''Gracixalus nonggangensis'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

shrub frog The Rhacophoridae are a family of frogs that occur in tropical sub-Saharan Africa, South India and Sri Lanka, Japan, northeastern India to eastern China and Taiwan, south through the Philippines and Greater Sundas, and Sulawesi. They are commonly ...

found in southern

Guangxi Guangxi (; ; Chinese postal romanization, alternately romanized as Kwanghsi; ; za, Gvangjsih, italics=yes), officially the Guangxi Zhuang Autonomous Region (GZAR), is an Autonomous regions of China, autonomous region of the People's Republic ...

, China, and Cao Bang Province in northern Vietnam.

Taxonomy and systematics

A population previously thought to be a separate species, as ''Gracixalus waza'', was described from the Ha Lang District in northern Vietnam. This population was named for the World Association of Zoos and Aquariums (WAZA), to acknowledge their support of amphibian research and conservation in Vietnam and the common name Waza treefrog was suggested for it. It is now considered as a junior synonym of ''Gracixalus nonggangensis''.

Description

''Gracixalus nonggangensis'' is a medium-sized species compared to others in its genus. Adult males measure in snout–vent length and females . The snout is rounded, slightly protruding. The head is as wide or wider than it is long. The tympanum is distinct and rounded, and the canthus rostralis is rounded. The supratympanic fold is distinct. The forelimbs are relatively short. The fingers have no webbing but have well-developed discs at their tips. The toes are webbed. The toe discs are smaller than the finger discs. The skin is smooth except for some granularity behind the tympanum, flanks, belly, and the limbs. Dorsal coloration varies from light greenish brown to moss-green. There is a dark brown, blotched pattern between eyes that continues backwards as two bands (forming a Y-like mark), and a dark stripe in the middle of posterior part of dorsum. The limbs have some dark brown bands. The throat and chest are white with dark brown marbling, whereas the belly is immaculate white.

Habitat and conservation

In Vietnam, ''Gracixalus nonggangensis'' seems to be associated with

karst Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant ro ...

landscape. Specimens were found near cave entrances and in valleys surrounded by

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

mountains, with the main habitat in the area being secondary karst forest consisting of hardwoods mixed with shrubs and vines. The elevational range is

above sea level Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The comb ...

. The records are some distance away from water (minimum distance about ). The call was not heard during the periods surveys. Animals are active by night. Most individuals were found low on trees some above the ground, but two individuals were found on a limestone cliff inside a cave. Several other karst species have been found in the same area, including the gecko ''

Goniurosaurus luii ''Goniurosaurus luii'' is a species of gecko, a lizard in the family Eublepharidae. The species is endemic to China and Vietnam.. www.reptile-database.org. Etymology The specific name, ''luii'', is in honor of Chinese herpetologist Wai Lui.Beol ...

'' and the snake ''

Elaphe moellendorffi ''Elaphe moellendorffi'', commonly called the flower snake or Moellendorf's icrat snake, is a species of snake in the family Colubridae. The species is endemic to southeastern Asia. Etymology The specific name, ''moellendorffi'', is in honor o ...

''. As of May 2020, this species has not yet been assessed for the

IUCN Red List of Threatened Species The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...

References

nonggangensis Amphibians described in 2013 Amphibians of China Amphibians of Vietnam {{rhacophoridae-stub