Cephalopods
Southern Calamari
Sepioteuthis australis
A swift, colour-changing hunter of coastal reefs and seagrass meadows. Southern calamari live fast, grow quickly and bring remarkable movement to the Great Southern Reef.
Scientific Name
Sepioteuthis australis
Group
Cephalopod mollusc
mantle length
Up to 50 cm
Lifespan
Usually less than a year
Feeding
Fish and crustaceans
Identification
Recognising southern calamari
Look for an elongated mantle bordered by broad, diamond-shaped fins. These fins extend almost the full length of the body and are widest around the middle.
Colour is changeable: individuals can appear orange-brown, pale with dark bands or almost transparent. Body shape is a more reliable starting point than colour alone.
Look for these four features:
long, tapered mantle
full length fins
large eyes
arms & tentacles
Distribution & Habitat
Life in the coastal shallows
Southern calamari occur around Australia’s southern coastline, with a range extending from the southern Great Barrier Reef to Ningaloo in Western Australia. They also occur around New Zealand’s North Island.
Shallow reefs, sandy areas and seagrass beds are familiar habitat. They are commonly encountered in the upper 10 metres of the water column.
Feeding Ecology
A Hunter after dark
Southern calamari feed on small fish and crustaceans, and may also eat other squid. These fast-growing predators need a steady supply of food throughout their short lives.
They are often active at night, although they can also be seen during the day. Divers sometimes encounter them approaching torchlight to hunt prey gathered in the beam.
crabs
Crabs are among the prey taken from the seafloor.
Crustaceans
Krill and other crustaceans are also on the menu.
Other squid
Their diet can include fellow cephalopods.
Movement & Defence
Built for a quick escape
Southern calamari use jet propulsion for sudden bursts of speed. Water drawn into the mantle cavity is forced out through a muscular siphon, pushing the animal in the opposite direction.
When threatened, they can release ink as a decoy while making their escape. Rapid changes in colour add another layer to their remarkable defensive repertoire.
water intake
DRAW WATER IN
Water enters through openings around the head, filling the mantle cavity.
Jet propulsion
JET TO ESCAPE
The mantle contracts, forcing water out through the siphon and pushing the squid the other way.
when threatened
LEAVE AN INK DECOY
Ink released through the siphon can distract a predator while the squid jets away.
Simplified side views, not to scale. Ink release is a defence, not a stage of every jet. How squid move · Stanford Gilly Lab ↗
Reproduction & Development
A short Life. A new Generation.
Southern calamari gather to breed in shallow coastal habitats. Females attach egg capsules to vegetation and other suitable structures, sometimes forming communal egg masses.
Rather than laying all their eggs at once, females can spawn repeatedly over several months. Breeding timing varies with location and conditions; in Tasmania, spawning is strongest from spring into summer, with some activity throughout the year.
The young hatch as tiny squid and swim up into the water column. Growth is rapid, with temperature and food availability helping shape the pace of their lives.
conservation & Responsible Fishing
small windows.
lasting consequences.
A short lifespan makes southern calamari populations strongly dependent on successful spawning and the survival of each new generation. Poor recruitment combined with heavy fishing can quickly affect local abundance.
Protecting spawning aggregations and coastal habitat matters. Seasonal closures and catch limits are designed to reduce fishing pressure, but rules and stock condition differ between regions.
• check local fishing rules
Follow the current limits and spawning closures where you fish.
• Leave egg masses undisturbed
Observe without handling eggs or damaging the vegetation supporting them.
Regional Spotlight • tasmania
Recovery is not guaranteed
The 2023–24 assessment, published in September 2025, classified southeast Tasmania’s southern calamari stock as depleted and the northern stock as depleting.
These are regional fishery assessments—not a species-wide extinction classification. They show why a blanket description of calamari as a “sustainable resource” needs care.
affected by the harmful algal bloom
regional spotlight • south Australia
Southern calamari have been severely affected by the harmful algal bloom that began in South Australia in March 2025. SARDI’s September 2026 assessment recorded major declines in catches and catch rates in Gulf St Vincent and around Kangaroo Island. Dive surveys found no calamari eggs at surveyed Gulf St Vincent sites during October–December 2025 and June 2026.
Declines also extended across Spencer Gulf. Some improvement in catch rates was recorded in July and August 2026, but levels remained below the historical baseline. These early signs do not establish full recovery; continued monitoring is needed to understand how populations respond.
Assessment: September 2026 · Read the SARDI report (PDF) · Latest impact updates
watch southern calamari
hunting by torchlight
See the movement, colour and hunting behaviour of southern calamari.
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