Feeding Strategies and Trophic Level of Chirocentrus dorab (Forsskål, 1775): A Seasonal and Ontogenetic Analysis

A total of 381 specimens of Chirocentrus dorab were analysed, among them, 346 had food content, while 9.18% had empty stomachs, with juveniles exhibiting a higher ESR (11.35%) than adults (7.14%). ESR was lowest post-monsoon (3.77%) and peaked in monsoon (25.71%). The Repletion Index (RI) was highest post-monsoon (0.0542) and lowest in monsoon (0.0124). Teleosts were the dominant prey (%QI = 84.49; %IRI = 74.19), followed by crustaceans (%IRI = 21.05) and mollusks (%IRI = 4.88). The trophic level was 4.2, with juveniles at 3.8 and adults at 4.25, indicating an ontogenetic dietary shift. The omnivory index (OI) was 0.33, higher in adults (0.39) than juveniles (0.15). Seasonal variations affected diet diversity, with species richness peaking in January (S = 8). MDS analysis revealed distinct seasonal feeding patterns, with stable post-monsoon diets and greater monsoon variability due to environmental factors. SIMPER analysis showed prey composition differences, with monsoon diets dominated by shrimps and mackerel, whereas post-monsoon and pre-monsoon diets featured sardines and anchovies. Environmental influences significantly shaped the feeding behavior of C. dorab along Karnataka’s southern coast.