Tay Nguyen Dwarf Frog – Vietnamophryne inexpectata – Poyarkov, Suwannapoom, Pawangkhanant, Aksornneam, Duong, Korost & Che, 2018

Science name: Vietnamophryne inexpectata – Poyarkov, Suwannapoom, Pawangkhanant, Aksornneam, Duong, Korost & Che, 2018

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

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

Description: Physical Characteristics:
Vietnamophryne inexpectata is a small, miniaturized frog species with a stout body. The snout-vent length (SVL) of the single known male specimen is 14.2 mm. It has a head as wide as it is long, with an obtuse, short snout. The eye is medium-sized, with a rounded tympanum that is well separated from the eye. The skin on the dorsal and lateral surfaces is shagreened (rough) anteriorly and distinctly warty posteriorly, while the ventral surface is completely smooth.

Its digits are rounded at the tips, and finger webbing is absent, although toes show slight webbing. The coloration of V. inexpectata is grayish-brown dorsally, with small reddish speckles anteriorly and darker tubercles posteriorly. Ventrally, it is gray-beige with light gray marbling, particularly on the chest, throat, and limbs.

Distribution and habitat: Altitude:
Vietnamophryne inexpectata is found at an elevation of 1,000 meters above sea level.

Range:
This species is currently known from a single locality within Kon Chu Rang Nature Reserve in Gia Lai Province, central Vietnam. The known extent of occurrence (EOO) is only 45 km². However, it is likely that its range could extend beyond this location into similar habitats found in adjacent areas, but further surveys are necessary to confirm this.

Habitat:
The species is associated with primary evergreen montane forests. The only observed individual was found beneath soil and leaf litter in a cavity under a log near a small cascading stream, indicating a possible semi-fossorial (partly subterranean) lifestyle. The surrounding forest is characterized by large trees and heavy undergrowth, which may be crucial for the species’ survival. The ongoing decline in forest quality and extent due to agricultural activities is a significant concern for this species’ habitat.

Behaviour and ecology: Lifestyle:
The frog is presumed to have a partly subterranean lifestyle, spending much of its time under leaf litter or logs. The single individual was found after heavy rainfall, suggesting that weather conditions may play a role in its activity. Its reproductive biology is unknown, but it is speculated that it may reproduce via direct development, bypassing the tadpole stage, similar to related species in genera like Oreophryne and Cophixalus. There is no information on calling behavior or diet.

Reproduction:
No reproductive behavior has been observed for this species. However, given its association with similar genera, it is hypothesized that it may reproduce through direct development, a process in which frogs lay eggs that hatch directly into miniature frogs without passing through a free-swimming tadpole stage.

Conservation and status: IUCN Red List Category and Criteria:
Vietnamophryne inexpectata is listed as “Data Deficient” on the IUCN Red List. This status reflects the lack of sufficient data on its population size, distribution, and trends. The species was only discovered in 2016, and further research is needed to assess its conservation status accurately.

Threats:
The main threat to Vietnamophryne inexpectata is habitat loss and degradation due to agricultural expansion in central Vietnam. The region has seen a steady decline in forest cover, which is likely affecting this species’ habitat. The species has not been found in disturbed areas, indicating a reliance on undisturbed primary forest habitats.

Conservation Actions:
Conservation efforts should focus on protecting the primary montane forests where this species is found. Since only a single specimen has been documented, further surveys in adjacent areas are necessary to better understand the species’ distribution, population size, and ecology.