Move over, gender norms: the Hedgehog Seahorse is here to shake up convention. These spiky swimmers flip the script on parenting, with male seahorses getting "pregnant" and giving birth to tiny, prickly offspring. You'll find these progressive parents hanging out in reefs and on sandy ocean floors from India and Sri Lanka to Taiwan and northern Australia. They're probably discussing the challenges of seahorse fatherhood to anyone who will listen - or at least, anyone who can see through their excellent camouflage.

Growing up to 12.5 centimetres long, hedgehog seahorses sport a distinctive low coronet and long snout. As members of the Syngnathidae family, they're related to pipefish and seadragons. And while they may look tough, these little swimmers are actually quite vulnerable to habitat loss and overfishing.