Fish species diversity in the lakes of Alma-Gol,Adji-Gol,and Ala-Gol,Golestan province,northern Iran

The study was conducted to explore fish species diversity and understand some ecological aspects of the lakes of Golestan province, which represent a group of the small and rather isolated water bodies, from September 2000 to August 2002. With respect to environmental properties, there were no significant differences among wetlands. The results revealed that non-indigenous fish species are found to be dominant in the lakes. Of ten sampled species, four, including sharp belly Hemiculter leucisculus, silver crucian carp Carassius auratus, top mouth gudgeon Pseudorasbora parva, and mosquito fish Gambusia holbrooki, were non-indigenous. Observation of sharp belly and top mouth gudgeon represent actually the first record of these species in these lakes. Endemicism was highest in Adji-Gol (52.37% native) and much lower in Alma-Gol (10.20%) and Ala-Gol (20.43%). Species richness, diversity, and evenness were highest in Adji-Gol and lowest in Ala-Gol. Dominance of non-indigenous species could be explained by their wider ecological and physiological tolerance; therefore, if greater emphasis is not placed on the conservation of native fishes, these species could face continued declines or might be quietly lost in the lakes. The text was submitted by the authors in English.