The deeper you go, the stranger they come. In the dark depths of Alaska, ocean explorers stumbled across an unusual species of cockatoo squid (Cranchiidae) with a see-through body, illuminated organs, and a lightly waving tail that gently propels it through the water.
As part of the Gulf of Alaska Seamounts 2019 expedition from July 21 to August 3, a team of scientists and media personnel onboard the R/V Sikuliaq explored the Gulf of Alaska Seamounts region. Over the course of 11 remotely operated vehicle (ROV) dives, they gathered dozens of hours of footage documenting the murky depths and its inhabitants.
The cockatoo squid was filmed by the NOAA’s Global Explorer ROV at a depth of 527 meters (1,729 feet). Among the many species they encountered – from octopus and fish to sea cucumbers and jellyfish (images below) – this guy remained a standout favorite for the researchers.
“Some of the animals we have seen on the seafloor and in the water column are just amazing, but the best was this: we were following a Cockatoo squid (Cranchiidae), just filming it and watching when all of a sudden it turned its head to the ROV like it was acknowledging we were there and briefly stared at us before turning away,” Travis Kolbe, ROV superintendent on the expedition, wrote in a blog post. “We all laughed because it was just THAT AMAZING to see one of these animals behave that way. Just simply incredible is the only way to describe it.”
Cranchiidae is a family of squid that's made up of over 60 species of glass squid. In order to remain hidden from predators and prey, their whole body is often transparent except for the eyes and organs. Although born as paralarvae near to surface waters, they are believed to migrate to progressively deeper waters as they grow larger.
One of the mission's objectives was to compare the creatures that lived on the seafloor of the continental slope to those at the base of a seamount at a similar depth. Seamounts are underwater mountains that rise hundreds or thousands of feet from the seafloor. They are quite often the product of extinct volcanoes and, as such, are most common near the boundaries of Earth’s tectonic plates.
They are also considered “oases of life”. Since they provide deep-sea creatures a surface to settle on and grow, they tend to harbor a considerably higher species diversity than the waters around it. Some species are even believed to be endemic to just a single seamount. Despite their importance to biodiversity, it’s estimated around 0.1 percent of the world’s seamounts have been explored.