Night Litter Frog – Leptobrachella nyx – (Ohler, Wollenberg, Grosjean, Hendrix, Vences, Ziegler & Dubois, 2011)

Science name: Leptobrachella nyx – (Ohler, Wollenberg, Grosjean, Hendrix, Vences, Ziegler & Dubois, 2011)

Taxonomic:  Animalia>> Chordata>> Amphibia>> Anura >> Megophryidae >> nyx

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

Description:

Size and Physical Characteristics: Leptobrachella nyx is a small frog. Males typically measure about 23–25 mm in snout-vent length (SVL), while females are slightly larger, ranging from 27–29 mm SVL.

Coloration in Life: In life, this species has a reddish-brown or dark brown dorsal coloration, often with distinct dark spots. Its limbs are marked by dark barring, while the flanks are lighter and speckled with darker spots. The species is known for its striking golden iris, which features fine black reticulations, and a dark facial mask that extends from the snout through the eyes.

Coloration in Preservative: After preservation, the species’ vibrant colors fade considerably. The base coloration dulls, and the contrast between the dark spots and the brownish base becomes less distinct. However, the overall dorsal pattern remains visible.

Distribution and habitat:

Geographic Range: Leptobrachella nyx is currently known only from Cao Bo Commune in Vi Xuyen District, Ha Giang Province, Vietnam. Its range is highly restricted to this region, though it may extend into nearby areas with similar habitat conditions. There are suggestions of its potential presence in southeastern Yunnan Province, China, but no confirmed records have been made.

Elevation: This species has been found at elevations ranging between 800 and 1,700 meters above sea level in montane regions.

Area: Leptobrachella nyx inhabits evergreen montane forests in northeastern Vietnam. The known extent of occurrence is estimated to be approximately 2,096 km², comprising fewer than five known threat-defined locations.

Habitat: It is primarily associated with riparian zones along forested streams. The humid microhabitats it prefers include areas with dense forest cover, near permanent rivers or streams, where it thrives in leaf litter on the forest floor. This species likely requires high humidity and shaded environments to maintain its ecological niche.

Behaviour and ecology:

Reproductive Biology: Though not extensively studied, it is presumed that Leptobrachella nyx shares similar reproductive strategies with other species in the genus. The species likely lays its eggs in small streams, where tadpoles develop in the water. Males are known to call from stream banks or directly within the water during the breeding season, typically in April and May.

Habitat Use: Leptobrachella nyx is nocturnal and most active at night, foraging for small invertebrates in the forest leaf litter. During the day, it remains hidden beneath ground cover, such as leaves or stones, in the humid forest environment.

Conservation and status:

IUCN Red List Category and Criteria: Leptobrachella nyx is currently listed as Data Deficient by the IUCN Red List due to the lack of sufficient information on its population size and trends. However, its restricted range and threats to its habitat indicate that it may be at risk of becoming endangered.

Population Trend: The population trend is currently unknown, though habitat destruction and degradation suggest that it may be in decline.

Threats: The primary threat to Leptobrachella nyx is habitat destruction, mainly due to deforestation and agricultural expansion. Logging and conversion of forest areas into farmland have significantly impacted the species’ habitat, reducing both its area and quality. In addition, climate change may pose a future threat by altering the microhabitat conditions critical for its survival.

Conservation Actions: Conservation efforts should prioritize protecting the remaining montane forests in Ha Giang Province. Further research is needed to understand the species’ population size, distribution, and ecological needs better. Enhanced habitat protection and monitoring programs could help mitigate the effects of habitat destruction and other threats faced by Leptobrachella nyx.