Biodiversity

Australian Biological Resources Study

Species Bank Home

Idiosepius notoides (Family Idiosepiidae)

Southern Pygmy Squid

Distribution

Distribution:

Southern half of Australia from southern Queensland in the east to the midcoast of Western Australia (QLD, NSW, VIC, TAS, SA, WA).

Features:

A tiny cylindrical squid that reaches around 3 cm long. Some males are mature at less than 1 cm long. This squid has two small rounded fins on the rear tip of the body. There are eight arms and a pair of retractable feeding tentacles. The arms and the tips of the feeding tentacles have small suckers with a horny, toothed rim. There is no shell. A large glandular patch occurs on the rear two thirds of the upper body. Colours vary from almost transparent, to iridescent green and yellow, to dark chocolate brown. There are short white lines radiating from around the eyes. The skin is smooth.

Ecology/Way of Life:

Pygmy squids are the smallest of all the cephalopods. They are abundant in seagrass beds in bays and inlets, particularly eelgrass beds (Zostera and Heterozostera). They live deep within the seagrass leaves where they prey on small crustaceans and fish. They are able to push their mouth parts (beak and toothed tongue) deep into their prey, like a mouth on a stalk.

Pygmy squids are ambush predators that hide on the underside of leaves using a special glue gland. This structure is situated on the top of the body and uses two different types of gland cells. One type secretes mucous which allows the squid to glue itself to the underside of leaves. When it wants to detach, it uses matching acid glands to dissolve the mucous. It can attach and detach as many times as it likes. The glue gland allows the squid to rest amongst the leaves without having to be buoyant or constantly swimming. These squid are active both during the day and at night. They position themselves before attacking their prey so that they strike from behind. This way they can quickly bite through the nerve cord while holding the legs and biting bits of their prey away from themselves.

Little is known of the biology of this tiny cryptic squid as it is difficult to observe them deep in seagrass beds. Captive animals have been observed mating where the male attaches small sperm packets to the head and arms of the female. It is not known how she uses or stores these packets. Females lay single round eggs in lines along the underside of seagrass leaves.

Preferred Image

Interaction with Humans/Threats:

There are no commercial or recreational harvests of this tiny squid. They are sometimes mistaken for the juveniles of larger commercial squids, which also hide in seagrass beds.

Further Reading:

Norman, M.D. and A. Reid. 2000. A guide to the squid, cuttlefishes and octopuses of Australasia. Gould League/CSIRO Publishing, Melbourne. 96 pp.

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

Acknowledgments:

Text & map by Mark Norman, Museum Victoria, phtograph by David Paul.

Sponsorship welcomed:

Please Contact ABRS if you wish to discuss sponsoring this or other pages.


Images and Multi-media:  
Attached Image  
image/jpeg 112921 bytes Southern Pygmy Squid using its glue gland to attach to seagrass leaves
Distribution Map  
image/jpeg 38768 bytes Distribution of Southern Pygmy Squid

Return to Species Bank home

SpeciesBank

Key

   Links to another web site
   Opens a pop-up window