Reproduction in Bagre marinus (Ariidae) off Pernambuco, northeastern Brazil

Throughout 1997, the catches of artisanal gillnetters working of the coast of northeastern Brazil were sampled monthly for Bagre marinus (Mitchill 1815). Significantly more females (n = 207) than males (n = 82) were caught, although there was no significant difference in their size compositions (21 - 47 cm fork length, FL). All males sampled (21-40 cm FL) had developed gonads and were classified as sexually mature. According to macroscopic and microscopic examination of their reproductive tract, females were separated into four reproductive stages (immature, maturing, mature, and resting). Size at 50% sexual maturity for females was estimated to be 33 cm FL. A positive linear relationship was detected between the size of mature females and their fecundity (between 11 and 32 oocytes). Clear reproductive progress indicated a spawning period between March and May. We conclude that further fishery-independent data are required to determine patterns of male abundances and distributions