Nurse Shark Shark Bites

My name's Steve Backshall.

Self-confessed shark obsessed.

This is Shark Bites.

This time, we meet the supersucker of all sharks - the nurse shark.

These are experts at shelling seafood

and have evolved vacuum suction for dealing with their dinner.

Reaching up to three metres, they're found in tropical reefs where

there's plenty of prey wandering the sea floor.

Unlike most sharks, they have a taste for spiny lobsters, crabs

and even conch, but crustaceans and shellfish come heavily armoured.

So how does the nurse shark prise out its prey?

Mexico's coast provides the perfect place to find these sharks.

Well, this is really impressive.

Exactly what you'd hope for from a Caribbean reef.

And the perfect habitat for our shark.

Just sleeping underneath this overhang here is a nurse shark.

These sharks have small holes behind their eyes called spiracles that

they can breathe through, which enables them to lie like this,

just chilling out in the daytime.

At night, though, they go out on the reef to hunt.

Looking at the front of the nose,

there are two sensory barbels that hang down.

They use those to taste crustaceans and other animals that are

down in the sand on the seabed, and it uses those to sense its prey.

But when it comes to eating,

it also has to overcome some highly fortified food.

The nurse shark has an ingenious solution for shelling

its seafood supper.

Inside the shark's head, its mouth is actually quite small,

but this area to the back of the pharynx is really large.

So by cupping its mouth over a hole or crevice or seashell

and then expanding its throat,

it creates vacuum suction which can suck out its prey.

And all of that happens in about a tenth of a second -

that's as fast as the blink of a human eye.

Having found its dinner, it latches on, so there's no escape,

and hoovers up its prey like an aquatic vacuum cleaner.

The nurse shark.

Armed with specialist prey detectors,

it's an expert at shelling seafood and sucks it down in the blink

of an eye, making this an exceptional supersucker.