Stomach Content Analysis of Feed and Feeding Habit of Oreochromis Niloticus Fish Species in Baro-Akobo Basin, South West Ethiopia in Case of Alwero Dam

Abstract

The food and feeding habit of Oreochromis niloticus inhabiting Alwero dam water body was investigated. This study was carried out to identify the type and availability of food consumed by fish. Two hundred fifty fish were obtained from the reservoir during wet and dry season. Total length (TL; cm) and Total weight (TW; g) of each fish was measured. The fish body was dissected and the entire gut was removed. The stomachs were opened and its content was poured on a petridish and stirred with water drops. The food materials were identified visually and using microscope. The fish sizes ranged between 26.5 to 39cm (TL) and 390 – 1400g (TW). More than quarters of the fish caught in Alwero dam have (80.4%) full and (19.6%) empty stomach. The study reveals the importance of zooplankton (34%), fish remain (27), phytoplankton (22%), insect part and mud /sand (8%) form important items in the diet of this species. Size based differences were showed highly significance by shifting of their feeding behavior from eating zooplankton to phytoplankton as size increased and seasonal availability was additional factor for ontogenetic shift. Morphometric relationship of total weight and total length were showed a linear relationship indicating effect of length over weight and vice versa.

Keywords: Nile tilapia, Oreochromis niloticus, food and feeding, zooplankton, Alwero dam.

DOI: 10.7176/JBAH/11-3-01

Publication date: February 28^th 2021