Effect of Different Water Sources on Egg Hatching Rate and Larval Survival of African Catfish in Borno State

Water source and quality are critical determinants of egg hatching success and larval survival in African catfish hatcheries, a concern of particular relevance in water-scarce environments such as Borno State, North East Nigeria. This study evaluates the effect of three water sources, namely borehole water, surface river water, and treated municipal tap water, on the fertilisation rate, hatching rate, and 14-day larval survival of Clarias gariepinus at a small-scale hatchery in Maiduguri. Water quality parameters were characterised for each source prior to the experiment. Artificial fertilisation was performed using milt from three males and eggs from two females, and fertilised eggs were incubated in separate 20-litre aquaria supplied with each water source type at identical flow rates. Fertilisation rate, hatching rate at 22 hours, yolk sac absorption time, and 14-day larval survival were recorded. Results showed that hatching rate was highest in borehole water (86.3%), followed by treated tap water (82.7%) and river water (74.1%). Larval survival at 14 days was significantly lower in river water treatments, attributed to elevated turbidity and coliform counts reducing feeding efficiency and increasing pathogen exposure. Yolk sac absorption was faster in borehole water. The study recommends borehole water as the preferred source for catfish hatchery operations in Maiduguri, providing practical guidance for hatchery operators seeking to optimise larval production under the water supply constraints characteristic of North East Nigeria.

Keywords: Clarias gariepinus, hatching rate, larval survival, water source, Borno State