Toxic treasure: poisons and venoms from deadly animals could become tomorrow's miracle drugs. And few places on Earth harbor so many deadly animals as Australia's Great Barrier Reef.(Cover Story)

Publication: Natural History

Publication Date: 01-OCT-05

Bookmark this article Print this article Link to this article Email this article Digg It! Add to del.icio.us RSS

COPYRIGHT 2005 Natural History Magazine, Inc.

[Australia] has more things that will kill you than anywhere else.... This is a country where even the fluffiest of caterpillars can lay you out with a toxic nip, where seashells will not just sting you but actually sometimes gofer you.... It's a tough place.

--Bill Bryson, In a Sunburned Country

Raised, as you probably were, on film or video footage of drowsy koalas hugging eucalyptus trees, or kangaroos bouncing happily around the outback, you might wonder just what country Bryson is talking about. But consider the unassuming cone shell--just the kind of malicious mollusk that will "actually sometimes go for you."

The cone shell is a marine snail that lives in tropical regions worldwide, including the waters around northeastern Australia's Great Barrier Reef. The snail aggressively reaches out to sting prey or would-be predators, injecting toxins that are among the most powerful in the animal kingdom. Even a diminutive member of the genus Conus can carry enough venom to kill a dozen people; a single careless encounter can bring death in less than thirty minutes. What's more, the radula, a harpoonlike stinger that delivers the venom, can strike with enough speed and force to pierce a diver's wetsuit. There is almost no pain associated with a cone-shell sting, because the venom contains a strong analgesic. That's the good news. The bad news is that the toxin is a nerve agent for which there is no known antidote.

Why would anyone intentionally seek out a creature whose venom packs such a wallop? Answering that question goes a long way toward explaining why Australians, whose continent is well known for its gold and opals, have begun studying their richly varied animal populations with renewed interest. Latter-day prospectors on the continent are searching for biologically active chemicals throughout Australia's biting, stinging, venomous fauna. Those chemicals and their derivatives could turn out to be both a pharmaceutical bonanza and the foundation of a multimillion-dollar industry.

In Brisbane, for instance, laboratory workers at a six-year-old biotechnology company called Xenome Ltd have the unenviable task of "milking" cone shells. The job is not an easy one. Because the snail can bend its proboscis to sting from virtually any angle, there is no safe way to hold a live cone shell. To get the venom, the technicians dangle a small fish from forceps for the snail to sting. The snail's venom kills the fish, but it can then be safely extracted from the fish's tissue. In spite of that roundabout--and costly--procedure, Xenome's...

Read the full article for free courtesy of your local library.