We’re gearing up for Father’s Day, which made me think about the many different kinds of “wild” dads there are here at the Aquarium. While they’re all deserving of our appreciation, none go above and beyond quite like seahorses and weedy seadragons. When these species reproduce, it’s the male who nurtures the developing embryos and carries them to term. In short, pregnant dads! Really makes you rethink gender roles, doesn’t it?
This unique reproductive method is exclusive to the family Syngnathidae, which also includes pipefish and pipehorses. Some other things all syngnathids have in common are fused jaws, the absence of pelvic fins and thick, bony armor covering their bodies — but male pregnancy, in terms of pure “wow” factor, is their main calling card as a group of species. The female deposits the unfertilized eggs with the male, who then cares for the growing embryos until they’re born. However, no two syngnathids share the exact same reproductive process. This includes our seahorses and seadragons, who differ in a couple of interesting ways.
First of all, the seadragon and the seahorse carry fertilized eggs in different locations. A pregnant seahorse looks pretty familiar to us humans, as they carry their young (who often number in the thousands, by the way) in a pouch located in their abdominal area. This gives them a sort of potbelly appearance. Seadragons, on the other hand, carry their eggs on a specialized patch of skin at the base of their tails.
The hatching processes of the two species are also completely different. Seahorses’ brood pouches begin to expand right before they give birth. This happens as the fully-grown seahorse embryos begin to hatch from their egg membranes and move freely around the pouch. Once the pouch is at capacity, the seahorse finally gives birth, releasing the entire brood at once in dramatic fashion.
Meanwhile, seadragons give birth to their brood more slowly over a period of several days. The baby seadragons hatch one by one rather than all at the same time, decreasing the competition for food by dispersing the brood over a larger area of ocean. You could say seadragon dads go the extra mile to set their kids up for survival in the wild, however, it doesn’t look as impressive in captivity.
If you want to see these amazing aquatic parents up close, come visit us at the Greater Cleveland Aquarium in the First Energy Powerhouse on the West Bank of the Flats. Bring your own dry-land dad on Father’s Day, June 17th, and he’ll get in free with the price of a general admission ticket — find out more here.