New Zealand and southern Australia from Perth to eastern Victoria and Tasmania (VIC, TAS, SA, WA).Features:
A large muscular octopus (Australia's largest) with an armspan that reaches over three metres. The body is oval-shaped and the eyes are large. The arms are long and muscular, the front pair being the longest and broadest. They are around 4 to 6 times the body length, each with two rows of suckers. The webs are deep with the edges extending to the arm tips. The colour is dark orange-brown scattered with numerous small white spots. The skin is covered in scattered large fingers of skin forming a spiky appearance in some postures.Ecology/Way of Life:
This octopus lives on rocky reefs and beds of seagrasses or seaweeds to depths of over 100 metres. It forms lairs in crevices or burrows, recognised by the scatter of shells and crab parts around the entrance. Larger animals often sit within the mouth of the lair. Smaller animals are generally night active while larger animals can be active during both the day and night. It feeds on a wide range of prey including crabs, abalone, crayfish, mussels, fish and other octopuses. The deep webs can be flared to trap prey. Day-foraging animals are often accompanied by wrasses that grab any prey that escape the octopus' clutches.
Mating occurs by the male engulfing the female within his webs and inserting the modified third right arm into her gill cavity to place sperm packets in her oviducts. The females lay strings of small eggs, attaching them to hard surfaces such as in rock crevices. The young hatch as planktonic young that travel in ocean currents between Australia and New Zealand.Interaction with Humans/Threats:
This octopus is harvested in both targeted fisheries and as bycatch. It is used for human consumption (often pickled in the Greek style) and as bait. This species takes a heavy toll on lobster pot fisheries throughout its range, leaving the empty lobster shells in the pots. Some estimates suggest up to one third of the potential catch is lost to octopuses. In recent years escape hatches have been included in lobster pots to allow undersize lobsters to escape. These hatches also allow raiding octopuses to escape, preventing the lobster fishermen from catching as many of the culprits as with the old style pots.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. 320 pp.
Text, map and photograph by Mark Norman, Museum Victoria.Sponsorship welcomed:
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