Conus geographus Linnaeus, 1758 Geography cone, 129mm Conus geographus is the largest of the fish-eating cone shells and is also the most dangerous. Its venom has adapted to become powerful enough to quickly stun or kill a prey fish. It wouldn't do the cone much good if the fish were stung and escaped, only to die somewhere else. In addition to having highly virulent venom, it also has an aggressive attitude.
Deadly sea snail uses weaponised insulin to make its prey sluggish
While most cone shells will retract within the shell when disturbed and show little or no inclination to sting humans, Conus geographus will frequently start waving about its stinger looking for a victim when it is picked up. You have to watch this one carefully. They live in a variety of seaward reef and lagoon habitats, and like many other cones, are nocturnally active.
A geography cone snail (Conus geographus) The human lethal dose for its venom has been estimated at just 0.029-0.038mg for every kg of body mass. 65% of human stinging cases are fatal without medical attention – although only 36 such fatalities have been recorded since 1670. (Credit: Jeff Rotman/NPL)