50 Lake Maxinkuckee, Physical and Biological Survey 



pears at the lake but is soon cured by the examination of a bushel 

 or two of mussels. On September 22, 1907, a man was seen at 

 the south end of the lake with about a peck of shells which he had 

 opened in a vain search for pearls ; on October 8 of the same year 

 a pile of about a half bushel of shells, which had evidently been 

 opened by pearlers, was found in Overmyer's woods. Another 

 pearler was seen in 1907 who had collected a few slugs of almost 

 no value. One of the citizens of Culver, in 1906, submitted a small 

 vial of lake baroques for valuation, but they had no worth what- 

 ever. The greatest enemy of the lake mussels is the muskrat, and 

 its depredations are for the most part confined to mussels near 

 shore. The muskrat does not usually begin its mussel diet until 

 rather late autumn, when much of the succulent vegetation upon 

 which it feeds has been cut down by frost. Some autumns, how- 

 ever, they begin much earlier than others; a scarcity of vegeta- 

 tion or an abundance of old muskrats may have much to do with 

 this. The rodent usually chooses for its feeding grounds some ob- 

 ject projecting out above the water, such as a pier or the top of 

 a fallen tree. Near or under such objects one occasionally finds 

 large piles of shells. The muskrat apparently has no especial pref- 

 erence for one species of mussel above another, but naturally sub- 

 sists most freely on the most abundant species. These shell piles 

 are excellent places to search for the rarer shells of the lake. 



On September 24, 1907, about a bushel of shells, recently 

 cleaned out by muskrats, was found at Long Point where a pier 

 had been removed not long before. The shells were all of rather 

 small size and were in about 18 inches of water. About half were 

 taken and examined. Of these shells 358 were Lampsilis luteola, 

 167 Unio gibbosus, 6 Lampsilis iris, and 1 Lampsilis multiradiata. 

 In the autumn of 1913 freshly opened shells of Lampsilis glans 

 were common along shore at Long Point. The first shells killed 

 are rather small and are probably killed by young muskrats. 



In the winter after the lake is frozen, great cracks through the 

 ice extend out from shore in various directions, and this enables 

 the muskrat to extend his depredations some distance from shore 

 in definite limited directions. During the winter of 1904 a musk- 

 rat was observed feeding on mussels along the broad ice-crack that 

 extended from the end of Long Point northeastward across the 

 lake. The muskrat was about 500 feet from shore. It repeatedly 

 dived from the edge of the ice-crack, and reappeared with a mussel 

 in its mouth. Upon reaching the surface with its catch, it sat 

 down on its haunches at the edge of the creek, and, holding the 

 mussel in its front feet, pried the valves apart with its teeth and 



