[LINK] "Watch Jumbo Squid Speak by 'Flashing' Each Other"

[rfmcdonald]

National Geographic's Jane J. Lee describes what we are learning about the communications methods of Humboldt squid. (Video is at the site.)

Giant Humboldt squid, which can grow as big as a man, speak to each other in flashes of color, their whole bodies quickly changing from red to white and back again. But just what they’re communicating has long been a mystery to scientists.

[. . .]

The new research is the first to track communications between free-swimming Humboldt squid, partly because the animals show no fear of human divers. They’ve been known to rip off a diver’s mask and to attack lighting and camera equipment. The predators sport suckers lined with sharp teeth, have a two-inch-long beak used to sever the spines of fish, and have no qualms about ripping apart and eating injured comrades.

Scientists mounted cameras on three of the animals—a first for squid research—and are using the footage to begin deciphering the chatter of flashes and flickers used by these five- to six-foot-long (1.5- to 1.8-meter) “red devils.” The new study is published Wednesday in the Journal of Experimental Biology.

One of the Humboldt squid’s more “attention-grabbing behaviors” is rapidly flashing nearly its entire body from red to white to red again, says Hannah Rosen, a doctoral student at Stanford’s Hopkins Marine Station in Pacific Grove, California. Actual light, like bioluminescence, isn’t involved.

It’s probably an attempt to communicate, she says, based on National Geographic Crittercam video first taken in 2009 that shows most squid flash only in the presence of other squid.

The animals can speed up or slow down their flashes to send different messages. But researchers have no idea what the squid are trying to say—maybe they’re broadcasting come-ons to prospective mates, or throwing down with potential rivals. “That is the question of the hour,” says Rosen, the lead study author.