Parotocinclus is a genus of small armored catfishes in the family Loricariidae, in the same otocinclus-like subfamily, Hypoptopomatinae, as Hisonotus and Otocinclus; the atlas's records center on Brazil with additional species from Colombia, Guyana, Suriname, Venezuela, and French Guiana. Its species share the family's flattened, bony-plated body and ventral sucker-mouth adapted for rasping algae and biofilm from rocks, wood, and leaf litter in shallow, well-oxygenated streams. The atlas covers 30 species with adult sizes from about 1–2.5 in, making Parotocinclus one of the genuinely dwarf catfish genera, several species barely larger than a fingernail as adults, and body patterning across the genus tends toward mottled or spotted browns and creams that blend into a leaf-litter substrate.
In the hobby, Parotocinclus occupies much the same niche as its better-known relative Otocinclus: a small, peaceful, algae-grazing catfish well suited to nano and planted tanks, though far fewer of its species are regularly available in the trade. Named species such as the Spotted Dwarf Pleco (Parotocinclus spilosoma) and the Goby Pleco (P. jumbo) turn up occasionally under those trade names, while most others in the atlas circulate rarely if at all. Conservation status is reassuring across most of the genus, with the large majority of assessed species rated Least Concern; a small number are Data Deficient, and Parotocinclus arandai is listed as Endangered, again a reminder that a mostly secure genus can still hold individually vulnerable, narrow-range species.