Abstract
Sample of stomach contents collected on 10 dates from May to October, 1978, were used to describe the diet and estimate the daily ration of subadult largemouth bass (primarily age-III fish) in Lake Rebecca, Minnesota. The method of Elliott & Persson (1978) was used to estimate daily ration. Data from sources in the literature were used to quantify gastric evacuation, which was found to be adequately described by an exponential decay model. The exponent of gastric evacuation increased exponentially with temperature. Seasonal changes in the diet with respect to composition, distribution of food among stomachs, and food particle size were reflected in the seasonal pattern of growth. Weight gain and the formation of scale annuli did not occur until the diet shifted from large bluegills and insects to age-0 largemouth bass and bluegills. Estimates of daily ration ranged from almost zero in mid-May and early June to over 5% in late August. The use of median weights of stomach contents was found to yield more meaningful estimates of the daily ration of individual bass than those based on means. Estimates based on medians were consistent with the observed pattern of growth and with information on maintenance rations and satiation levels. A growth-limiting lack of suitably-sized forage fish apparently occurred in the early part of the growing season.
Original language | English (US) |
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Pages (from-to) | 265-275 |
Number of pages | 11 |
Journal | Environmental Biology of Fishes |
Volume | 7 |
Issue number | 3 |
DOIs | |
State | Published - Jun 1 1982 |
Keywords
- Bluegill
- Feeding model
- Food consumption
- Food particle size
- Forage base
- Growth