ABSTRACT
A total of 448 stomachs were examined from Nile tilapia (Oreochromis niloticus) captured in the Nile River at Cairo, Egypt, taken from April 1978 to July 1979. The Nile tilapia is an omnivore with higher feeding preference for phytoplankton and plant detritus. Zooplankton was next in importance and zoobenthos were found in significant amounts in the diet. A few fish eggs and scales also were encountered, along with some mud. Based on stomach fullness trends, the fish showed highest feeding activity during the spring, whereas the lowest occurred during the winter. The fish also showed greater feeding activity as they grew. The food and feeding habits changed with increase in size and with the change in seasons as well as the availability of certain food items which have seasonal variation in the environment. There were also morphological differences between the young and the adult. As the young fish grows, the intestines lengthen and have more loops.
