The fish fauna in the open sea, the rivers and the streams of Lesvos exhibits immense interest too. Two of these fish are threatened with extinction: the Lesbian Brianna (Barbus pergamonensis) and the Lesbian stone loach (Oxynoemacheilus theophilii). Other vulnerable species include the Marmara chub (Squalius cii) and the Smyrna chub (Petroleuciscus smyrnaeus). The Lesbian stone loach may be located on this island and nowhere else, while all other fish species may be found in Asia Minor rivers, besides Lesvos. However, due to its isolation the Lesvian populations seem to have evolved into a different subspecies from the Asiatic ones. Furthermore, on the wetlands, the salt evaporation basins and the lagoons Mediterranean killfish (Aphanius Fasciatus) may be found, an endemic species in the Mediterranean.