AmphibiaChina 中国两栖类.

Conservation Status (definitions)

IUCN Red List Status Account CITES No CITES Listing National Status None Regional Status None

Description
Raorchestes dulongensis is a small, stocky frog described from three adult male specimens, with a snout-vent length ranging from 15.0 - 19.0 mm. No female specimens were collected or described. The head is longer than it is wide. The snout extends slightly beyond the lower jaw and appears pointed from a dorsal view but rounded in profile. The nostrils are positioned closer to the anterior corner of the eyes than it is to the tip of the snout. The canthus rostralis is rounded. The loreal region is concave. The internarial distance is shorter than the interorbital distance. The eye has a diameter that is equivalent to the snout length and much larger than the tympanum. The upper eyelid is narrower than the interorbital distance. The oval pupil is horizontal. The tympanum is small but distinct, and there is a broad supratympanic fold present at the posterior corner of the eye that extends to the forearm. The top of the head is relatively flat. In the males, a singular vocal sac is present. The length of both the forelimbs and hands are longer than half of the body size, and the forelimb length is shorter than the hand length. In the adult males, the nuptial pad is absent. Both inner and outer metacarpal tubercles are present. From shortest to longest finger lengths, the order is: I < II < IV < III. The fingers have narrow, lateral dermal fringes; no webbing; and single, prominent subarticular tubercles. Supernumerary tubercles are absent. The tips expand into well-developed discs with distinct circummarginal grooves. The tibiotarsal articulation reaches the anterior area of the eye when the hind limb is adpressed along the body. The hind limbs are long with the tibia noticeably shorter than the thigh. When the hind limbs are held at right angles to the body, the heels slightly overlap. There is an oval-shaped inner metatarsal tubercle, but the outer metatarsal tubercle is absent. From shortest to longest toe lengths, the order is: I < II < V < III < IV. Like the fingers, the toes have narrow, lateral dermal fringes. Supernumerary tubercles are absent. Webbing on the toes is rudimentary, and there are single subarticular tubercles on toes I, II, III, and V, and two on toe IV. The tips of each toe have well-developed discs with circummarginal grooves (Wu et al. 2021).

DIAGNOSIS:

Other Raorchestes species found in the wider geographic area include R. andersoni, R. annandalii, R. cangyuanensis, R. gryllus, R. hillisi, R. longchuanensis, R. malipoensis, R. manipurensis, R. menglaensis, R. parvulus, R. rezakhani, R. sahai, and R. shillongensis. Raorchestes dulongensis is smaller than R. andersoni, R. gryllus, R. menglaensis, and R. sahai. The longer head length than width in R. dulongensis sets it apart from all of the other species in the area except, R. hillisi, with R. andersoni, R. annandalii, R. cangyuanensis, R. gryllus, R. malipoensis, R. manipurensis, R. parvulus, R. rezakhani, R. sahai, and R. shillongensis having longer widths and R. longchuanensis and R. menglaensis having about equal lengths and widths. A distinct tympanum in R. dulongensis distinguishes it from R. gryllus, R. menglaensis, and R. rezakhani. The lack of finger webbing in R. dulongensis differentiates it from R. gryllus and R. menglaensis. Lastly, rudimentary toe webbing in R. dulongensis sets it apart from R. andersoni, R. gryllus, R. hillisi, R. longchuanensis, R. malipoensis, R. manipurensis, R. parvulus, R. rezakhani, and R. sahai (Wu et al. 2021, Huang et al. 2023).

COLORATION:

In life, R. dulongensis is primarily brown. The irises are a golden brown. There is brown coloration dorsally on the head and back. There is a dark triangle-shaped marking between the eyes. There are two curved lines along the back but no mid-dorsal line. The dorsal sides of the limbs have dark brown crossbars. The brown flanks have a distinct black region located in between two white patches. The thigh has a similar black patch near the groin. The belly is a creamy-white color with many white spots ventrally. The finger and toe discs are grayish-orange (Wu et al. 2021).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: China

View distribution map in BerkeleyMapper.

All three R. dulongensis specimens were collected from one location near Qinlangdang Village in Derung-Nu Autonomous County Gongshan, Yunnan Province, China, along the Dulong River (Wu et al. 2021). This distribution occurs along the Gaoligong Mountain-Bilou Snow Mountain area (Shi et al. 2022). The habitat consists of sub-canopy. Specimens were collected at an elevation of 1218 m a.s.l. (Wu et al. 2021).

Life History, Abundance, Activity, and Special Behaviors
Specimens were found, concealed, in shrubs and herbs along the side of the road near the river at night. Members of the genus are noted for being nocturnal (Wu et al. 2021).

Males were heard calling at night. The calls varied in both overall duration and in inter-call duration and sounded like, “treenk…treenk…treenk…” (Wu et al. 2021).

Reproductive behavior was not observed in the collected specimens. However, in captivity, the closely related species R. longchuanensis was observed to lay two clutches of 10 - 12 eggs each, and the eggs hatched after 25 - 30 days (Yan et al. 2021).

Sympatric anuran species include Zhangixalus burmanus and Duttaphrynus cyphosus (Wu et al. 2021).

Larva
Specific larval information for R. dulongensis is unknown as of 2023. However, its other members of the genus are direct developing (Wu et al. 2021, Huang et al. 2023).

Trends and Threats
Population trends for R. dulongensis have not been described. However, potential threats to the species include habitat modification occurring around 1500 m elevation in Yunnan Province, China. Habitat modifications between 2000 - 2020 included minor increases in farmland and wetlands and decreases in forest, grassland, and shrub habitats. Anthropogenic factors have been shown to influence high-elevation species and may pose a threat to R. dulongensis, but actual concerns are currently unknown (Shi et al. 2022).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Climate change, increased UVB or increased sensitivity to it, etc.

Comments

PHYLOGENETIC RELATIONSHIPS:

References
Huang, J., Liu, X. L., Du, L., Bernstein, J. M., Liu, S., Yang, Y., Yu, G., and Wu, Z. (2023). A new species of Bush frog (Anura, Rhacophoridae, Raorchestes) from southeastern Yunnan, China. ZooKeys 1151, 47–65. [link]

Shi, N., Guo, N., Wang, Q., Han, Y., and Xiao, N. (2022). Spatial pattern and habitat changes of amphibian species in the priority area for biodiversity conservation in the South Hengduan Mountains. Sustainability, 14(16), 10145. [link]

Wu, Y.-H., Liu, X.-L., Gao, W., Wang, Y.-F., Li, Y.-C., Zhou, W.-W., Yuan, Z.-Y., and Che, J. (2021). Description of a new species of bush frog (Anura: Rhacophoridae: Raorchestes) from northwestern Yunnan, China. Zootaxa, 4941(2), 239–258. [link]

Yan, F., Liu, X., Zhang, Y., and Yuan, Z. (2021). Direct development of the bush frog Raorchestes longchuanensis (Yang and Li 1978) under laborary conditions in Southern China. Journal of Natural History, 55(1–2), 125–132. [link]

Species Account Citation: AmphibiaWeb 2024 Raorchestes dulongensis <https://amphibiaweb.org/species/9345> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

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