1 Department of Fisheries and Marine Resources, College of Agriculture, Basrah University, Iraq.
² Basrah Agriculture Directorate, Ministry of Agriculture, Iraq.
Research Article
World Journal of Advanced Research and Reviews, 2021, 11(01), 190-202
Article DOI: 10.30574/wjarr.2021.11.1.0345
Received on 24 June 2021; revised on 25 July 2021; accepted on 27 July 2021
The present study objectified to evaluate the trophic relationships among 14 fish species (10 natives and 4 non-natives) in the Shatt Al-Arab River, considering the trophic niche breadth and the diet overlaps of the species. The food items in the stomach of each species are determined by adopting the index of relative importance (IRI). The dietary analysis revealed a total of 12 types of major food items consumed (which represent >10% IRI). Two species (Oreochromis aureus and Cptodon zillii) were herbivores consumed mostly macrophytes, algae and diatoms. Four species (Planiliza abu, P. klunzengeri, P. subviridis and Osteomugil speigleri) were herbivores mainly fed on diatoms, macrophytes, detritus and algae. Three species (Carasobarbus luteus, Carassius auratus and Cyprinus carpio) were omnivores mostly consumed macrophytes, detritus, diatoms and algae. Two species (Tenualosa illisha and Nematalosa nasus) were filter feeders fed largely on zooplankton, algae, detritus and macrophytes. Three species (Acanthopagrus arabicus, Johnius belangerii and J. dussumeiri) were carnivores mainly preyed on shrimps, crabs and fish. Levin’s index diet breadth analyses divided the studied fish species into three categories; two species with high specialization, five species with low specialization, and seven species with generalization feeders. The dietary composition of fish species exhibited 62 diet overlaps as indicated by the Jaccard index, eight of them high, 36 moderate and 18 low overlaps. Only J. dussumeiri and J. belangerii have no diet overlap with other species. Overall, the study demonstrates that most trophic overlaps between species were moderate, but high degree overlap was between the native species (C. luteus) and invading species (C. auratus) and therefore strengthen earlier conclusions regarding interspecific competition between these two species.
Diet composition; Dietary overlap; Trophic niche breadth; Shatt Al-Arab River; Iraq
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Abdul-Razak Mahmood Mohamed and Abdullah N Abood. Trophic relationships among fourteen native and non-native fish species in the Shatt Al-Arab River, Iraq. World Journal of Advanced Research and Reviews, 2021, 11(1), 190-202. Article DOI: https://doi.org/10.30574/wjarr.2021.11.1.0345