AmphibiaWeb - Leptobrachella botsfordi
AMPHIBIAWEB
Leptobrachella botsfordi
Botsford’s leaf-litter frog
family: Megophryidae
subfamily: Leptobrachiinae
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 JJ, Dau VQ, Nguyen TT 2013 A new species of Leptolalax (Anura: Megophryidae)from the highest mountain in Indochina. Zootaxa 3737:415-428.

© 2017 Benjamin Tapley/ZSL (1 of 5)
Conservation Status (definitions)
IUCN (Red List) Status Critically Endangered (CR)
CITES No CITES Listing
National Status None
Regional Status None
Access Conservation Needs Assessment Report.

   

 

View distribution map in BerkeleyMapper.

Description
Leptobranchella botsfordi, also known as the Botsford’s leaf-litter frog, is a small-bodied frog with the snout-vent length in adult males measuring between 29.1 - 32.6 mm and adult females between 30.0 - 31.8 mm. The head length and width are equal in size. The snouts are round and the nostrils are equal to the distance between the snout and eyes. The canthus rostralis is somewhat rounded making it less distinguishable. They have vertical pupils, and eye diameters smaller than the length of the snout. They lack a pineal ocellus. The tympanums are round, yet not very distinct. Ventrally, the tympanic rim is elevated relative to the skin along the temporal region. The supratympanic ridge is obvious and has raised tubercles, running from the eye to the axillary gland. The fingertips are swollen and rounded. The relative finger lengths are I < II < IV < III. Nuptial pads, subarticular tubercles, finger webbing, and dermal fringes are all absent. The toe tips resemble the fingertips in that they are rounded and vary in length. The relative toe lengths are I < II < V < III < IV. The toes exhibit simple webbing and narrow lateral fringes. The skin is smooth on the ventral side of the body and rough on the dorsal side. The pectoral and femoral glands are large and oval, with diameters of 1.5 mm and 3.4 mm, respectively. The supra-axillary gland is raised and measures 1.8 mm in diameter. Anteriorly, the ventrolateral glands form a partial line with small white dotting (Rowley et al. 2013).

Tadpole morphology is based on two specimens, one at stage 25 and the other at stage 26. The body is elongated and laterally depressed with total lengths being 28.3 and 39.7 mm. Body lengths were 9.2 and 14.4 mm and body widths 4.2 and 7.0 mm. They have rounded snouts with anterodorsal nostrils that sit closer to the snout than the eyes. The eyes are small, yet clearly visible and are positioned dorsolaterally. Their mouths consist of a cup-like anteroventral oral disc with short and pointy cone-like papillae. Both the upper and lower sheaths have serrated edges. The ​​labial tooth row formula is 3(1 - 3)/4(1 - 3). The cone-like sinistral spiracle is positioned anteriorly towards the widest part of the body. The tails are long, spanning nearly twice the length of the body at 19.1 and 25.3 mm, and have round tips. The maximal tail muscle width ranges from 2.2 and 4.4 mm. The tail height measures 3.0 and 5.7 mm, including the fins. The tail fins are low, and both the upper and lower fins reach their maximum height at around two-thirds of the tail length. The upper fins range in height from 0.8 and 1.1 mm, and the lower fin heights measured 0.8 mm (Nguyen et al. 2020).

Adult L. botsfordi can be distinguished from the majority of other frogs in Leptobrachella by the brownish-red coloration on its back with small white spots. Additionally, L. botsfordi lack black markings on its side, has weak lateral fringing on its toes, and has sizable pectoral and femoral glands. Its call can be another determinant with a frequency of 2.6 - 3.2 kHz and an average 1 - 3 notes per call (Rowley et al. 2013).

At Gosner stage 25 and 26, L. botsfordi can be distinguished from L. bourreti at stages 25 - 31 by having a shorter total length, smaller eyes, and shorter upper fin. Additionally, while L. botsfordi has a whitish-brown to grey body without spots, L. bourreti is olive grey with light spots on the head (Nguyen et al. 2020).

Adult L. botsfordi in life, are dark brown dorsally with gold on the dorsolateral edge. There is also a gold interorbital bar. The tip of the snout and the supratympanic ridge are metallic copper. The flanks are patterned with a marbling of brown and gold. There are faint brown horizontal bars along appendages, fingers and toes, thighs, tibia, tarsus, and the lower section of arms. The white supra-axillary gland is also edged with pale copper. The pectoral and femoral glands are also white. The reddish-brown ventral surface is somewhat transparent and speckled with pale flakes that are more obvious on the throat and thighs, which are darker. In preservative, the gold surfaces fade to pale brown (Rowley et al. 2013).

In life, tadpoles have whitish-brown to grey bodies with whitish lines around the nostrils and eyes. There are also whitish lines that run dorsolaterally along the body and then laterally along the tail. The iris and jaw sheaths are black. The ventral surface is translucent and the coiled gut can be seen through the skin. The tail musculature is dark grey to whitish brown and the fins are whitish brown (Nguyen et al. 2020).

In life, a metamorph at stage 44 is brown dorsally with reddish-orange tubercles. Dorsolaterally, they have a reddish orange edge to their dorsal color that transitions to light brown with white spots on the dorsolateral and ventral surfaces. As with the adults, the glands on the body are white (Nguyen et al. 2020).

The specimens used to describe this species only had slight variation in coloration and the amount of mottling on their dorsums. Males have more robust arms than females (Rowley et al. 2013).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Viet Nam

 

View distribution map in BerkeleyMapper.
Leptobrachella botsfordi was described from specimens found in a small forest in Hoang Lien National Park on Mount Fansipan in Northern Vietnam and its Extent of Occurrence is 36 km2. This species has been found between elevations of 2,500 to 2,815 m. It is hypothesised that the range may be larger, extending into the Lai Chai, and Yunnan provinces from the northwest to the southeast (Rowley et al. 2013, Nguyen et al. 2020).

The habitat for the species is along streams in high elevation mountains of Northern Vietnam with riparian habitat. The forest consists of bamboo, pine, evergreen, and broadleaf trees. It is important for these streams to have gravel bottoms for breeding and development of tadpoles (Rowley et al. 2013).

Life History, Abundance, Activity, and Special Behaviors
Leptobrachella botsfordi appears to be seasonally active; adults were only observed from April through to September (Nguyen et al. 2020). In fact, adults may have an adaptation to this short activity period, as they have been found with large fat reserves, greater than those of similar species. This may also be an adaptation to living at higher altitudes (Rowley et al. 2013).

The breeding period for this species appears to begin in June, and males can be observed calling until September. While adults can be difficult to find, males have been observed calling under leaf litter nearby streams and females were found moving towards the males (Rowley et al. 2013).

In the field, L. botsfordi sounds like a cricket chirping. Leptobrachella botsfordi has two advertising calls, separated into primary and secondary calls, with variations in their amplitude and number of notes and pulses. The primary calls are made at higher amplitudes than the secondary calls, and are also more numerous. They last for 267 ms and are made up of three notes, with varying amounts of pulses that always decrease with each subsequent note. Secondary calls are of lower amplitude and last slightly longer than primary calls in duration at 299 ms. They are only made up of one note, with 14 - 19 pulses (Rowley et al. 2013).

Leptobrachella botsfordi has indirect development and aquatic larvae. The larvae themselves were found at the base of waterfalls underneath rocks in streams with gravel or rocky bottoms and metamorphosis of an individual was recorded late June 2019. However, tadpoles may overwinter, as they have been found in waters from September to December. At the time these tadpoles were collected, the temperature was 9.2 °C, pH was 6.0, general hardness was 30, and nitrates, nitrites, phosphates, and alkalinity were all 0.0 ppm (Nguyen et al. 2020).

Trends and Threats
As of 2015, this species has a threat status of “Critically Endangered” as their known populations continue to decline. There are several causes for this species decline, however, the largest threat is habitat loss. Due to deforestation, fires, and urban development, the natural landscapes inhabited by L. botsfordi are under constant pressure (IUCN 2015). The species is that they are currently only found within the Hoang Lien National Park. Pollution from tourism at this park poses a threat, especially because the species is only found at a specific, narrow, high elevation tropical montane cloud forests that may be at risk to climate change (Rowley et al. 2013). Finally, gravel mining, which impacts oviposition sites, appears to negatively impact this species, as no tadpoles in one study were found where gravel had been removed (Nguyen et al. 2020).

Comments
The resolution for phylogenetic relationships in Leptobrachella is poor. A 2018 large-scale phylogenetic study, using Bayesian and Maximum Likelihood methods on six nuclear genes, found that L. botsfordi is sister to a clade containing L. alpinus, L. sungi, L. zhangyapingi and several other described and undescribed species with high confidence (Chen et al. 2018). This was supported by a 2020 Bayesian analysis on partial 16S rRNA, however the confidence in this placement was low (Luo et al. 2020). However, two other studies using Bayesian analyses on partial 16S rRNA contradict this placement, instead placing L. botsfordi as sister to L. croceus then L. tuberosus. However, these results also had low confidence (Chen et al. 2019, 2020). While the 2018 Chen et al. study did include L. croceus and L. tuberosus in their analysis, and did not find them to be a sister species of L. botsfordi, Luo et al. (2020) did not include L. croceus or L. tuberosus.

Leptobrachella botsfordi belongs to the family Megophryidae and the genus Leptobrachella. However, the species was first named Leptolalax botsfordi until Chen et al. (2018) preformed a large-scale phylogenetic study using morphological characters and six nuclear genes that sunk Leptolalax into Leptobrachella.

Leptobrachella botsfordi is named after Christopher Botsford for his work in Asia building scientific capacity and support of amphibian conservation research (Rowley et al. 2013).

References

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]

IUCN SSC Amphibian Specialist Group. (2015). "Leptolalax botsfordi." The IUCN Red List of Threatened Species 2015: e.T73727195A73727483. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T73727195A73727483.en. Downloaded on 28 May 2015

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]

Nguyen, L.H., Tapley, B., Cutajar, T., Nguyen, C.T, Portway, C., Harding, L., Loung, H.V., Rowley, J.L.L. (2020). “A description of the tadpole of the critically endangered Botsford’s leaf-litter frog (Leptobrachella botsfordi) with comments on the distribution and conservation status of the species.” Zootaxa 4860(2): 293–300. [link]

Rowley, J.J., Dau V.Q., Nguyen, T.T. (2013). “A new species of Leptolalax (Anura: Megophryidae) from the highest mountain in Indochina.” Zootaxa, 3737(4): 415–28. [link]



Originally submitted by: Sierra Cannon, Sierra Teemsma, Maria Froelich (2021-11-30)
Description by: Sierra Cannon, Sierra Teemsma, Maria Froelich (updated 2021-11-30)
Distribution by: Sierra Cannon, Sierra Teemsma, Maria Froelich (updated 2021-11-30)
Life history by: Sierra Cannon, Sierra Teemsma, Maria Froelich (updated 2021-11-30)
Trends and threats by: Sierra Cannon, Sierra Teemsma, Maria Froelich (updated 2021-11-30)
Comments by: Sierra Cannon, Sierra Teemsma, Maria Froelich (updated 2021-11-30)

Edited by: Ann T. Chang (2021-11-30)

Species Account Citation: AmphibiaWeb 2021 Leptobrachella botsfordi: Botsford’s leaf-litter frog <https://amphibiaweb.org/species/8092> University of California, Berkeley, CA, USA. Accessed Jan 19, 2022.



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Citation: AmphibiaWeb. 2022. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 19 Jan 2022.

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