The Cuttlefish is one of the most intelligent invertebrates in the world and contrary to what the name suggests the Cuttlefish is actually a mollusk and is part of the same family as squids and octopus's.  Like its close relatives the Cuttlefish utilities internally produced ink and also has a neuro-toxin that can be used on prey and rivals alike and is even lethal to the blue ringed octopus.

Spanning a large portion of the worlds oceans from western Europe to the coast of Australia these interesting mollusks prefer tropical warm water climates and are primarily found in warm shallows but have occasionally been known to inhabit depths of up to 600 meters. The only place you won't fins Cuttlefish is in the waters of the Americas, its currently believed that the reason for this is because the water is now too cold.

[caption id="attachment_1735" align="alignnone" width="500" caption="A Cuttlefish displaying its unique colors"]A Cuttlefish displaying its unique colors[/caption]

The Cuttlefish boast a variety of unique and intriguing features, the eyes of the Cuttlefish for example stand out as particularly because of their distinct 'w' shaped pupil. The unique formation of the pupil provides the Cuttlefish with a very well developed sight that focus's on contrast rather than color which works especially well in their dark underwater environment.

Another notable feature of the Cuttlefish is its skin. The Cuttlefish is a master of camouflage and has unique skin cells that can change pigment to create a vast array of colors including amazing metallic green, blue and yellow. With this ability the Cuttlefish can even influence the color of light reflected from its skin and even the polarization of light which can be used to signal others.

[caption id="attachment_1736" align="alignnone" width="500" caption="Cuttlefish"]Cuttlefish[/caption]

Mammal's blood is red because it contains a protein called hemoglobin which contains iron, on the other hand the Cuttlefish's blood is green because instead of containing hemoglobin it contains hemocyanin which contains copper. Color is not the only difference the Cuttlefish's blood has however as because of the type of blood it has it must pump blood much faster than a mammal and as a result of this the Cuttlefish has 3 hearts.

The preferred diet of the Cuttlefish is crabs and fish. Being a master hunter the Cuttlefish uses its camouflage ability to get close to its prey before launching 2 long tentacles from inside its beak in the center of its arms and proceeds to drag the prey in and administer neuro-toxin via its beak.