This video says about itself:
22 April 2016
Jonathan explores cleaning stations on the reef, where animals get cleaned of parasites and infection by other animals. Some examples shown are anemones and anemonefish (clownfish), wrasses, shrimp, manta rays, moray eels, Goliath groupers, sea turtles and barracuda. This episode was filmed in many locations such as Malaysia, the Philippines, Yap, Australia’s Great Barrier Reef and the Caribbean.
It’s a mystery how cleaner shrimp partner with would-be fish predators — sometimes even climbing in their mouths — without getting eaten. A new study reveals how the shrimp convinces fish not to eat them, and the fish conveys that it’s a friend and not a foe: here.