Giant squid a single global species

A new study comparing the DNA of a giant squid held at Te Papa with samples from 42 of its relatives from around the globe has revealed that mysterious sea creatures comprise a single, yet extremely spread out, species.

Giant Squid encased in ice at Melbourne Aquarium. Credit: FlagStaffFotos
Giant Squid encased in ice at Melbourne Aquarium. Credit: FlagStaffFotos

Very little is known about the enigmatic giant squid, with most of our knowledge gleaned from partial or whole dead squid washed up on beaches or found in the stomach of whales. It was only last year that the first video footage of a giant squid in its natural habitat was captured.

Now, an international team of researchers has determined that all giant squid are members of the same species, Architeuthis dux, refuting previous arguments that there were more than 20 different species in the giant squid family. The findings were published in Proceedings of the Royal Society B this week.

In the new study, researchers analysed total of 43 samples from individual squid from around the worlds oceans (15 of which came from New Zealand waters) and found that giant squid from all over the globe were remarkably genetically similar, representing one – very spread out – breeding population.  The researchers found no substantial genetic differences between samples from regions as far apart as Florida and Japan.

The authors suggest that the global giant squid population may so similar due to young larval squid drifting throughout the worlds oceans currents. The widespread nature of their travels means no geographically distinct populations have become established.

They also note that this planet-wide interbreeding, or panmictic, population is unique among studied marine organisms.

Examples of national and international coverage include: Giant Squid All One Species
TVNZ News: Giant squid mystery may have been cracked
MSN NZ News: Scientists dive into monster’s gene pool
Wired: Giant squid are single species
Science Daily: Enigmatic giant squid is same species in all oceans of the planet
Science News: Giant squid population is one big happy species
Australian Geographic: Giant squid: only one species on Earth
BBC News: Science In Action, Giant squid secrets revealed
Popular Science: Despite Widely Varied Appearances, Giant Squid Worldwide Are Only One “Very Weird” Species
Scientific American: Giant Squid Reality: There Were Once Few Kraken