Dance of the dragons
Step into the new seadragon exhibit at Birch Aquarium, and you’ll see tufts of greenish-brown kelp and sea grass. Wait a moment, and the foliage comes alive, emerging as ornate, delicate creatures that look plucked from a fairy tale.
Native to South Australia, seadragons specialize in camouflage, with decorative appendages that mimic seaweed fronds. The fanciful fish are spreading their fins in a new 5,500-gallon tank this week, as aquarium staff prepared to open a new wing featuring seadragons and several related species. If you’re a “Game of Thrones” fan transfixed by the series’ most ferocious characters, meet their kinder, gentler counterparts.
Seadragons are part of syngnathidae, a family of fish that also includes seahorses, pipefish and other species. They’re all true fish, with pectoral fins, dorsal fins and gills, but they could pass for mythical creatures.
The weedy seadragon is reddish-brown, with kelp-like appendages. Its flashier cousin, the leafy seadragon, is adorned with gossamer yellow fringe. Those aren’t fins, but adaptations that let them camouflage perfectly with the kelp forests, rocky reefs and seagrass beds where they live. Their actual fins are clear, tiny and flickering.
The new aquarium tank houses 11 weedy and three leafy seadragons. Birch experts hope there will soon be more. At nine feet high and 18 feet long, the tank is designed specifically for amorous encounters among its inhabitants.
Birch Aquarium is an international leader in seahorse husbandry, and has shipped 5,000 seahorse babies to other facilities. Seadragons are another story. They’re notoriously hard to breed, and aquariums worldwide count only a handful of births among captive weedy seadragons. Leafies are even trickier; no one has bred them them in captivity.
After years of failed attempts and careful study of the animals, researchers concluded that seadragons require specific light and temperature conditions, as well as space to mate. They engage in elaborate courtship dances that take place up and down the water column, and need vertical room to perform them. That’s where the new, $1 million tank came about. Birch staff are hopeful it will turn the tide for seadragon breeding.
“We’re already seeing some courting behaviors, so it’s really exciting” said Jenn Nero Moffatt, senior director of animal care.
As if on cue, a pair of leafies began swimming in sync, spiraling tightly toward the sandy bottom. Seadragons spin together through the water column in that ritual, until they’re ready to mate. Then the female releases ruby red eggs, and the male accepts them on his tail. Like seahorses, which incubate eggs in a pouch on the male’s belly, seadragon dads tend their eggs until they’re ready to hatch around 40 days later. After that, they’re on their own.
In this case, however, the mating dance was cut short when another female leafy seadragon interrupted. The pair was soon whirling together again, but the next time, a curious weedy butted in, distracting them yet again.
It might seem strange to attribute curiosity to a fish, but throughout the tank the animals were busy inspecting their new environs. One weedy seadragon hovered nearby, poking its head out of a bed of imitation seagrass in what looked like a game of hide and seek. Others chased each other around piles of coral. That frisky, inquisitive behavior enchants aquarists who work with them.
“Ever since I first started my career, dragons have been the focus of my job,” Moffatt said. “Twenty-seven years later, I’m just completely entranced and enthralled. I completely adore these fish. What better ambassador for the other fish you don’t bond with so closely?”
Researchers don’t have good figures for seadragon populations, but note that they face hazards including climate change, pollution and illegal hobby collecting. They live in coastal waters, and hunt mysid shrimp in kelp forests. With a quick snap of their jaw, the dragons suck their prey through their snout, slurping it down whole.
With leaf-like appendages, straw-like snouts and pregnant dads, seadragons check several boxes on the eccentric creature chart. But there’s more. Along with their frilly ornamentation, leafy seadragons boast bright yellow, biofluorescent tails. Other fish that depend on camouflage in order to hide from predators use biofluorescence -- a chemical process by which animals absorb and then re-emit light -- to secretly communicate with each other, said Associate Curator Leslee Matsushige.
“We hypothesize that that’s how they signal to the female that’s where you should put the eggs,” she said. “They may have receptors in their eyes to see that.”
Breeding seadragons in captivity could aid their conservation by enabling researchers to understand their complicated life cycles and breeding rituals, and fine-tune care and husbandry of the animals.
If they start mating, the aquarium will share those young with other facilities, and develop a Seadragon Species Survival Plan through the Association of Zoos and Aquariums, which accredits animal collections and coordinates breeding programs. Aquarium officials anticipate there could be little dragons on the way within six months.
“Hopefully, there will be 100 leafy seadragons in aquariums throughout the world,” Matsushige said.
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