Trophic resource partitioning by sympatric ecomorphs of Schizopygopsis (Cyprinidae) in a young Pamir Mountain lake: preliminary results

Four sympatric ecomorphs – detritivorous, predator, benthivorous, and phytophagous – of the cyprinid fish Schizopygopsis stolickai were recorded in a young Pamir lake, Lake Yashilkul, located at > 3,700 m above sea level. Some ecomorphs are divergent in diet, gut length, and stable isotopes of δ 13 C and δ 15 N. The predator ecomorph has a shorter gut, and is the most enriched in δ 15 N (14.5‰), indicating its occupation of the highest trophic level. The lowest δ 15 N values (11.1‰) were detected in the detritivorous ecomorph. There was significant overlap in the diet of some individuals belonging to different ecomorphs, reflecting high trophic plasticity despite ongoing trophic specialization.