Newspaper article The Tuscaloosa News

ECOVIEWS: Sometimes Poison Is a Matter of Life or Death

Newspaper article The Tuscaloosa News

ECOVIEWS: Sometimes Poison Is a Matter of Life or Death

Article excerpt

The arsenals used by plants and animals throughout the world in waging chemical warfare are fascinating. Finding commonalities and dissimilarities between various groups reveals how diverse the natural world can be. The primary function of injection by many venomous animals is to acquire their prey, although toxic chemicals are also used defensively.

Examples of venomous injection methods include the nematocysts of a jellyfish, the tail stinger of a stingray and the stinging hairs of some caterpillars. Even some plants, such as the common stinging nettle, are technically venomous as tiny hairs on the leaves and stem can penetrate the skin and release histamines when someone brushes against them. My grandchildren are no longer a threat to stinging nettles because all have learned firsthand the perils of tramping through a patch of this well-armed plant.

A few of the world's mammals qualify as venomous, the best known being the male duckbill platypus of Australia. A sharp spur on each hind foot is connected to a venom gland and a duct that transfers the toxin to the barbed structure. The short-tailed shrews of the eastern United States have toxic saliva that enters the body of prey, or would-be predators, when the shrew bites it.

Poisonous organisms differ from venomous ones in that the noxious chemical is not injected, but can be injurious if eaten, touched or even inhaled (such as smoke from burning poison ivy). Some toxins can enter the bloodstream through a cut or the lining of mucus membranes. Poison ivy produces an oily substance that causes dermatitis in some people upon contact with leaves, stems or roots. Death angel mushrooms and poison hemlock produce chemicals that are harmful if eaten. Common garden toads secrete distasteful toxins from skin glands.

No venomous birds have yet been discovered and, presumably, none exist. But the pitohui birds in New Guinea have poisonous skin and feathers. The chemical composition of the poison is similar to that in the skin of poison dart frogs of Colombia, South America. These deadly little frogs secrete a toxic chemical, a type of alkaloid that makes them unpalatable to other animals. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.