Hatching Date Influence on Age-Specific Diet and Growth of Age-0 Largemouth Bass

Largemouth bass can hatch over a 70-d period, and among fish less than 90 d old, those hatched earlier can grow faster than those hatched later. Because faster growth of age-0 largemouth bass has been positively linked with fish consumption, it has been suggested that faster growth of largemouth bass hatched earlier was also due to higher fish consumption. We determined hatching-date-specific diets and growth of largemouth bass up to about 180 d old, collected in summer and fall 1987 in a North Carolina reservoir. Frequency of fish consumption for age-0 largemouth bass of all sizes tended to decrease as the growing season progressed. Largemouth bass that hatched earlier, however, were piscivorous at a younger age and maintained a higher level of piscivory late in the growing season than did fish that hatched later. Dietary differences that were hatching-date-dependent seemed to be due to seasonal decrease in prey fish availability. The growth advantage for fish hatched earlier was primarily expressed for fish less than about 85 d old. No growth differences related to hatching date were observed among fish older than 85 d. Studies are needed to determine whether the faster growth of fish hatched earlier results in lower mortality and ultimately in greater recruitment.