Found in the coastal waters of the Indo-Pacific, the Rainbow Belly Pipefish is a close relative of seahorses and shares their most famous trait — it is the male that carries and gives birth to the young, brooding eggs in a pouch along his belly.

The female's vivid, sail-like belly membrane can be hidden or unfurled like a flag as a display, making her one of the few fish where the female actively courts the male!