Hydrology and Hydrobiology of Chaloos River

The Chaloos river originates from Alborz mountain and enters into the Caspian Sea in ChaJoos city. Five stations were chosen in different areas for the study during 1371 to 1372 (1992-93). Total v'ariation range of hardness dccrcased 1 to 5 station, but measure NH4 and NO3 increased. 45 genera belongs to 4 phyla of phytoplankton as follows: Chrysophyta, Chlorophyta, Euglenophyta and Cyanophyta. Zooplankton existing in this river belong to animal classes, which had morc abundance in Sarcodina and Monogononta. The Benthos river establish Insecta larvae of Ephemeroptera, Coleoptera, Diptera, Plecoptera and Odonata (Orders). Chaloos fishes included to 4 families, 10 genera and 12 species. Cyprinidac consisted 66.7% of total fish and had maximum diversity at the various stations