July 17, 2012
Creature Feature: Seahorse
BY: Michelle Cassidy
Though you won’t see them saddled and ready to ride anytime soon, seahorses are pretty fascinating little sea creatures.
Named for their resemblance to the horses that we’re used to seeing on land, the seahorse is one of the slowest moving fish in the ocean. They swim upright, unlike their cousin the pipefish, and flutter their dorsal fin up to 30-40 times per second to move around (more like a hummingbird than a horse).
There are 47 distinct species of seahorses, and all are in the genus Hippocampus, which comes from the Ancient Greek for “sea monster.” You can find them in shallow waters throughout the world, especially in seagrass beds, coral reefs, and mangroves, where they can take cover and hide from bigger fish that might want to make a meal out of them.
Seahorses are fairly small, ranging from 0.6 to 14 inches. But the smallest of all are the pygmy seahorses. Scientists are continuing to discover new species of pygmy seahorse, but they’re tough to find because they camouflage themselves and live in or near coral, algae, or seaweed, where they blend so well that they’re nearly impossible to spot. They often use their tails to anchor themselves to a surface, then use their snouts to catch brine shrimp and other small crustaceans floating by.
One of the seahorse’s most unique characteristics is that males carry the fertilized eggs instead of females. The male seahorse has a brood pouch on his front side where the female deposits eggs during mating. He carries the eggs until they’re fully developed, then releases the tiny seahorses out into the ocean to fend for themselves. A single brood can contain up to 1,500 young!
Because seahorses are so elusive, we don’t know very much about their populations worldwide. But the coral reefs, seagrass beds, and other areas they call home are endangered by habitat depletion, pollution, and ocean acidification, which has made some species of seahorse vulnerable to extinction.