Metabolic depression and whole-body response to enforced starvation by <i>Crassostrea gigas</i> postlarvae

Citation:
Garcia-Esquivel, Z, Bricelj VM, Felbeck H.  2002.  Metabolic depression and whole-body response to enforced starvation by Crassostrea gigas postlarvae. Comparative Biochemistry and Physiology a-Molecular and Integrative Physiology. 133:63-77.

Date Published:

Sep

Keywords:

aerobic enzymes, biochemical-changes, Crassostrea gigas, cytochrome oxidase, development, electron-transport-system, energetics, energy reserves, enzyme-activities, excretion, juvenile, metabolic depression, mytilus-edulis, nutritional-status, oyster, pacific oyster, protein-synthesis, starvation, virginica gmelin

Abstract:

Physiological and biochemical measurements were performed on six oyster (Crassostrea gigas) cohorts, in order to: (a) investigate the whole-body response (growth, energy content, metabolic and excretion rates) of 2-week-old postlarvae (spat) to enforced (0-8 days) starvation, and (b) test the potential use of three aerobic enzyme systems as indices of physiological condition. Starvation resulted in exponential reduction of postlarval metabolic and excretion rates, as well as a linear decrease in enzyme activity. These response mechanisms effectively limited the loss of endogenous reserves after 2 days of starvation and maintained the oyster's functional integrity over prolonged (8 days) starvation. Proteins appeared to be selectively conserved during short-term (2 days) starvation, as suggested by a decrease in total protein content, while maintaining constant weight-specific enzyme activity. Postlarvae starved for 2 days exhibited relatively higher lipid losses, lower mortality and lower metabolism than metamorphosing stages, thus suggesting a greater buffering capacity to starvation in the former. The activity of the electron transport system may be a useful indicator of long-term stress or developmental condition of oyster postlarvae, while citrate synthase and cytochrome oxidase could be used as indicators of growth rate. None of these enzyme systems is recommended as an index of aerobic metabolism during short-term starvation. (C) 2002 Elsevier Science Inc. All rights reserved.

Notes:

n/a

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DOI:

10.1016/s1095-6433(02)00112-5