Giant Squid

Architeuthis dux

Giant Squid (Architeuthis dux) is a species in the genus Architeuthis, family Architeuthidae, order Oegopsida.

Scientific classification

Description

The giant squid is among the largest invertebrates, with females reaching perhaps 13 metres including the two long feeding tentacles; the mantle itself is a far more modest two metres or so. Much of the popular size record consists of stretched tentacles measured from decaying specimens.

The eye is the largest known in the animal kingdom, up to about 27 centimetres across. The leading explanation is not general low-light vision but the specific problem of detecting the bioluminescent glow triggered by an approaching sperm whale, at ranges where a smaller eye would fail.

Discovery

For most of scientific history the animal was known only from carcasses, stomach contents of sperm whales, and sucker scars. It was not photographed alive in its habitat until 2004, and not filmed until 2012 — both by Japanese teams working at depth off the Ogasawara Islands.

Biology

Architeuthis lives in the deep ocean, roughly 300–1,000 metres, and appears to be a solitary ambush predator taking fish and other squid with the toothed suckers of its feeding tentacles. Genetic work published in 2013 found strikingly low diversity across specimens from all oceans, consistent with a single global population and, possibly, a recent bottleneck.

Cultural note

The giant squid is the most plausible origin of the kraken of Nordic seafaring accounts, though the literary kraken is far larger and far more aggressive than the animal.

References

• Winkelmann, I. et al. (2013). Mitochondrial genome diversity in Architeuthis. *Proceedings of the

Royal Society B* 280.

• Nilsson, D.-E. et al. (2012). A unique advantage for giant eyes in giant squid. Current Biology 22.