What did one dolphin say to the other dolphin? We can't know for sure, but whatever the joke is, these beautiful creatures look to be sharing a big laugh. They are playing one of their favourite games ...

How do you make a dolphin laugh? Tell it a joke or pull a funny face, perhaps? Nope. If this footage is anything to go by, a spot of gymnastics will do the trick. The minute-long clip, titled 'Girl ...