The Southern Bobtail Squid has not yet been formally named and little is known of its exact biology and distribution, but has been placed in the Sepiola

Sepiola

Sepiola is a genus of bobtail squid comprising around 15 species.-Species:*Genus Sepiola**Sepiola affinis, Anagolous Bobtail**Sepiola atlantica, Atlantic Bobtail**Sepiola aurantiaca, Golden Bobtail...

genus. It has been collected in reef

Reef

In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....

 areas along most of the Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

n south coast. The squid

Squid

Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...

 uses bioluminescent bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 situated in a special circular light organ in the mantle cavity to conceal itself from predators. The organ produces the same amount of light as the mantle blocks thus canceling the squid's silhouette from below.

Southern Bobtail Squid grow to 20mm in length. They have small rounded fins on the sides of their mantle. They have two rows of suckers on each arm. Both the arms and mantle are covered in large dark brown spots (chromatophores).