Seen on almost every dive or snorkel are the cephalopods.  This class of animals including the octopus, squid and cuttlefish are soft-bodied moluscs and the most intelligent of all invertebrates. As their name "Cephalopod" suggests (Cephalopod directly translates as "head-foot") their heads are partially or fully fused with the foot. Their eyes are considered very complex and provide similar vision to that of humans. They can also change their colours rapidly with nerve-activated pigment cells (one of the most beautiful things is watching them change their colour from red to white to stripey to black to yellow).

OctopusOctopus
With no bones the octopus can squeeze into tiny places quickly and easily. With 8 tentacles in total, a beak like jaw, a huge head enclosing all their main organs, and they large eyes the charasmatic octopus is one of the most enjoyable sights in Sydney.

CuttlefishCuttlefish
Cuttlefish belong to the class of Cephalopods. They have an internal shell (cuttlebone), eight arms and and two "sucker" tentacles which they use to grab their prey.
Cuttlefish are fun to interact with and common in Sydney - if you can spot them!

SquidSquid
The squid family has over 400 species, with the largest species  reaching an incredible size of 13metres long. Most seen in Sydney are much smaller. With eight arms, two longer feeding tentacles, a large set of eyes and a large brain, the squid are a beautiful animal seen quite often at a variety of sites.