Relative growth and sexual maturity in the marine crabs, Portunus (Portunus) sanguinolentus (Herbst) and Portunus (Portunus) pelagicus (Linnaeus) along the southwest coast of India

The relative growth of the secondary sexual characters like chela in male and abdomen in female of Portunus (Portunus) sanguinolentus and P. (P.) pelagicus was studied and the results presented. Morphological analysis revealed that transitions in the cheliped dimensions and abdominal widths of these crabs are related to prepubertal and postpubertal changes associated with gonadal development and onset of sexual maturity. The study indicated that the pubertal moult occurred in P. (P.) sanguinolentus and P. (P) pelagicus at a carapace width of 85-90 mm in males and 80-90 mm in females as evident from sudden increase in morphological characterisitics. The allometric relations between the set of characters studied suggested that the relationships were positive and significant.