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Wormlizards: Amphisbaenidae

White-bellied Wormlizard (amphisbaena Alba): Species Account

Physical characteristics: Among the largest members of the family, the white-bellied wormlizard can grow to 33.4 inches (85 centimeters) long with a body that can reach up to 2 inches (25 centimeters) wide. Adults can, however, be much smaller, growing to only half that size. Of their total length, only 6 percent is tail. Like other wormlizards, their scales form rings around the body and give the animal an earthworm-like appearance. The scales on their back are small and square. They have a rounded head with one large tooth and six smaller ones in the front of the upper jaw.

White-bellied wormlizards almost always stay in underground tunnels, buried under dead leaves, or inside the nests of leaf-cutter ants. (Illustration by John Megahan. Reproduced by permission.)

Geographic range: The white-bellied wormlizard lives in Panama, which is in far southern Central America, in the West Indies, and in South America east of the Andes Mountains.

Habitat: This burrowing animal almost always stays in its underground tunnels, buried under dead leaves, or inside the nests of leaf-cutter ants.

Diet: With its strong jaws, the white-bellied wormlizard can eat animals as large as mice and rats in a scientist's laboratory. In the wild, however, they are known only to eat smaller animals, such as ants, termites, crickets, and other insects, as well as spiders and other invertebrates (in-VER-teh-brehts), which are animals without backbones.

Behavior and reproduction: Unlike other wormlizards that drop the tail when they feel threatened, this species cannot. Instead, it curls up its body so the head and tail are next to one another, and then raises its head and opens wide its mouth while lifting up and swaying its tail. This behavior makes the wormlizard almost look as if it has two heads, and, in fact, some people call it a "two-headed snake." Females lay eight to 16 eggs at a time, probably once a year during the dry season.

White-bellied wormlizards and people: White-bellied wormlizards and people rarely run across one another.

Conservation status: This species is not considered endangered or threatened. ∎



Gans, C. Biomechanics: An Approach to Vertebrate Biology. Philadelphia: J. B. Lippincott Company, 1974.

Halliday, Tim, and Kraig Adler, eds. The Encyclopedia of Reptiles and Amphibians. New York: Facts on File, 1986.

Mattison, Chris. Lizards of the World. New York: Facts on File, 1989.

Schwenk, K. "Feeding in Lepidosaurs." In Feeding: Form, Function, and Evolution in Tetrapod Vertebrates. San Diego: Academic Press, 2000.

Vanzolini, P. E. Evolution, Adaptation and Distribution of the Amphisbaenid Lizards (Sauria: Amphisbaenidae). Ph.D. diss. Harvard University, 1951.

Web sites:

"Amphisbaenidae." Innvista. http://www.innvista.com/science/zoology/reptiles/amphisba.htm (accessed on December 9, 2004).

"Family Amphisbaenidae." Animal Diversity Web. University of Michigan Museum of Zoology. http://animaldiversity.ummz.umich.edu/site/accounts/classification/Amphisbaenidae.html (accessed on December 1, 2004).

"The Keeping and Maintenance of Amphisbaenians." Cyberlizard (UK). http://www.nafcon.dircon.co.uk/amphisb1.html (accessed on December 1, 2004).

"The ReptiPage: Amphisbaenia." The ReptiPage. http://reptilis.net/amphisbaenia/overview.htmlhtml (accessed on December 9, 2004).

Additional topics

Animal Life ResourceDinosaurs, Snakes, and Other ReptilesWormlizards: Amphisbaenidae - Physical Characteristics, Geographic Range, Diet, Behavior And Reproduction, White-bellied Wormlizard (amphisbaena Alba): Species Account - HABITAT, WORMLIZARDS AND PEOPLE, CONSERVATION STATUS