Baby seahorses, or seahorse fry (no, not seafoals), look pretty much the same as their parents – only smaller and cuter. Like their parents, they are also very bad swimmers. And their tiny size and lack of swimming skills contribute to their dismal survival statistics: only five fry out of every 1,000 are thought to make it to adulthood. Still, there’s good news, as well – more on which later.
To understand where cute baby seahorses like this pink specimen come from, we have to go back to their moms and dads. It all starts with a bit of courtship, with the male and female meeting up in the early morning hours to ‘dance’ together, swimming with tails intertwined. Sometimes they may even change color. And this behavior can go on for a few days.
Eventually, the ‘getting to know you’ period ends, and the seahorses are ready to get down to business. The male starts off the process by pumping water through his kangaroo-like pouch, displaying its emptiness to the female and letting her know that he’s ready for her eggs. Snout to snout, the two of them then spiral upwards through the water, performing their special mating ritual dance.
As they cling to each other (much like this baby is clinging to its bit of seaweed), the female seahorse uses her ovipositor (egg-laying tube) to place anywhere between 50 and 2,000 eggs (depending on the species) into the male’s waiting pouch. The male jiggles around a bit to get the eggs into position in his brood cavity. Now, he fertilizes the eggs, which then stick to the spongy lining of his pouch. Having done her bit, the female seahorse proceeds to swim away, and the hard work is left to the male.
When all is ready, the male’s pouch is sealed, protecting his precious cargo. During gestation, he produces a hormone called prolactin to feed the eggs and regulates the salinity of the water in the pouch to get the soon-to-be seahorses ready for life in the salty sea.
When the seahorse fry are ready to be born, somewhere between 10 to 25 days after the eggs are laid, the male seahorse’s muscles begin to contract to push them out of the pouch. He holds onto something, like a strand of seagrass, and starts to twist himself around to expel the fry until his pouch is empty. This process can take hours!
Unfortunately, any fry left in the pouch are bad news for dad, as it is thought they die and rot – meaning male seahorse can suffer infections and die. Another theory behind this condition is that during the mating ritual, tiny bubbles containing bacterial infections can enter the pouch.
Unlike some fish species, seahorses don’t eat their young – but that’s about as far as their parental concerns go. Once the fry, like this pair, are out of the pouch, they’re on their own in the big blue world. The first thing they do is try and find something to cling to, to avoid being swept off by ocean currents. Then, once they’ve found their anchor, they feed on microscopic organisms in the water.
Look at this cutie. It’s a shame that baby seahorses like this one face so many obstacles in their first few days. Apart from being swept away from feeding grounds or into water too hot or too cold for them to survive in, they might also end up as a meal for predators. As bad as their chances are, however, the odds are increased by their having spent their time as eggs protected in their father’s pouch.
Sadly, natural threats are not the only problem for baby seahorses. Pollution and loss of habitat through human activity have also reduced our chances of finding youngsters like these in the wild. Fishing practices further reduce the number of adults around to give birth to young. Because of all this, over 35 species of seahorses are now considered threatened.
To combat this drop in seahorse numbers, aquariums around the world are experimenting with captive breeding. Up to now, this has been quite challenging, because the tiny seahorse young require special food to survive. Fortunately, there have been some great recent successes in seahorse husbandry (that’s the good news we promised earlier). Ideally, of course, we’ll find a way to clean up the oceans so that baby seahorses can continue to be born and live their lives in the wild.