Scientists Still Don't Know Why Sharks 'Freeze' when Turned Upside Down

Scientists still don't know why sharks 'freeze' when turned upside down

Sharks freeze when turned upside down, but not every shark does it, and scientists can't figure out why this is the case.

Sharks Do Something Strange When Upside-Down, and Scientists Aren’t Sure Why

Flip certain sharks upside down, and they’ll suddenly go limp. Their bodies slacken, their fins stop moving, and for a moment, it’s like they’ve completely checked out. It looks like they’re faking death. But scientists still don’t know what they’re doing or why it happens. The reaction is called tonic immobility, and it’s not unique to sharks. Possums do it. So do rabbits, snakes, and even insects. But a new study published in Reviews in Fish B…