The Size of Certain Naiades from Western Lake Erie in Relation to Shoal Exposure

The variability of shell characters in fresh-water mussels, particularly those of size, shape and color, has received attention from a considerable number of malacologists. Since many taxonomists in the group have relied entirely upon these characters for specific and varietal designations, investigations into their significance are of importance. During July and August of 1937, three ecologically distinct habitats were studied in the island area of western Lake Erie, in an attempt to correlate, if possible, the limnological factors operating in these habitats, with the size of certain mussels living there. More than 1000 specimens were collected. These were represented by 24 species, eight of which were present in large enough numbers to be of value in our measurements.