PORT PHILLIP BAY


Southern Pygmy Squid 

Idiosepius notoides Berry, 1921

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 free (unfused) from head. Non-hectocotylised arm sucker arrangement biserial. Both ventral arms of males hectocotylised: right arm flattened, wide, with protective membranes, sometimes with transverse ridges and grooves, distal tip of left ventral arm bilobed; both arms mainly without suckers. Tentacle club with two to four suckers in transverse rows. Internal shell absent. Glandular oval attachment organ on dorsal posterior end of mantle.
Female mantle length to 25 mm. Male mantle length to 16 mm, some maturing at less than 10 mm.

Taxonomy

Phylum:
Mollusca
Class:
Cephalopoda
Subclass:
Coleoidea
Order:
Sepiolida
Family:
Idiosepiidae
Genus:
Idiosepius
Species:
notoides

General Description

Tiny cylindrical, free-swimming squid. Small pair of rounded fins on the rear tip of body. Large glandular patch on the rear two thirds of upper body. Colour varies from almost transparent, to iridescent green and yellow, to dark chocolate brown. Short white lines radiate from around the eyes. Female mantle length to 3 cm. Male mantle length to 16 mm, some maturing at less than 1 cm.

Biology

Pygmy squids are the smallest of all the cephalopods. This squid is abundant in seagrass beds in bays and inlets, particularly eelgrass beds (Zostera and Heterozostera). It lives deep within the seagrass where it attaches to the underside of leaves using special glue glands situated on the top of its body. The glue gland allows the squid to maintain position without having to be buoyant or constantly swim. Pygmy squids are ambush predators that prey on small crustaceans and fish. They are able to push their mouth parts (beak and toothed tongue) deep into their prey. They are active both during the day and night. Females lay single round eggs in lines along the underside of seagrass leaves.

Habitat

Seagrass beds in shallow bays and inlets to a depth of 20 m.

Seagrass meadows

Distribution guide

Southern Australia.

Species Group

Octopuses and allies Squid

Depth

Shallow (1-30 m)

Water Column

On or near sea floor

Max Size

1 cm

Diet

Carnivore

Harmful

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

Commercial Species

No

Global Dispersal

Native to Australia

Species Code

MoV 2829

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 Pygmy Squid, Idiosepius notoides, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 18 Oct 2017, http://portphillipmarinelife.net.au:8098/species/7835

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