Deep-Sea Squid Mom with Giant Eggs Captured by Scientists

Scientists at the Monterey Bay Aquarium Research Institute (MBARI) have released never-before-seen video of a deep-sea squid cradling dozens of exceptionally large eggs. Captured at a depth of 8,419 feet (2,566 meters) by the institute’s advanced underwater robot Doc Ricketts during an expedition to Mexico’s Gulf of California way back in 2015, the video has emerged after a team of researchers from MBARI, GEOMAR’s Helmholtz Centre for Ocean Research Kiel, and the University of South Florida conducted a “meticulous review of the ROV footage and examined specimens of similar-looking squid collected on previous expeditions to the Gulf of California.”

While MBARI researchers have previously observed deep-sea squids brooding their eggs, this particular sighting is highly unusual because the eggs are twice as large as those of other brooding deep-sea squids. It’s also remarkable because deep-sea squid typically produce thousands of tiny eggs—as many as 3,000 at a time—but this footage shows the mother squid clutching a cluster of only about 30 to 40 eggs. Each egg is approximately 11.6 millimeters, or about a half inch, in diameter—that’s roughly twice the size of eggs from previously sighted brooding Gonatus squid, which are no bigger than about 6mm, or about a quarter of an inch.

So, why so few large eggs? As the deep sea offers more stable and predictable conditions, devoting energy to producing a small number of giant eggs may be more beneficial since they have a good chance of survival, as opposed to environments with limited food and/or high predation, where it is more beneficial to produce a huge quantity of small eggs. This theory is supported by previous sightings of other deep-sea cephalopods, such as the warty deep-sea octopus and the pearl octopus, both of which have been observed with atypically small broods of large eggs.

“The deep sea is the largest living space on Earth and there is a lot left to be discovered,” says MBARI Senior Scientist Steven Haddock, chief scientist during the expedition that encountered the brooding cephalopod. “Our unexpected encounter with a squid brooding giant eggs caught the attention of everyone in the ship’s control room. This remarkable sighting underscores the diversity of ways that animals adapt to the unique challenges of living in the deep.”

The exceptional rarity of the footage is highlighted by the statistics surrounding MBARI’s exploratory efforts: Just 17 squid mothers cradling their eggs have been caught on camera over 37 years of exploration.

Check out the video below and find out more about MBARI’s work here. You can also read the short scientific paper detailing the discovery on the website of the journal Ecology.