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Revised food consumption estimate of a bluegill sunfish population in Wyland Lake, Indiana, U.S.A.
Author(s) -
Gerking Shelby D.
Publication year - 1972
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1972.tb05678.x
Subject(s) - biology , lepomis macrochirus , zoology , body weight , growing season , population , food consumption , ecology , fish <actinopterygii> , fishery , demography , sociology , agricultural economics , economics , endocrinology
The estimate of food consumption by the bluegill sunfish ( Lepomis macrochirus ) population of Wyland Lake, Indiana, was examined with reference to recent research on the length of the growing season and the effect of body weight, ration and activity on growth efficiency. Growth efficiency was measured in the laboratory in terms of protein, comparing nitrogen assimilated with nitrogen accumulated over a period of about 30 days. The revised consumption of protein was 134.9kg (or 1407kg live weight of aquatic organisms, 444 kg/ha) during a growing season of 111 days compared with the original estimate of 127.3 kg calculated for an assumed growing season of 150 days, a difference of only 6%. The correspondence between the two estimates was coincidental. The original estimate was made at a time when the growing season had not been measured and the effect of ration and body size on growth efficiency was not precisely known. Corrections for these factors plus that for activity compensated for one another, closely approaching, by chance, the original value.