Blue-lined octopus

Blue-lined octopus
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Order:	Octopoda
Family:	Octopodidae
Genus:	Hapalochlaena
Species:	H. fasciata
Binomial name
Hapalochlaena fasciata (Hoyle, 1886)
Synonyms[1]
Octopus fasciatus (Hoyle, 1886) Octopus pictus subsp. fasciata Hoyle, 1886-01 Octopus pictus var. fasciata Hoyle, 1886 Octopus robustus Brock, 1887

The blue-lined octopus (Hapalochlaena fasciata) is one of four species^[2] of highly venomous blue-ringed octopuses. It can be found in Pacific Ocean waters that stretch all the way from Australia to Japan.^[2] It is most commonly found around intertidal rocky shores and coastal waters to a depth of 15 metres (49 ft) between southern Queensland and southern New South Wales. It is relatively small, with a mantle up to 45 millimetres (1.8 in) in length. In its relaxed state, it is a mottled yellow-brown with dark blue or black streaks covering the whole body apart from the underside of its arms, but its vibrant blue markings appear as a warning to predators when they feel threatened.^[3] Along with its other closely related species, the blue-lined octopus is regarded as one of the most dangerous animals in the sea, and its venom can be fatal to humans.^[2]

Behavior[]

Blue-lined octopuses tend to swim around shallow areas of coral reefs and tide pools.^[4] They often hide in crevices of reefs, empty seashells, and other ocean resources they can find to conceal their identity.^[4] They are diurnal creatures, hunting crabs and small fishes during the day.^[4] They do not use their venom (known as tetrodotoxin) to kill their prey, but instead trap it inside their arms and pierce them with its parrot-like beak.^[4]

Lethality[]

Blue-lined octopuses can be very lethal to humans. Their saliva contain a special neurotoxin called tetrodotoxin.^[5] However, the species is more likely to flee and find shelter in an encounter due to their extremely shy in nature.^[3] Nonetheless, there have been at least three reported human deaths from the blue-lined octopus.^[6] It poses most danger to those who pick up the octopus and physically touch it.^[3]

If a human is to be attacked by the octopus, the injection may not be felt at first due to the small injection apparatus of the octopus.^[3] After some time, symptoms of the injection include loss of feeling in the tongue/lips, muscle weakness/paralyzation, respiratory failure, unconsciousness, and eventually death.^[3] The tetrodotoxin in blue lined octopuses is so lethal that it has been estimated that the venom from a single 25 gram octopus can kill about ten 75 kilogram humans.^[5]

Reproduction[]

The blue-lined octopuses start reproducing at a year old.^[4] Males seek out female companions and then pounce on them. If they are successful, the female octopus will lay 50 to 100 eggs 30 days after the encounter.^[4] During the 30 days, the female octopus hide her eggs under her arms and does not leave her hiding spot until the eggs hatch.^[4] After laying her eggs, the female octopus dies.^[4]

References[]