Giant Australian cuttlefish (Sepia apama)
The giant Australian cuttlefish (Sepia apama) is the world’s largest cuttlefish, and, like many other cephalopods, it is able to camouflage itself exceptionally well. By changing its skin colour and texture, the giant Australian cuttlefish can convincingly disguise itself against its surrounding environment almost instantaneously. Cephalopods, which literally means ‘head-footed’, are a class of marine molluscs which, along with cuttlefish, includes squid, octopuses and nautiluses. Unlike other molluscs, cephalopods have a closed circulatory system, where blood is contained in vessels, and a highly developed nervous system with a large brain.
The giant Australian cuttlefish has eight arms and two extended tentacles, which are used for mating and catching prey, as well as to transform and camouflage the shape of the body. The giant Australian cuttlefish is reddish brown, with white bars and spots on the arms and the mantle, and pale fins.
All cephalopods, and in particular cuttlefish species, have large, highly-developed eyes, and can detect very low light levels, vital in detecting prey and avoiding predation at night. Cephalopods are widely considered to be the most intelligent group of invertebrates,with one of the largest brain-to-body size ratios of any invertebrate.