Abstract: Eight hundred Labidocera euchaeta specimens with food in their alimentary canal were collected from the Bohai Sea, and the analysis of their alimentary canal contents shows that Labidocera euchaeta is microplanktonivorous, and feeds mainly on micro copepods, occupying 76.4% in its food composition, in which, Paracalanus parvus is the main prey (74.7%), and others occupy a less portion on diatom (23.0%), dinoflagellates(1.1%), chrysophytes(<0.1%) and ciliates (1.5%). The food composition of this species has an obvious seasonal variation.The mean replacement rate of food group in four seasons is 30.7%, and that of food species reaches to 40.3%, showing that the diatom in its food is increased gradually from spring to winter, and on the contrary, the copepods is decreased, its feeding intensity is increased in the order of spring>autumn>summer>winter.

Key words: Bohai sea, Labidocera euchaeta, Feeding, Magnolia grandiflora, resuspension, air pollution, Platanus acerifolia, ICP