Original subtitles

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NARRATOR: WHEN YOU SEE THIS SYMBOL, YOU KNOW YOU'RE WATCHING

TELEVISION THAT IS EDUCATIONAL AND INFORMATIONAL.

THE MORE YOU KNOW ON NBC.

DYLAN: HI, EVERYBODY, I'M DYLAN DREYER.

WELCOME TO "EARTH ODYSSEY".

TODAY, WE DIVE INTO THE UNBELIEVABLE UNDERWATER WORLDS

OF THE ANIMAL KINGDOM.

WE'LL DISCOVER WHY THESE HUMPBACK WHALES ARE TAKING A

BUBBLE BATH.

PLUS, THESE DOLPHINS MUDDY UP THE WATER TO HUNT THEIR PREY.

AND LATER, WE DISCOVER WHAT'S SKIMMING ACROSS THE SURFACE OF

ONE OF THE WORLD'S LARGEST MANMADE LAKES.

BUT FIRST, YOU WON'T BELIEVE THE SIZE OF THESE ANCIENT

AQUATIC ANIMALS.

[MUSIC]

DYLAN: OCEANS COVER MORE THAN 70 PERCENT OF THE EARTH'S

SURFACE, BUT HUMANS HAVE EXPLORED LESS THAN FIVE PERCENT.

THE VASTNESS AND DEPTHS OF OUR OCEANS MAKE IT ALL BUT

IMPOSSIBLE TO SEE EVERYTHING.

HOWEVER, WHAT WE HAVE EXPLORED REVEALS AN UNPARALLELED

DIVERSITY OF LIFE, EVEN IN PLACES YOU'D LEAST EXPECT, LIKE

OUR FIRST STOP, EGYPT, WHERE A HIDDEN UNDERWATER EUTOPIA IS

TEEMING WITH LIFE.

THE OCEAN.

FULL OF WISDOM, WONDER, AND YOU GUESSED IT, WATER.

IT'S ESTIMATED THAT MORE THAN 300 QUINTILLION GALLONS OF WATER

ARE ON PLANET EARTH.

AND IN EVERY REGION, THERE ARE MYTHS, CREATURES, AND EVEN

TRADITIONS THAT TAKE PLACE IN THESE UNDERWATER WORLDS.

LIKE IN ANCIENT EGYPT, WHERE THEY OFFERED EELS TO ATUM,

THE CREATOR GOD.

THEIR MUMMIFIED REMAINS WERE THEN BURIED IN BRONZE BOXES.

GIANT MORAY EELS CAN GROW TO ABOUT NINE FEET LONG.

THIS OPENING AND CLOSING OF THE MOUTH ENSURES A STEADY FLOW OF

WATER ACROSS ITS GILLS.

MORAYS USUALLY HUNT AT NIGHT, USING THEIR EXCELLENT SENSE OF

SMELL TO TRACK DOWN AND AMBUSH PREY.

[MUSIC]

DYLAN: GARDEN EELS LIVE IN COLONIES OF UP TO

1,000 INDIVIDUALS.

GROWING UP TO MORE THAN A FOOT LONG, THEY FEED ON PLANKTON AND

ANY SMALL FISH THAT HAPPEN TO PASS BY.

USING THEIR TAILS, THEY BURROW INTO THE SEABED.

THIS BECOMES THE PERMANENT HOME WHICH THEY NEVER LEAVE.

AS WELL AS PROVIDING A SOLID ANCHOR, THESE HOLES PROVIDE THE

PERFECT RETREAT FROM PREDATORS.

THIS GIANT ACTUALLY POSES NO THREAT TO GARDEN EELS.

WHALE SHARKS ARE THE LARGEST FISH IN THE WORLD.

THEY CAN GROW MORE THAN 40 FEET LONG AND WEIGH UP TO

41,000 POUNDS.

THIS IS ABOUT THE SIZE OF A SCHOOL BUS AND THE WEIGHT OF

MORE THAN FIVE AFRICAN ELEPHANTS.

ON AVERAGE, WHALE SHARKS LIVE TO BE 70 YEARS OLD, BUT SOME HAVE

BEEN KNOWN TO BE WELL OVER 100.

THEY ARE A DOCILE SPECIES AND EVEN ALLOW SMALLER SWIMMERS TO

HITCH A RIDE ON THEIR BACKS.

BUT THAT DOESN'T MEAN THEY DON'T POSE A THREAT TO SOME ANIMALS.

DWARFING EVERYTHING IN THEIR WAY, THEY SURVIVE ON SOME OF THE

SMALLEST ORGANISMS IN THE OCEAN.

THEY CAN SIFT MORE THAN 1,500 GALLONS OF WATER AN HOUR.

FINE FILTERS, ALSO KNOWN AS GILL RAKERS, TRAP ANY ORGANISM OVER

TWO MILLIMETERS WIDE.

IN ORDER TO EAT, THEY WILL OPEN THEIR MOUTHS, JUT OUT THEIR

JAWS, AND USE 20 FILTER PADS TO REMOVE THEIR FOOD FROM THE

WATER.

THIS TECHNIQUE IS CALLED CROSSFLOW FILTRATION, AND IT'S

ALSO SEEN IN OTHER AQUATIC ANIMALS, LIKE THE BALEEN WHALE.

MOST SPECIES OF SHARK WAVE THEIR TAILS TO PROPEL THEMSELVES.

HOWEVER, WHALE SHARKS ARE UNIQUE IN MOVING THEIR ENTIRE BODIES

FROM SIDE TO SIDE.

THEY REMAIN CLOSE TO THE SURFACE AND THEIR TOP SPEED IS A MODEST

THREE MILES PER HOUR.

BUT DESPITE THEIR SLOW SPEED, THESE FISH ARE MASTER MIGRATORS.

THEY WILL TRAVEL FOR MILES TO WARMER WATERS,

WHERE PLANKTON ARE BOUNTIFUL.

WITH THEIR PASSIVE NATURE AND REMITTED SELF-DEFENSE

MECHANISMS, WHALE SHARKS ARE A TRUE TESTAMENT TO THE POWER THAT

SIZE CAN HAVE IN THE WILD.

COMING UP, THESE MANTA RAYS CAN'T HELP BUT MAKE FRIENDS

WHEREVER THEY GO.

AND LATER, WE HEAD TO LAKE NASSER, HOME TO ONE OF THE

PLANET'S LARGEST AND MOST DANGEROUS PREDATORS.

BUT FIRST, WE DIVE RIGHT IN TO DOLPHIN DINNERTIME.

ALL OF THIS AND MUCH MORE COMING UP ON "EARTH ODYSSEY".

[MUSIC]

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NARRATOR: WE NOW RETURN TO THE MORE YOU KNOW ON NBC.

DYLAN: HERE IN FLORIDA, THESE DOLPHINS HAVE USED THEIR VAST

INTELLIGENCE TO DEVISE A NEW WAY OF CATCHING FISH.

TAKING UP A POSITION DOWNSTREAM, ONE OF THE DOLPHINS USES HER

TAIL TO WHIP UP A WALL OF SILT FROM THE SEABED.

THE OTHER DOLPHINS ARE WAITING PATIENTLY, UNABLE TO SEE THROUGH

THE MUDDIED WATER, THE FISH ARE FORCED TO GO OVER IT.

STRAIGHT INTO THE PATH OF THE WAITING DOLPHINS.

[MUSIC]

DYLAN: IT'S AN INGENIOUS TECHNIQUE, LIKELY PASSED DOWN

THROUGH GENERATIONS.

TAUGHT BY THE ADULTS TO THEIR OFFSPRING.

[MUSIC]

DYLAN: THIS ADVANCED LEVEL OF PROBLEM-SOLVING AND TEAMWORK

CLEARLY DEMONSTRATE THE DOLPHIN'S INCREDIBLE

INTELLIGENCE AND THE DESIRE TO MAKE HUNTING MORE EFFICIENT IS A

TRADEMARK OF ANY ANIMAL'S BRAINPOWER.

WHEN IT COMES TO EFFICIENT, COORDINATED HUNTING, DOLPHINS

AREN'T THE ONLY MARINE MAMMALS THAT HAVE DEVISED AN INGENIOUS

METHOD TO CORRAL THEIR PREY.

HUMPBACK WHALES ARE BIG AND THEY ARE ALSO CLEVER.

IN FACT, THE WAY THEY HUNT TAKES ANIMAL INTELLIGENCE

TO THE NEXT LEVEL.

DESPITE WEIGHING UP TO 40 TONS, HUMPBACKS ONLY EAT KRILL AND

SMALL FISH.

IN ORDER TO CATCH ENOUGH PREY, THESE HIGHLY INTELLIGENT WHALES

HAVE DEVELOPED A UNIQUE HUNTING METHOD CALLED BUBBLE NETTING.

FOR THE BUBBLE NET TO WORK, THE WHALES MUST USE HIGHLY DETAILED

VOCALIZATIONS TO COORDINATE THE ENTIRE POD.

ONCE A SHOAL IS LOCATED, THE LEAD WHALE DIVES DEEP BELOW THE

FISH AND THEN EXHALES.

DRIVING THE SHOAL TOWARDS THE SURFACE.

THEN WORKING AS A TEAM, THE REST OF THE POD SURROUNDS THE SHOAL.

BLOWING BUBBLES AND SOUNDING LOUD CALLS TO DISORIENT THE

FISH.

THIS WALL OF SOUND AND BUBBLES PREVENTS THE FISH FROM ESCAPING.

ONCE THE BUBBLE NET IS IN PLACE, THE WHALES THEN DIVE, SURGING UP

FROM BELOW.

THEIR ENORMOUS JAWS ENGULFING THE HELPLESS FISH.

[MUSIC]

DYLAN: USING THEIR INTELLIGENCE AND COMPLEX LANGUAGE, THESE

WHALES WILL FEAST LIKE THIS ALL SUMMER LONG.

[MUSIC]

DYLAN: BEFORE RETURNING TO THE WARMER EQUATORIAL WATERS,

TO BREED AND GIVE BIRTH TO THE NEXT GENERATION.

COMING UP, WE HEAD TO AFRICA TO SEE AN ANCIENT EGYPTIAN.

THE NILE CROCODILE.

PLUS, THESE MAJESTICAL GIANT RAYS DO A DANCE IN THE DEEP,

COMING UP ON "EARTH ODYSSEY".

[MUSIC]

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NARRATOR: WE NOW RETURN TO THE MORE YOU KNOW ON NBC.

DYLAN: THE NILE CROCODILE IS ONE OF THE MOST INFAMOUS

REPTILES IN THE WORLD.

AT THE TOP OF THE AFRICAN AQUATIC FOOD CHAIN, IT HAS ONE

OF THE STRONGEST BITES IN THE ANIMAL KINGDOM.

AND WHILE IT'S EASY FOR US TO BE IN AWE OF THE STRENGTH OF THEIR

JAW, IT'S THE REASON WHY THEIR PREY SHOULD STAY AWAY.

WHICH CAN BE TOUGH TO DO IF YOU'RE A FISH THAT LIVES IN THE

BELLY OF THE BEAST, LAKE NASSER.

TAKE A LOOK.

ALTHOUGH THE RIVER NILE HAS OFFERED A LIFELINE TO EGYPT'S

RESIDENTS FOR THOUSANDS OF YEARS, A MORE RECENT FEATURE HAS

BECOME A HAVEN FOR THE REGION'S ABUNDANT WILDLIFE.

AT ALMOST 350 MILES LONG AND MORE THAN 20 MILES WIDE, LAKE

NASSER IS ONE OF THE LARGEST MANMADE LAKES IN THE WORLD.

AROUND 50 YEARS AGO, THE RIVER NILE WAS DAMMED TO CREATE THIS

ENORMOUS RESERVOIR.

THIS BROUGHT MEND TO THE OFTEN-UNPREDICTABLE FLOOD LEVELS

FURTHER DOWNSTREAM.

ANCIENT EGYPTIANS BELIEVED THE ANNUAL DELUGE OF FAST-FLOWING

WATER WAS A GIFT FROM THE GODS.

THEY HAD NO IDEA ITS ORIGIN LIES ALMOST 2,000 MILES

FARTHER SOUTH.

APPROXIMATELY 90 PERCENT OF THE NILE'S WATER ORIGINATES FROM THE

ETHIOPIAN HIGHLANDS, WHICH RECEIVE ABOUT

SIX AND A HALF FEET OF RAIN EACH YEAR.

IT'S ALONG THESE TINY TRIBUTARIES THAT FERTILE SOILS

ARE WASHED DOWNSTREAM, BEFORE ENTERING THE LONGEST RIVER ON

THE PLANET.

TODAY, THE DAMMING OF THE NILE PREVENTS THE SILK-RICH WATER

FROM TRAVELING FARTHER DOWNSTREAM.

INSTEAD, LAKE NASSER AND ITS WILDLIFE BENEFIT FROM THE FOUR

MILLION TONS OF SEDIMENT DEPOSITED HERE EACH YEAR.

ONE CREATURE BENEFITS FROM LAKE NASSER'S SHORELINE

MORE THAN MOST.

NILE CROCODILES DON'T REACH MATURITY UNTIL AROUND

TEN YEARS OLD.

THIS FEMALE'S RELATIONSHIP WITH A MALE TWO MONTHS AGO

WAS A SUCCESS.

THE LAKE'S SANDY SHORE IS PERFECT FOR EXCAVATING HER NEST.

[MUSIC]

DYLAN: AFTER REACHING AROUND A FOOT AND A HALF DEEP,

SHE STARTS TO LAY.

APPROXIMATELY 50 EGGS ARE DEPOSITED INTO THE

NESTING CHAMBER.

FINALLY, THEY'RE COVERED WITH SAND.

IT'LL BE THREE MONTHS UNTIL HER YOUNGSTERS ARE READY TO HATCH.

UNTIL THEN, SHE'LL REMAIN CLOSE, FIERCELY GUARDING THE SITE.

COMING UP, DINNER WITH FRIENDS.

THESE GIANTS TRULY KNOW HOW TO PICK WHO TO HANG OUT WITH.

[MUSIC]

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NARRATOR: WE NOW RETURN TO THE MORE YOU KNOW ON NBC.

DYLAN: THE ZANZIBAR ISLAND CHAIN OFF THE COAST OF AFRICA

HIDES MANY UNDERWATER GIANTS.

AND OF THE 400 OR SO SPECIES OF RAY, THE MANTA IS THE LARGEST.

THESE ALIEN-LOOKING CREATURES CAN GROW UP TO AN INCREDIBLE

22 FEET ACROSS AND WEIGH AS MUCH AS 4,000 POUNDS.

THEY LEAD SOLITARY LIVES AND ONLY COME TOGETHER IN LARGE

NUMBERS UNDER CERTAIN CONDITIONS.

THESE MANTA RAYS HAVE TRAVELED FAR TO THIS SECTION OF REEF FOR

A SPECIAL SERVICE.

THIS CLEANING STATION PROVIDES THE OPPORTUNITY FOR

A GOOD ONCE OVER FROM ATTENTIVE CLEANER FISH.

FLASHES OF BLUE AND YELLOW ADVERTISE THEIR PRESENCE.

THE CLIENTS HAPPILY FLOOD IN.

BUT BEFORE THE MANTA RAYS TAKE UP THIS SERVICE, THEY NEED TO

FORM A LINE.

INDIVIDUALS SIZE ONE ANOTHER UP BY SWIMMING PARALLEL TO THE

REEF.

ONCE A HIERARCHY IS ESTABLISHED, THEY TAKE TURNS SWOOPING INTO

THE STATION.

EACH SPECIES OF CLEANER FISH NIBBLES A DIFFERENT SECTION TO

REDUCE COMPETITION.

THIS MUTUALLY BENEFICIAL RELATIONSHIP PROVIDES THE FISH

WITH A STEADY SUPPLY OF FOOD AND ENSURES THE MANTA'S SKIN IS FREE

OF DEAD CELLS AND PARASITES.

CLEANING SESSIONS CAN LAST UP TO THREE HOURS AND ONCE THOROUGHLY

SCRUBBED, THE MANTA RAYS HEAD BACK INTO THE DEEP.

UNLIKE MANY OF THEIR SHARK COUSINS, THESE GRACEFUL GIANTS

POSE NO THREAT TO OTHER FISH.

MANTA RAYS ARE FILTER FEEDERS AND WHEN PLANKTON BLOOMS,

EVERYONE JOINS THE FEEDING FRENZY.

FILTERING LARGE VOLUMES OF WATER, THEY FUNNEL THESE

MINIATURE PREY INTO THEIR GAPING MOUTHS.

A SINGLE MANTA CAN CONSUME UP TO 37 POUNDS OF PLANKTON A DAY.

[MUSIC]

DYLAN: THESE GIANTS THAT SWIM IN THE OCEAN GIVE ZANZIBAR THE

WILD CHARACTER THAT MAKES IT ONE OF THE MOST INTERESTING AND

BEAUTIFUL PLACES ON EARTH.

WE'RE SO GLAD YOU COULD COME ALONG FOR AN ADVENTURE BENEATH

THE WAVES TO SEE SOME OF EARTH'S MOST AMAZING AQUATIC ANIMALS.

THESE UNDERWATER WORLDS ARE HOME TO SO MANY ANIMAL SPECIES THAT

HAVE LEARNED TO THRIVE WHERE IT'S WET AND WILD.

THANKS FOR JOINING US AND WE'LL SEE YOU ON THE NEXT EPISODE OF

"EARTH ODYSSEY".

[MUSIC]