0:00:02 > 0:00:03My name's Steve Backshall.
0:00:03 > 0:00:06Self-confessed shark obsessed.
0:00:06 > 0:00:09This is Shark Bites.
0:00:10 > 0:00:16Meet the most colossal shark of all - the mighty whale shark.
0:00:16 > 0:00:18Not only is this the biggest shark,
0:00:18 > 0:00:21but the biggest fish in the whole world.
0:00:23 > 0:00:27Reaching record lengths of over 18 metres, which is
0:00:27 > 0:00:29longer than a double-decker bus,
0:00:29 > 0:00:32they can weigh in at a mighty 30 tonnes.
0:00:34 > 0:00:38So, how so they satisfy their equally astronomic appetites?
0:00:38 > 0:00:41Mozambique on the east coast of Africa is the perfect
0:00:41 > 0:00:42place to find them.
0:00:46 > 0:00:47Whale shark.
0:00:47 > 0:00:51Wow, look at the size of that! Huge!
0:00:51 > 0:00:54- Right, we looking good? - OK, I reckon. Steve in.
0:01:00 > 0:01:06Is there anything more majestic in the world's oceans?
0:01:08 > 0:01:10And just as I was revelling in its beauty,
0:01:10 > 0:01:13it put on a spectacular show.
0:01:13 > 0:01:16HE LAUGHS
0:01:16 > 0:01:18He's feeding!
0:01:18 > 0:01:24When he's eating like this, you can see that this is actually a hunter.
0:01:25 > 0:01:28But what's on the menu may well surprise you.
0:01:31 > 0:01:35This gigantic creature consumes tens of thousands of tiny,
0:01:35 > 0:01:37microscopic plankton.
0:01:37 > 0:01:41Minute plants and animals that float in the water,
0:01:41 > 0:01:43but are hardly visible to the eye.
0:01:46 > 0:01:47For an animal of this size,
0:01:47 > 0:01:53constantly chasing shoals of feisty fish would use far too much energy.
0:01:54 > 0:01:59So instead, these colossal creatures cruise around, making the most
0:01:59 > 0:02:03of this super-abundant food supply with their mammoth mouths.
0:02:07 > 0:02:09Whale sharks are what are known as filter feeders.
0:02:09 > 0:02:12Water passes into their enormous mouths
0:02:12 > 0:02:15before heading over 20 filtering pads
0:02:15 > 0:02:18which separate their plankton prey from the water.
0:02:18 > 0:02:20The water continues down and out through the gills,
0:02:20 > 0:02:24while the heavier plankton concentrates into a big ball
0:02:24 > 0:02:26and is swallowed down into the stomach.
0:02:28 > 0:02:33And this plankton soup makes the perfect shark supper.
0:02:34 > 0:02:40You know, it's such a huge creature, it's one of the wonders
0:02:40 > 0:02:44of nature that all the things it feeds on are so tiny.
0:02:47 > 0:02:51The whale shark, with its surprising supper, its mega mouth and
0:02:51 > 0:02:57gargantuan size is, without doubt, the most colossal shark of all.