Maturation and reproductive seasonality in bonefish, A1bula vUlpes, from the waters of the Florida Keys
1997; National Oceanic and Atmospheric Administration; Issue: 3 Linguagem: Inglês
ISSN
1937-4518
AutoresRoy E. Crabtree, Derke Snodgrass, Christopher W. Harnden,
Tópico(s)Fish Biology and Ecology Studies
ResumoWe examined 528 bone fish to estimate length and age at sexual maturity and to describe sea sonal patterns in gonadal development. These fish ranged from 21 to 702 mm fork length CFL) and were collected in South Florida waters from 1989 to 1995. Gonads of 437 bonefish were ex amined histologically, and gonado somatic indices (GSI) were calculated for 449 bonefish. Male bonefish reached 50% sexual maturity (the predicted size and age at which half the individuals are expected to be sexually mature) at 418 mm FL (95% confidence interval 393-443 mm) and an age of 3.6 years (95% confidence interval 3.3-3.9 years). Females reached 50% sexual maturity at 488 mm FL (95% confidence inter val 472-504 mm) and 4.2 years (95% confidence interval 3.9-4.6 years). Lengths and ages at 50% maturity for males and females were significantly different. The smallest sexually mature male was 425 mm FL, and the small est sexually mature female was 358 mm FL. The youngest sexually mature male was 3 years old. and the youngest sexually mature female was 2 years old. Gonadal activity was seasonal and peaked during November-May. Vitel logenic oocytes were present in ovaries in every month exceptAugust and Sep tember and were most abundant dur ing November-May. Median GSI's were greatest during November-May and least during July-September for both males and females. No fully hydrated ovaries or postovulatory follicles were found, therefore we could not estimate spawning periodicity or batch fecundi ties. Thtal fecundity ranged from 0.4 to 1.7 million oocytes and had a signifi cant positive relation to fish weight. The absence of fully hydrated ovaries and postovulatory follicles in the bone fish we sampled suggests that bonefish spawn outside the traditional shallow water «2 m) fishing grounds in the Florida Keys.
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