BIGGER - FATTER - OR IS FASTER GROWTH BETTER - CONSIDERATIONS ON CONDITION IN LARVAL AND JUVENILE CORAL-REEF FISH

Analyses of condition data are conspicuous by their paucity in the ext ensive tropical reef-fish literature. Researchers typically quantify a bundance at settlement, with little regard for the demonstrably variab le quality of newly sealed fishes. Condition may be functionally class ified by indices of growth (e.g. the RNA-DNA index or peripheral growt h increments of the otolith), starvation (e.g. height of midgut mucosa l cells), storage (e.g. lipid content), or morphometry (e.g. dry weigh t/length(3)), all of which are variably correlated with each other. At present all indices are species-, stage-, technique-and therefore oft en investigation-specific, as laboratory-reared larvae for calibrating field-collected condition indices are often specific to the rearing p rocedure. RNA indices are particularly appropriate for estimating larv al condition. In pelagic juveniles, or in recently settled juveniles, the width of peripheral growth increments of the otolith estimates ave rage growth rate in length or dry weight during the previous few days, which discerns increasing from decreasing condition. Increment width changes in otoliths are particularly responsive to starvation events, and are correlated with RNA indices. Growth indices have great potenti al for determining which individuals were growing faster, thereby redu cing their pelagic duration, and thus increasing their survival potent ial. The recent debate regarding whether bigger larvae have better sur vival could be re-addressed, by determining if larvae with faster grow th indices have relatively enhanced survival.