After years of trying, a Southern California aquarium has two very tiny — and very rare — bundles of joy.

Two weedy seadragons recently hatched at in La Jolla, Calif. The delicate creatures resemble bits of seaweed and are distant cousins of the seahorse. And they're notoriously difficult to breed.

Birch announced the news on Thursday and is now one of only a few aquariums worldwide to get the finicky animal to reproduce in captivity. Jennifer Nero Moffatt, the aquarium's senior director of animal care, science and conservation, called it a "momentous occasion."

"Seadragons are charismatic, sensitive, and require detailed husbandry," Moffatt said in a statement. "We have spent over 25 years working with these animals and love that we have made the next steps to conserve this delicate species."

Birch Aquarium says it has bred 13 types of seahorses since 1995 and started its weedy seadragon program because of that track record of success.

The aquarium says the inch-long babies are already feeding on tiny shrimp. They'll grow to about 18 inches.

It's not clear whether the newly hatched little ones are male or female — and the Birch says it likely won't know until they reach sexual maturity in a few years.

The weedy seadragon, or Phyllopteryx taeniolatus, is native to waters off Australia. They have long, thin snouts and small fins that propel them through the water, though they often drift like seaweed.

As part of their mating rituals, the seadragons do a spinning dance, snout to snout — that's how they transfer eggs from the female to the males.

Like other seahorses, the males carry the eggs after the females deposit them on the male's spongy tail. The eggs incubate, then hatch in about six weeks.

/ Courtesy of Birch Aquarium at Scripps Institution of Oceanography via AP

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Courtesy of Birch Aquarium at Scripps Institution of Oceanography via AP

The fish was once a "near-threatened" species but has since been designated as "least concern" by the International Union for Conservation of Nature and Natural Resources. That's partially because there is little data on the population, according to the Birch Aquarium.

The creatures are especially hard to track because of their rugged and remote habitat along Australia's southern coast — and weedy seadragons are good at camouflage.

But warming oceans and destructive fishing practices threaten their habitat, creating a greater need for aquariums to breed and study the rare animals, the aquarium said.

But if you're in Southern California and want to get a glimpse at the teeny-tiny seadragons, don't get your hopes up. The aquarium says they'll stay behind-the-scenes and out of the public eye for now.

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