Diet composition and feeding habits of the African sharptooth catfish Clarias gariepinus (Burchell, 1822) from Ribb Reservoir, South Gondar, Ethiopia

Abstract

A total of 525 catfish samples were collected with various fishing equipment, including hooks, longlines, and different mesh sizes of gillnets (4–12 cm). Out of these specimens, 379 (72.2%) stomachs contained prey items, whereas 146 (27.8%) were empty stomachs. Overall, fish prey, zooplankton, detritus and phytoplankton were the four most important food items, accounting for 48.1%, 21.8%, 17.1% and 5.9% of C. gariepinus diets by volume respectively. Diet composition varied across different size classes of the fish. The smallest fish (<37 cm standard length) mainly consumed detritus, mud (sediment), and zooplankton which comprise 41.2%, 29.3%, and 19.8% of the total volume, respectively. The larger fish (>37 cm SL) primarily fed on fish prey (14.0–74.1%) followed by zooplankton (11.2–21.3%) by volume. The relative importance of detritus, mud, zooplankton, phytoplankton, and insects decreased with increasing fish size from the Ribb Reservoir. The food and feeding habits of C. gariepinus significantly differed between dry and wet seasons. Fish prey and detritus were mainly consumed in the dry season and contributed to 63.6% and 21.9% of the total volume respectively. Zooplankton and phytoplankton were the most preferred food items during the wet season, contributing 71.8% and 22.2% of the total volume. Generally, C. gariepinus appears to be an omnivore, the species exhibits ontogenetic dietary shifts with larger specimens being more carnivorous, and the species exhibits dietary plasticity across wet and dry seasons, which may be linked to food availability from the Ribb Reservoir.

Keywords:

• Catfish
• Detritus
• Diet preferences
• Diet composition
• Ethiopia
• Ribb Reservoir

PUBLIC INTEREST STATEMENT

Ethiopia’s agricultural sector is still insufficient to supply food to this fast growing population. Clarias gariepinus African sharptooth mudcatfish is one of the most commercially important fish species in Ethiopia. Fisheries and aquaculture are alternatives to meet the high protein demand. The African catfish Clarias gariepinus (family Clariidae) is one of Ethiopia’s most important commercial fisheries. Understanding fish feeding habits and their trophic interactions within food webs is important for fisheries management and establishing sound aquaculture practices. The food and feeding habits of this fish species is impacted by the expansion of irrigation practices such as high sedimentation load, poor land use practice, lack of vegetation cover, and the construction of dams and weirs within the rivers. This fish resource is not well utilized due to the scientific knowledge gap. Therefore, water buffer zone management is needed to improve food and feeding habits of this fish species for better sustainable utilization.

Acknowledgments

We thank the Guna Tana Integrated Field Research Development Centre Debre Tabor University for helping financial provision and vehicle support. We also thank the fishermen of Ribb Reservoir for the helping with the sampling of fish specimens.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author’s contribution

Agumassie Tesfahun: Conceptualization, Methodology, Software: Agumassie Tesfahun. Data curation, writing-original draft preparation. Agumassie Tesfahun Visualization and Investigation. Sale Alebachew, Supervision.: Agumassie Tesfahun Software, Validation.: Sale Alebachew and Agumassie Tesfahun: Writing- Reviewing and Editing

Availability of data

All the data sets used in this manuscript are accessible in the corresponding author via upon a reasonable claim

Additional information

Notes on contributors

Agumassie Tesfahun

Agumassie Tesfahun received his MSc Degree in Fisheries, Limnology, and Aquatic-eco-toxicology from Hawassa University, Ethiopia. Currently, he is the Assistant Professor at the Department of Biology, Debre Tabor University, Ethiopia. Besides, he has been working in community service and research on fisheries biology of the most commercially important fish species from Ribb Reservoir Tana basin, Ethiopia, and aquaculture establishment (earthen pond system) from Fogera District, South Gondar, Ethiopia.

Sale Alebachew

Sale Alebachew was awarded his MSc Degree in Animal Production from Debre Markos University, Ethiopia. Now, he is a lecturer and researcher at the Department of Animal Sciences, Debre Tabor University, Ethiopia. Moreover, he has been working on fisheries biology of the most commercially important fish species from Ribb Reservoir Tana basin, Ethiopia, and aquaculture establishment (earthen pond system) from Fogera District, South Gondar, Ethiopia.