Seahorses are fascinating to watch and if you have the chance you should visit the Two Oceans Aquarium in Cape Town where you can see several beautiful Knysna seahorses (Hippocampus capensis) on display. You might even be lucky enough to see a male seahorse giving birth!
The male seahorse gives birth to the young – the female lays her eggs in the male’s pouch and when they are ready, the babies hatch out of the pouch into the water. Watch the video below, kindly produced for us by Homebrew films, of a Knysna seahorse giving birth:
Seahorses have lived in the oceans for about 40 million years.
They have a head shaped like that of a horse, a tail like a monkey’s and male seahorses have a “pouch” like female kangaroos.
Seahorses are fish – they breathe through gills, use their fins to move through the water and hatch from eggs.
The largest seahorse, the big-belly seahorse (Hippocampus abdominalis) measures 35cm from the top of its head to the tip of its tail.
The smallest seahorse, the pygmy seahorse (Hippocampus denise) is only 3cm long!
Seahorses swim upright, propelled by their dorsal fin while the small pectoral fins help to steer them as they glide along.
Seahorses feed on small fishes and shellfishes, which they suck into their mouths.
The eyes of a seahorse are like those of chameleons: one eye looks for food whilst the other watches out for predators.
Seahorses in South Africa
There are 30 to 40 different kinds of seahorses, but only five of these have been seen around the southern African coastline. The Knysna seahorse is the best-known of these and is only seahorse which is endangered.
Knysna seahorses are only found in the Knysna, Keurbooms and Swartvlei estuaries on the south coast of South Africa. They are green to brown in colour and grow to about 12cm in length. They live at depths of 50cm to 8m on sandy bottoms or around clumps of plants.
Urban development is threatening the survival of the Knysna seahorses. Houses and shopping centres are being built right on the water’s edge and polluted water flows directly into the estuaries where seahorses live. Boats and people in the estuaries are also disturbing the unique habitat of these animals.
About 20 million seahorses are caught every year around the world for traditional medicine or for sale as curios. Some people believe that eating dead seahorses will cure asthma, skin problems and even baldness! About a million seahorses are caught every year for display in home and public aquariums.
Fortunately, there is a law in South Africa that protects the Knysna seahorse. This law states that one is not allowed to catch these seahorses or disturb them in their natural environment. There are also strict laws about importing seahorses into South Africa from other parts of the world.
That’s why the Knysna seahorses in our exhibit are not replenished from the wild. Instead, we breed them here from time to time to replenish stock. When we want them to breed, we raise the water temperature slightly. We've introduced quite a number of generations into the exhibit over the years!