Species account

Description
The following account is a summary of the original description by Stuart et al., (2010).  Moderately stout salamander. Head broader than body, longer than wide, slightly sloping in profile. Snout short, truncate in dorsal view, rounded in profile, exceeding beyond lower jaw. Nostrils close to snout tip. Vomeropalatine teeth in two rows, anteriorly in contact and beginning posterior to the anterior margin of the choanae, converging into two parallel rows briefly, then diverging from one another. Glandular ridge on midline of crown from above anterior edge of eye to middle of head. Glandular ridge on outer margin of crown from above eye to base of paratoid. Paratoids enlarged, projecting backward. Glandular patch on skin of nape. Distinct vertebral tubercular ridge from posterior end of crown to base of tail, separated from ridge on midline of crown. Dorsolateral row of approximately 14 large glandular warts (rib nodules) on each side from level of axilla to base of tail, distinctly knob-like anteriorly, becoming smaller posteriorly, merging at level of groin. Smaller, glandular warts on most of remaining dorsal and ventral surfaces, warts on crown, nape, and back with clusters of sometimes conical glands; those on throat granular and widely spaced, those on belly arranged in striations perpendicular to body axis, with a smooth, glandular, ovoid patch of skin on chest. Gular fold weak. Four fingers, five toes, all without webbing. Tail a little shorter than snout-vent length, laterally compressed, with narrow dorsal fin, smooth ventral ridge, tip acuminate in profile. 

Colour of dorsal and ventral surfaces dark brown. Margin of upper and lower lip, posterior end of paratoid, rib nodules, dorsal margin of tail, outer margin of upper surface of hand and finger tips, lower surface of hand, except centre of palm, dorsal surface of toe tips, ventral surface of toes and extending from fifth toe to base of foot, cloacal region continuing to ventral ridge of tail bright orange. Anterior surface of forelimb from axilla to base of first finger with narrow, broken, yellow stripe. Anterior and ventral surfaces of hindlimbs with small, scattered yellow spots. Iris dark brown, pupil black. Animals on land are almost black, and darker than the animal caught in water.  

Total length 10-14 cm. 

Diagnosis
Tylototriton with broad, flattened head and truncated snout. It has a combination of distinct, knob-like rib nodules; glandular warts on most of remaining dorsal and ventral surfaces; very dark brown to black colouration on dorsum and venter and bright orange colouration on rib nodules and posterior end of paratoid. Differs from all other species in the T. asperrimus group by having bright orange colouration on the posterior end of paratoids.  

Eggs and larvae
Eggs have not yet been described. Two size classes of larvae were obtained in May, living in syntopy with the holotype, one specimen of 33.1 mm length, larvae in the other group measuring 17.9-20.9 mm.   

Distribution
The species is currently known only from the type locality: Nakai-Nam Theun National Protected Area, Boualapha District, Khammouan Province, Laos. 

Habitat
Tylototriton notialis occurs in evergreen mixed with deciduous and pine forest at approximately 1,000 m altitude. The holotype and larvae were found in a 3 m wide stream with slow current and sand and bedrock substrate, including leaf litter-filled potholes, just upstream from a 3 m high chute over bedrock. Water temperature 19.5° C. Two paratypes were found on land. 

Behaviour
The animals apparently enter the stream for reproduction. Other data are not available. 

Threats and conservation
No information available to date.  

Observations in captivity
No information available.  

Comments
Both genetically and morphologically T. notialis is distinctive among members of the T. asperrimus group. It is nested in a clade containing T. hainanensis from Hainan and Tylototriton species from Cao Bang, Vietnam (Stuart et al., 2010).  

 
Tylototriton notialis ventral view holotype
© 2007 Bryan Stuart

 
Range of Tylototriton notialis © 2011 W. Beukema & M. Sparreboom