Ichthyofauna and some biological indices in Karoon, Dez and Bahmanshir Rivers (southwest of Iran)

During one year survey (1992-1993) 47 different species of fishes were caught by drift gill net from Bahmanshir, Karoon and Dez rivers. Distribution, frequency, ecological indices (diversity, richness and dominance), salinity coefficient (for Karoon and Bahmanshir rivers) were also calculated. In Karoon Rivers 32 species, in Bahmanshir 25 species and in Dez 12 species were identified. Freshwater fishes of Karoon include 17.9%, Bahmanshir 5.9% and Dez 14.6% of total freshwater fishes in Iran. Among identified fishes 4 nor endemic species, 2 anodermus species and the rest are dwelled and one species is rare. The most frequent species were: Clupeidae (3 genus and 3 species) in Bahmanshir river, and Cyprinidae (10 genus 16 species) in Dez river and (12 genus and 19 species) in Karoon river. Also the maximum fish abundance was in autumn, in Bahmanshir and Dez rivers and in spring in Karoon River. The similarity percentage of species between Karoon and Bahmanshir was very low. The maximum diversity and evens also belong to Bahmanshir and the maximum species richness and dominance belong to Karoon River.