Description

DESCRIPTION:

DIAGNOSIS: (How this species is differentiated from similar species)

Compared to other species in Leptolalax, the male holotype of L. nahangensis has a longer snout-vent length (40.8 mm) than L. alpinus (24 - 26.4 mm), L. arayai (30 mm), L. bourreti (36.2 mm), L. dringi (24.2 - 28.5 mm in males), L. hamidi (28 - 31 mm), L. heteropus (24.2 - 28.5 mm), L. pictus (30 - 35 mm), and L. ventripunctatus (22.5 - 28 mm). Additionally, L. nahangensis has shoulder glands, unlike L. gracilis and L. sungi. Leptobrachella nahangensis can also be diagnosed by the lack of lateral fringes on the toes, unlike L. alpinus, L. bourreti, L. heteropus, L. pelodytoides, and L. sungi. The ventral coloration of L. nahangensis is different from L. bourreti, L. dringi, and L. sungi, which have immaculate venters. The coloration of L. nahangensis also differs from L. pelodytoides, which has speckling on the chin surrounding white pustules and white spots scattered on dark brown legs. Leptobrachella nahangensis instead has light mottling from the chin to the throat, with the legs being white on the ventral surface and posterior thighs being light brown with white spots (Lathrop et al. 1998).

COLORATION: (In life and/or in preservative)

In life, L. nahangensis has a brownish-lavender dorsum covered with diffuse, dark gray-black spots, while the ventrum is pinkish-white. The flanks are gray-lavender and are covered with well-defined dark gray-black spots. The limbs and digits have transverse dark bars, and the forearm and heels are yellow-orange. The eyelids are gray. The supratympanic fold is flanked with black and has black accents, while the gland at the end of the fold is white. The tympanum is completely or partially black. Two vertical bars are on the upper lip, with one under the eye and the other in the loreal region. The black canthus rostralis extends over the snout, ending with a light vertical bar at the tip of the snout. The iris is gold with a black reticulated pattern on top (Lathrop et al. 1998).

In preservative, the dorsum and sides appear dark brown-gray while the limbs are light gray to brown-gray with transverse bars. The interorbital bar and canthus appear dark brown to black. The bars on the upper lip are black, and the bar at the tip of the snout remains light in color, lighter than the dorsum. The ventral margin of the supratympanic fold is dark brown. The ventrum is cream-white with subtle mottling on the ventral surface of the forearm, tibio-tarsus, feet, and area from the lower jaw margin to the chest. The femoral gland and pustules are white (Lathrop et al. 1998).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Viet Nam

View distribution map in BerkeleyMapper.

The L. nahangensis holotype was taken from Na Hang Nature Reserve (22°19'94"N; 105°25'79"E), which is located in the Song Gam mountain range in Tuyen Quang Province, Vietnam. The holotype was found near a cave entrance at an elevation of 314 m after a rainstorm. It is believed that L. nahangensis is limited to the Na Hang Nature Reserve, as no specimens could be produced from an adjacent national park just 30 km east. It is thought that several species with narrow distributions such as L. nahangensis occur in Vietnam due to the topography and geologic history of Indochina. Similar species species occur in southeast Asia near rocky streams in damp montane forests (Lathrop et al. 1998).

Life History, Abundance, Activity, and Special Behaviors
Leptobrachella nahangensis has a call composed of a loud, single chirp produced at 30 second intervals (Lathrop et al. 1998).

Leptolalax pelodytoides is sympatric and has a call composed of several chirps (Lathrop et al. 1998).

Larva
Tadpoles from the genus have a subterminal oral disk (Lathrop et al. 1998).

Comments

PHYLOGENETIC RELATIONSHIPS:

Prior to 1998, only two species of the genus were known in Vietnam: L. pelodytoides and L. bourreti. Variation in the amount of genetic material in Vietnamese megophryidae is low. Thus, the observed difference between L. nahangensis (5.46 pg) and L. pelodytoides (5.13 ± 0.05 pg) is significant (Lathrop et al. 1998).

ETYMOLOGY (Origin or explanation of scientific name):

The species epithet, “nahangensis,” is named after the government officials, officers, and people of the Na Hang Nature Reserve, which is the type locality (Lathrop et al. 1998).

References

Chen, J., Poyarkov, Jr., N.A., Suwannapoom, C., Lathrop, A., Wu, Y.-H., Zhou, W.-w., Yuan, Z.-y., Jin, J.-q., Chen, H.-m., Liu, H.-q., Nguyen, T.Q., Nguyen, S.N., Duong, T.V., Eto, K., Nishikawa, K., Matsui, M., Orlov, N.L., Stuart, B.L., Brown, R.M., Rowley, J.J.L., Murphy, R.W., Wang, Y-y., and Jing, C. (2018). "Large-scale phylogenetic analyses provide insights into unrecognized diversity and historical biogeography of Asian leaf-litter frogs, genus Leptolalax (Anura: Megophryidae)." Molecular Phylogenetics and Evolution, 124, 162-171. [link]

Lathrop, A., Murphy, R. W., Orlov, N., Ho, C.T. (1998). "Two new species of Leptolalax (Anura: Megophryidae) from northern Vietnam." Amphibia-Reptilia, 19(3), 253-267. [link]

Species Account Citation: AmphibiaWeb 2023 Leptobrachella nahangensis: Nahang Asian Toad <https://amphibiaweb.org/species/5478> University of California, Berkeley, CA, USA. Accessed Apr 26, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 26 Apr 2024.

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