The remotely operated vehicle (ROV) Deep Discoverer, operated by the NOAA Office of Ocean Exploration and Research, has come across what is believed to be a previously undiscovered species of octopus at more than 4,000 metres of water off the northeast of Necker Island in the Hawaiian Archipelago.
The dive off the island, known as Mokumanamana in Hawaiian, was to collect geological samples but as the ROV was crossing a flat area of rock interspersed with sediment at 4,290 metres, it came across a little white “ghostlike” octopod sitting on a flat rock dusted with sediment.
The animal is unlike any published records and was the deepest observation ever for this type of cephalopod.
There are two distinct groups of deep-sea octopods – the cirrate, or finned, octopods characteried by fins on the sides of their bodies and fingerlike cirri associated with the suckers on their arms; and the incirrate octopods, with neither fins nor cirri, which are similar in appearance to common shallow-water octopuses.
The ghost octopod is a member of the second group, the incirrates, with suckers formed in one, rather than two, series on each arm.
The lack of pigment cells, called chromatophores, typical of most cephalopods, as well as the depth where it was found makes it a most unusual specimen. No incirrates have been found below 4,000 metres before.
“After seeing this observation, I contacted my colleagues Louise Allcock, currently on a British ship near Antarctica, and Uwe Piatkowski, from Germany, and they agreed that this is something unusual and is a depth record for the incirrate octopods,” Michael Vecchione of the NOAA National Marine Fisheries Service wrote on the mission log.
“We are now considering combining this observation with some other very deep incirrate observations by a German cruise in the eastern Pacific into a manuscript for publication in the scientific literature.”