Chubby clingfish, 3 cm long, with eggs.
Eggs of the rocksucker. White eggs may be un-fertilized ones, or may be lagging in development.
Rocksucker showing how small its eggs are.
Rocksucker, about 25 cm long, with patch of eggs. All photos Guido Zsilavecz
Rocksuckers and chubby clingfish both belong to the same family, the Gobiesocidae. The small chubby clingfish, which reaches a mere 5 cm, can be found under shells on rubble sand bottoms. Turning shells over often reveals an adult with its offspring in small, transparent eggs, the eyes of the young clearly visible.
The rocksucker, a much larger relative reaching 30 cm, is not often seen by divers, although they are widespread on our reefs. Their eggs are seen even less often, as they are usually laid under boulders, rather than on the side of this smooth rock at A-Frame. As can be seen, the eggs are similar to those of the chubby clingfish, being transparent. They are also about the same size. Their size relative to the adults, is of course, massively different: the eggs of the chubby clingfish are about 5% body length, while those of the rocksucker are less than 1%! What the rocksucker eggs lack in relative size is made up for in numbers, and the images clearly show the large patch of eggs, whereas all the eggs of the chubby clingfish can be found under one shell. Of course, the chubby clingfish could lay eggs under several shells, but similarly the rocksucker could lay several patches - not far from this patch was another one, without an adult nearby. It is not certain whether the adults guard the eggs. Rocksuckers often allow divers to approach quite closely, but do eventually move off - this one did not move, and was seen at exactly the same spot over an hour later on a second dive.
For more details on rocksuckers and their relatives, see "Coastal Fishes of the Cape Peninsula and False Bay", available from better diveshops in Cape Town or directly from SURG.
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.
Two Oceans, a guide to the marine life of Southern Africa, GM Branch, CL Griffiths, ML Branch and LE Beckley, 1994.