Tegu is a

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...

of a number of

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

lizards Lizard is the common name used for all squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The ...

that belong to the families

Teiidae Teiidae is a family of lacertoidean lizards native to the Americas. Members of this family are generally known as whiptails or racerunners; however, tegus also belong to this family. Teiidae is sister to the Gymnophthalmidae, Gymnopthalmidae, and ...

and

Gymnophthalmidae Gymnophthalmidae is a family of lizards with at least 250 species, sometimes known commonly as spectacled lizards or microteiids. They are called "spectacled" because of their transparent lower eyelids, which allow them to still see with closed ...

. Tegus are native to Central and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. They occupy a variety of habitats and are known for their large size and predatory habits.

Description

Tegus are, usually, black mixed with other colors and patterns; some have yellow, reddish or white bands along their backs, others have lines going down their bodies with unique markings on their sides. Their body shape is aerodynamic with long tails and strong legs. Most tegus grow to about a metre long, but the black and white tegu (''S. merianae'') can grow to about 1.3 metres. Although, in appearance, tegus resemble the Varanidae (monitors), they are not closely related to them. Their initial similarities are an example of

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last comm ...

, when unrelated or distantly-related species develop physical or behavioral similarities based on

ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of Resource (biology), resources an ...

, adaptations or environment. Tegus use their tongues and vomeronasal organ to find chemical cues associated with their prey and other lizards. A vomeronasal organ is an organ of chemoreception located in the nasal chamber.

Habitat

Tegus naturally occur in

rainforest Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

semiarid thorn forests,

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...

s, fields and

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

s. They have also adapted to open areas created by agriculture, parks and construction zones. They spend much of their time in

burrow file:Chipmunk-burrow (exits).jpg, An eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of Animal lo ...

Diet

As omnivores, tegus feed on various foods including

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

s, small

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...

s and

carrion Carrion (), also known as a carcass, is the decaying flesh of dead animals. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...

. Tegus living near humans may raid chicken coops for eggs and baby chicks, or scavenge leftover food such as crackers,

cheese Cheese is a type of dairy product produced in a range of flavors, textures, and forms by coagulation of the milk protein casein. It comprises proteins and fat from milk (usually the milk of cows, buffalo, goats or sheep). During prod ...

and chips.

Behaviour

When confronted, a wild tegu initially stops moving with its head held up high, then attempts to flee. It may turn aggressive if cornered, biting and attacking with its tail. In contrast, captive-raised tegus can be docile, intelligent and social with their carers. Tegus are popular in the international pet trade as owner's often compare them to dogs due to their loving, casual nature. In the coolest areas of their range, such as northern

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

, tegus hibernate from June to September.

Endothermy

During the reproductive season, Argentine black and white tegus can raise their body temperature by up to 10 °C above the ambient temperature (seasonal reproductive

endotherm An endotherm (from Greek ἔνδον ''endon'' "within" and θέρμη ''thermē'' "heat") is an organism that maintains its body at a metabolically favorable temperature, largely by the use of heat released by its internal bodily functions inst ...

y). This may be advantageous when coming out of hibernation, regrowing

gonad A gonad, sex gland, or reproductive gland is a Heterocrine gland, mixed gland and sex organ that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gon ...

s, producing gametes (

gametogenesis Gametogenesis is a biological process by which diploid or haploid precursor cells undergo cell division and differentiation to form mature haploid gametes. Depending on the biological life cycle of the organism, gametogenesis occurs by meiotic d ...

), mating, and (for females) producing eggs and incubating them.

Importance

Tegus are traditionally hunted for their meat, fat, and hides. Argentine black and white tegus are widely and successfully bred and kept as

pets A pet, or companion animal, is an animal kept primarily for a person's company or entertainment rather than as a working animal, livestock, or a laboratory animal. Popular pets are often considered to have attractive/ cute appearances, int ...

, with red tegus being slightly less common in the hobby but still present. Additionally, '' Dracaena guianensis'', the northern caiman lizard, is growing in popularity among breeders and hobbyists. Some species have become invasive in the U.S. state of

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

and southern parts of

Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...

Genera

"Tegu" generally refers to species of lizard in the genus '' Tupinambis'', which belongs to the family

. Not all lizards known as tegus belong to the same

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

. The word "tegu" may refer to species in any of the following genera: * '' Callopistes'': "dwarf tegus" (2 species) * '' Crocodilurus'': the "crocodile tegu" (1 species) * '' Dicrodon'': "desert tegus" (3 species) * '' Dracaena'': "caiman tegus", also known as "caiman lizards" (2 species) * '' Euspondylus'': "sun tegus" (11 species) * '' Proctoporus'': "sun tegus" (17 species) * '' Salvator'' (3 species, including the

Argentine black and white tegu The Argentine black and white tegu (''Salvator merianae''), also Common name, commonly known as the Argentine giant tegu, the black and white tegu, the blue tegu, and the huge tegu, is a species of lizards in the Family (biology), family Teiidae ...

) * '' Teius'' (3 species, including the "four-toed tegu") * '' Tupinambis'' (8 species)

References

{{Animal common name Teiidae