The children's book is much-loved around the world and is also a common way of complimenting someone too YOU pick up all sorts of strange bits of slang and phrases while watching Love Island.

After Rainbow Fish dutifully relinquishes a shiny scale to a grateful swimmer ... routes made possible by international capitalism (the book has been translated into more than 50 languages ...

I'll give you a quick rundown of the book in case you've never opened it: basically, there's this fish with eye-catching, unique scales, which sets him apart from other fish in the sea.

Fish have developed this ability over millions of years of evolution, embodied in their shiny scales. And now, a new study – published on Monday in Nature Photonics – suggests this natural ...