Labeoninae is a doubtfully distinct subfamily of ray-finned fishes in the family Cyprinidae of order Cypriniformes. They inhabit fresh water and the largest species richness is in the region around southern China, but there are also species elsewhere in Asia, and some members of Garra and Labeo are from Africa. They are a generally very apomorphic group, perhaps the most "advanced" of the Cyprinidae. A common name for these fishes is labeonins (when considered a distinct subfamily) or labeoins (when included in subfamily Cyprininae).
They include the group sometimes separated as Garrinae, but these do not seem to be that distinct. In fact, the entire Labeoninae is merged into the Cyprininae by a number of authors; in any case, these two and the former "Barbinae" form a close-knit group whose internal phylogeny is far from resolved. If the subfamily is considered distinct, it is typically split in the tribes Labeonini (which are able to swim well in open water) and Garrini (which are mostly benthic), and sometimes in addition the Banganini (which are somewhat intermediate in habitus) If the labeo lineage is included in the Cyprininae, it becomes the tribe Labeonini, while its two (or three) subdivisions are the subtribes Labeoina, Garraina and perhaps Banganina.
Notable genera are Crossocheilus, Epalzeorhynchos and Garra, which contain some of the popular aquarium fishes often called "algae eaters", e.g. the Siamese algae-eater (Crossocheilus siamensis). Labeo – the type genus of this subfamily – contains many sizeable species which are often used as food.
Anatomically, the labeonins are distinguished by the Weberian apparatus contacting the skull with the supraneural bones, and its basioccipital process being concave in cross-section. The first vertebra has a parapophysis that is elongated to forward and partially overlaps the basioccipital process. The fourth vertebra, meanwhile, has a short but stout transverse process that is prominently elongated bellywards; the os suspensorium is often hidden behind if viewed from the side. In the skull, the frontal and sphenotic bones have prominent foramina. In the anal fin, the first pterygiophore is elongated and has well-developed anterior and posterior flanges, with the former very large and concave at the distal end. Most labeonins have the skinny flap of the underside of the snout well-developed into a fleshy cap that at least partially hides the upper lip except when feeding, and a similar structure at the lower lip.
Genera
Tribe Labeonini
Barbichthys Bleeker, 1860
Cirrhinus Oken (ex. Cuvier), 1817 (tentatively placed here) Henicorhynchus Smith, 1945 Labeo – typical labeos Labiobarbus van Hasselt, 1823 (including Dangila?) Nukta Hora, 1942 Osteochilus Günther, 1868 Prolixicheilus Zheng, Chen & Yang, 2016 Pseudogyrinocheilus Fang, 1933 Schismatorhynchos Bleeker, 1855 Sinilabeo Rendahl, 1932 Tribe Banganini (might belong in Labeonini) Bangana Hamilton, 1822 (tentatively placed here) Lobocheilos (tentatively placed here) Qianlabeo Zhang & Chen, 2004 Speolabeo Kottelat, 2017 Vinalabeo Nguyen, Nguyen & Nguyen, 2016
Tribe Garrini
Crossocheilus van Hasselt, 1823
Discocheilus Zhang, 1997
Discogobio Lin, 1931 (tentatively placed here) Discolabeo Fowler, 1937 Epalzeorhynchos Garra – garras Hongshuia Zhang, Xin & Lan, 2008 Horalabiosa Silas, 1954 Iranocypris Longanalus Li, 2006 (tentatively placed here) Mekongina Fowler, 1937 Parasinilabeo Wu, 1939 Paracrossochilus Popta, 1904 Pseudocrossocheilus Zhang & Chen, 1997 Ptychidio Myers, 1930 Rectoris Lin, 1933 (tentatively placed here) Semilabeo Peters, 1880 (tentatively placed here) Sinocrossocheilus Wu, 1977 Tariqilabeo Wu, 1977 Typhlogarra Trewavas, 1955 Vinagarra Nguyen & Bui, 2010
The supposed genus "Tylognathus", commonly placed in the Labeonini (or Labeoina), is actually a polyphyletic assemblage containing diverse labeonins and some other cyprinids. Its type species, variously called "Tylognathus diplostoma" or "Tylognathus valenciennesii", is actually Bangana diplostoma; most of its other species are now in Lobocheilos.