The Southern Blue – ringed octopus Haplochalena maculosa is a resident along the southern coastlines of Australia where it is quite common.
Growing to around 15 cm (5 in), the Southern Blue-ringed Octopus is not an aggressive species.
Generally it will make every effort to conceal itself. When the Octopus gets disturbed and threatened, it will immediately turn into a darker colour with fine light blue circles that expand and glow like pulsating blue neon.
They say that you never feel the bullet that kills you, and in the case of the Blue-ringed Octopus this is equally applicable. Although the venom is one of the most potent biological toxins known, the bite has yet to be felt. There have been several fatalities known from other species of Blue-ringed octopus and a number of bites recorded where those bitten have survived due to early resuscitation.
Death results from the extremely potent neurotoxins manufactured by the saliva glands that block the passage of sodium ions into the central nerve region. Thus, when the nerve impulses are blocked and the respiratory muscles paralysed, the resulting anoxia, or asphyxiation can be fatal.
The beak is on the underside at the centre of the animal’s eight-armed web. It is very small and the amount of toxin present is minuscule, yet there is enough in one bite to kill between 10 to 25 people.
Injuries and deaths have resulted when various species of these small octopuses have been picked up to show off their bright pulsating blue rings. Venom is introduced to the body by way of a bite break in the skin.
The venom produced by the salivary glands is comprised of two highly toxic substances, maculotoxin which has similar properties as tetrodotoxin (Pufferfish poison) and hapalotoxin.
The former is deadly to vertebrates and the latter deadly to invertebrates (crustaceans) upon which these small octopus feed.
However, both appear to block transmission impulses between nerves and muscles in humans.
Injuries and deaths have resulted when various species of these small octopuses have been picked up to show off their bright pulsating blue rings.
Venom is introduced to the body by way of a bite break in the skin.
Be extra careful with any small Octopus encountered during bait collecting, shelling, fishing, netting, trap hauling, prawning, or trawling, especially ones with blue rings or `startle’ patterns, as many small Octopus besides Blue-ringed Octopus also have toxic venom apparatus.
Bite is rarely felt or recognised and in many cases could not be found.
Speech is affected with noticeable slurring and numbness, or "thick" feelings around neck and mouth.
Nausea and possible vomiting.
Vision may become blurred, with breathing difficulties and coordination degenerating to respiratory paralysis.
Duration of paralysis may extend from four to 12 hours with casualty feeling totally drained of energy for sometime after recovery.
FIRST AID MANAGEMENT:
- Reassure the casualty
Wash area of bite or where the octopus was sitting
Apply the pressure immobilisation technique
Resuscitation may be required
Give continual reassurance as paralysed casualties can still hear and are conscious throughout the ordeal, even though they are unable to respond
Seek Emergency Service Assistance