0:00:02 > 0:00:03My name's Steve Backshall -
0:00:03 > 0:00:06self-confessed shark obsessed.
0:00:06 > 0:00:08This is Shark Bites.
0:00:10 > 0:00:13This time we meet a shark that is super speedy.
0:00:15 > 0:00:16The mako shark.
0:00:16 > 0:00:19This toothy torpedo can clock speeds
0:00:19 > 0:00:25of 50kph, making it the fastest shark on the planet.
0:00:26 > 0:00:29Living out in the open ocean, and with a fondness
0:00:29 > 0:00:34for fast-swimming fish like tuna, the makos can't hang around.
0:00:34 > 0:00:37They need to move quickly.
0:00:37 > 0:00:40But how have they evolved to reach such speeds?
0:00:40 > 0:00:43San Diego, off California's Pacific coast,
0:00:43 > 0:00:46is the perfect place to see these lightning-quick sharks.
0:00:48 > 0:00:50As an idea of how fast they can go,
0:00:50 > 0:00:54right now our boat's doing about 35kph.
0:00:54 > 0:00:56Well, the mako does 50
0:00:56 > 0:00:59and could cruise straight past us as if we were standing still.
0:01:01 > 0:01:04Which makes them incredibly difficult to pin down.
0:01:07 > 0:01:09I think we might have something.
0:01:09 > 0:01:12Just a fin came up alongside the bait.
0:01:12 > 0:01:14Looks like he didn't see it clearly enough to say
0:01:14 > 0:01:16even that it was a shark, let alone that it was a mako.
0:01:16 > 0:01:19There was only one way to find out.
0:01:20 > 0:01:21Mako shark.
0:01:21 > 0:01:24It's coming right at him, coming right at him.
0:01:24 > 0:01:28The two of them are patrolling around us.
0:01:28 > 0:01:30One second they're there, the next second they're gone.
0:01:30 > 0:01:32They just disappear into the blue.
0:01:32 > 0:01:36As the pair of them circle around me, I'm completely blown away
0:01:36 > 0:01:40by the ease at which they explode into these serious speeds.
0:01:40 > 0:01:42I don't think I've ever seen anything like it.
0:01:42 > 0:01:44It just always looks like it's on edge,
0:01:44 > 0:01:48always looks like it's ready to burst out into speed.
0:01:48 > 0:01:50So, what is their secret?
0:01:53 > 0:01:56Not only are these sharks superbly streamlined,
0:01:56 > 0:01:59with their cylindrical shape tapering at both ends,
0:01:59 > 0:02:02the tail's crescent shaped, perfect for propulsion,
0:02:02 > 0:02:06and the short fins help reduce drag.
0:02:06 > 0:02:10But it's inside this shark that the magic really happens.
0:02:10 > 0:02:14Most sharks are ectothermic - that means cold-blooded.
0:02:14 > 0:02:18The temperature of their blood is the same as the water around them.
0:02:18 > 0:02:20But mako sharks are endothermic.
0:02:20 > 0:02:23They can generate their own heat from within.
0:02:23 > 0:02:26The warmth that's created in their muscles by activities
0:02:26 > 0:02:30like swimming and digesting their food can be retained
0:02:30 > 0:02:34in vital areas like the eyes, the brain, the digestive tract
0:02:34 > 0:02:36and the swimming muscles.
0:02:38 > 0:02:40A perfect predatory superpower -
0:02:40 > 0:02:45that's clear to see in these mighty marine torpedoes.
0:02:47 > 0:02:49So, with its staggering speeds,
0:02:49 > 0:02:51ingenious internal heating,
0:02:51 > 0:02:54and exceptionally explosive power,
0:02:54 > 0:02:58the mako is without doubt one super speedy shark.