Ecology of the burrowing amphipod, Pontoporeia affinis, in Lake Michigan / by Wayne Paul Alley.

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has been recorded from both European and North American lakes, P.
affinis var. brevicornis is found only in North America, which suggests
that the latter form developed in this continent since the Pleistocene.
Segerstrile (personal communication) has found brevicornis in all the
St. Lawrence Great Lakes with the exception of Lake Ontario and feels
that it will also be found there with additional sampling.
Segerstrile (1959) presents an excellent account of the distribution
of P. affinis in Eurasia, while Henson (1954) gives an extensive review
of the North American distribution. Pontoporeia affinis is found in the
brackish waters of arctic Russia, Siberia, and Alaska, and within the
Baltic and Caspian Seas. It inhabits the oligotrophic lakes of the once
glaciated sections of northern Europe and is also widely distributed in
Siberian lakes and the estuaries and rivers of arctic Eurasia. In North
America it has been reported in the larger oligotrophic lakes of Canada,
Ungava Bay, St. Lawrence estuary, the-Great Lakes, Green Lake of
Wisconsin, the Finger Lakes of New York, and Lake Washington on the
west coast.
Various workers have provided estimates of the numerical importance of this amphipod in Lake Michigan. Eggleton (1936, 1937) reported
as many as 8,400 individuals/m2 at one station and showed that this
amphipod comprised 64 percent of the total number of macrobenthic
invertebrates. An examination of his data indicates an average of approximately 700 amphipods/m2O Merna (1960) found the average standing
imately 700 amphipods /m o Merna (I 960) found the average standing