Comparing Ceratophyllidia

July 23, 1998
From: Bill Rudman

PHOTO: Kwajalein Atoll, Marshall Ids., 15m, June 1983. Photo: Scott Johnson (from Brunckhorst, 1993: Plate 9F).

I have added this picture of Ceratophyllidia for comparison with Phyllidiopsis cardinalis. This remarkable phyllidiid has large spherical dorsal tubercles, scattered over its otherwise smooth dorsum. Brunckhorst, 1993 considers that the only named species, C. africana, is restricted to the western Indian Ocean and suggests Western Pacific species can be separated into two further species. His main distinguishing features (Brunckhorst, 1993) are the presence or absence of dark markings on the dorsum and whether the spherical tubercles are a uniform dark colour (grey or brownish - in Pacific species), or with black spots (in C. africana). I have seen specimens of both colour forms from New Caledonia so it is possible that Ceratophyllidia africana is a widely distributed species with a variable colour pattern. The spherical tubercles on the back of Ceratophyllidia are attached by a short narrow "stalk". When disturbed the animal is able to break off the tubercles so often animals can be found with a mixture of large and small (growing) tubercles which are replacing ones which have been broken off. Specimens in collections often have only a few or no tubercles.
Bill Rudman.

Copyright © Australian Museum, 1998-2010