Food and feeding habits of African bony tongue, Heterotis niloticus from Urhie Lake, Igbide, Delta State, Nigeria.

Abstract

For efficient management in fish farming there is need for proper nutrition strategies, which can only be achieved by understanding the food and feeding habits of the fish to be cultured in their natural habitat. The study was conducted to investigate the food and feeding habits of Heterotis niloticus in Urhie Lake. Fish samples were collected from fishermen at the landing sites, the major fishing methods employed by the fishermen were cast and set netting. A total of 20 specimens (13 males and 7 females) of H. niloticus were collected examined to ascertain the food and feeding habits using frequency of occurrence, numerical and point methods. The stomach contents of the samples were studied by visual examination. Results revealed that the specimens had standard length ranging from 30.7cm to 54.7cm in males and 32.6cm to 43.6cm in females. Fish body weights varied from 230.0g to 1950g in males and between 400.0g and 740g in females. The condition factor ranged from 0.79-1.29 for males and 0.89-1.25 for females. Results of stomach contents showed that the fish fed mostly on macrophytes accounting for 43.16% followed by phytoplankton (27.89%). Other food items observed were sand (16.32%) and unidentified mass, likely detritus (12.63%). Hence H. niloticus from Urhie Lake is considered to be herbivorous in nature.