So, you’ve been down the lake all day trying catch something for your dinner. You finally manage to reel a fish in, which you stun and throw in your cool box. You get home, cut the fish’s head off and take its guts out. It’s dead, right? Of course it is! It’s been brained and has sat in an ice box for an hour. Man, it doesn’t even have any guts. Or a head!
So why is this fish still moving?! Sat on the work surface, headless and supposedly dead, the little fella starts squirming all over the place. What gives? It surely can’t still be alive. Perhaps it’s a zombie fish? Or perhaps its soul is yet to escape?
Well, no. There’s actually a very straightforward explanation. Simply put, even without a functioning brain or heart, there are cells in the fish’s body which are still reacting to stimuli. After death, motor neurons maintain some membrane potential, or a difference in ion charge, which then starts a domino effect down neural pathways causing movement. This is phenomenon is not just restricted to fish. Indeed, even humans have been known to randomly move after death.
Watch the video below.