Young smooth horsefish as seen at Clifton in shallow water.Chrysaora hysoscella
Photos by Belinda Roux
Another young smooth horsefish, seen in much deeper water.
A much larger specimen, showing off its remarkable dorsal fin!
A diver inspecting the docile horsefish at close range
Photos by Guido Zsilavecz
Belinda Roux saw the horsefish shown at a dive at Clifton, in about 5m of water. It was around 20 cm long.
Smooth horsefish are so named because the adults have smooth skins - the juveniles, as shown, are anything but smooth-skinned, and are actually covered by rough little bumps. This fish can grow to 75 cm in length, substantially more than any shown here. They have compressed bodies, that is, they are "narrow", something which is accented even more by their extremely tall dorsal fin over the head.
Most horsefishes are seen in deeper waters - 20m or more, but occasionally and for no apparent reason they are seen in shallower waters - like the one Belinda saw. During one summer SURG members dived several times at Bakoven Rock in Camps Bay, and saw numerous in such shallow water, only for them to dissapear and we have not seen them there since. The image on page 84 of Anton Koornhof's "Dive Sites of South Africa" was taken on one of these dives.
Horsefishes are generally docile fish, and can usually be readily approached. Often they are seen in deep cracks or between plates on wrecks, in which case it is hard to get close, but those out in the open rarely do anything but hang around in the surge. In some cases we have carefully picked them up, in which case they may emit a soft "tok-tok-tok" - quite odd. A classic photo in National Geographic magazine taken in New Zealand shows several related horsefishes half-burried in the sand, with only their heads sticking out. This was not a natural scene, but happened when the photographer wanted to get a "group photo", but could only hold so many in one go - so he, for the fun of it, dug little holes and stuck them in tail-first. To his surprise, most remained quite calm, with only a few shaking themselves free and slowly swimming away. Please do be considerate and do not repeat this experiment; most wild animals do not like being handled, even if they appear docile. Why horsefishes are so docile is not known, and they do not seem to have any obvious defence mechanisms either.
For more details on this and other horsefishes, see "Coastal Fishes of the Cape Peninsula and False Bay", available directly from SURG or from better Cape Town dive shops.
Coastal fishes of the Cape Peninsula and False Bay, a divers' identification guide, G Zsilavecz, 2005.
Smiths' Sea Fishes, MM Smith and PC Heemstra, 1986.
The Dive Sites of South Africa. A Koornhof, 1995.