Hypoptopomatinae

The Hypoptopomatinae are a subfamily of catfishes (order Siluriformes) of the family Loricariidae,^[2] composed of 32 genera and approximately 265 species.^[3] This subfamily represents about one-tenth of all loricariid species.^[4]

Eschmeyer's Catalog of Fishes does not recognise tribes within the Loricariidae,^[5] but other authorities have divided this taxon into three tribes, Hypoptopomatini, Neoplecostomini and Otothyrini. However, in a 2005 analysis, Otothyrini was found to not be monophyletic, with its representatives comprising a paraphyletic group in relation to the tribe Hypoptopomatini.^[6] More recent phylogenetic evidence shows that Hypoptopomatini and Otothyrini, while each are monophyletic tribes, do not form a monophyletic subfamily, and therefore should each be recognized as their own individual subfamilies.^[7] Problematically, the most recent Hypoptopomatine genera, Gymnotocinclus and Rhinolekos, were not classified in either of the tribes.^[8][9] Gymnotocinclus was subsequently invalidated when it was synonymised with Corumbataia in 2019.^[10]

Almost all species of Hypoptopomatinae have a diploid number of 2n = 54; this group is karyotypically very conserved.^[11]

Hypoptopomatinae are distributed east of the Andes in South America from Venezuela to northern Argentina.^[12] Most of the hypoptopomatine species are usually found at or near the water surface, typically in close association with riverbank vegetation or some subsurface structure.^[13]