Because all Conus snails are venomous and capable of "stinging" humans, live ones should be handled with great care or preferably not at all. The species most dangerous to humans are the larger ones which prey on small bottom-dwelling fish. The other species hunt and eat marine worms or mollusks. Cone snails use a hypodermic-like modified radula tooth and a venom gland to attack and paralyze their prey before engulfing it. The tooth is sometimes likened to a dart or a harpoon. It is barbed and can be extended some distance out from the mouth of the snail, at the end of the proboscis.
Cone snail venoms are mainly peptides. The venoms contain many different toxins that vary in their effects; some are extremely toxic. The sting of small cones is no worse than a bee sting, but the sting of a few of the larger species of tropical cone snails can be serious, occasionally even fatal to human beings. In recent years cone snail venom is showing great promise as a source of new, medically important substances.
Read more about Conus: Distribution and Habitat, Shell Description, Life Habits, Species