Birds on the Brain

rhamphotheca:

Disarming Deep-Sea Tactics

by Amy Weston

Many deep-sea squid dispel an ink cloud to flee a predator, but one species goes a step farther: It ensures a getaway by counterattacking and then ditching the tips of its arms. These detached bits can continue to twitch and emit bioluminescent light—likely providing a vital distraction. By catching this strange maneuver on camera, scientists have established Octopoteuthis deletron as the only known squid to drop portions of its arms in self-defense, much as lizards drop their tails before escaping.

O. deletron inhabits depths of 500 to 600 meters. Little is known about the biology of these gelatinous deep-dwellers, but recently they have begun to yield their secrets—including some bizarre mating behavior—thanks to powerful video cameras mounted on robotic submersibles operated by researchers at Monterey Bay Aquarium Research Institute (MBARI) in Moss Landing, California.

Viewing some of this footage, Stephanie Bush, a postdoctoral fellow at the University of Rhode Island, Kingston, noticed many individuals with arms of different lengths, and suspected that these cephalopods lost their arms during an attack. To investigate, Bush collaborated with researchers at MBARI. With a bit of luck, the team found squid off the coast of California, and tried poking them with the control arm of the submersible…

(read more: Science NOW)       (photo: MBARI)