An electrophoretic survey of allozyme variation was conducted in four, high
ly polymorphic loci on nine populations of ostracod Candona neglecta Sars f
rom three different environments: the profundal of post-glacial lakes, deep
muddy bottom of the Baltic Sea and small astatic water bodies. The results
suggest lack of genetic isolation between populations from lake profundal
and the Baltic Sea. On the other hand a very distinct founder effect can be
noted in the case of young, isolated populations from small astatic basins
. It is suggested that a population inhabiting a large lake may be genetica
lly subdivided due to differentiated eutrophication.