Conus is a large genus of small to large predatory sea snails, marine gastropod molluscs, with the common names of cone snails, cone shells or cones.
Geologically speaking, fossils of the genus are known from the Eocene to the Holocene periods. Conus species have shells that are shaped more or less like geometric cones. Many species have colorful patterning on the shell surface. Conus snails are mostly tropical in distribution.
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 smaller species mostly hunt and eat marine worms. Cone snails use a hypodermic needle-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.
The bright colors and patterns of cone snails are attractive to the eye, and therefore people sometimes pick up the live animals and hold them in their hand for a while. This is risky, because the snail often fires its harpoon in these situations. In the case of the larger species of cone snail, the harpoon is sometimes capable of penetrating the skin, even through gloves or wetsuits.
The sting of many of the smallest cone species may be no worse than that of a bee or hornet sting, but in the case of a few of the larger tropical fish-eating species, especially Conus geographus, Conus tulipa and Conus striatus, a sting can sometimes have fatal consequences. Other dangerous species are Conus pennaceus, Conus textile, Conus aulicus, Conus magus and Conus marmoreus. But according to Goldfrank’s Toxicologic Emergencies, only about 15 human deaths can be confidently attributed to cone snail envenomation. Edited fro Conus and NatGeo