Feeding pattern and size at first maturity (Lm50) of the exotic African catfish Clarias gariepinus (Clariidae) in Lake Naivasha, Kenya

Abstract

The African Catfish Clarias gariepinus (Burchell, 1822) is distributed widely in Africa ranging from the Nile River Basin to West Africa and Algeria in the North (Solak & Akyurt, 2001).The African catfish is also generally considered to be one of the most successful fish species in tropical aquaculture due to their faster growth (Nyamweya, Mlewa, Ngugi, & Kaunda-Arara, 2010). Clarias gariepinus is an exotic fish species in Lake Naivasha and was observed for the first time by Kenya Marine Fisheries Research Institute (KMFRI) in 2012, during regular fish stock assessment (Keyombe, Waithaka, & Obegi, 2015). The incidental introduction of catfish in the lake could probably has come through the inflowing rivers; Malewa, Gilgil and Karati into the lake. As catfish is non-native to the Lake, its ecological consequences on the fish assemblage and other biota are not known. Fish biology-based studies are, therefore, necessary for understanding the trophic relationships of the fish and for sustainable utilization of the fishery resources as well.