Four weedy seadragons at the Columbus Zoo and Aquarium are carrying eggs. CREDIT: Columbus Zoo and AquariumFour weedy seadragons at the Columbus Zoo and Aquarium are carrying eggs. CREDIT: Columbus Zoo and AquariumWeedy seadragons are bony seahorse relatives native to Australia’s coasts with small heads, long tails, and leaf-like limbs. Amanda CarberryPart of the complexity comes from the weedy seadragons’ intricate mating ritual. Weedy seadragons are related to seahorses and can grow up to 18 inches long.