Gut Contents, Feeding Ecology and Condition Factor of Sarotherodon melanotheron inhabiting Lagos Lagoon, Nigeria

Abstract

The gut contents, condition factor, food and feeding habit of Sarotherodon melanotheron in Lagos lagoon, Lagos State Nigeria were investigated. The specimens were collected by artisanal fishermen and were transported in icechest to the laboratory. The guts were carefully taken out to extract the stomach and preserved in 4% formalin for investigation of food items. Frequency of occurrence and numerical abundance methods were employed in this study. The calculated condition factor was 2.11. The result revealed that 3.75% of the sampled fish had empty stomach while 12.5%, 16.25%, 62.50% and 5.00% of the fish had 25%, 50%, 75% and 100% filled stomach
respectively. The result showed that S. melanotheron fed mainly on Synedra, Coscinodiscus, Mougeotia, Oscillatoria, Gyrosigma and Spirulina. Other food items include Zygnema, Pinnularia, Closterium, Melosira, Copepods, Penium, Cosmarium, Crustacean Parts, Microspora, Fish Scale, Rhizosolenia, Tabellaria, Crustacean Appendages and Spirogyra. The analysis showed the presence of food items of both plant and animal origin indicating that S. melanotheron is omnivorous. This study also revealed that the species was ‘very fat’ since food was abundant in the lagoon. Thus, regular monitoring and management of the lagoon is recommended.