. Bulletin. Geography. 126 COMMUNITIES OF SMALL LAKES belong to dififerent families, but have similar cases and similar habits. This is a good example of what is meant by mores. The forms are very different, but their mores are similar. The Johnny darter, the straw- colored minnow (Fig. 72), and the blunt-nosed minnow are usually found (105) in the shallowest water. The Johnny darter, the blunt- nosed minnow, the miller's thumb, and probably other minnows breed in these situations (105, 106). Crayfish are common here (in Wolf Lake, Cambarus virilis). Snails (such as Pleurocera subidare [Fig. 7
. Bulletin. Geography. 126 COMMUNITIES OF SMALL LAKES belong to dififerent families, but have similar cases and similar habits. This is a good example of what is meant by mores. The forms are very different, but their mores are similar. The Johnny darter, the straw- colored minnow (Fig. 72), and the blunt-nosed minnow are usually found (105) in the shallowest water. The Johnny darter, the blunt- nosed minnow, the miller's thumb, and probably other minnows breed in these situations (105, 106). Crayfish are common here (in Wolf Lake, Cambarus virilis). Snails (such as Pleurocera subidare [Fig. 73], and sometimes Goniobasis livescens) are common on the shoals, crawling over the bottom which is always covered with diatoms, desmids, etc. These algae serve as food for the mussels. Miss Nichols found 16 species of algae on the shell of a specimen of Pleurocera taken from a Wolf Lake shoal. In the deeper waters (3 ft.) we find the same crayfishes and the same snails fewer in number than in the shallower parts of the shoals. Associated with them are the mussels (especially Lampsilis luteola, Anodonta mar- ginala and grandis). Such sandy and gravelly bottomed shoals in 1-3 ft. of water are especially important to the food fishes. There are many first-class food fishes in all such lakes. Of those in Wolf Lake seven breed in these shallows. There are the large-mouthed black bass (Fig. 74), the bluegill, the pumpkinseed, the green sunfish, the perch (Fig. 75), the speckled catfish, and the crappie. Nearly all in making their nests scrape the bottom clear of all debris; the males guard the nests. The number of food fishes in a lake is related to the area of such shoals, which are accordingly of great economic importance and should be protected from destruction by the encroachment of vegetation and accumulation of debris. Associated with the fish are occasional musk turtles {Aro- mochelys odorata). Shoals are invaded by bulrushes and bare bottom may exist between them. Here the vi
Size: 1105px × 2261px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectgeography, bookyear19
