This is 6 Minute English

from BBC Learning English.

I'm Sam.

And I'm Rob.

Now, on Friday

the 29th of June 1975,

movie posters appeared in

cinemas all over the

USA with the now

notorious words: 'You'll

never go in the water

again'.

So, do you know

which movie was being

promoted, Sam?

Yes, I think it was

'Jaws' - Steven Spielberg's

infamous horror movie

which terrified a

generation with its

story of a man-eating

great white shark with

a taste for revenge

and for human flesh.

Jaws multiplied people's

fascination with, and

fear of, sharks.

But sharks' fearsome

reputation is not based

on facts: most attacks

on humans are cases

of mistaken identity,

where the shark mistakes

a swimmer for fish.

In recent years the

average annual number

of worldwide deaths

from shark bites was

as low as four.

Today sharks should

be the apex predators

of the ocean - the top

predator that hunts

and eats other animals

but has no natural

predator of its own.

Instead, over 100 million

sharks are caught and

killed each year and,

thanks to this overfishing,

many shark species are

now endangered.

We'll

hear more soon, but

first I have a question

for you, Rob.

Approximately, how many

different species of

shark exist today?

Is it: a) 330?

b) 530?

or

c) 730?

Well, I'll take a

guess at b) 530.

OK, I'll reveal the

correct answer later

in the programme.

Now, as Sam mentioned,

'Jaws' made many people

nervous about swimming

in the sea, largely

thanks to scenes in the

movie showing the shark

biting swimmers in a

frenzy of teeth

and blood.

George Burgess has spent

40 years studying the

cause of shark attacks

in his job as director

of the Florida Programme

for Shark Research.

According to him, the

movie's depiction of

great whites is totally

unrealistic, as he told

BBC World Service

programme, The Inquiry.

Will a single shark that's

involved in a bite on a

human be more likely to

bite another human in

the future?

In other

words, is there

something of the 'Jaws'

image as we saw,

unfortunately, in the

movies of which you

had a white shark that,

apparently, had a

grudge and would

try to go after

humans...

well,

nothing could be

further from the truth

than that.

In the movie, sharks

are portrayed as vengeful

creatures who recognise

and try to kill

individual people.

The shark in 'Jaws' had

a grudge - a feeling

of anger or hatred

towards someone because

of what they did

in the past.

According to marine

biologist, George Burgess,

this is nothing like

the real behaviour of

sharks in the wild.

He

says nothing could be

further from the

truth - an expression

used to emphasise that

something is not

true at all.

The actual truth is that

sharks have been

perfectly designed by

evolution for their

ocean environment.

In fact, they have

hardly changed over

the last 400 million

years, making them

even older than

the dinosaurs.

Sharks' characteristic

design - their fin,

teeth and skin - allows

them to thrive in their

natural environment.

Listen to Oliver Crimmin,

senior curator at London's

Natural History Museum,

explaining more to BBC

World Service programme,

The Inquiry.

If we look at the really

successful features of

sharks you've got to

consider this

cartilaginous skeleton -

that's no bone in the

skeleton.

That flexible

material that the

skeleton is made of

enables sharks to be

very agile, and it

enables them to be

athletic and

it's lightweight.

Sharks' skeletons are

made of cartilage, not bone.

Cartilage is a strong

flexible tissue which

connects joints in the

bodies of living creatures.

Feel for the bony material

in the fold of your

ear - that's cartilage.

Not having bones allows

sharks to be both

flexible - able to bend

without breaking, and

agile - able to move

their body quickly and

easily.

Boneless, bendy,

and built for speed,

sharks really are the

perfect evolutionary design.

Yet overfishing and

the cruel practice of

finning, cutting off

shark fins to make

exotic soups and

returning the wounded

creature to the sea

to die, are threatening

shark numbers.

Which is why it's tragic

that so many of their

species are facing

extinction.

And

speaking of shark

species, what was

the answer to your

question, Sam?

In my quiz question,

I asked how many species

of shark there are

in existence.

Yeah, and I guessed

it was around 530

different species.

Which was the correct

answer, Rob!

And the

variety of shark

species is incredible,

from giants like the

great white to the

tiny dwarf lantern shark.

Ok, let's recap the

vocabulary from this

programme all about

sharks, the ocean's apex

predator - that's the

top predator that hunts

other animals but has

no predators

of its own.

If you hold a grudge,

you have feelings of

anger towards

someone because of

something they did

in the past.

The phrase, nothing

could be further from

the truth, is used

to emphasise that

something is totally false.

Cartilage is the

strong flexible tissue

connecting bones or

joints in the body.

Flexible means able

to bend without breaking.

And finally, if you're

agile, you can move

your body quickly

and easily.

Once again, our

six minutes are over.

Bye for now!

Goodbye!