Trophic relationships among fourteen native and non-native fish species in the Shatt Al-Arab River, Iraq

The present study objectified to evaluate the trophic relationships among 14 fish species (10 natives and 4 non-natives) in Shatt Al-Arab River, considering niche breadth diet overlaps of species. food items stomach each are determined by adopting index relative importance (IRI). dietary analysis revealed a total 12 types major consumed (which represent >10% IRI). Two (Oreochromis aureus Cptodon zillii) were herbivores mostly macrophytes, algae diatoms. Four (Planiliza abu, P. klunzengeri, subviridis Osteomugil speigleri) mainly fed on diatoms, detritus algae. Three (Carasobarbus luteus, Carassius auratus Cyprinus carpio) omnivores detritus, diatoms (Tenualosa illisha Nematalosa nasus) filter feeders largely zooplankton, algae, macrophytes. (Acanthopagrus arabicus, Johnius belangerii J. dussumeiri) carnivores preyed shrimps, crabs fish. Levin’s analyses divided studied into three categories; two with high specialization, five low seven generalization feeders. composition exhibited 62 as indicated Jaccard index, eight them high, 36 moderate 18 overlaps. Only dussumeiri have no overlap other Overall, demonstrates that most between moderate, but degree was native (C. luteus) invading auratus) therefore strengthen earlier conclusions regarding interspecific competition these