STRATEGY FOR RAPID IMMOBILIZATION OF PREY BY A FISH-HUNTING MARINE SNAIL

SOME venomous animals capture prey with remarkable efficiency and spee d. The purple cone, Conus purpurascens, uses two parallel physiologica l mechanisms requiring multiple neurotoxins to immobilize fish rapidly : neuromuscular block(1), and excitotoxic shock, The latter requires t he newly characterized peptide kappa-conotoxin PVIIA, which inhibits t he Shaker potassium channel(2-4), and delta-conotoxin PVIA(5), which d elays sodium-channel inactivation, Despite the extreme biochemical div ersity in venoms, the number of effective strategic alternatives for p rey capture are limited. How securely prey is initially tethered may s trongly influence the venom strategy evolved by a predator.