Abstract: The present study showed that the population density of a native fish (A. dispar) in the freshwater environments of Saudi Arabia is declining. It is concluded from the present investigations that A. dispar is not threatened by a single isolated factor, but instead faces numerous stressors that jeopardize multiple stages of their life cycle. Reduced availability of food, habitat degradation, chemical contamination, introduction of exotic species and exploitation have contributed to the decline of such native fish`s abundance. Protecting fishes will help to protect aquatic biodiversity and in conservation of biological heritage of the country.