EARLY LIFE-HISTORY PATTERNS OF ATLANTIC NORTH-AMERICAN FLATFISH - LIKELY (AND UNLIKELY) FACTORS CONTROLLING RECRUITMENT

Life history information for 4 families (51 species) of Atlantic North American flatfish showed that 14 species could be grouped into two categories according to life history pattern. Four high-latitude species had large eggs, long development times, and low growth parameter K. Life history traits of the other 10, lower-latitude, species displayed reverse tendencies and had relatively invariate life history traits. Where age-specific estimates of interannual recruitment variation (CVR) existed, all species showed a decline with age, but there was wide variation, suggesting controls on recruitment may operate at different stages, depending upon species type. Using latitudinal and inshore-offshore gradients in food, predation and abiotic factors, we develop hypotheses for likely controls on different species types according to their range or position within their range. With decreasing latitude, food increases in importance predation probably follows a reverse trend. Abiotic variability is highest in temperate regions and inshore. Species and locations are suggested which would provide the most rigorous tests of hypotheses of recruitment controls.