Gekko (Japonigekko) qiannanensis, a new karst-adapted gecko (Squamata, Gekkonidae) from southern Guizhou, China

Karst landscapes, which are characterized by their complex terrain, foster exceptionally high species diversity. During recent field surveys in Qiannan Buyi and Miao Autonomous Prefecture, Guizhou Province, China, a new karst-adapted gecko species was discovered. Using an integrative approach combining molecular and morphological analyses, it is described here as Gekko qiannanensis sp. nov.

Phylogenetically, it clusters within a well-supported clade of the subgenus Japonigekko that includes the karst-adapted G. fengshanensis, G. liboensis, G. kwangsiensis, G. paucituberculatus, and the dry-hot valley species G. tesselatus. Morphologically, it can be distinguished from all known species in Japonigekko by a combination of the following traits: moderate body size, with snout – vent length 65.4–82.9 mm in adult males and 77.7–91.7 mm in adult females; two enlarged postmentals; nares in contact with the rostral, internasal absent; subdigital lamellae: fourth fingers 14–16, first toes 9–11, and fourth toes 14–17; moderately developed toe webbing, originating proximal to subdigital lamellae; interorbitals 28–38; midbody scale rows 134–155; ventral scale rows 42–49; precloacal pores 10–11 in males; a single postcloacal tubercle on each side; dorsum earth gray, with six dirty-white bands between the nape and sacrum.

Notably, the new species can be distinguished from its karst-adapted congeners by its moderately developed toe webbing. The discovery of G. qiannanensis brings the number of recognized species in Japonigekko to 42 globally, of which 28 are now recorded from China. This finding highlights the role of karst habitat fragmentation in driving allopatric speciation and underscores the rich but still incompletely documented herpetofaunal diversity of South China’s karst regions.