Endangered
Cape seahorse
Hippocampus capensis
Cape seahorse is a ray-finned fish in the family Syngnathidae (order Syngnathiformes) — Hippocampus capensis, recorded as Endangered.
Appearance
Colouration is strongly influenced by the surrounding environment and a particular individual's mood. It varies from pale green to brown (often with darker speckles) to purplish black. The body is encased in a series of bony rings, the snout is relatively short, and the neck arches in a smooth curve without a crown.
The Knysna seahorse is a small, delicate creature with a standard length of up to 12 centimetres.
Range and habitat
The Knysna seahorse occurs mostly in areas with high vegetation cover (at least 75%), and is associated with five dominant aquatic plants: Zostera capensis, Caulerpa filiformis, Codium extricatum, Halophila ovalis and Ruppia cirrhosa. While the Keurbooms and Swartvlei estuaries both have very dense plant cover, vegetated sites only make up approximately 11% of the Knysna Lagoon. Large areas of habitat in this system may thus be unsuitable for H. Capensis.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
In crisis
The limited range of this seahorse puts it at great risk of extinction. Genetic data from the mitochondrial control region indicate that, even though each of the three populations of Cape seahorse has a unique combination of haplotypes, there is no support for the hypothesis that each represents a distinct subspecies. There is thus no compelling reason not to translocate individuals between estuaries, should this become necessary.
Low genetic diversity in the Swartvlei estuary suggests that this population is partially isolated from the other two populations. Census data from 2002 and 2003 (WWF-SA) indicated that the population sizes of Cape seahorse in the Keurbooms and Swartvlei estuaries can at times far exceed that in the much larger Knysna Lagoon.
CITES lists this taxon on Appendix II. Confirm the current appendix on the CITES checklist.
Cape seahorse is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Cape seahorse, Wikidata item Q2673571. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
