Lake Maxinkuckee, Physical and Biological Survey 49 



veloped. This is possibly related to opportunities of fertilization 

 of ova, and is most frequently observed in L. ventricosa and L. 

 luteola; no such precociously developed mussels were found in the 

 lakes. 



A large and well developed female Lampsilis ventricosa was 

 transplanted from Yellow River into Lake Maxinkuckee. On 

 being examined two years later in the autumn when this species 

 is usually gravid, it was found to be sterile. 



The natural infection of fishes of the lake with the glochidia of 

 the mussels does not appear to be common. The gills of an im- 

 mense number of fishes were examined for parasites, but no 

 glochidia were noted. Some young bluegill and redeye, exposed 

 to glochidia of L. luteola in the autumn of 1912, took very readily. 



Very young mussels were either few, or very difficult to find. 

 Diligent search was made for them, especially in the sandy bottom 

 near Long Point, the sand being scooped up and sieved through 

 fine-meshed sieves. Numerous and varied forms of life were thus 

 obtained, such as Sphaerium, Pisidium, caddis-cases, etc., and 

 rather small but by no means minute examples of L. luteola. 

 These young shells were remarkably brightly rayed. Half-grown 

 Q. rubiginosa were fairly common in the beds of Lost Lake. 



Proportion of various species in the lake: Of a collection of 

 340 living mussels collected October 17, 1907, at Long Point, 252 

 were Lampsilis luteola, 41 L. ventricosa, 21 Unio gibbosus, 18 

 Anodonta grandis footiana, 5 Strophitus edentulus and 3 Lamp- 

 silis subrostrata. In deep water U. gibbosus and Anodonta would 

 have given a higher percentage, and in the Lost Lake beds Quad- 

 rula rubiginosa would be present in considerable relative abund- 

 ance. 



Parasites, enemies, and diseases: As a general rule the mus- 

 sels of lakes, ponds and bayous are more heavily infested with 

 parasites than those of swiftly flowing rivers, the probable rea- 

 son being that in still waters the parasites can migrate more 

 easily from one mussel to another than where there is a swift cur- 

 rent. The mussels of the lake are not nearly so badly parasitized 

 as those of the sloughs of the Mississippi, the dead water in the 

 Maumee above the dams, or those of Twin Lakes a few miles to the 

 north. The parasites will be taken up more fully in consideration 

 of the various species of mussels. Cotylaspis insignis and several 

 species of Atax are the most common parasites. Unlike the mus- 

 sels of most of our rivers, the mussels of the lakes are compara- 

 tively exempt from the ravages of man. A few are killed and 

 used for bait, and now and then a mild case of pearl fever ap- 



4 17618 Vol. 2 



