The Argentine black and white tegu (''Salvator merianae''), also known as the Argentine giant tegu, the black and white tegu, the huge tegu,
[ is a ]species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of lizard
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...
in the family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Teiidae
Teiidae is a family of autarchoglossan 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 Gymnopthalmidae, and both families ...
. The species is the largest of the "tegu
Tegu is a common name of a number of species of lizards that belong to the families Teiidae and Gymnophthalmidae. Tegus are native to Central and South America. They occupy a variety of habitats and are known for their large size and predator ...
lizards". It is an omnivorous
An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...
species which inhabits the tropical rain forest
Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equatori ...
s, savanna
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...
s and semi-desert
A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...
s of eastern and central South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...
.
Tegus are sometimes kept as pets by humans. They are notable for their unusually high intelligence and can also be housebroken
''HouseBroken'' is an American animated sitcom created by Jennifer Crittenden, Clea DuVall, and Gabrielle Allan that premiered on Fox Broadcasting Company, Fox on May 31, 2021. In August 2021, the series was renewed for a second season which prem ...
. Like other reptiles, tegus go into brumation
Dormancy is a period in an organism's life cycle when growth, development, and (in animals) physical activity are temporarily stopped. This minimizes metabolic activity and therefore helps an organism to conserve energy. Dormancy tends to be clos ...
in autumn when the temperature drops. They exhibit a high level of activity during their wakeful period of the year. They are the only known reptiles to be partly endothermic.
Tegus fill 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 resources and competitors (for ...
s similar to those of monitor lizard
Monitor lizards are lizards in the genus ''Varanus,'' the only extant genus in the family Varanidae. They are native to Africa, Asia, and Oceania, and one species is also found in the Americas as an invasive species. About 80 species are recogn ...
s, but are only distantly related to them; the 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 com ...
.
Etymology
The specific name, ''merianae'', is in honor of German-born naturalist Maria Sibylla Merian
Maria Sibylla Merian (2 April 164713 January 1717) was a German naturalist and scientific illustrator. She was one of the earliest European naturalists to observe insects directly. Merian was a descendant of the Frankfurt branch of the Swiss Mer ...
, a naturalist and artist who studied insects, plants, and reptiles from the 17th to the 18th centuries.
Description
As a hatchling, ''Salvator merianae'' has an emerald green color from the tip of its snout to midway down its neck, with black markings. The emerald green becomes black several months after shedding. As a young tegu, the tail is banded yellow and black; as it ages, the solid yellow bands nearest to the body change to areas of weak speckling. Fewer solid bands indicates an older animal. A tegu can drop a section of its tail as a distraction if attacked. The tail is also used as a weapon to swipe at an aggressor; even a half-hearted swipe can leave a bruise.
Tegus are capable of running at high speeds and can run bipedally
Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning 'two feet' (from Latin ''bis'' 'double' a ...
for short distances. They often use this method in territorial defense, with the mouth open and front legs held wide to look more threatening.
Adult males are much larger than the females and can reach in length at maturity. They may continue to grow to lengths of .
The females are much smaller, but may grow up to in length from nose to tail. They have beaded skin and stripes running down their bodies. Adult females can reach a weight of .
The skull is heavily built with a large facial process of the maxilla, a single premaxilla, paired nasals, a single frontal bone and two parietal bones separated by the sagittal suture. Biomechanical analyses suggest the posterior processes of the parietal might be important for dealing with torsional loads due to posterior biting on one side. In the large adults, the posterior teeth are larger and more rounded than the anterior teeth.
Sex
When a tegu reaches the age of 8 months, the beginning of their juvenile age, their sex can easily be determined visually; their vent at the base of the tail will bulge when it is a male and lie flat when it is a female. Breeders generally inform the buyer on the sex of the animal before the purchase. In adults, the main difference is in the jowls; adult males have substantially developed jowls (a result of hypertrophic lateral pterygoideus muscles), while females' jawlines are more streamlined.
Ecology
Distribution and habitat
As the name would suggest, this tegu is native to Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
, but also to Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
, Paraguay
Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...
and Uruguay
Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...
.
''Salvator merianae'' (once known as ''Tupinambis merianae'') aka the Argentine Black and White Tegu is a large reptile native to South America. There are significant populations of Argentine Black and White Tegus in the southern United States and the Brazilian coast. They are a consistently problematic invasive species in Florida counties, most likely as a result of escaped or released species from the early 2000s pet trade. Previous studies have found that the differing weather and climate patterns far outside of their natural habitat range do not prevent adult Argentine Black and White Tegus from surviving in diverse areas across the United States, furthering concerns about their invasive status. In the wild, tegus habitat both forested and open plain environments, widening their potential invasive range.
Tegus have also been found in scrub and wet habitats such as flooded savannas, canals, ponds, and streams. They largely seem indiscriminate of habitat type as long as they have the ability to burrow.
Diet
Tegus are omnivorous. Juvenile tegus in the wild have been observed to eat a wide range of invertebrates including insects, annelids, crustaceans,[ in ] spiders and snails. They also eat fruits and seeds. As they grow, they become more predatory and the protein content of their diet rises. They may seek out eggs from other reptiles' and from birds' nests and will eat small birds and other vertebrates such as fish, anurans, other lizards, snakes and small mammals (such as rodents). In adulthood, tegus continue to eat insects and wild fruits and it is assumed that such components include desirable or essential nutrients. They also can hunts on more large prey, for example on armadillo
Armadillos (meaning "little armored ones" in Spanish) are New World placental mammals in the order Cingulata. The Chlamyphoridae and Dasypodidae are the only surviving families in the order, which is part of the superorder Xenarthra, along wi ...
s
In captivity, tegus commonly are fed high protein diets that include raw or cooked flesh such as ground turkey, canned and dry dog food, commercial crocodile diet, chicken, eggs, insects and small rodents. The inclusion of fruit in the diet is recommended. Though some captive tegus do not readily eat fruit, others enjoy bananas, grapes, mangoes and papayas. However, there is evidence that, as in most husbandry of carnivores, it is good practice to cook most of the egg in the diet, so as to denature the protein avidin
Avidin is a tetrameric biotin-binding protein produced in the oviducts of birds, reptiles and amphibians and deposited in the whites of their eggs. Dimeric members of the avidin family are also found in some bacteria. In chicken egg white, avidin ...
that occurs in the albumen
Egg white is the clear liquid (also called the albumen or the glair/glaire) contained within an egg. In chickens it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms arou ...
. Raw avidin immobilises biotin, so excessive feeding of raw eggs may cause fatal biotin deficiency
Biotin deficiency is a nutritional disorder which can become serious, even fatal, if allowed to progress untreated. It can occur in people of any age, ancestry, or of either sex. Biotin is part of the B vitamin family. Biotin deficiency rarely oc ...
.
As adults, they have blunted teeth and exaggerated lateral pterygoid muscles which allow them to be generalist feeders. In captivity, they have been observed eating various feeder insects like mealworms, superworms, earthworms, silkworm
The domestic silk moth (''Bombyx mori''), is an insect from the moth family Bombycidae. It is the closest relative of ''Bombyx mandarina'', the wild silk moth. The silkworm is the larva or caterpillar of a silk moth. It is an economically imp ...
s, crickets
Crickets are orthopteran insects which are related to bush crickets, and, more distantly, to grasshoppers. In older literature, such as Imms,Imms AD, rev. Richards OW & Davies RG (1970) ''A General Textbook of Entomology'' 9th Ed. Methuen 8 ...
and cockroaches, as well as vertebrate prey like mice
A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
, rats, fish, turkey (offered in a ground form), rabbit, quail and chicks. Crustaceans such as crayfish
Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...
are also readily consumed. Like all lizards, blue tegus need a properly balanced diet; incomplete prey items such as insects or ground meat require dusting with a mineral/multi-vitamin supplement. Vitamin deficiencies can lead to trouble shedding skin
''Shedding Skin'' is the third album by British singer, songwriter and musician Ghostpoet. The album was nominated for the 2015 Mercury Music Prize
The Mercury Prize, formerly called the Mercury Music Prize, is an annual music prize awarded ...
, lethargy and weight loss; a calcium deficiency can lead to metabolic bone disease
Metabolic bone disease is an abnormality of bones caused by a broad spectrum of disorders. Most commonly these disorders are caused by deficiencies of minerals such as calcium, phosphorus, magnesium or vitamin D leading to dramatic clinical disord ...
, which can be fatal.
Tegus are notorious egg predators which makes them a concerning rising predator of sea turtles, alligators, and crocodiles as their invasive populations spread across the United States.
Tegus will eat anything from plants to hatchlings, but their diet varies by season. Small vertebrate prey is more common in the spring while plant life and invertebrates are more commonly consumed in the summer.
Mortality
Predators of tegus include cougar
The cougar (''Puma concolor'') is a large Felidae, cat native to the Americas. Its Species distribution, range spans from the Canadian Yukon to the southern Andes in South America and is the most widespread of any large wild terrestrial mamm ...
s, jaguar
The jaguar (''Panthera onca'') is a large cat species and the only living member of the genus '' Panthera'' native to the Americas. With a body length of up to and a weight of up to , it is the largest cat species in the Americas and the th ...
s, otter
Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the Mustelidae family, which also includes wea ...
s, snake
Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...
s and birds of prey
Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predators ...
. A known predator of the Argentine black and white tegu is the lesser grison
The lesser grison (''Galictis cuja'') is a species of mustelid from South America.
Description
Lesser grisons have a long, slender body, short legs, and a bushy tail. They have a long neck and a small head with a flattened forehead and rounded ea ...
(''Galictis cuja''), a mustelid related to weasels. ''Salmonella enterica
''Salmonella enterica'' (formerly ''Salmonella choleraesuis'') is a rod-headed, flagellate, facultative anaerobic, Gram-negative bacterium and a species of the genus ''Salmonella''. A number of its serovars are serious human pathogens.
Epidemi ...
'' was found in fecal samples from almost all ''S. merianae'' at a captive breeding field station at State University of Santa Cruz
The State University of Santa Cruz ( pt, Universidade Estadual de Santa Cruz, UESC) is a public institution of higher education in Brazil, based in the city of Ilhéus, Bahia. Until the 1990s, it was the only university in the city.
As of 2020, the ...
, Ilhéus
Ilhéus () is a major city located in the southern coastal region of Bahia, Brazil, 211 km south of Salvador, Brazil, Salvador, the state's capital. The city was founded in 1534 as Vila de São Jorge dos Ilhéus and is known as one of the mos ...
, Bahia
Bahia ( , , ; meaning "bay") is one of the 26 Federative units of Brazil, states of Brazil, located in the Northeast Region, Brazil, Northeast Region of the country. It is the fourth-largest Brazilian state by population (after São Paulo (sta ...
state, Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
illustrating the prevalence of salmonella infection in tegu lizards.
Life cycle
Argentine black and white tegu lizards are typically born at the beginning of spring. When they hatch they are about ten grams and grow up to eight kilograms within four or five years, experiencing a nearly eight-hundred-fold increase in body size. During this time their diet changes from insects to small vertebrates, eggs, carrion, and fruits. They are reproductively mature by their third year (when they are around 1.5 kilograms), and cease their growth by around their fourth year with the highest growth rate being their first and second years of life. Tegu lizards also experience a seasonal circadian life cycle that begins within their first year, being very active during hotter months and in a hibernative state in the colder months. However, regardless of the season the Argentine tegu does not experience any significant fluctuations in metabolism or body mass, which means their sensitivity to temperature underlying their metabolic rate does not change body mass. This differs from other endotherms and further explains the tegu's alternating endothermic and ectothermic behavior.
Brain vesicles (constructed from two neural tube constrictions) that make up the anterior forebrain, midbrain, and posterior hindbrain are developed and distinguishable from day three of embryonic development. On day four, visceral arches (consisting of mesenchymal tissue condensation and separated by grooves) form and are fully grown and fused by day nine. Day four also marks the development of limbs as small swellings. Its hindlimb development (developing claws faster than the forelimb) is more similar to crocodile or turtle embryonic development than other lizards. This alludes to the hindlimbs having greater functionality in tegu adults. Pigmentation is the last morphological structure to form and occurs late in development after other distinguishing characteristics have already been formed (such as scales). Pigmentation is observed from day thirty-nine first on the dorsal portion of the head and body. It later extends down to the proximal and distal portions of the limbs by day forty-five and extends down to the flanks by day forty-eight. As development advances, the pattern begins to show lateral stretch marks by day fifty-one. Pigmentation of the ventral portion of the body occurs between days fifty-seven and sixty, characterized by individualized spot patterns. Paired genital tubercles manifest in both sexes (called hemipenes in males). Reptile embryo development involves separate processes of differentiation and embryo growth. Differentiation is determined by external morphological features and is documented early. As the embryo approaches hatching, development stages are categorized into periods rather than ages (characterized by parameters of development speed).
Behavior
Aggression
Aggression is a vital facet to animal behavior as it provides advantages to survival when resources are limited. For the Argentine tegu, the physical performance of their aggressive behavior (i.e. biting) tends to be hindered by their large size. Regardless of sex, tegus with higher bite force are more aggressive to potential threats. Those with a higher bite force also exhibit less escape responses and tend to be slower, displaying a trade off of fight or flight abilities, but also have the advantage of minimizing risk of energy by reducing the threshold for engagement in an aggressive encounter. This fight or flight trade off is more commonly observed in mammals rather than reptiles, and may be present in tegus because of an increase in head mass (correlated to stronger biting behavior) that makes it difficult to maneuver quickly. In their home territory, Argentine tegus are generally less aggressive (less likely to display arching behavior) and are less likely to attempt escape regardless of size or bite force.
Reproduction
Squamate reptiles like snakes and lizards tend to rely on chemical cues to search for potential mates in their environments. The Argentine black and white tegu exhibits similar behavior, such as a marked "pausing and turning" as they trail in the spring. In particular, female tegus exhibit stronger trailing behavior than males, following scent trails more intensely and expressing a more sensitive response to mating-specific chemical odors. They also exhibit more decisive behavior, demonstrating a common vertebrate trend of female reproduction being the defining factor in influencing population size. Knowledge of this behavior is currently being explored as a strategic avenue to inhibit the current rise of the tegu as an invasive species. Prioritizing the removal of female tegus from the environment can potentially be a more effective way to curb these invasive populations. Tegus are a burrowing species in both their native and invasive habitats, especially during the winter. They mate during the spring after hibernating when their mating hormones are at their peak. During the spring, male Argentine tegus exhibit scent-marking behaviors such as delineating territory with gland scents.
Blue tegus, like other tegus, may breed up to twice a year. They only lay between 18 and 25 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 a ...
s in a clutch
A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). ...
, sometimes more dependent upon animal size and husbandry as well as the individual health of the gravid female.
During maternal seasons, female Argentine black and white tegus build nests out of dry grass, small branches, and leaves in order to maintain optimal temperature and humidity levels. Egg incubation lasts for an average of sixty-four days, with a range of forty to seventy-five days depending on incubation temperature and other extenuating factors.
Physiology
Invasive advantage
Physiologically, tegus possess traits that correlate well with their extreme success as an invasive species. Notably, they mature early, reproduce annually, have large clutch sizes, and a relatively long life span compared to other competing species. Out of the Teiidae family, tegus tend to grow to the largest body sizes (around five kilograms). Tegus are also omnivorous and consume everything from fruits, invertebrates, small vertebrates, eggs, and carrion. Their large dietary breadth also contributes to their high survival rate outside of their native habitat. Tegus are active on a seasonal schedule. They avoid dangerously cold or dry climates by hibernating underground. Additionally, they are capable of utilizing endothermy to elevate their body temperatures in response to their environment.
Endothermic behavior
Tegus in their native environment spend most of the colder months hibernating in their burrows without feeding but emerge in the spring for their mating season. While hibernating, their metabolism generates heat that maintains their temperature a few degrees above the burrow temperature, marking them as partial endotherms. This self-reliant endothermic behavior continues into the reproductive season
Seasonal breeders are animal species that successfully mate only during certain times of the year. These times of year allow for the optimization of survival of young due to factors such as ambient temperature, food and water availability, and cha ...
. However, Argentine tegus only display this behavior for part of the year and behave as ectotherms for the rest (sunbathing, temperature reliant on environment). This endothermic behavior is also not a sex-biased evolutionary adaptation for egg production as both males and females indiscriminately exhibit this behavior.
The Argentine tegu experiences significant shifts in metabolism and body temperature by season. They are highly active throughout the day during warmer months (such as participating in reproductive endothermy during the spring) and experience drastic metabolic suppression during the winter.
''Salvator merianae'' has recently been shown to be one of the few partially warm-blooded lizards, having a temperature up to higher than the ambient temperature at nighttime; however, unlike true endotherms such as mammals and birds, these lizards only display temperature control during their reproductive season (September to December), so are said to possess seasonal reproductive endothermy. Because convergent evolution is one of the strongest lines of evidence for the adaptive significance of a trait, the discovery of reproductive endothermy in this lizard not only complements the long known reproductive endothermy observed in some species of python
Python may refer to:
Snakes
* Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia
** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia
* Python (mythology), a mythical serpent
Computing
* Python (pro ...
s, but also supports the hypothesis that the initial selective benefit for endothermy in birds and mammals was reproductive.
Locomotion
The Argentine black and white tegu is used to study the evolutionary history of shoulder joint locomotive muscles. Because of its weight and heavy girth, it has unique modifications to its skeletal gait that help map the evolutionary history of the non-mammalian musculoskeletal structure.
Interactions with humans and livestock
As household pets
When black and white tegu are kept as pets, they can be fed proteins, fruits, and vegetables. Some examples of proteins that they can be fed are live bugs such as meal and horn worms, dubia roaches, and crickets. Other sources of protein include canned insects, scrambled or hard boiled eggs, snails, ducklings, chicks, boiled organ meats, shrimp, mice, or rats that are either alive or have been previously frozen and then thawed. The black and white tegu may be fed fruits and vegetables as well. For example, they can be fed berries such as strawberries, raspberries, and blueberries. They can also be fed bananas, apples, kiwis, pears, pumpkins, melons, peas, squash, apricots, mangos, figs, papaya, cantaloupe, and grapes.
Blue tegu
The blue tegu is a variant known for its light blue coloration, which is most intense and vivid in the adult males. Even immature animals can be easily distinguished from other mostly black and white tegus by the "singe mark" on their nose. They are among the more suitable tegus for pets and can be easily tamed but, in the wild, will either try to run away or react aggressively if provoked. There is much controversy about the correct scientific classification of this animal. Large-scale taxon sampling of the teiids has not led to any strong resolutions based on morphological and genetic data; the majority of data about the blue tegu comes from hobbyists. Some believe it is a mutation of the Argentine black and white tegu, while others, including the original importer, believe it is sufficiently different to have its own classification. The first blue tegu to be exported from South America was in a wholesale shipment of tegus from Colombia.
The coloring of a blue tegu can range from a simple black and white color to albino
Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes. Individuals with the condition are referred to as albino.
Varied use and interpretation of the term ...
to powder blue to even "platinum
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver".
Platinu ...
", which is basically a high white color morph
In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the s ...
. The colouration does not tend to appear until the animal reaches sexual maturity around the age of 18 months or it reaches or more in size. Just like the Argentine black and white tegu, the blue tegu has a very quick growth rate, almost reaching 75% of its full length in 1 year. Their adult length can vary from in adult females to sometimes even longer than in adult males. Unlike other lizards, these are very heavily built animals, ranging from or more when fully grown. Size is relative to genetics as well as husbandry and diet.
Captive husbandry
To accommodate their size, a lone adult should be housed in nothing smaller than a × × size cage, with the largest floor size possible. A pair of adults need double that size. They must have a lot of floor space. About six inches of substrate should be used to allow for burrowing, as well as a substrate that holds humidity well. Most owners use cypress mulch mixed with coconut fiber, as it retains humidity extremely well and is commercially available. Use only organic substrates, as anything with pesticides or additives, much like what you would commonly find at a hardware store, will cause many health issues with your tegu, including death. A good UVA
UVA most often refers to:
* Ultraviolet A, a type of ultraviolet radiation
* University of Virginia, a public research university in Charlottesville, Virginia, United States
Uva or UVA may also refer to:
Places
* Uva, Missouri, an unincorpora ...
and UVB bulb is imperative to keeping a tegu in good health. They need UVB to produce Vitamin D in their bodies, as well as metabolizing calcium. If they are not allowed exposure to UVB on a daily basis, they can experience severe pain and/or deformities from diseases such as metabolic bone disease. Along with UVB, a blue tegu also needs a temperature gradient. This means that one side of the cage must be cooler, while the other is much warmer and provides a basking spot. This is so they can regulate their body temperature by going to whatever temperature works for them at the moment. Ambient temperatures on the cooler side should be around and the warmer side should be about . They also need the surface of their basking spot to meet specific temperature requirements. For juveniles and younger tegus, they need it around , though, as they get older, it can go up to . For healthy shedding, a humidity of 60-80% is preferred.
Like most lizards, fresh water should be provided daily. Like other tegu species, you should make sure your Argentine black and white tegu has enough water to soak in if they wish. Some tegu species are also known to enjoy swimming and, since they grow to about long or more, a medium-sized to large cat litter box can be used as an appropriately sized water dish. Never allow the water level to be above shoulder height for a tegu, as many tegus commonly drown when left without supervision.
Legality
On May 28, 2021 the South Carolina Department of Natural Resources
The South Carolina Department of Natural Resources (DNR) is a South Carolina state agency charged with regulating hunting, fishing, boating, duck stamp orders, and the conservation efforts of the state government.
It is directed by seven-member ...
banned importation and breeding, and requires registration of black and white tegus already in South Carolina.
As food
''S. merianae'' - like a lot of animals used for bushmeat
Bushmeat is meat from wildlife species that are hunted for human consumption, most often referring to the meat of game in Africa. Bushmeat represents
a primary source of animal protein and a cash-earning commodity for inhabitants of humid tropi ...
- is a common food source for humans in its native range and could be an economically and dietarily beneficial meat source if used more widely.
Leather trade
The Argentine black and white tegu has long been hunted for their skins to supply the international leather trade. They are one of the most exploited reptile species in the world, but trade is legal in most South American countries. It is not an endangered species and overharvesting has not as of yet been monitored.
Invasive species
Argentine black and white tegus have also escaped from the pet trade
Wildlife trade refers to the of products that are derived from non-domesticated animals or plants usually extracted from their natural environment or raised under controlled conditions. It can involve the trade of living or dead individuals, ti ...
in Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
and are now an invasive species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
in Florida, Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the Caucasus region of Eurasia
* Georgia (U.S. state), a state in the Southeast United States
Georgia may also refer to:
Places
Historical states and entities
* Related to the ...
and South Carolina
)''Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no)
, anthem = " Carolina";" South Carolina On My Mind"
, Former = Province of South Carolina
, seat = Columbia
, LargestCity = Charleston
, LargestMetro = ...
. The first sighting of ''S. merianae'' in Berkeley County, South Carolina was on September 10, 2020. Eight total sightings in South Carolina have been recorded as of September 10, 2020.
The Argentine Black and White Tegu has been a particular threat to native wildlife like birds and reptiles that build nests or burrows on the ground. Notably, they exhibit a particular type of both predatory and competitive behavior known as intraguild predation. Argentine tegus will pursue and kill but not eat other native reptiles, which worsens their invasive effect on wildlife. Efforts such as placing traps or localized hunting have been largely unsuccessful in eradicating their egregious effect on non-native environments.
Because of their invasive threat to native and imperiled species, population containment initiatives have been a priority in the past ten years, leading to the extraction of nearly 3,300 tegus from Miami-Dade County alone. Unfortunately such efforts have been difficult. Historically, tegus have survived brutalizing harvests amid the leather trade, marking them a remarkably resilient species.
Taxonomy
In 1839, this species of tegu was originally described as ''Salvator merianae''. However, beginning in 1845 and continuing for 154 years, it was confused with ''Tupinambis teguixin'' and was considered a synonym of that species. In 1995, it was again given species status as ''Tupinambis merianae'' because subsequent studies had shown that the gold tegu
The gold tegu, also known as the golden tegu, common tegu, black tegu, Colombian black and white tegu and tiger lizard (in Trinidad), is a species of tegu. Its old scientific name (synonym) was ''Tupinambis nigropunctatus'', but it has since ren ...
(''Tupinambis teguixin'') was distinct from it. In 2012, the Argentine black and white tegu was reassigned to the resurrected genus ''Salvator'' as ''Salvator merianae''.
''S. merianae'' is called the "Argentine black and white tegu" to distinguish it from the "Colombian black and white tegu", which is another name for the gold tegu. Unscrupulous or incompetent pet dealers sometimes pass off gold tegus as Argentine black and white tegus.
''S. merianae'' and ''T. teguixin'' can be distinguished by skin texture and scale count:
*''S. merianae'' has two loreal scale
The lore (adj. loreal) is the region between the eyes and nostrils of birds, reptiles, and amphibians.
Ornithology
In ornithology, the lore is the region between the eye and bill on the side of a bird's head. This region is sometimes featherles ...
s between the eye and the nostril.
*''T. teguixin'' has only one loreal scale between the eye and the nostril.
In the ecotone
An ecotone is a transition area between two biological communities, where two communities meet and integrate. It may be narrow or wide, and it may be local (the zone between a field and forest) or regional (the transition between forest and gras ...
between the arid Chaco and the Espinal of central Argentina, they are known to naturally hybridise with the red tegu (''Salvator rufescens'') with a stable hybrid zone
A hybrid zone exists where the ranges of two interbreeding species or diverged intraspecific lineages meet and cross-fertilize. Hybrid zones can form ''in situ'' due to the evolution of a new lineage but generally they result from secondary contact ...
.
See also
*Gold tegu
The gold tegu, also known as the golden tegu, common tegu, black tegu, Colombian black and white tegu and tiger lizard (in Trinidad), is a species of tegu. Its old scientific name (synonym) was ''Tupinambis nigropunctatus'', but it has since ren ...
*Tegu
Tegu is a common name of a number of species of lizards that belong to the families Teiidae and Gymnophthalmidae. Tegus are native to Central and South America. They occupy a variety of habitats and are known for their large size and predator ...
*''Teius
''Teius'' is a genus of lizard that belongs to the family Teiidae.
Classification
Listed alphabetically.Teius teyou
''Teius teyou'', the four-toed tegu,''Teius t ...
''
References
External links
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*
Care for Argentine Black and White Tegus
- PetsWithScales.com
Further reading
*
{{Taxonbar, from1=Q24354290, from2=Q2254602
Salvator (lizard)
Reptiles described in 1839
Reptiles of Argentina
Reptiles of Bolivia
Reptiles of Brazil
Reptiles of Paraguay
Taxa named by André Marie Constant Duméril
Taxa named by Gabriel Bibron
Reptiles as pets