Food utilization by Haliotic asinina Linnaeus

Experiments on food utilization by the Thai abalone, Haliotis asinina, were conducted over a period of 6 mo with nine species of macroalgae-Acanthopho ra spicifera, Gracilaria fisheri, Gracilaria salicornia, Gracilaria tenuist ipitata, Enteromorpha intestinalis, Caulerpa racemosa, Dictyota dichotoma, Padina minor, and Sargassum polycystum. The highest growth rate (70.3 +/- 3 .4 mu m/day in shell length 23.6 +/- 2.4 mg/day in weight), highest surviva l rate (95.6 +/- 1.6%), and the best food conversion rate (3.3 +/- 0.5) wer e obtained with the red alga, G. tenuistipitata. The brown alga, P. minor, gave the lowest growth (2.1 +/- 3.0 mu m/day in shell length; -0.3 +/- 0.3 mg/day in weight) and survival (7.8 +/- 1.6%) rates. The proximate composit ion of these nine species of algae was determined to suggest correlation wi th growth rates. G. tenuistipitata was found to have the highest content of protein and carbohydrate.