COMPARATIVE EFFECTS OF VARYING STOCKING DENSITIES ON THE LENGTH-WEIGHT RELATIONSHIP AND MORPHOMETRICS OF HETEROCLARIAS
Afia, O. E.
1Department of Fisheries and Aquatic Environmental Management
University of Uyo, Uyo, Nigeria.
Email: ofonimeafia@uniuyo.edu.ng
ABSTRACT: Length-weight relationships and morphometrics are crucial indices for assessing the healthiness of a fish under varying stocking densities. Hybrid fingerlings of Clarias gariepinus x Heterobranchus longifilis were assessed for length-weight relationship and morphometric indices influenced by varying stocking densities for 12 months. Fifteen (15) improvised tarpaulin tanks measuring 1×1×1 m3 and filled with 250L of water were employed for this study. The study was designed to have five different stocking densities (SD), T1 = 100fish/m2, T2 = 75fish/m2, T3 = 38fish/m2, T4 = 18fish/m2 and T5 = 9fish/m2 as treatments and were in triplicates. The fish was fed three times daily (08:00, 13:00 and 18:00 hours) using commercial feed at 2.0% body weight. The feed was adjusted monthly with increase in body weight. The initial weight (2.06 ± 0.48 g) and total length (4.13 ± 0.25 cm) of the fingerlings were taken before stocking them in the various tanks which were randomly positioned. At the end of the study, T1 had the best growth function (2.91) which was closely followed by T2 (2.81). Condition factor was highest in T2 (1.04). There was significance (p<0.05) in morphometrics such as total weight, standard length, head length and dorsal fin length while total length and anal fin length were insignificant (p>0.05) across the different stocking densities. This study recommends 75-100 fish/m2 stocking densities and proper management of water quality parameters to obtain best growth for aquaculturists interested in raising hybrid catfish.
Keywords: length-weight relationship, morphometric parameters, condition factor, hybrid catfish, Heteroclarias, stocking densities
