Seahorses are little fish with horse-shaped heads, curly tails, and crowns that scientists think are actually unique to each individual, like fingerprints. They’re also the only animals on Earth where it’s the male who gets pregnant.
When seahorses mate, the female uses a tube to deposit her eggs into a special pouch on the male’s belly. He fertilizes them inside, and the pouch acts like a tiny aquarium - keeping the developing babies safe and feeding them through the pouch walls.
A few weeks later, the father has full-blown contractions and squeezes out hundreds - sometimes thousands - of tiny baby seahorses. Then it’s over: most seahorse dads are ready to do it again within a day or two. In their daily greeting dance with their partner, mated pairs change color, hold tails, and pirouette together for hours.
