0:00:02 > 0:00:05My name's Steve Backshall, self-confessed shark-obsessed.
0:00:07 > 0:00:09This is Shark Bites.
0:00:10 > 0:00:14This time, we meet the most graceful fish -
0:00:14 > 0:00:16the manta ray.
0:00:16 > 0:00:21These gentle giants glide through our oceans like elegant gymnasts.
0:00:24 > 0:00:27Mantas may look totally different to sharks
0:00:27 > 0:00:30but they're in fact closely related.
0:00:30 > 0:00:32The largest mantas reach up to seven metres
0:00:32 > 0:00:37and use their extended pectoral fins to flap, fly
0:00:37 > 0:00:39and glide through the water.
0:00:39 > 0:00:42But why have they evolved such acrobatic moves?
0:00:42 > 0:00:46A hotspot to find them is Hawaii's Pacific Ocean coast.
0:00:52 > 0:00:57I can already make out some strange shapes in the darkness.
0:00:57 > 0:00:59Oh, my goodness!
0:00:59 > 0:01:01Look at that!
0:01:01 > 0:01:03NARRATION: They may be big, but they're no threat to me.
0:01:03 > 0:01:05Whoa!
0:01:05 > 0:01:07NARRATION: Unlike their distant cousins, stingrays,
0:01:07 > 0:01:09there's no sting in the tail.
0:01:09 > 0:01:11What a phenomenal beast!
0:01:11 > 0:01:14And they're everywhere! Oh, my goodness!
0:01:14 > 0:01:16It nearly took my head off!
0:01:18 > 0:01:22Their sleek physique means they're hydrodynamic, enabling them
0:01:22 > 0:01:27to cut through the water with ease, somersaulting like gymnasts.
0:01:27 > 0:01:30But to find out how they pull off these acrobatic moves
0:01:30 > 0:01:33we need to get under their skin.
0:01:35 > 0:01:39Like sharks, manta rays have a lightweight, flexible skeleton.
0:01:39 > 0:01:42Instead of bone, it's composed of cartilage,
0:01:42 > 0:01:45the same substance that's found in our ears.
0:01:45 > 0:01:48One difference from sharks is their huge pectoral fins
0:01:48 > 0:01:52that have evolved into these triangular wings.
0:01:52 > 0:01:56While sharks use their pectoral fins for lift and steering,
0:01:56 > 0:01:59the manta ray uses them to propel itself forward.
0:01:59 > 0:02:03Just like a bird, it flaps these triangular wings,
0:02:03 > 0:02:07creating a water whirlpool that gives it forward momentum,
0:02:07 > 0:02:09making swimming appear effortless
0:02:09 > 0:02:11and giving them their graceful moves.
0:02:13 > 0:02:18And it's these graceful moves that allow them to feed so efficiently.
0:02:18 > 0:02:20As they shoot towards you,
0:02:20 > 0:02:24you're gazing down into this vast, open mouth
0:02:24 > 0:02:26as it sucks up food.
0:02:27 > 0:02:31Like some sharks, mantas are filter feeders,
0:02:31 > 0:02:36feeding on tiny microscopic plants and creatures called zooplankton.
0:02:37 > 0:02:41Performing these dizzying displays of balletic barrel rolls,
0:02:41 > 0:02:45they make the most of these dense pockets of petite prey.
0:02:46 > 0:02:51The manta ray - with its hydrodynamic design, flexible frame
0:02:51 > 0:02:54and powerful wings to propel it forward,
0:02:54 > 0:02:58it is certainly the most graceful fish in our seas.