Reptile & Amphibian Forums

Ok, flame me, come over and smack me upside the head, I don't care. I have been searching for an answer and can't seem to find it. My question is "What is the difference between a monitor and a tegu". Sam if you answer this use language a poor, old, hick from Alabama can understand.lol

Scott
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Do not meddle in the affairs of dragons, for you are crunchy and taste good with ketchup.

Scott,

Monitors and tegus are members of different families of lizards. Tegus are the largest species in the family Teiidae, which includes whiptails and many other small species that range throughout the New World. Monitors comprise the family Varanidae, which is presently restricted to the Old World (though monitors once occurred in North America as well). In many ways, tegus fill the same ecological niches in South America that are occupied by medium-sized monitors in Africa, Asia and Australasia -- they are actively-hunting predators, mostly terrestrial or semiaquatic, that use both visual and olfactory cues to find prey.

Teiids and varanids are not particularly closely related to one another; instead, they are an example of convergent evolution, where similar body forms and behaviors result from adaptation to similar lifestyles.

That help?

I was just curious because my tegu has alot of the same traits that my monitors have.

Scot
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Do not meddle in the affairs of dragons, for you are crunchy and taste good with ketchup.

In terms of their physiology, tegus are pretty typical lizards, while monitors are a bit more like mammals. Like most lizards, tegus are unable to breathe while running, because of the way their chest flexes as their forelegs move. Turns out it doesn't much matter, because tegus, like most lizards, rely on glucose stored in their muscles and run anaerobically. Their leg and back muscles are pale ('white meat', like chicken breast), and like chickens flying, they tire out pretty quickly.

Monitors can breathe while running, and use aerobic metabolic pathways almost all of the time. Their muscles are red (from myoglobin, which stores oxygen), same as the leg muscles of chickens ('dark meat", eh). Like chickens running, monitors can go a very long way before they tire out.

The difference then is between "burst" speed and "endurance" speed, and monitors would win any race. This hasn't a whole lot of relevance to keeping either tegus or monitors in captivity, except to note that cooling a monitor down does it a lot more damage than does cooling a tegu. Tegus can shut down metabolically and pop back once warmed up again, while for many monitors this would pose a major physiological problem. Oddly, the main place that tegus have aerobic (red) muscles is in their jaws, and many people can attest to the point that a tegu can bite and hold on until Sunday if it chooses, whereas monitors are more likely to let go in a half hour or so.

This is also why tegus are better eating than are monitors, unless you like that gamey flavor that comes from myoglobin.

Hi Sam and others,

Some years ago, ~1993-94, a friend of mine was managing the (now) defunct Long Island Serpentarium in its earliest stages of development. His standards are high, as compared to today with law suits and alike abound there. Anyways, in December, a pair of V.s. cumingi escaped from their heated enclosure and went cruising the rafters aloft. A hole in the roof from weight of ice on said roof caused the wintery ice-cold to come into the building one night, causing the V.s. cumingi to freeze - SOLID - when they were found, they were hard as a rock, literally, frozen solid! Nobody was sure how long they were frozen solid?

Well, they were slowly thawed out in warm, warmer, alot warmer water and observed closely...they came around, slowly! They were not dead, but alive! The revived completely, eating and doing vara-things normal to them, but one side-eefect to this Robert Scott scenario was they were apparently 'insane' following their forced hibernation, i.e. the higher brain was dead but lower brain was intact...does this imply that varanids came from northern latitudes as many theorize? I don't know?? It is a interesting observation never-the-less....I wonder if Tegu's could endure this as well? Probably so as per their physiology.

cheers,
mbayless

Varanids are unique in they are the only lizards with a snake type tougue(long and forked). The books say, they are the only lizards with a forked tougue, but tegus, some skinks and gilas have a short fat forked tougue.

Having a snakelike tougue, is very very special and allows them to sense a whole different world then other lizards. As well has having keen eyesight.

Varanids have other nice adaptions as well, the development of the hyloid process, as allowed them to consume a larger varity of sizes of prey. Both the above brings varanids closer to the modern world of snakes.

Just something to think about, the development of the snakelike tougue, can allow the monitors to see(sense) in the dark, like snakes. hmmmmmmmmm FR