Horned blenny Parablennius cornutus from Star Walls, Hout Bay.
Photo by Andrew Taylor
Two more horned blennies
Both photos by Guido Zsilavecz
This uncommon blenny is one of the few species of blennies found in Cape Town waters. It is usually very skittish, and will hide quickly unless approached quite carefully. Inshore it is most often found sheltered in caves and cracks, with only the occasional individual out and about. Further offshore it seems to be bolder, and may be found on reef walls and wrecks.
This species reaches 15 cm in length, although I am sure we've seen ones which are larger than that. Colouration is quite variable, but most have 6 irregular darker bars along the flank. The common name refers to the cirri above the eyes - these are like little branched trees, and are often a bright orange or red.
This fish is similar in appearance to many klipfishes, the pleated toadfish and the Cape triplefin, but can be distinguished by the steep profile of the head and by being more compressed (i.e. flattened side-to-side) than comparative fishes - for example, the pleated toadfish also has the wrinkly skin this blenny has, but has a much broader mouth and flatter head.
For further details on this and other blennies, klipfishes, triplefins and toadfishes, see "Coastal Fishes of the Cape Peninsula and False Bay", available directly from SURG or better Cape Town dive stores.
Coastal Fishes of the Cape Peninsula and False Bay - A divers' identification guide. G Zsilavecz, 2005