Those that eat worms have the weakest venom – our local cones eat marine worms – but those that eat fish and mollusks can produce highly venomous toxins. Cones feed on worms, mollusks, or small fish. There are about 700 species of cone snails, marine gastropod molluscs/mollusks.Īnnesley showed us a short video clip of a highly venomous live cone snail and the speed at which they can attack and paralyze their prey and then devour them. Before I get too deep into this, I want to say the cone snails in our local waters are not the highly venomous ones, but live ones can sting you and cause discomfort – handle with care. How many islanders have collected cone shells on our island beaches? How many of you know that live cone shells/cone snails are venomous and some of their species can exude a toxic poisonous venom that can kill humans? Well, I really had no idea until Friday morning. Annesley has an astounding resume with degrees and educational appointments in the areas of pathology, clinical chemistry in pathology, biochemistry, and drug analysis and toxicology, and this all has, to an extent, a connection to his topic of the day. He is an active professor emeritus at the University of Michigan and deputy editor of the journal “Clinical Chemistry.” Annesley has always had an interest in oceanography and spent summers in California, where his uncle dropped him off at the costal tide pools on his way to work and then picked him up on his way home. Tom Annesley and quite familiar to many people on the island, since he is the president of the Sanibel-Captiva Shell Club and an important member of the volunteer educational team at the Bailey-Mathews National Shell Museum.Īnnesley does public lectures at the museum, leads beach walks, and docents at the live shell tank at the museum. The topic was “Cone snails, tennis rackets, and pain medications – A Mollusk’s Story.” Oh, my. This past week, the speaker’s name was not familiar nor after reading the speaker’s topic was I aware of what we were going to learn about that morning. Tom Annesley, president of the Sanibel-Captiva Shell Club, was the guest speaker at the Sanibel-Captiva Rotary Club's recent meeting.Įvery Friday before leaving my home for our weekly Sanibel-Captiva Rotary Club meeting, I check out who is going to be our speaker that morning. And check a previous article in the Curator’s Corner explaining the formation of cone snail teeth here.Dr. Read more the work being done at Schulz’s lab here. When contact with the prey is made and pressure overcomes the forces of the latch, the tooth is released, much like a bullet shooting through a gun barrel, delivering venom through the prey’s skin. A protuberance on the tooth base holds the tooth in place, held by a latch inside the proboscis (see attached images). Cat Cones (and probably other fish-hunting species) have a unique mechanism that allows for the high-pressure build-up of venom inside the proboscis. Fish-hunting cone snails use fast-acting toxins (the venom) and a super-fast venom delivery system. The entire strike happens in less than 100 microseconds (a microsecond is one millionth of a second), with accelerations exceeding 280,000 m/s2 (the metric system unit for acceleration is meters per second square for comparison, a car acceleration is about 3 to 4 m/s2.) Radular teeth of cone snails resemble harpoons, with the hollow shaft acting as a conduit to deliver venom to the prey (see enclosed scanning image of the tooth of Conus catus).
Schulz from the Occidental College in Los Angeles and his collaborators have shown that the strike by the radular tooth of the fish-hunting Cat Cone, Conus catus, reaches speeds comparable to those of a bullet being fired from a pistol. In a paper recently published online in Current Biology, Joseph R. In addition to producing some of the most potent venoms in nature, cone snails are now known to deliver one of the fastest predatory strikes in the animal kingdom.
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