Conus geographus

Conus geographus, popularly called the geography cone or the geographer cone, is a species of predatory cone snail. It lives in reefs of the tropical Indo-Pacific, and hunts small fish. Although all cone snails hunt and kill prey using venom, the venom of this species is potent enough to kill humans. Specimens should be handled with extreme caution. The variety Conus geographus var. rosea G. B. Sowerby I, 1833 is a synonym of Conus eldredi Morrison, 1955. C. geographus has a broad, thin shell, cylindrically inflated. Geography cones grow to about 4 inches (10 cm) to 6 inches (15 cm) in length. The size of an adult shell varies between 43 mm and 166 mm. The ground color of the shell is pink or violaceous white, occasionally reddish. It has a mottled appearance, clouded and coarsely reticulated with chestnut or chocolate, usually forming two very irregular bands. This intricately brown-and-white pattern is highly prized by shell collectors. The geography cone has a wide, violaceous white or pink aperture and numerous shoulder ridges or spines. The shell is covered with thread-like revolving striae, usually nearly obsolete except at the base. The flattened spire is striated and coronated. In comparison with other species, the shell has a noticeably wider and convex mid-body, with a flattened spire. Its walls are also noticeably thinner and lighter compared to other cone shells of similar length and size. Geography cones are common. They occur in the Red Sea, in the Indian Ocean off Chagos, Réunion, Madagascar, Mauritius, Mozambique and Tanzania. They are indigenous to the reefs of the Indo-Pacific region, except for Hawaii, and off Australia (the Northern Territory, Queensland, Western Australia). C. geographus is a piscivore that dwells in sediment of shallow reefs, preying on small fish. It releases a venomous cocktail into the water in order to stun its prey. Like the other cone snails, it fires a harpoon-like, venom-tipped modified tooth into its prey; the harpoon is attached to the body by a proboscis, and the prey is pulled inside for ingestion. The geography cone is highly dangerous; live specimens should be handled with extreme caution. C. geographus has the most toxic sting known among Conus species and is responsible for more than thirty human fatalities. Yoshiba estimated an LD70 value (in humans) of 0.001-0.003 mg/kg. In two cases of envenomation, only 0.0002-0.0005 mg resulted in severe paralysis. Other figures estimate LD50 values of 0.012-0.03 mg/kg. These estimates make the geographic cone snail the most venomous animal in the world. The venom is a complex mix of hundreds of different toxins that is delivered through toxoglossan radula, a harpoon-like tooth propelled from an extendable proboscis. There is no antivenom for a cone snail sting, and treatment consists of keeping victims alive until the toxins wear off. The geography cone is also known colloquially as the 'cigarette snail', a gallows humor exaggeration implying that, when stung by this creature, the victim will have only enough time to smoke a cigarette before dying.