Conus nocturnus is a species of sea snail, a marine gastropod mollusk in the family Conidae, the cone snails and their allies.
Like all species within the genus Conus, these snails are predatory and venomous. They are capable of "stinging" humans, therefore live ones should be handled carefully or not at all.
The size of the shell varies between 45mm86mm. The pattern of the markings are essentially the same as in Conus marmoreus, but the chocolate-color coalesces into two broad irregular bands within which the triangular white spots appear only occasionally. In Conus deburghiae the surface is sometimes granular in the revolving lines, and the nodules are compressed.[1]
This marine species occurs off Madagascar, off Mauritius, Sri Lanka, the Moluccas and New Guinea.