The cephalopods (meaning 'head-footed'), a group of molluscs that contain the octopuses, squid and cuttlefish, are probably the most intelligent of all invertebrates. They have well-developed heads, with large eyes and mouths that feature beak-like jaws. All octopuses have eight tentacle-like arms; indeed 'octopus' derives from the Greek for 'eight-footed' (5). The curled octopus is typically yellowish or reddish-orange in colour with rusty-brown patches and a whitish underside; individuals are able to rapidly change colour to suit their surroundings (3). The slender arms taper towards the tips; they feature a single row of suckers and are curled when the octopus is at rest, hence the common name (3).
Like all cephalopods, the curled octopus is an active predator (4). It usually feeds on crustaceans, molluscs and other invertebrates as well as fish (4). When feeding on crabs, the curled octopus immobilises its prey by puncturing its eye and injecting toxins into the body of the crab. The digestive enzymes contained in the saliva of the octopus break down the attachments within the crab's body, allowing the carapace to be easily removed (4).
Wilson, A., 1999. Eledone cirrhosa. Curled octopus. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. (November, 2002) http://www.marlin.ac.uk/species/Eledonecirrhosa.htm
Buczacki, S. (2002) Fauna Britannica. Hamlyn, London.
Grisley, M.S., Boyle, P.R. and Key, L.N. (1996) Eye puncture as a route of entry for saliva during predation on crabs by the octopus Eledone cirrhosa (Lamarck). Journal of Experimental Marine Biology and Ecology, 202: 225 - 237.
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