0:00:02 > 0:00:06Australia, home of surfer dudes, strange lingo, "Fair dinkum!",
0:00:06 > 0:00:08sunshine and the Barrier Reef.
0:00:08 > 0:00:12It's the world's biggest, most spectacular coral reef.
0:00:12 > 0:00:15And every creature is linked to another.
0:00:15 > 0:00:18A huge family tree dating back 18 million years.
0:00:18 > 0:00:22From the miniscule to the mammoth to the miraculous,
0:00:22 > 0:00:25they're all connected in Barney's Barrier Reef!
0:00:48 > 0:00:51Are you sure about eating all that?
0:00:51 > 0:00:53Why?
0:00:53 > 0:00:55Have you forgotten what the show's about?
0:00:55 > 0:00:59- Why are you dressed like that? - We need to be prepared,
0:00:59 > 0:01:03and that includes having a very strong stomach.
0:01:03 > 0:01:04What is it about?
0:01:08 > 0:01:10Slime...
0:01:11 > 0:01:13..snot...
0:01:13 > 0:01:16and guts.
0:01:18 > 0:01:21Yeah, I'm not hungry any more.
0:01:21 > 0:01:23What, slime, snot AND guts?
0:01:23 > 0:01:28- Do we have to have all three at once?- Yeah! They're all connected!
0:01:28 > 0:01:31So, here is your slime prevention suit.
0:01:31 > 0:01:35You'll need it, because it's time for slime, snot and guts.
0:01:35 > 0:01:36Cool.
0:01:43 > 0:01:46So, in our world, slime is pretty gross.
0:01:46 > 0:01:49Yeah, as is snot and guts. Ew.
0:01:49 > 0:01:53But in the fish world, they're used much more imaginatively.
0:01:53 > 0:01:55They're crucial for survival.
0:01:55 > 0:01:59It helps them move, eat, sleep and even protect themselves.
0:01:59 > 0:02:03- He's SNOT kidding!- No.
0:02:05 > 0:02:09Guess the name of this next fish. I bet you won't get it.
0:02:09 > 0:02:10Er, pink wobble fish?
0:02:10 > 0:02:13- No.- Rocking pink fish?
0:02:13 > 0:02:15No, I'll give you a clue.
0:02:15 > 0:02:17ROARS
0:02:17 > 0:02:19Ah! Rhinoceros fish!
0:02:19 > 0:02:23Aw! So close! This, in fact, is called the rhinopias fish.
0:02:23 > 0:02:25I can see the resemblance now.
0:02:25 > 0:02:29Although I've never seen a pink rhinoceros.
0:02:29 > 0:02:33Yeah, that's down to his pinky, super slimy rhinopias skin.
0:02:33 > 0:02:36Ah, so he looks and feels like a pink blancmange.
0:02:39 > 0:02:44Yeah, rhinopias, like almost all other fish, produce their own snot,
0:02:44 > 0:02:46which they use to coat their skin.
0:02:47 > 0:02:50Ew! Gross! So, they make their own snot coat.
0:02:50 > 0:02:53Yeah, it's like a layer of slimy snot
0:02:53 > 0:02:56that moves from the head to the fins to the tail.
0:02:56 > 0:02:58Why do they do that?
0:02:58 > 0:03:02Let me explain. The principal function of fish mucus
0:03:02 > 0:03:05is to remove parasites and dirt from the skin.
0:03:05 > 0:03:08Cool. So it's like a snot bath gel, Dr Barnacles.
0:03:08 > 0:03:13Confirmed, It also helps the fish glide smoothly through the water.
0:03:13 > 0:03:17OK, so our snotty rhinopias comes complete with a slimy mucus coat
0:03:17 > 0:03:23to help him move, keep him clean and free from infection. Next!
0:03:27 > 0:03:31Ah, little baby fish.
0:03:31 > 0:03:34They're actually spiny chromis babies.
0:03:34 > 0:03:36They're a species of damselfish.
0:03:36 > 0:03:39- Am not!- Aw, I think they're cute.
0:03:39 > 0:03:42Why don't get lost or blown away?
0:03:42 > 0:03:44Mummy and Daddy keep an eye on them.
0:03:44 > 0:03:48"Stay together. Stop messing around. Oi, you, come here!"
0:03:48 > 0:03:52It's good to know parents nag kids in the ocean too.
0:03:52 > 0:03:55Yeah, these parents are very dedicated,
0:03:55 > 0:03:58but this isn't every kid's idea of good parenting.
0:03:58 > 0:04:02- Oh, yes?- Hmm, damselfish produce mucus on their scales
0:04:02 > 0:04:06which their babies then nibble on.
0:04:06 > 0:04:09- Oh, no!- Eww. So they feed off their parents' snot?
0:04:09 > 0:04:13Yeah, it's a snot buffet for these little tiddlers.
0:04:14 > 0:04:16- Yummy!- Gross! I mean,
0:04:16 > 0:04:21I don't always like my mum's dinners, but that's one meal I would not eat.
0:04:21 > 0:04:24Hmmm. Which reminds me of my favourite joke.
0:04:24 > 0:04:28What's the difference between bogies and broccoli?
0:04:28 > 0:04:29I don't know.
0:04:29 > 0:04:32Children won't eat broccoli!
0:04:36 > 0:04:38The rhinopias fish and the spiny chromis
0:04:38 > 0:04:42both have ingenious uses for their snot coats.
0:04:42 > 0:04:45So, the connection is snot jackets.
0:04:50 > 0:04:53They're happy little chappies. Who are they?
0:04:53 > 0:04:57Meet the cleaner wrasse, letting their customers know
0:04:57 > 0:04:59they're ready for work.
0:04:59 > 0:05:01Hello! Anyone want a snot wash?!
0:05:01 > 0:05:04Ew, a snot wash?! You know what?
0:05:04 > 0:05:08These ocean dudes are a bit snot obsessed, if you ask me.
0:05:08 > 0:05:09Hey!
0:05:09 > 0:05:14As we've found out mucus helps protect fish and keep them clean,
0:05:14 > 0:05:19but it must taste pretty good too, as these have a real taste for it.
0:05:20 > 0:05:21How do you mean?
0:05:21 > 0:05:25They spend their whole day nibbling on other fish.
0:05:25 > 0:05:30It's an I'll scratch your back and you scratch mine relationship.
0:05:35 > 0:05:38The fish line up for their daily scrub
0:05:38 > 0:05:41and the cleaner wrasse get to feast on yummy snot.
0:05:41 > 0:05:44But why would they want to eat that?
0:05:44 > 0:05:47Because, in the snot are the gnathiid isopods.
0:05:47 > 0:05:51Otherwise known as deadly parasites.
0:05:53 > 0:05:56They can make the fish really, really ill.
0:05:56 > 0:05:59When the super hero wrasses eat the mucus,
0:05:59 > 0:06:03they eat the isopods from their fishy client scales,
0:06:03 > 0:06:07leaving them germ free until the next evil parasite attack.
0:06:11 > 0:06:13And they don't hang about.
0:06:13 > 0:06:17Your average wrasse can eat more than 1,000 isopods in a day.
0:06:17 > 0:06:23- And, all the snot that goes along with it.- Well, that's a lot of snot.
0:06:23 > 0:06:28Like the spiny chromis, it seems that snot is quite a healthy meal
0:06:28 > 0:06:30for reef residents like the wrasse.
0:06:30 > 0:06:33The connection is mucus eating. Eww.
0:06:33 > 0:06:35Any more snotty contenders?
0:06:40 > 0:06:44This is fun, peek-a-boo!
0:06:45 > 0:06:48Show me someone who doesn't love a clownfish.
0:06:50 > 0:06:53Aw, they're so cute. So nice to see them playing.
0:06:53 > 0:06:58They look like they're having fun, but they're rubbing themselves
0:06:58 > 0:07:02against the anemone to coat themselves in the anemone's mucus.
0:07:02 > 0:07:06- Ooh, that feels better. - Lovely slime!
0:07:06 > 0:07:08Why would they want to do that?
0:07:09 > 0:07:14Anemones sting, but their mucus protects clownfish from being stung,
0:07:14 > 0:07:19which means they can hang out and bounce around without any worries.
0:07:19 > 0:07:22Ah, it's another symbiotic relationship.
0:07:22 > 0:07:26Yep. And it means the bigger fish who might want to gobble them up
0:07:26 > 0:07:28can't go near them.
0:07:28 > 0:07:31- What?!- Why is one fish bigger than the other?
0:07:31 > 0:07:36Well, the bigger one is the girl and the small one is the boy.
0:07:36 > 0:07:39The clownfish is yet another mucus addict.
0:07:39 > 0:07:41At least they're not eating it.
0:07:41 > 0:07:45Their love of snot links them to the cleaner wrasse
0:07:45 > 0:07:47as both use it for their own benefit.
0:07:51 > 0:07:53Pretty Polly, pretty Polly.
0:07:53 > 0:07:55Polly want a cracker.
0:07:55 > 0:08:00The parrotfish, by day, reef rock chompers.
0:08:00 > 0:08:03By night, serene snot sleepers.
0:08:08 > 0:08:12- Snot sleepers?- Yep. See the cocoon surrounding him?- Yeah.
0:08:12 > 0:08:17That's the parrotfish's very own deluxe, snot sleeping bag.
0:08:17 > 0:08:20- It looks more like a cobweb. - No, it's snot all right.
0:08:20 > 0:08:23This is their for the night.
0:08:23 > 0:08:25Once they've found a little space
0:08:25 > 0:08:29they produce their very own mucus sleeping bag
0:08:29 > 0:08:30and camp out for the night.
0:08:33 > 0:08:36They get left alone because the sleeping-bag
0:08:36 > 0:08:40- conceals their smell and tastes yucky.- Oh, no!
0:08:40 > 0:08:43But, you haven't heard the best bit.
0:08:43 > 0:08:47When they get up, they have to eat their way out.
0:08:47 > 0:08:49What, they eat their own snot?!
0:08:49 > 0:08:53Ew, they don't let anything go to waste in this ocean world!
0:08:53 > 0:08:56Who'd have thought snot could be so useful?
0:08:56 > 0:09:01Not everyone's idea of a comfy bed, but it's certainly different.
0:09:01 > 0:09:05Clownfish and parrotfish uses mucus to defend themselves.
0:09:05 > 0:09:09Clownfish cover themselves in the anemone's mucus
0:09:09 > 0:09:13so they don't get stung and the parrotfish surround themselves in it
0:09:13 > 0:09:15to get a good night's kip.
0:09:15 > 0:09:18They both use snot to protect themselves.
0:09:21 > 0:09:24- What are you doing? - I'm having a bogey! Boogie!
0:09:24 > 0:09:28A bogey boogie! Get it?! Join in!
0:09:32 > 0:09:35Moving on! Reef-Cap time!
0:09:36 > 0:09:39We've slithered from the rocky rhinopias
0:09:39 > 0:09:44to the snot-guzzling parrotfish. How are they all connected?
0:09:44 > 0:09:46Our snot-covered pinky rhinopias fish
0:09:46 > 0:09:49was linked to the baby spiny chromis,
0:09:49 > 0:09:52- who eat snot off their parents' bodies.- Yuck!
0:09:52 > 0:09:55At least it's mucus from a relative.
0:09:55 > 0:09:59Cleaner wrasse eat snot off the bodies of lots of different fish.
0:09:59 > 0:10:04Clownfish bathe in anemone mucus to live in their tentacles sting free.
0:10:04 > 0:10:06- Yeeha!- Clever, but not as clever as
0:10:06 > 0:10:10making your own snot sleeping bag to keep away enemies.
0:10:10 > 0:10:14- Then eating it to get out. - Waste snot, want not!- Gross!
0:10:14 > 0:10:17- Here's our next slime addict. - Ew! Ew!
0:10:26 > 0:10:30This means we're entering severe venomous animal territory.
0:10:30 > 0:10:33Oh, yes. We're on venom high alert, Gem.
0:10:37 > 0:10:40Meet the blue ringed octopus.
0:10:40 > 0:10:44Those flashing blue rings mean he's either threatened...
0:10:46 > 0:10:48..or excited.
0:10:48 > 0:10:51There's a crab! Dinner-time! Yum!
0:10:51 > 0:10:54He has his own in-built warning system.
0:10:54 > 0:10:58Yeah. And for a very good reason. This is no ordinary octopus.
0:10:58 > 0:11:02Firstly, he uses saliva to kill his prey.
0:11:02 > 0:11:04How can you kill with spit?
0:11:04 > 0:11:06When your spit is venomous.
0:11:06 > 0:11:11It's powerful enough to knock down 26 humans within minutes.
0:11:11 > 0:11:13Woah!
0:11:13 > 0:11:15Calling Dr Barnacles!
0:11:15 > 0:11:19Well, the octopus has two deadly toxins in its saliva.
0:11:19 > 0:11:23One to kill its favourite dinner-time snack, crabs.
0:11:23 > 0:11:26Uh-oh, useless pincers!
0:11:26 > 0:11:30And the other is used against predators like eels as defence.
0:11:30 > 0:11:35The toxic spit paralyses the crab allowing the octopus to munch away
0:11:35 > 0:11:36while it's still alive.
0:11:36 > 0:11:38Oh, man!
0:11:41 > 0:11:44So he's like an underwater James Bond villain!
0:11:48 > 0:11:52The parrotfish produces a snot sleeping bag that tastes
0:11:52 > 0:11:57disgusting and the octopus has disgustingly dangerous spit.
0:11:57 > 0:12:00Urgh, toxic spit! That's cool.
0:12:00 > 0:12:04The parrotfish and the blue ringed octopus are linked
0:12:04 > 0:12:07because of their toxic spit.
0:12:10 > 0:12:12Let's do the crab dance.
0:12:12 > 0:12:15- # Hands in the air - Like you have leg hair
0:12:15 > 0:12:20- # Juggle and lift - For the water to shift
0:12:20 > 0:12:24- # Scratch and lift - And wave...to Dave!
0:12:29 > 0:12:31# Hands out, hands together
0:12:31 > 0:12:33# Ooh, er, look at the weather! #
0:12:44 > 0:12:47Phew, now that was tiring. Where were we?
0:12:47 > 0:12:50We're about to find out if the porcelain crab
0:12:50 > 0:12:52prefers slime, snot or guts.
0:12:52 > 0:12:54He's a snot fiend, this one.
0:12:56 > 0:13:00Not only are his hands covered in it, he also covers himself in
0:13:00 > 0:13:03anemone mucus, like the clownfish.
0:13:04 > 0:13:08So, he too can hang out in the anemone's tentacles.
0:13:08 > 0:13:10Oh, this is comfy.
0:13:11 > 0:13:14See how his hands are like combs.
0:13:14 > 0:13:18These are covered in mucus which allows him to comb through the water
0:13:18 > 0:13:23for food which stick to his snotty hands which he feeds into his mouth.
0:13:25 > 0:13:28How cool! Hands that you can stick food to.
0:13:28 > 0:13:31- Now that would be fun. And convenient.- Thanks.
0:13:31 > 0:13:34Like the blue ringed octopus, the porcelain crab
0:13:34 > 0:13:36uses slimy stuff to feed.
0:13:36 > 0:13:40But while the blue ringed octopus has poisonous spit,
0:13:40 > 0:13:44the porcelain crab uses harmless snot to stick food to his claws.
0:13:44 > 0:13:47The moral is, if he hands you a sandwich,
0:13:47 > 0:13:51don't eat it, it's got snot on it. Next, please!
0:13:52 > 0:13:55Why have I got a feather duster in my hand?
0:13:55 > 0:13:59It's a clue to our next animal, but whilst you're there...
0:13:59 > 0:14:01Oh, yeah! Clean up whilst you're there,
0:14:01 > 0:14:05but it's a clue to the next animals. I know your game is!
0:14:09 > 0:14:14Aw, the little feather duster worms, they're so cute.
0:14:16 > 0:14:22What?! No, they're worms, Gem, and as we all know, worms are not cute.
0:14:22 > 0:14:24These worms are cool.
0:14:27 > 0:14:30Yeah, but they're still part of the worm family.
0:14:30 > 0:14:35- Related to those slimy brown ones in the soil.- Hold on! One minute!
0:14:36 > 0:14:41- I won't tolerate worm discrimination. Worms get a very bad press.- Oh, no!
0:14:41 > 0:14:45With people like you going, ew, they're slimy and dirty!
0:14:45 > 0:14:49But, for the record, worms were here long before us
0:14:49 > 0:14:54- and they have some really important jobs to do.- OK! Woah!
0:14:54 > 0:14:58Didn't know you felt so passionately about worms.
0:14:58 > 0:15:02Well, it's unfair. They're great recyclers as compost worms,
0:15:02 > 0:15:04and these guys are no different.
0:15:06 > 0:15:10Feather duster worms are like filter feeders,
0:15:10 > 0:15:14using their feathery hands or radials as they're officially called,
0:15:14 > 0:15:17to pick up food and other bits from the water.
0:15:18 > 0:15:22What good does that do, Mrs over-reacting worm campaigner?
0:15:22 > 0:15:26It helps keep water clean and pollution-free.
0:15:30 > 0:15:35Where's the slime factor? Or do you just like them cos they're pretty?!
0:15:35 > 0:15:39No! They live in a tube made from a kind of snot cement.
0:15:39 > 0:15:42It's mucus and sand mixed together.
0:15:42 > 0:15:45The slime is also on their feathery hands.
0:15:45 > 0:15:49When it filter the water for particles, bits go into its mouth
0:15:49 > 0:15:53- and some are used to build the tube it lives in.- A snot, tube home.
0:15:53 > 0:15:55Yep. Worms are quite ingenious.
0:15:55 > 0:16:00I wouldn't go that far. But they are pretty cool with their sticky hands.
0:16:00 > 0:16:04I wonder if he stole that idea from the porcelain crab?!
0:16:04 > 0:16:08Like the porcelain crab, the feather duster worm
0:16:08 > 0:16:11uses its mucus-covered feathery nets to feed.
0:16:11 > 0:16:14Can there be any more uses left for snot, I wonder?
0:16:14 > 0:16:16You ain't seen nothing yet!
0:16:22 > 0:16:26Don't ever ask a sea cucumber to do anything urgent.
0:16:26 > 0:16:31- They travel at the speed of seven and a half inches per hour.- Huh?!
0:16:31 > 0:16:34And you had the cheek to have a go at worms!
0:16:34 > 0:16:38Hang on! I didn't say they weren't talented, Gem!
0:16:39 > 0:16:43I'd now like to demonstrate how a sea cucumber eats.
0:16:52 > 0:16:56The things I do for this show. The sea cucumber is one slimy geezer.
0:16:56 > 0:17:01His feet are sticky. Combine that with the fact he eats sand
0:17:01 > 0:17:04and you have the easiest eating in the ocean.
0:17:04 > 0:17:09There's got to be more to it than that. Even for a sea cucumber!
0:17:09 > 0:17:13It's not difficult to eat sand when you're travelling on it.
0:17:13 > 0:17:16It has several ways of sticky feeding.
0:17:16 > 0:17:20Some of its tentacles scoop up sand. Some are covered in mucus,
0:17:20 > 0:17:24the sand sticks to them, but this is helped by the fact
0:17:24 > 0:17:28that the sea cucumber produces loads of snot. The sand sticks on easily.
0:17:28 > 0:17:32Eww. So they look slimy and snotty.
0:17:32 > 0:17:37For your information, they serve a very important purpose in the reef.
0:17:37 > 0:17:42By gnoshing up the sand, they filter the sand and keep the reef clean.
0:17:45 > 0:17:49The problem is, when they vacuum up that much sand,
0:17:49 > 0:17:52well, what goes in, must come out.
0:17:52 > 0:17:54- Somehow.- Ew, Barney.
0:17:54 > 0:17:57There's more! For his next trick,
0:17:57 > 0:18:00he'll spew copious amounts of sticky white gunge.
0:18:00 > 0:18:04- Dare I ask where that's coming from? - Haha, his bum.
0:18:04 > 0:18:07Nothing would surprise me. With a sea SPEWcumber.
0:18:07 > 0:18:10Those are called Cuvierian tubules.
0:18:10 > 0:18:15They're stored in the cucumber's bottom as a defence mechanism.
0:18:15 > 0:18:20So when he's scared or angry, he releases his very own silly string?!
0:18:20 > 0:18:25Yeah! Extremely sticky and smelly string that entangles his predators
0:18:25 > 0:18:27and allow the cucumber to escape.
0:18:27 > 0:18:32A snot-covered body and slimy silly strings spewing,
0:18:32 > 0:18:34is there no end to his talents?!
0:18:34 > 0:18:36Apparently not!
0:18:36 > 0:18:38So, the sea cucumber's sticky body
0:18:38 > 0:18:42links him to the feather duster worms with their mucus tubes.
0:18:42 > 0:18:45And they're linked by slimy body suits.
0:18:45 > 0:18:50Enough of your sea cucumber obsession, it's time for a Reef-Cap.
0:18:56 > 0:19:01You don't have to go far to find slime, snot or guts in the ocean.
0:19:01 > 0:19:05I thought you couldn't beat a snot sleeping bag, but I was so wrong!
0:19:05 > 0:19:09The blue ringed octopus so outgrosses the parrotfish
0:19:09 > 0:19:11with its deadly toxic saliva.
0:19:11 > 0:19:14Luckily, the porcelain crab is not fierce at all.
0:19:14 > 0:19:18He likes to boogie with his bogey. It's bogey boogie.
0:19:18 > 0:19:22The feather duster worm is just like a feather duster,
0:19:22 > 0:19:24but has a slimy feeding fan.
0:19:24 > 0:19:28But for one big snot fest, you only have to look at the sea cucumber.
0:19:28 > 0:19:30He's sticky all over.
0:19:30 > 0:19:34So, are you ready for more slime, snot and guts, Gem?
0:19:34 > 0:19:36Ooh! Bring it on!
0:19:36 > 0:19:38OK!
0:19:45 > 0:19:47Who's this cute looking...thing?
0:19:47 > 0:19:49I shall give you a clue, Sherlock.
0:19:51 > 0:19:53A hare? It looks nothing like one.
0:19:53 > 0:19:58I know, but it's called that because its ears stick up like a hare.
0:19:58 > 0:20:02It's related to other slimy wonders like snails and clams.
0:20:02 > 0:20:06Aw, just looks like a cute alien to me.
0:20:06 > 0:20:11Well, he may look cute, but he has two rather odd slimy skills.
0:20:11 > 0:20:13Uh-oh!
0:20:21 > 0:20:25He may look like he's innocently sliding along the ocean,
0:20:25 > 0:20:27but look closely, and...
0:20:27 > 0:20:28Wa-hey! Look at that!
0:20:28 > 0:20:30That is his poo cannon.
0:20:32 > 0:20:36- Poo cannon?!- He ejects his poo from his hole on his back.
0:20:36 > 0:20:41He fires out pellets the size of raisins a few times every minute.
0:20:41 > 0:20:42That's not all.
0:20:42 > 0:20:46Here it is innocently trotting along the sea floor.
0:20:46 > 0:20:49Gnoshing on grass and algae, and voila!
0:20:50 > 0:20:54Woah! He's disappeared in a puff of purple smoke.
0:20:54 > 0:20:56He's still there for the moment.
0:20:56 > 0:20:59This distracts his enemies and allows him to escape
0:20:59 > 0:21:03- from any creatures eyeing him up for dinner.- Where has he gone?
0:21:03 > 0:21:05Wow! Now, that is cool!
0:21:05 > 0:21:09So, this slimy but cute alien isn't what he seems.
0:21:09 > 0:21:12He can fire poo at random and release stinky ink.
0:21:15 > 0:21:18His slimy gut antics link him to the sea cucumber
0:21:18 > 0:21:21with his silly string spewing bottom.
0:21:25 > 0:21:28Woah, watch out, mate, there's a cliff! Oh!
0:21:28 > 0:21:31He's a bit clumsy. Don't these Aussie sea stars
0:21:31 > 0:21:34have a million, zillion feet or something?
0:21:38 > 0:21:42You'd think he'd have enough to stop him falling.
0:21:42 > 0:21:45Not quite a zillion, Barney, more like 20 legs.
0:21:45 > 0:21:48But, they have thousands of feet, so yes,
0:21:48 > 0:21:51you'd think they'd be able to walk straight.
0:21:52 > 0:21:55Crown-of-thorn sea stars are predators.
0:21:55 > 0:22:00They have deadly poisonous spines and they move by pumping water
0:22:00 > 0:22:04in and out of many tube like feet. They get together in large groups
0:22:04 > 0:22:07and declare war on their favourite corals.
0:22:12 > 0:22:14Sea stars go to war! Oh, yeah!
0:22:14 > 0:22:18They're not given thousands of feet for nothing.
0:22:18 > 0:22:22They feed on coral colonies where they grip on with their suction caps.
0:22:22 > 0:22:26Imagine being covered by a giant suckered bath mat.
0:22:26 > 0:22:29In the centre of their underbelly is a mouth,
0:22:29 > 0:22:33- and inside that is their stomach. - Hold the phone.
0:22:33 > 0:22:35I suggest you put a hold on that cereal.
0:22:37 > 0:22:39When they find a tasty coral,
0:22:39 > 0:22:43they force their stomachs out through their mouths
0:22:43 > 0:22:46and eat the coral straight off its skeleton.
0:22:49 > 0:22:51Er, I'm not so hungry any more.
0:22:51 > 0:22:54Are you telling me they spew their guts
0:22:54 > 0:22:58and eat their food before they put it in their mouth?
0:22:58 > 0:23:00Yeah, that's freaky all right.
0:23:00 > 0:23:03All of this from an animal with no brain.
0:23:03 > 0:23:05- Huh?!- His gut-spewing antics
0:23:05 > 0:23:09link him to the sea hare with his slimy purple ink bombs.
0:23:09 > 0:23:11Connected by slimy juices, nice!
0:23:11 > 0:23:15We've had loads of slime and snot and some really gross guts.
0:23:15 > 0:23:17Whatever next?
0:23:19 > 0:23:20Ole!
0:23:22 > 0:23:26Meet the nudibranch or as they're also known, naked slugs.
0:23:26 > 0:23:29I've never seen a slug as colourful as this before.
0:23:29 > 0:23:32These are...dur, dur, dur...
0:23:32 > 0:23:33flesh-eating slugs.
0:23:35 > 0:23:40Don't be ridiculous, Barney. Slugs don't eat flesh. Do they?!
0:23:43 > 0:23:45Don't worry, they don't touch humans.
0:23:45 > 0:23:50But they like animals that sting, like jelly fish, anemone, corals
0:23:50 > 0:23:55and they absorb bits of the creature they've for their own self defence.
0:23:55 > 0:23:59- OK. Dr Barnacles, can you explain? - Of course I can.
0:23:59 > 0:24:01If they'd gulped down a sea anemone,
0:24:01 > 0:24:06they could use the sting of that anemone to protect themselves.
0:24:06 > 0:24:10Or they can borrow toxins from other animals like sponges.
0:24:10 > 0:24:12All of this goes into their slimy coat.
0:24:12 > 0:24:15It makes them taste really bad.
0:24:15 > 0:24:19Yuck! Despite looking pretty they have a poisonous, mucus coat.
0:24:19 > 0:24:24- Yes. One nick is usually enough to put a predator off.- Oh, no!
0:24:24 > 0:24:28- The mucus doesn't just taste bad, does it?- No, That's right.
0:24:28 > 0:24:30When they get stressed,
0:24:30 > 0:24:34they can produce the poisonous snot which is deadly to other animals.
0:24:34 > 0:24:37The lesson is don't make the a nudi angry
0:24:37 > 0:24:40- or face a poisonous snot attack. - Absolutely.
0:24:40 > 0:24:44The crown-of-thorns use deadly slime to digest prey,
0:24:44 > 0:24:48and the nudibranch creates its own poisonous slime jacket.
0:24:48 > 0:24:50Clever stuff. OK. Who's next?
0:24:52 > 0:24:56We all know the reef has to have coral, and the Barrier Reef
0:24:56 > 0:24:59here has the most beautiful coral in the world.
0:24:59 > 0:25:03But without the help of mucus, it wouldn't look so lovely.
0:25:03 > 0:25:05Corals are great big slime fans.
0:25:05 > 0:25:09Ever wondered why they don't dry out in the scorching sun?
0:25:09 > 0:25:13- Occasionally. - They produce their own sunblock.
0:25:13 > 0:25:18- Cool! So they have any spare? I could do with some.- Don't go there.
0:25:18 > 0:25:22It comes in the form of sticky, smelly mucus.
0:25:22 > 0:25:24Snot sunblock. Of course.
0:25:25 > 0:25:27You can see it glistening.
0:25:27 > 0:25:32So, like the nudibranch, they rely on mucus to protect themselves.
0:25:32 > 0:25:34Snot, I mean spot on!
0:25:38 > 0:25:40I'll never blow my nose again
0:25:40 > 0:25:44without marvelling at the superpower of snot.
0:25:44 > 0:25:45- It's just a bogey.- I know.
0:25:45 > 0:25:50But this is the ocean world, we both know it's a bit more than bonkers.
0:25:50 > 0:25:52Well, let's SNOT argue!
0:25:52 > 0:25:57Sorry, I couldn't resist it. Seriously, it's time for a Reef-Cap.
0:26:06 > 0:26:09He looks like a rhino, but feels like a blancmange.
0:26:09 > 0:26:12The slimy rocking rhinopias fish.
0:26:12 > 0:26:17Linked to baby chromis whose first meal is their parents' snot. Gross!
0:26:17 > 0:26:22Not as gross as the cleaner wrasse who cleans it off anyone who asks.
0:26:22 > 0:26:23Not my idea of a good job.
0:26:23 > 0:26:28Clownfishes know that by wrapping themselves in anemone mucus,
0:26:28 > 0:26:30they can live there sting free.
0:26:30 > 0:26:34The parrotfish has to spend 30 minutes making a snot cocoon
0:26:34 > 0:26:37to make sure he's safe from predators.
0:26:37 > 0:26:41I'd do that if it meant I was safe from the blue ringed octopus,
0:26:41 > 0:26:44whose deadly spit can kill 26 humans.
0:26:44 > 0:26:48Thank goodness for the porcelain crab and his silly dance.
0:26:48 > 0:26:53His mucus hands mean he only has to wave in the air to grab some grub.
0:26:53 > 0:26:57The funny feather duster worm, the cutest worm I've ever seen,
0:26:57 > 0:27:01has a fan of the slime to eat, but also keeps the water clean.
0:27:01 > 0:27:04The sea cucumbers are just one big slimy lump.
0:27:04 > 0:27:07So snotty, the food just sticks to them.
0:27:07 > 0:27:10But, sorry, nothing beats a poo cannon.
0:27:10 > 0:27:13Not forgetting the crown-of-thorns,
0:27:13 > 0:27:16who push their stomachs out of their mouths and feed.
0:27:16 > 0:27:19- That surely is as gross as it gets. - Almost!
0:27:19 > 0:27:22Deadly poisonous slime comes close,
0:27:22 > 0:27:25no wonder the nudibranch looks so happy.
0:27:25 > 0:27:30No-one loves mucus as much as coral. They make their own snot sun lotion.
0:27:30 > 0:27:34- That was slime, snot and guts. Good fun, wasn't it?!- Yeah.- Cool.
0:27:34 > 0:27:39- I'm going to go now. Me too. See you later.- OK.- All right. Bye.- Bye.
0:27:42 > 0:27:45I new you were going to do that!
0:27:45 > 0:27:49See, great minds think alike! So, that's the slime and the snot.
0:27:49 > 0:27:51Where's the guts?
0:27:57 > 0:28:00Subtitles by Red Bee Media Ltd
0:28:00 > 0:28:03Email subtitling@bbc.co.uk