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WINTER 2012
Bites and Stings
North America’s venomous denizens
B Y B R I A N H A R P E R
A
s divers, we dutifully learn to treat the bites and
stings of a variety of animals from around the
world, including jellyfish, lionfish, fire coral, sea
snakes and cone snails. But we may not be as
familiar with the venomous creatures we’re more likely to
encounter close to home.
SNAKES
In North America there are two general types of venomous
snake: pit vipers and elapids. Pit vipers, also called crotaline
snakes, are the continent’s most common venomous
snakes. The name pit viper comes from special heat-
sensing organs the snakes have. These organs, deep pits
near the snakes’ nostrils, allow the snakes to “see” the heat
radiating from their prey. Rattlesnakes, copperheads and
cottonmouths are the three major types of North American
pit vipers.
There are more than 30 species of rattlesnake, and
all are endemic to the Americas. They are common
across the continents, ranging as far north as British
Columbia and Alberta. Of the dozen or so fatalities due
to snakebite that occur in North America each year,
rattlesnakes are responsible for about 80 percent of
them. Cottonmouths, also called water moccasins, are
found throughout the southeastern U.S., where they
live near swamps, streams and ponds. They are known
for their threat displays; males of the species tend to
be territorial and display a gaping behavior, opening
their mouths toward intruders to expose light-colored
tissues, giving rise to the common name “cottonmouth.”
Copperheads are not particularly aggressive but will
strike when provoked. Unlike rattlesnakes, which often
coil to strike, or cottonmouths, which tend toward
territorial displays, copperheads frequently lie still when
encountered. This behavior likely evolved because of
their excellent camouflage.
Coral snakes are the only North American
representatives of the elapidae family, which includes the
RESEARCH, EDUCATION & MEDICINE
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