A Study of Length-Weight Relationship and Condition Factor of West African Blue Crab (Callinectes pallidus) from Ojo Creek, Lagos, Nigeria

Abstract

The length-weight relationships and condition factor of the West-African freshwater blue crab, Callinectes pallidus, was studied from Ojo creek, Lagos Nigeria for one year. The crabs were separated into males (124) and females (126). The length-weight relationship and condition factors of the crabs were determined. Growth parameters a and b of the length-weight relationship, (LWR) W = aL b , was 22.73 and 21.83 for males, females, respectively. The values of b estimated were 35.82 and 29.44 for males, females, respectively. The regression equation for the LWR are Log w = 35.82+22.73 for males, Log w = -29.44+21.83 for females in the population. The coefficient of determination of males, females and entire population were 0.366 and 0.359, respectively. The LWR was positive allometric for all crabs, the condition factor k for male k = 66.52, female is – 67.64 and for the entire population is k = 66.89. Results also show that there is a weak correlation (r2 = 0.60) between total body weight (BW)/carapace length (CL) of the crabs. The length-weight distribution pattern did not show remarkable differences between species, sexes, and populations. Significant difference (P > 0.01) in condition factors between the sexes.