شناسايي بي مهرگان كف زي رودخانه زاينده رود

The Identification of Benthic Invertebrates of Zayandeh-Rood River

Between 1998 and 2000 in about 170 Km., along the river course, 14 sites were selected and the benthos of each site were sampled seasonally, using dredge sampler. Sorting out the samples were done in the laboratory and the taxa of each sample were identified to the species level if possible. The results of 168 benthic samples studied in this research included 40 taxa and 26 species from 13 orders, 28 families Band 26 genera. From the 13 orders, Ephemeroptera, Trichoptera and Gastropoda were the most diverse, from the number of family, genus and species point of view respectively, but others had no considerable diversity. The genera and species of some families such as Chironomidae, Baetidae, Gammaridae, Erpobdellidae and Oligochaeta were present almost in all sites and seasons. In contrast the genera and species of some families such as Elmidae, Caenidae, Potatnanthidae and Perlodidae were present in some sites and seasons, which could be caused by their life cycles, or their specific site requirements.