Alosa vistonica Alosa vistonica Alosa vistonica is a species of shad, a freshwater fish in the Clupeidae family. It is endemic to a single shallow lake, Lake Vistonida in Greece. It is classified as critically endangered (CR) and is threatened by sewage, industrial effluents, destruction of spawning sites by agricultural development and increased salinity following the opening of a canal into the sea. It has been suspected to be extinct already. "A. vistonica" reaches a maximum length of 17 cm (SL). It is distinguished from other members of its genus entering freshwater of the Mediterranean basin by having 78-97 gill rakers and
Cisco (fish) Cisco (fish) The ciscoes (or "ciscos") are salmonid fish of the genus "Coregonus" that differ from other members of the genus in having upper and lower jaws of approximately equal length and high gill raker counts. These species have been the focus of much study recently, as researchers have sought to determine the relationships among species that appear to have evolved very recently. The term "cisco" is also specifically used of the North American species "Coregonus artedi", also known as lake herring. In previous taxonomic classifications, the ciscoes have been identified as a subgenus "Leucichthys" of the genus "Coregonus". Based