Amphisbaenians are perhaps the least known of the reptiles, even more obscure than the tuatara. They are also known as "worm lizards", and constitute a suborder of their own within the Order Squamata (the lizards and snakes), but in appearance and structure are actually not closely related to the lizards. Amphisbaenians are normally two feet long at most and resemble giant earthworms, with the obvious difference that as vertebrates they have a bone structure. In this aspect they resemble the caecilians, their counterparts in the Class Amphibia. It is true that there are legless lizards, but the amphisbaenians also differ in having a reduced right lung, a much greater degree of bone in the skull as opposed to cartilage, which is more prevalent in lizard skulls, and scales which are arranged in rings known as annuli around the body (hence the earthworm appearance). As with many burrowing animals, the eyes have become reduced to vestigial status.
There are 130 species of amphisbaenians, divided among three families: the Bipedidae, Trogonophidae and Amphisbaenidae. A fourth family, the Rhineuridae, comprising one species, Rhineura, is now generally considered part of the Amphisbaenidae. The three Bipedidae species have a pair of reasonably well-developed hands on very short legs near the head, but otherwise amphisbaenians have no external limbs visible. The name amphisbaenian, roughly translated, means "going both ways", a reference to the fact that some of these creatures can in fact move backwards and also to the difficulty in visually ascertaining at first glance which way round the creature is pointing.
Amphisbaenians are rarely seen in the pet trade, even among exotics: in fact I have never seen one offered for sale, either in a shop or at a fair. Come to think of it, I don't even recall seeing one at London Zoo or any other such institute. Part of this is probably due to their low display value: after all, a creature that spends all its time hidden in a substrate (literally burrowing, as opposed to the mere digging in of some lizards) is hardly likely to make a good talking point. Amphisbaenians are also not exactly common in nature: confined to tropical and sub-tropical parts of America and Africa, plus the south of Spain and Portugal, their lifestyle makes them hard to find, much less catch in numbers for the pet trade. But as in the case of caecilians, one might consider this a pity in some ways. The very lack of information we have on these strange reptiles will hopefully be a spur to some individuals to make further studies.
According to Mattison, care of captive amphisbaenians is actually fairly easy. The main requirement is a substrate several inches deep of sand, sandy soil or leaf-litter, depending on the creature's area of origin. A heat pad is placed under one end of the tank to allow limited thermoregulation. In some cases a flat rock with a moist area underneath is also provided. Food will be in the form of normal invertebrates - crickets, mealworms, waxworms and earthworms - dropped into the tank. These can be allowed to run about as the amphisbaenian will consume them from underneath the surface. For this reason, Mattison also warns that no other reptiles of any sort should be kept in a tank with an amphisbaenian, as the larger amphisbaenians are certainly carnivorous and will consume dead rodents or canned pet food. Rundquist recommends pinkie or furry mice offered every other week and once or twice a month supplemented with a liquid multivitamin at a dosage of 0.1 cc vitamins per 440 g body weight of captive. Lean beef or horsemeat is also apparently acceptable. He also warns against feeding frozen fish to amphisbaenians, a tendency he has noticed.
Information on individual species is very thin. In an effort to redress the balance, and to make the amphisbaenians more accessible to herpetophiles and the general public, we offer what data we can on the basic families and genera of this suborder. However, this will take some time to complete. Apart from using the inestimable EMBL database to check the species names and origins, all other data has come from field guides to certain areas (so far, only Africa and Europe).
For more information on the various amphisbaenian species, please click on one of the family links below.
|Trogonophidae||Short-Headed Worm Lizards|
|Bipedidae||Two-Legged Worm Lizards|
The Heidelberg zoology site has some generic data on the order, its families and species. This is rather dry but useful taxonomic classification material, especially as it gives the place of origin for each species.
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