Two Oceans Aquarium aquarist Michelle Kirshenbaum is in charge of rearing endangered Knysna seahorses and introducing them to the adults in our exhibit. Seahorses usually hang onto plants or, in the case of the juveniles in the lab, the tank’s airline tube.
We currently have quite a few seahorses in our laboratory. The oldest of the lot, Steve, was born in November 2014 and, along with a few of his cousins, has now joined his uncles and aunts in the Knysna seahorse (Hippocampus capensis) exhibit. The smallest ones were born just a few weeks ago, mid-August.
South Africans will be celebrating Heritage Day on 24 September, so we're making use of this opportunity to celebrate our coastal heritage this month. And what better marine mascot than the beautiful Knysna seahorse? It is endemic to our south coast and is found naturally in only three habitats; the Keurbooms River estuary in Plettenberg Bay, the Knysna Lagoon, and the estuarine portion of the Swartvlei system in Sedgefield.
The Knysna seahorses in our exhibit are not replenished from the wild because there is a law in South Africa that protects this endangered fish. The law states that you’re not allowed to catch these seahorses or disturb them in their natural environment. 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.
Juveniles feed on brine shrimp (artemia), and, says Michelle, “All they do is eat and poop." Typical baby behaviour! "They don’t have stomachs, so they have to eat a lot.”
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! The male seahorse gives birth to offspring – 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. They live at depths of 50cm to 8m, on sandy bottoms or around clumps of plants.