Species Description: Nussbaum, R. A., Brodie, Jr., E. D., Yang, D. 1995. A Taxonomic Review of Tylototriton verrucosus Anderson (Amphibia: Caudata: Salamandridae). Herpetologica, 51(3): pp. 257-268.
© 1996 Henk Wallays (1 of 58)
Author: Axel Hernandez
Tylototriton shanjing NUSSBAUM, BRODIE, & YANG 1995
Diagnosis and taxonomyThe holotype (KIZ II 0731 V.27) is an adult female collected at 2,150 m elevation at Dingpa in Jingdong County, Yunnan Province, China, in May of 1975, together with five paratypes. The specific epithet shanjing is derived from the Mandarin words shan for “mountain” and jing for “spirit”. The validity of this taxon has recently been disputed (HERNANDEZ 2016b). Considered a synonym of T. verrucosus by some authors on the basis of similarities in Cyt b (ZHANG et al. 2007; only a single sample of T. verrucosus from China was analyzed, however) or a subspecies of T. verrucosus by others (YANG & RAO 2008), its status requires further investigation. It is in any case very close to T. verrucosus in both its morphological and molecular characters. A recent study clarified the origin of the Yunnan populations (YU et al. 2013) within the supraspecies verrucosus and demonstrated that the diversification of four lineages that now occupy four different ecological niches in China would have started there about 800,000 years ago as a result of the collision of the Indian subcontinent with the central Chinese Yunnan-Guizhou Plateau and northern Indochina (Thailand, Laos, and Vietnam), and Pleistocene glaciations. Furthermore, T. shanjing occurs in parapatry with T. verrucosus in western Yunnan Province (NUSSBAUM et al. 1995, PHIMMACHAK et al. 1995), which further complicates the taxonomy of these taxa. Other phylogenies place T. shanjing within a clade comprising topotypic T. verrucosus, an unnamed population from Sagaing (Myanmar), two types from China, T. pulcherrimus, and T. podichthys (YUAN et al. 2011, LE et al. 2015, PHIMMACHAK et al. 2015, KHATIWADA et al. 2015, HERNANDEZ 2016b).
Concerning its morphology, T. shanjing is a robust crocodile newt. Females can reach up to 15.0 and males 17.0 cm in total length (FEI et al. 2012). This species has a coarse skin, a compressed tail, and a flat angular head. The dorsal background coloration is dark brown to black, and the bony edges of the head, vertebral ridge, dorsolateral glandular warts, limbs, tail and ventral parts are yellowish orange to bright yellow. The rear end of the cloaca forms a hole in females, in contrast to males, which have a slit instead. Sexual dimorphism is otherwise poorly expressed and varies between populations (NUSSBAUM et al. 1995). In general, males have slightly longer tails and less massive bodies.
According to my field surveys and molecular analysis, the main group of T. shanjing is native to central western Yunnan Province, including the type locality Dingpa in Jingdong County up to Longling in the west, Wubulu in the east, and Dayao in the north. A second group is found at high elevations in the northern mountain ranges of Yunnan Province from Dali to Lijiang, and a third group in the extreme south of Yunnan Province, from Xishuangbanna (including the locality Menghai) to Mojiang. The latter group has diverged only recently and lives in parapatry with T. pulcherrimus in the Wubulu/Zhangba area. Another study revealed that two well-differentiated morphotypes of T. shanjing existed in Mojiang and Tengchong Counties, respectively. These two types were recognized and separated morphologically by NUSSBAUM et al. (1995) and HU et al. (2013): T. shanjing from Tengchong has an overall dull and dark color, grows fairly large (15.18 cm on average), and has a longer tail and more distinct dorsolateral glandular warts than T. shanjing from Mojiang, which is smaller on average (13.32 cm) and saffron-yellow. The Tengchong type looks similar to topotypic T. verrucosus and this alone highlights the taxonomic problems mentioned above. Finally, the bony edges of the head are well developed in some southern populations and the color pattern is very variable. Another large type has been reported from Baoshan (KHATIWADA et al. 2015) where T. verrucosus occurs in parapatry, which could be interpreted as an instance of genetic introgression of the orange-patterned type (identified as T. shanjing by NUSSBAUM et al. 1995) into some populations of the brown- patterned morph (T. verrucosus). In the northwestern regions of Yunnan Province, two color morphs identified as T. shanjing and T. verrucosus coexist along the Gaoligongshan range (pers. obs.). All this underscores that detailed genetic analyses of these populations are needed to clarify the delimitation between the two species and their taxonomic statuses.
DistributionThe type locality is Dingpa, Jingdong County, Yunnan Province, China. Other localities are scattered from central western to northern and southern Yunnan (NUSSBAUM et al. 1995), but some of these localities might actually refer to T. verrucosus in the western areas of Tengchong and Longling; Baoshan; Yongde; Menglian; Jinghong-Menghai (Xishuangbanna); Jianshui; Xinping (Yuxi); Wubulu-Mojiang; Shuangbai; and Dali-Lijiang.
Habitat, ethology and ecologyThis species occurs from 950 to 2,500 m a.s.l., mostly between 1,500 and 1,650 m a.s.l. (pers. obs.), in mosaic mountain landscapes made up of rice paddies, irrigation canals for agriculture, and patches of forest. It is a nocturnal and terrestrial species found generally along irrigation canals and ponds. It becomes diurnal as its congeners during the mating season. Many populations were observed in close neighbourhood at moist, shady and forested sites in Xishuangbanna and Menglian, southern Yunnan Province. Small and large ponds were used as spawning sites covered by dense grasses and mixed deciduous forests. In July 2015, air temperature recorded during the daytime was 27.8 °C, that of the water 23.5 °C, and humidity 78 % at Menghai site in Xishuangbanna. Adults were seen near human cultures water points.
ReproductionIn its natural habitat in Yunnan, this species breeds in ponds, ditches and sometimes in artificial water bodies from May through August (pers. obs.). Mating dances usually take place in the water, but may sometimes commence on land. The male will take to the water first, with the female following soon. The cloaca of the male becomes more prominent at this time. A female ready to breed will respond to the pheromones released by the male, attract him with her movements, making him follow her, letting him stop her by positioning himself before her, and conducting a face-to-face roundabout dance. This procedure is repeated several times near the water and/or in flooded parts of a few centimeters deep until the male will deposit a spermatophore on bark or damp moss on the bank for the female to slide over and pick it up with her cloaca for fertilizing her eggs. The eggs are eventually laid in shallow water or on the wet bank in clutches of 30 to 80. The adults do not appear to consume the eggs. The latter are rather large at 2.5 mm, and have a gelatinous matrix that will often make them stick together. About 50% of them will not be fertilized or become infected by mould before they hatch. The larvae hatch after 15 to 30 days at water temperatures of 20.0 - 21.0 °C, measuring 12 - 15 mm, and metamorphosis takes place after 3 - 4 months. Sexual maturity is reached after 2.5 to 3 years (pers. obs.). Due to its strongly developed gills, the larva of T. shanjing can be assigned to the so-called Pond type (BOULENGER 1920, SPARREBOOM 1999, GROSSE 2007, ZIEGLER et al. 2008). This adaptation to low oxygen concentrations in the spawing sites is similar as its congeners. The larva shows a dorsal pigmentation irregular resulting in dark flecks on the yellow ground colour; the ventral side lacks any pigmentation. The tail has a well developed dorsal and ventral fin margin.
The Emperor crocodile newt’s reproductive ecology was studied in the Ailao Mts. in Xinping County in Yunnan from 2007 through 2010 by LI et al. (2012), demonstrating that it breeds in rice paddies and moist ditches near cultivated lands (mainly Poaceae, Polygonaceae and Chenopodiaceae) between 1,850 and 2,000 m. The sex ratio of breeding individuals changed over the reproductive season with more males being present during the earlier and later stages and more females in the middle period. Courtship took place mainly in the shaded moist ditches, but could continue and would culminate in mating in lentic water. Females deposited their eggs one to two days after mating, with a clutch comprising 126 ± 18 eggs in 22 instances observed. The process took 2 ± 2.7 hours with intervals of 1 - 3 minutes between each egg. The breeding season lasted from early May through late June. While the females laid their eggs into water 4 to 10 cm deep at the terraced embankments of rice paddies at the very beginning of the breeding season, they would select grassy seepages for this purpose after the middle of May.
Status, threats and conservationCommon in the past, the populations of T. shanjing have shrunk considerably in recent years. This trend is attributable for the largest part to deforestation and habitat destruction resulting from the expansion of cities in Yunnan, farming of carp in ponds that would otherwise make for suitable spawning sites, mass exports of specimens for the terrarium trade (1990 - 2000), and overexploitation for Chinese medicine and food. A protection zone is presently discussed in the area of Mt. Ailao in Xinping (Yunnan) where the species has become very rare (LI et al. 2010). It is classified as “Near Threatened” by the IUCN, but some populations actually face an immediate risk of becoming extinct.
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Citation: AmphibiaWeb. 2019. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 May 2019.
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