Care sheet
Natural History and Behavior By Derek Wong and Roman Moniz
Of the many species of geckos endemic to Australia, those of the genus Nephrurus have generated much interest in herpetoculture. Currently, nine species of Knob-tailed geckos are recognized and they are generally widespread across the continent throughout sub-humid to arid biotopes. They are differentiated from most other Diplodactyline geckos by their massive heads, short stocky bodies, slender limbs, and, of course, their knobbed tails. The genus can be further divided into two types: rough-skinned and smooth-skinned. These two groups differ in both skin texture, as well as habitat preferences, with the rough-skinned utilizing rocky habitats, while the smooth-skinned residing in more humid burrows instead.
This care sheet will focus mainly on the Centralian or Rough Knob-tailed Gecko (Nephrurus amyae). Nephrurus amyae is distributed throughout most of the northern portion of Australia where it usually inhabits rocky outcroppings and crevices on a sandy substrate. They prefer dryer shelters than those of the smooth-skinned species and appear to be able to withstand more arid conditions as well. As with most nocturnal geckos, Nephrurus amyae are most active one or two hours after sunset. During that time, they forage for prey items including insects, arthropods, and even other terrestrial geckos.
This species also exhibits very interesting behaviors. When threatened, they will raise their body off the ground, inflate their lungs, and rhythmically raise and lower their body. If aggravated even further, they will not hesitate to lunge forward and bite with their powerful jaws. Often, they will also emit short squeals and hisses if they are disturbed to a lesser extent. Their tails wiggle wildly during feeding and threat displays. It has been suggested that Nephrurus in general use their knob-tails to attract prey, but its exact function is still under debate. Another notable behavior that this species displays in order to escape notice is to fling sand over themselves to blend into their environments. It is often hard to distinguish these geckos from these sandy earth upon which they dwell until some sign of movement is observed.
Description
Nephrurus amyae is the largest species of knob-tailed geckos with robust females attaining a snout-vent-length of 5 inches and total weight of 65g. Males are generally smaller and are otherwise similar in appearance build. They possess a large and intricately marked head. Compared to their head and body, their limbs and short tail are relatively skinny. Their bodies are covered with large spines that are usually lighter in color than their overall red, orange, and/or brownish coloration. Lighter transverse bands may also be present in certain individuals. Many rough knob-tailed geckos also have a reticulated pattern of dark brownish lines descending down their backs that extend to the ventral portion of their bodies. The underside of these geckos is a uniform whitish color and consists of smooth scales.
Captive Husbandry
Knob-tail geckos are not the most demanding captives, but they do have some specific requirements. The floor of the enclosure should be covered with a thin layer of fine sand that does not have to be too deep since this species is not an avid digger. Shelter can be provided in the form of a hidebox (usually an inverted plant saucer with a hole cut in it) or a pile of rocks glued together if a more naturalistic appearance is desired. The shelter should have a height high enough so that the gecko can comfortably stand upright once inside. An additional hiding area should be provided on the cooler end of the enclosure as well so that the rough knob-tail can thermoregulate without feeling exposed or threatened. Heat is provided in the rear portion of the enclosure by heat tape and is thermostatically set to a temperature of 82°-86° degrees Fahrenheit. As mentioned before, Nephrurus amyae prefer drier conditions so the substrate and hideboxes do not need to be kept moist. Instead, their enclosures are sprayed with water once or twice a week in the warmer months, and less often during the cooler times of the year. These geckos are also aggressive feeders and they accept a wide variety of prey including: crickets, mealworms, waxworms. If kept under optimal conditions, this remarkable gecko can attain adult size within 12 months.
Breeding
Captive reproduction of Nephrurus amyae is fairly straightforward. The female should have good body weight (45g or over) and should be at least a year old (preferably 18 months of age). The animals should be cycled before breeding with a cooling period of 3 months with reduced feeding, watering, and heat. After the winter cooling period, the animals should be fed and watered with increased frequency and the heat raised back up to 80-82 degrees Fahrenheit. A single pair should be placed together in an enclosure with a minimum floor space of one foot by two feet with a moist container of sand at a depth of at least five inches. Eggs can be seen through the belly of the females as they begin to form. The female will become very restless shortly before oviposition. A large amount of sand will be displaced by the female after laying and the eggs are usually buried at the bottom of the laybox. The eggs should be promptly removed and placed in an incubation medium (50:50 ratio of medium to water by weight). They are incubated at a temperature of 80-82 degrees Fahrenheit and hatch between 80-120 days. The young are reared individually in a manner similar to adults.
Note: These are the methods that we have personally used to successfully hatch, raise, and maintain these unique geckos. Others may disagree with some of the information provided in this care sheet, but we are simply stating what has worked for use. Thank you for taking the time to read this care sheet and we hope that it was helpful!
