Studies on southern Australian abalone (genusHaliotis) X. Food and feeding of juveniles

Abstract

Abstract The natural diet of juvenile Haliotis laevigata Donovan and Haliotis scalaris Leach was examined at West I., South Australia. Crustose coralline algae are the principal food eaten by both species from a length of 5 to 10 mm. From 10–20 mm length the diet switches to dead seagrass blades and drift algae such as Lobospira bicuspidata and Asparagopsis armata; geniculate coralline algae also become more important with increasing length. Large brown algae such as Ecklonia radiata, Sargassum spp. and Cystophora spp. which dominate the habitat are avoided. Crustose corallines are rasped from the rocky substratum whereas the drift algae lie between and under boulders where they are captured by the abalone. From about three years of age, both abalone species occur in higher densities in deeper water where they are presumed to migrate to feed on the preferred food - algae, which are abundant there as drift.