Scientific name: Tupinambis meriane
Sexing and characteristics:
The Argentinian black and white tegu is a large and robust terrestrial lizard. The body is muscular, offset by powerful long nailed limbs designed for digging. The neck is quite short, and the tail accounts for more than 65% of the total body length. These tegus have a forked tongue and beaded skin which has linear black and white striping – or yellow/green and black striping as juveniles.
Mature males are quite easily distinguished from females. Males can commonly reach 4- 4 1/2 ft in
length, whilst females tend to average out at about 3 ft. Males have a stockier build than females, and large jowls become evident at the cheeks as they mature. Young tegus can be probed. This can be traumatic, as can popping the hemipenes. Sex is often revealed when a male develops cloacal spurs and possibly everts the hemipenes when defecating.
These tegus can generally be found in savannah and grassland at the edge of tropical rainforests in Eastern and Central South America.
The Argentinian black and white tegu is the largest tegu in existence. Males can reach 4 to 4 ½ ft in length, while females tend to average out at about 3 ft.
Substrate and water needs:
In their natural habitat, these tegus spend much of their time in burrows, and their bodies are designed for digging and burrowing. A substrate which allows for a degree of digging, that is also capable of holding adequate moisture, is what is necessary. Many keepers opt for mulch (e.g. cypress mulch), soil or bark type beddings.
Cedar and pine type beddings should be avoided as they are toxic to reptiles.
Fresh water should always be available, ideally in a shallow dish large enough for the tegu to submerge itself in.
Lighting and UVB:
UVB light is essential to help your lizard produce Vitamin D3 and break down calcium. A 12 hour on/12 hour off cycle is recommended by this keeper when not attempting to breed. Always use a bulb guard in conjunction with any lighting fixtures inside the vivarium to avoid burns to your animal.
Temperatures and humidity:
A high basking spot of 100-115 degrees Farenheit is recommended for this species, along with an ambient temperature of 82-86. A nightime fall into the 70’s is recommended, as is a winter cooldown. Temperature guns and/or in cage thermometers placed at various points throughout your lizard’s housing will help you achieve and maintain adequate temperatures.
To achieve these temperatures, several heating devices can be used such as
- Basking/infrared bulbs
- Ceramic bulbs
- Reptile radiators
The choice of heating system used is a matter of personal choice, however in ALL cases a thermostat should be used in conjunction with the heater in order to avoid burns to the animal and danger of fire.
Tegus are natural bulldozers and are in danger of pulling up heatmats, as well as soaking them. For these reasons, heatmats on floor level are not recommended by this keeper.
These lizards are terrestrial and, as such, do not require height in a housing system. Smaller vivariums will be sufficient for juveniles, but tegus grow large quite rapidly! An adult male will require a minimum enclosure size of 6ft (length) 2-3ft (width) x 2ft (height), and may need to be larger, depending on the size of your adult and how often they get to roam outside their enclosure.
Argentinian tegus are pure bulldozers, and any flimsy decorative work in their enclosure will be made short work of! Large secure pieces of bark are useful both for basking upon and hiding behind. In this keeper’s opinion, most lizards appear more settled when they have somewhere to hide. Be creative, and preferably fix whatever you use well in place!
Rocks can help with nail management, as well as providing a basking spot.
Strictly speaking, this species is omnivorous. However, many adults especially have a preference for a principally carnivorous based diet. Most tegus will feed readily on appropriately sized insects such as crickets, locusts and roaches, mealworms, snails etc. Fruit is accepted by some, but not all tegus, especially as they mature.
Rodents should be fed sparingly as they are high in fat, although most tegus seem to love them! Plain meat such as chicken, fish or ground turkey is a useful food source. Hard boiled eggs and small amounts of high quality cat food are much appreciated occasional treats which should be fed sparingly.
Young tegus require daily feeding, but mature animals should be fed less frequently.
Supplements, nutrition and usage:
A Calcium supplement with a low Phosphorus content should be used to dust food regularly, and a multivitamin supplement (e.g. Nutriball) used at intervals, e.g. once or twice per week. Live insects represent a very high ratio of calcium to phosphorus, but gutloading insects and correct supplementation can help avoid potential problems that may result from this, such as Metabolic Bone Disease.
While tegus have specific husbandry requirements, once these are established from the outset, along with an adequate feeding and supplementation routine, these tegus make for quite hardy captives.
I would recommend a water change every 1 -2 days, spot cleaning as necessary and a thorough clean out and disinfecting every 1 – 2 months. Tegus, although not tidy, are often very clean enclosure inhabitants and will even scratch to be allowed out of their enclosure when they need to relieve themselves.
Some words on this species:
Argentinian black and white tegus are acknowledged by many as one of the best larger lizards to keep in captivity. This is probably due to their reputation as being incredibly intelligent, as well as docile. When human interaction is introduced to a tegu early enough in their life, it seems rare for them not to develop into tame lizards that accept human contact readily. Many believe they show a much greater degree of interaction and bonding with their owners than the majority of other lizards kept in captivity.
In my experience, these lizards make exceptional pets that are very laid back compared to other similar species that are readily available to keepers. Studies suggest that they are capable of recognising and even showing preferred behaviour towards primary carers, something the reptile keeper does not always get to experience. Just watch your fingers at feeding time!
Note: These lizards hibernate in their natural environment and some keepers prefer to hibernate their tegus in captivity, particularly if breeding is to be attempted. Please carry out detailed additional research if you plan to undertake a period of hibernation with your tegu.
Featured Image courtesy of Ariosvaldo Gonzáfoles