Cuttlefish

Did you know that a cuttlefish is not actually a fish? It's a mollusk! They are actually more closely related to snails then they are to fish. Like squids, octopi, and nauteluses, the cuttlefish is a cephalopod. Members of class cephalopoda have been dated back 500 million years!

There are currently 120 species of cuttlefish recognized, all of which live in shallow tropical and temperate waters around Europe, Asia, Africa and Australia. Cuttlefish have a pretty interesting mechanism built in to their bodies: the cuttlebone. Made primarily of aragonite, these structures act as buoyancy mechanisms, enabling the cuttlefish to float at a steady, desirable level. The existence of this bone is also what prevents the cuttlefish from surviving at deep depths, as they will implode when there is too much pressure. Cuttlebones are very rich in calcium, and are often given to caged pets like parakeets and reptiles as supplements.

Cuttlefish have the ability to change their skin color in order to blend in with their surroundings. They do this with help from three special types of skin cells: chromatophores, iridophores, and leucophores, all of which reflect light in different ways to cause the camouflaged effect. With their stealthy camouflage in place they are  able to ambush their prey, which is caught using their eight arms and two tentacles, all of which possess a pad at the end which is covered in powerful suckers.Their diets consist of fish, crustaceans, and even other cuttlefish. They also make use of their color changing skills in mating displays and to hide from predators. Cuttlefish have one of the largest body size to brain ratios among invertebrates, and are considered to be one of the most intelligent of all invertebrates. Their cleverness and thinking skills are pretty astounding when you realize that many of their mollusk relatives don't even possess brains!