Diet composition and trophic interactions of nine fish species from Mocha water, southern Red Sea, Yemen

Abstract

Lethrinus lentjan, Lethrinus nebulosus, Lethrinus borbonicus, Lethrinus microdon, Sphyraena jello, Scomberomorus commerson, Euthynnus affinis, Carangoides chrysophrys and Caranx sexfasciatus are important fish of artisanal fishery of Mocha. In this area, no data is available on the biology and feeding ecology of these species. From May 2014 to June 2015, fish specimens (789) were sampled from the main fishing-landing site. Total length and total weight were measured and stomach contents were analyzed to evaluate the trophic interactions that exist between these species. Fish prey dominated in diets of all species except of L. nebulosus and L. lentjan, which mainly fed on mollusks. Based on diet similarity, four fish groups were identified: one includes L. microdon, C. chrysophrys, E. affinis and L. borbonicus, the other includes C. sexfasciatus, S. jello and S. commerson. Individually, L. lentjan and L. nebulosus form two separate groups. High dietary overlap was obtained among most species, associated with the dominance of small fish pelagic prey, perhaps because its abundance in the area, this implies a generalized and opportunistic utilization of resources.