Video: Diver 'hypnotises' shark


Editor's Picks
Features Post
What caused this snail die-off?
04 January 2022
Fishkeeping News Post
Nanochromis transvestitus
04 January 2022
Features Post
How do I feed these tricky gobies?
04 January 2022
Features Post
Should I add sand for my Rams?
04 January 2022
Features Post
How to set up your Christmas tank
20 December 2021

A 'shark whisperer' in the Bahamas balances a shark on the palm of his hand, after sending it to sleep.

The diver uses what's known as tonic immobility (TI) to induce a state of temporary paralysis in a shark.

The usual method used to induce TI in shark species such as Blacktip and Whitetip reef sharks, Lemon and Leopard sharks is to invert the animal. According to The Shark Trust the unnatural posture is thought to alter the shark's sensi-motor interchange with the environment, causing it to go limp. The shark usually enters a state of TI in under a minute and may remain immobile for up to 15 minutes.

Some shark species respond in a similar way when hands are placed either side of the nose in the area surrounding their eyes.

TI doesn't cause the shark any harm and is often used by experts when handling them in the field to prevent struggling and possible injury to the animal.

TI is known to occur in other animals, particularly when they are threatened by a predator, but experts are unclear as to why the shark - itself a top predator - would develop such a reflex.

In the video below you can see a diver, known only as Tom, with a shark he has placed in TI.


Why not take out a subscription to Practical Fishkeeping magazine? See our latest subscription offer.

Don't forget that PFK is now available to download on the iPad.