Left: Arms and tentacles of the giant Australian cuttlefish. Right: Sepia officinalis. Images courtesy Andy Murch (http://elasmodiver.com)

Like its cephalopod relatives, the cuttlefish contains an ink sac that it uses to escape predators ("NOVA," 2007). The cuttlefish is most commonly recognized for its ability to change its skin color and texture almost instantly. It does this for camouflage purposes as well as social purposes, such as mating displays. Cuttlefish are considered to have the most sophisticated form of camouflage in the Animal Kingdom (Chiao et al., 2005). Cuttlefish achieve their vast array of body patterns through the use of thousands of chromatophores located in their mantle ("NOVA," 2007). Cuttlefish are important to humans for several reasons. They are important in world fisheries, as 200,000 metric tons of cuttlefish are caught for human consumption each year. Furthermore, artists have used cuttlefish ink, sepia, for hundreds of years (Roper, 2008). Perhaps their most important contribution to humans is their usefulness in studying camouflage. They are model organisms for studying camouflage because they can quickly change their skin rapidly. The most common species of cuttlefish used for research is the European cuttlefish, Sepia officinalis (Shohet et al., 2007).