Biodiversity of Fishes in Tajan River (Mazandaran Province)

Diversity, abundance and distribution of fishes in Tajan River were studied from March 2008 to July 2009. Tow sampling stations were selected along the River in up and down of the Shahid Rajaii Dam. A total of 2996 specimens were caught using electrofishing. The specimens were belonged to 9 species from 4 families: Capoeta capoeta gracilis, Alburnoides bipunctatus, Barbus mursa, Barbus lacerta, Luciobarbus capito, Squalius cephalus, Cobitis taenia, Paracobitis malapteruraandNeogobius fluviatilis. The results showed that species diversity and richness index coefficients of the upstream station of the dam were lower than those of the downstream station (P<0.05), but there were no significant differences in dominance and similarity indices between the two stations. The present study indicates that the dam, as a human-made construction, has influenced the fish diversity in up- and down-stream of the river.