What is a blue ringed octopus classified as?

Blue ringed octopus is the common name for the genus Hapalochlaena, which contains three species:

*Greater Blue-ringed octopus (Hapalochlaena lunulata)

*Southern Blue-ringed octopus, also known as the Lesser Blue-ringed octopus (Hapalochlaena maculosa)

*Blue-lined octopus (Hapalachlaena fasciata)

Based on one description given of a single specimen in 1938, some think that there may be a fourth species, Hapolachlaena nierstraszi, but that is uncertain.