0:00:02 > 0:00:04My name's Steve Backshall.
0:00:06 > 0:00:07You can call me Steve.
0:00:10 > 0:00:12I'm on a mission to find the Deadly 60.
0:00:12 > 0:00:14That's 60 deadly creatures.
0:00:14 > 0:00:17I'm travelling all over the world.
0:00:17 > 0:00:20And you're coming with me every step of the way.
0:00:23 > 0:00:24Shark!
0:00:29 > 0:00:33We're skimming over chilly South Australian seas.
0:00:33 > 0:00:34Around about here.
0:00:34 > 0:00:38Although my crew's about to take off at the moment!
0:00:38 > 0:00:42Today's programme has something of a watery theme
0:00:42 > 0:00:44though there are gonna be a few surprises.
0:00:44 > 0:00:46Stick with it, guys!
0:00:50 > 0:00:54First up is an animal that's deadly because it's quick.
0:00:54 > 0:00:57You're looking at the fastest fish in the seas.
0:00:57 > 0:01:00They're all submarine speedsters,
0:01:00 > 0:01:02but the fish I'm after is turbo-charged,
0:01:02 > 0:01:05clocking up speeds of over 70km an hour.
0:01:05 > 0:01:08Ladies and gentlemen, I give you...
0:01:08 > 0:01:10the tuna!
0:01:10 > 0:01:13But first, a bit of Deadly 60 science.
0:01:13 > 0:01:18The big enemy of anything trying to travel fast in water is drag.
0:01:18 > 0:01:21That is the force of the water holding you back
0:01:21 > 0:01:23as you try and move forwards.
0:01:23 > 0:01:26To get around that you have to be streamlined.
0:01:26 > 0:01:30In the air that's aerodynamic, in the water hydrodynamic.
0:01:30 > 0:01:33The tuna is just about the most perfect example
0:01:33 > 0:01:35of a hydrodynamic fish.
0:01:35 > 0:01:38I, on the other hand, am not that streamlined.
0:01:38 > 0:01:42So, theoretically, if I was to get in there and try and travel fast,
0:01:42 > 0:01:44I should be hammered by drag.
0:01:45 > 0:01:51So, we already know that tuna can travel up to around 70km's an hour,
0:01:51 > 0:01:53which equates to about 38 knots.
0:01:55 > 0:01:57OK, Captain, hit it!
0:02:01 > 0:02:04You can see as we start to build up speed,
0:02:04 > 0:02:09automatically the water's pushing back against me
0:02:09 > 0:02:12and I'm really struggling to hold on.
0:02:13 > 0:02:16I'm actually already losing my trunks!
0:02:16 > 0:02:20Ha-ha, I don't think I tied them on quite strong enough!
0:02:20 > 0:02:22Go a bit faster!
0:02:22 > 0:02:23Oh dear!
0:02:23 > 0:02:253.9 knots.
0:02:25 > 0:02:28I've got one hand holding my trunks on
0:02:28 > 0:02:32and the other one holding onto this rope!
0:02:34 > 0:02:37What speed are we at, boys?
0:02:37 > 0:02:39That's 4.7 knots, Steve.
0:02:39 > 0:02:45Well, I've still got hold of the rope but I've only just got...
0:02:45 > 0:02:47How fast now?
0:02:47 > 0:02:48What's that?
0:02:48 > 0:02:496.8.
0:02:49 > 0:02:50OK.
0:02:50 > 0:02:53- You've got nice buns, Steve. - Seven miles an hour.
0:02:53 > 0:02:55Aaah!
0:02:56 > 0:02:59- I've lost my trunks! - Lost his trunks!
0:03:00 > 0:03:04This is not good. I hope you can't see my bottom!
0:03:05 > 0:03:09OK, so we're now going about a tenth of the speed
0:03:09 > 0:03:12that a tuna can go full whack.
0:03:12 > 0:03:16It's almost pulling my arms out my sockets!
0:03:16 > 0:03:18And I'm absolutely naked!
0:03:18 > 0:03:22Ha-ha! My trunks disappeared hours ago.
0:03:22 > 0:03:23Oh!
0:03:23 > 0:03:27And, um, I really hope there's no one watching round here
0:03:27 > 0:03:29cos I'm gonna get arrested.
0:03:29 > 0:03:31How fast now, Mark?
0:03:31 > 0:03:34- Seven knots.- Seven.
0:03:34 > 0:03:35How fast?
0:03:36 > 0:03:38- Seven!- No!
0:03:38 > 0:03:40That's rubbish!
0:03:40 > 0:03:42- Switch faster.- Aah!
0:03:42 > 0:03:44He's gone.
0:03:44 > 0:03:46He's gone, Mark, he's gone.
0:03:46 > 0:03:47What's that?
0:03:51 > 0:03:54Shall we just leave him in there?
0:03:54 > 0:03:55See you, Steve!
0:03:55 > 0:03:57Bye, Steve!
0:03:57 > 0:03:59- Bye!- Bye!
0:03:59 > 0:04:01He's got a nice bum though, hasn't he?!
0:04:01 > 0:04:03Yeah, I noticed. He must work out.
0:04:05 > 0:04:08What was our final speed when he let go, Mark?
0:04:08 > 0:04:108.5.
0:04:10 > 0:04:128.5, oh, he did quite well.
0:04:12 > 0:04:14Not bad for a beginner.
0:04:14 > 0:04:19I think that pretty much proves that unless you're streamlined
0:04:19 > 0:04:21you ain't going nowhere in the water.
0:04:21 > 0:04:25And it also proves why fish don't wear swimming costumes!
0:04:25 > 0:04:29You better not film this when I try and get out the water.
0:04:31 > 0:04:35So, so far we've proved that I can't swim.
0:04:35 > 0:04:37As well as a tuna!
0:04:39 > 0:04:40But I can't dry off yet
0:04:40 > 0:04:45cos I still wanna get in the water with these amazing creatures.
0:04:47 > 0:04:52Growing up it never really occurred to me that the fish in these tins
0:04:52 > 0:04:56are some of the most special and some of the fastest in the seas.
0:04:56 > 0:05:01Unfortunately they're prize food which means they're becoming rare.
0:05:01 > 0:05:05Fishermen, attempting to make sure they don't become extinct,
0:05:05 > 0:05:08have started keeping tuna in these big nets,
0:05:08 > 0:05:12giving me a unique opportunity to get close to them.
0:05:22 > 0:05:25There are lots of different types of tuna.
0:05:25 > 0:05:29The ones swimming round in here are about as big as me,
0:05:29 > 0:05:33but the biggest ever was heavier than a horse!
0:05:33 > 0:05:36This is extraordinary! There's hundreds of them.
0:05:39 > 0:05:44Each one of these tuna weighs almost as much as me
0:05:44 > 0:05:46but they swim effortlessly.
0:05:46 > 0:05:48Just gliding past me.
0:05:48 > 0:05:50They're barely swimming, look!
0:05:52 > 0:05:53I feel like fish food!
0:05:53 > 0:05:55Look at that!
0:06:01 > 0:06:03Being up close to them under water
0:06:03 > 0:06:07makes it easy to see why they're deadly predators.
0:06:07 > 0:06:12They are the perfect shape, nothing sticks up of it to slow them down.
0:06:12 > 0:06:15So they move with just a flick of their tail.
0:06:15 > 0:06:17Awesome! Ha-ha!
0:06:18 > 0:06:23Luckily, tuna fish eat small fish like sardines,
0:06:23 > 0:06:27if I was a sardine now, I'd last about a second.
0:06:29 > 0:06:32Tuna accelerate faster than a sports car.
0:06:32 > 0:06:36And they've got the best eye sight of any bony fish.
0:06:36 > 0:06:41So, if there are sardines around, things are gonna get pretty hectic.
0:06:48 > 0:06:53The tuna is as close to a torpedo as you'll find in the animal kingdom.
0:06:53 > 0:06:54Look at them go!
0:06:55 > 0:06:59They'll pick out the stragglers on the outside of the shoal.
0:06:59 > 0:07:04If a sardine loses his buddies for even a second, WHAM! Munched.
0:07:27 > 0:07:29Great stuff!
0:07:29 > 0:07:33I feel like I've been in a subaqua version of Top Gear!
0:07:33 > 0:07:36The tuna is kind of like the Porsche of the seas.
0:07:36 > 0:07:39They accelerate faster and can be almost as big
0:07:39 > 0:07:41and they can even cost more.
0:07:41 > 0:07:44And they're definitely going on my Deadly 60!
0:07:49 > 0:07:52The world's most hydrodynamic fish.
0:07:52 > 0:07:56A streamlined super speedster of the sea,
0:07:56 > 0:07:58the tuna is on the Deadly 60.
0:08:09 > 0:08:13Now, there are some pretty odd animals in Australia.
0:08:13 > 0:08:16If you're more used to foxes and badgers.
0:08:16 > 0:08:19I mean really, really odd.
0:08:25 > 0:08:28But the animal we're really looking for
0:08:28 > 0:08:33is probably the weirdest animal we'll have on the whole Deadly 60.
0:08:33 > 0:08:37In fact, I reckon it's probably the weirdest animal in the world.
0:08:37 > 0:08:41Now, I've tried to them once before and, to be honest,
0:08:41 > 0:08:44it was just about impossible.
0:08:44 > 0:08:47They pop up to the surface for a couple of seconds
0:08:47 > 0:08:49and then completely disappear.
0:08:49 > 0:08:52So, this time round we've got a bit of an advantage.
0:08:52 > 0:08:55we're actually gonna try and catch one.
0:08:55 > 0:08:59With our nets set, now it's a waiting game.
0:08:59 > 0:09:01But what are we waiting for?
0:09:03 > 0:09:05A platypus.
0:09:06 > 0:09:11Yes, you are looking at a real animal. It swims like a beaver,
0:09:11 > 0:09:15it paddles with webbed feet and it's even got a bill like a duck.
0:09:15 > 0:09:20Except this bill is packed full of electroreceptors.
0:09:24 > 0:09:27And why deadly? Well, it's got highly venomous spines
0:09:27 > 0:09:30and if a platypus stings you with one of these
0:09:30 > 0:09:33it's gonna really, really hurt.
0:09:35 > 0:09:39The sun's just setting and this time of day, dusk,
0:09:39 > 0:09:41is when platypus are the most active,
0:09:41 > 0:09:44out foraging and looking for food.
0:09:44 > 0:09:49The guys think there's a platypus burrow under these logs over there
0:09:49 > 0:09:53and a fair few adults use this pond regularly so we're really hoping,
0:09:53 > 0:09:57with the net in the water, we stand a good chance of catching one.
0:09:57 > 0:10:01Our challenge to find one is that they are very rare,
0:10:01 > 0:10:03very shy and very difficult to spot.
0:10:04 > 0:10:06So, no problem there, then.
0:10:09 > 0:10:14After hours of looking, early next morning we think we spot one.
0:10:14 > 0:10:17Oh! What's that in the middle there?
0:10:18 > 0:10:19There it is, Steve.
0:10:19 > 0:10:20Yes, yes.
0:10:22 > 0:10:24Awesome! Well spotted, James.
0:10:26 > 0:10:29Look, it's quite close.
0:10:29 > 0:10:31- OK, um...- This is great.
0:10:31 > 0:10:38It's just after dawn and our first platypus has finally popped up, just in the middle of the lake.
0:10:38 > 0:10:40James, our director, spotted it.
0:10:40 > 0:10:44- He's looking very chuffed with himself.- Thought it was a duck!
0:10:46 > 0:10:48- Is it?- No, it wasn't!- It's a duck!
0:10:48 > 0:10:50It is, it's a duck!
0:10:50 > 0:10:53Stupid idiot, I told you it was a duck!
0:10:53 > 0:10:56They look similar, don't they?
0:10:56 > 0:10:58It's the bill, it's the bill!
0:10:58 > 0:11:02If it's a duck it's just gone completely under water
0:11:02 > 0:11:05and come back up again. Yes, it is!
0:11:05 > 0:11:07- It's a duck.- It's a duck!
0:11:08 > 0:11:11I thought I'd spotted something.
0:11:11 > 0:11:14He's eminent biologist!
0:11:14 > 0:11:17It's my eye, it's a bit of sunlight reflecting.
0:11:17 > 0:11:22It's very hard to actually determine whether it's a duck or a platypus.
0:11:23 > 0:11:24How stupid do you feel now?
0:11:24 > 0:11:26Quite stupid!
0:11:29 > 0:11:31Oh, well. No platypus.
0:11:31 > 0:11:34But then, a surprise.
0:11:39 > 0:11:41Wildlife watching out here,
0:11:41 > 0:11:45you get a more interesting class of local turn up.
0:11:45 > 0:11:47Grey kangaroo.
0:11:47 > 0:11:52Just come here to check us out and drink some of our leftover coffee.
0:11:54 > 0:11:59You do know that you're taking our attention away from platypus?
0:12:02 > 0:12:04Honestly, look, no.
0:12:04 > 0:12:05Let go!
0:12:06 > 0:12:10There'll be none of that stuff going on with my boom.
0:12:10 > 0:12:13- How many sound booms...- I think...
0:12:16 > 0:12:20I think this kangaroo's getting quite friendly with Richard's boom!
0:12:20 > 0:12:24Seems to like it, Rich! I think they're becoming pals.
0:12:24 > 0:12:26It looks like me granny!
0:12:26 > 0:12:31Still no platypus, but there are lots of other cool animals about.
0:12:31 > 0:12:35Max here is lucky enough to live here at the sanctuary,
0:12:35 > 0:12:37surrounded by amazing animals everyday.
0:12:37 > 0:12:41They've found and captured something really cool for us.
0:12:41 > 0:12:42What's here, Max?
0:12:42 > 0:12:45- Trapdoor spider.- Trapdoor spider?!
0:12:45 > 0:12:49If you haven't seen one of these before, this is really awesome.
0:12:49 > 0:12:54Mark's got his special close up camera to get a look at this.
0:12:54 > 0:12:57Let's unveil it.
0:12:58 > 0:12:59There he is.
0:12:59 > 0:13:01Oh, look at that!
0:13:03 > 0:13:05That is an absolute monster!
0:13:06 > 0:13:08Oh!
0:13:08 > 0:13:11This is only a tiny little spider
0:13:11 > 0:13:14but you can see it really means business.
0:13:14 > 0:13:17Um, the fangs, what do you think of that, Max,
0:13:17 > 0:13:21look at the size of those fangs. Aren't they huge!
0:13:21 > 0:13:24- Yeah.- Do you think that would hurt if it bit you?
0:13:24 > 0:13:25I think it would too.
0:13:25 > 0:13:28I think that would be very, very sore.
0:13:29 > 0:13:33This one at the moment, I'm certainly not gonna put this
0:13:33 > 0:13:36on my hand because I would definitely get bitten
0:13:36 > 0:13:38and actually you can see,
0:13:38 > 0:13:41look at that on the left fang, is that venom beading up,
0:13:41 > 0:13:46dripping down the end of the fang! You see that about to drip off?
0:13:47 > 0:13:48Wow!
0:13:50 > 0:13:54I love your little camera, Mark. It's absolutely amazing.
0:13:54 > 0:13:58It's coming in for some use today, isn't it?
0:13:58 > 0:13:59Look, a side shot there.
0:13:59 > 0:14:03The size of the head and those chelicerae,
0:14:03 > 0:14:06the jaws that drive the fangs are massive.
0:14:06 > 0:14:09They're really like enormous muscles,
0:14:09 > 0:14:12if you can imagine the chelicerae being huge biceps
0:14:12 > 0:14:15that are driving those fangs home.
0:14:15 > 0:14:18This is a mean little spider.
0:14:21 > 0:14:24Of course the really wild thing about this
0:14:24 > 0:14:29is that you don't usually find them just out wandering like this.
0:14:29 > 0:14:34Let's see if we can get it up onto this piece of bark, here.
0:14:34 > 0:14:39The really cool thing about the trapdoor spider is,
0:14:39 > 0:14:42I mean although now it looks like an utter monster,
0:14:42 > 0:14:46the way it hunts is in a burrow that's covered up
0:14:46 > 0:14:51with a little disc shaped door and when an insect wanders past
0:14:51 > 0:14:54it will come shooting out at a great speed.
0:14:54 > 0:14:56Grab the insect and kill it.
0:14:56 > 0:14:57It's big.
0:14:57 > 0:14:59It is very, very big, isn't it?
0:14:59 > 0:15:01I tell you what, though,
0:15:01 > 0:15:06I think we should let this fella disappear off into the bushes.
0:15:07 > 0:15:10- What do you reckon, Max, let him go? - Yeah.
0:15:12 > 0:15:14Let him go.
0:15:18 > 0:15:19Well done.
0:15:19 > 0:15:20Good job!
0:15:20 > 0:15:25One of the most venomous spiders in Australia, and the world.
0:15:25 > 0:15:28There's just so much to choose from round here!
0:15:29 > 0:15:36We're now 25½ hours into our search for platypus
0:15:36 > 0:15:38and still haven't seen a single one.
0:15:38 > 0:15:42We have seen some wonderful wildlife around here
0:15:42 > 0:15:45but we're all beginning to get a little bit sick
0:15:45 > 0:15:48of just staring out at this lake and seeing nothing!
0:15:48 > 0:15:51Problem is the burrows are usually quite deep
0:15:51 > 0:15:54and could be anywhere along here.
0:15:54 > 0:15:57That's where they're spending the majority of the day,
0:15:57 > 0:16:01but they usually spend about 10 or 11 hours every day
0:16:01 > 0:16:03out searching for food
0:16:03 > 0:16:06so it's pretty amazing we haven't seen one yet.
0:16:06 > 0:16:10Just hope that if they do come out feeding, it's quite soon.
0:16:10 > 0:16:13But just because we can't find any,
0:16:13 > 0:16:16that doesn't mean you don't get to see one.
0:16:16 > 0:16:19Here's a platypus in action.
0:16:20 > 0:16:24They may look cute, but if you were an insect or a crustacean
0:16:24 > 0:16:29living in a stream, then this would be your worst nightmare. Trust me!
0:16:29 > 0:16:34The platypus is so good at hunting it even does it with its eyes shut.
0:16:34 > 0:16:39But that's not because it's trying to give its lunch a sporting chance,
0:16:39 > 0:16:40it just doesn't need them.
0:16:41 > 0:16:45Underwater, it's bill can detect the tiny electrical pulses given off
0:16:45 > 0:16:48if a crayfish so much as twitches a muscle.
0:16:48 > 0:16:52Imagine that, you're a crayfish hiding under a rock
0:16:52 > 0:16:55and you just twitch once and you're a goner.
0:16:55 > 0:16:59So the beaver-tailed, rat-bodied, swan-footed, electro-sensing
0:16:59 > 0:17:03duck-billed platypus is a truly weird and wonderful predator
0:17:03 > 0:17:08that also just happens to be almost impossible to find.
0:17:08 > 0:17:11Still, I'm glad we tried.
0:17:14 > 0:17:16The duck-billed platypus.
0:17:16 > 0:17:18With its electro-super sense
0:17:18 > 0:17:21it can catch a crayfish with its eyes closed,
0:17:21 > 0:17:24and it's one of the only venomous mammals in the whole world.
0:17:24 > 0:17:27Definitely weird, definitely on the Deadly 60.
0:17:30 > 0:17:32OK, so I know we didn't find one.
0:17:32 > 0:17:35But it's one of the only venomous mammals in the world,
0:17:35 > 0:17:40and the duck-billed platypus has got to be on the Deadly 60.
0:17:46 > 0:17:48We've been here for a couple of days now
0:17:48 > 0:17:51and no sign whatsoever of a platypus.
0:17:51 > 0:17:54They are very shy and secretive creatures.
0:17:54 > 0:17:58But we're starting to wonder if there really are any here at all.
0:17:58 > 0:18:00Think it's just a question of waiting.
0:18:02 > 0:18:04Just waiting.
0:18:14 > 0:18:18If you ask any naturalist working out in the field
0:18:18 > 0:18:21which animal causes them the most strife,
0:18:21 > 0:18:24they won't say snakes or spiders or scorpions,
0:18:24 > 0:18:25they'll say ants.
0:18:25 > 0:18:27I know that seems ridiculous,
0:18:27 > 0:18:30I mean, back home in the UK, all an ant really does is
0:18:30 > 0:18:32perhaps spoil a picnic for you.
0:18:32 > 0:18:36But there are many places around the world where that isn't the case.
0:18:36 > 0:18:38Here in Australia, is one of them.
0:18:38 > 0:18:39I'll show you why.
0:18:39 > 0:18:42There's a little hole here,
0:18:42 > 0:18:46and I'll see if I can bring out the ant that lives inside.
0:18:48 > 0:18:51Usually just a bit of vibration is enough to bring them out.
0:18:51 > 0:18:52Ah, here we go.
0:18:52 > 0:18:54Got one coming out.
0:18:54 > 0:18:59This is a jumping jack ant.
0:18:59 > 0:19:04It's got absolutely huge mandibles.
0:19:05 > 0:19:08Very, very aggressive, these little ants.
0:19:08 > 0:19:11But the dangerous thing about them isn't their bite,
0:19:11 > 0:19:13it's their sting.
0:19:13 > 0:19:16Ants are in the same insect group as bees and wasps,
0:19:16 > 0:19:19and like them, a lot of their venoms have stuff in them
0:19:19 > 0:19:21that people are very, very allergic to.
0:19:21 > 0:19:25Here in Australia, people actually die from bites from these ants.
0:19:30 > 0:19:33These ones here are all in defence of their colony.
0:19:33 > 0:19:35I've got two of them now
0:19:35 > 0:19:36coming right for me.
0:19:36 > 0:19:37Look at this one!
0:19:39 > 0:19:41They are like little bulldogs.
0:19:41 > 0:19:44This one's savaging the front of the camera, look!
0:19:44 > 0:19:45Look at that!
0:19:47 > 0:19:48They're totally fearless...
0:19:51 > 0:19:55..and they really have got an attitude way beyond their size.
0:19:56 > 0:19:59Apart from anything else, they'll jump
0:19:59 > 0:20:01after what they see as being a threat to their colony.
0:20:03 > 0:20:05Look at that! He's stinging the lens!
0:20:05 > 0:20:07Getting right stuck into it!
0:20:07 > 0:20:08Look at that!
0:20:08 > 0:20:11I'm glad that isn't my finger.
0:20:12 > 0:20:14Look at this one. He's coming after me.
0:20:14 > 0:20:18That doesn't matter that the camera is many times his own size,
0:20:18 > 0:20:20totally fearless.
0:20:25 > 0:20:26Wow!
0:20:27 > 0:20:29Ooh! That one jumped!
0:20:29 > 0:20:31That one just made a big jump, right at the lens.
0:20:31 > 0:20:32How cool is that?!
0:20:32 > 0:20:35It just keeps leaping at me.
0:20:35 > 0:20:38It's like a little insect rottweiler.
0:20:38 > 0:20:40Look at that! Look!
0:20:40 > 0:20:43It just sticks its jaws open and just goes, "I'm 'aving ya!"
0:20:43 > 0:20:46And just makes a big leap at the lens.
0:20:46 > 0:20:47Just brilliant.
0:20:47 > 0:20:51I don't think I've ever seen a creature quite so aggressive.
0:20:53 > 0:20:55Jumping jack ants.
0:20:55 > 0:20:56Definitely deadly.
0:21:01 > 0:21:02The jumping jack ant.
0:21:02 > 0:21:06One of the world's most venomous, and truly dangerous ants.
0:21:06 > 0:21:09A really fiery, feisty customer,
0:21:09 > 0:21:12that definitely deserves to go on the Deadly 60.
0:21:23 > 0:21:25The next animal I'm hoping to find
0:21:25 > 0:21:29is probably the closest thing in the natural world to an alien spaceship.
0:21:29 > 0:21:31I'm not really that worried about finding them
0:21:31 > 0:21:34because this time of year, for just a couple of months,
0:21:34 > 0:21:37tens of even hundreds of thousands gather in these seas
0:21:37 > 0:21:38to mate and breed.
0:21:43 > 0:21:45At first, I could only see rocks and weed.
0:21:45 > 0:21:49But then, odd shapes caught my eye
0:21:49 > 0:21:53and I got the distinct feeling I was being watched.
0:21:56 > 0:22:00It may only be metres from the beach, but I was entering into
0:22:00 > 0:22:01a completely alien world.
0:22:01 > 0:22:06And the aliens in question are giant cuttlefish.
0:22:31 > 0:22:35This really is one of the most remarkable scenes on the planet.
0:22:36 > 0:22:41There are giant cuttlefish absolutely everywhere.
0:22:41 > 0:22:45I mean, you can't move without seeing 30 or 40 of them,
0:22:45 > 0:22:48I think, actually, one's slithering on my leg!
0:22:51 > 0:22:57The giant cuttlefish is almost like an underwater chameleon.
0:22:58 > 0:23:01They can change their colours through camouflage
0:23:01 > 0:23:04to match their background.
0:23:04 > 0:23:06But also, they can do it to describe their mood.
0:23:06 > 0:23:08Just like a chameleon can.
0:23:09 > 0:23:14It's a way of saying, "I'm big, I'm vibrant, I'm bright.
0:23:15 > 0:23:18"You don't want to mess with me!"
0:23:21 > 0:23:24This is what we've been looking for.
0:23:26 > 0:23:27Two males fighting.
0:23:27 > 0:23:30Displaying against each other.
0:23:32 > 0:23:35You see, the larger one's blocking itself out...
0:23:37 > 0:23:39..and the smaller one seems to have moved away,
0:23:39 > 0:23:42to have decided that it's got too much on its hands
0:23:42 > 0:23:44to take this big one on.
0:23:44 > 0:23:46Look at the colour display there!
0:23:47 > 0:23:50This is amazing!
0:23:51 > 0:23:56If a fight gets serious, things get way out of hand.
0:23:56 > 0:23:58This is when you see the dark side of the cuttlefish.
0:23:58 > 0:24:01There are no rules when these boys fight.
0:24:01 > 0:24:04And they can seriously damage one another.
0:24:08 > 0:24:11That is a SERIOUS colour display!
0:24:16 > 0:24:18What I've never seen before
0:24:18 > 0:24:20is that they can take their mantle -
0:24:20 > 0:24:23what looks like the outside of their back -
0:24:24 > 0:24:27and they can kind of flicker it up,
0:24:28 > 0:24:30creating these ridges that run all the way
0:24:30 > 0:24:32down the back of their shell.
0:24:35 > 0:24:38Well, I did tell you there were gonna be
0:24:38 > 0:24:40some surprising animals on this show!
0:24:40 > 0:24:42And you don't get much more surprising
0:24:42 > 0:24:44than the giant cuttlefish!
0:24:52 > 0:24:55This genuinely is one of the weirdest creatures in the sea.
0:24:59 > 0:25:02But it also is a devastating predator.
0:25:06 > 0:25:11These incredible hunters deploy a range of deadly weapons and tactics.
0:25:11 > 0:25:15Their eyes are among the most highly developed in the animal kingdom.
0:25:15 > 0:25:18Cuttlefish can detect polarised light,
0:25:18 > 0:25:21allowing them to detect the smallest of movements,
0:25:21 > 0:25:23even in the dark waters of the ocean.
0:25:26 > 0:25:28Once they're locked on,
0:25:28 > 0:25:31the cuttlefish deploys its next deadly tactic.
0:25:34 > 0:25:36They're masters of disguise,
0:25:36 > 0:25:38literally changing shape and colour
0:25:38 > 0:25:41to creep up on their unsuspecting prey.
0:25:48 > 0:25:51This sneaky cuttlefish has changed itself
0:25:51 > 0:25:53to look like a piece of floating weed
0:25:53 > 0:25:56that floats slowly along the ocean floor.
0:26:06 > 0:26:08Then once it's close enough
0:26:08 > 0:26:11the cuttlefish engages its next deadly weapon.
0:26:12 > 0:26:15Two long, lightning-fast tentacles
0:26:15 > 0:26:17that smash into their prey.
0:26:26 > 0:26:29On the end of those super-quick tentacles
0:26:29 > 0:26:33are strong suckers that snare the victim,
0:26:33 > 0:26:34meaning there's no escape.
0:26:37 > 0:26:42Even an armoured crab is no match for the cuttlefish's deadly strike.
0:26:51 > 0:26:53THAT was quite something!
0:26:55 > 0:26:58They've got the fastest colour change in the animal kingdom
0:26:58 > 0:27:02and a strike that could smash a crab into pieces.
0:27:03 > 0:27:06The giant cuttlefish is on the Deadly 60.
0:27:09 > 0:27:11It's the chameleon of the seas,
0:27:11 > 0:27:13with lightning-fast colour change,
0:27:13 > 0:27:16and striking like a missile.
0:27:16 > 0:27:19The giant cuttlefish is on the Deadly 60.
0:27:24 > 0:27:25Next time on the Deadly 60...
0:27:25 > 0:27:27Just keep your arms up!
0:27:29 > 0:27:30Whoa! Urgh!
0:27:30 > 0:27:32(This place is spook central!)
0:27:45 > 0:27:48Subtitles by Red Bee Media Ltd
0:27:48 > 0:27:52E-mail subtitling@bbc.co.uk