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When spot Leiostomus xanthurus larvae began to feed (age 3 d at 24øC, 4 d at 22øC, 5 d at 20øC, 5-6 d at 18øC), little endogenous energy was available to them. If food was withheld 3 d or more, most larvae died even if food then became available. Larvae were equally vulnerable to starvation throughout the prefiexion stage (-<3.8 ram standard length, the stage occurring before the upward flexion of the notochord tip). Later-stage larvae (flexion and postflexion, during and after notochord flexion, respectively) survived food deprivation significantly longer than prefiexion-stage larvae. Discriminant analysis of six body measurements (standard length, head length, eye diameter, body depth at anus, body depth at cleithral symphysis, body depth at pectoral fin base) identified significant changes in larva body shape during starvation and successfully classified larvae according to nutritional condition. Moderately starved and starved (food withheld for 1-2 and 3-4 days, respectively) prefiexion larvae were morphologically similar, indicating that the effects of starvation proceeded rapidly. Fed and moderately starved (food withheld for 1-4 days) fiexion-postfiexion larvae were morphologically similar, indicating that starvation of older larvae proceeded more slowly. The proportion of prefiexion larvae correctly classified improved when starved and moderately starved fish were combined into a single category (83% correctly classified); classification of fiexion-postfiexion larvae improved when fed and moderately starved fish were combined (87% correct).

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Life history traits of Atlantic menhaden Brevoortia tyrannus and gulf menhaden B. patronus were compared and interpreted within the context of a bet-hedging model that predicts what traits should evolve in local environments when the survival of the larval stage is less predictable than that of the adult stage. Atlantic menhaden appear to spawn in a relatively lesspredictable environment. Compared with gulf menhaden, Atlantic menhaden are older at the onset of sexual maturity and have a longer reproductive span, as well as a longer spawning period. Atlantic menhaden produce larger eggs, and their larvae are larger at hatching and younger and larger at first feeding; the larvae appear to grow faster but they are relatively smaller than gulf menhaden at their first metamorphosis. Heavy exploitation of Atlantic menhaden has resulted in a truncation of the age structure, contraction of their spawning range, a reduction in lifetime fecundity, and possibly modifications of the egg size distribution. Thus, the risk of reproductive failure may have increased because spawning now takes place over narrower geographic and temporal ranges.