Biologia reprodutiva do peixe-rei, Elagatis bipinnulata (Quoy &Gaimard, 1825), capturado na zona econÃmica exclusiva (ZEE) do nordeste do Brasil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The rainbow runner (Elagatis bipinnulata), belonging to the family Carangidae, is one of the most important families of tropical marine fish, with a high commercial and sport-fishing value. It has a circumtropical distribution, being found, in the Atlantic Ocean, from the north of Massachusetts-USA, to the southern limit of the northeast coast of Brazil. The study of the reproductive biology of the rainbow runner, including the reproductive cycle, type of spawning, and size at first sexual maturity, among others, is of fundamental importance to guarantee the sustainability of its explotation. The present work seeks to contribute information on the reproductive biology of the rainbow runner captured in the Archipelagos of Fernando de Noronha (AFN) and SÃo Pedro and SÃo Paulo (ASPSP). In AFN 95 gonads were analyzed (62 females and 33 males), during the period of April to November, 2001, while in ASPSP 352 individuals were analyzed (201 females and 151 males), from July 1999 to November 2003. The examined specimens had their zoological length (ZL) measured, being, then, eviscerated for the collection of the gonads. In the laboratory, the gonads had their length, width and weight measured and sex macroscopically identified. Through histological analysis, five different sexual maturation stages for females were identified: immature, maturing, mature, spent and resting. In ASPSP, most of the mature and maturing females were observed from January to May. The highest values of the gonadal index (GI), between 7,65 and 55,00 were also observed during this period. In AFN, mature and maturing females were more frequent from April to May. The highest values of GI were also observed during those months, varying from 5,98 to 30,16. The size at first sexual maturity (L50) for females in ASPSP was estimated as 55,7cm of ZL. The few data available on adult females sampled in Fernando de Noronha made it impossible to analyse its L50. For both studied areas, the species showed a total spawning, synchronous in two groups. The gonads of the males sampled had very similar histological characteristics, making it impossible to differentiate the sexual stages. A great dispersion was observed in the weight of male gonads making it also impossible to ascertain the size at first sexual maturity. As for females, the GI of males presented the highest values from January to May in ASPSP, and from April to May in AFN. These results suggest that the period of spawning of the species in these areas happens in the first semester of the year

ASSUNTO(S)

zona econÃmica exclusiva maturaÃÃo sexual biologia reprodutiva Ãndice gonadal oceanografia

ACESSO AO ARTIGO

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