Study of the ichthyofauna diet in the Ichkeul Lake (Tunisia)

In order to define the structure of trophic network of Ichkeul Lake in Tunisia, diet of main teleost fish species was determined during two seasons, wet and dry. A total of 491 stomachs from 16 teleost species was analyzed. The analysis revealed spatial variability (East under marine influence and West with more continental effect) and temporal one (wet and dry seasons). Based on stomach contents, nine trophic groups were revealed, including eight monospecific groups. The main prey are mudflat snails (Hydrobia ventrosa, H. acuta), bivalves (Abra alba, Cerastoderma glaucum), amphipods and isopods, as well as seagrass (Potamogeton pectinatus, Ruppia cirrhosa) and water brackish algae (Ulva spp. and Chaetomorpha spp., Cladophora sp., Polysiphonia sp.).Original Abstract: Etude du regime alimentaire de l'ichtyofaune du lac Ichkeul (Tunisie). Afin d'etablir la structure du reseau trophique du lac Ichkeul en Tunisie, le regime alimentaire des principales especes de poissons teleosteens pendant deux saisons, humide et seche, a ete determine. 491 individus appartenant a 16 especes de poissons ont ete analyses. L'analyse des contenus stomacaux a revele une variabilite spatiale (Est sous influence marine et Ouest plus continentale) et temporelle (saison humide et saison seche). Sur la base des contenus stomacaux, neuf groupes trophiques ont ete crees, dont huit sont mono-specifiques. Les principales proies sont les gasteropodes des vasieres (Hydrobia ventrosa, H. acuta), les bivalves (Abra alba, Cerastoderma glaucum), les amphipodes et isopodes, ainsi que les phanerogames (Potamogeton pectinatus, Ruppia cirrhosa) et les algues des eaux saumatres (Ulva spp. et Chaetomorpha spp., Cladophora sp., Polysiphonia sp.).