Role of Predacious Rotifers in Great Lakes Plankton Dynamics

摘要

The objectives of this research were to develop techniques for the laboratory culture of common limnetic rotifers and to determine feeding rates for the predaceous Great Lakes species Asplanchna and Ploesoma on their preferred food items. Food preferences of Asplanchna and Ploesoma were first determined through direct observation of feeding in natural prey assemblages. Initial efforts were directed toward establishing laboratory cultures of the species through a knowledge of the diet and feeding behavior. Phytoplankton species from the upper Great Lakes and Douglas Lake, Michigan were then isolated and cultured during seasons when populations of desired rotifer species were present. These phytoplankton isolates were tested for their food value on a variety of rotifer species.