Watch an Expert Diver Deflect the Attacks of Aggressive Tiger Sharks and Stand One Up Vertically

Did you know that tiger sharks are excellent at headstands? Below, we share a clip that proves it. The huge fish is given a bit of help by a human diver which is something you may not want to try yourself! He gently puts his hand on the tip of the shark’s nose and eases it into an upright position. Once in a headstand, the shark freezes. This is a phenomenon called tonic immobility and it doesn’t just happen to sharks. As the clip at the bottom of this page shows, it’s a very useful tool for scientists who need to handle these magnificent but potentially dangerous animals.

What Exactly Is Tonic Immobility in Tiger Sharks?

Tonic immobility is essentially a reflex. It puts animals into a state of complete inactivity which is very similar to hypnosis in humans. This state can be induced in many different species including sharks and rays. It can happen naturally but we can make it happen by stimulating the sensory pores on the end of a shark’s snout.

In this state, the shark is initially disorientated and then becomes deeply peaceful. Its muscles are relaxed and its breathing slows down. Some experts think that this is an ancient defense strategy because playing dead could put off some predators. Others think that it is related to mating, but the truth is that nobody knows why it happens.

Which Other Animals Experience Tonic Immobility?

Did you know that chickens can be put into a trance?  You can induce tonic immobility in chickens with some simple maneuvers. You put the chicken’s head on the ground and draw a line with a stick starting at their beak extending straight outwards. This seems to immobilize them, and they stay still for up to 30 minutes staring at the line!

A similar state can be induced in trout by ‘tickling’ them. This is a well-known poaching technique in many countries including the UK. If you rub the underbelly of the trout in the right way, they enter a trance-like state. This makes it a lot easier to pick them up and put them in your bag!

Can Tonic Immobility Be Harmful?

There is no evidence that it is harmful to tiger sharks. Rabbits can enter a state of tonic immobility when they are captured by a predator. They appear completely lifeless, and this can prompt the predator to release their grip because they think that the rabbit is already dead. This gives the rabbit a chance to escape.

If you tip your bunny onto its back it is possible to induce this state. However, their heartbeat is increased and they have higher levels of stress hormones – you should therefore avoid it.

Watch the Extraordinary Tiger Sharks Footage Below