The southern calamari belongs to the squid family Loliginidae, and is the most common squid found in coastal bays. They can be identified from other squid species by having an appearance halfway between a squid and a cuttlefish. Similarly to the cuttlefish, they have 10 arms, two of which are extendable and have club-shaped ends covered in suckers. The head and slender body are typical of a squid but have a single continuous fin extending around the entire body, rather than being diamond-shaped and located in the rear half of the body as in squids. They also have the typical squid ‘pen’ running underneath the back, a translucent feather-shaped structure that is not calcified like cuttlebone but made of cartilage. Similarly to other cephalopods, the southern calamari uses jet propulsion for locomotion, and when disturbed they are capable of squirting out ink in defence to confuse predators.
Unlike other large cephalopods, the southern calamari prefer open water habitats and frequently form small schools of up to a dozen individuals over seagrass meadows, kelp beds and reefs to depths of 100 metres. They are also attracted to man made structures like rock breakwaters, jetty pylons, and boat moorings. During the day their slender, pale bodies blend in with the surface waters, at night descending to the sea floor where their colours darken. They are generally seen by divers at night time as this is when they are more active and are attracted to divers diving lights. They feed on fish and crustacean species and are fast voracious feeders. Females tend to congregate in shallow waters at night to lay clusters of white egg capsules which they attach to the sea floor, with 2 to 6 eggs per capsule. Juveniles grow rapidly, reaching maturing at a mantle length of 16 centimetres and an age of one year, they grow to a maximum length of 50 centimetres.
The southern calamari are a popular species, and are readily caught by both commercial and recreational fishers. They are a temperate water species that can be found around the southern coastline of Australia, from Dampier, WA to southern Queensland.
Other common names include: calamari, calamary, grass squid, squid
Occurrence at the Busselton Jetty:
The southern calamari can occasionally be observed from the underwater observatory in the open water zone, dispersed amongst the jetty piles. Their transparent bodies make them difficult to be seen as they hover and move with the flow and ebb of the water currents. They are extremely abundant in the waters surrounding the Busselton Jetty, the sand and seagrass habitats provide perfect shelter for all cohorts. The ink stains atop the jetty are an indication of this.
Image by: O. Rynvis