Copyright 2006 author and Reptiles Australia
(Full article available in Vol 2 no 3).


CAPTIVE BREEDING AND MAINTENANCE OF
ROUGH KNOB-TAILED GECKOS
Nephrurus amyae and N. asper.
.


Robert Porter



CAPTIVE HUSBANDRY

As a reflection of the arid and severe characteristics of their natural habitat, both
N. amyae and N. asper are tough and hardy captives. As long as temperature extremes, especially at the upper end, are avoided, there is no reason to believe these geckos would not happily survive in excess of 20 years in captivity.

Although normally solitary in the wild, they appear to be relatively tolerant of other specimens housed in the same enclosure, even two males may be maintained together with or without females in some cases. Ideally, a group of a pair or three geckos (one male and two females) would be housed together. These may be successfully kept in one enclosure all year around, with breeding occurring regularly every year. However, some keepers believe they achieve better breeding success if sexes are kept apart for most of the year and simply introduced for breeding at the appropriate time.

An enclosure measuring around 60 x 30 x 30cm will adequately house a pair of
N. asper, a little larger for a trio. For N. amyae a bigger enclosure is required, say 75 x 30 x 30 for a pair 100 x 30 x 30 for a trio. All knob-tails are terrestrial lizards so no vertical height is required. In fact, if a cage with relatively smooth sides is used, e.g. a glass aquarium, no lid is required if the sides are over about 20cm as their robust built rather inhibits any agile movements such as jumping.

Good ventilation is essential. Most of the top of the enclosure should either be open or covered with mesh to permit efficient air circulation. Ideally, this would be combined with some mesh vents around the enclosure sides nearer the base. This will provide an excellent airflow, the warmer air leaving through the top being replaced by cooler fresh air entering through the vents at the bottom.

Fine sand, such as red desert, beach or plasterer’s sand make ideal substrates. They are cheap, readily available and easy to keep clean. A layer of approximately 4cm is provided for rough knob-tails. They are not avid burrowers (unlike the smooth species) as long as other shelter is provided. Some keepers maintain their rough knob-tails on a paper substrate quite successfully (Wagner & Lazik, 1996) and this is certainly better for hygiene purposes. However, I prefer a more natural cage covering and this also reduces cage maintenance. Once a week any droppings are removed from the sand surface, a task taking about a minute for each enclosure. Once every 2–3 months the substrate is totally replaced.

Other furnishings include a glass water dish approximately 3cm in diameter and 2cm deep and two or three up-turned flower pot saucers of appropriate size with an entry hole cut in one side. A small amount of water is poured onto the sand on one side of one of the pot saucers once per week. This provides a moist, humid refuge if required by the animals. Sufficient water is added so that the sand almost dries out within the next 4-5 days.

As well as a low wattage heat pad underneath one end of the enclosure, a 25 or 40 watt incandescent light bulb is also provided at the same end. The combination of these two will produce a heat gradient ranging from 32–33C at the hottest point, down to mid to low 20’s at the cooler end. In winter temperatures can be safely lowered a further 10–12C and this cool period is important to ensure successful reproduction the following spring. Although ultraviolet light is probably not essential to these animals, a Reptisun 5.0 tube, controlled by a timer, is positioned 30cm above the substrate surface. This provides a strong, natural photoperiod, which is adjusted seasonally, as well as offering potentially beneficial ultraviolet light. The lizards are occasionally seen active during the day, especially
N. amyae.
Feeding
Knob-tails are not fussy eaters. Almost any suitably sized insect is a potential food item. My animals are maintained totally on a diet of cricket, gut-loaded with rodent pellets and fresh vegetables. Cockroaches, grasshoppers, mealworms, pink mice and even other small lizards would all be readily accepted. Feeding for adults takes place 2–3 times per week during the warm months, once a month during cooler times.

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