About Nephrurus levis De Vis, 1886
Nephrurus levis De Vis, 1886 is a robust, medium-sized gecko with a large triangular head. It has a short, flattened, carrot-shaped tail that ends in a knob. This tail can be shed through autotomy to distract predators, but unlike many other lizards, this species only has one cleavage point at the base of the tail, meaning the entire tail must be sacrificed when it is shed. It has long slender limbs, non-retractile claws on its digits, and the outermost digit is opposable. This gecko has vertically slit ears located at the widest part of its head, and very large eyes with vertical pupils. On its dorsal side, its base colour generally ranges from pinkish-grey to purplish-brown, with a unique pattern of darker and lighter spots, bars, or lines. Its underbelly is white. The body and tail of N. levis are covered in pale and dark tubercles that often form bands. The species epithet levis, meaning smooth, refers to the smoothness of this species' skin compared to N. asper, whose epithet asper means rough. Generally, N. levis measures 8–10 centimetres (3.1–3.9 in) from snout to vent. An original, undropped tail is usually around 2 centimetres (0.79 in) long. Males are typically smaller than females, and both sexes can live up to 15 years in captivity. Smooth knob-tailed geckos are distributed across the arid interior of Australia. They occur in all Australian mainland states and territories except Victoria and the Australian Capital Territory. They are widespread across South Australia, ranging as far south as Adelaide. Their range extends as far north as Tennant Creek in the Northern Territory, as far east as Bourke in New South Wales, and as far west as Western Australia's coastline. The smooth knob-tailed gecko occupies a wide range of habitats, including arid areas, semiarid areas, open woodland, arid scrubs, spinifex-covered deserts, sand-plains, and dune-fields. The species' breeding season falls between October and March, the warmer months of the year. Females can produce 6 or 7 clutches of eggs per breeding season. When ready to breed, receptive females display specific behaviours that allow males to mate with them. Non-receptive females will either stand their ground and attack males, or run away from approaching males. After mating, egg deposition occurs roughly 4 to 6 weeks later, though this interval can take up to 9 weeks. Eggs then take approximately 6 to 8 weeks to hatch. Most clutches contain 2 eggs, single-egg clutches are rare.
