Laos Warty Newt; Laotriton de Laos
© 2011 Paul Bachhausen (1 of 23)
Due to its broad skull with angular oriented maxillaries, morphological charactristics of the skeleton, hyoid apparatus of warty newts, and twelve trunk vertebrae, this species was initially allocated to the genus Paramesotriton. However further work demonstrated it was different enough to be in its own genus (Dubois & Rafaelli 2009; Frost 2011). The tan coloration of back stripes, warts, and glands help distinguish Laotriton Laoensis from all other Paramesotriton. It is slightly more difficult to distinguish from P. fuzhongensis physically but regionally P. fuzhongensis is found in China; L. laoensis is exclusive to a small geographic region of about 4,800 km2 in Laos (see “Distribution and Habitat”). What makes Laotriton laoensis distinguishable from all other Asian salamandrides except Pachytriton is its reduced tongue pad lacking a free posterior margin. Even though Laotriton laoensis shares similar tongue characteristics with Pachytriton, the latter has a narrow skull with maxillaries oriented parallel to the body axis rather than oriented angular to the body axis. Concerning other Asian salamandrid genera, Cynops has thirteen trunk vertebrae, Echinotriton possesses a side row of large warts supported by rib tips, and lastly, Tylototriton has a uniformly pigmented venter and 13 - 15 trunk vertebrae, making them distinguishable from Laotriton laoensis and its 12 trunk vertebrae (Stuart and Pappenuss 2002).
Color in life is composed of an entire black body with tan tubercular dorsal ridges and parotoid glands. A spot on the back of the snout, dorsum of forelegs at junction with body, and some region extending obliquely from the back corner of the eye near the corner of the mouth are also tan. A very distinctive trait is the large irregular orange-red spots on the underside, chin, underside of axillae, and cloaca. Smaller similar spots are also present interspersed on venter and on underside of the tail base. Coloration in preservative tends to fade the tan dorsal stripes to yellow or white; back orange-red also fades to yellow or white (Stuart and Papenfuss 2002).
Males are slightly larger in almost every physical aspect: snout vent length, head length, head width, interocular distance, distance between anterior corner of the right eye to right nostril, internostril distance, distance between axillae on right side, right anterior limb length, right posterior limb length. Females tend to have larger tail lengths, tail depth, and total length. Other variations overall consists of the width of dorsal tan stripes, in some cases even merging to cover nearly the entire backside. Ventral spots also vary in shape and arrangement (Stuart and Papenfuss 2002).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Lao People's Democratic Republic
Life History, Abundance, Activity, and Special Behaviors
Trends and Threats
Relation to Humans
Possible reasons for amphibian decline
Intentional mortality (over-harvesting, pet trade or collecting)
Dubois, A., Raffaelli, J. (2009). ''A new ergotaxonomy of the family Salamandridae Goldfuss, 1820 (Amphibia, Urodela).'' Alytes, (26), (1–4) (1–85).
Gu, X., Wang, H., Chen, R., Tian, Y., Li, S. (2012). ''The phylogenetic relationships of Paramesotriton (Caudata: Salamandridae) based on partial mitochondrial DNA gene sequences.'' Zootaxa, (3150), 59-68.
Phimmachak, S., Stuart, B.L., Sivongxay, N. (2012). ''Distribution, Natural History, and Conservation of the Lao Newt (Laotriton laoensis) (Caudata: Salamandridae).'' Journal of Herpetology, 46(1), 120-128.
Stuart, B.L., Papenfuss, T.J. (2002). ''A new Salamander of the Genus Paramesotriton (Caudata: Salamandridae) from Laos.'' Journal of Herpetology, 36(2), 145-148.
Stuart, B.L., Rhodin, A.G.J., Grismer, L.L., Hansel, T. (2006). ''Scientific description can imperil species.'' Science (Washington D C), 312(5777), 1137.
Written by Jose Martin Jacuinde (jose.jacuinde AT berkeley.edu), University of California, Berkeley
First submitted 2013-11-25
Edited by Ann T. Chang (2014-03-05)
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