egg peaked between August December; hatched after 119–131 days. This schedule predicts neonates by January through April. Accordingly, young-of-the-year observed May. Unlike most other skates, southwest Atlantic species life shallow, waters, matching seasonality environment with activity hatching These shallow which important spp., threatened human impacts.