Related to octopus, squid and nautiluses, cuttlefish are considered one of the most intelligent invertebrates.

Ovalbone cuttlefish - Sepia elliptica - Photo by Kylie Pawlow

They have the largest brain-to-body size ratio of all invertebrates and are masters of camouflage. They contain chromatophores, iridiphores, leucophores which allow them to rapidly change their colour, pattern and shape (within 1 second). It is believed that this is not only used as camouflage, but also as a method of communication.

Most people only encounter the white, oval cuttlebone of these interesting animals along the beach.

Similar to octopus, cuttlefish produce a dye that can be expelled into the water to confuse predators. The rich brown colour of the ink used to be collected to make a dye with the name "Sepia" derived from the genus name.