Pretty narrow-mouth frog – Microhyla pulchella – Poyarkov, Vassilieva, Orlov, Galoyan, Tran, Le, Kretova & Geissler, 2014

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

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

Species status: Endemic ; IUCN status: EN (Endangered Species)

Description: Physical Characteristics:
Microhyla pulchella is a small to medium-sized species. The adult males have a snout-vent length (SVL) ranging from 14.7 to 21.6 mm, while females can grow slightly larger, with an SVL of 18.1 to 25.8 mm. The head is moderately stocky, and the snout is bluntly rounded. The skin on the dorsum is smooth, and the species exhibits a distinct pattern of coloration, including a brown dorsal surface with various markings. A thin light vertebral stripe is present, along with several small dark spots scattered across the dorsum. The flanks are darker, and the ventral surfaces of the body are light, often cream-colored, with light brown marbling. Males also possess a median subgular vocal sac, which is slit-like in appearance.

Coloration:
In life, the dorsum of M. pulchella is pinkish-brown with distinct wood-grain-like patterns that run across the body. The back displays a prominent brown triangular interorbital bar. There is darker pigmentation near the groin, and a series of lighter bands or stripes run along the sides of the body. The limbs are marked with cross-bars, while the ventrum is cream-white with faint brown marbling toward the midline.

Distribution and habitat: Altitude:
Microhyla pulchella is found at elevations ranging from 1,490 to 2,048 meters above sea level (asl). It occupies montane regions, particularly within the moist montane evergreen forests of south-central Vietnam.

Range:
This species is known only from two national parks in south-central Vietnam: Bidoup-Nui Ba National Park in Lam Dong Province and Chu Yang Sin National Park in Dak Lak Province. However, its range may extend beyond these areas, as similar habitats and elevations are found in adjacent parts of the Annamite Mountains, including sections of Khanh Hoa and Ninh Thuan Provinces. The estimated extent of occurrence (EOO) for M. pulchella is approximately 3,901 km², consisting of five threat-defined locations.

Habitat:
Microhyla pulchella is associated with moist montane evergreen forests and is primarily terrestrial. The species inhabits areas near permanent rivers and streams, as well as temporary pools, which are critical for breeding. During the breeding season, males, gravid females, and amplexing pairs have been observed near small streams, while tadpoles have been found in temporary pools rather than directly in streams.

Behaviour and ecology: Lifestyle:
Microhyla pulchella is a terrestrial species commonly found near freshwater sources in montane forest habitats. It is most active during the rainy season when breeding activity has been observed.

Reproduction:
Reproductive activity in M. pulchella has been recorded during the rainy season in April, with males calling, females carrying eggs, and mating pairs (amplexus) observed near small streams. Although breeding behavior in streams has been noted, the tadpoles of this species are found in temporary pools, indicating that these ephemeral water bodies play a significant role in the early life stages.

Feeding:
As with most species of the genus Microhyla, M. pulchella is likely insectivorous, feeding on small invertebrates. However, detailed dietary studies are lacking.

Conservation and status: IUCN Red List Category and Criteria:
Microhyla pulchella is listed as “Endangered” under the IUCN Red List (category B1ab(iii)) due to its restricted range, fragmented population, and ongoing habitat loss. The species was last assessed in 2015, and its population is currently declining.

Threats:
The primary threat to M. pulchella is habitat destruction, particularly due to deforestation and agricultural expansion in its montane forest habitat. Logging and land conversion for agriculture threaten the quality and extent of the species’ habitat. Additionally, changes in climate could impact the availability of suitable habitats and breeding sites.

Conservation Actions:
There are currently no specific conservation measures in place for Microhyla pulchella. However, the species is found in two protected areas: Bidoup-Nui Ba and Chu Yang Sin National Parks, which may offer some degree of habitat protection. Further research is needed to better understand the species’ population size, trends, and ecological requirements, as well as to assess the effectiveness of these protected areas in preserving its habitat. Conservation efforts should focus on preserving montane forest ecosystems and mitigating habitat loss.