Possible effects of trophic niche overlap between Sharpbelly (Hemiculter leucisculus Basilewsky, ۱۸۵۵) and endemic fish species, Alburnus atropatenae in Zarineh River (Urmia Lake Basin, Iran)

Sharpbelly (Hemiculter leucisculus) belongs to the family Cyprinidae and has a wide distribution in inland waters of Iran. This species has been reported from Caspian Sea basin (Anzali Wetland, Sefidrood River), Urmia Lake basin, Almagol and Ajigol Wetlands, Zarivar Lake and Aras River. This exotic fish species has probably been introduced to these basins along with Chinese carp. Sharpbelly live in rivers, lakes and small ponds and feed on macrophytes, fish, crustaceans and aquatic insects. However, there is still little information about the habitat and ecological effects of this fish on endemic species. Due to the widespread distribution of sharpbelly in various aquatic species such as wetlands, lakes and rivers, it is necessary to focus on the effects of ecological niche overlap of this species with other fish, especially endemic species. Hemiculter leucisculus has been reported from Zarineh River in Urmia Lake basin with species such as Alburnus atropatenae. The coexistence of these two species can have negative effects on A. atropatenae. Hemiculter leucisculus is a potential competitor to endemic species such as A. atropatenae for access to food. With the introduction of this fish to the new habitat, the population structure of endemic fish species changes to some extent. Due to faster growth, it shows higher fertility as well as higher adaptation to environmental conditions in the ecosystem. Young fish feed on zooplankton and adults on plants, fish and insects. As a predator, H. leucisculus feeds on fish eggs and offspring and can easily change its feeding strategy from one food class to another. This is the 'r' strategy that creates dense and short-lived populations in any new environment.