keywords: Catfish, condition factor (K), Length-weight relationship, structured-unstructured water
The effective management of any fishery requires considerable knowledge of population parameters such as length-weight relationship. This relationship is very important in fisheries biology because it allows estimation of average weight of the fish of a given length group. The study of length – weight relationship and condition factor of Catfish (Clarias gariepinus) fingerlings reared in structured and unstructured water (de – chlorinated tap water) was carried out in the Zoology Laboratory of Nasarawa State University Keffi. Structured water was obtained from Innovative Biotech Limited along Keffi – Abuja road while Unstructured water (de – chlorinated tap water) from the University environment. Length – weight measurements were taken using electronic weighing balance (KERRO Model number: BL 20001), measuring board and centimeter rule. The regression analysis of length – weight relationship of C. gariepinus fingerlings were b < 2.835 in structured water and b < 2.512 in unstructured water. The fish in the structured water grew better both in length and weight than those in the unstructured water. However, this result indicated that both structured and unstructured water exhibited negative allometric growth pattern. The values of correlation coefficient (r) were 0.848 in structured water and 0.816 in unstructured water indicating a strong positive relationship between length and weight. The mean value of condition factor (K) was 1.00 in structured water and 0.99 in unstructured water showing that the fish fared well during the period of investigation. There was no significant difference (P > 0.05) in the condition factor of C. gariepinus fingerlings reared in both treatments although; fish in the structured water had a better living environment than those in unstructured water.