- 3 years ago
Category
🐳
AnimalsTranscript
00:00 Australia, a tropical paradise.
00:07 But these pristine waters conceal sinister undercurrents.
00:17 The oceans surrounding this island continent are home to some of the deadliest creatures
00:23 known to man.
00:31 Marine assassins that strike from the shadows.
00:36 Or wield biological weapons that kill with terrifying efficiency.
00:45 Curiously intriguing.
00:52 Exquisitely beautiful.
00:57 And exceptionally lethal.
01:11 These are the case files of Australia's notorious ocean killers.
01:19 From otherworldly predators with a knockout punch, to flamboyant femme fatales, to the
01:29 monsters of our deepest nightmares.
01:34 In these waters, there is little more fearsome than the jaws of the great white shark.
01:51 Perfectly adapted marine predators, sharks have prowled the oceans for more than 400
01:57 million years.
02:03 Worldwide there are around 400 species of shark.
02:08 Almost half of which can be found in the waters surrounding Australia.
02:14 Monsters of the deep.
02:16 The stuff of myth and legend.
02:23 They are supreme killers.
02:30 Over the last 50 years, there have been 53 fatal shark attacks in Australian waters.
02:40 But usually these so-called man-eaters prefer prey of a different flavour.
02:49 Hammerhead sharks hunt stingrays.
02:55 Tiger sharks attack and kill turtles and even other sharks.
03:01 But there is a giant amongst their number with a taste for warm-blooded victims.
03:07 It's the largest of all flesh-eating sharks.
03:12 The great white.
03:15 One of the most feared predators on earth.
03:19 But it is not human flesh that whets this monster's appetite.
03:24 Inhabiting the colder coastline of southern Australia, fur seals make for tempting appetisers.
03:33 While sea lions are the main course, the colonies here make up a significant part of the great
03:38 white's diet.
03:41 This alpha male sea lion watches over a group of females and their pups.
03:50 On land they appear cumbersome and clumsy.
03:59 But once they enter the water, it quickly becomes apparent that they are in their element.
04:09 Sea lions are fast, agile and elegant swimmers.
04:14 Their streamlined bodies enable them to efficiently chase down prey species like crustaceans and
04:21 cuttlefish.
04:22 But the sea lions aren't the only marine predators to prowl the chilly waters of the
04:30 great southern ocean.
04:34 And all this activity does not go unnoticed.
04:40 A nightmare of the deep approaches.
04:47 Great white sharks can detect the scent of prey species from great distances.
04:55 For this 15-foot long monster, the sea lion hunting ground is a smorgasbord.
05:03 Busy with their own hunt, the adult sea lions are oblivious to the approaching threat.
05:09 And the great white seizes the opportunity to target one of the pups.
05:19 Weighing around one ton, it breaches the water's surface at over 30 miles an hour.
05:30 Returning to the beach, the adult sea lions have one less mouth to feed.
05:38 Even the most attentive of parents have little hope of defending against such an overwhelming
05:43 force of nature.
05:48 A veritable powerhouse, the great white shark terrorizes the Australian coastline with brutish
05:59 strength and fierce jaws.
06:03 But Aussie killers come in all shapes and sizes.
06:08 And to survive in this bloodbath, even the most delicate of Mother Nature's creatures
06:14 have come to rely on lethal biological weapons.
06:22 Far from the frigid waters of the great southern ocean, the warm seas of Australia's tropical
06:29 north appear to be a swimmer's paradise.
06:35 But looks can be deceiving.
06:40 Every year from November to April, blooms of jellyfish lay siege to Australia's northern
06:46 coastline.
06:51 While some are harmless, others are amongst the deadliest creatures known to man.
07:00 The venom of the tiny Irukandji jellyfish is a hundred times more potent than a cobra's
07:08 and a thousand times deadlier than that of a tarantula.
07:18 But Irukandji aren't considered to be the most dangerous marine stingers in these waters.
07:26 That title belongs to the box jellyfish, one of Australia's most notorious killers.
07:34 Over the last 130 years, these aquatic assassins have claimed the lives of more than 70 people.
07:44 The rapid onset of box jellyfish envenomation can lead to cardiovascular collapse and death
07:52 in a matter of minutes.
07:56 It's a terrifyingly efficient way to subdue prey, which is typically small fish.
08:04 Stinging cells contained within the 10-foot-long tentacles inject venom upon contact, bringing
08:11 about a quick death.
08:15 The extreme nature of the jellyfish's chemical weapon helps to protect its delicate tentacles
08:21 from being damaged by a struggling victim.
08:25 Although not as ferocious as the great white shark, these toxic terrors have few natural
08:32 predators.
08:36 Present in vast numbers, jellyfish blooms can stretch as far as the eye can see.
08:43 But sometimes it's the things that we can't see that pose the greatest threat.
08:49 Hiding on the sea floor is a clandestine predator with a deadly reputation.
08:56 The reef stonefish.
09:10 Spanning over 1,250 square miles, Australia's Great Barrier Reef is the largest living structure
09:19 on the planet.
09:21 But amongst this beauty, unseen terrors lie in wait.
09:34 Shunning the limelight, a reef stonefish conceals itself on the sea floor.
09:41 A master of disguise, it's easy to see how this predator got its name.
09:51 Its mottled colours blend in with the reef setting.
09:56 It will even tolerate algae growing on its skin to further aid concealment.
10:05 The stonefish is an awkward swimmer.
10:12 But it's patient, a required trait for an ambush predator.
10:22 By burying itself in the sandy seabed, it becomes almost invisible.
10:34 Even its large bulbous eyes are indistinguishable from its surroundings.
10:41 This nocturnal predator preys on crustaceans, small fish and cephalopods that stray too
10:49 close.
10:57 The slightest movement would betray its presence.
11:02 Surprise is everything.
11:08 The stonefish's strike is explosive.
11:20 Its wide gape rapidly envelops unwary prey, which is swallowed whole.
11:31 Its use of surprise attack makes it a formidable predator.
11:38 But the stonefish is most renowned for its deadly defence.
11:44 It's the most venomous fish in the world.
11:52 Concealed within its dorsal fin are 13 needle-like spines.
11:57 Fed by venom glands, these spines form a lethal defensive array.
12:04 A toxin unique to stonefish, known as varruca toxin, attacks the nervous and circulatory
12:10 systems, and can prove fatal to would-be predators.
12:17 In humans, stonefish envenomation can result in severe pain and life-threatening restrictions
12:24 to blood flow and breathing.
12:28 Hunters beware.
12:30 More often than not, these silent assassins will have the last laugh.
12:43 The reef stonefish has made an art form of concealment.
12:48 Lurking within the shallows is another marine assailant, one that employs a more proactive
12:54 strategy.
12:56 It advertises its message in neon blue, "Touch me and you die."
13:14 Roughly the size of a baseball, the soft-bodied blue-lined octopus looks deceptively vulnerable.
13:24 And with a relatively short lifespan of just seven months, the species depends upon some
13:30 rather extreme survival strategies.
13:38 This sea snake is prowling for food.
13:43 The octopus has a choice to make.
13:46 Hide or stand and fight.
13:50 It opts to hide.
13:54 Like most cephalopods, the blue-lined octopus is a master of disguise.
14:01 Sophisticated skin tissues allow it to rapidly change not only its colours, but also the
14:07 texture of its skin to better blend in with its surroundings.
14:16 The sea snake continues its search for a meal.
14:25 But some predators are armed with more refined senses.
14:38 The hammerhead shark possesses an array of electro-receptors that can detect even the
14:44 best hidden of prey on the seafloor.
14:49 Confronted with the threat, the blue-lined octopus decides to change tactics.
14:56 It sends a vivid message.
14:59 Iridescent blue markings pulsate across its body, warning the predator that it's armed
15:07 and dangerous.
15:15 Its deadly bite is 10,000 times more toxic than cyanide.
15:22 In humans, envenomation can cause respiratory failure, leading to cardiac arrest and eventually
15:29 death, in as little as a few minutes.
15:34 In nature, such threat displays are generally heeded, and the hammerhead continues on its
15:41 way.
15:46 On a smaller scale, the blue-lined octopus is also a predator.
15:52 It scours the ocean floor, searching for small fish and crustaceans.
15:58 As a soft-bodied cephalopod, it's vulnerable to counterattack, and this crab's pincers
16:04 could inflict grievous bodily harm, albeit in self-defense.
16:15 A surprise attack presents the best chance of success.
16:33 The octopus's dexterous tentacles restrain the crab's menacing claws, while its sharp
16:40 beak easily penetrates the crab's exoskeleton, delivering its toxic bite.
16:49 The crab quickly succumbs to a lethal combination of toxins contained within the octopus's venom.
16:58 There's no doubt with this pint-sized perpetrator, blue means back off.
17:12 Flashing its blues works well for the octopus, a vivid warning signal.
17:20 But when danger comes close, it helps to pack a powerful punch.
17:36 Amidst the strange and often brutal underworld of this subaquatic realm, one puny pugilist
17:48 stands out from the crowd.
17:51 The peacock mantis shrimp.
17:56 Otherworldly in appearance, there's more to this odd creature than meets the eye.
18:04 It's a formidable predator.
18:10 Its bizarre appearance is the result of 80 million years of evolution.
18:17 With an appendage for every occasion, the peacock mantis shrimp is the Swiss Army knife
18:24 of the marine world.
18:32 Five pairs of legs for feeding.
18:35 Three pairs of legs for walking.
18:38 Two pairs of antennae for reception.
18:43 Ten gills for breathing.
18:47 Two eye stalks bearing an extraordinary pair of compound eyes.
18:54 And even a set of windscreen wipers.
18:59 But of its 34 appendages, it's those club-shaped limbs at the fore that make it a true killer.
19:12 At just six inches, he punches well above his weight.
19:20 His hunting strategy is one of brute force.
19:26 Understandable when prey species include the well-armed and well-armored.
19:33 Not to mention well-camouflaged.
19:39 But camouflage is of little use when hunted by a peacock mantis shrimp.
19:47 His eyes are amongst the most complex in the animal kingdom.
19:54 While human eyes have just three color photoreceptors, he has 12.
20:00 With the capacity to see far beyond the human visible spectrum, very little escapes his
20:06 attention.
20:12 While the crab's defenses are formidable, this seasoned brawler treats them with contempt.
20:20 He's more than a little territorial and knows exactly who's moving through his patch.
20:27 Especially those of the tasty variety.
20:33 Unaware of the mantis shrimp's presence, the crab strays close.
20:40 Too close.
20:46 With the velocity of a .22 caliber bullet, the mantis shrimp's strike is the fastest
20:54 in the animal kingdom.
21:00 The assault is so fast that friction makes the surrounding water boil.
21:15 The devastating punch knocks limbs off the victim and delivers a quick death.
21:22 With built-in cutlery at his disposal, his home-delivered crab meat meal is ready to
21:29 eat.
21:34 The peacock mantis shrimp punches well above its weight.
21:40 But there are far larger brawlers lurking in these waters.
21:45 Prowling the coastline, one heavyweight killer devours just about anything that crosses its
21:52 path.
21:53 The tiger shark.
22:05 The complex structures of Australia's Great Barrier Reef form the foundations of a bright
22:11 and bustling metropolis.
22:18 Almost every neighborhood has its bully.
22:27 Growing to more than five meters long, tiger sharks are aggressive predators.
22:36 In these waters, few are safe from their insatiable appetite.
22:42 Tiger sharks are responsible for a large percentage of fatal attacks upon humans.
22:50 But these monsters will more often prey on marine mammals, stingrays, even other sharks.
23:03 In Australia's far north, tigers have developed more refined tastes.
23:11 They've become specialized hunters.
23:15 Between November and April, tiger sharks gather here in large numbers, travelling from as
23:21 far afield as Papua New Guinea.
23:25 They're attracted by a natural phenomenon.
23:31 Rain Island is the world's largest green sea turtle nesting site.
23:37 But to lay their eggs, the sea turtles must make it to shore.
23:42 And that's no easy feat.
23:45 As they approach the beach, the sea turtles must run the shark gauntlet.
23:51 Tigers prefer to launch their deadly assault from below.
23:56 So the sea floor offers some protection against surprise attack.
24:01 But the turtles must occasionally surface to breathe.
24:13 And that puts them in mortal danger.
24:18 For the sea turtles, timing is everything.
24:22 This one has spotted the lurking predators and bides her time.
24:29 However, chances are breath.
24:37 And pays the ultimate price.
24:41 Once dispatched, the tiger shark uses powerful jaws and serrated teeth to dismember its victim,
24:48 shell and all.
24:52 Amidst the feeding frenzy, the onlooker breaks from cover.
24:57 And makes a final dash for the beach.
25:00 She's one of the lucky ones.
25:03 Many turtles will not make landfall.
25:07 Instead, falling victim to the murderous appetites of the tigers that ruthlessly prowl the neighborhood.
25:27 With such menacing monsters in the water, it helps to be able to avoid detection.
25:34 Or have the capacity to defend oneself.
25:38 One fierce fish can do both.
25:43 The lionfish.
25:51 The cold-blooded killers in Australia's coastal waters are armed with jaws, harpoons and gruesome
26:02 spikes.
26:05 But few are as flamboyant as the lionfish.
26:12 It's named for its long flowing fins that resemble a lion's mane.
26:19 Beautiful, but deadly.
26:26 A femme fatale.
26:34 The lionfish's irregular outline helps to conceal its presence when viewed from a distance.
26:40 Another piece of seaweed wafting in the current.
26:44 But up close, its bright colors and bold markings serve as a vivid warning to would-be predators.
26:54 Look but don't touch.
27:01 Also known as devil firefish, lionfish are armed with potent venom.
27:12 Each long flowing dorsal spine is tipped with an extremely sharp point.
27:22 Glands within these spines produce powerful neurotoxins.
27:30 In humans, lionfish envenomation can cause extreme pain, respiratory paralysis and occasionally
27:38 death.
27:44 Their formidable toxins and vivid threat display have earned these fish a healthy respect amongst
27:51 the reef community.
27:54 They have few natural predators.
27:59 Although armed and fabulous, lionfish don't use their venomous spines to hunt.
28:06 They're strictly for defense.
28:09 They're ambush predators, relying on camouflage to sneak up on a victim.
28:21 Unaware of its presence, small reef fish make for easy targets.
28:39 By rapidly sucking water through its wide gape and pumping it out the gills, the lionfish
28:45 creates a vortex.
28:49 Dragging this hapless fish to its doom.
28:55 This femme fatale literally eats its victims alive.
29:02 Though only the size of a football, the lionfish sits comfortably near the top of its food
29:08 chain, a marine assassin with flair.
29:19 While the stealthy lionfish terrorizes inhabitants of the reef, there is another killer here
29:26 that attacks the reef itself.
29:29 A notorious predator that leaves death and destruction in its wake.
29:37 But it too has its nemesis.
29:46 Australia's Great Barrier Reef is a wonder of the natural world.
29:53 Yet it's under threat.
29:58 Rising sea temperatures, attributed to global warming, are killing off the corals that give
30:04 the reef its structure.
30:10 Adding to the peril is a natural-born coral killer.
30:23 At around 30 inches in diameter, an individual crown-of-thorns starfish can devour up to
30:30 30 square feet of coral in a single year.
30:35 Which might not sound like much, but when present in vast numbers, the results are catastrophic.
30:45 And these sea creatures produce more offspring than any other marine organism on earth.
30:55 Each female develops over 50 million eggs in a breeding season.
31:05 From the age of six months, the diet of juvenile starfish is comprised almost entirely of coral.
31:21 Its characteristic venomous spines protect it from most predators.
31:28 En masse, they are a force to be reckoned with.
31:33 Yet for the reef, there is hope on the horizon.
31:51 An unlikely predator.
31:54 The giant triton.
31:58 One of the ocean's largest sea snails.
32:02 Tritons can measure over a foot and a half from tip to tail.
32:12 This giant gastropod feeds upon sea cucumbers and sea stars.
32:23 The crown-of-thorns starfish seems to be one of its favorite foods.
32:34 When hunting, the triton uses scent trails to track its prey.
32:40 But it's not the only one with an acute sense of smell.
32:45 The starfish senses the approaching threat and attempts to flee.
33:00 The triton gives chase.
33:05 It may appear that these creatures are going nowhere fast.
33:11 But make no mistake, this is an active pursuit.
33:16 A race to the death.
33:25 With nowhere to hide, the starfish relies on its venomous spines as a last line of defense.
33:38 But the starfish's defenses offer little deterrent to the persistent predator.
33:47 Giant tritons have developed a tolerance to the starfish's toxins.
33:54 And their saliva contains a paralyzing agent which brings the pursuit to an abrupt halt.
34:02 This hard-fought meal is now ready for consumption.
34:09 It uses a serrated organ known as a radula to lacerate the soft tissue between the starfish's
34:16 spines.
34:18 Then sucks the life from its paralyzed victim, leaving little behind but an empty husk.
34:28 But as is the nature of a sea snail, it's in no hurry.
34:43 While giant tritons patiently stalk their prey across the sea floor, other marine predators
34:51 move with speed and precision.
34:55 The streamlined bodies of sea snakes have evolved to be fast, agile and deadly.
35:09 A toxic serpent stalks Australia's reefs.
35:19 A six-foot-long predator with a lethal bite.
35:26 The olive sea snake.
35:32 Unable to move on land, the olive sea snake is extensively adapted to an aquatic lifestyle.
35:43 But like all snakes, it's an air-breathing reptile.
35:52 It has a giant lung that runs nearly the length of its body, allowing it to stay submerged
35:59 for hours at a time.
36:04 As it tracks small fish and invertebrates amongst the nooks and crannies of the reef.
36:19 Specialized valves in the sea snake's nostrils prevent water from entering its lungs when
36:24 diving.
36:27 And while its vertically flattened tail provides propulsion when on the hunt, it also serves
36:34 to protect the snake from becoming the hunted.
36:40 Like eyes in the back of its head, photoreceptors on top of its tail act as an early warning
36:46 system to detect passing predators, giving the serpent a head start on hiding from hungry
36:54 eyes.
37:00 But for the prey species of this stealthy assassin, there are few places to hide.
37:15 Offering a false sense of security, the confined space of this fish's refuge is easily infiltrated.
37:26 The serpent strikes with the longest fangs of all sea snakes, injecting neurotoxic venom
37:33 and fast-acting peptides that lead to almost instantaneous paralysis.
37:40 Potentially lethal to humans, this highly toxic venom claims the fish's life within
37:47 moments.
38:04 While sea snakes actively hunt down their prey, there are other nefarious characters
38:12 amongst Australia's marine assassins that prefer to lure unsuspecting victims to their
38:19 death.
38:29 In these sinister waters, deceit and deception are commonly employed as survival strategies.
38:38 The dark art of camouflage, a prime example.
38:45 It's frequently used to set up a kill or avoid being killed.
39:00 This is one of the craftier perpetrators, the anglerfish, capable of adapting their
39:07 appearance to suit their environment.
39:10 These colourful conmen are masters of disguise.
39:15 Instead of swimming, they use their fins to slowly prowl the sea floor in search of prey,
39:22 like small fish and squid.
39:28 In its bag of tricks, this anglerfish possesses a rather unusual tool.
39:38 A biological lure, known as an esker, protrudes from its forehead.
39:45 Resembling a wriggling worm, it tempts prey from the safety of cover.
39:54 A cuttlefish emerges to investigate.
40:00 Amongst the most intelligent of marine invertebrates, it doesn't buy into the scam.
40:11 Nearby a painted anglerfish casts its line, but just in case the lure isn't tempting
40:18 enough, it also secretes a chemical attractant into the surrounding water.
40:31 Its strike is faster than the blink of a human eye.
40:35 A bite-sized snack.
40:44 These remarkable predators are capable of taking much larger prey.
40:50 Anglerfish can expand their mouth cavities to 12 times the original size, a trait that
40:57 allows them to punch well above their weight.
41:04 Also reliant on camouflage, a flounder conceals itself within the sandy seabed.
41:12 Unaware that a hairy anglerfish is posing as a sea anemone nearby.
41:27 Attracted by the disturbance in the sand, the anglerfish moves in to investigate.
41:37 This big-mouthed predator is quite capable of devouring the flounder whole.
41:47 Putting faith in its camouflage, the flounder holds its nerve.
41:56 Fooled by the flounder's disguise, the anglerfish moves off in search of its next victim.
42:08 Anglerfish are amongst the craftiest killers on Australia's reefs.
42:13 Another predator here uses more insidious drugs to subdue a victim before moving in
42:22 for the kill.
42:32 Activity on the reef ebbs and flows with the sunlight filtering to the seabed.
42:42 As the moon rises above the black waters, one of the planet's deadliest creatures
42:49 embarks on its hunt.
42:53 It's not as imposing as a killer shark, nor does it instill primal fear as a snake might,
43:04 but it wields one of the animal kingdom's most potent chemical weapons.
43:11 Its sting is a death sentence.
43:18 Having kept a low profile throughout the day, this predator emerges from its sandy hiding
43:24 spot.
43:30 A carnivorous cone snail.
43:38 Its movements are deceptively slow, but it conceals a lightning-fast pneumatic weapon,
43:47 one that delivers a fatal dose of venom.
43:52 Conus geographus is the most deadly of all the cone snails.
43:59 Its venom is more complex than the deadliest of snake venom, and has claimed the lives
44:05 of more than 30 people.
44:10 There is no anti-venom to treat its fatal sting.
44:21 The cone snail prowls the ocean floor, creeping forward with its muscular foot.
44:31 Its siphon, packed with chemo sensors, probes the water.
44:38 With this appendage, it can sense the chemical trails of prey from considerable distances.
44:45 It's picked up a scent.
44:56 A venomous weaverfish.
45:01 The dorsal spines of this fish are delivery mechanisms for its own mix of defensive toxins.
45:11 But the cone snail is undeterred.
45:16 As the sinister assassin creeps towards its mark, the faster-moving weaverfish makes no
45:23 attempt to flee.
45:25 It's paralyzed, not by fear, but by a mixture of chemicals that the cone snail has released
45:33 into the surrounding water.
45:36 Fast-acting sedatives that immobilize prey.
45:41 The cone snail now casts its net.
45:46 Its extendable mouth begins to engulf the weaverfish.
45:51 Its elastic appendage doubles the snail's length and appears impervious to the weaverfish's
45:57 toxic defenses.
46:00 With the fish trapped, the cone snail extends its proboscis and readies a kill shot.
46:10 It fires a hollow tooth filled with toxins.
46:17 The harpoon floods the fish with venom, instantly attacking the nervous system and shutting
46:24 down nerve impulses, quickly leading to the prey's demise.
46:35 The cone snail begins its slow escape from the scene of the crime.
46:44 Returning to its darkened lair to ingest its meal in solitude and safety.
46:55 When next holidaying on an Australian beach, you should remember one thing.
47:01 The crystal clear waters of this island paradise are both beautiful and deadly.
47:09 Weaverfish plague the shallows.
47:14 Lethal octopi haunt the rock pools.
47:19 And great white sharks will see you before you see them.
47:25 Applying the tools of their trade, these deadly Australians are closer than you think.
47:42 [Music]
48:02 [BLANK_AUDIO]
Comments