Watch a squid disconnect its arm to survive attack

Squids are the double-0-sevens of marine life, equipped with surprising survival gadgets that make them slippery and formidable. When in trouble, a squid can camouflage themselves, flush out a pool of ink creating a dark cloud for them to escape by, or turn on light-emitting organs on the tips of their arms to distract predators or prey. And now, Aquatic researcher Stephanie Bush has discovered a type of squid, the O. deletron, that can detach parts of its arm to help with fighting.

Called arm autotomy, this survival tactic only works when the squid’s arm is under tension, “either by grabbing and holding on to something, or by something grabbing it by one or more of its arms,” writes Phys.org.

Bush also brought some specimens into the lab and found that when provoked, seven out of eleven of them broke off arm parts. She also noted that not only were the squid able to let go of arm parts, similar to the way lizards let go of tail parts, but that they did so at the point on their arm that was closest to the object being attacked, thus minimizing tissue loss.

Bush published her findings in a paper for the Marine Ecology Progress Series.