Effects of starvation on energy reserves in young juveniles of abalone Haliotis discus hannai Ino

Effects of various degrees of starvation (0-, 5-, 10-, 15-, 20- and 25-day fasted) on tissue protein, lipid, total carbohydrate, glycogen and ash contents, as well as the ratio of soft-tissue to shell weight, were investigated in young juvenile abalone. Haliotis discus hannai Ino (initial shell length: 4.8 +/- 0.6 min, initial live weight: 15.0 +/- 1.3 mg). Results showed that after 25-day starvation, tissue protein, lipid, total carbohydrate, and ratios of soft-tissue to shell weight decreased significantly, whereas the glycogen level remained constant, and ash content increased significantly. During the 25-day starvation, juvenile abalone lost 23.4% of protein, 19.8% of lipid, and 13.3% of total carbohydrate. The corresponding energy depletions were 226.5, 81.3, and 3.0 kJ/100 g dry body weight, respectively. The variation of energy depletion among the energy components is probably evidence of selective utilization of energy reserves by juvenile abalone, and partly a reflection of the predominance of energy components in juvenile tissues.