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Lizards
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 I purchased my sheltopusik, Xhevat (left), in February of 2000; when fully stretched out, he is about three feet long. Although a sheltopusik superficially looks like a snake, a closer look at the head (right) and body reveals a much more lizard-like morphology. |
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The sheltopusik, also known
as the
European legless lizard, certainly doesn't look like a lizard
at
first glance; it's long, thin,
and lacks any functional limbs. Accordingly, it is commonly
mistaken
for a snake. (It's name, in fact, means "snake lizard.")
Not
having limbs
doesn't make something a snake, however; snakes have many
other
special morphological features not present in animals like lizards.
For instance, snakes have a very light, mobile skull that
allows
them to swallow food items much larger than their head; most lizards
have a much less mobile skull designed for biting and chewing instead
of just swallowing. Similarly, a lizard like the sheltopusik
has
an external opening for the ear, and eyelids that can be raised and
lowered (like most animals); snakes lack any external vestiges of an
ear
and have specially
modified eyelids known as spectacles that permanently cover
they
eye. Movement in limbless lizards and
snakes is also very different; a sheltopusik moves in a somewhat stiff,
mechanical manner and is not capable of forming the tight coils so
typical of snakes. Like the plated lizards (and unlike
snakes),
sheltopusiks have a fold (or groove) along the side of the body near
the belly that expands and contracts with the animal's breathing.
The fold extends from just behind the head
to the base of the tail, a point about halfway along the total length
of
the animal, marking the site of the cloaca;
everything in front of the cloaca is the body and the rest is tail.
In most snakes the body is proportionately much longer than
in
sheltopusiks, with the cloaca being located closer to the tip of the
tail. The reason sheltopusiks don't have any limbs is the same reason many lizards (such as other anguids, pygopodids, and anniellids) have become limbless; they have adopted a fossorial lifestyle, living in the underbrush, burrowing through soft substrates, and eating invertebrates and small vertebrates they encounter in these habitats. For these animals, limbs mostly just get in the way. And since it takes valuable resources to grow and maintain limbs, it's much better to lose them through evolutionary time than to have them and not use them. The sheltopusik (like some snakes) still has very tiny remnants of the hind limbs, visible as small nubbins on either side of the cloaca. Sheltopusiks are native to far eastern Europe and western Eurasia and aren't commonly encountered in the North American pet trade. However, they are very easy to care for and have a reputation as living for a long time (more than 50 years in captivity), so they're a good investment as far as a lizard is concerned. I keep my sheltopusik in a 30 gallon aquarium (36" long x 16" high x 12" deep; see photo below) with a snake-proof lid. (Mine pushes on the aquarium top periodically, so a secure top is essential.) Although I originally used a natural (soil) substrate for the tank, I have subsequently found that Bed-A-Beast (made from ground coconut husks) is preferable; it's much cleaner, is great for burrowing, and holds moisture well. Additionally, the lizard's droppings can be easily seen against the uniform color of the substrate, permitting spot-cleaning and only periodic replacement. I keep a medium-sized water bowl in one corner of the tank and usually let the water overflow whenever I fill it; the bedding around the bowl absorbs the water, giving the sheltopusik a dry end and a moist end of the tank to choose from. Since the sheltopusik is not a basking lizard, I don't use any special UV bulb; illumination is supplied by a regular fluorescent strip light and heat is provided by a clip lamp with an incandescent bulb. My sheltopusik generally eats just three things: nitecrawlers, canned cat food (any type), and (dead) mice.  The sheltopusik isn't a huge fan of being handled - though I haven't made much of an attempt to habituate him - but his protests are more show than anything else. When picked up, he'll spin around and around (in an attempt to get free) and lunge and hiss like he's going to bite, but I've never had him actually bite me (or anyone else). If you hold the lizard loosely in the middle of its body, the lizard will spin but not be able to get a grip and will eventually calm down. A friend of mine in the Chicago Herpetological Society has been bitten by a sheltopusik, however, and says they can give a good bite; so it never hurts to be too careful. Still, I think unless food is involved, the odds of being bitten are low. Sheltopusiks are closely related to a group of lizards living in the United States known as glass lizards. These limbless lizards are so named because, when grabbed by the tail, they not only can drop their tail (like many lizards), their dropped tail can also break into several smaller pieces - like shattered glass. An interesting thing I noticed while watching Raiders of the Lost Ark is that - in the scene where Indy is lowered into the tomb filled with snakes - most of the "snakes" are actually sheltopusiks. (I did some searching on the web, and could find only one article that mentions this fact.) Why the producers of the film decided to use so many limbless lizards instead of snakes, I have no idea. Maybe many of the actors actually did have a fear of snakes. But as far as I know, it represents one of the only instances of sheltopusiks having their 15 minutes of fame. |
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This
page was last updated on December 12, 2006.
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