We have a perennial fascination with sharks. Portrayed in the media and popular culture as killing machines, we are awed by their power and strength. But the shark is so much more – a marvel of the sea, they have evolved over 450 million years into over 500 species, from the bioluminescent kitefin to the tiny dwarf lantern shark, the sociable lemon shark to the blue shark, which can birth up to 100 pups in one litter.