Selective feeding of Gammarus pseudolimnaeus upon fresh and senescent leaf tissues of riparian vegetation.

Abstract

Herbivory is the consumption of plants by animals, and an important evolutionary force. Herbivorous relationships have been extensively studied in terrestrial systems, presumably because of the importance of those relationships in agricultural science and food production. In aquatic systems herbivory has not been as carefully examined, and chemical defenses of aquatic plants and plants affecting aquatic systems have been largely ignored. I conducted an experiment to determine if the freshwater amphipod Gammarus pseudolimnaeus selectively feed upon the senescent leaf tissues of plants in its environment. I concluded that Gammarus pseudolimnaeus does signficantly prefer senescent tissues of Alnus rugosa, Caltha palustris, Lemna minor, and Fontinalis hypnoides. The relationship of Gammarus pseudolimnaeus to the plants that it consumes is significant because as a detritivore, it directly affects the lowest trophic levels of the aquatic ecosystems in which it is found, influencing all other trophic levels.