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Gastric Evacuation Rates for Juvenile Largemouth Bass
Author(s) -
Hayward Robert S.,
Bushmann Michael E.
Publication year - 1994
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1994)123<0088:gerfjl>2.3.co;2
Subject(s) - micropterus , bass (fish) , pimephales promelas , trophic level , fishery , biology , juvenile , predation , predator , ecology , minnow , fish <actinopterygii>
In situ estimation of fish daily ration is being used increasingly to test hypotheses related to competition, predation, and anthropogenic effects on fish populations. There is also an increasing demand for robust estimators of fish gastric evacuation rate for use in food consumption models. We selected the largemouth bass Micropterus salmoides for study of gastric evacuation rates (GERs) because (1) it is important in the trophic dynamics of warmwater ecosystems, and (2) a limited data base describing largemouth bass GERs has precluded development of a robust estimator needed for in situ estimates of prey consumption by populations of this species. We estimated GERs for juvenile largemouth bass (82–157 mm total length; 15–70 g wet weight) fed single meals (2% of dry body weight) of live fathead minnows Pimephales promelas at 26°C. A previously unused reciprocal model gave substantially more accurate estimates of largemouth bass GERs than other models. Also, the relationship we observed between largemouth bass body weight and GER was substantially different from the one shown in the literature. Our findings together with results from previous studies of gastric evacuation in largemouth bass suggest that more than one type of evacuation model is needed to accurately estimate largemouth bass GERs for different combinations of temperature, predator size, and meal size.