The word cuttlefish might be new to you. They look similar to octopus and squid, and are in many ways the same, for example they can both change their color and skin pattern. Cuttlefish are cephalopods (like octopi and squid).
This particular cuttlefish is not toxic, or dangerous at all (except when you eat them you get bad breath :D). There is, however one species that is toxic, but we will be focusing on just the broadclub for now.
This cuttlefish can change colors, both to hide from predators, and to compete for a female against other males. Cuttlefish have been ranked as one of the oceans smartest creatures because of their understanding of colors and patterns (cuttlefish have the biggest brain to body size ratio of any other invertebrate). These cuttlefish change their colors in a complicated way. There are something called chromatophores inside their skin, they stretch this chromatophores to form different colors or patterns.
Diet: Broadclub cuttlefish will eat most small fishes or invertebrates, like most other cephalopods. The prey is killed with a bite from their beak (their beak is their mouth, concealed under the cuttlefish’s arms). Their prey is found with the cuttlefishes acute seeing and hearing. Although the invertebrate can’t ‘hear’ at all it can sense sound through little hair cells on its body. They have been observed “mesmerizing” their prey with elaborate color displays before attacking.
Defenses: The Broadclub cuttlefish has a hard outer shell, but this does not protect them from large predators, predators that can easily piece the shell. They also are experts at blending in, changing both skin pattern and color. To warn off predators they sometimes make their skin flash in bright and confusing patterns. These cephalopods do have an ink sack that they use to confuse predators by squirting it into the water, unlike the Blue Ringed Octopus.
Appearance: This is the second largest cuttlefish species in the world, reaching up to 50 cm long and 10 kg. When cuttlefish aren’t changing color and pattern to blend in, they are most commonly seen as a white body with thick pinkish rings going down the body. It has eight arms, or tentacles, and does not have a hard outer shell.
Reproduction: The broadclub mates between January and May. The Males guard their coral head where the female will lay her eggs. The eggs take about 40 days to hatch. The hatchlings often hide in the coral and mimic things such as mangrove leaves.
Range: Indian Ocean, Philippine Sea, South and East China Sea, and areas around Japan. Also found in the Malacca strait and Melanesian islands, and in many areas around Australia including the Great Barrier Reef.
Cites:
http://animals.about.com/od/molluscs/p/molluscs.htm
http://fyeahseacreatures.tumblr.com/post/8283247799/broadclubcuttlefish
http://marinebio.org/species.asp?id=1364