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[Music]
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the global ocean covers 71% of the surface of our planet holding within a realm as boundless as it is mysterious here beneath the shimmery surface lies a bustling Oasis teeming with life where every creature plays a vital role in the intricate dance of
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[Music] survival but 90% of the ocean lies in a place that sits quietly out of sight [Music] in the depths below the ocean plays host to a far stranger realm the deep sea this place is a world within our world a place of Silence emptiness and darkness one where wonders are found drifting in a formless void
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at the Deep's upper limit lies The Twilight Zone where the diminished light of the sun still holds Mastery over its
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processes it stretches from 200 M to a kilometer down beneath the waves but with the average depth of the ocean being almost four times deeper and the deepest known Point found at a depth of 11,000 M The Twilight Zone is little more than a [Music] lier the ocean's subsequent zones each command a greater
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expanse the midnight zone or bathy pelagic stretches to 4 km down a place so deep that the direct influences of the Sun the waves and the tides are not felt creating a habitat that has barely changed at all in millions of years [Music] at its lower limits the abyssopelagic begins which hosts a great desert of silth on the deep ocean floor called the abyssal plain a realm of mud [Music]
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dwellers at just a few SES around the world the ocean's final underworld plummets deeper still through great Rifts etched by tectonic processes these are the trenches or the hadel pelagic when it comes to unlocking their secrets each of these zones poses a greater challenge than the last but that hasn't stopped us from trying with some success and much still unknown [Music]
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since the late 20th century manned and remotely operated vehicles have granted access to the deep ocean [Music] like this one ROV Sebastian a robot owned and operated by Schmid ocean Institute it is the size of a small
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car and depth rated to 4 and 1/2 km its range covers the entirety of the Twilight and midnight zones
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controlled from the surface vessel via tether Sebastian shines a light on the deep and reveals a glimpse at the veiled expanse beneath the ocean surface
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but before we reach such depths we must pass through the epipelagic or sunlight zone which spans the upper limit of the water column down to a depth of 200 M it's a vibrant World more than 90% of all marine life dwells here and much of that belongs to the bustling cities of coral in the tropics where food shelter and reproductive partners not in short supply even out in the high seas the sunlet waters host an astounding array of
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[Music]
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life living near the surface opens up a niche that is not available in deeper waters by developing a gas-filled float called a neum metaphor the Portuguese man of war drifts at the surface and uses wind to move while downward-facing tentacles are used to feed they are members of the newon a community of floating animals that reside at the interface of air and water primary production is made possible near the surface by the rays of sunlight that filter through the waves
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microscopic plant-like animals called phytoplankton take on the role of producers converting water and carbon dioxide into oxygen and glucose via photosynthesis the biomass produced by this process supports all non- chemosynthetic life in the oceans and without it the depths below would starve dip below the epipelagic and we enter a world of Gloom this is the Twilight Zone or the [Music] mesopelagic from now on we are in the deep sea already at just below 200 M survival
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is more of a challenge there is not enough light for photosynthesis to occur and the great blue rooms of phytoplankton are
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absent the only food source is a steady shower of fecal pellets and dead material organic particles called Marine snow gently sinking from the bustling world of sunlight up above the presence of this Marine snow gives rise to a unique Niche that animals can exploit and the great Gloom brings forth the weird and wonderful many of these Treasures are gelatinous zo Plankton moving at the whim of the ocean swept by deep currents and unable to move against them a host of delicate Nomads drifting
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through the expanse
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[Music]
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the Gosa worm or tomopteris is a segmented worm belonging to a group called polites meaning many bristles and unlike its cousin the earthworm it moves not through sediment but through the open ocean it undulates its bristles like the paddles of a canoe in order to swim and after it's fed the gut within its transparent body reveals the color of its last meal but this can blow their cover since many of the animals it eats are bioluminescent creating light through a series of chemical
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reactions there are others that have found creative ways to overcome this challeng
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the bloody belly cone jelly undulates its hair like cyia to attract prey reflecting light to cast a rainbow Shimmer it takes on a deep red color to blend in since the wavelengths of red light do not reach the deep [Music] sea astonishingly adopting a red coloration conceals the stomach and filters out any light being emitted by the prey within while they're [Music]
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[Music]
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digested there are relatives of snails here too like cardiopad placenta a rare pelagic gastropod [Music] and another species carinaria Japonica with its large swimming fin that swims upside down in search of [Music]
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prey siphonophores related to fish are not one organism but many they are drifting colonies of tiny animals called zoids that work together and partition biological functions between different structures nectop fores act as swimming Bells assisting in propulsion in much the same way as the umbrella of a jellyfish pneumatophores help with buoyancy and at the far end gastroids dangle tentacles lined with stinging cells into the water [Music] the colonial way of life mirrors that of
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multicellular organisms with the Zoid structures seeming homologous to organs but it gives the siphonophores a unique advantage in most animals damage to one organ or physical structure can be fatal but if individual zoids become damaged it's less likely to affect the entire Colony they repeatedly clone themselves and can become a effectively [Music]
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Immortal in fact this siphonophore belonging to the genus aalia is thought by scientists to be the longest animal that has ever been observed rough calculations based on the position of the ROV suggest it reached 150 m in length significantly longer than the blue
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whale many tunics are also Colonial like pyrosomes and floating necklace-like salps all these Zoo Plankton examples can be classified as Hollow Plankton moving largely at the whim of the currents for the entirety of their life cycles meop Plankton on the other hand are only planktonic temporarily and are typically the lavel stages of fish or species that spend the adult stages of their life cycles in the benthos Far Below like mollusks Crustaceans and echinoderms who will one day settle on
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the sea floor
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[Music] for some animals the reverse is true and the lavel stage is cile the life cycle of many jellyfish begins with a polyp stage on the seabed planul lar settle and develop into aista before a sexually reproducing to produce a stack of developing juvenile mausi called aoba [Music] these juveniles Bud off one by one and develop into pelagic adult forms of
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[Music]
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jellyfish and the midw are full of them but since the sea Flor is so far away many jellyfish here lack a poly stage Al together and complete their entire life cycles in the water
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column some host the young ly within their Bell as they develop [Music] the dinner plate jelly swims with its tentacles extended forward a technique that allows them to stealthily sneak up on larger prey without startling them with large water movements remember in all the footage we're seeing the lights of an ROV are Illuminating the animals and the surrounding Waters so it's hard to imagine just how difficult it would be for prey to avoid slow moving Predators like this one in the
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Gloom there are also active swimmers necton rather than Plankton and a great number of them are spilop pods the squid octopus and cuttlefish
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the largest and most intelligent of the ocean
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invertebrates they are mollusks related to snails and B valves but their basic body structures are modified and specialized to make the most of life in the open ocean the mantle has become streamlined and a modified foot serves as a set of eight or more arms
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and of the 700 spilop pod species known to science none are more peculiar than those that inhabit the deep sea at 650 M down we find an octopus that is almost entirely seethrough this is a glass octopus and it's around 40 cm long and possibly longer the ey are one of only a few structures visible within its glass-like [Music] mantle the glass squid with its bulging eyes has also developed a body that is transparent most of the time when it suits them they change the
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color of their skin and fill their mantle with ink to turn deep red this ink also contains ammonia which is lighter than seawater and allows the squid to remain buoyant seethrough animals are more abundant in the deep ocean than anywhere else in the depths there are no harmful UV rays to necessitate cell pigmentation as a way to protect them from solar [Music] radiation inking is also used used for defense when spooked squids flee quickly and leave behind a shroud of ink in the
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form of a cloud rope or other shape resembling ghostly apparitions in the
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Gloom the ink masses are thought to be animal lookalikes dubbed pseudomorphs and they serve as a decoy
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[Music] some look like comb jellies or jellyfish others resemble
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siphonophores in some cases it may be advantageous for the squid itself to look like another animal this species the sword tail squid was observed mimicking seonor of the genus nomia the possess ornate taals that double the length of their bodies and seem to copy the shape and colors of their gelatinous
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neighbors they even position their tentacles in such a way that makes the deception more
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convincing siphonophores are not a dense source of food they are mainly water and this coupled with the stinging cells that line their bodies means they are kept off the menu for many animals as a result the juvenile sword tail squid appears unpalatable to Predators who mistake them for the [Music] siphonophores in their adult form chiro toothed squids become impressive Hunters [Music]
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[Music]
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the two tentacles are expelled rapidly tipped with clubs at the end lined with suckers for grabbing [Music] prey for nearly all creatures of the Twilight Zone there is one thing that gives them away to Predators when seen from below their dark Silhouettes stand out against the low levels of downwelling light but this challenge has given rise to some rather crazy creative methods of camouflage some use countershading expressing darker pigments on their upper body and lighter colors below in
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order to blend in from all [Music] angles others achieve this effect to a greater degree by emitting their own light bioluminescence produced from glandular organs called photo fors that line their bodies with a pattern of glowing dots like those of the Firefly Squid as they ascend they increase the intensity of their lights to match the levels of sunlight radiating from [Music] Above This principle even gave rise to a naval tactic called diffused light camouflage where counterillumination was
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used to make ships blend in against the backdrop of the night
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sky count illumination is one of three dominant methods of camouflage that midwater species employ to resemble their environment the second is transparency like we saw in The planktonic Drifters and glass squid and the third is
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silvering lacking scales and instead covered with highly reflective skin consisting of microscopic guanine crystals the needle like cutless fish resembles polished steel this effectively imitates transparency since although it stands out in the lights of an ROV the vertically oriented mirror makes these fish invisible from the side in the Dusky water [Music]
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[Music] it's so effective that almost all upper ocean fish species including sardines and Herring use silvering to blend in
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[Music]
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[Music] the hatchet fish has a laterally flattened body just a few millim thick making it almost invisible from head on and below
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and on its skin the Guan crystals are perfectly spaced to scatter any
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light but they also manipulate this light and funnel it downwards towards a set of photo fors on its belly where it contributes to their counterillumination
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[Music] this serves a dual purpose for towards the deeper extent of their range the downward scattering of light via their photo Force May throw off the search lights of midnight [Music]
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Predators silvering is found in sephila pods too using not guanine but proteins called reflectins to create a mirrorlike effect [Music] just as these deep sea dwellers have become impressive problem solvers today's sponsor brilliant is where you learn by doing with thousands of interactive lessons in maths data analysis programming and AI each lesson lets you play with Concepts and helps build your critical thinking skills through Hands-On problem solving not
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writing complex programs to build game and apps to try everything brilliant has to offer for free for a full 30 days visit brilliant.org nural World facts or scan the QR code on screen or you can click the link in the description you'll also get 20% off an annual premium subscription now let's Journey Back Down Into the Depths [Music]
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by living at this intermediate depth creatures of the Twilight Zone have an advantage the light levels are low enough that the Gloom provides a level of protection but just enough light remains that animals can use their remarkable light sensitivity to identify the coming of the night a time when predators of the surface waters become less active and and in response every night the denisons of the deep pay a visit to the shallows to feed on the Abundant
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phytoplankton it's a phenomenon called the Diel vertical migration
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[Music]
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as night falls vast numbers of animals rise from the depths of the mopic under a blanket of Darkness deep sea jellyfish siphonophores squid and many others gather near the surface to [Music]
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feed in their wake the entire food web of the mesopelagic follows and up from the depths come the innumerable sharks fish squid and all manner of deep sea Predators these vertical migrations unite plantonic organisms and their predators in a constant cycle of movement together they form the largest synchronous migration on planet
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Earth it's been postulated that animals May migrate at night to remain in their preferred light climate or is alum using this ability an estimated 5 billion metric tons of organisms migrate up towards the surface every night and back down come the dawn a mass movement so dense that it was first discovered when Echo Sounders on board World War II US Navy vessels detected the Gathering of animals as a mysterious second flaw in the ocean far shallower than the ocean
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bottom was thought to be as a gathering of creatures from vastly different groups the migration is a vertical Feast that fuels the ocean's food web take the lon fish for example they are the most widely distributed and abundant vertebrates on the planet with an estimated Global biomass of up to 16 gatons and accounting for 65% of all all fish biomass in the deep sea because of this they are a crucial food supply for many animals and a fundamental Link in marine food [Music]
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webs their most notable predators are the Red Devil squid which Gather in shs of up to 1,200 individuals near the surface every night [Music] their entire bodies flash red and white to signal to other members of the sh the reason is unknown it may be an invitation to reproduce or perhaps it's to warn others not to get too close for when the supply of lantern fish runs out they turn on each other cannibalism is Rife among Red Devils as studies of their stomach
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contents revealed the remains of fellow squid in a quarter of specimens this could explain how they're able to grow so large so quickly reaching well over a meter long in less than a
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year the 24-hour cycle of the vertical migration is one of the great forces that shapes the diversity and productivity of entire oceans [Music]
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it demonstrates the ability of life to make use of cycles and cues that allow them to exploit resources in different
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habitats Life In The Deep Sea would be nowhere near as diverse without the migration for the phenomenon sees midwater organisms feeding at the surface and bringing the acquired biomass and thus an enormous amount of carbon back down to depth here a few different processes see the carbon make its way to the sea floor it enters deep food webs via predation and sinks through the water column in the form of marine snow and fecal pellets this provides not only a means
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of sequestering carbon away from the atmosphere but also a vital ecosystem surface to deeper in communities by providing a more direct pathway for food to reach the midnight zone below where the total absence of sunlight makes vertical migrations far more
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[Music]
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challenging as the the ROV descends into the midnight zone we begin to encounter obscurities unlike anything observed near the
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surface some are so small that they are barely visible to the naked eye and others are
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giants this is a place of pure Darkness too deep for any light at all to penetrate it's a harsh environment with a large physical distance from the Plankton that form the base of food webs limits the abundance of animals that the midnight zone can
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support life here must find a way to function in a cold dark abyss where temperatures do not exceed 4° C and withstand extreme hydrostatic pressure that ranges from 100 atmospheres at the top of the zone to 400 at the bottom in spite of these challenges animals must make compromises and push their morphology and physiologies to the extreme in order to avoid Predators find food and locate mates amidst a massive pitch black void
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and so a set of surreal adaptations are [Music] employed soft bodies like that of the cuscal can withstand the crushing pressures that would damage or kill most other
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[Music] creatures metabolisms are slowed [Music] dramatically time ticks to a slower tune here it's the patient and the slow that grow [Music] old Greenland sharks belonging to the sleeper shark family are known to live for centuries 2,200 M down in the cold depths of the Arctic Ocean and growing longer than great whites up to 7 [Music] m like many animals down here they exhibit a phenomenon called Deep Sea gigantism the tendency of deep sea creatures to grow to sizes far exceeding
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those of their shallow water
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counterparts Predators belong to a trophic Niche you'd expect to be unsustainable in a place like this where food is scarce enough already for the Detroit of Wars so to conserve energy predators adopt sit and wait tactics using the dark to their
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advantage a comb jelly casts a net of tentacles lined not with stinging cells but sticky collar blasts that capture prey like a spider web
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I
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[Music]
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strips of fine hairlike cyia run the length of the body and are beat synchronously allowing the jelly to swim and refracting light in shimmering waves they also produce light of their own from special cells called photosites bioluminescence perhaps as a means of luring prey
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a low bait comb jelly lacks sticky tentacles it uses its cyia to create a feeding current engulfing prey
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while in the Twilight Zone bioluminescence is used to hide here it instead gives a voice to the lonely wanders of this midnight [Music] World a female anglerfish wields a lure called anesca filled with bioluminescent bacteria and poised at the tip of a modified dorsal fin Ray called an alysium [Music] encounters between angler fishes happen so rarely that many have gone to extreme lengths to maximize their reproductive success they exhibit exceptional sexual
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dimorphism the males display no Esa and are dwarfed in size by the females yet possess large eyes and nostrils that allow them to detect the species specific pheromones of the female and once he finds her a male will develop a pincer-like pair of tentacles in his jaw and latch on permanently to the female's body their circulatory systems combine and the male reduces to nothing more than a shriveled sperm producing sack nourished and sustained by the female's [Music]
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blood efficiency is key in the ocean and every aspect of an organism's anatomy and behavior is optimized to solve the challenges they face body shapes make a world of difference depending on the environment they [Music]
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[Music] inhabit in the sunlet waters of the high seas predatory fish spend most of their lives on the hunt [Music] water is 800 times more dense and 50 times more viscous than air making it a challenge to move through for a predator it helps to be streamlined with a rigid forked tail like that of the tuna this is a fusiform body type it minimizes inertial drag and allows tuna to migrate more than 15,000 km in a year at times reaching 43 mph
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fishes of the reef are compressed they require agility not speed and so are flattened side to side for quick accurate turns and darting among coral and [Music]
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rock on the sandy sea floor fish are flattened with preform [Music]
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bodies but what about here in the ocean's midnight void food is too scarce to support streamlined Predators there is no Rock to Dart among for cover nor any floor for miles [Music] there are two body types that seem to dominate rounded globo form fish like Anglers are suited not for sustained swimming but floating in weight of prey to come within
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[Music] reach others like the Sawtooth eel are elongate and
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flexible anguila
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form this form not only allows it to conceal its silhouette by hanging vertically when it Ventures into Twilight Waters but enables it to move in a series of sinuous waves that pass along the body and produce propulsive thrust for efficient swimming [Music]
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the snipe eel moves in a similar way but is thinner and more thread shaped with a body type known as fofor the jaws of its bird-like beak curve away from each other at their tips covered with tiny hooked backward pointing teeth for trapping minute crustations like shrimp as it sweeps through the water permanently a
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gape the snipe eel also boasts the most vertebrae of any animal on Earth with more than 700 along its meter and a half long [Music] body as fishes like these move flexible throughout their entire length the angula wave passes backward with increasing amplitude and speed producing the highest propulsive thrust in the [Music]
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tail it offers the most efficient method of locomotion in a place so starved of energy without compromising on speed as the Anglers
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have not being restricted to sit and wait tactics unlocks an assortment of feeding behaviors for anguilliform fishes like the oversized mouth of the gulper it is larger than the rest of the body and can be opened wide enough to scoop up shs of shrimp or swallow animals much larger than itself a pouchlike lower jaw holds the prey while its stomach distends within to accommodate and digest the feast there is a clear Trend too in the color of fishes here compared to the
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Twilight Zone the shimmering silvery fishes are fewer and instead a host of dark brown or black fishes prevail many boast an adaptation called Ultra Blackness with a surface covered in melanosomes containing extraordinarily high concentrations of the pigment melanin that reflects in some instances less than half a percent of the light that falls upon them it's in stark contrast to the reflective guanine crystals that allow silvering in fishes of The Twilight Zone
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where being so dark would only make their Silhouettes stand out in the sun's residual glow
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down here it's a superpower light organs located beneath each eye of this shiny loose jaw Dragonfish produce red bioluminescence that serves as a search light pray that a bright red in color which typically appear black down here stick out like a sore thumb in the red glow
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the black belly Dragonfish foro Ultra blackness in favor of brassy bronze skin using a bioluminescent barbell on its chin that acts like an angles
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[Music]
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lure the large backward facing teeth of the toothy viper fish are too large to fit inside its mouth but they act like like a cage ensuring prey can't escape once [Music] captured its fangs are formed from Crystal Nano structures so small that wavelengths of light pass through instead of scattering rendering them invisible to prey [Music]
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adorning the undersides of Dragon Fishes are bioluminescent dots used for counterillumination matching any light above when seen from
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[Music] below the Pacific blackchin scopal langis tristis has only been filmed in its natural environment a small number of times in many of these encounters it remains motionless perhaps to avoid being seen like the bronze dragon fish its silvery scales only shine when illuminated by the lights of an underwater robot but in the dark May scatter light and obscure the shape of the body very little is known about their life history like many fishes that hail from such depths
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Chimera is one of the oldest fish in the ocean an ancient relative of sharks that diverged from a common ancestor 200 million years ago running along its entire length is a lateral line system resembling Patchwork for sensing movements in nearby water for every 10 m we descend pressure increases by one atmosphere to survive fish have evolved strengthened protein structures and more fluid cellular membranes that preserve their vital biological functions for others including many
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spilop pods a soft gelatinous body is all they need to overcome the pressure and maintain neutral [Music] buoyancy water cannot be compressed so being composed primarily of water helps out down here the Dumbo octopus flaps a pair of enlarged ear-like mantle fins to move gracefully steering with webt arms as it traverses the
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void reaching depths of 6,000 M it is the deepest living octopus of all pressure at the lower end of its range can be 600 times greater than at sea level equivalent to the weight of 50 jumbo Jets although to us the conditions of the deep appear extreme the features that Define a challenging environment are always relative for many of the residents down here the ocean's surface is an extreme environment and the low pressure conditions of the shallows would prove lethal [Music]
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of The deeps Eclectic tapestry of animals the seapods are perhaps the most enigmatic displaying physiological morphological and behavioral modifications to become masters of this world each of them ethereal dancers pushing the boundaries of adaptation to sculpt an existence uniquely their
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[Music]
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own they dominate in a range of forms displaying unusual appendages for
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[Music] feeding the long sticky feeding tenacles of the Whiplash squid mtig opsis are draped like fly paper into the water below termed The Tuning Fork position as it basks in a cloud of its own ink [Music]
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[Music] [Laughter] [Music]
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[Music] when it's time to move on the tentacles are retracted into membranous sheaths within the Squid's arms
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[Music]
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the large eye of the strawberry squid allows it to spy the Silhouettes of animals above against the deep blues of The Twilight Zone
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[Music] by day it resides at the very bottom of this Zone at around 1,000 M down where a backdrop of fading light transitions to pitch [Music] black it positions Itself by turning or ratcheting its body so that a second smaller eye peers down into darkness looking for luminous prey dimorphism in the eyes of bilateral animals is rare and yet for the strawberry squid serves as a unique adaptation that allows it to carve out a niche in a place where resources are few and competition is high [Music]
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the boundaries of the ocean zones are not clearcut the Twilight and midnight regions both belong to the aphotic Zone defined as the depths Beyond which less than one% of sunlight penetrates a place often referred to as the dark ocean while some animals are adapted to either the Twilight Zone tailored to a place where light is diminished But Not absent or the midnight zone swallowed by pitch black others are able to span both in such cases it helps to be born with an invisibility
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cloak it's the glass octopus [Music]
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again this one is a male the small hook- likee tip of one tentacle is a modified sexual organ called the hecta cocalis used to pass sperm to the female [Music]
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[Music] a mature female reaching around 45 cm
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[Music]
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her body is speckled with color producing cells called chromatophores that she uses for
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camouflage small muscles can expand to pull open the pigment Sachs darkening her [Music] body it's the same mechanis ISM behind the color changing abilities of many other spilop pods laid bare by a transparent [Music] body in the midnight zone the feeding behaviors of squids and octopuses differs greatly from those of Twilight
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animals above in the misop pelagic life is fastpaced owing to the higher abundance of pre [Music]
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squids here hunt in groups swarming and inking to confuse schools of [Music]
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fish among the largest to do so of the Humbolt squid launching tentacles lined with barbed suckers to grab silvery lantern fish [Music]
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[Music]
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[Music] scenes like this are a nightly occurrence in the Twilight Zone initiated by the slightest changes in ambient light as the sun sets calling forth great swarms of Twilight fish that gather to migrate vertically under the cover of Darkness this phenomenon is one of the only reasons why large active Hunters like Humbolt squid are able to sustain such an energetic
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lifestyle in the bathy pelagic you must be opportunistic to succeed schooling fish are few but sinking organic debris is plentiful Marine snow the scraps left over from the feasts [Music] above in a velvet cloak the vampire squid dangles a long filamentous tentacle covered in adhesive mucus to trap these fine particles [Music] It is Well Suited to a place starved of not just food but oxygen its blood contains a respiratory pigment hemocyanin that has the highest
1:00:08
affinity for oxygen of any known spilop pod thus the vampire squid can reduce competition from other detritivores by occupying the ocean's oxygen minimum zones [Music]
1:00:29
reproducing in the midnight depths can be as challenging as
1:00:36
feeding a mother blackeyed squid hauls a clutch of more than 2,000 eggs through the ocean held in membranous sacks that more than double her length at a depth of 2 km she will carry them for up to 9 months clinging tight with clawed Hooks and Never Letting Go not even to feed it is a once in a lifetime feat and a perilous
1:01:11
one as the eggs mature and the mother weakens her body begins to deteriorate and her muscles waste away unable to Jet Away she is an easy target for predators swimming is a burden yet essential through her movements the mother flushes water through the eggs and oxygenates them if she survives the last few months her final Act of motherly love won't have been in vain her sacrifice bearing new life as the young embark on their own Journeys through the void even so it's unknown just how many
1:01:53
from her clutch of thousands Will Survive to brewed eggs of their [Music] own of the more than 700 spilop pods known to science the blackeyed squid is one of just a few that dare to carry their progeny through the
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dark but they're not the only single [Music]
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parents a barel amphipod or frima carves out a gelatinous protective home from the carcass of a
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salp imagine a squirrel taking over the corpse of a cat she repurposes the body as a mobile home and nurtures her Offspring on the lingering remnants of Flesh some Lai must Brave the dark alone like this benthic Lobster ly or lepto cilis the transparent lval form of [Music] elopomorph one of the most diverse taxonomic groups of fish containing tarpons Bone Fish and all known eels more than 800 species of fish begin their lives this way feeding on sinking particles of marine snow
1:03:30
some remain at this life stage for more than a year before they metamorphose generally the more complex a structure or environment the more biodiversity it's able to support but in deep midw where there are no structures at all and no Solid Surfaces the only form of shelter to be found is other animals large or organisms become drifting arcs lifeboats hosting a troop of smaller animals some are simply hitchhikers the crustations on this blob toop jelly cause little harm or hindrance to the
1:04:08
host yet they benefit by securing a hiding place others are parasites like these amphipods feeding on a
1:04:23
s this Pelican eel Sports a parasitic Copa pod that has wrapped itself around the internal organs and pierced the digestive tract with barbed mouth Parts the two streamer likee structures that trail behind it are strings of
1:04:45
eggs within the bag likee Bell of a shape-shifting deep staria jelly an an Europa sod eats away at its host's delicate skin it must strike a careful balance ensuring it doesn't overindulge or it risks eating itself out of its Hiding
1:05:08
Place deep staria is unusual among jellies belonging to a group known as The alids Many of which lack true tentacles as a result it feeds in an unusual manner engulfing prey before put in the opening of its Bell closed like a drawring bag its digestive system adorns the bell in a mesh-like pattern spread thin to distribute nutrients across its great
1:05:43
[Music]
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surface other alids without tentacles have developed their own feeding strategies the big red jelly tiberon has a bell like a beach ball and stubby finger-like arms lined all over with tiny wart-like concentrations of stinging cells [Music]
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[Music]
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the giant Phantom jelly stigo Medusa gigantia has arms like curtains that can reach 10 m in length draped through the water
1:06:45
column this is the largest of the alits and one of the largest of all known jellyfish in the ocean sometimes found as deep as 6,700 m in the ocean's hadle
1:07:03
[Music]
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Zone the arms are thought to lack stinging cells altogether and are used to sthe and engulf prey within the enormous Bell which it can expand by up to five times
1:07:30
[Music]
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the Phantom jelly participates in another form of ecological
1:07:45
relationship it forms a partnership with a fish called a pelagic brula seen here orienting to the Jelly surfaces
1:08:01
the great Bell of stigo Medusa provides shelter for the fish which in turn removes parasites from the surface of its
1:08:19
protector studies into this relationship have found evidence that this fish can return to its partner if separated at for its body is lined with specialized neuromasts sensory organs highly sensitive to low frequency water movements like those created by the pulsing of the Medusa's Bell in a sense they work together through a mutualistic symbiotic
1:08:51
Association it's a way of life shared by countless pairings throughout the natural world in the ocean depths the collaborative Confluence of life through symbiosis is especially important for the Perils of this great expanse pose a challenge for all however the jellyfish and other gelatinous organisms appear to have mastered this [Music] place they are almost perfectly adapted to a three-dimensional watery world without structure beyond the reach of time one of very few animal groups
1:09:30
helped and not hindered by the lack of complexity in this void the plasticity of their basic morphology means they can grow to extraordinary sizes and take on a multitude of shapes that allow them to move and hunt in ways other more complicated animals cannot the life cycles of deep sea gelatinous organisms are still largely unknown while some survive the expanse by finding shelter in others there is one group that seems to have found the solution to being tiny in a place so
1:10:11
vast siphonophores this is not truly a single organism it is closer to a colony a modular being composed composed of tiny individuals called zoids these are each clones genetically identical but their functions and Anatomy are altered through mutations so that different zoids specialize and take on specific tasks to ensure the survival of all along a central stem these zoids attach confined to set regions where they remain and carry out their role gastro zooids are the feeding polyps
1:10:59
these zoids each dangle a tentacle for capturing and digesting food and nourish the other zoids via the stem nectop fores resemble tiny jellyfish these zoids are the swimming Bells responsible for coordinating the movement of the entire Colony on the tip a gas-filled float called aapor AIDS buoyancy those that bear all three structures are fisin [Music] siphonophores one of three suborders each defined by a distinct body [Music] plan the second are the calicophoron
1:11:41
possessing just two nectors and no newator this is the giant siphonophore prer juia one of the longest animals in the ocean reaching 50 m cects possess a float and a long stem of gastroids but lack swimming Bells resembling little more than frayed rope drifting only at the mercy of the currents [Music]
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[Music]
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[Music] this siphona 4 is about to do something bizarre [Music]
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[Music] it casts off portions of its own [Music] colony splitting its stem in several
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places we don't yet fully understand why it might be dying its structure deteriorating but it seems too purposeful perhaps it's shedding weight to increase its speed and flee perhaps it's cloning itself forming new colonies from the
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[Music]
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fragments the portion that retains the nectome swims [Music]
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away the cast portions can only
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sink their zoids are still alive but without any means of locomotion it's uncertain for how long they will endure whether or not these fragments will grow new nectar fores remains a mystery [Music]
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[Music] in another Colony a great cloud of zoids appear to shed and break away one by one more than likely these shed zoids will die it's thought to be a defense mechanism a reaction to the lights of the underwater robot to distract from the central colony
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[Music]
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gelatinous animals are so successful that they may account for as much as 40% of the biomass of the water column a fact that eluded the scientific Community until recent decades when submersibles and remotely operated vehicles at last allowed us to witness the lives of deep sea animals with our own eyes
1:16:28
[Music] the deep sea is without a doubt alien to us this great void extending far beneath the surface and at the very bottom a place resembling another planet colonized by the bizarre and beautiful but there are parallels with the places we might visit in our everyday lives that just might help us to understand it take for example the forest the cycles of Life Death and nutrients are distilled here the trees in life provide structure and complexity like the corals and
1:17:34
sponges of deep sea mounts or the giant jellies of the midwater all of them a place of shelter for [Music]
1:17:46
life there are layers here too the sunbathed canopy like the ocean's epipelagic Zone the sunlight zone is where the majority of photosynthesis takes place sunlight energy being converted into chemical energy food that through death falls down down down through subsequent layers to nourish those living [Music] underneath very little goes to waste here the rotting Deadwood and leaf litter provides homes and Niche for countless Detroit of ores whose entire evolutionary histories tailored their
1:18:30
form and Physiology to survive on this stuff and in the deep sea just like here it's the Detroit of wars that
1:18:47
Triumph they cycle nutrients through food webs after death they sink and provide a modest Feast to the deep sea floor each year jellyfish alone are thought to sequester 2 billion metric tons of carbon away from the
1:19:11
[Music] atmosphere this is Pago theia it's not a jellyfish or a siphonophore but a CQ cucumber related to starfish and urchins that feeds on Marine
1:19:34
[Music] snow modified tube feet form a ring of feeding tentacles around the mouth and are used to capture and bring debris towards the central orifice it is the only member of its genus and the only known species of truly pelagic C cucumber spending its entire life in the water [Music]
1:20:04
column others spend only part of their life [Music] swimming and nip nastes eximia dubbed The Headless Chicken monster
1:20:24
[Music] not all C cucumbers can swim but the ones that do form a crucial link between the midnight expanse and the ocean bottom
1:20:40
beneath at the bottom of the midwater we reach the intersection of two worlds of the deep where from the formless void at last emerges structure [Music]
1:21:05
the deep sea
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floor a world shaped over millions of years by unique geological processes carving ridges and chasms crafting seen mountain ranges adorned by colorful Gardens flourishing cities of coral and
1:21:42
sponge and on the plains Beyond a great desert where animals work the
1:21:51
sediments a community of Borrowers roers hitchhikers and Bottom
1:22:05
Feeders etching trails in the ancient silt [Music] beds and Scattered boneyards where Great Gatherings of scavengers convene to Feast on the remains of giants
1:22:25
this is a territory of obscurities kept secret and concealed away in the dark at the bottom of the ocean's void the deep sea Plains cover more than half the surface of the Earth hosting their own anthology of tales of Life In The
1:22:53
Deep for
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[Music]
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