Species account

Description
Robust, big newt. Head equal in width to body. Head strongly sloping in profile. Snout short, truncate, rounded in profile, and exceeding beyond lower jaw. Tongue small with tongue pad lacking a free posterior margin. Three tubercular dorsal ridges, one midline and two lateral, extending from top of head to base of tail. Dorsal and ventral surfaces largely covered with glands and warts. Paratoids enlarged, projecting backwards. Tail laterally compressed. Dorsal tail fin and indistinct ventral tail fin. Tail tip rounded (Stuart & Papenfuss, 2002). Striped pattern of blue-white spots in the tail of the male, especially prominent during the breeding season. The female develops a protruding cloaca during the breeding season (Bachhausen, 2008, 2009).

Colour black. Tubercular dorsal ridges and dorsum of paratoid glands tan. Tan spot on dorsum of snout, dorsum of fore legs at junction with body, and extending somewhat obliquely from posterior corner of eye to near corner of mouth. Large, irregular, orange-red spots on underside, orange-red on underside of tail base (Stuart & Papenfuss, 2002).

Total length 17-19 cm (Stuart & Papenfuss, 2002); larger sizes have been reported for captive animals, 19 cm (male) to 23 cm (female) (Bachhausen, 2008, 2009).

Diagnosis
Large newt with distinct tan dorsal stripes. Dorsal and ventral surfaces covered with glands and warts. Reduced tongue pad. Large, orange-red spots on ventral side.

Eggs and larvae
Eggs are attached singly, or mounted singly in rows between leaves of waterplants. In captive animals egg laying was recorded from mid November to end February, at water temp. of 16°C. One female laid 445 eggs (90% fertilized) in one year, 125 resp. 170 in the following years. Larvae hatch after five weeks at a size of approximately 14 mm when kept at a water temp. of 18-19° C. Metamorphosis takes place after approx. 3.5 months at a size of about 45 mm. One year old juveniles are approximately 10 cm (Bachhausen, 2008, 2009, 2011).

Distribution
Currently known only from the type locality, the Saysamboun Special Zone, as well as the Phoukhout District in Xiangkhouang Province in northern Laos, at 1,160 m altitude. It might occur more widely (IUCN, Conservation International, and NatureServe, 2006).

Habitat
The species is aquatic and was found in two streams in dry shrub-land. Taller scrub, grasses and banana trees line the streams. The streams are 1-2, resp. 2-4 m wide, with a substrate of silt, gravel, rocks, and submerged rock faces.
 

Behaviour
The animals are found in the pools within the streams, and are active during the day, at least in November (Stuart & Papenfuss, 2002). Captive animals were mostly active at dusk and at night. Courtship was observed from September to January at water temp. of 16°C. Courtship behaviour patterns resemble those described for Paramesotriton hongkongensis and other Paramesotriton species. The male takes up position in front of the female, bends his tail and makes fanning movements with the distal part of his tail in the direction of the female's snout. The male then turns round and creeps ahead of the female, which follows and regularly touches his undulating tail. The male may deposit one to five spermatophores. The female picks up the sperm with her cloaca. After sperm pick-up the male would bite the female, usually at the tail base but also in other parts of her body, and hold on to her for several minutes upto 30 minutes, while the female stayed more or less calm. Interestingly, and unlike what is seen in related species of Paramesotriton, no aggressive behaviour has been observed in this species thus far (Bachhausen, 2008, 2009, 2011).
 

Threats and conservation
Laotriton laoensis is harvested for medicine and food locally. Distribution data are lacking (IUCN, Conservation International, and NatureServe, 2006).


Observations in captivity
Animals were imported into Germany in 2005 by Thomas Schöttler (Bad Schwalbsch, Germany). The species has been bred in captivity until the second generation. Mating was observed from September to January at 16° C. Eggs were laid at temperatures between 15-18° C. Larvae and juveniles were raised successfully at temp. between 18-19° resp. 20-22°C. Aquariums were large and had running water. Water was changed frequently and tanks were cleaned meticulously (detailed accounts in Bachhausen, 2008, 2009, 2011).

Comments
None.

Laotriton laoensis
© François Maillet

 
© 2006 IUCN, Conservation International and NatureServe. (click on map to enlarge)