Cui-ui

The cui-ui, Chasmistes cujus, is a large sucker fish endemic to Pyramid Lake and, prior to its desiccation in the 20th century, Winnemucca Lake in northwestern Nevada. It feeds primarily on zooplankton and possibly on nanoplankton (such as algae and diatoms). The maximum size of male cui-ui is approximately 53 cm (21 in) and 1.6 kg (3.5 lb), while females reach approximately 64 cm (25 in) and 2.7 kg (6 lb). The life span of cui-ui is typically about forty years, but the fish do not reach sexual maturity until at least age eight. The cui-ui is not only a critically endangered species, but is also one of the few surviving members of its genus.