Oreoglanis

Oreoglanis
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Siluriformes
Family:	Sisoridae
Subfamily:	Glyptosterninae
Tribe:	Glyptosternina
Genus:	Oreoglanis Smith, 1933
Type species
Oreoglanis siamensis Smith, 1933
Species
O. colurus[1] O. delacouri O. frenatus O. heteropogon[1] O. hypsiurus O. immaculatus[2] O. infulatus O. insignis O. jingdongensis[2] O. laciniosus[1] O. lepturus O. macronemus[3] O. macropterus O. majusculus[4] O. nakasathiani[1] O. setiger O. siamensis O. sudarai[1] O. suraswadii[1] O. tenuicauda[1] O. vicinus[1]

Oreoglanis is a genus of catfishes (order Siluriformes) of the family Sisoridae.

Taxonomy

The taxonomy of this group is currently under discussion and changes seem inevitable as the group is suspected to be non-monophyletic.^[3]

Based on morphology, Oreoglanis has been divided into two species groups. According to the original description of these groups, the O. siamensis species group is distinguished by having an emarginate caudal fin, and a lower lip notched medially with an entire or weakly laciniate posterior margin, while the O. delacouri species group is distinguished by having a lunate caudal fin (sometimes with strap-like extensions of the simple principal caudal rays), and a lower lip without a median notch with prominent extensions along the posterior margin.^[3] It has been suggested that only the marginal morphology of lower lip can be employed to recognize the two species groups.^[2] The O. siamensis group includes O. insignis, O. macropterus, O. setiger and O. siamensis, as well as the newer species O. immaculatus and O. jingdongensis based on the Chinese distribution of all members of this group. The O. delacouri group consists of O. delacouri, O. frenatus, O. infulatus, O. lepturus, O. macronemus and O. hypsiurus.^[2][3]

Distribution

These fish live in fast-flowing streams in China, mainland Southeast Asia and the Indian subcontinent.^[3] They are mainly distributed in the Mekong, upper Salween, and Irrawaddy River drainages.^[2] They range from the Irrawaddy drainage of Burma east to the Lam River drainage in central Vietnam.^[5]

Description

They are easily distinguished from other catfishes by their strongly depressed head and body, and greatly enlarged paired fins that have been modified to form an adhesive apparatus.^[3] The flattened shape of these fish and the large pectoral and pelvic fins provide essential adhesion in the fast-flowing waters they live in.

Members of this genus are distinguished by the combined presence of a continuous groove behind the lip (post-labial groove), the gill openings not extending onto the underside (venter), homodont dentition in upper jaw pointed, in two patches, joined into a continuous band, heterodont dentition in the lower jaw characterized by an inner row of pointed teeth and outer row of short, spatulate (shovel-like) teeth, and 16–18 branched pectoral rays.^[5] The head and body are moderately broad and strongly depressed. The skin is smooth dorsally. The eyes are minute, dorsolateral, and under the skin (subcutaneous). The lips are thin and papillated. Teeth in upper jaw are pointed and in large broad band with a small median indentation and rounded sides.^[5]

References

1. ^ ^{a b c d e f g h} Vidthayanon, C., Saenjundaeng, P., and Ng, H. H. (2009). "Eight new species of the torrent catfish genus Oreoglanis (Teleostei: Sisoridae) from Thailand". Ichthyological Exploration of Freshwaters. 20(2): 127-156. http://www.pfeil-verlag.de/04biol/pdf/ief20_2_04.pdf
2. ^ ^{a b c d e} DePing, Kong; Chen XiaoYong; Yang JunXing (2007). "Two new species of the sisorid Genus Oreoglanis Smith from Yunnan, China (Teleostei: Sisoridae)". Environmental Biology of Fishes 78 (3): 223–230. doi:10.1007/s10641-006-0040-2. 
3. ^ ^{a b c d e f} Ng, Heok Hee (2004). "Oreoglanis macronemus, a new species of glyptosternine catfish (Teleostei: Siluriformes: Sisoridae) from northern Laos" (PDF). The Raffles Bulletin of Zoology 52: 209–213. http://rmbr.nus.edu.sg/rbz/biblio/52/52rbz209-213.pdf. 
4. ^ Linthoingambi, I.; W. Vishwanath (2011). "Oreoglanis majusculus, a new glyptosternine catfish from Arunachal Pradesh, India (Teleostei: Sisoridae)". Zootaxa 2754: 60–66. http://www.mapress.com/zootaxa/2011/f/z02754p066f.pdf. 
5. ^ ^{a b c} Thomson, Alfred W.; Page, Lawrence M. (2006). "Genera of the Asian Catfish Families Sisoridae and Erethistidae (Teleostei: Siluriformes)" (PDF). Zootaxa 1345: 1–96. http://www.mapress.com/zootaxa/2006f/zt01345p096.pdf.