Assessment of stomach contents of Oreochromis niloticus from the Lagos Lagoon, Nigeria

Abstract

Fish sustainability in an aquatic environment involves continuous and judicious management towards optimum production of resources, for rational utilization and availability for future generation. Stomach composition of Oreochromis niloticus collected from a tropical brackish water environment was investigated to assess food availability towards optimum fish productivity for rational public utilization. Oreochromis niloticus, a fish of high economic importance and a generalize omnivore endemic to fresh and brackish water of Sub-Saharan Africa, and Asia, was reviewed to know the food availability status of the Lagos Lagoon, Nigeria. The conditions of stomach contents of O. niloticus samples collected were visually determined and subjected to frequency of occurrence, dominance, numerical, volumetric and relative index methods. Analytical and descriptive statistics were used to show occurrence, prevalence and availability of food organisms, within Lagos Lagoon. Results of the investigation revealed the presence of phytoplankton, dinoflagellates, sand grains, insect parts, plants parts, fish parts and unidentified constituents in O. niloticus stomach contents. O. niloticus revealed herbivorous feeding habit and Bacillariophyceae food item with highest occurrence. Food items satisfy requirements for optimum sustainability. Key words: Stomach contents, tropical, Oreochromis niloticus, Lagos Lagoon, Nigeria.