Jiangxi giant salamander

conservation

Conservation: Our long-term field monitoring of A. jiangxiensis sp. nov. yielded only a single incident of a breeding, wild population in the protected area at Daqi Mountain, Jing’an County. This protected area has a riverine habitat of only 6.50 km in linear distance and 36.0 km 2 of area. The upstream water runs inconstantly throughout the year, as flash floods occur occasionally in summer and droughts often occur in the winter, which lead to frequent habitat fragmentations. The downstream habitat out of the nature reserve is blocked by a dam and is inhabitable to A. jiangxiensis sp. nov. due to anthropogenic activities. This small, isolated, and sometimes fragmented population is particularly vulnerable to environmental changes, and thus the species faces a great extinction threat. Therefore, following the IUCN criteria B 1 (extent of occurrence less than 100 km 2, known to exist at only a single location, and extreme fluctuation of extent of occurrence) (IUCN, 2012), we recommend to classify A. jiangxiensis sp. nov. as Critically Endangered (CR), and we recommend to list the species as Class II protected in China, and to implement further assessments.

Discovery of a wild, genetically pure Chinese giant salamander creates new conservation opportunities.

description

Description of holotype: Adult male, body size relatively small, SVL 381 mm, TTL 589 mm; tail muscular, thick at base, gradually flattening posteriorly and distally; dorsal fin well developed, ventral fin much reduced, maximum tail height 76.2 mm; tail short, TAL 208 mm, TAL 54.6 % SVL, 35.3 % TTL. Head dorsally compressed, wide, HL 102 % HW; snout truncated, blunt, widen gradually posteriorly, projecting beyond lower jaw in ventral view; jaw muscular, distinctively widen from snout; jaw muscles continuous with two ovoid, convex temporal muscles dorsally posterior to each eye; nostrils small, NL 1.5 mm, anteriorly and laterally positioned, eye – nare distance 27.6 mm. Eyes small, rounded, EL 4.2 mm, 2.8 times NL, protuberant in life, lacking eyelids; dorsolaterally positioned, wide apart, IND 31.6 % IOD, EL 44.2 % SOD. Mouth large, corner almost reaching mid temporal protuberances; supralabial fold distinct; extending from posterior edge of mouth to axillary. Skin of head and lower jaw mostly smooth with small tubercles scattered dorsolaterally on temporal head and neck in life, all distributed irregularly, gradually increasing in numbers posteriorly; tubercles indistinct after pre

Discovery of a wild, genetically pure Chinese giant salamander creates new conservation opportunities.

diagnosis

Diagnosis: Andrias jiangxiensis sp. nov. can be distinguished from its congeners by a combination of the following characters: (1) head length almost equal to width; (2) head and lower jaw relatively smooth, with small tubercles arranged irregularly; (3) lateral neck fold discontinuous with body fold at forelimb insertion; (4) finger III distinctly longer than finger I; and (5) dorsum red-brown or yellow-brown in life, with large, irregular black patches. Comparisons: Andrias jiangxiensis sp. nov. can be distinguished from A. japonicus (Temminck, 1836) by having smoother head with indistinct tubercles (vs. dense, distinct, large tubercles). Considering that no population has been genetically identified as both pure A. davidianus and A. sligoi, and that farm-bred individuals exhibit genetic contamination (Yan et al., 2018), to avoid confusion due to translocated animals or hybrids, morphological comparisons are constrained to holotypes only. Specifically, Andrias jiangxiensis sp. nov. differs from A. davidianus (holotype MNHN-RA- 0.7613, images posted on: http: // coldb. mnhn. fr / catalognumber / mnhn / ra / 0.7613) by having a smooth head and lower jaw with indistinct, small, irre

Discovery of a wild, genetically pure Chinese giant salamander creates new conservation opportunities.

discussion

During the field surveys from September 2020 to March 2022, over 291 wild individuals of adults and juveniles were found in medium-sized, pristine mountain streams with 8 – 10 m wide, water depth 0.1 – 1.5 m, and with rocky substrate (Figure 7 A, B). Many natural caves formed by fallen wood, tree roots and cracks among rocks on both sides of streams provide hiding places for the new species. As a nocturnal species, A. jiangxiensis sp. nov. forages at night. Dorsal color patterning makes it blend well with the rocks at the bottom of the stream, making it difficult to find in flowing water. Vomit and excrement analyses of five wild individuals in July 2021 revealed fish, frogs, aquatic insects, and crustaceans in the natural diet. Two breeding caves were found in a backwater bay of the stream in January 2021 (Figure 7 C, D) and January 2022. A large number of larvae gathered at the entrance, emerging most likely two months after hatching (Figure 7 C, D). Larvae sightings peaked in February and exceeded 100 individuals per day. This continued until March, when no more new larvae emerged from the cave, and the larvae outside began to scatter throughout the stream. Combined with a quest

Discovery of a wild, genetically pure Chinese giant salamander creates new conservation opportunities.