''Chirostoma charari'', the least silverside, is a species of

neotropical silverside The Neotropical silversides are a family, Atherinopsidae, of fishes in the order Atheriniformes. About 112 species in 13 genera are distributed throughout the tropical and temperate waters of the New World, including both marine and freshwater h ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to Mexico. This species has only been found in a spring in the

Lake Cuitzeo Lake Cuitzeo () is a lake in the central part of Mexico, in the state of Michoacán. It has an area of . The lake is astatic, meaning the volume and level of water in the lake fluctuates frequently. It is the second-largest freshwater lake in Mexic ...

basin on the Mesa Central of the

Mexican Plateau The Central Mexican Plateau, also known as the Mexican Altiplano ( es, Altiplanicie Mexicana), is a large arid-to-semiarid plateau that occupies much of northern and central Mexico. Averaging above sea level, it extends from the US-Mexico border ...

. It has a longer head and jaw, as well as larger teeth and eyes than other ''Chirostoma'' species. Its status is rated as Critically Endangered by the IUCN, and may possibly be extinct.

References

charari Freshwater fish of Mexico Fish described in 1945 Fish of North America becoming extinct since 1500 {{Atheriniformes-stub