Black-eyed Bent-toed Gecko – Cyrtodactylus nigriocularis – Sang, Orlov & Darevsky, 2006

Science name: Cyrtodactylus nigriocularis – Sang, Orlov & Darevsky, 2006

Taxonomic:  Animalia>> Chordata>> Reptilia>> Squamata >> Gekkonidae >> nigriocularis

Species status: Endemic ; IUCN status: CR (Critically Endangered Species)

Description: Physical characteristics:
Cyrtodactylus nigriocularis is a relatively large gecko, with a snout-vent length (SVL) reaching up to 107.5 mm. The species has a flat, wide snout and large, round, black eyes, which are the inspiration for its species name “nigriocularis,” meaning “black-eyed.”
The body is moderately slender and elongated, with well-developed ventrolateral folds running along the sides of the belly. The limbs are moderately long, and the digits are also long, aiding in its climbing ability on rocky surfaces.
The tail is longer than the SVL and features large, undivided subcaudal scales. There are 13–14 upper labial scales and 13–15 lower labial scales, along with 17–21 narrow subdigital lamellae on the fourth toe.
The midbody contains 119–145 rows of scales, and the species lacks large femoral scales.
Coloration and Appearance:
Coloration:
The body is primarily dark brown to black, which helps it blend into the dark cave environments it inhabits. It has dark reticulated patterns along its body, giving it a distinctive appearance in low light.
There are subtle lighter bands or markings that may be present on the body and tail, but the overall coloration is designed for effective camouflage in rocky environments.
The species’ name “nigriocularis” refers to its striking black eyes, which stand out against the rest of its dark body.
Head Pattern: The flat, broad snout and large black eyes are the most prominent features of the head. The head has few visible markings, enhancing its ability to blend into its cave surroundings.
Tail and Limbs: The tail is long and robust, used for balance and climbing on rocky surfaces. The limbs are long, with well-developed digits that allow the gecko to move efficiently through its rocky, uneven habitat.

Distribution and habitat: Elevation: Found at elevations between 50 and 150 meters above sea level.
Area: Endemic to southern Vietnam, Cyrtodactylus nigriocularis is known from Mount Ba Den in Tay Ninh Province. The species inhabits deep rocky caves and forested areas with abundant rock formations.
Habitat: This species is found in caves and forested environments, particularly in areas with limestone karst formations. It is associated with subterranean habitats, often near rocky outcrops and cliffs. These geckos are typically found in dark, moist cave habitats, providing them with shelter and a consistent food source.

Behaviour and ecology: Lifestyle: Cyrtodactylus nigriocularis is a nocturnal species, primarily emerging from its cave habitat at night to hunt for food. It is an agile climber, capable of scaling rocky surfaces with ease, thanks to its long digits and subdigital lamellae.
Reproduction: This species is oviparous, laying eggs in the cracks and crevices of the cave environment. Little is known about its reproductive cycle due to the limited data available on the species.
Diet: It feeds on small insects and other invertebrates found in and around its cave and forested habitats. Its nocturnal behavior aids in hunting for these prey species, which are more active during the night.

Conservation and status: IUCN Red List Category and Criteria: Listed as Critically Endangered under criteria B1ab(iii)+2ab(iii), due to its very limited distribution and habitat degradation.
Threats: The primary threat to this species is habitat loss, particularly due to deforestation and degradation of the rocky cave environments in which it lives. Human activities, such as quarrying and land conversion for agriculture, also pose significant risks to its habitat.
Remarks:
Cyrtodactylus nigriocularis was first described in 2006, and its name is derived from the Latin words “nigri” (black) and “ocularis” (eye), referring to its distinct black eyes. It is a rare and little-studied species, known only from a few localities in southern Vietnam, specifically around Mount Ba Den in Tay Ninh Province. Further research is needed to better understand its population status and ecology.