David Giraud Akélé, Hypolithe Agadjihouédé, Buenas Agbohozo and Philippe Lalèyè

Variations in the diet of the oyster Etheria elliptica were studied over a daily cycle at the Pendjari River. Stomach content items were identified. Diet composition was analyzed using the point alloted method. The oyster fed mainly of phytoplankton (99.55%) and zooplankton (0.41%). The Diatoms Coscinodiscus rudolfii (31.73%) and Eunotia bilunaris (23.93%) constitute the preferential foods, while the Cyanophytes (Microcoleus lacustris, 14.15%) and the Chlorophytes Stigeoclonium aestivale (10.64%) and Gonatozygon monotaenium (9.13%) are the secondary foods. The other are additional food items. On the daily cycle, the trophic activity is intense almost all day with a preference for the night hours between 6 p.m -12 a.m. The diet compositions showed significant variations between the hours of the day (9 a.m. to 6 p.m.) and night (9 p.m. to 6 a.m.). Etheria elliptica is a phytophagous with a varied trophic activity, feeding mainly on diatoms. The trophic activity intensifies during the night hours.

DOI: 10.22271/23940522.2022.v9.i3a.903

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