Neda Mehdipour*, Mohammad Hasan Gearmi
This study was conducted to quantify the structure and composition of benthic communities on hard substrates and their relation with environmental factors in Caspian Sea basin in 2014. Sampling was done seasonally from spring to winter 2014 from 5 sites. A total of 9 taxa were recorded. Results showed that Pontogammarus maeoticus and Nereis diversicolor; and Chironomus albidus, Simulium kurense and Tabanidae hybomitra had similar distribution in Caspian Sea basin. According to BIO-ENV analysis, nitrate, silicate and temperature were the best variables (r=0.3604) for explaining changes in the abundance over time of the hard-substrates benthic fauna under study. However, the position of species in Canonical correspondence analysis plot revealed that Balanus improvises and Tubificoides fraseri associated with silicate, Mytilaster lineatus and Rhithropanopeus harrisii tridentatus associated with nitrate and others associated with oxygen in Caspian Sea basin.