Darexsky’s narrow-mouth frog – Microhyla darevskii – Poyarkov, Vassilieva, Orlov, Galoyan, Tran, Le, Kretova & Geissler, 2014

Science name: Microhyla darevskii – Poyarkov, Vassilieva, Orlov, Galoyan, Tran, Le, Kretova & Geissler, 2014

Taxonomic:  Animalia>> Chordata>> Amphibia>> Anura >> Microhylidae >> darevskii

Species status: Endemic ; IUCN status: LC (Least Concern)

Description:

Physical Characteristics: Microhyla darevskii is a large-sized member of the genus Microhyla, with adult males measuring between 27.0 and 32.6 mm in snout-vent length. The species has a broad, triangular head, a strongly flattened body, and slightly tubercular or pustulate skin on the dorsum. The toes are webbed, and both fingers and toes lack disks, though the toes may have weakly dilated tips.

Coloration: The species displays a distinctive olive-brown dorsal coloration with a bronze tint on the sides and a darker, butterfly-shaped dorsomedial pattern edged in cream. There is a prominent dark brown interorbital bar shaped like an inverted triangle, and a dark trapezoid marking is visible above the cloacal opening. The ventral surface is generally light cream with dark gray spots on the chin and throat.

Distribution and habitat:

Altitude: Microhyla darevskii is found at an elevation of approximately 1,500 meters above sea level (asl).

Range: This species is known only from the central Annamite Mountains in Kon Tum Province, Vietnam. It is possible that the species also occurs in similar habitats in southern Quang Nam and northeastern Gia Lai Provinces in Vietnam, as well as in southeastern Xekong and northeastern Attapu Provinces of Laos. The estimated extent of occurrence (EOO) is 1,156 km², with its range consisting of two threat-defined locations.

Habitat: Microhyla darevskii inhabits a variety of habitats, including montane mixed evergreen forests, grasslands, and wetlands. Males have been recorded near temporary rain pools in pastures close to forested areas. However, little is known about the species’ preferred breeding habitats or reproductive biology, though it is assumed to have an aquatic larval stage like other members of its genus.

Behaviour and ecology:

Lifestyle: Microhyla darevskii is a terrestrial species that has been observed calling from shelters in leaf litter or soil, particularly near temporary rain pools in grassy areas close to forests.

Reproduction: Very little is known about the reproductive behavior of this species. Males have been found near temporary rain pools, suggesting that breeding may occur in these ephemeral habitats, as is typical for other species in the Microhyla genus. It is presumed that the species deposits eggs in water, where larvae develop until metamorphosis.

Feeding: As with many other members of the Microhyla genus, M. darevskii is likely insectivorous, feeding on small invertebrates, though specific dietary data is lacking.

Conservation and status:

IUCN Red List Category and Criteria: Microhyla darevskii is currently listed as Data Deficient under the IUCN Red List. This status reflects the lack of comprehensive data on the species’ population size, trends, and specific threats. The assessment was last conducted in August 2020.

Threats: The primary threat to M. darevskii is habitat loss, particularly due to deforestation, agricultural expansion, and logging in the Annamite Mountains. The species’ reliance on montane habitats makes it particularly vulnerable to these forms of habitat degradation.

Conservation Actions: There are no specific conservation measures currently in place for Microhyla darevskii. However, the species occurs in the region of Ngoc Linh Mountain, which is a part of Vietnam’s protected areas. Further research is needed to clarify the species’ distribution, population size, and ecology to inform effective conservation strategies.