Gymnostomus ornatapinnis (ROBERTS, 1997)

SynonymsTop ↑

Cirrhinus ornatipinnis Roberts, 1997; ? Cirrhinus soi Roberts, 1997

Etymology

Gymnostomus: from the Ancient Greek γυμνός (gumnós), meaning ‘naked’, and στόμα (stóma), meaning ‘mouth’, presumably in reference to the lack of barbels in this genus.

ornatapinnis: from the Latin ornatus, meaning ‘decorated, adorned’, and pinna, meaning ‘fin’, in reference to the colourful fins in this species compared with other members of the genus.

Classification

Order: Cypriniformes Family: Cyprinidae

Distribution

Known only from the Mekong River system in Laos, Thailand, and Cambodia. It does not appear to have been recorded from Vietnam.

Type locality is ‘Roadside ditch on highway 24 at kilometer 150 marker, 179 kilometers by road east of Nakorn Ratchasima, northeastern Thailand’.

Habitat

This species has not been collected from major river channels to date, and appears to display a preference for still or slow-moving, often temporarily-inundated, marginal habitats.

Maximum Standard Length

90 – 100 mm.

NotesTop ↑

G. ornatapinnis can be distinguished from congeners by the following combination of characters: head small; snout relatively short and blunt; caudal peduncle very deep; pectoral, pelvic, and anal fins usually reddish-orange or rose-tinted; pelvic and anal fins often with white tips; barbels completely absent.

Species currently included in Gymnostomus have previously been placed in a variety of genera including Henicorhynchus, Cirrhinus, Bangana, and Labeo in the last few decades alone. However, Gymnostomus is a senior subjective synonym of Henicorhynchus, thus rendering the latter invalid, while Gymnostomus is easily distinguished from Cirrhinus by possession of 8-9 (vs. 10-15) branched dorsal-fin rays.

Some confusion remains, however, since a recent phylogenetic study (Yang et al., 2012) considered Henicorhynchus to be valid, and members were not recovered in the same evolutionary lineage as Indian Gymnostomus species, suggesting that they are not closely related. It is unclear whether further taxonomic changes will be required in the future in order to reflect this disparity, but here on SF we currently follow Kottelat (2013) since it was published more recently and has been widely accepted, thus Henicorhynchus is a synonym of Gymnostomus.

Gymnostomus species are considered members of the tribe Labeonini within the putative cyprinid subfamily Cyprininae or simply the subfamily Labeoninae (name varies with author). According to the most recent phylogenetic research, this grouping is further divided into four subtribes; Labeoina, Garraina, Osteochilina, and Semilabeoina (Yang et al., 2012). Among these, Gymnostomus is included in the Labeoina alongside Labeo, Bangana sensu stricto (which includes the genus Nukta), Cirrhinus sensu stricto, Cirrhinus microlepis (which is of a different genetic lineage to other Cirrhinus species), and Incisilabeo. As noted above, however, this refers only to the Indian species of Gymnostomus, with the Southeast Asian species placed in the Osteochilina assemblage.

Some Gymnostomus species are common in mainstream rivers at certain times of year and extremely important in local fisheries during these periods.

References

1. Roberts, T. R., 1997 - Natural History Bulletin of the Siam Society 45(2): 171-203
   Systematic revision of the tropical Asian labeoin cyprinid fish genus Cirrhinus, with descriptions of new species and biological observations on C. lobatus.
2. Kottelat, M., 2013 - Raffles Bulletin of Zoology Supplement 27: 1-663
   The fishes of the inland waters of southeast Asia: a catalogue and core bibiography of the fishes known to occur in freshwaters, mangroves and estuaries.
3. Kottelat, M., 2003 - Raffles Bulletin of Zoology 51(2): 399-401
   Nomenclatural status of Crossocheilus burmanicus, C. horai and C. multirastellatus (Osteichthyes: Cyprinidae).
4. Kottelat, M., 2001 - WHT Publications, Colombo: 1-198
   Fishes of Laos.
5. Yang, L., M. Arunachalam, T. Sado, B. A. Levin, A. S. Golubtsov, J. Freyhof, J. P. Friel, W-J. Chen, M. V. Hirt, R. Manickam, M. K. Agnew, A. M. Simons, K. Saitoh, M. Miya, R. L. Mayden, and S. He, 2012 - Molecular Phylogenetics and Evolution 65(2): 362-379
   Molecular phylogeny of the cyprinid tribe Labeonini (Teleostei: Cypriniformes).