Venomous Snail of Southern Seas

August 05, 2015


Photographer: David K. Lynch 
Summary AuthorDavid K. Lynch
The Textile Cone (Conus textile) is found in the warm, shallow waters of the Indo-Pacific oceans. This one was found in the lagoon of Kwajalein Atoll in the Marshall Islands. Its shell has a distinctive and attractive pattern making it a favorite among shell collectors. But beware! Accidentally stepping on a cone snail while wading could result in a nasty wound that could prove fatal.

All cone snails are predators and hunt using a harpoon-like stinger (actually a modified tooth) that snaps out and injects their prey. The conotoxin is a fast-acting neurotoxin and quickly paralyzes the victim. Textile Cone’s close cousin Geography Cone (Conus geographus) is even more dangerous. Its venom is composed of hundreds of amino acids for which there is no antivenom. The lethal dose to humans is in the neighborhood 0.01-0.03 mg/kg, making it the most deadly poison in the world. Thus only about 1 mg could kill a 200 lb (90 kg) human. Cones can also stun prey by releasing an insulin-like substance into the gills of fish resulting in hypoglycemic shock.