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Sepiadarium austrinum (Family Sepiadariidae)

Southern Bottletail Squid



Southern Australia from Brisbane in the east to at least Perth in the west (QLD, NSW, VIC, TAS, SA, WA).


This tiny round squid reaches sizes of only 4 cm in length. It is generally orange or yellow in colour made up of large pale spots scattered over the body, head and arms. It has a pair of small kidney-shaped fins on the sides of the body for the rear two thirds of its length. The eyes are large and the pupils are horizontal slits. There are eight arms and two retractable feeding tentacles. The arms and clubs at the tips of the feeding tentacles have numerous tiny suckers, each armed with a horny, toothed rim. This squid lacks an internal shell. The underside of the head and body are covered in regular small rounded glands that produce slime (mucous).

Ecology/Way of Life:

These small squids live on sand and mud habitats in coastal waters, often near seagrass beds. They hide in the sand during the day by wriggling their body into the sand and using two arms to rake sand grains over their head and body. At night, they emerge to hunt for small crustaceans, particularly isopod crustaceans. They have a special defense strategy. If attacked they squirt a large amount of slime from the glands under their body. The slime appears to contain chemicals that deter or scare off the predators. Its chemical composition is still unknown.

Mating consists of males grabbing any passing females and placing sperm packets in a special pouch below the female's mouth. If the female has already mated the courting male uses a special modified arm that scoops out the sperm of any previous males. Females store sperm until ready to lay their eggs. Eggs are laid in clumps, glued together and covered in sand grains, usually at the bases of seaweeds or seagrasses.

There is still little known of the biology and behaviour of this squid.

Preferred Image

Interaction with Humans/Threats:

There is no fisheries or recreational harvest of this tiny squid. As the chemical composition of the slime is unknown, people should avoid handling these squids.

Further Reading:

Norman, M.D. 2000. Cephalopods: A world guide. ConchBooks, Hackenheim, Germany.


Text & map by Mark Norman; photographs by Mark Norman and David Paul.

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Images and Multi-media:  
Attached Image  
image/jpeg 75047 bytes Southern Bottletail Squid showing fins and funnel
Attached Image  
image/jpeg 197393 bytes Southern Bottletail Squid buried in sand
Distribution Map  
image/jpeg 37529 bytes Distribution of Southern Bottletail Squid

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