1. Cuttlefish

2. Fascinating cuttlefish
Despite their common name, cuttlefish are not fish but mollusks.
The eye of the cuttlefish, like that of the squid, has a very similar design to our own.
Cuttlefish blood looks blue-green because it uses the pigment hemocyanin to carry oxygen.
Cuttlefish fish have the remarkable ability to rapidly alter their skin color at will.
Cuttlefish eat small molluscs, crabs, shrimp, fish and other cuttlefish.
The cuttlefish has tentacles along with a mantle that had a calcium based ‘cuttlebone’ which forms the shape of the body.
They have eight arms and two tentacles, which consist of denticulated suckers. Between the tentacles, one can find a beak-like mouth.
The eye of the cuttlefish

3. Distinguishing features
The cuttlefish is so called because they have a bone in the middle of their bodies, known as a cuttlebone, filled with gas, which is used as a buoyancy control device.
Averaging about 30cm in length (giant cuttlefish can grow up to 100cm), they have eight arms and two prehensile (capable of grasping) tentacles around their parrot-like beak.
Their eyes are remarkably similar in construction to human eyes and there is an unmistakable feeling that you are dealing with a creature of intelligence when you find yourself in a staring contest with a cuttlefish
Mating cuttlefish align their bodies head to head so the male can transfer a sealed package of sperm into a pouch beneath the female's mouth. The female then scurries off to a quiet place where she draws eggs from her cavity and passes them over the sperm, thereby fertilizing them.

4. Diving with cuttlefish
Unlike their squid and octopus cousins, baby cuttlefish are already highly developed and independent straight hatching.
The main predators of cuttlefish are sharks, fish and other cuttlefish. Dolphins also attack cuttlefish but strangely eat only the heads.
Cuttlefish are widely distributed according to species. For example the European common cuttlefish is found all along the eastern Atlantic from Scandinavia to South Africa and the Mediterranean. Most other species, such as the flamboyant cuttlefish, are found in Asian waters and in Australasia. They are not found in American waters.

5. Cuttlefish reproduction
Adult cuttlefish are hard to sex and the only 100% reliable way to sex a live one is to see it mating or laying eggs.
However, a male cuttlefish might aggressively display to a reflection of itself in a mirror. The aggressive display of cuttlefish consists of a vivid zebra stripped pattern, bulging eyes, and often lining up parallel to its reflection.
Since sexing techniques are far from reliable, the best way to get mated cuttlefish is to raise a group together in a large aquarium. They can tell each others sex by sight and will mate readily when they are old enough to do so.

6. Pictures