The aquarium's sea dragon has about 70 fertilized eggs — which look like small red grapes — attached to his tail. He is expected to give birth in early to mid-July, said Kerry Gladish, a biologist at the aquarium.
Sea dragons, sea horses and pipe fish are the only species where the male carries the eggs, Gladish said. Sea dragon pregnancies are rare because researchers don't know what gets them in the mood to mate.
"We know there's something biologically or environmentally that triggers them to want to reproduce, but in the aquarium world, we're not sure what that is," Gladish said.
The aquarium recently changed the lighting and thinned out the plants in the sea dragons' tank to give them room to court each other.
The aquarium has seven of the 18-inch sea dragons, which resemble Dr. Seuss characters with long aardvark-like snouts, colorful sea horse bodies and multiple paddle-like fins.
During mating, the female lays dozens of eggs and then transfers them to the male's tail.
In the wild, the survival rate for sea dragon babies is low, but in captivity it's about 60 percent, Gladish said. The fish is on the International Union for Conservation of Nature's list of threatened species, mostly because of pollution and population growth in its native Australia.
Only about 50 aquariums worldwide have sea dragons.