Diet composition and feeding habits of Oreochromis niloticus (Linnaeus, 1758) in Lake Shala, Ethiopia

Abstract

This work is the modification of the first author's Ph.D. dissertation.

Morphometric relations and diet compositions of Nile tilapia Oreochromis niloticus (Linn. 1758) in Lake Tana Gorgora gulf, Ethiopia

“…Stomach content analysis of the present study disclosed that, about 17.3% of the guts scrutinized were vacant while 82.7% were non empty. The observed trivial number of vacant stomachs may be ascribed to the relatively short period of time between capture and dissection; and least possibility of food loss through digestion and regurgitation (Engdaw, 2014;Wagaw et al, 2022). It might also be due to the resisting ability of phytoplankton and detritus for digestion.…”

“…Suitability to various culture techniques and its tolerance to numerous environmental and physico-chemical water quality parameters such as frequent fluctuation in pH and salinity, low dissolved oxygen, high concentrations of chemical nutrients, ability to reproduce in captivity and potential to accept natural and formulated feeds make the species most preferred and best cultured fish around the globe (Assefa & Getahun, 2015;Engdaw et al, 2013;Gule & Geremew, 2022;Suloma et al, 2017;Tesfahun & Temesgen, 2018;Tesfaye et al, 2020;Wagaw et al, 2022). Subsequently, commercial and ecological importance of Nile tilapia is undeniable especially in many top tilapia farming Asian and African countries where the demand for inexpensive protein diet is alarming exponentially (Ribeiro et al, 2018).…”

“…Apparently, studies on the food and feeding habits of fish species has become a focus of research due to strong global demand for the development of successful capture and culture fisheries management program (Gule & Geremew, 2022;Tesfahun & Temesgen, 2018). It is also essential for pond production management, formulating dietary needs of the species used in intensive and extensive culture and also in determining whether the population age structure in the fishery is in proper relation to the food resources available to it (Engdaw, 2014;Wagaw et al, 2022). Recent studies elucidated that, knowledge on feeding habits of fish enables to identify trophic interactions, composition, structure and stability of aquatic food webs (Fetahi et al, 2017;Tesfaye et al, 2020).…”

“…However, feeding habits of fish might vary due to species, age, size, maturity stage, habitat (littoral or profundal), water type and water level of the environment (Dadebo et al, 2014;Persson & Crowder, 1998). Moreover, seasonal variations and lake type have a significant influence on the feeding habits of the fish (Engdaw et al, 2013;Wagaw et al, 2022).…”

“…According to the above mentioned studies, O. niloticus in Ethiopian inland water bodies was predominantly considered as omnivorous, mainly consuming phytoplankton, zooplankton, detritus and other aquatic macrophytes. Furthermore, almost all the above studies are conducted in the rift valley lakes and their tributaries due to location and chance for comparison (Fetahi et al, 2017;Tesfaye et al, 2020;Wagaw et al, 2022). Nevertheless, there is paucity of information on the morphometric relations and feeding habits of O. niloticus from Ethiopian highland Lakes such as Lake Tana.…”