Blue-lined octopus

Appearance

It is relatively small, with a mantle up to 45 millimetres 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 it feels threatened.

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. This benthic octopus is one of four members of the genus "Hapalochlaena", with the other species being the greater blue-ringed octopus," southern blue-ringed octopus," and the blue-ringed octopus ". The blue-lined octopus is the only species of the four to display lined iridescent blue marking, as opposed to circular iridescent blue marking that the three other species tend to exhibit.

Distribution

Blue-lined octopus are commonly found off the coast of Australia inhabiting shallow tropical and subtropical reef waters. However, in recent years they have been found to distribute throughout the Pacific Ocean. They have been recorded of the east coast of Japan, as well as off the coast of Jeju Island in Korea in 2015. This can suggest that the warming of ocean water has caused a shift in suitable habitat for these octopus, this shift is important to monitor as if can aid is public health and safety.

Behavior

Blue-lined octopuses tend to swim around shallow areas of coral reefs and tide pools. They often hide in crevices of reefs, empty seashells, and other ocean resources they can find to conceal their identity. Blue-lined octopuses are known to be nocturnal hunters, while other species in the genus such as the greater blue-ringed octopus " is known to be diurnal hunter. Prey for blue-lined octopuses mostly consists of crustaceans and stomatopods, however in captivity they have been recorded to eat live fish, suggesting they do in the wild as well. They do not use their venom to kill their prey, but instead trap it inside their arms and pierce them with its parrot-like beak.

Reproduction

The blue-lined octopuses start reproducing at a year old. During breeding male blue-lined octopus will seek and mount females, they do not extend the hectocotylus and mate from a distance like other octopus species. If they are successful, the female octopus will lay 50 to 100 eggs 30 days after the encounter. During the 30 days, the female octopus hides her eggs under her arms and does not leave her hiding spot until the eggs hatch. After laying her eggs, the female octopus dies. These eggs are large and produce benthic hatchlings, development for these hatchlings takes about two months.