“The cuttlefish is the reef’s master of disguise — it can change colour and texture in an instant, becoming whatever the moment requires.”
Cuttlefish of the Great Barrier Reef – The Reef’s Colour-Changing Cephalopod
The cuttlefish is one of the most remarkable animals on the Great Barrier Reef. Though related to squid and octopus, it has a unique charm — it moves through the water in a hovering, lateral undulation that feels almost contemplative, all while performing a continuous colour show across its skin that leaves observers genuinely astonished.
About Cuttlefish
Cuttlefish are cephalopods, the class of molluscs that also includes octopus and squid. Unlike octopus, they have an internal shell (the cuttlebone) that provides buoyancy and allows them to hover at any depth with minimal energy expenditure.
Their skin contains three types of specialised cells — chromatophores (colour), iridophores (iridescence), and leucophores (white). Chromatophores are controlled by nerves and muscles, so colour patterns can change in a fraction of a second, while iridophores and leucophores reflect light to add sheen and white. This creates a living, moving display of colour and pattern used for camouflage, communication, and hunting.
Cuttlefish have large brains for their body size, are among the most intelligent invertebrates, and display complex behaviours including problem-solving, individual recognition, and social communication.
Behaviour and Hunting
Cuttlefish are ambush predators, primarily hunting small crustaceans, fish, and other molluscs. Their hunting technique is extraordinary — they approach prey while rippling colour hypnotically across their body (possibly to disorient it), then strike with two fast tentacles from close range.
They’re generally approachable on the reef and are often curious about divers, sometimes changing their patterns in response to being watched.
Quick Facts About Cuttlefish
- Scientific group: order Sepiida, family Sepiidae
- Main Great Barrier Reef species: broadclub cuttlefish and flamboyant cuttlefish
- Found in: coral slopes, rubble, sand and seagrass
- Diet: crustaceans, small fish and other molluscs, caught with two fast tentacles
- Size: the broadclub cuttlefish grows to about 50 cm long; the flamboyant cuttlefish is much smaller
- Lifespan: short; adults usually die soon after breeding
Scientific Classification
- Kingdom: Animalia
- Phylum: Mollusca
- Class: Cephalopoda
- Order: Sepiida
- Family: Sepiidae
- Conservation status: broadclub cuttlefish – Data Deficient (IUCN)
Cuttlefish of the Great Barrier Reef
- Broadclub Cuttlefish (Ascarosepion latimanus, formerly Sepia latimanus) – the cuttlefish most often seen by snorkellers and divers
- Flamboyant Cuttlefish (Ascarosepion pfefferi, formerly Metasepia pfefferi) – a small, brightly coloured species that walks across sand and rubble
Not to be confused with the giant Australian cuttlefish (Ascarosepion apama), which lives along the southern Australian coast and is not found on the Great Barrier Reef.
Identification Notes
A cuttlefish has eight arms, two longer feeding tentacles, a fin running around the edge of its body and an internal cuttlebone. Small bumps in its skin, called papillae, can be raised or flattened to change its texture.
Learning about reef animals in class? We help schools, universities and study groups plan educational trips to the Great Barrier Reef. Depending on the program, groups can enjoy guided snorkelling and marine biology presentations.
Great Barrier Reef Educational Groups →
Where to See Cuttlefish
Cuttlefish are found in sandy, seagrass, and reef environments throughout the Great Barrier Reef. They’re often seen by day hovering near coral overhangs and rubble zones, and also on night dives.
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FAQs
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