Facts About Cuttlefish:

Cuttlefish are cephalopods that are found in shallow temperate and tropical waters. While they may be seen in aquariums and at research institutions in the U.S., wild cuttlefish are not found in U.S. waters. 

Cuttlefish are cephalopods, which means they are in the same class as octopus, squid, and nautilus. These intelligent animals have a ring of arms surrounding their head, a beak made of chitin, a shell (although only the nautilus has an exterior shell), a head and foot that are merged, and eyes that can form images.

The cuttlefish has two long tentacles that are used to quickly grasp its prey, which it then manipulates using its arms. Both the tentacles and arms have suckers.

There are over 100 species of cuttlefish. These animals vary in size from a few inches to several feet in length. The giant cuttlefish is the largest cuttlefish species and can grow to over 3 feet in length and more than 20 pounds in weight.

Cuttlefish have a fin that goes around their body, which looks like a skirt. They use this fin for swimming. When quick movement is needed, they can expel water and move by jet-propulsion. 

Cuttlefish can change their color according to their surroundings. This happens thanks to the millions of pigment cells, called chromatophores, that attach to muscles in their skin.  When these muscles are flexed, the pigment released into the cuttlefish's outer skin layer and can control the cuttlefish's color and even the pattern on its skin. This coloration is also used by males for mating displays and to compete with other males.

Cuttlefish have short lifespans. Cuttlefish mate and lay eggs in spring and summer.  Males may put on an elaborate display to attract a female. Mating occurs with the male transferring a sperm mass to the female's mantle, where it is released to fertilize the eggs. The female attaches groups of egg onto objects (e.g., rocks, seaweed) on the seafloor. The female stays with the eggs until they hatch, but both the male and female die shortly afterward. Cuttlefish are sexually mature at 14 to 18 months of age and only live 1 to 2 years.

Cuttlefish are active predators who feed on other mollusks, fish, and crabs. They may also feed on other cuttlefish. They have a beak in the middle of their arms that they can use to break the shells of their food.

When threatened, cuttlefish may release an ink -- called sepia -- in a cloud that confuses predators and allows the cuttlefish to get away. This ink historically was used for writing and drawing, can be used to treat medical conditions and is also used as a food coloring. 

Within their bodies, cuttlefish have a long, oval bone called a cuttlebone. This bone is used to regulate buoyancy using chambers that may be filled with gas and/or water depending on where the cuttlefish is in the water column. Cuttlebones from dead cuttlefish may wash up on shore and are sold in pet stores as a calcium/mineral supplement for domestic birds.

Cuttlefish can't see color but they can see polarized light, an adaptation which may aid in their ability to sense contrast and determine what colors and patterns to use when blending into their surroundings.  The pupils of cuttlefish are W-shaped and help control the intensity of light entering the eye.  To focus on an object, a cuttlefish changes the shape of its eye, rather than the shape of its eye's lens, as we do.