Taningia danae

Taningia danae, the Dana octopus squid, is a species of squid in the family Octopoteuthidae. It is one of the largest known squid species, reaching a mantle length of 1.7 m and total length of 2.3 m. The largest known specimen, a mature female, weighed 161.4 kg.

Taningia danae is named after Danish fisheries biologist Åge Vedel Tåning (1890–1958), who often traveled on the research vessel Dana.

Ecology
Taningia danae possesses bioluminescence, like other octopoteuthids. Its photophores are some of the largest such organs known to science, the organs being compared in size to fists or lemons. They possess a black membrane over the photophore that may conceal the organs, allowing the squid to blink its lights; this membrane has been compared to eyelids as a result.

In 2005, a Japanese research team headed by Tsunemi Kubodera managed to film T. danae in its natural habitat for the first time. The video footage, shot in deep water off Chichi-jima in the northern Pacific Ocean, shows T. danae emitting blinding flashes of light from photophores on its arms as it attacks its prey. It is believed that this highly maneuverable squid uses the bright flashes to disorient potential prey, as well as to illuminate the prey to make for easier capture in a dark environment. These flashes may also serve a role in courtship and territorial display.

As well as a predatorial characteristic, T. danae bioluminescence has also been suggested to be a defense mechanism. Juveniles of this species have been observed moving rapidly in the direction of potential predators, as if hunting, to disorient and startle the threat with a mock attack.

In 2012, T. danae was filmed twice more during a search for the giant squid for the Discovery Channel Special, Monster Squid: The Giant Is Real.



Remains of T. danae have, on occasion, been found washed ashore on beaches. In 2008, a mantle of T. danae was discovered by students in Bermuda's Grape Bay, while tentacle remnants were found farther along the shore. In early 2013, a 54 kg specimen with a length (excluding arms) of 103 cm was trawled at a depth of 240 m off the coast of Estaca de Bares, Galicia, Spain. It was loaned to the Spanish Institute of Oceanography.

15N ratios showed that this squid is a top predator. In turn, they are eaten by the sperm whale.