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| Rhyacoschistura larreci
Kottelat, 2019
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Abstract
Rhyacoschistura, new genus, belongs to a group of genera (Physoschistura, Mustura, Pteronemacheilus, Petruichthys) characterised by the modified branched pectoral-fin rays of males, with a very thick first ray, usually without membranes between some of the branches and/or rays, and anterior rays and/or membranes covered by small tubercles at maturity. Rhyacoschistura is distinguished from them by the combination of: presence of a suborbital flap; emarginate caudal fin; lower lip with a wide median interruption and connected to isthmus by a frenum; body depth about equal from behind head to caudal-fin base. Rhyacoschistura larreci, new species, is described from the Mekong drainage in Xayaburi Province, Laos. It is distinguished by details of the morphology of the pelvic fin, and its colour pattern (flank with numerous narrow slanted bars, very irregularly organised and shaped, more or less connected, or sometimes covering the whole flank). Schistura suber, from Nam Ngum watershed, is redescribed on the basis of adults and placed in Rhyacoschistura.
Keywords: Pisces, Schistura, Mustura, Physoschistura
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| Figure 4. Rhyacoschistura larreci, MHNG 2727.011, holotype, 57.1 mm SL; Laos: Xayaburi: Nam Houng watershed. Figure 5. Rhyacoschistura larreci, CMK 28037, paratype, 57.8 mm SL; Laos: Xayaburi: Nam Houng watershed; immediately after fixation. |
Rhyacoschistura, new genus
Type species. Rhyacoschistura larreci, new species.
Etymology. Rhyacoschistura is derived from the Greek word ῥύαξ, -κος (rhyax, meaning a rushing stream, a
torrent) and the genus name Schistura (itself based on σχιστός [schistos; divided] and οὐρά [oura; tail]). In reference
to the torrent and hill stream habitat of the species placed in the genus. Gender feminine.
Included species. Rhyacoschistura larreci and Rhyacoschistura suber (Kottelat, 2000).
Rhyacoschistura larreci, new species
Etymology. Named for LARReC, Living Aquatic Resources Research Center, Vientiane, for its 20th anniversary, and appreciation to several of its staff for 20 years of collaboration in the field. Treated as a masculine noun in
genitive, indeclinable.
Maurice Kottelat. 2019. Rhyacoschistura larreci, A New Genus and Species of Loach from Laos and Redescription of R. suber (Teleostei: Nemacheilidae). Zootaxa. 4612(2); 151–170. DOI: 10.11646/zootaxa.4612.2.1
Rhyacoschistura larreci, a new genus and species of loach from Laos and redescription of R. suber (Teleostei: Nemacheilidae) phakhaolao.la/en/publications/rhyacoschistura-larreci-new-genus-and-species-loach-laos-and-redescription-r-suber
