| Preliminary care sheet for Gonocephalus and Acanthosaurus species, with special reference to G. chameleontinus and A.capra.
The Genus Gonocephalus contain 17 species. G.belli, G.chamaeleontinus, G.grandis, G.kuhli, G.megalepis, G.semperi, G.beyschlagii, G.denzeri, G.interruptus, G.lacunosus, G.mjoebbergi, G.sophiae, G.borneensis, G.doriae, G.klossi, G.liogaster, G.robinsonii.
Acanthosaurus are currently listed as 6 species, A.armata, A. capra, A.coronata, A.crucigera, A. lepidogaster, A.nataliae. The species nataliae, I believe only described ( Orlov, Nguyen & Nguyen) 2006, beautifull pictures in the excellent publication Terralog by Ulrich Manthey, Agamid Lizards of Southern Asia, Draconinae, Edition Chimaira. See further reading.
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| Distribution: |
| Gonocephalus occur from Vietnam, Thailand, down to the Malayan Peninsula, Philippines, Indonesia, Borneo, Java and Sumatra. From Wallace’s line east, the Genus Hypsilurus replaces Gonocephalus, which contain 13 species range from Irian Jaya /New Guinea, and the many small islands of Micronesia, Melanesia and Australia. Hypsilurus were originally part of the genus Gonocephalus and look very similar. (Alfred Russell Wallace noticed the abrupt contrast between the animals occurring on the Island of Bali and Lombok only 15miles across the Makassar strait at its closest point in 1883).
The current 6 species of Acanthosaurus occur in Thailand, Malayan Peninsula, Pulau, Tioman, Penang, Singapore, Anamba Islands, Kampuchea, Laos, Vietnam, Cambodia, and Southern China.
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| Housing: |
| Habitat)
These Agamid lizards are both rainforest species and both are associated with rivers, streams and moving water. Some are more mountain than others and this will need some research to find local temperatures in the wild, as a guide to captive husbandry temperatures. They are at the same time extremely arboreal. Acanthosaura seem much more sensitive to higher temperatures than Gonocephalus.
Housing
These agamas need a fairly large cage which should provide a height of 3 to 4 feet and plenty of areas to hide from one another, (visual barriers). Horizontal branches are less important than vertical ones. (Rogner, English edition 1976), suggests vertical branches of wood, 5 to 10 cm diameter for Gonocephalus, in the centre of the cage. Dense planting of robust bushy plants are also recommended. Both species will sleep on these at night. Live plants are better than artificial ones but will need to be strong enough to withstand the weight of the lizards. The main advantage is they help to maintain the humidity better. Moving water is crucial. Humidity 85 to 98%. The vivarium should be brightly lit in one third of the area, leaving the remainder shady where animals can hide. Using an airstone in the water supple is the minimum provision to attract the animals to drink. Better still are a filtered waterfall or small stream system. These will be more effort to set up but well worth the trouble. In many ways these dragons demand a similar water requirement to chameleons. As they are nearly always found near moving water, new imports will often not drink until they see a rainfall system spraying onto leaves and stones or pumped into a mini pool area which is recycled and filtered back to the same pool.
Substrate can consist of a moist peat/coir and sand mix, coir a waste product of the coconut is an excellent product for rainforest setups and I also use it mixed with vermiculite to incubate eggs for some reptiles. Leafmould mixed with good quality loam, sand and peat or coir mix. Make sure that all substrates are free of additives such as fertilisers or pesticides.
These Mountain dragons will normally live in one male to 2 female groups. This is probably the maximum size group to house together.
The commercial waterfall systems are often too difficult to keep clean and could become sources of infection. They often defecate in water so all water will need changing frequently.
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| Heating and Lighting: |
| The lighting of the vivariums can be with TL lamps, which will help to keep the plants alive and UVB tubes to help the agamas to synthesise D3 for good bone developement and calcification of the eggs in females. This in turn should provide the means for maximum use of the all important utilisation of calcium in the diet. Gonocephalus generally seem to prefer higher temperatures than Acanthosaurus which will not take temperatures above 27c. The preferred range of 23-25c being the optimum range. They tend not to actively bask under a heat bulb source.
Gonocephalus prefer a basking daytime temperature of 30-35C in the warm end to 20-26 at the cooler end. This is a good thermal gradient. Night temperatures for both types of dragons can be allowed to drop to 16-18C and is probably beneficial.
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| Hibernation: |
| This would appear to be unnecessary. |
| Food and Water: |
| All types of invertebrates can be offered, such as earthworms, (a favourite), woodlice, giant mealworms, waxworms, (limit these as they can become addictive to the exclusion of anything else), crickets, cockroaches and snails. Some individuals will take fish and pink mice. Water is covered in the housing section. |
| Reproduction: |
| This is at an early stage but Acanthosaurus have been reared from captive born young with few problems other than fatalities through higher temperatures during the summer months. This was solved by setting up a cool room. There is practically no source of Captive bred animals at this stage as all breeding stock originates from fresh imports or gravid female imports laying viable eggs and producing captive born young. I bred some Gonocephalus chameleontinus about 10 years ago but only 2 animals from a clutch of 6 eggs. One of these was raised to sub-adult stage before passing it on due to lack of space at the time.
The hobby has moved on since then and there is a whole range of equipment to allow correct temperature control, UV light, and humidity control, not to mention the increase in feeder insects. These dragons will, like chameleons soon be available in small numbers to specialist breeders and enthusiasts and probably in time to a larger market. Reptiles normally do well in captivity and produce relatively large numbers of young as they are generally in nature at the bottom end of the food chain. This gives us an opportunity to adapt them to our much more sophisticated Vivariums, Terrariums of the 20th Century.
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| Any other hints or tips: |
| Further reading and comments.
Amphibians and Reptiles of Peninsular Malaysia and Thailand, An Illustrated Checklist. Tanya Chan-ard, Wolfgang Grossmann, Andreas Gumprecht, Klaus Dieter Schulz. ISBN 3-9806813-0-0
Agamid Lizards, Ulrich Manthey and Norbert Schuster TFH 1996. (German translation). Reasonably priced. Good range of pictures and useful text. Good photographs of Acanthosaurus and Gonocephalus. ISBN 0-7938-0128-1
Lizards Volume 1 of 2 volumes, Manfred Rogner, Krieger translation from German, Nice all round lizard book with sections on vivaria, lighting, feeding, vitamins, reproduction, incubation. Detailed sections on Acanthosaurus and Gonocephalus, as well as many other tree dragons. ISBN 0-89464-972-8 (set 1 & 2). ISBN 1-89464-939-6 (vol 1)
Herpetofauna of Vietnam Edition Chimaira 2009 ISBN 978-3-89973-462-1. Nygen Van Sang, Ho Thu Cuc, and Ngiyen Quang Truong. English. Complete check list with photos and some specific location data. Classic reference book.
Guide to Philippine Flora and Fauna Volume X. Amphibians and Reptiles, Prof. Angel C Alcala, Natural Resources Management Centre, University of the Philippines. 1986. ISBN 971-1026-28-7
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