The blue-lined octopus (Hapalochlaena fasciata) is one of three (or perhaps four) species of highly venomous Blue-ringed octopuses. 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...