Lamontichthys is a genus of whiptail catfish in family Loricariidae, subfamily Loricariinae - the armored catfish lineage known for a slender, elongated body and a long, tapering tail rather than the stockier shape of typical plecos. Atlas records span Brazil, Ecuador, Peru, Venezuela, Bolivia, and Colombia, and the six species run 5–8 in, a middling size within the whiptail group. Like other loricariines, Lamontichthys has a flattened head, a ventral sucking mouth for grazing algae and biofilm, and lives in fast-flowing rivers and rapids where its low, streamlined profile helps it hold position against strong current.
Several species carry elaborate finnage that draws specialist pleco and whiptail keepers - the Sailfin Whiptail (L. stibaros) and Maracaibo Sailfin Whiptail (L. maracaibero) both develop a tall, extended dorsal fin, while the Filament Whiptail (L. filamentosus) is named for drawn-out fin rays - and these fish are kept in strong-current, well-oxygenated tanks with driftwood and algae growth to graze, much like Rineloricaria and Sturisoma whiptails. Conservation status is mixed: three of six species are Least Concern, but one is Endangered and one Vulnerable, with a further Data Deficient, pointing to real pressure on some of these river-rapid specialists from damming and habitat change.