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Species Profile

Argentine Black and White Tegu

Salvator merianae

Big bands, bold brain, burrow life.
Daniel Lamborn/Shutterstock.com

Argentine Black and White Tegu Distribution

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Invasive Species
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Argentine Black and White Tegu in Rio Claro, Brazil

At a Glance

Wild Species
Also Known As Argentine tegu, black-and-white tegu, common tegu, teiú, teju, tegu lizard
Diet Omnivore
Activity Diurnal+
Lifespan 12 years
Weight 10 lbs
Status Least Concern
Did You Know?

Size: adults commonly ~0.9-1.2 m total length; maximum reports reach ~1.4-1.5 m (tail included).

Scientific Classification

A large, diurnal South American teiid lizard widely known in the pet trade and as an introduced/invasive reptile in some regions (notably Florida).

Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Squamata
Family
Teiidae
Genus
Salvator
Species
merianae

Distinguishing Features

  • Robust, large-bodied tegu with strong limbs and a thick tail
  • High-contrast black-and-white banding/spotted pattern (often more vivid in juveniles)
  • Large head with powerful jaws; forked tongue typical of squamates
  • Primarily ground-dwelling and diurnal; noted for seasonal brumation in cooler months

Physical Measurements

Males and females differ in size

Length
♂ 4 ft 1 in (3 ft 3 in – 4 ft 7 in)
♀ 3 ft 3 in (2 ft 7 in – 3 ft 11 in)
Weight
♂ 12 lbs (8 lbs – 18 lbs)
♀ 7 lbs (3 lbs – 11 lbs)
Tail Length
♂ 2 ft 2 in (1 ft 8 in – 2 ft 7 in)
♀ 1 ft 12 in (1 ft 7 in – 2 ft 4 in)
Top Speed
15 mph
About 24 km/h (reported)

Appearance

Primary Colors
Secondary Colors
Skin Type Salvator merianae has hard reptile scales: small, grainy dorsal scales and larger, smooth rectangular belly scales; thick skin with bony plates under it, giving an armored feel; strong clawed toes for walking and digging.
Distinctive Features
  • Large, heavy-bodied South American teiid lizard (not a monitor lizard/Varanidae): robust torso, thick neck, and powerful limbs; long, muscular tail used for balance and defense.
  • Adult size commonly ~90-140 cm total length; very large individuals reported to ~150-160 cm total length (species-level maxima vary among sources/populations).
  • Diurnal, primarily terrestrial; frequently uses self-excavated or appropriated burrows and will shelter underground (especially for thermoregulation and seasonal inactivity).
  • Seasonal brumation/dormancy tendency in cooler periods (notably in temperate parts of its native range and in introduced populations such as Florida), typically spending extended periods underground.
  • Omnivorous with seasonal diet shifts: consumes invertebrates and small vertebrates as well as fruits and other plant matter; proportion of fruit/plant material often increases seasonally when available.
  • Head typically wedge-shaped with a long, deeply forked tongue (chemosensory foraging); strong jaws; tail distinctly banded and often used in defensive tail-whipping.

Sexual Dimorphism

Sexual dimorphism is evident primarily in overall size and head/jaw robustness. Adult males generally attain greater body mass and develop proportionally larger, broader heads with more pronounced jaw musculature ("jowls"), whereas females are typically smaller and more slender-bodied.

♂
  • Typically larger and heavier-bodied than females at the same age; broader chest/neck and more robust overall build.
  • Broader, more massive head with pronounced jaw musculature/jowls; head width is often an obvious field cue in adults.
  • Femoral pores tend to be more prominent in adult males (as in many squamates), associated with scent-marking/chemical communication.
♀
  • Typically smaller and more slender than adult males; relatively narrower head and less pronounced jaw musculature.
  • Body may appear noticeably broader in the abdomen when gravid (seasonal/temporary), without the male-typical jowling.

Did You Know?

Size: adults commonly ~0.9-1.2 m total length; maximum reports reach ~1.4-1.5 m (tail included).

Mass: large adults often ~3-5 kg; exceptionally heavy individuals can exceed ~7 kg (varies by population and feeding).

Longevity: commonly 15-20+ years in captivity; wild lifespans are typically shorter (pressure from predators, hunting, and climate).

Reproduction: females lay large clutches (often ~20-35 eggs) in a nest chamber and may actively guard it-unusual among many lizards.

Seasonal omnivore: shifts toward more fruit/plant matter in warm months and more animal prey (insects, eggs, small vertebrates, carrion) when available.

Brumation: in cooler seasons they retreat to burrows for weeks to months, greatly reducing activity and feeding.

Physiology standout: during the breeding season, tegus can maintain body temperature several °C above ambient for extended periods ("seasonal endothermy"; reported up to ~10°C above burrow/ambient in studies, e.g., Tattersall et al., Current Biology, 2016).

Unique Adaptations

  • Seasonal endothermy: ability to elevate and stabilize body temperature above ambient during the reproductive season (measured several °C above surroundings; up to ~10°C in published work), improving performance when nights are cool.
  • Robust cranial and jaw musculature: supports an omnivorous diet-crushing insects and snails, tearing carrion, and processing tougher plant material.
  • Forked tongue + strong chemosensory tracking: excellent scent-following for locating hidden eggs, carrion, and buried food sources.
  • Large fat reserves and metabolic flexibility: supports long brumation periods and seasonal food booms (fruiting seasons).
  • Durable osteoderms (small bony deposits in the skin): add protection from bites and abrasion while moving through dense vegetation and burrows.
  • Tail utility: long, muscular tail aids balance and can be used defensively as a striking whip.

Interesting Behaviors

  • Diurnal thermoregulation: long morning basking bouts followed by active foraging during the warmest part of the day.
  • Powerful digging and burrow use: constructs/uses deep refuges for cooling, predator avoidance, and brumation; often reuses the same shelter sites.
  • Seasonal activity cycle: in temperate parts of the range (and in introduced Florida populations), activity drops sharply during cool months as animals remain underground.
  • Opportunistic foraging: searches along edges (forest-grassland, wetlands, human structures) for insects, fallen fruit, bird eggs, and carrion.
  • Nest guarding: females may remain near/at the nest, defending it and maintaining the nest chamber-rare parental investment among reptiles.
  • Learning and problem-solving: in captivity and field observations, tegus show strong exploratory behavior and can learn routines/food cues (one reason they thrive around humans).
  • Invasive ecology behavior (Florida): uses human-made cover (debris, seawalls, drainage areas) and natural burrows, increasing detectability near developed landscapes.

Cultural Significance

The Argentine black and white tegu (Salvator merianae), called the "overo lizard" locally, is hunted for leather and meat, used in folk remedies, common in open habitats and edges, sold as pets, and a well-known invasive in Florida.

Myths & Legends

Local tradition tells of a mythical lizard-like monster, sometimes dog-headed, tied to wild places. Though not actually Salvator merianae, the tale shows big lizards' place in local stories.

The name "tegu" comes from Indigenous languages that used words for big lizards. Indigenous words helped shape local animal names that later entered Spanish and Portuguese.

In River Plate rural tales, the Argentine black and white tegu (Salvator merianae) is seen as a wary, clever fence-line burrower, used in warning stories about stealing eggs and to respect the countryside's hidden life.

Conservation Status

LC Least Concern

Widespread and abundant in the wild.

Population Decreasing

Protected Under

  • CITES Appendix II (listed as Tupinambis spp.; the genus-level listing is commonly applied to Salvator merianae in international trade controls).
  • National/subnational wildlife regulations in range countries (e.g., Argentina has managed/regulated harvest and trade controls for tegu skins in some jurisdictions; implementation and details vary regionally).
  • HUBS (Teiidae / large teiids such as Salvator/Tupinambis): IUCN statuses across the group range from Least Concern to threatened categories in more range-restricted taxa; the most recurrent pressures are habitat loss from agricultural expansion/deforestation and direct exploitation (hunting/skins and pet trade). Notable higher-risk cases within related large teiids tend to be species with smaller ranges and heavier local harvest pressure, whereas wide-ranging generalists (like S. merianae) often remain LC despite localized declines.

Life Cycle

Birth 30 hatchlings
Lifespan 12 years

Lifespan

In the Wild
8–15 years
In Captivity
15–25 years

Reproduction

Mating System Promiscuity
Social Structure Solitary
Breeding Pattern Transient
Fertilization Internal Fertilization
Birth Type Internal_fertilization

Argentine black and white tegu (Salvator merianae) are solitary lizards that meet yearly to breed after winter dormancy. Mating is brief; males fight and they mate with many partners. Females lay one large clutch (about 20–50 eggs) and may guard nests.

Behavior & Ecology

Social Temporary aggregation Group: 1
Activity Diurnal, Matutinal
Diet Omnivore Seasonally abundant fleshy fruit (often taken in large quantities when available; adults commonly shift toward higher fruit intake).
Seasonal Hibernates

Temperament

Generally wary and avoidance-oriented toward threats; may become bold/food-motivated in human-modified landscapes (notably in invasive populations).
Defensive when restrained or cornered (threat postures, lunging/biting, tail-whipping).
Seasonally increased aggression/territoriality in adult males during the breeding season (male-male combat and displacement behaviors).
Females may show heightened defensive behavior associated with nesting sites (nest-area defense/tolerance shifts), with intensity varying among individuals and populations.

Communication

Hissing/forceful exhalation during threat displays Defensive context
Chemosensory communication via tongue-flicking and vomeronasal Jacobson's organ) investigation of scent trails and substrate-borne cues (important for mate tracking and assessing conspecific presence
Scent marking and pheromonal cues from epidermal glands Notably femoral pores typical of teiids) and cloacal secretions; used in sexual signaling and individual/territory assessment (inferred from teiid biology and applied to S. merianae in field/behavioral contexts
Visual threat and assessment displays: raised head/neck, lateral body inflation, tail positioning and tail-whipping; used in agonistic encounters and predator deterrence.
Tactile signals during reproduction and conflict: mounting/neck grasping during mating; biting and physical pushing during male-male combat.

Habitat

Biomes:
Tropical Rainforest Tropical Dry Forest Savanna Temperate Grassland Temperate Forest Wetland
Terrain:
Plains Hilly Coastal Riverine
Elevation: Up to 3280 ft 10 in

Ecological Role

Omnivorous mesopredator, nest predator, scavenger, and (in native range) important frugivore/seed disperser.

Regulates populations of invertebrates and small vertebrates via predation Scavenges carrion, contributing to nutrient recycling Disperses seeds of fleshy-fruited plants (endozoochory) when fruit consumption is high In invaded systems, can negatively impact native wildlife through predation on eggs, juveniles, and small vertebrates

Diet Details

Main Prey:
Insects Other arthropods Gastropods Earthworms and other soft-bodied invertebrates Amphibians small reptiles Bird eggs and nestlings Small mammals Carrion +3
Other Foods:
Fleshy fruits Berries and drupes Figs Guava Palm fruits Flowers and soft plant material

Human Interaction

Domestication Status

Wild

Argentine black and white tegu (Salvator merianae) is wild, not domesticated. People in South America long harvest it for meat, fat/oil, and leather. Recently it is bred worldwide and kept as an exotic pet; some become tame but not true domestication. Released pets made it invasive in parts of the U.S., prompting trapping, reports, and rules.

Danger Level

Moderate
  • Bite injury: strong jaws and sharp, recurved teeth can cause deep lacerations; risk increases with stressed, untrained, or cornered animals and during feeding.
  • Claw scratches and tail-whip impacts: large adults can inflict painful scratches/bruising.
  • Zoonotic disease risk common to reptiles (e.g., Salmonella): transmission via fecal contamination/handling; higher risk for children, elderly, and immunocompromised people.
  • Invasive-population impacts that indirectly affect humans: predation on eggs/young of native wildlife (including ground-nesting birds and reptiles) can drive human-wildlife conflict and management actions; tegus may raid poultry eggs or small livestock feed in peri-urban/rural areas.
  • Allergic/irritant exposures: contact dermatitis is uncommon but possible from contaminated substrates/cleaners used in husbandry.

As a Pet

Suitable as Pet

Legality: Laws vary. In the U.S. many states allow keeping Argentine black and white tegu (Salvator merianae), but some ban or restrict them. Florida lists it as Prohibited, requiring permits, secure cages, microchips, and limits.

Care Level: Experienced

Purchase Cost: $150 - $800
Lifetime Cost: $8,000 - $25,000

Economic Value

Uses:
Exotic pet trade (captive breeding, retail, supplies) Commercial harvest/use in native range (food and leather) Invasive-species management and control services (trapping, removal, research) Education/outreach (zoos, nature centers, responsible ownership programs) Scientific research model (physiology/thermal biology/reproduction/ecology)
Products:
  • Live animals (captive-bred juveniles/adults)
  • Custom large enclosures/caging and environmental control equipment (heat/UVB/thermostats/substrates)
  • Processed skins/leather (tegu leather)
  • Meat/eggs/fat/oil used locally in parts of the native range (where practiced and legally sourced)
  • Field control outputs (trapping/removal programs; monitoring data)

Relationships

Related Species 6

Red tegu Salvator rufescens Shared Genus
Dusen's tegu Salvator duseni Shared Genus
Lorenz Müller's tegu Salvator lorenzmuelleri Shared Genus
Gold tegu Tupinambis teguixin Shared Family
Four-lined tegu Tupinambis quadrilineatus Shared Family
Giant ameiva Ameiva ameiva Shared Family

The Argentine black and white tegu is native to South America and is a popular pet due to its docile nature and intelligence. The tegu can grow up to five feet in length and have a lifespan of 10 to 12 years. It is an omnivorous animal, and its diet consists of small mammals, birds, lizards, frogs, and invertebrates. In the wild, these reptiles are found in tropical forests but can adapt to various habitats. Argentine black and white tegus are social creatures, and in captivity, they should be kept in pairs or groups. They require a spacious enclosure with plenty of hiding places, as well as access to UVB lighting and a basking spot. These reptiles are semi-aquatic, so their section should also include a water bowl or pond.

5 Incredible Argentine Black and White Tegu Facts

  • The Argentine black and white tegu is the largest species of tegu lizard, reaching up to five feet in length in some cases.
  • These lizards are native to South America and can be found in countries like Argentina, Brazil, Paraguay, and Uruguay.
  • Argentine black and white tegus make great pets due to their docile nature and dog-like qualities, such as loyalty and companionship.
  • Argentine black and white tegus are known for their impressive intelligence as well.
  • These lizards are also great swimmers and have been known to travel long distances across rivers in search of food or new territory.

Scientific Name

The Argentine black and white tegu is a giant lizard native to South America. The scientific name for this animal is known as Salvator merianae, while it gets its common name from its black and white coloration. Its scientific name is named in honor of German naturalist Maria Sibylla Merian.

Appearance

Argentine Black and White Tegu

Healthy Argentine black and white tegus weigh between 15 and 20 pounds.

This incredible reptile is native to Argentina, Brazil, Paraguay, and Uruguay. It is one of the most significant members of the tegu family, reaching lengths of up to five feet. On average, the females are much smaller than the males of this species, with females growing up to just three feet long. A healthy Argentine black and white tegu weighs around 15 to 20 pounds.

The Argentine black and white tegu is easily recognizable by its striking and mottled black-and-white beaded skin. However, the Argentine black and white tegu typically have bright green heads when they are first born. But the bright emerald color fades and becomes black as the young tegu sheds.

Evolution

The Argentine black and white tegu has undergone some evolutionary changes. One change is that it has become more adapted to living in captivity. This is likely because more people are keeping them as pets. Another difference is that the average size of the lizard has increased slightly over time. This could be due to better care and nutrition in captivity, or it could be a result of natural selection. Overall, the Argentine black and white tegu is a fascinating creature that has undergone some exciting changes over time.

Argentine Black and White Tegu Behavior

One of the coolest things about the Argentine black and white tegu is its behavior. When threatened, this lizard will hiss loudly and try to intimidate its attacker by inflating its body and opening its mouth wide. If that doesn’t work, the tegu will bite. And if all else fails, it will run away as fast as it can. An awesome adaptation of this reptile is that it can drop its tail on the floor as a distraction if attacked, giving it a moment to save itself by running away. And due to its sheer size, this lizard can also use its tail to strike its opponent.

The Argentine black and white tegu is a very intelligent reptile that can make an excellent pet for those willing to take the time and effort to care for them properly. They are active and curious animals that require much space to roam, so they might be better suited for life in a larger enclosure.

Argentine Black and White Tegu Habitat

The Argentine black and white tegu is found in Argentina, Brazil, Paraguay, and Uruguay. Their habitats include subtropical and tropical moist lowland forests, subtropical and tropical dry shrubland, subtropical and tropical seasonally wet or flooded lowland grassland, rivers, swamps, freshwater marshes, pastureland, rural gardens, and urban areas. They also inhabit human-modified habitats such as agriculture (e.g., soybean fields) and livestock pastures. And since many consider this reptile a pet, Argentine black and white tegus have been found to live in human-made enclosures too.

Argentine Black and White Tegu Diet

These lizards are omnivorous, which means they eat both plants and animals. The Argentine black and white tegu’s diet consists of insects, small mammals, reptiles, birds, and eggs in the wild. They will also eat fruits and vegetables.

When in captivity, it is essential to provide a varied diet that includes all the food groups mentioned above. An excellent way to do this is by feeding them a mixture of commercially prepared reptile food and live prey items. It is also necessary to offer them a variety of fruits and vegetables so that they can get the nutrients they need.

What Eats the Argentine Black and White Tegu?

Large birds, jaguars, snakes, and other larger animals will eat a tegu.

What Does the Black and White Tegu Eat?

The black and white tegu can eat various foods, including insects, fruits, and vegetables.

Argentine Black and White Tegu Predators and Threats

One of the main predators of the Argentine black and white tegu is the jaguar. They are mighty hunters that use their sharp claws and teeth to kill their prey. Jaguars typically live in forested areas but have been known to venture into other habitats in search of food.

Another major predator of the Argentine black and white tegu is the boa constrictor. They kill their prey by wrapping their bodies around them and squeezing tightly until they suffocate. Boa constrictors typically live in tropical rainforests but have inhabited other habitats such as deserts or mountains.

In addition to predators, there are also some potential threats that Argentine black and white tegus may become victims of. One of these threats is disease. Some diseases that Argentine black and white tegus can contract include salmonella and cryptosporidiosis. These diseases can be transmitted through contact with contaminated food, water, or another infected animal. Therefore, if in captivity, owners need to provide their Argentine black and white tegus with clean food and water sources and regular vet check-ups to prevent disease transmission.

Another potential threat is injury from being stepped on or crushed. This can be avoided if an owner provides their pet with a suitable, safe enclosure with enough space to move around freely. Owners must ensure that their Argentine black and white tegu has plenty of room to exercise and explore without being at risk for injury.

Argentine Black and White Tegu Reproduction

Argentine black and white tegus use chemical cues to search for mates in the area. Female tegus more often take the lead in finding a potential mate by following these chemical scent trails. These reptiles mate in the spring right after hibernation when their hormones peak.

The Argentine black and white tegus are oviparous, which means they lay eggs. After mating, the female tegu will lay a clutch of 10 to 30 eggs in a nest she has dug herself, but some females may lay even more eggs, depending on their health. The eggs will then incubate for between 40 to 75 days before hatching. The female tegu potentially produces dozens of offspring over her lifetime.

Argentine Black and White Tegu Babies

As hatchings, the young tegus are born fully formed and independent in the beginning of spring. Unlike their adult counterparts, young tegus are born with an emerald green head with black markings. After shedding a few times over several months, this green color eventually fades and turns black. 

When they first hatch, Argentine black and white tegu babies weigh only 0.35 ounces, but they quickly grow and can weigh up to 20 pounds in just 4 or 5 years, which is when they stop growing.

These young Argentine black and white tegus typically reach sexual maturity within two or three years when they are around 3 to 3.5 pounds. Then the cycle continues again.

Argentine Black and White Tegu Lifespan

Argentine black and white tegus typically live between 10 and 12 years in captivity, though some individuals have been known to live up to 15 years. Their lifespan is likely shorter in the wild due to predation and other factors. Several things can affect an Argentine black and white tegu’s lifespan, both positively and negatively. Proper diet and nutrition are essential for maintaining a healthy tegu and providing a clean and safe enclosure. Avoiding stressors such as handling too much or too little will also help them to live a long life. Some threats to the Argentine black and white tegu include, but are not limited to:

  1. Predators
  2. Disease
  3. Habitat loss
  4. Humans

Argentine Black and White Tegu Population

According to a study conducted in 2013, the estimated global population of Argentine black and white tegus is between 1,000 and 10,000. Most of these tegus are found in Argentina, where they are native, but they have also been introduced to other countries in South America, such as Brazil and Uruguay. Tegus are famous pets due to their docile nature and intelligence, which means that many of these reptiles are kept in captivity.

It is difficult to estimate how many tegus are kept as pets because there is no central registry. However, it is thought that the number of captive tegus far exceeds the number of wild ones. The popularity of tegus as pets has contributed to their decline in the wild. Tegus are often captured from the wild to be sold as pets, which puts pressure on wild populations. In addition, habitat loss and fragmentation due to human activity are significant threats to these animals.

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Sources

  1. Animal Spot / Accessed February 15, 2023
  2. Florida Fish and Wildlife Conservation Commission / Accessed February 15, 2023
Lev Baker

About the Author

Lev Baker

Lev is a writer at AZ Animals who primarily covers topics on animals, geography, and plants. He has been writing for more than 4 years and loves researching topics and learning new things. His three biggest loves in the world are music, travel, and animals. He has his diving license and loves sea creatures. His favorite animal in the world is the manta ray.
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Argentine Black and White Tegu FAQs (Frequently Asked Questions)

The Argentine black and white tegu is omnivorous, as it eats both vegetation and meat.