Effects of water depth on digestive enzymes activities of Clarias gariepinus (Burchell, 1822) fingerlings

The effects of water depth on the digestive enzymes activities of Clarias gariepinus was investigated. Ten concrete tanks (50x150x100 cm capacity) were used; each tank was filled with water at different experimental water depths (25, 50, 75,100 and 125 cm) under static culture system. The activity of protease, lipase and amylase from the pancreas of Clarias gariepinus was determined. Digestive protease, lipase and amylase showed optimum activities at 125 cm water depth with amylase activity showing greater variation across treatments compared to the other two digestive enzymes. Water depth positively influenced the release of these enzymes for feed digestion to occur with lipase being the most influenced by water depth. In conclusion water depth affects digestive enzymes activities in Clarias gariepinus fingerlings and it is recommended that 125 cm water depth should be used in culturing Clarias gariepinus.Keywords: Amylase; Clarias gariepinus; lipase; protease; water depth.