Trankien Frog – Odorrana trankieni – (Orlov, Le & Ho, 2003)

Science name: Odorrana trankieni – (Orlov, Le & Ho, 2003)

Taxonomic:  Animalia>> Chordata>> Amphibia>> Anura >> Ranidae >> trankieni

Species status: Endemic ; IUCN status: NT (Near Threatened)

Description:

Physical Characteristics:
Odorrana trankieni is a cascade frog, recognized by its long and broad head with a narrow, protruding snout. The head is slightly concave between the orbits, and the nostrils are located about halfway between the tip of the snout and the eye. The supratympanic fold is well-developed, and the tympanum is about 61% of the eye’s length, separated from the eye by about two-thirds the diameter of the tympanum. The fingers and toes are highly webbed, with the webbing extending to the proximal border of the toe discs and the distal tip of the ultimate phalange.

Coloration:
The dorsal coloration is green with diffuse red-brown spots, while the belly is light with poorly developed spots. The throat is dark, and the flanks are grey with dark spots. The limbs have distinct transverse dark bands: three on the forelimbs and 12 on the hind limbs.

Distribution and habitat:

Altitude:
Odorrana trankieni is found at elevations ranging from 300 to 700 meters above sea level (asl). It inhabits montane evergreen forests and secondary mixed evergreen bamboo forests in northern Vietnam.

Range:
This species is currently known from Hoa Binh, Bac Giang, and Son La Provinces in Vietnam, with an estimated extent of occurrence (EOO) of 22,242 km². Similar habitats are present in adjacent regions of Vietnam and southern China, suggesting its range may extend beyond the currently known locations. The species is found in approximately five to ten threat-defined locations.

Habitat:
Odorrana trankieni is associated with small cascade forest streams and rocky streams. Individuals are often found on rocks along these streams. While little is known about its reproductive biology, it is presumed that, like other Odorrana species, it breeds in streams with larval development occurring in water. Habitat quality and extent are under threat due to expanding agriculture and coal mining activities.

Behaviour and ecology:

Lifestyle:
Odorrana trankieni is a stream-dwelling species, adapted to fast-flowing cascade streams in forested areas. It is typically found on stony banks near waterfalls and streams with crystal-clear water.

Reproduction:
Although specific details about its reproduction are unknown, it is presumed to follow the reproductive patterns of other Odorrana species, which breed in streams and develop through a larval stage in the water.

Conservation and status:

IUCN Red List Category and Criteria:
Odorrana trankieni is listed as “Near Threatened” (B1ab(iii)) due to its limited range, fragmented population, and ongoing habitat degradation. The species was last assessed in 2020.

Threats:
The primary threats to O. trankieni include habitat loss due to expanding agriculture and coal mining, which contribute to the decline in forest and stream quality. The continued degradation of its habitat poses a significant risk to its survival.

Conservation Actions:
There are no specific conservation measures in place for Odorrana trankieni. However, conservation efforts should focus on protecting montane forest ecosystems and reducing the impact of agriculture and mining activities in its habitat. Further research is needed to better understand its population size, trends, and ecological requirements.