AmphibiaChina 中国两栖类.

Description
Microhyla mukhlesuri is a small frog that has a snout-vent length between 16.5 - 21 mm in males and 17.3 - 18.4 mm in females. The head length is about equal to the head width. Its snout is rounded and the nostrils are closer to the snout tip than the eyes. The inter-orbital space is wider than the inter-nostril space. The skin is smooth. The slender fingers are free of webbing and have a relative finger length formula of 1 > 4 > 2 > 3. The tibiotarsal articulation reaches between the eyes to the snout tip and the hind limb length is approximately 1.6 times larger than the snout-vent length. The femur length is shorter than the tibia length. There is rudimentary webbing between the toes and the relative toe length formal is 1 > 2 > 5 > 3 > 4. Neither the fingertips nor the toe tips are widened (Hasan et al. 2014).

DIAGNOSIS:

Microhyla mukhlesuri can be distinguished from other species in the genus by its size, inverted U-shaped mark above the anus, slender fingers, lack of digit discs, rudimentary toe webbing, presence of metatarsal tubercles, and a tibiotarsal articulation that reaches between the eye and snout. More specifically, M. mukhlesuri is smaller than M. heymonsi and larger than M. mymensinghensis. Additionally, M. heymonsi has an X-shaped marking and M. mymensinghensis has a crescent shaped mark above the anus, respectively. The narrow first finger in M. mukhlesuri differentiates it from the wide first finger with a disc in M. butleri. Both M. chakrapanii and M. sholigari have toe tip discs. Full webbing in M. berdmorei differentiates it from M. mukhlesuri’s rudimentary toe webbing. Microhyla mukhlesuri has an outer metatarsal tubercle that differentiates itself from M. ornata, which lacks an outer metatarsal tubercle. The tibio-tarsal articulation in M. mukhlesuri reaches between the eyes to the snout while in M. ruba and M. fissipes, it only reaches the eye (Hasan et al. 2014). Microhyla mukhlesuri is found in sympatry with M. irrawaddy in northern Myanmar, but they can be differentiated because M. mukhlesuri lacks the prominent granular projection found in M. irrawaddy. Lastly, genetic analysis by Yuan et al. (2016) showed that M. mukhlesuri is widespread throughout the Indochina Peninsula while M. fissipes is found north of the Red River Basin.

COLORATION:

In life, M. mukhlesuri has a dark X-shaped dorsal mark beginning at the eyes, narrowing in the front of the forelimbs and slightly widening between the shoulders before broadening and extending to the corners of the groin. At the snout tip, two black bands begin that run through the eyes then fuse together and extend to the groin. The tarsus, tibias, and thighs have multiple brown diagonal bars. There is a black inverted U-shaped mark above the anus and on both sides below the anus, there are multiple speckled dots. The whitish ventral surface is covered with sporadic tiny specks along the throat (Hansan et al. 2014). When preserved in alcohol, M. mukhlesuri has a dark gray to brown dorsal coloration. As in life, the white ventral side is covered with sporadic tiny specks along the throat (Hansan et al. 2014).

VARIATION:

Five males and five females were examined for the species description. Only one of the five males had a distinct black vocal sac. All five females displayed a whitish ventral throat and few fine speckles on the chin and base of the forelimb. Nine individuals displayed the dark X-shaped dorsal mark with similar longitudinal stripes that were described in the holotype. However, one of the nine individuals displayed spots instead of stripes towards the end of the X-marking. One individual only displayed the longitudinal lines on the left half of its body. Additionally, eight individuals displayed the distinct diagonal bars on the tarsal regions, tibias, and thighs; whereas, the other two individuals displayed faint diagonal bars (Hasan et al. 2014).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Bangladesh

View distribution map in BerkeleyMapper.

Microhyla mukhlesuri was first described from the Chittagong district in North Eastern Bangladesh and can also be found in northeastern India, Vietnam, Thailand, Laos, Myanmar, and Malaysia. Further work is needed to fine tune this broad geographic range (Hasan et al. 2014, Yuan et al. 2016, Garg et al. 2019).

Microhyla mukhlesuri occupies a variety of habitats. At the type locality, they were found under grasses on the edge of ponds in calm, cool environments, with soil that is wet and slightly loose (Hasan et al. 2014). In Myanmar, they have been recorded in bamboo forests (Poyarkov et al. 2019). Under the name M. fissipes, M. mukhlesuri has also been reported in lowland scrub forests, grasslands, agricultural lands, and urban habitats. They can be found at elevations up to 2000 m (Lau et al. 2008).

Life History, Abundance, Activity, and Special Behaviors
Microhyla mukhlesuri is a sub-fossorial species and can be found in leaf litter (Lau et al. 2008).

Microhyla mukhlesuri undergoes indirect development with free-swimming tadpoles. In captivity, a single clutch of 79 eggs was observed. This is smaller than those reported for closely related species, M. fissipes and M. okinavensis, which have reported clutch sizes of 209 - 254 and 220 - 910 eggs, respectively. It is presumed that clutch size in M. mukhlesuri is actually more similar to these closely related species and this clutch was smaller because of a smaller, young female, however, more observations are needed (Behr and Rödder 2018).

The developmental period of larvae was between 37 and 98 days, which is similar to M. fissipes and other species of this genus (Behr and Rödder 2018).

Microhyla mukhlesuri has a call duration of 0.23 - 0.31 seconds and 10 - 18 pulses per call. This is similar to M. fissipes, which has a call duration of 0.21 - 0.25 and 15 - 16 pulses per call (Payorkov et al. 2019).

Trends and Threats
Microhyla mukhlesuri was split from M. fissipes and thus many of the same conservation concerns are applicable to M. mukhlesuri. However, M. mukhlesuri has yet to be individually assessed by the IUCN Red List. Microhyla fissipes is listed as a species of “Least Concern” by the IUCN based on its wide distribution and presumed large population. However, the population trend for M. fissipes has been declining fast enough to qualify for being listed in a more threatened category. While there are no major threats to M. fissipes, it may be threatened locally by agrochemical pollution of both the land and the water, as well as the loss of habitat due to agricultural use (Lau et al. 2008).

Relation to Humans
While there is no published information about the human use of M. mukhlesuri, German researchers were able to purchase 20 adult individuals from a Vietnamese commercial importer, which implies that there is a commercialization of some sort present for this species (Behr and Rödder 2018).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Habitat fragmentation
Local pesticides, fertilizers, and pollutants
Long-distance pesticides, toxins, and pollutants

Comments
When M. mukhlesuri was described, Maximum Likelihood analysis based on cytb mtDNA indicated that it was sister to M. fissipes (Hasan et al. 2014). Later Maximum Likelihood and Bayesian analyses, on fragments of 16S ribosomal RNA gene as well as a neurotrophic factor gene, support placing M. mukhlesuri in the M. fissipes species group, along with M. chakrapani, M. fissipes, M. mictura, M. mymensinghensis, and M. okinavensis. Their analyses also indicate that within this group, M. mukhlesuri is the sister to the clade composed of M. chakrapani and M. mymensinghensis, with M. fissipes being the sister to the clade composed of these three species (Garg et al. 2019).

ETYMOLOGY:

The species epithet of “mukhlesuri” is in honor of Dr. Md. Mukhlesur Rahman Khan, a late professor at the Bangladesh Agricultural University who greatly contributed to the local field of amphibian research (Hasan et al. 2014).

References

Behr, N., Rödder, D. (2018). “Larval development stages and husbandry of the Rice Frog Microhyla mukhlesuri Hasan et al., 2014 (Anura: Microhylidae)” Bonn zoological Bulletin, 67(2), 109-116. [link]

Garg S., Suyesh R., Das A., Jiang J., Wijayathilaka N., Amarasinghe A.A.T., Alhadi F., Vineeth K.K., Aravind N.A., Senevirathne G., Meegaskumbura M. and Biju S.D. (2019). "Systematic revision of Microhyla (Microhylidae) frogs of South Asia: a molecular, morphological, and acoustic assessment." Vertebrate Zoology, 69(1), 1-71. [link]

Hasan, M., Islam, M. M., Kuramoto, M., Kurabayashi, A., Sumida, M. (2014) “Description of two new species of Microhyla (Anura: Microhylidae) from Bangladesh” Zootaxa, 3755(5), 401-418. [link]

Lau, M.W.N., Baorong, G., van Dijk, P.P., Iskandar, D. (2008). “Microhyla fissipes”. The IUCN Red List of Threatened Species 2008: e.T135848A4210760. http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T135848A4210760.en. Downloaded on 02 October 2018.

Poyarkov, N. A., Jr, Gorin, V. A., Zaw, T., Kretova, V. D., Gogoleva, S. S., Pawangkhanant, P., Che, J. (2019) “On the road to Mandalay: contribution to the Microhyla Tschudi, 1838 (Amphibia: Anura: Microhylidae) fauna of Myanmar with description of two new species.” Zoological Research, 40(4), 1-33. [link]

Yuan, Z.-H., Suwannapoom, C., Yan, F., Poyarkov Jr., N.A., Nguyen, SN, Chen, H.-M., Chomde, S., Murphy, R.W., Che, J. (2016). "Red River barrier and Pleistocene climatic fluctuations shaped the genetic structure of Microhyla fissipes complex (Anura: Microhylidae) in southern China and Indochina." Current Zoology, 62(6), 531-543. [link]

Species Account Citation: AmphibiaWeb 2021 Microhyla mukhlesuri: Mukhlesur's Narrow-mouthed Frog <https://amphibiaweb.org/species/8124> 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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