Identification of macrofauna in the Achiroud River in Chaboksar area, Gilan province

Document Type : Research Paper


1 Department of Marine Biology, Marine Science and Technology College, North Tehran Branch, Islamic Azad University, Tehran, Iran

2 Department of Biology, Biological Sciences College, Varamin-Pishva Branch, Islamic Azad University, Varamin-Pishva, Iran


Macrobenthos are known as biological indicators of their living environments and can be used as index of water pollution in different water resources. Achiroud River located in Gillan province and its macrofauna has not been studied yet. So, in the present study, the macrofauna of the Achiroud River in the winter 2015 and spring 2016 was examined. Sampling was performed in two seasons of winter 2015 and spring 2016. Five stations were selected based on geographical characteristics of the river and each station using GPS system. Sampling was quadratic and seasonal. The Hilsenhoff index was determined based on the presence of benthos at each station. The water pollution was determined using the Hilsenhoff index in each station in spring and winter. The macrobenthos classified into 3 classes, 12 families and 14 species and identified. The most frequency was related to insects and the lowest frequency belonged to Malacostraca. The highest frequency in the winter belongs to the Gammaridae (Gammarus sp.) and in the spring belonged to the two families Gammaridae and Heptageniidae (Gammarus sp. and Ecdyonurus venosus). Species of Gammarus sp. and Ecdyonurus venosus were present at the most stations in two seasons. The highest value of Hillsenhof index was (5.22) observed in winter and the lowest value of this index was related to spring (0.71). According to the HFBI bio-index, water quality in stations 3 and 5 was excellent, in stations 4 was very good and in station 2 was intermediate.