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

INTRODUCTION

The burrowing amphipod Pontoporeia affinis LindstrJm (1855), the
most abundant macrobenthic organism in Lake Michigan, was originally
described from lakes in northern Germany. Subsequently, Smith (1874)
described P. hoyi and P. filicornis from the Great Lakes. Ekman (1913)
described P. weltneri from Lake Vittern, Sweden. Juday and Birge (1927)
sent specimens of P. hoyi from Green Lake, Wisconsin, to G. 0. Sars
who concluded that this species was synonymous with.P. affinis. Adamstone
(1928) decided that P. filicornis was also identical with P. affinis.
SegerstrRle (1937, 1950) in a revision of the genus, showed that males of
P. affinis and P. welterni were identical and that P. kendalii, described
by Norton (1909) from Lake Champlain, Vt., was also synonymous with
P. affinis. Bousfield (1958) indicated that a large, ecologically distinct
form of this amphipod found in the Ungava Bay region of Quebec may
prove to be distinct from the LindstrUm form. However, Bousfield
concluded that the Ungava Bay amphipod should be designated Pontoporeia
affinis until more information on the taxonomy, distributional ecology,
and physiology of this organism becomes available.
SegerstrRle (1937) concluded that P. filicornis is identical with
the penultimate instar of P. affinis and suggested that it may be a neotenic
form of P. affinis. He designated P. filicornis as P. affinis var.
brevicornis. It is interesting to note that while P. affinis var. typica

1