Stingray,

Saturday, February 17, 2007

Q: The unfortunate death of Australian Steve Irwin has been repeatedly reported as resulting from a poisonous stingray barb. Isn't the dangerous bony barb on the stingray covered in slimy bacteria, like other saltwater creatures, rather than having a poison-delivery system like a rattlesnake?
A: Poisonous and venomous are not the same thing. Poison is ingested or absorbed (through the skin, etc.); venom is injected.
The stingray is venomous, not poisonous, says Tom Schmid, president and chief executive officer of the Texas State Aquarium.
"There are venomous glands located in grooves on the ventral side of the (stingray's) spine. The venom is made up of a high molecular weight protein and causes a tremendous amount of pain. . . . Around the entire spine is a thick mucus sheath that contains very high levels of bacteria," Schmid explains.
Death by stingray is rare. The stingray's barb (venom, bacteria and all) does not appear to be what caused Irwin's death. The barb punctured Irwin's chest cavity and heart.
When swimming, remember that stingrays like to rest on the ocean floor, partially clad in sand. To decrease your chances of stepping on a stingray, shuffle through the sand rather than lifting your feet. That is the advice of "Stingray 101," a feature on the Animal Planet Web site (animal.discovery.com). Stung? Because venom is a protein, heat counters its effect, Schmid says.