All fish / Syngnathidae

Knysna seahorse

Hippocampus capensis

Also known as cape seahorse, knysna sea horse, capensis seahorse, ケープタツノオトシゴ, 克尼斯纳海马, 南非海马

This is a small, rough-skinned seahorse that is usually mottled brown, olive or almost black and has a short snout and a low crown. It lives only in a handful of estuaries in South Africa, holding on to eelgrass and other plants, and is kept mainly by public aquariums for conservation breeding and education.

Care at a glance

Care level

Hard

Temperament

Peaceful

Adult size

10 cm

Temperature

16 to 24 °C

pH

7.8 to 8.4

Smallest tank

120 litres

Keep as

Pairs or small groups kept on their own

Diet

Carnivore: live and frozen mysis, enriched Artemia and small amphipods, offered several times a day

Swims

Middle of the tank

Lifespan

2 to 4 years

Water

Brackish

Wild range

South Africa: Knysna, Swartvlei and Keurbooms estuaries (Western Cape)

Breeding

Pairs tend to be monogamous, and the male carries the eggs in a brood pouch before releasing well-formed young. Public aquariums have bred it successfully, but raising the fry needs a steady supply of live food such as rotifers and newly hatched Artemia.

Good to know

It is listed as Endangered by the IUCN, and all seahorses are on CITES Appendix II, so wild-caught fish are protected and trade is strictly controlled. It does best in cool, brackish to marine water with slow flow and should not be kept with fast or aggressive feeders.