Cat Ba Shrub Frog – Philautus catbaensis – Milto, Poyarkov, Orlov & Nguyen, 2013

Science name: Philautus catbaensis – Milto, Poyarkov, Orlov & Nguyen, 2013

Taxonomic:  Animalia>> Chordata>> Amphibia>> Anura >> Rhacophoridae >> catbaensis

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

Description: Physical Characteristics:
Philautus catbaensis is a small-sized frog species. Males typically have a snout-vent length (SVL) of around 18.6 to 20.9 mm, while females are slightly larger, with an SVL of 19.4 to 22.7 mm. The species is characterized by a broad head, rounded snout, and a distinct tympanum that is smaller than the eye. The fingers have well-developed discs but lack full webbing, and the toes exhibit moderate webbing. The dorsal coloration is gray or brown, with males being gray or gray-brown and females more brown. Both sexes have a distinctive reddish spot near the groin.

Coloration:
In preserved specimens, the dorsal coloration of P. catbaensis is gray, with brown patterns on the head and dorsum. A reddish lateral spot near the groin is present in both males and females. The ventral surface is white, and the limbs display light coloration with dark transverse bands.

Distribution and habitat: Altitude:
The altitude range for Philautus catbaensis has not been reported, but its known habitat, Cat Ba Island, includes elevations from approximately 0 to 300 meters above sea level (asl).

Range:
This species is known only from Cat Ba National Park on Cat Ba Island in northern Vietnam. Although its presence is restricted to this location, similar habitats elsewhere on the island may also harbor the species. Its estimated extent of occurrence (EOO) is 198 km², consisting of five or fewer threat-defined locations.

Habitat:
Philautus catbaensis is primarily associated with vegetation in limestone landscapes covered by primary tropical forest. Its habitat consists of moist tropical forests that grow on karstic rock formations. The quality and extent of these forests are undergoing a continuing decline due to expanding agriculture and human activities, posing a threat to the species.

Behaviour and ecology: Lifestyle:
Philautus catbaensis is a nocturnal species that inhabits tropical limestone forests. It is often found on vegetation during the night. The species is highly dependent on intact forest habitats and does not tolerate disturbed areas.

Reproduction:
Very little is known about the reproductive biology of P. catbaensis, as its genus exhibits varying reproductive strategies. It is assumed that this species, like others in the genus, likely breeds in the moist vegetation of the forest.

Conservation and status: IUCN Red List Category and Criteria:
Philautus catbaensis is listed as “Endangered” (B1ab(iii)) due to its limited range, declining population, and ongoing habitat degradation. It was last assessed in 2020.

Threats:
The primary threat to P. catbaensis is the continuing decline in the quality and extent of its forest habitat. Agricultural expansion and other forms of habitat alteration, such as infrastructure development, are significant pressures on the remaining suitable areas of limestone forest.

Conservation Actions:
No specific conservation measures are in place for P. catbaensis. However, it resides in Cat Ba National Park, which may offer some degree of protection. Conservation efforts should focus on preserving the forested karst landscapes of Cat Ba Island. Further research is needed to understand the species’ ecology, population trends, and reproductive behavior to inform future conservation actions.