Hypoptopomatinae

Hypoptopomatinae
Otocinclus cocama
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Loricariidae
Subfamily: Hypoptopomatinae
C. H. Eigenmann & R. S. Eigenmann, 1890
Genera

Tribe Hypoptopomatini
  Acestridium
  Hypoptopoma
  Lampiella
  Leptotocinclus
  Nannoxyropsis
  Niobichthys
  Otocinclus, inc. Macrotocinclus
  Oxyropsis
Tribe Neoplecostomini (sometimes elevated to subfamily as Neoplecostominae)
  Hirtella
  Isbrueckerichthys
  Kronichthys
  Microplecostomus
  Neoplecostomus
  Pareiorhaphis
  Pareiorhina
Tribe Otothyrini (sometimes elevated to subfamily as Otothyrinae)
  Corumbataia
  Curculionichthys
  Epactionotus
  Eurycheilichthys
  Hisonotus
  Microlepidogaster
  Otothyris
  Otothyropsis
  Parotocinclus
  Pseudotocinclus
  Pseudotothyris
  Rhinotocinclus
  Schizolecis
incertae sedis
  Chauliocheilos
  Euryochus
  Plesioptopoma
  Rhinolekos

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

It has been divided 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. 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. Problematically, the most recent Hypoptopomatine genera, Gymnotocinclus and Rhinolekos, were not classified in either of the tribes. Gymnotocinclus was subsequently invalidated when it was synonymised with Corumbataia in 2019.

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

Hypoptopomatinae are distributed east of the Andes in South America from Venezuela to northern Argentina. 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.