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. 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.

The closeup of the anterior end below shows the siphon at right. Just to the left of the siphon barely visible peaking out from beneath the shell is the mouth, and the white tentacle to the left of that is a sensory tentacle with a black eye at the junction between white and brown.

A young specimen has a shell with a pattern of tent markings, similar to that of one of the tented cones such as Conus textile. I suspect that deaths reportedly caused by C. textile may actually have been one of these.

Created 4 July 2009
Updated 8 October 2016

Return to cones

Kwajalein Underwater home