Annam Narrow-mouthed Frog – Microhyla annamensis – Smith, 1923

Science name: Microhyla annamensis – Smith, 1923

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

Species status: Endemic ; IUCN status: VU (Vunerable)

Description: Physical Characteristics: Microhyla annamensis is a small-sized frog belonging to the family Microhylidae. It has distinctive morphological features with a small, compact body. The species is distinguished by the absence of vomerine teeth, and its skin is smooth or slightly verrucosed. The coloration typically includes a brownish or grayish background with irregular blotches on the sides. The legs often have dark transverse bands.

Coloration: The dorsal surface tends to be brown with some darker markings, including patterns on the back and limbs. The ventral surface is usually lighter in color, often with small, dark spots on the throat and belly.

Distribution and habitat: Altitude: Microhyla annamensis is found at elevations between 1,000 and 2,000 meters above sea level (asl).

Range: This species is currently known with certainty from the Langbian Plateau in the southern reaches of the Vietnamese Central Highlands. It is confined to five threat-defined locations with an estimated extent of occurrence (EOO) of 9,889 km². There have been historical reports of its presence in southeastern Thailand, Cambodia’s Cardamom Mountains, and central Vietnam, but these are now believed to pertain to other species. The species is restricted to the Langbian Plateau.

Habitat: Microhyla annamensis inhabits montane evergreen mixed forests. It is primarily observed on the forest floor. During the breeding season, males call after heavy rains, and amplexing pairs and gravid females can be found near forest streams. Tadpoles develop in temporary pools or slow-flowing stream sections. This species relies on both forest and wetland habitats for breeding.

Behaviour and ecology: Lifestyle: This species is terrestrial and primarily found on the forest floor. It is most active during the rainy season, particularly during and after heavy rainfalls, when it breeds.

Reproduction: Breeding occurs after heavy rains, and males call to attract females. Amplexus has been observed near slow-moving streams, and the tadpoles develop in temporary pools or sections of slow-flowing streams. Breeding has been documented on Bidoup Mountain in July and Chu Pan Phan Mountain in March and April.

Feeding: As a member of the Microhylidae family, Microhyla annamensis is likely insectivorous, feeding on small invertebrates, although specific dietary data is not available.

Conservation and status: IUCN Red List Category and Criteria: Microhyla annamensis is listed as Vulnerable under the IUCN Red List criteria B1ab(iii), indicating that the species is at risk due to declining habitat quality. The assessment was last conducted in February 2015.

Threats: The primary threat to M. annamensis is habitat loss and degradation, driven primarily by agricultural expansion and logging activities. The continued decline in the area, extent, and quality of its montane forest habitat poses a significant risk to the species’ survival.

Conservation Actions: There are currently no species-specific conservation measures in place. However, the species’ range overlaps with some protected areas, which may provide some degree of protection. Conservation actions should focus on habitat preservation and further research into the species’ population trends, distribution, and ecology to inform better protection measures.