These glow-in-the-dark squids hunt in groups, and their collective foraging has been described by the scientists as a "feeding frenzy". The new research and ROV footage suggest that Humboldt squids communicate with each other as they hunt and socialize. They do so as they change patterns of light and dark pigmentation that can be seen in pitch-black deep ocean because the squids glow in the dark, according to MBARI.
Packed with numerous small bioluminescent organs called photophores embedded subcutaneously throughout the muscle tissues that make them glow, Humboldt squids use this "backlighting" to "boost the contrast" for its skin pattern changes, Stanford University news report.
Humboldt Squids' Telecommunication Device
Study collaborator Ben Burford, in Stanford report that the patterns made by squids might be because they need it to facilitate group behavior, thus increasing their chance of survival. Squids that live in the shallow parts of the water don't have these light-producing organs, it is possible that this behavior could be a product of evolutionary innovation from living in the dark open ocean.
Burford realized that when interacting with one another in groups, Humboldt squids exhibit specific color patterns. Keeping in track the behaviors of 30 Humboldt squids while they were swimming alone or in groups led him to this realization.
The color changes in the squids' skin are their way to communicate with one another. MBARI explains that when squids are feeding and displays a half-light/half-dark pattern it could be a warning, like: "Look out - I'm going to grab that lanternfish!"
Stanford report notes that the squids can move with exceptional precision, never colliding with each other. This behavior suggests that their pigmentation changes may be effective means of communication, just like how humans use turn signals in traffic, MBARI said.
Experts also found out that the Humboldt squids use patterns in specific sequences similar to humans arranging words in a sentence. In squid talk, one sequence of patterns could mean "Look out! I'm going to grab that lanternfish," but a different sequence could mean "Look out! Or I'm going to eat you!" explains MBARI.
In conclusion, the oceans that are Earth's largest habitat and the least known offers more room for discoveries in natural history and animal behavior- just how scientists discovered the amazing way squids deep in the ocean communicate.
