Length-weight Relationship and Condition Factor of Cichlids in Eniong and Lower Cross Rivers, Niger Delta, Nigeria

Abstract

Length-weight relationship and condition factor are essential parameters used in determination of growth and well-being of fish. The length-weight relationship and condition factor of eight species of cichlids were examined from a total of 358 cichlids belonging to fourteen species and seven genera. Sampling was between January and June, 2020 in Eniong River and lower Cross River in the Niger Delta from three stations: station one in Eniong river, station two at the confluence of Eniong and lower Cross River, and station three at the lower Cross River. The length and weight of each fish was measured to the nearest millimeter and gram, respectively. The length-weight relationship (LWR) and condition factor (K) of the species Coptodon dageti, Coptodon guineensis, Coptodon zilli, Chromidotilapia guntheri, Hemichromis elongatus, Oreochromis niloticus, Pelmatolapia mariae and Sarotherodon melanotheron were determined using standard methods. Total length of fish ranged from 12.9 ± 5.01 in H. elongatus to 20.7 ± 3.37cm in C. zilli. Total weight ranged from 24.8 ± 13.80 in H. elongatus to 146.4 ± 68.0 g in C. zilli. The exponent b ranged from 1.54 for H. elongatus to 3.34 in Pelmatolapia mariae. The coefficients of determination (r2) varied between H. elongatus (0.74) and O. niloticus (0.96). Fulton’s condition factor (K) ranged from 1.2 6 ± 0.50 (H. elongatus) to 1.89 ± 0.43 (O. niloticus). Length-weight relationship revealed negative allometry for six species and positive allometry for two species (O. niloticus and P. mariae). Cichlids in this study were observed to be in good condition, as the K values were greater than one.