Blindsnakes

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Blindsnakes

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These tiny, primitive burrowers live underground and forage for ants, termites, soft-bodied insects, and insect larvae. The eyes of most blindsnakes are degenerate; they are covered by scales and do not function. However, the eyes do have light-sensitive cells (rods), so these snakes may not be completely blind. The head is large and the mouth, like a sharks, is below and behind the snout, which is blunt or hooked. There is a tiny spine under the snakes stubby tail that anchors the animal while burrowing. The body is covered with smooth, tough, shiny scales, which cover even the belly, making it difficult for the snake to slither on solid surfaces. The body is cylindrical, either thin or thick. Blindsnakes are commonly black or brown, although some species completely lack any pigment.

Blindsnakes are classified in three familiesthe Typhlopidae (wormsnakes), the Leptotyphlopidae (threadsnakes), and the Anolmalepidae. The Typhlopidae and Leptotyphlopidae are so similar that most herpetologists include both in the Scolecophidia. Both families have a remnant pelvic girdle, one lung, and one oviduct. Threadsnakes have large teeth in the lower jaw and none in the upper jaw, while worm-snakes have teeth only on the upper. The fifteen species of threadlike Anomalepidae of tropical South America are also included in the Scolecophidia, but this family has teeth on both jaws and no vestigial pelvic girdle.

The eighty species of threadsnakes are found in tropical South America, Africa and the southern United States, and range in length from 6-16 inchds (15-41 cm). Some species release foul-smelling excretions to ward off ravaging predators such as army ants. The Texas threadsnake incubates her eggs by muscular shivering to raise its body temperature, a strategy found in only one or two species of python.

The 200 species of wormsnakes occur in tropical and temperate South America, Africa, Madagascar, southern Europe, Asia, and Australia. Wormsnakes range in length from 4.5 inches (11.5 cm) to about 3 feet (91.5 cm). The Brahminy wormsnake is parthenogenic, the only species of snake to reproduce without mating, and every specimen found so far is female. This tiny species lives among plant roots and is transported by unsuspecting humans carrying potted plants from place to place. A single Brahminy worm-snake can populate an entirely new region.

Blindsnakes are harmless to humans, except for a species from India that is reputed to crawl into the ears of people sleeping on the ground.

See also Reptiles.

Resources

BOOKS

Bellairs, Angus. The Life of Reptiles. Vols. I and II. New York: Universe Books, 1970.

Cogger, Harold G., David Kirshner, and Richard Zweifel. Encyclopedia of Reptiles and Amphibians. 2nd ed. San Diego, CA: Academic Press, 1998.

Mattison, Christopher. Snakes of the World. New York/Oxford: Facts on File Publications, 1986.

Zug, George R., Laurie J. Vitt, and Janalee P. Caldwell. Herpetology: An Introductory Biology of Amphibians and Reptiles. 2nd ed. New York: Academic Press, 2001.

OTHER

Singapore Zoo Docents. Blindsnakes (Infraorder Scolecophidia) <http://www.szgdocent.org/resource/rr/c-blind.htm> (accessed November 6, 2006).

Marie L. Thompson