Original subtitles

They've prowled earth's oceans and seas

For more than 400 million years

And survived five mass extinctions.

They might be the world's favorite real-life monsters,

But how monstrous are they, really?

♪ ♪

Renowned predators,

Sharks are also vulnerable prey...

♪ ♪

...With surprising sex lives.

However you look at sharks,

They're more complex than anyone gives them credit for.

♪ ♪

If we want to know all there is to know about sharks,

We're gonna need a bigger boat.

Elusive, captivating, and full of surprises.

For the very first time, sharks are spilling their secrets.

♪ ♪

♪ ♪

What's more private than sex?

At the heart of a south pacific atoll

In the shelter of a sleepy lagoon,

Two whitetip reef sharks find romance,

Or at least a shark version of it.

Sharks may be passionate, but they're not sentimental,

And mating can get kind of rough.

And this male is literally ready to bite.

But he's got competition.

While the first male clamps down on one of her fins

To get her attention,

His rival grabs the other.

The female can't escape this whirlwind romance.

These aren't just love bites; they can be deep and painful.

Fortunately, she has thick skin--

Twice as thick as the males'--

And it heals quickly.

Whitetip shark love isn't for the faint of heart.

♪ ♪

The ménage à trois doesn't last for long.

One of the suitors lets go,

And the pair descends to the ocean floor

To make baby sharks.

♪ ♪

♪ ♪

♪ ♪

The male inserts his reproductive organ,

His clasper, into the female's cloaca.

Male sharks are endowed with two claspers

But use only one at a time.

♪ ♪

♪ ♪

♪ ♪

♪ ♪

Despite all the foreplay, the mating takes only moments.

He inflates his siphon sac with seawater

To impregnate the female.

♪ ♪

♪ ♪

♪ ♪

A moray eel doesn't appreciate

The violent tryst outside his front door.

In an incident never before captured on film,

The moment the male withdraws his clasper, the eel grabs it.

The female, finished with him, leaves.

The whitetip will give birth to live young in about a year.

And because she may breed with another male,

Her babies could be from different fathers.

Meanwhile, the hapless male struggles

To yank his clasper from the jaws of his tormentor.

♪ ♪

He manages to pull out,

Getting his white tip the heck out of there.

After her kinky night,

The female whitetip reef shark could use a rest.

She hangs out with the other female and male whitetips

In the sand or among the coral.

♪ ♪

♪ ♪

They catch up on "current" events.

Their muscular gills create a current

That brings in oxygenated water.

That's their superpower.

Most other sharks need to keep moving in order to breathe.

♪ ♪

♪ ♪

♪ ♪

Farther west across the pacific, in the sea of japan,

Sex is less rowdy but no less awkward

For an amorous pair of bamboo sharks,

Caught in this exclusive footage.

The male searches for the source

Of an alluring female scent.

♪ ♪

♪ ♪

He declares his intentions with the usual unsubtle foreplay:

Biting her fin.

She's no prude, but right now she's really not that into it.

She tries to flee.

He doesn't back down, just changes his tactics,

Driving her to the bottom to keep her from slipping away.

♪ ♪

The upside-down couple enters a state of tonic immobility,

A kind of hypnosis common to mating sharks.

The female swoons.

And the male skips the foreplay

And inserts one of his claspers for the main event.

Afterward she tolerates his company.

Soon he'll wander off in search of other conquests,

And she'll hunt for a quiet place to lay her eggs.

♪ ♪

In polynesia's fakarava pass, alone time is hard to come by.

♪ ♪

700 grey reef sharks bask lazily on the current

When they need to relax.

But here, there's another option:

Lounging.

Gliding against the current,

These six-foot sharks can oxygenate their cells

With only minimal effort.

♪ ♪

♪ ♪

This remora, a weak-swimming fish

With a suction cup instead of a dorsal fin, reports for duty.

♪ ♪

♪ ♪

He attaches himself below the shark's belly

Or settles into the stream of water generated by his host.

♪ ♪

♪ ♪

He's here for a free ride and a free lunch,

Nibbling parasites from the shark's scales.

♪ ♪

This rare footage captures a remora

Getting a little too familiar,

Poking the gills to slurp some mucus.

If he's not careful, he could end up as a shark snack

And be a remora no more.

But most sharks have bigger fish to fry,

And some won't even hesitate

To attack and devour their own kind.

This grey reef shark got nailed by a hammerhead

And almost lost his own head.

♪ ♪

♪ ♪

♪ ♪

Another hammerhead victim

Welcomes the remora's dedication

To keeping his wound clean.

Any way you slice it, sharks have complicated,

Surprisingly varied, and often dangerous lives.

Coming up, a shark that racks up

The biggest body count of all,

And the secret hunting techniques

Of a shark that doesn't like to eat alone.

Nighttime belongs to the hunters.

In the maldives,

When the full moon shines over the indian ocean,

The world's largest fish surfaces for a feast.

Zooplankton, microscopic critters,

Dance by the light of the moon.

Cousins of the shark.

But the rays quickly scatter

When the guest of honor arrives.

Rising from a depth of 3,000 feet,

The whale shark, big and hungry as a busload of teenagers,

Can weigh 20 tons.

With his almost five-foot-wide mouth gaping,

He advances, filtering the plankton

And expelling the water through his gills,

1,500 gallons an hour.

♪ ♪

Unlike other sharks, the whale shark's mouth

Is in front of his head rather than below it,

For more efficient filtering.

Whale sharks have 300 rows of tiny teeth,

But they don't use them to eat.

He needs to slurp down one ton of tiny zooplankton a day,

Which means he kills more than any other shark.

♪ ♪

Nighttime is also dinnertime for whitetip reef sharks here.

When darkness falls on costa rica's cocos island,

And their prey can't easily see them,

They gather at the lagoon,

Their predatory instincts in overdrive.

They haven't eaten in days, and they've got big appetites.

♪ ♪

♪ ♪

This agile, five-foot shark can flush out fish

By slipping into the nooks and crannies of a reef,

Swimming backwards, and even doing u-turns.

Individually, these fierce-looking predators

Are mediocre hunters.

So they use the power of numbers and hunt in groups.

Like many sharks, they sense their prey

By feeling pressure waves in the water,

Or by the tiny electrical fields

Emitted by all living things.

This filefish doesn't bother to hide;

If it stays still, the sharks can't detect it.

♪ ♪

♪ ♪

The carangid fish is even bolder.

She doesn't fear whitetips

Because their mouths are too small to swallow her.

Her hunting helps stir up prey for the sharks,

And she's happy to grab their scraps when the feeding begins.

♪ ♪

♪ ♪

Even though they hunt in a group,

The cooperation stops there.

It's every shark for himself.

If prey slips past one,

Another might grab it,

And she's not sharing.

♪ ♪

♪ ♪

♪ ♪

The result is a whitetip feeding frenzy.

They'll bite anything that moves,

And they'll keep it up until dawn.

♪ ♪

♪ ♪

♪ ♪

Together, whitetips rule the reef.

But some loners are also night prowlers.

If you find yourself in shark-infested waters,

Pray that they're greenland sharks

And that you have a thermal wetsuit.

These sharks live in the arctic's icy waters

And are as old as marine dinosaurs.

The nearly 14-foot sharks

Grow no more than half an inch a year,

And could live for 400 years.

Not only is a greenland shark one of the oldest sharks,

It's also probably the slowest fish in the sea.

If she chases you, simply walk away.

Her maximum speed is slower than the average human gait:

Three miles an hour.

And yet she manages to catch seals,

Probably ambushing them while they sleep.

Her hundred or so teeth work like a knife and fork.

Her upper teeth grasp the prey

While the lower ones slice its flesh.

As if things weren't complicated enough,

A parasite has latched onto her eye,

Condemning her to centuries of blindness.

It's a small consolation that her tiny tormentor's glow

Helps the greenland shark attract prey.

♪ ♪

So little is known about this shark

That much of her long life is a mystery.

Finding food can be a struggle, even for apex predators.

But every year or so,

There's a party off the coast of south africa,

And there's a shocking guest of honor.

What's more thrilling than a shark?

A mob of them.

Sharks might have invented crowd sourcing.

Every year, between may and July,

Billions of migrating sardines come to spawn

Off the coast of south africa.

Catering one of the largest feeding frenzies in the world.

Sharks make the guest list.

Hundreds of copper sharks

Swooping through a dense, oily cloud of fish.

♪ ♪

♪ ♪

The sardines try to thwart the attack

By banding together into a tight, shimmering disco ball.

When a shark strikes, the sardines scatter and escape.

Or at least that's the plan.

But the battle's not over.

While the sharks harass the sardines from below,

Cape gannets mount an aerial attack.

Sharks and birds corner the little fishes,

Benefiting them both.

(birds squawking)

Air trapped in their feathers

Hampers the gannets' ability to dive deep,

So they have to strike hard.

They hit the water headfirst with arrow-like posture,

Folding their wings behind them

To minimize the force of impact.

Besieged on all sides, the sardine defense starts to fail.

♪ ♪

♪ ♪

To make things worse,

A bryde's whale crashes the party.

Rising from the depths,

This 15-ton giant devours sardines by the thousands.

♪ ♪

Even the copper sharks

Give this 50-foot behemoth a wide berth.

♪ ♪

And then it's over as suddenly as it began.

In south africa, the sardine run is in full swing.

Meanwhile, in polynesia, sharks there whet their appetites

For another mega-banquet.

In the pass of fakarava, nearby on the reef,

Groupers arrive, ready to spawn.

The grey reef sharks bide their time until nightfall.

(motor running)

The scientists, divers, and cameramen

From the gombessa expedition

Were the first to document this behavior,

After four long years of study.

♪ ♪

♪ ♪

At night, the groupers instinctively know the danger

And try to hide as best they can.

Meanwhile, the grey reefs plot their next move.

These sharks are relentless hunters.

♪ ♪

♪ ♪

When one grouper gets caught, the frenzied mob of sharks

Swirls around it like a dryer full of steak knives.

There are plenty of other groupers ripe for plucking,

But this unfortunate one becomes the sole object

Of their carnivorous desire.

♪ ♪

700 sharks!

That's the biggest shark flash mob in the world.

♪ ♪

♪ ♪

It's a game of cooperation and competition

When the horde gets down to business.

♪ ♪

But this selfish teamwork has an impressive 42% success rate.

Even the most efficient of wolf packs

Snares its prey only 14% of the time.

And unlike sharks, they share the spoils.

♪ ♪

♪ ♪

♪ ♪

♪ ♪

The groupers suffered major losses today.

But the shark horde isn't greedy.

They take only what's strictly necessary for their survival.

♪ ♪

♪ ♪

♪ ♪

♪ ♪

Coming up, life can be tough for sharks,

Even before they're born.

Even though sharks rule their environment,

They start out as helpless babes,

Or maybe not so helpless.

40% of shark species are oviparous, or egg-laying.

During breeding season,

A female may lay them daily or weekly.

The sac, commonly called a "mermaid's purse,"

Is stashed away, safe from roving predators.

Though they've been doing this for millions of years,

It's rarely ever caught on film.

Spirals at each end help the sac cling

So the current doesn't carry it away.

This catshark fetus is several months old

And starting to look like a fish.

All the nutrition it needs is in the yolk sac.

In a few weeks, eyes, mouth and fins will form.

Gills will grow on the side of its head.

For now, the fetus breathes through vessels

That extract oxygen from the water.

♪ ♪

When the yolk sac is empty,

The baby shark will make its debut in the deep blue.

♪ ♪

♪ ♪

After months of incubation,

A baby epaulette will soon show his snout.

♪ ♪

♪ ♪

Witnessing a birth is always a highly emotional experience,

And opportunities to be present

For the birth of a shark pup are rare!

♪ ♪

Sharks have no maternal instincts.

Once he emerges from the capsule,

He must feed and defend himself,

Relying on instinct alone

To face the challenges of life in the ocean.

♪ ♪

♪ ♪

In the bahamas, lemon sharks, up to nine feet long,

Blend into the mangroves of the archipelago.

Every two years, the females return to give live birth

In the place they were born.

Each mom-to-be has been carrying

4 to 17 fetuses for a year.

The lemon shark is viviparous;

Placental connections between mother and growing sharks

Deliver the nourishment they need,

Just like human babies.

♪ ♪

Today's the big day.

♪ ♪

The umbilical-like cords break,

And the babies begin life's great adventure.

Though for now they're confined to the kiddie pool.

♪ ♪

The two-foot newborns are born with teeth

But lack experience to confront the harsh ocean.

Birth is the last time they'll see their mothers,

So their teachers will be trial and error.

♪ ♪

In the privacy of their mangrove ecosystem,

They'll find enough food and be safe from predators.

Although cannibalistic adult lemon sharks

Sometimes raid the nursery.

♪ ♪

At age three or four,

The young will be ready to head out to sea.

♪ ♪

♪ ♪

♪ ♪

Off the coast of north carolina,

A ship's graveyard becomes an arena

For tiny, unborn gladiators.

Sand tiger sharks prize these shipwrecks as a refuge,

Pantry, and occasional tourist destination.

Migrating sharks will sometimes travel more than 1,000 miles

Out of their way to visit these artificial reefs.

Resting, they effortlessly stay afloat,

Gulping air from the surface

To use like a diver's buoyancy control device.

They move in slow motion, but they can strike fast.

♪ ♪

With their pointed snouts and perpetually bared teeth,

Sand tigers look ferocious.

Their teeth, arranged in irregular rows,

Are adapted to snatch moving prey.

Like all sharks, they have multiple rows of teeth

That get continually replaced.

Over a lifetime,

Some sharks may go through 30,000 teeth.

Right now they're ignoring the bounty of fish

Because they hunt by night.

But every sand shark's first meal is its siblings.

♪ ♪

Intrauterine cannibalism is a thing.

When the eggs hatch inside their mother,

The sand tiger smackdown begins.

The strongest embryo will devour its brothers and sisters

Until it's the sole survivor,

Taking sibling rivalry to its darwinian extreme.

♪ ♪

Up next, these sharks

Take a more ninja-like approach to hunting.

The victims of these solo assassins

Never see them coming.

Today marine biologists recognize

About 500 species of shark.

One stands out, literally.

On this sunny coral reef in australia,

A young epaulette shark stayed too long.

The tide's going out.

He's stranded and doomed... Or is he?

♪ ♪

♪ ♪

Nature's gifted him with the ability

To use his fins like feet.

He's actually in his element here,

Hunting for crustaceans and fish

That are really trapped by the receding waters.

♪ ♪

♪ ♪

But his powers go way beyond that.

He can slow his heart rate and limit blood flow to his brain.

Operating on autopilot,

He can survive about an hour without breathing,

At temperatures approaching 90 degrees.

The clock's ticking,

So it's time to cast off into the rising tide.

♪ ♪

♪ ♪

Sharks get creative when it comes to survival.

Some are escape artists, while others roll out the red carpet.

When it comes to hidden sharks,

This one looks more like a frilly oven mitt

Than a stealthy killer.

♪ ♪

The bearded wobbegong's a loner

Who sticks to a few favorite hangouts

Along the australian reef.

He can grow about four feet long.

You can see why he's sometimes called a carpet shark.

The beard matches the carpet,

But those frills do more than camouflage;

They detect ripples from passing prey.

♪ ♪

♪ ♪

By day he lies in ambush,

Biding his time.

Timing is everything.

♪ ♪

♪ ♪

♪ ♪

When he snaps open his mouth,

The suction draws in the unsuspecting prey.

His short, needle-like teeth do the rest.

♪ ♪

♪ ♪

Then he just relaxes until his next course is served.

In south africa,

The pyjama catshark takes a more active approach.

This three-and-a-half-foot shark gets its name

For its pajama-like stripes and cat-like hunting style.

A group of squid, one of her favorite foods.

She hides in their egg bed, camouflaged by her stripes.

She slinks closer and prepares to pounce.

♪ ♪

♪ ♪

Like a tiger, she picks a squid isolated from the group.

♪ ♪

It's not an easy kill.

She rolls it vigorously.

A blast of ink from the dying squid blinds her,

But she's not deterred.

The tussle draws attention from other hungry sharks.

Soon it's like a pajama party gone wild.

♪ ♪

♪ ♪

And one aggressive guest swims off with the prize.

Sharks don't have to worry about ink stains,

But some make an effort to keep their killer good looks.

In palau, some coral reefs become dedicated shark spas,

Cleaning stations where marine life

Can get pesky parasites removed,

No appointment necessary.

And this grey reef shark is a big fan

Of the services offered by the cleaner wrasse.

These tiny fish earn their five-star reviews

With their special brand of skin, jaw, and gill care.

The shark could easily swallow the fish,

But then, who would he get to floss his teeth?

The shark stays healthy

And the wrasse gets a good parasite meal.

Everyone benefits.

During the treatment, the shark has to keep swimming upward,

Facing the current, or he'll sink.

The wrasses keep busy and alert.

♪ ♪

Some sharks make a real effort to avoid devouring the help.

Coming up, life can be tough, even for apex predators.

And the private life of a movie star

Can be less than glamorous.

Sharks seem like born survivors,

Showing up at the right place at the right time.

They know how to exploit an opportunity.

For a few months each year,

Leatherback turtles leave the deep sea

To lay eggs on the beach;

A ritual this tiger shark looks forward to every year.

Exhausted from hauling herself on shore and burying her eggs,

The turtle heads back to the open ocean.

Even on her best day, she's no match for a tiger shark.

♪ ♪

The attack is swift and brutal.

Beginning with her paddle-like legs,

Exposed and unprotected.

The tiger shark's jaws can even pierce the turtle's shell.

♪ ♪

♪ ♪

♪ ♪

The shark circles the carcass to mark its territory.

But other tiger sharks risk joining the feast.

♪ ♪

♪ ♪

Tiger sharks will eat anything, from turtles to tires.

Within minutes, there's nothing left but the empty husk.

♪ ♪

♪ ♪

♪ ♪

With its highly developed olfactory lobes,

A tiger shark can sniff out minute scent molecules

Within a radius of 450 yards.

And here in south africa,

One tantalizing scent is like catnip

To these typically reclusive tiger sharks.

This fierce predator won't turn its nose up

At the chance to scavenge a whale carcass.

♪ ♪

♪ ♪

The energy-rich blubber in the head is a delicacy,

The pièce de résistance of this 40-ton feast.

♪ ♪

♪ ♪

The fat of the whale flesh can spread on the currents

Over several dozen miles.

♪ ♪

♪ ♪

♪ ♪

♪ ♪

But the tiger shark loses its appetite

When a great white makes a guest appearance.

It's a competitor he doesn't want to tangle with.

The celebrity of the shark world,

The great white shark is larger than life,

Chum for the hungry press,

Always described in superlatives:

Biggest...

Baddest...

Scariest.

♪ ♪

♪ ♪

♪ ♪

But when the cameras are off,

The most dominant, curious, and fascinating shark on the planet

Is, above all, a highly effective hunter.

♪ ♪

The great white attacks with speed,

Precision and amazing accuracy.

♪ ♪

♪ ♪

Using sunlight as camouflage,

She rockets through the deep,

Ramming her prey at 25 miles per hour,

Driving it above the surface.

But for apex predators,

Great whites are surprisingly vulnerable.

Because they live only 30 to 40 years and mature late,

Females have only a brief window to give birth.

And overhunting by humans

Has put the iconic species in peril.

♪ ♪

♪ ♪

To witness the secret lives of sharks up close

Is to discover their vulnerable side...

Their unrivaled skills...

And their keen intelligence.

♪ ♪

They're the predators we fear most,

Thriving in the deep ocean

And the shallows.

♪ ♪

But there's no denying their magnificent wildness.

♪ ♪

Without sharks,

The biodiversity of earth's oceans would suffer.

♪ ♪

Threatening not only the future of the marine world...

But also our own.

Captioned by side door media services