Argentine Black & White Tegu (Salvator merianae)
The Argentine Black & White Tegu is a large, intelligent and highly active South American lizard. Tegus are powerful diggers, opportunistic omnivores and capable problem-solvers that require considerably more space, environmental complexity and food than most commonly kept lizards.
Well-managed individuals can become accustomed to routine keeper interaction, but they should not be regarded as “scaly dogs”. Their behaviour, strength and husbandry requirements remain those of a large reptile.
Quick Facts
Scientific name: Salvator merianae
Common names: Argentine Black & White Tegu, Argentine Giant Tegu
Family: Teiidae
Distribution: South America, including Argentina, Brazil, Paraguay, Bolivia and Uruguay
Lifestyle: Primarily terrestrial and fossorial
Activity: Diurnal
Adult size: Commonly approximately 90–140 cm, with males generally becoming larger and more heavily built than females
Lifespan: Commonly 15–20+ years in captivity
Diet: Omnivorous
Reproduction: Oviparous (egg-laying)
Experience level: Intermediate to advanced
Taxonomy
The Argentine Black & White Tegu was historically classified as:
Tupinambis merianae
It is now placed in the genus Salvator and recognised as:
Salvator merianae
Older books and websites may therefore still use the former scientific name.
This care sheet specifically covers Salvator merianae. Other species commonly called “tegus” may have different dietary, environmental and adult-size requirements.
Enclosure Size
Argentine Tegus are large, extremely active lizards.
Adult accommodation should be planned according to the size and sex of the individual.
As practical starting points:
Adult female: approximately 240 × 120 × 120 cm or larger
Large adult male: approximately 300 × 150 × 150 cm or larger
More space is strongly encouraged whenever possible.
The enclosure should allow the tegu to:
- Walk and turn freely
- Explore
- Dig
- Burrow
- Fully stretch out
- Thermoregulate
- Bask with its entire body
- Retreat completely from view
Juveniles can be maintained in smaller accommodation provided adequate environmental gradients and enrichment are maintained.
Adult housing should be planned before acquiring a juvenile.
Enclosure Security
Tegus are powerful and persistent animals.
Enclosures should have:
- Strong construction
- Secure locking doors
- Protected ventilation
- Secure lighting and heating equipment
- Protected electrical cables
- Strong furnishings
- No exploitable gaps
Tegus can dig, push and investigate weak points repeatedly.
A poorly secured enclosure should never be relied upon simply because the animal has not previously attempted to escape.
Substrate & Digging
Digging is an important natural behaviour.
Adults should be provided with a substantial depth of suitable substrate — generally at least:
20–30 cm
where enclosure design allows, with deeper areas encouraged.
Suitable substrates may include mixtures containing:
- Chemical-free topsoil
- Reptile-safe soil
- Play sand
- Coconut fibre
- Leaf litter
The substrate should be capable of holding burrows and maintaining deeper moisture without becoming waterlogged.
Surface conditions can vary while deeper layers remain moderately moist.
Avoid:
- Cedar
- Strongly aromatic wood products
- Excessively dusty substrate
- Permanently saturated substrate
Furnishing & Enrichment
Tegus are highly exploratory animals and should not be maintained in barren accommodation.
Provide:
- Deep digging areas
- Large hides
- Cork bark
- Heavy logs
- Stable rocks
- Leaf litter
- Visual barriers
- Different substrate depths
- Food-searching opportunities
- Novel safe objects
- Robust climbing or elevated structures where appropriate
Furnishings must be strong enough to withstand a large tegu pushing, digging beneath or climbing over them.
Enrichment should encourage:
- Exploration
- Foraging
- Digging
- Exercise
- Problem-solving
- Choice
Temperature
Tegus require access to a substantial, high-temperature basking area.
Basking Surface
Approximately:
45–55°C
The entire animal should be able to fit beneath the basking zone rather than having only a small part of the body heated.
Warm Ambient Area
Approximately:
28–32°C
Cool Area
Approximately:
23–27°C
Night
A nighttime reduction to approximately:
18–23°C
is generally appropriate for healthy animals outside controlled seasonal dormancy.
These figures are useful starting points rather than rigid values.
Basking Area
A large adult tegu requires a broad basking zone, not one small extremely hot spot.
Multiple overhead heat lamps may be necessary to heat the entire body evenly.
The basking surface should allow the animal to choose between slightly different temperatures.
Measure surface temperatures with an infrared thermometer.
Monitor ambient temperatures separately using reliable digital thermometers.
Heating
Overhead heating is generally most appropriate.
Suitable systems may include:
- Halogen flood lamps
- Other appropriately designed basking lamps
- Supplementary guarded heating where necessary
All heat sources must be appropriately controlled and installed safely.
Lighting and heating equipment must be inaccessible to the tegu or securely protected.
Tegus are strong enough to damage poorly secured equipment.
Lighting
Argentine Tegus are diurnal and benefit from a bright daytime environment.
A combination of:
- Basking lamps
- UVB
- Bright visible-spectrum lighting
can help create an appropriate daytime environment.
Provide approximately:
12–14 hours of light during the active season
with seasonal variation where appropriate.
The enclosure should still contain shaded areas and retreats.
UVB
High-quality UVB is an important part of modern Tegu husbandry.
Aim for approximately:
UVI 3–4 across the primary basking zone
with progressively lower exposure away from the basking area.
The tegu must also have access to:
- Lower UV exposure
- Complete shade
- Secure dark retreats
Do not select a UVB lamp solely according to whether the package says 10%, 12% or 14%.
Actual UVI depends on:
- Lamp type
- Reflector
- Distance
- Mesh or screening
- Installation
- Lamp age
A suitable UV meter provides the most reliable method of measuring actual exposure.
Humidity
Argentine Tegus generally benefit from relatively humid conditions.
Approximately:
60–80%
provides a useful general range, with natural daily variation.
Humidity may rise overnight and fall during the daytime.
The objective is not to maintain every surface permanently wet.
Provide:
Appropriate humidity + deeper substrate moisture + ventilation + areas of dry surface substrate
A humid retreat can provide access to a particularly moist microclimate.
Humid Retreat
Provide a secure humid retreat containing suitable moisture-retaining substrate.
This can be particularly useful during shedding.
Suitable materials may include:
- Moist soil
- Coconut fibre
- Sphagnum moss
The material should remain moist rather than waterlogged.
Check humid retreats regularly for contamination and mould.
Water
Fresh drinking water must always be available.
Provide a large, stable water container that the tegu can easily access.
Many individuals will voluntarily soak.
The container should be:
- Easy to enter and exit
- Stable
- Easy to clean
- Large enough to provide meaningful access to water
Tegus frequently contaminate their water with substrate and waste, so it may require frequent cleaning.
A purpose-built water area with drainage can make maintenance considerably easier in large adult enclosures.
Diet
Argentine Black & White Tegus are omnivorous.
A varied diet is essential.
Suitable animal foods include:
- Appropriately sized whole prey
- Insects
- Snails
- Eggs in moderation
- Appropriately formulated reptile diets where useful
- Other nutritionally appropriate animal foods
Suitable plant foods include a varied selection of:
- Leafy greens
- Squash
- Courgette
- Peppers
- Other suitable vegetables
- Berries
- Melon
- Papaya
- Other suitable fruits
Fruit should form a smaller part of the captive diet rather than dominating it.
Juvenile Diet
Growing juveniles naturally consume proportionally more animal matter than mature adults.
Suitable foods include:
- Crickets
- Locusts
- Cockroaches
- Other suitable feeder insects
- Appropriately sized whole prey
- Small amounts of suitable plant material
Variety is preferable to dependence on one food item.
Growing animals require careful attention to calcium, UVB exposure and overall nutritional balance.
Adult Diet
Adult Argentine Tegus remain omnivorous.
A useful captive diet should contain a varied mixture of:
- Invertebrates
- Appropriate whole prey
- Vegetables
- Greens
- Smaller amounts of fruit
There is no need to force every meal into an exact fixed protein-to-plant percentage.
Diet should instead be assessed across time for:
- Variety
- Nutritional balance
- Calcium content
- Energy density
- Body condition
Avoid excessive quantities of:
- Rodents
- Fatty meat
- Fruit
- Highly processed foods
These can contribute to obesity.
Whole Prey
Appropriately sized whole prey can be nutritionally valuable because it provides:
- Muscle tissue
- Bone
- Organs
- Connective tissue
Suitable examples may include appropriately sized rodents and other nutritionally appropriate whole vertebrate prey.
Whole prey should form part of a varied diet, not necessarily every meal.
Routine live vertebrate feeding should be avoided.
Feeding Frequency
A useful starting point is:
Hatchlings: approximately 5–6 feeding days per week
Juveniles: approximately 4–5 feeding days per week
Subadults: approximately 3 feeding days per week
Adults: approximately 2–3 feeding days per week
These are starting points rather than rigid schedules.
Adjust according to:
- Age
- Growth
- Activity
- Season
- Reproductive status
- Portion size
- Body condition
Supplementation
Supplementation depends on the overall diet.
Insect-heavy meals generally require appropriate calcium supplementation.
A varied diet containing whole prey provides considerably more naturally balanced minerals than boneless meat alone.
Supplementation should take into account:
- UVB exposure
- Whole-prey intake
- Insect intake
- Age
- Reproductive status
- The formulation being used
Avoid indiscriminate over-supplementation.
Foods to Avoid
Avoid feeding:
- Highly processed human foods
- Seasoned foods
- Foods containing excessive salt
- Large quantities of fatty meat
- Large quantities of fruit
- Wild prey exposed to pesticides or toxins
- Inappropriately large whole prey
Boneless muscle meat should not dominate the diet because it is nutritionally incomplete.
Obesity
Obesity is a significant problem in captive tegus.
Signs of excessive body condition may include:
- Excessive fat around the abdomen
- Very thick jowls beyond normal mature-male development
- Fat deposits around the limbs or tail base
- Reduced mobility
- Poor muscle definition
- Low activity
Regularly monitor:
- Body weight
- Body condition
- Activity
- Food intake
An adult tegu should be robust and muscular without being excessively heavy.
Foraging & Feeding Enrichment
Not every meal needs to be presented in a bowl.
Food can sometimes be:
- Hidden safely within the enclosure
- Distributed between several locations
- Offered through suitable puzzle feeders
- Presented in ways that encourage natural searching behaviour
Always ensure food remains hygienic and cannot become lost and spoiled within the substrate.
Handling & Keeper Interaction
Argentine Tegus can become accustomed to predictable human interaction, but daily forced handling is not required to create a manageable animal.
Build trust through:
- Predictable routines
- Calm enclosure maintenance
- Food-independent interaction
- Allowing voluntary approach
- Gentle handling when appropriate
- Respecting retreat behaviour
Avoid repeatedly chasing, grabbing or restraining the animal unnecessarily.
A frightened adult tegu is capable of:
- Powerful bites
- Scratches
- Tail strikes
Respect the animal’s body language.
Free-Roaming
Supervised exploration outside the enclosure can provide useful exercise and enrichment.
However, a normal human room is not a replacement for an appropriately heated, humid and illuminated enclosure.
Free-roaming should be:
- Supervised
- Temporary
- In a secure area
- Away from other pets
- Free from toxic plants and chemicals
- Free from small objects that could be swallowed
The animal must still have appropriate access to its normal enclosure conditions.
Behaviour
Tegus are highly inquisitive and may:
- Dig
- Investigate objects
- Move furnishings
- Search for food
- Establish preferred retreats
- Alter activity seasonally
Individual temperament varies considerably.
Juveniles may be more defensive or flighty than established adults.
Behaviour may also change during sexual maturity and reproductive periods.
Shedding
Tegus normally shed in patches rather than removing the skin in one complete piece.
During shedding:
- Maintain appropriate hydration
- Maintain suitable humidity
- Provide a humid retreat
- Provide textured surfaces
- Ensure adequate nutrition
Do not routinely pull attached shed from the animal.
Persistent retained shed, particularly around toes or tail tips, can cause injury and should be addressed.
Seasonal Dormancy
Argentine Black & White Tegus originate from regions with pronounced seasonal changes.
Some individuals may naturally reduce:
- Activity
- Feeding
- Basking
- General movement
during cooler periods.
This seasonal dormancy is commonly referred to as brumation.
Captive behaviour varies considerably depending on:
- Individual
- Age
- Origin
- Environmental conditions
- Captive history
Do not assume that every tegu must be deliberately forced into brumation.
Planned Brumation
Controlled brumation is primarily relevant to experienced keepers and breeding programmes.
Only healthy animals in suitable body condition should undergo deliberate cooling.
Before planned brumation:
- Ensure digestion is complete
- Confirm good body condition
- Reduce environmental conditions gradually
- Maintain access to water
- Monitor the animal
Animals that lose excessive weight or appear unwell require reassessment.
Inexperienced keepers should research the process thoroughly before attempting controlled brumation.
Cleaning
Spot-clean:
- Faeces
- Urates
- Spoiled food
- Heavily contaminated substrate
as soon as practical.
Water containers may require very frequent cleaning because tegus commonly defecate or drag substrate into them.
Deep substrate does not necessarily need to be completely replaced on an arbitrary schedule if it remains clean and appropriately maintained.
Quarantine
New tegus should be quarantined away from established reptiles.
During quarantine monitor:
- Appetite
- Weight
- Faeces
- Shedding
- Respiration
- Activity
- Skin condition
- External parasites
Use separate equipment wherever practical.
Veterinary faecal examination may be appropriate, particularly for animals with uncertain histories.
Common Health Concerns
Potential health problems include:
- Metabolic bone disease
- Obesity
- Nutritional imbalance
- Retained shed
- Thermal burns
- Respiratory disease
- Internal parasites
- External parasites
- Mouth disease
- Reproductive complications
- Injuries associated with inappropriate housing
Persistent abnormalities should be assessed by a suitably experienced reptile veterinarian.
Metabolic Bone Disease
Metabolic bone disease can occur when calcium metabolism is disrupted.
Risk factors include:
- Inadequate UVB exposure
- Poor calcium intake
- Nutritionally unbalanced diets
- Inappropriate supplementation
Possible signs include:
- Weakness
- Tremors
- Limb deformities
- Swollen limbs
- Soft or abnormal jaw structure
- Difficulty walking
- Fractures
Prevention depends on appropriate UVB, diet and supplementation.
Suspected metabolic bone disease requires veterinary assessment.
Sexing
Adult males generally develop:
- Larger heads
- More pronounced jowls
- Heavier overall build
- More obvious femoral/preanal structures
Females generally remain smaller and less heavily built.
Young tegus can be more difficult to sex reliably.
Breeding
Argentine Black & White Tegus are oviparous.
Breeding should only involve:
- Healthy mature animals
- Correctly sexed individuals
- Appropriate body condition
- Adequate space
- Suitable nesting facilities
- Planning for offspring
Seasonal dormancy can play an important role in reproductive cycling.
Nesting
Females may construct substantial nests and should have access to deep, suitable nesting substrate.
A reproductive female may become more defensive around her nest.
Disturbance should be minimised where practical.
Clutch size varies considerably but approximately:
15–35 eggs
is common, with larger clutches possible.
Incubation
Eggs are generally incubated at approximately:
28–30°C
Incubation commonly lasts around:
55–75 days
depending on temperature and other conditions.
Eggs should not be routinely rotated after laying.
Incubation medium should retain appropriate moisture without leaving the eggs sitting in free water.
Hatchlings
Hatchlings should be provided with:
- Secure accommodation
- Deep enough substrate for digging
- Multiple hides
- Appropriate basking temperatures
- High-quality UVB
- Appropriate humidity
- Fresh water
- A varied diet
Young tegus grow rapidly but should not be deliberately overfed to maximise growth.
Steady development with appropriate skeletal and muscular growth is preferable.
Lifespan & Long-Term Commitment
Argentine Black & White Tegus commonly live for 15–20 years or longer.
A small hatchling can develop into a powerful lizard exceeding one metre in length.
Before acquiring one, consider:
- Adult enclosure space
- Heating and lighting costs
- Large quantities of substrate
- Food costs
- Veterinary access
- Long-term holiday and emergency care
- Safe adult handling
Adult requirements should be planned before purchase.
Final Husbandry Principles
Successful Argentine Black & White Tegu husbandry depends on:
- Very large secure accommodation
- Deep digging substrate
- A broad high-temperature basking zone
- High-quality measured UVB
- Bright daytime lighting
- Appropriate humidity without waterlogging
- Constant access to fresh water
- A varied omnivorous diet
- Prevention of obesity
- Extensive environmental enrichment
- Calm, voluntary keeper interaction
- Seasonal awareness
- Quarantine and health monitoring
- Long-term planning
A well-designed Tegu enclosure should allow the animal to make meaningful choices about temperature, light, humidity, shelter, digging, exploration and activity.
IMPORTANT INFORMATION:
This care sheet provides general husbandry guidance and does not replace species-specific research or veterinary advice. Individual requirements may vary.
If you have concerns about an animal’s health or care, consult a suitably experienced exotic or invertebrate veterinarian.
Information correct at the date of publication.
reptilecommunity.com | Revised: August 2026