Turning the Tide Magazine Threatened Species

Creature Feature: Cuttlefish

Summer '24 Newsletter
by AMCS January 10, 2024

Curious Cuttlefish!

“Chameleons of the sea” cuttlefish are renowned for their colour-changing body camouflage and morphing abilities. They can control the 10 million colour cells within their skin to quickly change colour, pattern and texture.

Cuttlefish, despite the name, are not fish but invertebrates related to the octopus, squid and nautilus. They have eight arms and two long tentacles attached to their heads.

There are more than 120 different species of cuttlefish and they can be found in oceans all around the world.

Giant Australian cuttlefish are the largest of all the cuttlefish found only in Australia’s southern coastal waters, from Ningaloo Reef in WA around to Moreton Bay in Queensland.

They are reportedly curious and friendly with divers. Cuttlefish have a large brain-to-body size ratio—among the biggest of all invertebrates — which makes them incredibly intelligent.

The giant Australian cuttlefish has a short life span of just two to four years.

Giant Australian cuttlefish start to congregate to breed in mid-May at Point Lowly in South Australia’s northern Spencer Gulf. This is the world’s only mass gathering of mating cuttlefish. When mating does occur, the couple ‘cuddle’ in a head to head embrace.

Did You Know?

Like octopus, cuttlefish have three hearts and blue blood.

Facts & Figures

COMMON NAME: Giant Australian Cuttlefish
TYPE: Invertebrate
BODY SIZE: 50 to 100 cm
WEIGHT: 5 to 10.5 kg
LIFESPAN (IN WILD): Approx. 2 to 4 years
DIET: Carnivore (fish, crabs, prawns, smaller cuttlefish, and shrimp)
HABITAT: Shallow reefs and marine channels
LOCATION: Endemic to southern coastal waters of Australia, and is found as far north as Moreton Bay (QLD) on the east-coast and on the west-coast up to Ningaloo Reef (WA).
POPULATION TREND: Decreasing (last assessed in 2009). Fluctuating but relatively stable. Assessments since IUCN listing show population recovery, fluctuating to a peak in 2020.