The ocean’s largest mystery – why has no one seen a whale shark give birth?

Figuring it out is paramount to save these gentle giants from extinction. "Here is the biggest fish in the oceans, it's almost certainly the biggest shark, and what is known about their reproductive behaviour is almost nothing." In the Guardian, Ashifa Kassam examines how a world-first ultrasound and chance sightings of potential mating rituals could drastically improve our knowledge of how whale sharks reproduce.