Tuesday, June 23, 2015

[Ichthyology • 2012] Metzia bounthobi • A New Species of Metzia (Cypriniformes: Cyprinidae) from Northern Laos


 Pa tep thob | Metzia bounthobi
Shibukawa, Phousavanh, Phongsa & Iwata, 2012
FIGURE 1. Freshly collected specimen of Meztia bounthobi (holotype, 57.0 mm SL, NIFI 4680), Mekong Basin in Sopvan, Nyoi District, Luang Prabang Province, Lao PDR (20°36.5’N, 102°39.1’E), 23 June 2010. Same specimen above and below but on different backgrounds to provide full view of characters of the species.

Abstract
A new cyprinid fish, Metzia bounthobi, is described on the basis of 18 specimens (including 10 specimens in type series) from the Mekong River basin in Phongsaly and Luang Prabang Provinces, northern Laos. The species is distinguished from congeners by having the following diagnostic traits: 18–20 branched anal-fin rays (vs. 10–18 in the others); 49–55 lateral-line scale rows (vs. 35–48); 33–36 predorsal scale rows (vs. 15–20); 20–22 circumpeduncular scale rows (vs. 14–18); 8–10 gill rakers on outer surface of first gill arch (vs. 12–18). The new species also resembles species of Hemiculterella, Ischikauia and at least some species of Anabarilius, in sharing a sharp keel developed only between the base of the pelvic fin and anus, soft last unbranched dorsal-fin ray, and air bladder composed of two chambers; however, M. bounthobi differs in having a considerably rounded snout (vs. pointed in Hemiculterella, Ischikauia and Anabarilius), 18–20 branched anal-fin rays (vs. 8–17 in Hemiculterella, Ischiakuia and Anabarilius), 49–55 lateral-line scale rows (vs. more than 58 in Ischikauia and Anabarilius, except for A. transmontana with 54–57), air bladder with rounded posterior end (vs. posterior end with a small lobe at least in Hemiculterella) and 39–40 vertebrae (vs. 40–43, 42–43 and 43–48 in Hemiculterella, Ischikauia and Anabarilius, respectively).

Key words: Cypriniformes, Cyprinidae, Metzia bounthobi, new species, Laos

FIGURE 1. Freshly collected specimen of Meztia bounthobi (holotype, 57.0 mm SL, NIFI 4680), Mekong Basin in Sopvan, Nyoi District, Luang Prabang Province, Lao PDR (20°36.5’N, 102°39.1’E), 23 June 2010. Same specimen above and below but on different backgrounds to provide full view of characters of the species.
FIGURE 4. Paralaubuca barroni, NUOL-P 4038, 75.4 mm SL, Nyoi District, Luang Prabang Province, Lao PDR. Photographed by T. Phommavong.

Distribution and habitat. Metzia bounthobi is hitherto known only from the Ou River basin (a tributary of the Mekong) in Phongsaly and Luang Prabang provinces of northern Laos. This species was found in upland clear streams with moderate or slow current.

 Etymology. The specific name, bounthobi, is in honour of Bounthob Praxaysombath (NUOL), who was the leading researcher performing the field surveys throughout the NUOL-NEF project on 2007–2010. Eight of all 10 type series of the new species were brought from the project surveys.


Shibukawa, Koichi, Phouvin Phousavanh, Koneuma Phongsa & Akihisa Iwata. 2012. A New Species of Metzia (Cypriniformes: Cyprinidae) from Northern Laos.
  Zootaxa. (3586): 264–271.

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