For the first time ever, Birch Aquarium at Scripps Institution of Oceanography, UC San Diego has bred and successfully hatched two rare Weedy Seadragons. This is a first for Birch Aquarium, now one of the few aquariums in the world to hatch this unusual fish. The inch-long babies display the characteristic camouflaging appendages of the elaborate adult Weedy Seadragons in miniature, and have already had their first meals of tiny shrimp.
“We are elated to have breeding success with our Weedy Seadragons. This is a momentous event for our team and our seahorse and seadragon breeding program,” said Jennifer Nero Moffatt, the aquarium’s senior director of animal care, science and conservation. “Seadragons are charismatic, sensitive, and require detailed husbandry. We have spent over 25 years working with these animals and love that we have made the next steps to conserve this delicate species.”
Weedy Seadragons are native to southern Australia and Birch Aquarium has had a population on display, and as part of a behind-the-scenes breeding program, since 2012. The Seadragon Breeding Program was created because of the aquarium’s success in breeding other seahorse, or signathid, species. Since 1995 Birch Aquarium has bred thirteen different seahorse species, sharing more than 5,000 juvenile seahorses with other aquariums around the world.
Weedy Seadragons perform elaborate mating displays, where partners spin together snout-to-snout and move up and down in the water column. This “dance” is essential for the successful transfer of eggs from the female onto the male’s tail, where he then fertilizes and hosts the eggs. If mating is successful,, the male will hold the eggs until they hatch about 6 weeks later.
The aquarium hopes to breed the two different kinds of sea dragons so scientists can learn more about the mysterious species. Little is known about them because their populations are so small and in remote areas.
The Weedy Seadragon hatching comes on the heels of the May 2019 opening of Seadragons & Seahorses, Birch Aquarium’s newest permanent exhibition that highlights the husbandry team’s dedicated work and the state-of-the-art research laboratory behind the scenes, part of which is viewable by the public. The exhibition’s aim is to breed seadragons in captivity and help scientists answer basic questions about the species. Currently the most common answer to a seadragon questions is: “We just don’t know.”
“This is an exciting day for Birch Aquarium. Not only are these births a major accomplishment for our talented Husbandry team, but also an exciting step in our commitment to conservation,” said Executive Director Harry Helling.
Once listed as “near threatened” by the ICUN, International Union for the Conservation of Nature, the conservation status of Weedy Seadragons have been downgraded to “least concern” — partially because of the lack of population data. Their remote habitat along Australia’s rugged and underpopulated South Coast makes observation difficult. This isolation, combined with their expert camouflage, makes population counts challenging even for the most experienced seadragon-spotters.
Seadragons and seahorses face challenges in the wild: climate change, warming ocean, compromised habitats, destructive fishing practices like bottom trawling, and unsustainable collection practices for home aquariums and traditional medicine. Captive breeding programs, like that at Birch Aquarium, alleviates pressure on wild populations and contributes to Species Survival Plans (SSPs), as outlined by The Association of Zoos and Aquariums.
In 2013, a male Weedy Seadragon with fertilized eggs on his tail was one of 10 transferred from Monterey Bay Aquarium to Birch Aquarium after the closure of their temporary seadragon exhibit. The seadragons were flown on a private plane from Monterey to Birch Aquarium, where the eggs hatched. This is the first time the Birch Aquarium has had a successful egg transfer, fertilization, and hatching in-house. The aquarium’s husbandry team is diligently monitoring the sensitive baby seadragons and hope for the survival of these fragile newborns.
Since 1995, the Birch Aquarium has bred 13 different seahorse species, sharing more than 5,000 juvenile seahorses with other aquariums around the world.
So far, only the weedy sea dragon has been bred in captivity, and only a handful of times. The Aquarium of the Pacific in Long Beach was the first in the world to breed the weedy sea dragons in 2001. It also is trying to breed leafy sea dragons.
The 18-foot-long tank has 11 weedy sea dragons and three leafy sea dragons, which have never been bred in captivity. The babies with leafy appendages are less than an inch long, and have eaten their first meal of tiny shrimp.
The baby Weedy Seadragons will remain behind-the-scenes and not viewable to the public. All Weedy Seadragons are currently off display due to a yearly habitat deep-cleaning. Their cousins, the more ornate Leafy Seadragons are currently on display in Seadragons & Seahorses.