Description
Tylototriton panhai is a medium sized Tylotriton with a stout body and a snout to posterior vent length that measures about 85.9 – 86.7 mm in females and 64.9 – 80.4 mm in males. Tylototriton panhai’s head is hexagonal, wider than long, and somewhat oblique in profile. Its short snout is truncate with a slight under-bite. Its nostrils are fairly close to its snout tip. On its head, the noticeable dorsolateral bony ridges protrude strongly. They are narrow, somewhat rough, and start above the eye and continue to above the anterior end of the parotoid. The ridge’s posterior end scrolls proximally. There is no middorsal ridge on the head. Tylototriton panhai does not have a labial fold. Its wide front-squamosal arch is robust, and its approximately 66 vomerine teeth form an inverted V-shape, which converges anteriorly but doesn’t reach the choana. The holotype has 80 teeth on its upper jaw and 81 on its lower jaw. Tylototriton panhai’s tongue is oval and is free laterally and posteriorly but attached to the mouth floor. The parotoid glands are large and project dorsolaterally and posteriorly. Tylototriton panhai has a gular fold but lacks costal folds. It has fine granules densely distributed on its dorsum but sparsely distributed on its throat. On its mid ventrum, the granules form transverse striations. Its has wide, moderate dorsolateral crests but lacks a middorsal crest. It has 14 trunk vertebrae, and its vertebral ridge is noticeable and smooth. Its rib nodules are large and readily discernible as knob-like warts with 14 protrusions on each side of the body from the axilla to the tail’s base. The size of the rib nodules increases slightly from the most anterior nodule until the fourth nodule then gradually decreases posteriorly. When its long limbs are adpressed along its body, the forelimbs and hindlimbs overlap noticeably. It lacks webbing on both its fingers and toes, and its tail compresses laterally with a smooth ventral edge and pointed tip. Posteriorly, the dorsal fin becomes more distinct (Nishikawa et al. 2013; Phimmachak et al. 2015).

Tylototriton panhai is a medium sized Tylotriton with rough skin, narrow, defined dorsolateral bony ridges on its head, long, thin limbs, and thin tail. There is a noticeable overlap of the limbs when they are adpressed. Its coloration is orange to reddish brown on its dorsal head, upper and lower lips, vertebral ridge, rib nodules, limbs, and vent region. Like other members of the genus Tylototriton, Tylototriton panhai has prominent dorsal warts, dorsolateral bony ridges on its head, protruding round warts lining its dorsolateral body, and no quadrate spine. Based on molecular phylogeny, Tylototriton panhai is a member of the subgenus Yaotriton. However, it differs from all other species of the subgenus due to its noticeable yellow to reddish brown markings on its head, trunk, and tail edges. Tylototriton panhai’s widely developed dorsolateral bony ridges on its head, black limbs, and tail distinguishes it from others in the Tylototriton genus. More specifically, T. panhai differs from T. daweishanensis due to its yellow to reddish brown markings on head, trunk, and tail edges. Tylototriton panhai’s isolated rib nodules distinguishes it from T. kweichowensis and T. taliangensis. The colorful anterior half of its head differs from T. kweichowensis and T. yangi. Its colored markings also differs from T. verrucosus verrucosus (Nishikawa et al. 2013).

In life, Tylototriton panhai has a dark brown to black dorsal ground coloration. Its venter is slightly lighter, and the anterior half of the head, parotoids, vertebral ridge, rib nodules, tips of digits, margin of vent slit, and ventral edges of its tail have markings that are yellow, orange, or reddish brown. These markings fade to a cream color in preservative, while the darker brown ground color fades to a lighter brown or orange (Nishikawa et al. 2013).

The coloration of markings in Tylototriton panhai often varies from yellow to dark orange to reddish brown. The size of rib nodules can also vary. Often, dark reddish brown markings characterize individuals from Phu Hin Rong Kla National Park in Phitsanulok Province, while nodules smaller than the holotype are typical of individuals from Phu Suan Sai National Park in Loei Province (Nishikawa et al. 2013).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Lao People's Democratic Republic, Thailand

View distribution map in BerkeleyMapper.

Tylototriton panhai can be found in Phu Hin Rong Kla National Park, Phitsanulok Province, and Phu Luang Wildlife Sanctuary and Phu Suan Sai National Park, Loei Province, Thailand. Phu Hin Rong Kla National Park is the southernmost locality of the genus, Tylototritoni (Nishikawa et al. 2013).

Tylototriton panhai thrives in humid forests with bamboo bushes and an assortment of bodies of water like temporal rain puddles and streams (Nishikawa et al. 2013).

Life History, Abundance, Activity, and Special Behaviors
Outside of breeding season, T. panhai is difficult to find and is likely terrestrial. Breeding season lasts from May to July, and during this time, adults resided in bodies of water. Eggs are attached to wet grass, plants overlooking water surfaces, under wood debris, or on land near small bodies of water. Eggs usually measure 1.5 – 2.7 mm and are dark cream in color with a dark brown animal pole. Clutch size is unknown (Nishikawa et al. 2013).

Comments
The species authority is: Nishikawa, K., Khonsue, W., Pomchote, P., Matsui, M. (2013). "Two new species of Tylototriton from Thailand (Amphibia: Urodela: Salamandridae).'' Zootaxa, 3737(3), 261 - 279.

The genus Tylototriton occurs exclusively in Northern Laos (>17degrees38’N) and at elevations greater than or equal to 980 m (Phimmachak et al. 2015).

Analysis of mt DNA revealed that Tylototriton is likely a monophyletic group with two major clades. One of the major clades consisted of the subgenus Yaotriton, which in turn contained two major subclades. Tylototriton panhai is grouped into one of these subclades along with T. vietnamesis, T. asperrimus, T. hainanensis, T. notialis, T. asperrimus (undetermined species identity), and T. ziegleri. Scientists recognize four species (T. panhai, T. notialis, T. anguliceps, and a fourth newly discovered, unnamed species of Tylototriton occurring in Laos (Pimmachack et al. 2015).

The species is named after Dr. Somsak Panha, a prominent Thai naturalist who assisted in field surveys of Tylototriton panhai.

References

Nishikawa, K., Khonsue, W., Pomchote, P., Matsui, M. (2013). ''Two new species of Tylototriton from Thailand (Amphibia: Urodela: Salamandridae).'' Zootaxa, 3737(3), 261 - 279. [link]

Phimmachak, S., Aowphol, A., Stuart, B.L. (2015). ''Morphological and molecular variation in Tylototriton (Caudata: Salamandridae) in Laos, with description of a new species.'' Zootaxa, 4006(2), 285-310.

Species Account Citation: AmphibiaWeb 2019 Tylototriton panhai: Panha’s Crocodile Newt <https://amphibiaweb.org/species/8094> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

AmphibiaWeb's policy on data use.