Crescimento e ciclo reprodutivo do pargo-rosa (Pagrus pagrus Linnaeus, 1758) na região do Cabo Frio, Rio de Janeiro
DOI:
https://doi.org/10.5380/rn.v11i1-2.85148Keywords:
Red porgy, Brazil, growth, reproduction, Pagms pagmsAbstract
We examined 644 specimens of red-porgy (Pagms pagms) ranging from 170 to 448 mm CT collected from artisanal landings in Rio de Janeiro state waters from 1993 to 1995. Among all specimens we have sexed, females ranged from 170 to 520 mm CT (n=475) and males ranged from 200 to 517 mm (n=169). Scales from 175 females and 89 males, within 2-11 years-old were used to estimate growth parameters throughout nonlinear estimation methods. Marginal increment analysis of specimens 3-4 years old suggested that a single annulus was formed each year, during May-June. Growth rings in scales coul be associated with gonadal development and post-spawning periods. The von Bertalanffy growth equation for females, males and both sexes for red porgy were: CT = 523,3(l-e°'123 (t+2 09)), CT = 371,6 (1-e'0'200 <t+3'14>) e CT = 5 2 8 ,8 (l-e'0'107 (t+2,78)), respectively. We estimated that 50 % of the females in the population had reached sexual maturity by 220-230 mm CT and 230-240 mm (males). Red-porgies are protogynous hermaphrodites. Adult females ocurred during spring-summer and a single spawning period from November to February was observed. Estimates of fecundity ranged from 7 to 518 thousands eggs from females ranging from 259 to 375 mm CT. Advanced staged eggs (>270 jxm) were more frequent from spring to early summer.