A colorful medley of stunning shells appeared below: apple murexes, glistening cowries the size of grapefruits – and deadly cone snails.  “Watch out!” I mumbled in alarm through my snorkel to our sons, who swam nearby.
   Cone snails (family Conidae) are carnivores that primarily eat fish and marine worms, but they can be killers of men.  We’d been warned about them by the local Fijians.  A week earlier, they’d told us, a diver oblivious to the cone snail’s threat had to be airlifted 2,000 miles to Australia; he arrived in the nick of time and survived.   It boggled our minds: These gorgeous shells look like ice-cream cones!  And I’d been worried about sharks?
    I went for a swim, and armed with a wooden salad spoon, I turned over a golden cone in the sand.  Seeing no one home, I tucked it into a peanut butter jar that dangled from my bikini.  To other cones, we all gave a wide berth.

     Cone snails are ruthless hunters: During the day, they bury themselves in sand; at night, they lumber around the sea floor on the prowl.  They use a scarlet proboscis to attract fish and lure them into their snare.  When a fish is detected, the snail shoots a venom-packed barbed harpoon into its victim.  Once immobilized, the fish is drawn into the snail’s mouth.  Spines, scales, and the disposable harpoon are regurgitated after digestion.
      With their striking patterns and elegant shapes, cone snails appear harmless, but many collectors, entranced by the shells, have suffered stings.  Some of these have proved to be fatal; the sting of one kind of cone snail carries enough venom to kill 700 people.  No antivenom exists to combat these toxins.  People stung by cone snails die from paralyzed diaphragms, rendering them unable to breathe.
     On the upside, derivatives of the cone-snail venom show great promise as painkillers; the U.S. Food and Drug Administration has already approved one derivative as an alternative to morphine.
Whenever I show our collection of cone-snail shells to friends, Adam and Warren writhe and wail in mock agony, just to tease me. 

     “Cute,” I say.