Pacific Bigfin Squid, photo by Richard E. Young (from tolweb.org)

Rare and poorly understood, Bigfin Squid were first formally defined in the 1990’s (although a single damaged specimen discovered in 1907 —M. talismani—has been subsequently assigned to the genus). Species of Magnapinna are characterized by small heads, large eyes, and very large fins that extend well beyond the posterior tip of the mantle. Almost all specimens described to date have been paralarvae or juveniles, and the adult forms are officially unknown. However, on multiple occasions in recent years, ROV submersibles have captured footage of a previously unknown large squid that is suspected to be the adult form of Magnapinna. Also known as the Long-arm Squid, these mysterious cephalopods are unlike anything previously observed.

photo by NOAA (from Wikipedia)

Its arms and tentacles (which are of equal length) are held perpendicular to the body and then angle downward (sometimes at 90°) at strange “elbows.” The relative length of arms/tentacles to the body is greater than in any other known squid (15-20 times the mantle length), and the total length of the animal is estimated to be as much as 8 meters (~26 feet). The Long-arm Squid has been observed in the Gulf of Mexico, the Indian Ocean, waters off Ghana and Brazil, and, as seen here, Hawaii.