Baby Seadragons at Birch Aquarium: Leslee’s Update

By Leslee Matsushige, Birch Aquarium co-curator


In late September, the first brood hatched from Birch Aquarium’s Seadragon Propagation Program. Learn more about the program and find out how the aquarium acquired the male weedy with eggs on its tail.

During this critical time in their young lives, the baby seadragons are kept in our special seadragon breeding center. Since we know that people are very excited about these little ones, here’s an update on their development:

The baby weedy seadragons were approximately 2 cm (or 3/4″) in length when they hatched. One of the babies hatched a week before the other six, and since we could see the baby’s yolk sac still attached, we knew it was a bit premature. Now, we’re happy to report that the preemie weedy seadragon is the same size as its siblings.


Today, the babies have nearly quadrupled in size to about 7.5 cm (or 3″) and their famous appendages are developing and growing larger. Weedy seadragons grow quickly in their first year, and will be fully grown within two years. They can grow to 45 cm (or 17″) in length.


When the babies first hatched, they ate larval brine shrimp. As the seadragons grew, their appetite became too strong for the larval shrimp, so we fed them live mysis shrimp generously donated to us by Ray Lewis of Aquatic Indicators in Florida. At first, the baby seagradons ate shrimp that were only one or two days old. Now that the seadragons are larger, they dine on 4- or 5-day-old live mysis.


We are keeping the young weedy seadragons in a kreisel, or a special circular tank with circular water flow. The tank’s design makes it easier for the seadragons to capture their free-swimming food and swim with a slight current that simulates their natural habitat. When the seadragons are bigger they’ll be moved to a larger tank with a similar circular flow to give them more room to groove.


Leslee has been blogging about her experience with weedy seadragon breeding for over a year. To catch up, read about the Seadragon Propagation Program and check out Leslee’s trip to Australia to study these spectacular animals in the wild.

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  • Kevin
    November 25, 2013 at 1:12 pm

    Neat. They’re actually a pretty decent size when they’re born, at least as far as fish go, it seems. What’s the plan as they mature? Spreading them to other aquariums as the breeding process is perfected I presume?

    • h6johnson
      November 26, 2013 at 6:57 pm

      Hi Kevin, yes, as these animals mature, the plan is to study them (with Scripps scientists) and then we hope to facilitate more breeding. Eventually, the goal is as you mention, to supply seadragons to other aquariums, like we do with seahorses:

    Scripps Institution of Oceanography UC San Diego