Crittercams attached to giant squid reveal that the marine creatures flash colorful lights to communicate and attract mates.

Scientists at Stanford University's Hopkins Marine Station mounted cameras, known as Crittercams, on three giant Humboldt squid. Even after mounting the camera, the squid were able to freely move their tentacles and fins. The main purpose of putting the camera on the giant squid was to understand some underwater behavioral aspects of the marine creatures.

Experts have known that squid flash red and white colors to communicate with each other. Hannah Rosen, lead author of the study, says that the squid send different messages by speeding up or slowing their flashes. They may be communicating to attract mates or send warning signals to rivals. However, what they are communicating still remains a mystery.

"That is the question of the hour," said Rosen.

The Humboldt squid is one of the biggest squid species known. A full-grown Humboldt squid can reach 1.5 meters, or 4.9 feet. It is known for its aggressive behavior toward divers. This giant squid is mainly found off the coast of Chile and can also be found as far north as Alaska.

The creature usually spends most of its life in the mid-water region. Unlike the octopus, which can camouflage skin color to match surrounding rock or algae, the giant squid usually mimics sunlight patterns on its body, which confuses nearby predators.

The study authors are not sure about the sex of the squid on which the crittercams were mounted, but they assume that they were female. The video footage shows the squid splaying their arms, but the move is not related to mating.

"In one case, a pair of secondary squid were interacting and as the primary squid approached, they both turned to face the oncoming squid and opened their arms as far as possible for several seconds and then jetted backward, away from the camera," reported the researchers.

Scientists hope to redesign the mounted camera on the squid to get even better underwater video of the squid. The researchers aim to attach more crittercams to giant squid in the future to better understand their aggressive behavior.

The study is detailed in the Journal of Experimental Biology. The giant squid crittercarm videos are available at the Supplemental Materials page of the study[PDF]