by Nicole Webster
Autotomy is a common defense mechanism for many animals; leave a small part behind to distract your predator, while your important parts escape to play again another day.
Two well known marine examples are many crustaceans and echinoderms (not exactly a small subset, hey?), both groups that have excellent regenerative powers (crustaceans at each moult, and echinoderms, well… because they’re made of magic*). A recent paper has shown this feature in a new group: squids. It was known already that octopuses can also autotomize, but my favorite part of this article is that the squid will actually counter-attack it’s predator (or bottle-brush, see video), attaching the arm before dropping it and jettisoning to safety. Not only does the dropped limb grasp its attacker and wiggle distractingly, it also glows!
*No, not actually, but they are amazing!