Stomach Content, Length-weight Relationship and Condition Factor of Tilapia spp. found in the Sombreiro River across Three Communities in Rivers State, Nigeria

Abstract

Aim: The present study aims to determine the condition factor incomplete of Tilapia guineensis and Sarotherodon melanotheron in Sombreiro River across Buguma, Abonnema and Degema communities in Rivers State. Study Design: This study employs fieldwork, laboratory experimental design, statistical analysis and interpretation of data. Place and Duration of Study: Live fish samples were caught by fishermen in Buguma, Abonnema and Degema communities in Kalabari kingdom of Rivers State, and were conveyed in a rectangular plastic aquarium containing ice blocks and oxygen bags to the department of Applied and Environmental Biology, Rivers State University. The duration of the study lasted for twelve weeks (65 days). Methodology: One hundred and eighty fish samples give their average weights and lengths were identified. The fish samples were weighed using an electronic weighing balance, the total length and length of intestine were measured with a meter rule (cm), color of fish, spines and rays of fish were also observed. Their stomach contents were analyzed viewing under a microscope. The frequency of occurrence method and the numerical method were used for analyzing the food items. Results: The stomach content analysis indicated that the major food was phytoplankton. The length and weight relationship in the three sampled stations for T. guineensis and Sarotherodon melanotheron showed negative allometric growth, (<3).  The condition factor for all the fish samples was greater than one. The physicochemical parameters showed that there were significant differences in the various physicochemical parameters across the study stations except for turbidity (P=0.744) and salinity (P=0.922), that showed no significant difference across the study stations. Conclusion: The length-weight relationship in fishes can be affected by a number of factors including season, habitat, gonad maturity, sex, diet, stomach fullness, health and differences in length ranges of the specimen caught. The exact relationship between length and weight differs among species of fish according to their inherited body shape, and within a species according to the condition (robustness) of individual fish. The stomach content analysis of the sampled fishes provided a baseline study of food and feeding habits of Tilapia species in the sampled stations.