The interactive effect of water temperature and salinity on yolk absorption rate, growth and larval survival of African catfish Clarias gariepinus (Burchell 1822)

The study was undertaken to determine the interactive effect of water temperature and salinity on yolk absorption rate, growth and survival of C. gariepinus larvae. Fertilized eggs, from broodstock reared for commercial seed production were incubated in 1000ml glass flasks and received one of the nine temperature (25, 28, and 31°C) and salinity (0, 3 and 6ppt) combinations in triplicates. The experiment was kept viable until all the yolk was fully disorbed. Data collected included yolk absorption rate and period, average rate of growth in length and larval survival of C. gariepinus, while water temperature was monitored periodically. The results showed that: Both temperature and salinity and their interaction had a significant effect on yolk absorption rate and period, average rate of growth in length and larval survival of C. gariepinus. A temperature and salinity combination of 28-31°C and 0ppt was found to be suitable for nursing C. gariepinus larvae. This is evidenced by having the least yolk absorption rate and period, highest rate of growth in length and highest survival of C. gariepinus larvae. Hence this temperature-salinity combination is recommended for the improvement of catfish seed production which is a major problem in catfish industry.