Cephalopods Deadly 360

This is Deadly 360,

the show that pits three of the world's deadliest predators

against their prey.

Examining their hunting strategies and escape tactics from every angle.

We find out why a hunt succeeds.

And why they sometimes fail.

One thing's certain - prey animals are anything but sitting ducks.

Their defensive strategies keep them alive.

And push predators to the limits.

Prepare for Deadly 360.

This is Deadly 360 mission control, where all of today's action

and analysis takes place.

We have access to some of the most enthralling hunts caught on camera.

I've recreated three of

the most exciting and analysed them in true 360-degree style.

The predators have to find food or they won't make it.

In the wild world, surviving is the greatest challenge.

I present to you the cephalopods.

Octopus, cuttlefish and squid.

Probably the most intelligent invertebrates.

We'll witness a squid assault,

find out why this cuttlefish is a master of disguise,

and uncover the hidden horror under an octopus's arms.

They look invincible but there's a continual arms race

in nature, ensuring that prey animals

evolve spectacular ways of taking care of themselves.

Today's defenders include an armour- clad warrior of the deep - the crab.

A shrimp with a cloak of invisibility.

And an army of fish that use numbers to outwit the enemy.

Three different prey. How will they fare against our predators?

I've introduced you to our contenders.

It's time to meet our first deadly duo going head to head.

For the predators, the most well-known cephalopod, the octopus.

A hunter with clever adaptations.

Up against it is this.

A crab, loaded with heavy duty weaponry and clad in armour.

But which animal has the edge in the race for life?

It's time to go Deadly 360.

We look at a critical moment.

We're in shallow waters offshore.

A crab has strayed and there's an octopus closing in.

There's no escape for the crab. It's going to have to fight.

But will those claws be any good against a hungry octopus?

It looks like the prey is in serious trouble.

But how did it get there and is there any chance it might survive?

To answer these questions, we'll wind back to

the start of the hunt and find out what leads up to this strike.

Where are we?

This hunt is taking place

around the UK, just off the south coast here.

It's summer so the sea temperature's high,

which suits our octopus, who prefers temperate waters.

Rocks and seaweed provide cover, good for both hunting and hiding.

So that's our location.

What attributes do our predator and prey have

that will give them an advantage?

First up, the octopus. It's a complex predator.

It has eight arms for grasping its prey

and a beak with venomous saliva, plus other surprising abilities.

More on those later.

So that's our predator. Time to find out about its prey's defences.

The crab's most obvious way of fending off an attack

is with its two pincers, which exert a powerful crushing force.

Add to that an armoured shell, and it's anything but an easy meal.

Based on that, this will be an interesting hunt.

Let's see how it unfolds. We're back at the start of the day.

Our predator is in its den, tucked away among the rocks.

An octopus has no bones at all in its body, which means it can

slip that soft, rubbery form into the tiniest of gaps.

A useful adaptation, but a soft body is vulnerable to attack.

It needs to be careful, particularly if it hunts for one of these.

The crab is armed with those brutal pincers.

A more effective defence for the crab is to hide.

Its colouring makes it hard to pick out.

As long as the octopus can't see it, it's safe.

It looks like another crab is approaching.

Crabs are territorial. They'll fight rivals who muscle in on their patch.

You can look at this crab's pincers. They have a serrated edge.

They can break into a mussel's shell.

It's not uncommon for a crab to have a pincer

or a leg snapped off in one of these squabbles.

The invaders back down but the fight has distracted

the first crab and allowed the octopus to sneak up.

It has to hold its prey whilst avoiding those claws.

How will it do that? Let's take a closer look at this predator.

An octopus's eight arms are remarkable tools.

The octopus has no internal skeleton

but because the muscles are packed so tightly

it has an extraordinary amount of strength.

Because it doesn't have hard bones, it can twist those arms.

It has unrestrained flexibility.

On the underside of each one of those arms are suction cups.

They're muscular and possess taste buds.

It's almost as if it is covered in tiny tongues,

that it can place into any crack to find out what's inside.

It may seem that it is a soft animal

but it's presenting a master class in sensitivity and strength.

Now that the crab's been spotted,

hiding under a rock will be little defence

against the octopus's arms, which could grab it.

The crab's next instinct is to make a run for it.

An octopus's locomotion is slow but it has one method of speed.

It drives water out of its body through the siphon,

which can make it go up to 25 miles an hour.

That's more than enough to catch up with the crab.

If the prey can't run, its only option is to fight.

The octopus needs to be careful - those pincers could do some damage.

That's worth another look.

The octopus moves with great speed and envelops the crab in its arms.

The crab simply has no chance to use those pincers.

Is that hunt over? Maybe not. The crab has a last line of defence.

This is an edible crab. It is alive, although it's quite compacted,

drawing all its limbs in to protect itself.

It's got this pie-crust shape and a pinky or orange colour.

The first thing you notice is the pincers. They are massive.

There are fishermen missing fingers due to claws like these.

Once a crab has been enveloped,

those pincers will be of limited use.

The octopus wants to get to the soft body parts inside this shell,

and that armour is now the crab's last line of defence.

It's got two constituents. The first is a protein called chitin

which can be rubbery, and the other is calcium carbonate.

It is hard but has a tendency to be brittle.

This shell could be cracked and then the crab is going to be helpless.

Let's see if our octopus can breach these defences.

The hunt is a race against time.

Every minute the octopus maintains that grasp

on the crab, it's also vulnerable to attack.

The first thing it'll do is carry the crab to its den.

This should give it more time to crack through that body armour.

This needs to be done with precision to prevent the crab

launching a counter-attack.

The octopus has some tools underneath all of those arms.

To find out how this works,

we'll head to the business end of the octopus, the mouth.

Inside there are two structures. One is the radula,

which can wear away the crab's shell.

The other is covered in papilla.

These can be used to drill a hole into the crab's soft body.

Next, the octopus will inject a venom into the crab.

It might look like nothing's happening,

but the prey is being torn apart.

It's taken the octopus about 20 minutes, but it's broken through

the crab's defence and now it

devours the flesh inside.

The octopus might appear to be a soft-bodied sort,

but there's nothing soft about this predator.

Imagine something drilling a hole in your head

and injecting a toxin that destroys you.

Not a nice way to go.

The crab had decent vision. Pincers. And that tough outer shell.

The octopus was equipped with sucker-lined arms,

its radula and that lethal toxic venom.

The crab may have been well protected but this time,

the octopus's surgical skills were enough to break in and get its meal.

Now on to our next pair of hunters locked in a battle for survival.

For the predators, we have a monster of the deep.

It's the Humboldt Squid.

And up against it is this. A massive shoal of open water fish,

each one a swimmer with evasion techniques.

But which has the edge in the race for life?

It's time to go Deadly 360.

We've dropped right into a deep sea battle. It's mayhem!

There are fish and squid rocketing around like heat-seeking missiles.

It's almost impossible to figure out what's going on.

We need to wind back the hunt. It'll make sense of what we've seen.

Let's start with the location.

We're off the coast of Mexico.

We're 30 metres down so there's not much to see

but there is a seabed below. Will that be a factor in this hunt?

That's the arena for our gladiatorial contest.

What weapons and defences do the two animals doing battle have?

First the Humboldt squid. It grows up to two metres long.

It's fast and has nasty arms.

All of that makes our predator a scary prospect.

What does our prey have? Their main defence is to shoal,

using strength in numbers to increase their survival chances.

They also have a detection system.

It won't be easy for any predator to pick off that prey.

That's the background, let's get the hunt under way.

We're at the start of the action and it's the fish that are hunting.

They work together to feed on tiny crustaceans called krill.

But they could soon be the ones in the firing line,

cos there's a Humboldt squid in the area,

and from the shapes in the background

it looks like it's not alone.

Hundreds of squid head towards the fish, also operating as a group!

Humboldts are highly intelligent.

They hunt together in vast packs, sometimes over 250 squid strong.

And each one is equipped with a whole lot of arms.

Oh! That's definitely worth another look!

As the squid splays open those eight arms,

there are also two hidden tentacles that we can't see here.

What we can see are those suction cups.

Each one is lined with a row of unbelievably sharp teeth.

When they latch on there's almost no chance its victim will escape.

They'll drag it back towards the mouth

where the real horror show starts.

The bodies of octopus and squid are soft, apart from the tiny teeth that

line the sucker cups on their arms and tentacles, and this monstrosity.

This is the beak of a deep-water squid

and it really is a fearsome tool.

It's made of chitin, often found in the natural world.

It's soft and pliable towards the end where it binds to the muscles

and rock-hard and very, very pointy at the end of the beak here.

This section kind of looks like a parrot's beak,

but actually in function, it is quite different.

They use it to bite clean through the spinal cords of fish,

which paralyses them instantly,

and then to chomp them apart and feed them back here into the mouth.

It's interesting that it can generate so much force

and it's powered by muscles that look like jelly.

But cos they've got a circular strap-like formation like this,

they can generate enormous force by just clenching

and that drives the beak closed

and takes a really sizable bite.

As I found out when I found one of these in the wild

and got bitten!

Have a look at this.

It's got its tentacles around my arm

and I can feel the gripping of those teeth.

Actually, you can feel it even through the chainmail suit.

And in here, that's where that snapping beak is - just there.

I'm going to take great care not to get my fingers close to it,

cos I think I'd lose them.

It's actually... Arrrrgh! Dear me! This is...

Arrrrgh! The strength of the beak!

It just actually bit me right through the chainmail suit.

Actually, I got off quite lightly there!

They have been known to break bones,

even through the chainmail suit!

So what chance does the fish have? Let's see.

The Humboldt hunting party is closing in fast on its prey.

Like octopus, these squid have siphons to jet-propel themselves

through the water either forwards or backwards.

The fish's response to the threat is to stick together.

Moving in a vast pulsating shoal makes it much harder

for the squid to pick out a single target,

and helps to minimise casualties.

But remember, the squid are also working as a team,

trying to drive the fish up against the rocks

in order to split up the shoal and give themselves the advantage.

It looks like an all-out assault is about to begin.

But once the carnage starts, what other mechanisms do the fish

have to avoid being hooked?

It might seem that the life of a small fish is pretty rubbish.

I mean, it kind of seems like their only purpose is to get eaten.

But it doesn't mean they're defenceless.

They do have one sense that allows them to see the world around them

in a completely different way to us.

Running down the length of their body is a lateral line.

In some species of fish it's clearly visible,

but if you look at it under a very high powered microscope,

what you see are tiny hairs, capable of discerning movement in the water.

As a predator swims through the water, it creates a wake,

very much like a boat does, and the fish can sense it coming.

The second it feels a threat nearby

the fish can make a dart for safety.

Let's see if the squid is going to have any chance of catching

these slippery subjects.

The first squid moves in and the full-out assault begins.

The prey's defences are being tested to the limit.

The fish may be fast but squid are also attacking at phenomenal speed.

If we slow the action down,

their strikes are almost too fast for us to see.

They strike using those arms and tentacles,

grab the fish and drag it back towards their beak.

It's all over in about 20 milliseconds.

Even with their lateral line and a body built for high-speed evasion,

it's difficult for the fish to cope with such a strike.

But, it looks like the attack is coming to an end.

Either they have eaten enough or they've run out of puff.

Incredibly, despite the attack from hundreds of hungry squid,

it appears that many of the fish have survived.

A smaller shoal might've been wiped out,

but the sheer numbers working together in this group

ensured lots of fish made it out alive.

It's very difficult to call a clear winner in this contest.

The Humboldt squid managed to eat its fill,

but there was still plenty of fish around to manage to breed

and bring on another generation of fish, so they succeeded too.

Strength in numbers worked.

I guess the only fair result for this is to call it a tie.

So the fish -

Speedy swimming skills,

a lateral line detection system,

and strength in numbers.

And they were up against the Humbolt's teamwork,

rapid-fire arms and tentacles and that flesh-slicing beak.

The squid may have got their meal

but the shoal was large enough to take the hit

so this time the honours were even.

And this is our last deadly duo

locked in a battle for life or death.

Representing the predators, it's the cuttlefish.

It looks like an alien from a horror film and it kills like one too!

And up against it is this.

A shrimp - it may be small, but it's armed with a secret superpower.

But which animal has the edge in the race for survival?

It's time to go 360.

Again, we join the hunt in its final stages.

The cuttlefish is moving towards its prey.

The shrimp's either unaware or unconcerned.

But it only has moments left to react if it's to survive.

By now you know there's a lot more to a hunt

than just the final strike.

What are all the hidden factors that influence

what happens in the next few seconds?

To find out we have to wind back to the start and dissect the action.

Let's start by checking out the location.

For this final hunt we've moved to the North Sea, here,

just off the coast of Denmark.

We're in the shallows, not far offshore.

The seabed's littered with rocks

so plenty of hiding places,

but also lots of good spots to set up an ambush.

So that's the location. Let's meet the animals.

First our predator.

The cuttlefish has those trademark cephalopod arms,

two hidden striking tentacles and a razor-sharp beak.

Plus, it can do some incredible things with its eyes

and its skin - more on those later.

So it's clear, we're dealing with another well-equipped predator.

But how's our prey going to try and neutralise the threat?

Well, the shrimp is small and quick.

Their main defence is an impressive camouflage technique

which makes them very hard to spot, let alone catch!

With two such talented animals, this hunt is going to be close.

Let's see what happens.

We're now right back at the start of the hunt.

The cuttlefish is patrolling its territory,

which can cover up to 20,000 square metres,

meaning a lot of places for a tiny animal like a shrimp to hide!

There aren't many signs of life at the moment, or are there?

To get the full picture, we need to zoom in.

You can see the shrimps have been there all along,

but from this close, you can see why they're so hard to detect.

They're practically see-through. How do they manage that?

Usually in nature, camouflage is about disguising yourself

to look like your environment.

But the shrimp goes one better.

When you look at it, you can see the environment

it lives in and there's an interesting reason -

the exoskeleton of a shrimp is made from the same material

you'd find in an insect's exoskeleton,

but it's very thin and pliable.

The shell is transparent,

and the blood's colourless,

so you can see through the shrimp to the world beyond.

It is pretty much invisible, incredible!

So, certainly not helpless.

Let's return to the action.

There are loads of shrimp in the area,

but with their powers of speed and invisibility,

they seem unconcerned there's a predator nearby.

So, is this hunt over before it's even started?

Well, no, of course not,

cos the cuttlefish has its own special superpower at its disposal -

Its eyesight. The cuttlefish's vision

is some of the most highly developed

of any animal in the whole natural world.

They can see well beyond the range of human vision,

in particular, they can detect light that has been twisted.

This is called polarisation.

It's what happens to light waves hitting the transparent shrimp.

They might be nearly invisible to us,

but to a cuttlefish, the shrimp stand out in sharp contrast

to their background, making them easy to identify.

So the shrimp's cover is blown,

but the cuttlefish still has to get within striking range.

That's difficult for the conspicuous cuttlefish

and the shrimp has very sharp eyesight.

So how's it going to manage it?

The cuttlefish's ability to change colour

has no equal in the natural world.

It's achieved in much the same way as other animals

such as chameleons.

Beneath the surface of the skin

are special colour-containing cells,

but what's unusual is how quickly the cuttlefish does it.

This is unbelievably dramatic,

look at this - the entire colour has changed in a second.

There are also special bunches of muscles at the skin

which can be used to draw up spiky shapes or make it smooth.

So it uses these in tandem to create incredible camouflage,

blending in perfectly with its background.

Let's see how it puts these into effect.

The cuttlefish used its remarkable eyes to pick out and target

a single shrimp.

Now it'll use that camouflage

to try to get close enough to make a strike.

First it will use that remarkable colour change

to match its environment.

It'll twist its tentacles to create weird shapes.

Next it'll control its buoyancy

to use the current to float towards its prey.

It'll use that siphon to adjust its trajectory.

So there's very little turbulence

in the water for the shrimp to sense.

To fully appreciate all this, though,

we need to see things from the shrimp's point of view.

Let's go to shrimp-cam!

All the shrimp can see is floating weed, drifting closer -

a brilliant disguise.

Now the cuttlefish has plenty of time to lock on target,

extending its two striking tentacles, and...

Wham!

Let's see it again.

After such a slow and considered approach,

the final strike was devastatingly quick.

Let's see it from shrimp-cam.

This is the last sight the shrimp will see.

It's snatched up by those tentacles,

dragged back by the arms to the mouth,

eaten, and then the cuttlefish heads off to find another victim.

It'll take more than a bit of see-through camouflage

to outwit the cuttlefish.

With its incredible skills and techniques,

it's one of the most accomplished hunters on Deadly 360.

So, the shrimp had its small size, sharp vision,

and an almost invisible body.

But the cuttlefish overcame these defences, with its all-seeing eyes,

clever camouflage techniques and devastating final strike.

The cuttlefish always had the advantage.

Despite being almost invisible, the shrimp just never saw it coming.

The squid, octopus and cuttlefish are continually-surprising animals.

They have an unparalleled ability to change their shape and colour.

Some have venom and sharp biting beaks, and in their element,

they're truly lethal killers.

That's all we've got time for.

Join us next time, as three more pairs of animals go head-to-head

and we analyse the action, Deadly 360 style.

Subtitles by Red Bee Media Ltd

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