EFFECTS OF WATER PHYSICOCHEMICAL VARIATIONS ON THE HATCHABILITY AND SURVIVAL OF Clarias gariepinus (BURCHELL, 1822) LARVAE

ABSTRACT

This study investigated the effects of physicochemical parameters of four different water sources on hatchability and survival of Clarias gariepinus larvae. The water sources used were: rain water (T1), borehole water (T2), river water (T3) and well water (T4). The study entailed artificial induced breeding of C. gariepinus using the aforementioned water sources as incubation and culture medium of the hatched larvae for 14 days. Vital water physicochemical parameters assessed were temperature, pH, dissolved oxygen and ammonia, conductivity and total hardness. Hatchability rate was estimated 24 hours after incubation whereas larval survival rate was determined at 14 days’ post hatching. Data from the experiment were subjected to one-way analysis of variance (ANOVA) at (P<0.05) significance level. At the end of the experiment, results obtained for water physicochemical parameters in the four water treatments for conductivity and total hardness were significantly different (P<0.05). Rain water (T1) recorded a low mean conductivity value of 24.3±0.88 μScm and low mean total hardness value of 3.33±0.3 mgl. Percentage hatchability in all treatments was relatively high with the highest mean value of 93.1±1.60 % obtained in T1. Larval survival rate at 14 days post hatching was comparatively above average with the highest mean value of 63.7±2.41 % recorded in T2 while T1 recorded the lowest mean value of 44.2±0.55 %. This study has shown that borehole water (T2) is the most suitable water source for hatching and survival of C. gariepinus larvae.

LEAD AUTHOR

AWOKE, J. S.

CORRESPONDING AUTHOR

• NWAKPA, J. N.
• OTI, E. E.