Sex Ratio and Spawning Season of Blue Swimming Crab (Portunus pelagicus, Linnaeus, 1758) in North Java Sea, Indonesia

Abstrak

High value economy of blue swimming crab (Portunus pelagicus) increases its capture in nature done continuously without regard to biological phases, so that it might overfishing occurrence. This study aimed to analyze the sex ratio and spawning season of blue swimming crab (Portunus pelagicus) in the North Java Sea of Indonesia. The research sampling was collected during October 2016 to September 2017. The total sample obtained was 424 males and 790 females of blue swimming crab. The sex ratio of P. pelagicus was 1:1.86 (males: females) where the amount of female was higher than male, the result of chi square test of ratio for overall samples of blue swimming crab (P. pelgicus) was significantly different from the expected 1:1 value. The spawning season occurred throughout the year, ovigerous females were every month except in July, and the highest percentage of ovigerous females was in February (30.2%).