LA JOLLA, California (AP) — At first glance, it looks like a branch of kelp, but then an eye moves among its leafy appendages, and ridges of tiny, translucent fins start to flutter, sending the creature gliding through the water like something from a fairy tale.

A Southern California aquarium has built what is believed to be one of the world’s largest habitats for the surreal sea dragons, whose native populations off Australia are threatened by pollution, warming oceans and the illegal pet and alternative medicine trades.

The Birch Aquarium at the Scripps Institution of Oceanography at the University of California San Diego hopes the exhibit, which opened this month, will lead to the leafy sea dragon, the lesser-known cousin of the seahorse, being bred for the first time in captivity.

“It literally just looked like a piece of kelp,” said Steven Kowal, 25, who was visiting San Diego from Greensboro, North Carolina, and took time to see the exhibit. “It was crazy to me that it was, like, actually living and swimming around, so that’s cool. I’ve never seen anything like that.”

That’s a common reaction.

“They look like something out of this world,” said Leslee Matsushige, the aquarium’s associate curator, who noted the sea dragons’ amazing ability to camouflage themselves. “When people see them move, you hear them say, ‘What? That’s alive? Wow! That’s crazy.’”