Chirostoma charari

Chirostoma charari, the least silverside, is a species of neotropical silverside endemic to Mexico. This species has only been found in a spring in the Lake Cuitzeo basin on the Mesa Central of the Mexican Plateau. 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.