Biologia reprodutiva do Cangulo-rei (Balistes vetula Linnaeus 1758) no litoral de Pernambuco, Brasil

Abstract

The species Balistes vetula (LINNAEUS 1758) has great commercial value and is of extreme importance for artisanal fishing of the coast of the state of Pernambuco. This study aimed to understand the biology of the species is essential for its conservation and for a better understanding of the dynamics of the reef ecosystems, providing subsidies for a better management of conservation for the species through data such as: sexual ratio, size first maturity (L50), season and type of spawning. A total of 202 specimens were analyzed, 139 (64.9%) females and 75 (31.1%) males, presenting a sexual ratio of 1 male: 1.8 females; when analyzed by month, showed significant differences in the months of february, april, july, august, september, october and november(P <0.05) through the x² test. The standard length (SL) of the males ranged from 13.5 to 33.2 cm (mean ± SD 24.9 ± 2.22) and weight (WT) between 111.51 and 1.262.00g (mean ± SD 661.08 ± 131.07). For females, the standard length (SL) ranged from 15.3 to 32.8 cm (mean ± SD 25.2 ± 1.97) and total weight (WT) between 144.51 and 1.117.00g (mean ± SD 631.73 ± 1.97). The most frequent length class for males was 17.7 ˫ 19.1 cm and for females 19.1 ˫ 20.5 cm. The estimated coefficient of the length-weight ratio was 2.216 and 2.119 for females and males, respectively. From the t-test we can affirm that both sexes present a growth of the negative allometric type (b <3), that is, the growth is proportionally greater than the weight gain. The first maturation size (L50) for females was estimated at 19.11 cm of standard length (SL), using n = 131 individuals. For males it was estimated at 17.91 cm CP using n = 68 individuals. Through the analysis of the number of females in the mature stage and the values of the gonadosomatic index, it was observed that spawning occurs throughout the year, with a period of greater intensity in the months of September to December with a peak in September. The mean fecundity was 385,741 oocytes ranging from a minimum of 230,660 oocytes, where the ovary weighed 33.15 g and the total length (LT) was 31.2 cm, with a maximum of 677,876 oocytes, where the ovary weighed 78.64 geo CT of the fish was 28.6 cm. When analyzing oocyte development, it was observed that B. vetula spawns through lots and synchronously, where the oocytes are eliminated in the spawning and some in smaller quantities are in the reserve stock, denominating a total and synchronous spawning in two groups.