Differential Seasonal Migration of the Crayfish, Orconectes Virilis (Hagen) in Marl Lakes

Abstract

In an earlier study during 1962 and 1963, movement of female Orconectes virilis from shallow to deeper water in summer was noted in West Lost Lake, Otsego County, Michigan. The present additional observations on O. virilis, during three summers and in three lakes, confirm this migration. Evidence from other areas suggest that this movement is a general phenomenon of the species throughout most of its range. Migration of females appears to be associated essentially with muturation of the gonads.