Feeding ecology of Tropidophoxinellus callensis (Cyprinidae) in Algeria

Understanding species diet is crucial for comprehending ecosystem functions and trophic dynamics within food webs. The Maghreb b leak Tropidophoxinellus callensis (Guichenot, 1850 ) ( Cypriniformes, Cyprinidae) is an endemic fish species with populations isolated in Algeria and Tunisia. Unlike other species within the genus, ecological studies on the Maghreb b leak, particularly regarding its diet, are lacking. This study analyzed the diet composition of the Maghreb bleak over an annual cycle in northeastern Algeria. Diet analysis was conducted by examining the contents of 212 digestive tracts collected during seasonal sampling from February to September 2023. The diversity of the Maghreb bleak 's diet was assessed based on the presence and abundance of each prey, differentiating between terrestrial and aquatic prey. Additionally, Costello’s graphical method was utilized to evaluate potential prey and feeding strategies. Results indicate that insects (relative abundance = 86.1%) were more prevalent in the diet compared to plant material (relative abundance = 7.1%). The diet composition was more diverse in summer (Shannon-Weaver index H' = 4.43) and less diverse in spring (Shannon-Weaver index H' = 1.04). The Maghreb bleak exhibits a diverse diet with an omnivorous feeding strategy. The main prey and their abundance varied seasonally, with a consistent preference for dipteran larvae, namely, Chironomus sp. and Simuliidae sp. and plant material of Alnus glutinosa as predominant prey items throughout the year. The species also demonstrated opportunistic feeding behavior when these primary prey types were less abundant. These findings provide significant insights into the feeding ecology of th e Maghreb bleak , with implications for understanding its role in the ecosystem and infor m ing conservation efforts.