Carapace width-weight relationships and condition factor of blue swimming crab, Portunus pelagicus Linnaeus, 1758 (Crustacea: Decapoda) in Lasongko Bay, Southeast Sulawesi, Indonesia

To date, studies of carapace width-weight relationships in blue swimming crab (Portunus pelagicus Linnaeus, 1758) have primarily focused on differences between males and females within a population, whereas studies of the condition factor of this species remain limited.The objective of this study is to assess the carapace width-weight relationships and the condition factor of juvenile and adult crabs throughout the season in Lasongko Bay, Southeast Sulawesi, Indonesia.Monthly samplings of crabs were conducted using gill nets from April 2013 until March 2014.Data were analyzed by sex (juvenile and adult) and season.Carapace width-weight relationships were expressed as power and linear equations.Parameter values of the equations and the growth coefficient were tested using ANCOVA and t-tests, respectively; the condition factor was analysed descriptively.Carapace width-weight relationships of male and female juveniles and adults as well as ovigerous females exhibited very strong and positive relationships and an ismoteric pattern of growth.The growth coefficient and condition factor in both sexes fluctuated throughout the study period.Monthly fluctuations in the condition factor of male and female crabs were within similar ranges.Temporal variation in the fluctuations and timing of peak values of b and the conditions factor of male and female crabs was likely related to the crab reproductive cycle, particularly peak spawning in Lasongko Bay.