Exploring The Underwater World | 4K UHD | Blue Planet II | BBC Earth

more than half of all animals in the open sea float on currents, jellyfish cross entire oceans feeding on anything that gets tangled in their tentacles, some can grow up to a meter or even 2 m wide and, when luckily, They find a piece of sea rich in plankton, their numbers explode, it is such a successful strategy, jellyfish are one of the most common forms of life on the

planet

, but among jellyfish, and which looks a bit like them, there are a much more complex and sinister creature, the Portuguese warship, which floats with the help of a gas.

Full bladder topped by a vertical membrane that serves as a sail. Maintains a constant course through the waves. Behind it trail long threads up to 30 m long, each armed with thousands of stinging cells. A single tentacle could kill a fish or in rare cases, a human, but among its deadly tentacles, you find a Mana War fish that feeds by nibbling on them, once this fish has some resistance to bites, you still need to be very careful. , most other fish aren't so lucky if a tentacle catches it and coils up. In their already paralyzed specialized muscular tentacles they transfer the victim to others that digest the catch and liquefy it with powerful chemicals.

Eventually all that is left is a scaly shell. This voracious man of war can collect more than a hundred small fish in a day in the fight to survive. in our green seas it can have far-reaching consequences once a year a particular grassland in Australia transforms around the first full moon of winter an army materializes spider crabs for the past year that have been feeding in deeper waters and now They march across the seagrass plains hundreds of thousands of them climb over each other creating large mounds almost 100 m long they do not look for a mate or lay eggs they have come here to grow like all crabs their bodies are enclosed in a hard shell and inexpandable to To grow, they have to come out of it and that allows the soft that has developed underneath to expand.

The new shell will take days to form. His legs are so limp that they do not function properly. The crab is unprotected and in great danger. A smooth stingray is huge, about 4m long, you want a soft, newly formed crab that is easier to eat. The crabs try to stay together, but now, disturbed by the lightning, they are scattering. A newly formed crab is too weak to keep up. crowd the safest place is right in the middle of the pile that is why everyone has gathered here there is safety in numbers but the vast majority of the crabs escape and within the next few days they will be ready to return to the depths and continue their solitary wanderings in search of food this is not a cemetery, but the Triumph of 100,000 crabs successfully molted a crab Sally Lightfoot one of the thousands of coastal crabs that bide their time every day they gather on the tropical shores of Brazil waiting for the tide goes out which exposes their feeding areas rocks covered in algae 100 m from the shore to get there there is a race against the tide they jump from rock to rock these crabs seem to be afraid of the water and for good reason the moray eel Moray chain is a specialist crab hunter, his blunt teeth can easily grab and crush the shell of a crab.

She is the deadliest enemy of the crab, but the feeding areas of the crabs are still far away. They must press halfway, but the enemy has other ideas for crossing the land and reestablishing the ambush to feed. The crabs must move on, but nowhere is safe. An octopus is also a crab killer. The crabs rush towards him. They risked life and limb to graze on these algae pastures, but in 2 hours, when the tide starts to turn, they will have to. Run the challenge again In a far corner of Southeast Asia lies the Custer Coral Triangle, one of the richest coral reefs in the

world

,

underwater

cities teeming with life, as in any crowded metropolis, there is a fierce rivalry for the space for food and for a companion but the reef is also a place full of opportunities a cuttlefish specializes in hunting crabs but a large crab is a dangerous quarry it has powerful claws the cuttlefish however has a remarkable talent its skin contains millions of cells pigments with which you can create constant changes colors and patterns and that apparently hypnotizes the crab a cuttlefish may be intelligent but a shark is bigger and eats cuttlefish it is time to disappear again to hunt a new target but the same fascinating technique for those Those who manage to establish themselves in these bustling

underwater

cities can have great rewards during the dry season.

Over half a million Raven laps in this remote ATL in the Indian Ocean. Their chicks still have their dark juvenile plumage. They vary in age, while more advanced chicks fly. Others are not yet. Still ready, those just beginning to learn to fly use the shallow lagoon in the center of the atole as a training ground. It is difficult for some of them to stay afloat during long giant voyages. They are generally solitary hunters, but about 50 of them have come here. from neighboring reefs attracted by this abundance of potential prey, the newbies stay out of the water if they can, even drinking while flying if the chalia wants to catch one, now they have to up their game, so here's a fish that surprisingly has a brain. able to calculate the air speed, altitude and trajectory of a bird, the time comes when each fledgling has to fly and collect food for himself, his parents go to the training grounds and if they want to survive, they must learn quickly after a month. from practicing on the lagoon the young people begin to leave and take risks in the open sea here in the sand Apartments there is safe accommodation for some a family of black clownfish Chair has found an excellent home the tentacles of this carpet are enony can kill, but the Clownfish are immune to poison, so they can protect themselves from danger.

In exchange, the fish keeps the anemone clean of debris, as with all clownfish, the family is ruled by a large female, her white face marks her as the boss, the dominator. The male has to prove his worth so he works tirelessly removing debris and generally keeping on top of household chores. His biggest challenge is finding a safe place where the boss can lay her eggs, but there is nothing solid here for the female to lay them. The nearby shell might be the solution if you could move it to the protection of the anemone, which is too heavy, plus it has the mind of your own hermit crab.

Here twice a day, the anemone is carried away by tital currents and brings new opportunities. an old plastic bottle maybe this isn't heavy enough a coconut shell looks good but it's too far from home and he can't move it on his own so now the pair works together it's a small adjustment to the anemone tentacles in order to clear a space for it and the shell is tucked into the female he puts up a safe nursery he has finally proven himself worthy of fathering his young and fertilizes them now he will meticulously care for the eggs keeping them clean and healthy until they hatch in 10 days time The

blue

shark travels more than 8,000 kilometers a year riding currents supported by its wide, wing-like fins.

It may not have eaten for 2 months, but the current can carry promising traces of fatty oils from many kilometers away and will lead you to your next meal after days of travel the smell of the food becomes stronger a dead whale recently hit by a ship this could be a real party but the

blue

shark must be careful great white sharks 10 times heavier That a very possessive blue around a whale Dead white sharks are eager to feed on energy-rich whale blubber, which we now know forms an important part of their diet once the great white shark has had its fill.

Smaller sharks like the blue shark deal with the remains of a carcass as if they were oils from this dead whale. It spreads more and more and more blue sharks appear in a few days the carcass will be stripped of its fat and its oil will no longer keep it floating it will sink into the depths below the blue with its fat reserves replenished it can now survive another 2 months without eating , but most creatures come together for a very different reason to breed the giant cuttlefish, the largest of all cuttlefish, they live only one or two years.

Now that the Australian summer comes to an end, they have one last act to complete to find a mate, but there are more than 100,000 males competing for females arriving in this bay, among them a giant, a true Goliath, probably weighing about 10 kilos. Colored bands run through his skin, this is how the cuttlefish communicates. This smaller male couldn't take him on. At Goliath's side and under his protection, a female who has just mated with him but other rivals are still interested, it seems that a small male would have no chance, the female now shows a white stripe along her side closest to him.

Goliath, it is a clear sign that she no longer wants to mate with him. It is all the stimulation the little male needs. He will have to use a trick. He lowers the tone of his colors and gets into her arms. He is just the right size to imitate a female. Goliath is fooled the small male now displays a white stripe like the real female to deter her advances, slides to her side and they find themselves meeting multiple mates. The female ensures the greatest genetic diversity for her offspring. The cunning male leaves his final act complete, so even among the giant cuttlefish it looks like it's Not all about size in the underwater forests of northern Japan, residents of this sunken ship expect summer temperatures to reach 16°C , which for some is the time to mate, a species of giant Rass called cobod, this is a male and in female terms he is particularly handsome, he is one meter long and weighs 15 kilos, much more than the female dimin and he is ready to breed.

He tries to join her and any of the other dozen females that live in her territory whenever he arrives. the possibility, but females around 10 years old do not realize their advances, this is because when a large female reaches a critical body size, a dramatic transformation can begin in just a few months, certain enzymes within her body stop functioning and male hormones begin. to circulate as time passes, her head expands and her chin lengthens and she has transformed into a he and with this comes a change in temperament. The old male who ruled all the females here is challenged to confront the more bulbous the head, the more intimidating and opponent the territory has a new ruler.

Only the larger females are transformed in this way but the change allows them to have more mates per So they will have many more babies carrying their jeans but a new male cannot afford to be complacent inside the body of each female cobod. Hey there is a new mail waiting and the energy of the waves creates imposing fortresses like these cliffs in the Arctic , home to tens of thousands of breeding seabirds. The cliff faces are accessible only from the air and have many corners. and nooks and crannies for those who can get there, but to feed the seabirds they must still master the

world

of the ocean Beyond a puffin, he is a fisherman and a father, he has a mate for life, they both share the burden of raising their old man and weak chick, his puffin that needs five square meals. one day the parents alternate fishing trips, it is dad's turn when the fish populations are scarce the puffins must fly up to 50 km out to sea to reach the good fishing areas once there they dive into another world good places to fish They are hard to find and have Gilot for company like the puffin there, their wings are short and good for diving.

Puffins can hold their breath for more than a minute and dive to depths of up to 40m, but it's a long way home after a grueling 100km round trip they almost made it. But there are pirates on this coast. Arctic skewers everywhere. Returning parents are being robbed. The skewers have a long back. The wings make them faster and more maneuverable. Puffins must choose their moment wisely. They almost failed. The last desperate burst of speed has arrived safely home afterwards. a 3 hour round trip where your patient companion is waiting for your puffin to eat today, but where fish numbers are declining, many puffins are now finding it difficult to get enough food for their chicks in today's changing seas, you can It will be even more difficult to be a successful puffin father a kilometer from the surface beyond the reach of the sun a gigantic black void larger than all the other habitats in the world combined there is lifehere, but not as we know it Extraterrestrial creatures produce dazzling light displays Almost all animals need to attract mates and repel predators, this light language is so widespread here that these signals are probably the most common form of communication throughout the world.

planet

and yet we still know little about them.

Hunters light up and, in doing so, attract curious prey. Tooth has the largest teeth for its size of any fish. It has precious sensors all over its head and body that can detect any movement in the surrounding water. It is the fiercest fish in the Midnight Zone, but the prey used light as a distraction. luminous ink lure Down here in this Darkness, creatures live beyond the normal rules of time. Siphonophores are practically eternal. They clone themselves repeatedly. Some eventually grow larger than a blue whale. Down here it snows continuous clouds of organic debris that slowly descend from above.

This is food and a variety of it. Filter-feeding fish, jellyfish and delicate sea cucumbers depend on it. The 1% of marine snow that is lost is eventually deposited on the sea floor over millions of years, forming a layer of up to a kilometer thick is an empty plane that covers half of our planet's surface Planet The deep seafloor It may seem lifeless at first, but it is home to a unique group of mud dwellers. The sea toad is an ambush. Predator with a huge mouth and infinite patience. This fish has been living here for so long that its fins have morphed into something.

More useful feet help it crawl in the sea. Flower the flapjack octopus hovers just above the surface of the mud while delicately sifting through it for worms, but can move away at the first sign of danger in the Gulf of Mexico. These eruptions also release a super salty liquid Brian, it is heavier than seawater and accumulates in large puddles at the bottom of the sea, it is difficult to understand. The site is an area of ​​salt water concentrated 15 m deep on the sea floor, around its margin, perhaps even more strange, there is a profusion of life, giant muscles that can live to grow for a century or more, They huddle closely together, dwarfing the shrimp and crouching down. lobsters that feed around them Cutthroat eels scavengers come to the shores of Lake Brian in search of something edible some even venture into the brine spending too much time in it can cause toxic shock in a sick person their only hope is to get over it they manage For Others escape they are not so lucky, Brian embeds their bodies and the ACC's decades-long casualties accumulate at the margins.