Compensatory Growth Following Starvation Or Undernutrition In Chinese Shrimp, Fenneropenaeus Chinensis(Osbeck)

A detailed literature review of ecophysiological effects of starvation on crustaceans and studies on the compensatory growth of aquatic animals was undertaken; A series of feeding experiments were conducted to investigated growth compensation following starvation or undernutrition in Chinese shrimp, Fenneropenaeus chinensis (Osbeck). The results are summarized as follows: 1. The effects of previous periods of starvation on the subsequent changes in body mass, food consumption, food utilization and body composition in Chinese shrimp, F. chinensis (initial wet weight: 2.164 ±0.055 g, mean ±SE) were investigated. During feeding period the shrimp were fed on polychaete worm, Neanthes japonica. Upon refeeding, shrimp responded to various periods (4, 8 and 12 days) of food deprivation by exhibiting hyperphagia. There were the characteristic patterns that the intensity of compensatory appetite increased in proportion to the length of the starvation periods and that the hyperphagic responses of the starved shrimp were not sustained and within 8 days declined to levels not significantly different from those of the controls fed continuously at satiation feeding. During subsequent refeeding, the previously 4 day starved shrimp were only slightly, and the 8 and 12 day starved shrimp were significantly higher in specific growth rates in terms of dry matter, protein and energy content (SGRd, SGRp, and SGRe) than those of the controls. However, there were no significant differences in SGRw (SGR in terms of wet weight) among all the experimental groups. During the course of refeeding, there were no significant differences in food conversion efficiencies (FCEw, FCEd, FCEp and FCEe) among all groups, and only the shrimp previously starved for 8 days showed slightly higher FCEs (FCEd, FCEp and FCEe) than the controls. There was a trend that, within the first 8 days of refeeding, FCEw decreased with the length of starvation periods, which may be attributable to changes in body water content. With food deprivation, lipid, protein and energy content decreased and water content increased. At the end of starvation, the shrimp starved for more than 8 days showed significantly lower lipid, protein and energy content and higher water content than the controls. After 32 days of refeeding, no significant differences in water, protein and energy content were found between the starvation-satiation shrimp and the controls, except that lipid content of the shrimp starved for 4 or 12 days was still lower than that of the controls. The results of this study suggest that the shrimp regulate their appetite and growth rate in relation to their previous nutritional history. 2. The recovery growth experiment in the Chinese shrimp (1.454 ±0.150 g), following different periods of starvation, was conducted. The experiment lasted for 32 days for each tested group. Group C, S4, S8 and S12 were deprived food for 0 (control), 4, 8 and 12 days, respectively. Then each group was refed at ad libitum ration level for its rest experimental time. At the end of starvation mean body weight (dry weight and wet weight) of each starved group (S4, S8 and S12) was significantly lower than that of group C; At the end of experiment the mean body weight of group S4 was similar to that of group C, while the respective body weight of group S8 and group S12 was still significantly lower than that of group C; Upon realimentation after periods of starvation, the feeding rate in terms of wet weight in each previously starved group were significantly higher than those in group C. The results indicated that there was completely-or partially-compensatory effect in the recovery growth in the Chinese shrimp followingstarvation, and that the compensatory effect mainly resulted from significant increase of the feeding level in the recovery growth. 3. A 40-day feeding experiment was conducted to investigate the effect of previous food restriction on the compensatory growth response in Chinese shrimp, F. chinensis. Four groups of shrimp with initial body weight of 2.189 ±0.093 g were...