The Blue-Ringed Octopus

This species was mentioned in class, I had never heard of it before and found it quite fascinating. Here is some more on the Blue-Ringed Octopus.

The blue-ringed octopus is from the genus Hapalochlaena. They are actually three or four small octopus species living in tide pools in the Pacific Ocean, from Japan to Australia. The validity of one of the four taxons has been questioned since only a single specimen was found some time ago in the Bay of Bengal. The three are: the Greater and Southern blue-ringed and the Blue-lined octopuses.

The blue-ringed octupus is the size of a golf ball, but has a very powerful venom, one that can kill humans- for which there is no known antidote. The octopus produces venom that contains maculotoxin, 5-hydroxytryptamine, hyaluronidase, tyramine, histamine, tryptamine, octopamine, taurine, acetylchloline and dopamine.

An individual blue-ringed octopus will typically use its dermal chromatophore cells to camouflage itself until provoked. Then it will quickly change color, becoming bright yellow with blue rings or lines.

Their diet typically consists of small crab, and shrimp, but they may also feed on fish if they can catch them. They pounce on their prey, bite them then use their beaks to tear off bits. They then suck out the flesh from the crustacean's exoskeleton. They will hunt small crabs, hermit crabs, and shrimp but will bite an attacker (even humans) if provoked or stepped on.

When mating the male mates with a female by grabbing her mantle, which sometimes completely obscures the female's vision, then transferring sperm packets by inserting his hectocotylus into her mantle cavity over and over again. Mating continues until the female has had enough, and in at least one species has to remove the over-enthusiastic male by force.

Males will attempt copulation with members of their own species regardless of sex or size, however interactions between males are most often shorter in duration and end with the mounting octopus withdrawing the hectocotylus without packet insertion or struggle.
The blue-ringed octopus females will lay only one clutch of about fifty eggs in their lifetime towards the end of Autumn. Eggs are laid then incubated underneath the females arms for approximately six months, and during this process she will not eat. After the eggs hatch the female dies, and the new offspring will reach maturity and be able to mate by the next year.