Size and species selection of zooplankton by larval and juvenile walleye (Stizostedion vitreum vitreum) in Oneida Lake, New York

摘要: Young-of-the-year walleye (Stizostedion vitreum vitreum) ranging from 7 to 38 mm in total length were collected Oneida Lake, New York, 14 May 11 June, 1989. Stomach contents analyzed document feeding strategies employed during their early life stages. A distinct change both type and size of prey was evident as the progressed through first 4 weeks life. The diet 10- 13-mm consisted 77.3% (by number) cyclopoid copepods; 13–19 mm consumed calanoid copepods (96.1%), while older juveniles, 29–38 mm length, mostly cladocerans (Daphnia spp.) (88.3%). smallest class fish zooplankton 0.50–1.50 mm long, second 1.25- 2.00-mm zooplankton, third 1.5- zooplankton. Electivity calculations field laboratory studies revealed that these changes a result active selection by young walleye. ...