Differences in physicochemical properties of water from neighbourhood boreholes and their usefulness in Clarias gariepinus egg hatching

Abstract

Water parameters and egg hatching success in water from three boreholes within close proximity were investigated. The studies were conducted to ascertain differences in their quality and ability to support Clarias gariepinus egg hatching. The boreholes were tagged 300m, 400m and 330m in relation to their distances from a perennial stream within the vicinity. Temperature and pH were investigated using digital metres. Dissolved oxygen, alkalinity and total hardness were determined using titration method. The water parameters were measured twice a week for 5 weeks. Percentage egg hatching, time to commencement and termination of egg hatching were studied in triplicates. The results obtained showed that pH, Dissolve oxygen (DO), Alkalinity and total hardness were significantly different (P<0.05) among the boreholes, while temperature was not significantly different (P>0.05). Total hardness fluctuated most at 21% coefficient of variation (CV). Egg fertilization success was not significantly different (P>0.05). Percentage egg hatching (68.8%, 92.8% and 87.3% for 300m, 400m and 330m) respectively was significantly different (P<0.05). Higher coefficient of variation in hardness enhanced egg hatching. It could be induced in hatchery operations. Time to commencement (1443, 1453 and 1517) minutes and termination of hatching (1962, 1957 and 2037) minutes were significantly different (P<0.05). Larval survival by day-3 post hatch was significant[y different (P<0.05). The study provided evidence of disparity in water quality among the boreholes and revealed differences in their ability to support Clarias gariepinus egg hatching. These suggest carefulness in choice of borehole water for fish egg hatching regardless of proximity of boreholes.

Keywords: Catfish, Propagation, Water and Egg