A cuttlefish is a type of mollusk called a Cephalopod, which is a mollusk with a highly developed and centralized nervous system. Similar to octopuses, squids, and nautiluses, cuttlefish are arguably among the smartest invertebrates with the largest brain-to-body size ratio of all invertebrates. They have an internal shell called a cuttlebone, which is porous and allows the animal to maintain buoyancy. They have a typical life expectance of one to two years.
Cuttlefish are remarkable for their ability to color change at will, using a set of specialized, pigmented skin cells and nerve cells, which interact to expand and contract, exposing various pigments as needed. This color change can be used for camouflage, communication between each other, and as a warning to predators.
Cuttlefish utilize neurotoxins produced by bacteria in their saliva as defense and for paralyzing prey. Some species, such as the flamboyant cuttlefish, have toxins as lethal as that of the blue-ringed octopus
The flamboyant cuttlefish (Metasepia pfefferi) was reared successfully for the first time by aquarists here at the Long Island Aquarium.
There are roughly 120 species of cuttlefish currently known