Pelodiscus huangshanensis, Gong & Peng & Huang & Lin & Huang & Xu & Yang & Nie, 2021

Gong, Yan-An, Peng, Li-Fang, Huang, Song, Lin, Yan-Feng, Huang, Ru-Yi, Xu, Yu-Hao, Yang, Dian-Cheng & Nie, Liu-Wang, 2021, A new species of the Genus Pelodiscus Fitzinger, 1835 (Testudines: Trionychidae) from Huangshan, Anhui, China, Zootaxa 5060 (1), pp. 137-145 : 140-143

Pelodiscus huangshanensis sp. nov. Gong, Peng, Huang & Nie, 2021

( Figs. 2–5 )

Suggested English name: Huangshan soft-shelled turtle

Suggested Chinese name: •山ƼÞ× (Huáng Shān Mǎ tí Biē)

Holotype. ANU20210001 , an adult male ( Fig. 2 ), was found in a stream from Xikou Town, Xiuning County, Huangshan City, Anhui Province, China (118.02°N, 29.69°E, and 170 m A. S. L.). The coordinates are given only with a precision of 0.01 degrees to avoid private or commercial sampling. The specimen was collected on 10 June 2017 and deposited at Anhui Normal University Museum (voucher: ANU20210001 ).

Paratypes. ANU20210002, adult female ( Fig 3 ); ANU20210003, adult female; ANU20210004, juvenile; ANU20210005, juvenile; CIB116368, juvenile; SNHM5414, juvenile. They were sampled from May to June, 2017 around the site of holotype.

Diagnosis. Pelodiscus huangshanensis sp. nov. differs from the five known congeners by a combination of the following characters: (1) Small size; maximum carapace length of 84.0 mm and maximum body length of 190 mm; (2) keel high; (3) tiny yellowish-white spots on the throat; (4) no black pinstripes around the eyes; (5) white longitudinal bands on both sides of the neck in juveniles, absent in adults ( Fig. 4 ); (6) plastron yellowish-white, and only a dark patch on each side of the armpit; (7) many tubercles on the dorsal surface, but indistinct in the center; and (8) entoplastron “⌒” shaped.

Description of holotype and Variation. Where they differ from the holotype, features of the paratypes are listed in parentheses (ANU20210002–5, CIB116368, SNHM5414). Holotype of an adult male (the first two are adult females and the last four are juveniles); carapace length 82.5 mm (adult females 73.4–84.0 mm, juvenile 40.5–55.9 mm); plastron length 79.3 mm (adult females 75.7–86.1 mm, juvenile 39.9–55.8 mm); body length 190.0 mm (adult females 144.9–160.0 mm, juvenile 88.2–114.7 mm) ( Table 3 ). Back and side of head have many fine dark brown to black spots; no black pinstripes around the eyes. The neck shows no white longitudinal striae bilaterally (there are white longitudinal bands on both sides of the neck in juveniles). The throat has many tiny yellowish-white spots. The carapace slightly oval with a high keel. The carapace is olive brown to dark brown. The dorsal surface has many tubercles, but it is indistinct in the center. The plastron yellowish-white, and only a dark patch on each side of the armpit. Entoplastron “⌒” shaped.

Ecological notes. On June 20, 2017, a female individual (raised in Xiuning Institute of Rare Aquatic Animals) laid five eggs with a postpartum weight of 134 g. The eggs are white, nearly spherical; average length 15.95 ± 0.11 (15.79–16.01) mm; average short diameter 15.6 ± 0.16 (15.56–15.89) mm; and average weight 2.12 ± 0.23 (1.84–2.4) g. Hatching occurs at natural temperatures after 60–65 days. The average weight of neonates was 1.30 ± 0.08 (1.20–1.40) g. Three months old horse-hoof soft-shelled turtles are shown in Fig. 5 .

Etymology. The specific name refers to the type locality of this species, Huangshan City, Anhui Province. We suggest the following common names: horse-hoof soft-shelled turtle in English and “Huáng Shān Mǎ tí Biē (•山ƼÞ×)” in Chinese. The native people of Huangshan have called it “Mǎ tí Biē (ƼÞ×)” for more than a thousand years.

Distribution. This species is currently known only from the type locality, Xiuning County, Huangshan City, Anhui Province, China.

Comparisons. Pelodiscus huangshanensis sp. nov. can be distinguished from P. axenaria by the following morphological characters: (1) Many tubercles on the dorsal surface, but indistinct in the center (vs. smooth carapace, no tubercles); (2) plastron yellowish-white, and only a dark patch on each side of the armpit (vs. a single dark-gray central figure enclosed by the hypoplastra and xiphiplastra); and (3) white longitudinal bands on both sides of the neck in juveniles, absent in adults (vs. absence of spots on the neck).

Pelodiscus huangshanensis sp. nov. can be further distinguished from P. sinensis by the following morphological characters: (1) Small size; maximum carapace length 115.6 mm (vs. medium size; maximum carapace length 230 mm); (2) plastron yellowish-white, and only a dark patch on each side of the armpit (vs. plastron yellowishwhite with many dark spots); (3) keel high (vs. keel low); (4) no black pinstripes around the eyes (vs. black pinstripes around the eyes); (5) the throat has many tiny yellowish-white spots (vs. large yellowish-white spots with dark edges); and (6) entoplastron “⌒” shaped (vs. entoplastron “˄” shaped).

Pelodiscus huangshanensis sp. nov. can be further distinguished from P. maackii by the following morphological characters: (1) Small size; maximum carapace length of 115.6 mm (vs. larger size; maximum carapace length more than 350 mm); (2) plastron yellowish-white, and only a dark patch on each side of the armpit (vs. plastron yellowish-white with no markings or relatively small, faint round to oval dark markings); (3) the throat has many tiny yellowish-white spots (vs. large yellowish-white spots with dark edges); (4) keel high (vs. keel low); and (5) no black stripes around the eyes (vs. black pinstripes around the eyes).

Pelodiscus huangshanensis sp. nov. can be further distinguished from P. parviformis by the following morphological characters: (1) Plastron yellowish-white, and only a dark patch on each side of the armpit (vs. plastron yellowish-white with no markings); (2) many tubercles on the dorsal surface, but indistinct in the center (vs. dorsal tubercles in longitudinal series more or less discrete; central tubercle in front of marginal ridge of carapace small); and (3) entoplastron “⌒” shaped (vs. entoplastron “˄” shaped).

Pelodiscus huangshanensis sp. nov. can be further distinguished from P. variegatus by the following morphological characters: (1) Many tubercles on the dorsal surface, but indistinct in the center (vs. dorsal surface roughened by longitudinal ridging and smaller protuberances spread over the leathery margin); (2) plastron yellowish-white, and only a dark patch on each side of the armpit (vs. plastron pinkish white to pale reddish orange distinct, large dark blotches, underside of leathery margin of carapace pigmented); (3) no black pinstripes around the eyes (vs. black pinstripes around the eyes); and (4) the throat has many tiny yellowish-white spots (vs. large yellowish-white spots with dark edges).

Figures

FIGURE 2. Dorsal and ventral aspects of the holotype of Pelodiscus huangshanensis sp. nov. (ANU20210001, adult male)

FIGURE 3. Dorsal and ventral aspects of the paratypes of Pelodiscus huangshanensis sp. nov. (ANU20210002, adult female)

FIGURE 4. Head and neck of Pelodiscus huangshanensis sp. nov.; A, B ANU20210001, male; C, D ANU20210004, juvenile.

FIGURE 5. The three months old Huangshan soft-shelled turtles.