SIZE-DEPENDENT EFFECTS OF CONTINUOUS AND INTERMITTENT FEEDING ON STARVATION TIME AND MASS-LOSS IN STARVING YELLOW PERCH LARVAE AND JUVENILES

Starvation rates of fish larvae living in patchy prey environments can have an important impact on cohort survival and recruitment. Despite this, little is known about how fluctuations in feeding experience inf luence starvation resistance and how this changes with ontogeny. Fish previously exposed to fluctuating food densities may not respond to lo ng periods without food in the same way as fish previously exposed to a constant prey density. In a series of laboratory experiments with la rvae and juveniles of yellow perch Perca flavescens, we tested the eff ects of continuous and intermittent feeding on times to starvation and on mass loss up to death from starvation for fish with initial total lengths of 10, 15, and 20 mm. Results indicated that proportional mass loss up to starvation was independent of fish mass, but that it did d epend on feeding history. Fish that fed continuously before starvation all died after losing the same proportion of body mass (55%), but int ermittent feeders died when they were slightly heavier (51-46% of body mass lost). Times to 50% mortality followed a different pattern; ther e was no significant difference in times to 50% mortality for fish tha t had fed continuously or intermittently for the same number of days b efore starvation. We conclude that short-term fluctuations (less than or equal to 4 d) in food availability do not appear to affect times to starvation but do influence mass loss during starvation in young yell ow perch.