İznik shemaya
The İznik shemaya is an extinct species of freshwater ray-finned fish belonging to the family Leuciscidae. This species was endemic to Lake İznik in Turkey. It has not been found since the late 20th century, and is now presumed extinct by the IUCN. It is most likely that this species became extinct with the introduction of the big-scale sand smelt to Lake İznik.