|Taxonomic Notes: Chen, J., N. A. Poyarkov, Jr., C, Suwannapoom, A. Lathrop, Y.-H. Wu, W.-w. Zhou, Z.-y. Yuan, J.-q. Jin, H.-m. Chen, H.-q. Liu, T. Q. Nguyen, S. N. Nguyen, T. V. Duong, K. Eto, K. Nishikawa, M. Matsui, N. L. Orlov, B. L. Stuart, R. M. Brown, J. J. L. Rowley, R. W. Murphy, Y.-y. Wang, and J. Che. 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. (synonym: Leptolalax)|
Species Description: Rowley JJL, Le DTT, Tran DTA, Hoang HD, 2011 A new species of Leptolalax (Anura: Megophryidae) from southern Vietnam. Zootaxa 2796:15-28.
Seven tadpoles in stages 25, 26 and 36 have been described. At stages 25 they have a total length range between 29.8 - 43.3 mm and at 26 they range from 41.6 - 57.4 mm. The single stage 36 individual was 43.6 mm in total length and 14.9 mm in body length. The body length ranges at stage 25 were 11.0 - 14.6, and at stage 26, they were 13.0 - 17.2 mm. The body is elongated and elliptical in the dorsal view. It is widest in the middle of the trunk and there is a shallow, but noticeable constriction between the head and the body. In the lateral view, the body is depressed. In the dorsal view the snout is rounded and in the lateral view the is head sub-triangular with a bluntly rounded snout. The oval nostrils are large, directed anterodorsolaterally, and positioned closer to the snout tip than eyes. They have a low, three-lobed rim along the openings. The dorsally positioned eyes are small with anterodorsolaterally directed pupils. The labial tooth row formula is 1(1)/0. The sinistral spiracle is located at the middle of the body. The spiracle tube is tapered and directed posterodorsally with the inner wall fused to the body wall up to the most distal end. Along the flanks are large lateral lymphatic sacks that extend from the spiracle to the end of the body. A lateral line system is visible starting dorsally near the nostrils and eyes and extending above the lymphatic sacs to the dorsal fin and midline of the tail. The dextral vent tube is moderately long and oblique with a posterolaterally directed opening. It attaches to the ventral fin. The tail is moderately long, ranging from 18.8 - 28.7 mm at stage 25, 28.6 - 40.2 mm at stage 26, and being 28.7 mm at stage 36. It is also moderately tall and has well developed musculature with a bluntly tapered tip. The tail fins begin at the body-tail junction and are low with the dorsal fin being slightly taller than the ventral fin. They reach their maximal height in the posterior third of the tail (Vassilieva et al. 2021).
Metamorphs at stages 44 - 46 had snout-vent length ranges of 17.4 - 18.5 mm. They have elongated bodies with bluntly round snouts and slim limbs. They have faintly visible canthus rostralis and supratympanic ridges (Vassilieva et al. 2021).
Adult L. bidoupensis is distinguished morphologically from similar species, L. applebyi and L. melicus, based on its coloring on its ventral surface, small size, bi-colored iris, smooth skin texture, short tibia, and unique male advertising call (Rowley et al. 2011).
Leptobrachella bidoupensis tadpoles can be distinguished from known tadpoles of the genus by a combination of features. More specifically, L. bidoupensis has an elongated bodies with a shallow depression between the head and the body that places it intermediately between the more elongated body of L. mjobergi and the more elliptical bodies of L. gracilis and L. rowleyae. Additionally, a three-lobed, elevated rim around the nostrils differentiates L. bidoupensis from L. oshanensis and possibly L. pelodytoides, which have a four-lobed rim. The combination of the above features and a tail that is twice as long as the body, a pale-brown coloration without a pattern, and a labial tooth row formula of 1(1)/0 differentiates L. bidoupensis from others in the genus (Vassilieva et al. 2021).
In life, adult L. bidoupensis males are dark reddish-brown with black mottling on the dorsal surface and perpendicular thin black stripes on the dorsal side of the arms and legs. The ventral surface, including the throat, arms, and legs, is a similar color but with white speckling. When preserved, males remain a similar color, except on the ventral surface where they become a plain brown. Females in life have similar coloring as males on the dorsal surface but are a light pink on the ventral surface, which turns to pale brown when preserved. Both males and females have a unique eye coloration where the top half of the iris is reddish-brown and the bottom half is silvery gray with a vertical slit pupil (Rowley et al. 2011).
Metamorphs have a dark brown dorsal ground coloration marked with with fine whitish speckling. There is a darker, faint V-shaped interorbital marking and a blackish stripe along the canthus rostralis and supratympanic ridge. The dorsal surfaces of the limbs have dark transverse bars. Additionally, the upper arms are pinkish-orange and there is an oval orange spot on the shoulder. The iris is bicolored with copper in the upper region and silver-grey in the lower region (Vassilieva et al. 2021).
Tadpoles in life, at night, appear unpigmented with semi-transparent fleshy-pink skin. In daylight, the dorsal and lateral surfaces are pale brown with darker surfaces on the back and upper snout. The dorsal fin and the posterior tip of the tail have brownish marbling. The ventral fin is mostly unpigmented with some brown speckling. The lateral lines are white. The skin on the ventrum is transparent, such that the intestinal coils are visible. The spiracle, vent tube, and oral disc are also unpigmented. The iris is black. In preservative, the brown color fades to grey (Vassilieva et al. 2021).
Leptobrachella bidoupensis displays sexual dichromatism on their ventral surfaces with females being pink while males are white. Both males and females are a bit brighter color in life than when preserved, and more change is noticed with preservation in the larger females than in males. Finally, the split of iris color varies with the reddish-brown coloration spreading further down in some individuals (Rowley et al. 2011).
Distribution and Habitat
Life History, Abundance, Activity, and Special Behaviors
The mating calls of male L. bidoupensis consist of a single note lasting on average 9.8 ms and repeated at a rate of about ten calls per second with an average inter-call interval of 86 ms. The slow and rasping single note advertisement call of L. bidoupensis is extremely faint and difficult to hear even when compared to other Leptobranchella species (Rowley et al. 2011).
Eggs were laid on or under rocks near the edge of the stream bank for a few weeks in spring (Tron et.al. 2015).
Various sized tadpoles of L. bidoupensis can be observed in rocky cascaded streams with shallow pools and pebble or rocky bottoms throughout February to June and young metamorphs can be found in June. As a result, the larval period is assumed to lasts several months and possibly over a year. Tadpoles are active at night and hide under rocks to avoid light (Vassilieva et al. 2021).
Other Leptobrachella tadpole species have been observed to have fossorial lifestyles where they have been seen digging in the gravel substrate of the small streams where they are spawned (Chen et.al. 2018). In general, Leptobrachella tadpoles are found in fast-moving streams and possess an extended caudal skeleton that anchors muscles, therefore, assisting in navigating plant debris and burrowing into the stream bed (Handrigan et al. 2007).
Laval L. bidoupensis share their microhabitat with Leptobrachium pullum, Leptobrachium leucops, and Ophryophryne elfina (Vassilieva et al. 2021).
Trends and Threats
Possible reasons for amphibian decline
General habitat alteration and loss
The exact placement of L. bidoupensis is undetermined. A 2018 study indicated that L. bidoupensis is sister to L. pyrrhops. Together they are sister to a clade composed of L. applebyi, L. ardens, and an undescribed Leptobrachella (Chen et al. 2018). This relationship is supported by a 2020 Bayesian analysis on partial 16S mtDNA, however, their results indicate that L. bidoupensis is first sister to L. pallida and then to L. pyrrhops (Luo et al. 2020). Additionally, other 16S mtDNA studies (Chen 2019, 2020) found that L. bidoupensis is sister to the clade composed of L. pallida and L. kaloensis while L. pyrrhops is removed by three degrees of separation.
The species epithet, “bidoupensis” refers to the location where the frog is found, Bidoup-Nui Ba National Park in Langbian Plateau in southern Vietnam (Rowley et al. 2011).
Chen, J. M., Poyarkov, 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, Che, J. (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]
Chen, W., Liao, X., Zhou, S., Mo, Y. (2019). "A new species of Leptobrachella (Anura: Megophryidae) from southern Guangxi, China." Zootaxa 4563(1): 67–82. [link]
Chen, W., Peng, W., Pan, W., Liao, N., Liu, Y., Huang, Y. (2021). "A new species of Leptobrachella Smith 1925 (Anura: Megophryidae) from Southern Guangxi, China." Zootaxa, 5020(3), 581–596. [link]
Handrigan, G. R., Haas, A., Wassersyg R. J. (2007). “Bony‐tailed tadpoles: the development of supernumerary caudal vertebrae in larval megophryids (Anura).” Evolution & Development, 9(6): 190–202. [link]
IUCN SSC Amphibian Specialist Group. (2020). "Leptolalax bidoupensis (amended version of 2015 assessment)." The IUCN Red List of Threatened Species 2020: e.T48101579A176542583.
Luo, T., Xiao, N., Gao, K., Zhou, J. (2020). "A new species of Leptobrachella (Anura, Megophryidae) from Guizhou Province, China." ZooKeys 923: 115–140. [link]
Rowley, J.J.L., Le, D.T.T., Tran, D.T.A, Hoang, D.Y. (2011). “A new species of Leptolalax (Anura: Megophryidae) from southern Vietnam.” Zootaxa, 2796(1): 15-28. [link]
Tron, R., Das, I., Hooroo, J.N.K., Rangad, D. (2015). “Spring-breeding and mode in Leptolalax khasiorum (Anura, Megophryidae) in North-Eastern India.” Russian Journal of Herpetology, 22(3), 224-232. [link]
Originally submitted by: Evan Stanziano, Alexandra Swank, Olivia Thorn (2021-11-22)
Distribution by: Evan Stanziano, Alexandra Swank, Olivia Thorn (updated 2021-11-22)
Trends and threats by: Evan Stanziano, Alexandra Swank, Olivia Thorn (updated 2021-11-22)
Edited by: Ann T. Chang (2021-12-02)
Species Account Citation: AmphibiaWeb 2021 Leptobrachella bidoupensis <https://amphibiaweb.org/species/7642> University of California, Berkeley, CA, USA. Accessed Aug 9, 2022.
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Citation: AmphibiaWeb. 2022. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 9 Aug 2022.
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