Nutritional requirements of abalone Haliotis (Gastropoda) - I. Development of semipurified test diets for abalone.

Abstract

Feeding experiments were conducted three times to develop a semipurified test diet for abalone which is essential for investigation on nutritional requirements. Juvenile abalone Haliotis discus hannai INO weighing 3.1-4.3g in live weight (29-34mm in shell length) were fed on one of the variety of the formulated test diets containing casein or white fishmeal as a protein source, and different levels of sodium alginate, lipid and a mineral mixture, for 30 and 40 days, respectively.The growth rate and feed conversion efficiency (FCE) were compared with those obtained by feeding with live fronds of the alga Eisenia bicyclis as a control, which was known to have high dietary value for this herbivore. Dietary value of the casein diet was found to be comparable or superior to that of the alga. While feeding abalone on a white fishmeal diets resulted in a lower growth and FCE, being about 60% of those compared to the casein diets. These results clearly indicated that the casein diet used in these experiments was suitable as a semipurified test diet for abalone. Based upon the results of growth rate and FCE, it was concluded that an optimum level of sodium alginate, lipid and the mineral mixture in a casein diet was 20-30%, 5% and 4%, respectively.