This species is currently known only from 600–1,900 m Asl in parts of Viet Nam north of Hanoi (Orlov et al. 2002, Swan and O'Reilly 2004, Nguyen et al. 2009a, Nguyen et al. 2009b, Sparreboom 2014, J. Rowley unpubl. data). These may not represent the actual limits of the species' range as similar habitat and elevations to those in the species' known localities extend into southern China. Further surveys there may uncover its presence, therefore its range has been projected beyond known sites to include these areas of suitable habitat. The species' EOO is 80,578 km2, which represents two threat-defined locations.
Habitat and Ecology
This predominantly aquatic species is associated with streams in closed-canopy, mostly evergreen forest (Swan and O'Reilly 2004, Stuart et al. 2008, Sparreboom 2014). There have also been some observations of the species in severely disturbed environments including polluted streams and artificial pools (Sparreboom 2014, Jodi Rowley unpubl. data). It is generally nocturnal and remains active throughout the year, having no hibernation or aestivation period (Sparreboom 2014). It reproduces by larval development and breeding occurs in small pools within streams (Stuart et al. 2008, Sparreboom 2014). The breeding season commences in November, during which time males aggressively defend territories against other males as well as certain females (Sparreboom 2014). Oviposition in this species has been observed from January to April, and involves the female folding the leaves around the adhesive eggs with her hind legs (Sparreboom 2014).
This species' overall abundance is not well known, however it has been detected in a number of surveys (Bourret 1942, Orlov et al. 2002, Swan and O'Reilly 2004, Nguyen et al. 2009a, Nguyen et al. 2009b, Sparreboom 2014, J. Rowley unpubl. data). It is likely that ongoing forest loss associated with agriculture, logging (Swan and O'Reilly 2004, Sodhi et al. 2009), collection for trade, and water pollution (Swan and O’Reilly 2004, Sparreboom 2014) are causing some population declines.
Habitat loss due to expanding agriculture has been identified as a major threat to biodiversity throughout Southeast Asia and is ongoing in Viet Nam (Sodhi et al. 2009). Habitat in some of this species' localities (e.g. Van Ban, Lao Cai Province) is severely threatened by the selective logging of large, valuable timber species, unsustainable harvest of non-timber forest products (e.g. bamboo, fungi, medicinal plants, and rattan), the clearance of large tracts of riparian forest (often by fire) for the cultivation of cardamom, degradation by continued grazing of domesticated buffalo (Swan and O’Reilly 2004), and slash and burn agriculture (J. Rowley pers. comm. January 2016). Throughout its range the pollution of waterways with fishing line and nets is also known to affects this species (Sparreboom 2014, J. Rowley pers. obs. July 2015). It has been observed in streams within disturbed pasture and rice paddies as well as artificial pools, and is very likely threatened by habitat loss (Sparreboom 2014, J. Rowley unpubl. data). The species is also threatened by collection from the wild for use in traditional medicine and the pet trade (Swan and O’Reilly 2004, Sparreboom 2014).
This species is known from a number of protected areas including Tam Dao and Ba Be National Parks (Orlov et al. 2002, Stuart et al. 2004, Nguyen et al. 2009). Other protected areas are included in parts of this species' predicted range; it very likely occurs in many of these also. The species has been protected by Vietnamese law since 1992 (Sparreboom 2014).
It may also be necessary to explore options for the increased protection of this species' habitat and enforcement of laws that are in place for the prohibition of its collection from the wild.
In order to ensure the species' long-term survival, the lack of data must be addressed; research should be carried out to determine its true distribution, relative abundance, population trends, and the effects of its harvest.
Red List Status
Least Concern (LC)
Listed as Least Concern as this species is relatively widespread, with an extent of occurrence (EOO) of 80,578 km2.
IUCN SSC Amphibian Specialist Group 2017. Paramesotriton deloustali. The IUCN Red List of Threatened Species 2017: e.T16129A113959728. http://dx.doi.org/10.2305/IUCN.UK.2017-2.RLTS.T16129A113959728.en .Downloaded on 18 January 2019