Giant Squid DNA Suggests They’re All the Same Giant Species
There are a lot of people in the world whose recognition skills take a drastic nosedive whenever they’re being asked to differentiate between people of a different race, leading to the “They all look alike,” stereotype. That’s exactly how I feel about giant squids (Architeuthis), and while it used to embarrass me in a variety of social situations each year, it turns out the problem wasn’t completely my own.
For a study in the journal Proceedings of the Royal Society B, an international group of researchers compiled 43 tissue samples of giant squids, from sources ranging from accidental captures to the stomachs of beached sperm whales. Using DNA sequencing, the team mapped out the giant squid’s genetics and found there’s a good chance only a single species of the creature exists. There also appears to be no population structure, which is rather unlike most of Earth’s animals.
Working with colleagues from the University of Copenhagen, as well as researchers from Australia, France, Ireland, Japan, and Portugal, the National History Museum of Denmark’s Professor M. Thomas P. Gilbert found very low genetic diversity, despite its global presence — minus Arctic and Antarctic waters. Gilbert suspects the larval stage of the squid possibly drifts with currents, finding the nearest dark spot in the oceans’ depths to secure its habitat.
“Things that live in one area eventually become different from things in other areas but [giant squid] are basically identical everywhere,” Gilbert told BBC Nature. “Instead of the adults and their young living in the same place, the young distribute to a completely new place on the Earth every time.”
It’s still unclear why those found near Japan are short and stubby as compared to the common long and thin appearance, and no one is really sure just yet why they’re all the same. Their adaptation to harsh environments and size could mean their population is larger than previously thought, and now theories of a population boom abound. It could have been a decrease in predators. (Who is fucking with this guy, seriously?) It could have been an increase in prey. It could have been the regular-sized-squid enlarger machines I have hidden around the world.
Somewhat coincidentally, this news comes less than two weeks after the 200th anniversary of the birth of Danish biologist Japetus Steenstrup, who was the first person to formally report on the creature. Since he also dabbled in genetics, that gives this double coincidence points.