Commonly known as “dwarf suckers” or “otos” the Otocinclus is a type of catfish in the family Loricariidae native to South America, they are usually found in the Andes of South America, throughout the lowlands from northern Venezuela to northern Argentina, but are generally absent from the Amazon and the Orinoco lowlands. Species of this genus are diurnal and generally are found in small streams or along the margins of larger rivers, clinging to substrates using their suckermouth. The fish of this genus primarily feed on algae or aufwuchs on roots, stones, macrophytes and broad-leaved grasses.

These species have adaptations that allow them to breathe air. Otocinclus are popular aquarium fish, and they are often purchased as algae eaters.