PORT PHILLIP BAY


Southern Bobtail Squid 

Euprymna tasmanica (Pfeffer, 1884)

View scientific description and taxonomy

Scientific Details

Ten circumoral appendages, eight arms and two ventrolateral tentacles. Mantle cavity with three openings to exterior. Arms and clubs at the tips of the tentacles with numerous suckers, each armed with a horny, toothed rim. Tentacles contractile and retractile into pockets between arms III and IV. Mantle edge near mantle cartilages straight. Fin not joined posteriorly. Dorsal border of mantle fused with head. Non-hectocotylised arm sucker arrangement tetraserial. Dorsal and ventral rows of suckers on arms II to IV in males enlarged. Left dorsal arm of males hectocotylised. Base of hectocotylus with 29 to 38 normal suckers, replaced by distal half bearing approximately 70 modified columnar suckers in two double rows, each consisting of a fleshy columner structure with slit-like opening, a thickened lip (or cap) and a chitinous ring. Tentacle club with many hundreds of similar-sized, minute suckers. Internal shell rudimentary, straight and chitinous.
Colour iridescent green with large dark brown spots (chromatophores) scattered over the body, head and arms.
Mantle length to 40 mm.

Taxonomy

Phylum:
Mollusca
Class:
Cephalopoda
Subclass:
Coleoidea
Order:
Sepiolida
Family:
Sepiolidae
Genus:
Euprymna
Species:
tasmanica

Other Names

  • Southern Dumpling Squid

General Description

Small round, bottom living squid. Large pair of rounded fins on sides of body encompassing the rear two thirds of the body. Iridescent green in colour with large dark brown spots (chromatophores) scattered over the body, head and arms. Mantle cavity (underneath the body) contains a large, butterfly-shaped light organ. Mantle length to 4 cm.

Biology

These small squids bury in the sand during the day, emerging at night to hunt for small shrimp and fish. The skin on the upper head and body of this squid is covered in mucous glands that can be used to glue a coat of sand over the whole animal. This allows the squid to remain camouflaged against the sand background. At night this squid uses a light organ in its gill cavity to cancel its silhouette. The light organ contains special glowing bacteria that are fed sugars by the squid in return for making light. By cancelling its silhouette the squid is able to remain undetected as it swims above upward-looking predators. Females lay round orange-cream eggs in clumps.

Habitat

Sand and mud habitats in shallow coastal waters, often near seagrass beds to a depth of at least 144 m.

Seagrass meadows

Soft substrates

Distribution guide

Southern Australia.

Species Group

Octopuses and allies Squid

Depth

Shallow (1-30 m)
Deep ( > 30 m)

Water Column

On or near sea floor

Max Size

4 cm

Diet

Carnivore

Harmful

Potential to bite, especially if handled. Venom status unknown.

Commercial Species

No

Global Dispersal

Native to Australia

Identify

Conservation Status

  • DSE Advisory List : Not listed
  • EPBC Act 1999 : Not listed
  • IUCN Red List : Not listed

Author

article author Finn, J.K.

Dr. Julian Finn is a Senior Curator of marine invertebrates at Museum Victoria.

Author

article author Norman, M.

Dr. Mark Norman is Head of Sciences at Museum Victoria.

citation

Cite this page as:
Finn, J.K. & Norman, M., 2011, Southern Bobtail Squid, Euprymna tasmanica, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 23 Sep 2017, http://portphillipmarinelife.net.au:8098/species/3930

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