Faunistic study of exotic fishes in Rivers of Tehran province

Iran is located in the region of important animal geographical exchanges in terms of climate and therefore it has a diverse and interesting fauna of fish. This study investigates the faunistic of exotic fish species in the rivers of Tehran province (Jajrood, Hablehrood, Namrood and Lar). During this study, which was conducted in autumn and winter of 2016 and spring and summer of 2017, seasonal sampling of fish was performed using electroshock device and manual and waiting nets in twelve stations in the rivers of Tehran province. After catching, the samples were fixed with formalin and transferred to the laboratory for biometry and were identified by valid identification keysThis study showed that 7 species belonging to 6 genera and 3 families from 3 orders belonging to the classification of bony fish were identified. In terms of number of species, the rainbow trout (Oncorhynchus mykiss) was in the first place and the carp or pond carp (Carassius carassius) was in the second place. The species Salvelinus fontinalis, Alburnoides eichwaldii, Capoeta aculeate, Carassius auratus and xynemacheilus angorae were also caught in the studied rivers. The largest number of exotic species in the rivers were: Lar > Jajrood > Hablehrood = Namrood. No non-natives were found at Fasham, Khamdeh and Pleur stations. No exotic was found at Fasham, Khomedeh and Polour stationsThe results indicate the spread of exotic fish species in the rivers of Tehran province intentionally and unintentionally. The fish may compete with endemic fish for food and spawning sites. Some of them are even able to produce hybrids with endemic fish, they may hunt native fish or affect the native fish population as a source of disease, and in this regard it is very important to identify them and study their effects on water resources.