Tamanho de primeira maturação, idade e crescimento de Micropogonias furnieri (Desmarest, 1823) na Baía de Ubatuba, SP

Abstract

The white croaker Micropogonias furnieri is an important fishery resource in coastal zones of Southeastern Brazil. In spite of several studies on the bio-ecological aspects of this species, the available information vary widely, suggesting deferent stocks or populations, thus it is necessary update information and revision on reproductive and growth parameters in different areas of species occurrence. This study is based on the white croaker stock exploited by the artisanal fisheries in Ubatuba bay, SP. We aimed to determine reproductive and growth parameters for this species and compared with available information, in order to contribute with conservation policies. We examined a total of 359 individuals (140 females and 219 males), with total length ranging from 200 to 800mm for females, and 200 to 470mm for males. They were collected weekly by gill nets (stretched mesh 10-12cm), between August 2010 and July 2011. Size at maturation (L50) was 315 and 320mm for males and females, respectively, which were slightly higher than the reported by the available literature in the region, and larger than to the minimum allowed capture size established by the Brazilian legislation (Lt = 25 cm). By readings of annual rings in sagittae otoliths sections it was obtained the parameters for the growth curve for females Lt = 60×(1–e-0.051t -2.11) and males Lt = 52.38×(1–e-0.053t -2.78). These results confirm the slow growth for this species in adult phase. Furthermore, although this species have a long reproductive period (March to December) only one ring is formed each year. For the first time was recorded the long longevity of this species (at least 26 years) for the Southeastern Region, favored by the use of otoliths when compared to scales.