Rineloricaria is a genus of whiptail catfish in the family Loricariidae, distributed across much of tropical and subtropical South America, with atlas records from Brazil, Colombia, Argentina, Uruguay, Venezuela, Guyana, Paraguay, and Bolivia. The 71 species in the atlas range widely in size, from 5.4 up to 14 in, and share the genus's namesake trait: a long, slender, whip-like tail extending well past a flattened, armour-plated body, an adaptation that suits life resting on sand and gravel substrate in slow to moderate current.
Like other suckermouth armored catfish, Rineloricaria species graze algae and biofilm with a ventral sucker-mouth, and several, sold in the trade as whiptail or royal whiptail catfish, including species such as Rineloricaria eigenmanni and R. lanceolata, are popular in planted community aquaria for their peaceful temperament and algae-eating habits, generally coexisting well with other fish more readily than bulkier plecos. As in other loricariids, breeding males grow bristly odontodes on the head and pectoral fins, and guard a clutch of eggs laid inside a cave or length of pipe until they hatch.
Most Rineloricaria species assessed by the IUCN are Least Concern, and the genus as a whole carries a comparatively low conservation profile, though a few species are Vulnerable or Endangered and a meaningful share remain Data Deficient or Not Evaluated, reflecting how many whiptail catfish are still known from limited field survey data.