Photo Guido Zsilavecz
Photo Helene Clarke
This small fish was seen at Long Beach, hiding between featherstars on the sand. The bright blue colour gave it away. Its usual range is south to Aliwal shoal, although it has been found in Algoa Bay as well. This species has been seen a few times before, at Sunny Cove and other locations. This is a juvenile, and on growing becomes paler, with a mostly yellow body, retaining only small spots of blue.
Cowfishes belong to a group usually called the "boxfishes", because they are boxy and hard - only the fins, mouth and eyes can move. Some are square in profile, others, like this one, more triangular. Their hard bodies, and the spines, serve as defense, as they can swim only slowly. It is thus possible to catch one and pick it up carefully, as shown in the second photo.
As with many visitors to the Cape, it is unlikely to survive for very long in our cold waters.
For a photo of a yellow individual, see "Coastal Fishes of the Cape Peninsula and False Bay", now available from SURG and better dive shops in Cape Town.
Coastal fishes of the Cape Peninsula and False Bay, a divers' identification guide, G Zsilavecz, 2005.
Coastal Fishes of Southern Africa. PC Heemstra & E Heemstra, 2004
Smiths' Sea Fishes, MM Smith and PC Heemstra, 1986.
More reef fishes and nudibranchs, D King & V Fraser, 2001.