Diet of the South African abalone Haliotis midae

Abstract

The crop and stomach contents of Haliotis midae were determined at two study sites (on the south-western and western Cape coasts) in both summer and winter. A total of 18 species of algae was recorded in the diet, the most important being kelp Ecklonia maxima (56 per cent by volume) and Plocamium spp. (21 per cent). There was little size-related variation in diet over a range of shell width of 65–145 mm, except that Ulva spp. was of significantly greater importance in smaller specimens. The proportion of kelp consumed was higher on the West Coast than on the South Coast (66 vs 46 per cent), but Plocamium spp. was more important on the South Coast (39 vs 3 per cent of diet). I n summer more than 80 per cent of the samples contained these two species, but the winter diet was more varied at both sites. A comparison of diet and availability of food items indicated that some are selected for and others avoided.