One of the most elegant courtship rituals in the animal kingdom has been captured on film by a BBC crew.
The dance of the weedy sea dragon takes place every year in the shallow seas off the coast of Australia.
During the ghostly dance, two beautifully odd-looking fish mirror each other's every movement.
At the end of the ritual, the male fish is the one to get pregnant, giving birth two months later, a process the BBC crew filmed for the first time.
The "dance of a sea dragon" is broadcast within the Fish episode of the BBC series
at 2100GMT on BBC One on Monday 2 November.