Anger, K.
In meroplanktonic larvae, growth is normally accompanied by developmental changes in major physiological, biochemical, morphological, behavioural, and ecological traits, and these patterns can be further modulated by natural variations in the physico-chemical environment. This paper reviews patterns of growth and chemical composition in planktotrophic marine decapod crustacean larvae developing under constant close-to optimum conditions, as well as alterations imposed on these patterns by nutritional, thermal, or osmotic stress. Available data suggest that different suboptimum conditions (food limitation, unsuitable temperatures or salinities) may exert similar bioenergetic effects which, in general, can be measured as a decline in rates of development and growth, or in the proportions of certain chemical constituents of larval biomass. Among the latter, the fractions of carbon (C), total lipids, triglycerids, polyunsaturated fatty acids, RNA, and the ratios between carbon:nitrogen (C:N), lipid:protein, and RNA:DNA appear to be sensitive chemical indicators of stress. The quantitative relationships between elemental (C, N) and proximate biochemical (lipid, protein) composition may vary with the nutritional condition, developmental mode (planktotrophy vs. lecithotrophy), clade, and possibly, also between larvae obtained from the natural plankton vs. those reared under artificial conditions in the laboratory ("domestication effects"). Besides further comparative laboratory investigations, more field data will be necessary to increase the realism of our models of larval growth and development in the Decapoda and other crustaceans.
(Biologische Anstalt Helgoland, Meeresstation, D-27498 Helgoland, Germany)
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