Micrurus fulviusEastern Coral Snake, Harlequin Coralsnake

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Geographic Range

There are five subspecies. M. f. fulvius occurs in southeast N. Carolina south through Florida and west to Louisiana. The other four range from western Louisiana southwest through southern Texas to eastern & central Mexico (Barbour & Earnst 1989).

Habitat

M. fluvius spends most of the time buried in the soil, in forest areas among decaying logs, leaves, and rocks. It seems to prefer dry, open or brushy areas, occasionally in marshy areas (Conant & Collins 1991).

Physical Description

Banded with red, white, or yellow and black on which the red and yellow bands lie beside each other, and the snout is black. Size ranges from two-three feet (Barket 1964). The body scales are smooth and occur in 15 rows throughout; the anal plate is divided.

Confusing species: several subspecies of Lampropeltis triangulum and the species Cemophora coccinea also have red, yellow and black bands crossing their bodies, but their red and yellow bands are separated by black bands and their snouts are red instead of black (Barbour & Ernst 1989).

Reproduction

M. fulvius breeds from late spring early summer and late summer to early fall. Eggs are laid during May to July. There are approximately 37 days between copulation and ovipostion. Clutches of 5-7 eggs will be laid and the young will hatch approximately 60 days later (Barket 1964, Stebbins 1966).

Females mature at a snout-vent length of about 55cm in 21-27 months. Males mature sexually usually around 45cm or longer reached in 11-21 months.

Ovary weights increase from March through April, and decline slightly in May and then more rapidly in June. There is complete regression with spermatogonia and Sertoli cells in May through August, with a peak in June (Barbour & Ernst 1989).

Lifespan/Longevity

Behavior

M. fluvius is largely a diurnal snake. It possesses a bimodel activity pattern with more activity from March to May and, again, from August to November (Barbour & Ernst 1989).

M. fluvius is solitary except when breeding. It can be aggressive towards its own species but it is otherwise mild mannered and does not attack humans. Snake bite death usually occurs from carelessness by the human and poor medical treatment.

For defense, M. fluvius uses color and disruptive patterning: a predator does not know which end is the head or tail, thereby confusing the predator. It will swing its tail in an attempt to mimic a head, or it will rattle its tail and emit a popping sound with its vent lining (Bayou Bob 1997, Belize Zoo 1999).

Food Habits

M. fulvius' diet consists mostly of snakes, including its own species. It also eats lizards, birds, frogs, fish, and insects. It uses venom to kill its victims (Stebbins 1966).

Economic Importance for Humans: Positive

Their neurotoxic venom is one of the venoms used in antiserum for snake bites. Venom is also being researched like many other venomous snakes. Research is being done for cancer, AIDS, and other disabilitating diseases. Without these animals for research we may lose many key cures.

Economic Importance for Humans: Negative

Although it is not likely to be bitten by a wild coral snake, unless it is harassed, the venom is extremely toxic and can cause death.

Conservation Status

Other Comments

Their family is represented around the world but only two Micruroides occur in the U.S. (Barbour & Ernst 1989). Ten percent of non-treated bites are fatal. Being a relative of the cobra, the bite fools you, small amount of pain and swelling at first, and small punctures. Powerful nerve toxin symptoms are delayed and can be fatal if not treated. Called the twenty minute snake because people believed you would die within that time. Since the venom is neurotoxic, more likely to occur in 24 hours. The coral snake is the only venomous snake in North America that lays eggs (Barket 1964, Stebbins 1966).

Contributors

Shannon Chapman (author), Michigan State University, James Harding (editor), Michigan State University.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

native range

the area in which the animal is naturally found, the region in which it is endemic.

References

Barket, W. 1964. Familiar Reptiles and Amphibians of America. Harper and Row Publishers.

Bayou, B. 1997. "Bayou Bob's Reptiles" (On-line). Accessed September 27, 1999 at http://www.wf.net/~snake/coral.htm.

Belize Zoo, 1999. Accessed October 1, 1999 at http://www.belizezoo.org/zoo/zoo/herps/cor/cor1.html.

Conant, R., J. Collins. 1991. Reptiles and Amphibians Eastern/Central North America. New York: Hougton Mifflin Company.

Stebbins, R. 1966. A Field Guide of Reptiles and Amphibians. Cambridge: The Riverside Press.