reported efficient lipid digestibilities of H. rubra and H.
laevigata at dietary level of up to 3.4% only. Further, higher lipid levels
may bring negative effects on the digestibility of other nutrients such
as amino acids, fatty acids, etc. and therefore may affect growth rate of
the animal. The study of Van Barneveld et al. (1998), has shown that
dietary lipid content of more than 5% in the form of either fish oil,
vegetable oil or a combination of both, had a negative influence on
amino acid digestibility. Thongrod et al. (2003), have also shown in
their study with H. asinina that high levels of dietary lipid as well as dietary energy give negative effects on abalone growth while high
levels of carbohydrates support growth.