Species diversity of macrobenthos as live food in the ecosystem of Fusheh River, Northern Iran

Species diversity of macrobenthos in Fusheh River, in Guilan Province, North Iran was studied and biological indices developed based on macroinvertebrates were used to evaluate the health status of the river. Macrobenthos sampling in the river was carried out at 4 stations on a monthly basis beginning from May to December 2016 using a Sorber sampler (mesh size of 300 μm and surface area of 900 cm2) with three repetitions. The sampled macrobenthos were preserved in 96% ethanol and transported to the laboratory for identification. A total of 4928 individuals from two phyla of Arthropoda and Annelida, three classes of insects (Insecta), crustaceans (Crustacea) and Clitellata as well as 8 orders (including Ephemeroptera, Trichoptera, Plecoptera, Diptera, Coleoptera and Haplotaxida) along with 25 families and 31 genera were identified. The most abundant genera were Simulium sp. (35.84-46.65%), Hydropsychae sp. (15.79-33.36%) and Baetis sp. (7.87-17.66%). Parameters of total abundance, EPT richness, EPT percentage and EPT/CHIR ratio were also calculated. The EPT richness showed a significant difference in monthly samplings (p<0.05). The presence of species sensitive to pollution such as Perla sp., Isoperla sp., Chloroperla sp., Oligoneuriella sp., Heptagenia sp., Rithrogena sp., Epeorus sp., Rhyacophila sp. and Philorus sp. belonging to orders Trichoptera, Plecoptera and Ephemeroptera exhibits both the good quality of river water and the desirability of species and genera as natural food for the river fish species.