It was a normal day above the ocean, but scientists would soon realize that after sending an observation sub up to 2,000 meters below the ocean surface, things can get pretty freaky.
One of the things they found were giant squid from the Gonatus Onyx species family devouring one another in an act of cannibalism, and surprisingly, they didn't spot it just once.
Image Credit: 2010 MBARI
Cannibalistic behavior has already been known to exist in giant squid species, but we only know that because of stomach content samples from deceased specimens and sightings of a phenomenon known as net feeding, which is where one species may be eating another of its own kind while trapped in a fishing net due to stress.
“Animals get stressed in a net,” Researcher Henk-Jan Hoving says. “They probably start doing something called ‘net feeding’ – they feed on anything that is close by.”
For the first time however, this research allowed scientists to observe the behavior up close in the species’ natural habitat and determine whether or not it was natural behavior. The findings have been published in the journal Deep Sea Research Part 1: Oceanographic Research Papers.
The conclusive evidence suggests it probably is natural. They saw many Gonatus Onyx’s deep below the surface, and the team reports that up to 40% of the observed specimens were participating in cannibalism, which is thought to be a rather high percentage for any animal.
Hoving was surprised to learn that due to this high percentage, partaking in cannibalism is probably normal behavior for the Gonatus Onyx. The conclusion was drawn from the fact that such a high number were partaking in it in their natural habitat with no known stress triggers.
Obviously, they can’t be eating each other all too often, because if eating themselves was all they did, then they wouldn’t exist anymore. Eventually, they'd eat their way to extinction. One thing they’ve got going for them is they’re very quick reproducers and they grow quickly.
The study chalks it up to the fact that giant squid will eat almost anything in reach. After all, once you get to a certain depth in the ocean, eating becomes a little harder to do as the population becomes a little more scarce.
Source: New Scientist