Diet of the cassava croaker (Pseudotolithus senegalensis) (Valenciennes, 1833) (Sciaenidae) from the Senegalese coast, West Africa: effects of season, maturity stage, sex and location on diet

Diouf, Khady; Ba, Abdoulaye; Ndiour, Yacine

doi:10.21608/ejabf.2021.152678

Diet of the cassava croaker (Pseudotolithus senegalensis) (Valenciennes, 1833) (Sciaenidae) from the Senegalese coast, West Africa: effects of season, maturity stage, sex and location on diet

Document Type : Original Article

Authors

10.21608/ejabf.2021.152678

Abstract

The current study was conducted at two sites; Joal and Mboro to evaluate the effects of season, sex, maturity stage, and location on the diet of the cassava croaker (Pseudotolithus senegalensis) (Valenciennes, 1833). The two study sites, located on Senegalese coast, were chosen for the estuary ecosystem and marine ecosystem, respectively. Prey diversity and feeding strategy were evaluated. Multivariate analysis was performed to test the influence of sex, season, location, and maturity stage on this species’ diet. The study extended from August 2015 to July 2016 and revealed that of the 606 stomachs examined in both sites 577 (16.03%) contained food. Cumulative prey diversity curves reached a stable level at 225 stomachs in Mboro and 275 in Joal, and thus the sample size was large enough to describe the overall cassava croaker diet. IRI% index was used to describe the overall diet of the cassava croaker. Hence, a clear dominance of teleosts and crustaceans prey items in the stomach contents analyzed in both sexes, in both locations, in all seasons and at all maturity stages was monitored. In the diet, relevant differences were found between sexes, maturity stages, sampling seasons and locations. Those food shifts are probably related to morphological limitations and abilities associated with the feeding habits of the cassava croaker. In Joal and Mboro, the trophic level of Pseudotolithus senegalensis was 4.04 and 4.15, respectively. Though the present findings showed that this species is a vigorous carnivorous predatory feeder, yet the wide range of prey items identified suggests an opportunist feeding behaviour. Moreover, this species also feeds on algae, organic debris and other invertebrates.