5Kornijow R R, Gulati D, Ozimek T. Food preference of freshwater invertebrates: comparing fresh and decomposed angiosperm and fil- amentous alga [ J ]. Freshwater Biology, 1995,33 : 205 -212.
6James M R, Hawes I, Weatherhead M. Effects of settled sediments on grazer-pefiphyton-macrophyte interactions in the littoral zone of a large oligotrophic lake [ J ]. Freshwatter Biology, 2000,44 : 311 - 326.
7Ricciardi A, Rasmussen J B. Extinction rates of North American water fauna[ J ]. Conservation Biology, 1999,13 : 1220-1222.
8Epler J H. Identification manual for the larval Chironomidae ( Dip- tera) of North and South Carolina [ S]. America: EPA Grant#X984170-97,2001.
