282 Index 



Tilapia, 



competition between T. mossamhica 

 and T. sparrmani, 43 

 Toxaphene for lake renovation, 148 



dosages of, 149 



first use of, 148 



residual properties, 149 



selective toxicity of, 149 



toxicity as compared to rotenone, 149 



toxicity to aquatic invertebrates, 149 

 Trephosia, 142 

 Trout, 



below coldwater reservoir outlets, 34 



early production of in U. S., 3 



hatchery selection of, 102 



importation into S. Africa, 81 



in catch-out ponds, 257, 258 



maximum summer temperature for, 45 



standing crop in pounds per acre, 64 

 Trout, brook, 



lethal temperature of, 46 



preferred temperature of, 228 

 Trout, brown, 



restricted movement of, 235 

 Trout, lake, 



preferred temperature of, 228 

 Trout, rainbow, 



"black" trout, 216 



food competition with red-side shiners, 

 118 



pigmentation of, blind, 216 



restricted movement of, 235 

 Trout lakes, 



selective poisoning of, 143 

 Turbidity, 



colloidal clay in, 46 



effects of, 46 



effects on fishes, 47 



electrically charged clay particles, 47 



in Oklahoma ponds, 46 



Underfishing, 187 



definition of, 187 

 U. S. Engineers, recreational values by, 



252-253 

 U.S. F. and W. S, 



Office of River Basin Studies, 11 

 U. S. Soil Conservation Service, 



origin of, 16 



pond sponsoring activities of, 8 

 Useful sizes, 



of fish, 70, 71 



Vegetation, aquatic, 



competition for space, 169 

 control with sodium arsenite, 177 



functions of, in lakes, 169 



movement into new waters, 168 



role in management, 176 



types of, 169 

 Vegetation control, 



herbicides for, 174-175 

 Ventura Marsh (Iowa), 125 

 Verheijen, F. J., 221 

 Viosca, Percy, Jr., 84, 110, 189 

 Vision, 213 



field of, 216 

 Vision, color, 



in largemouth bass, 213 



in bluegills, 213 



in elritze, 213 



importance of, in fishing, 213 



preferences for colors, 214 



stimulus of red, 213 

 Vision, underwater, 214-216 



Walleye, 



dead eggs in Lake Gogebic, 103 



intraspecific competition of, 123 



killed by supersaturation of Oo, 55 



length of life of, 202 



limited range of, 233 



minimum useful size of, 71 



mortality rate of, 207 



preferred temperature of, 228 



shortage of prey for, 124-125 



spawning temperature of, 98 



standing crop in pounds per acre, 64 

 Walls, G.L., 214-216 

 Warmouth, 



competition with other species, 121-123 



growth affected by dragline, 89 



mortality rate of, 207 



number of eggs per fish, 93 

 Water levels, 



manipulation of, in lakes, 1 1 

 Water treatment, 



in drained lake basin, 141 

 Water-supply reservoirs, 20 



bottom-rooting fish in, 21 



eutrophic lakes, 21 



oligotrophic lakes, 21 



recreational uses of, 21 



use of rotenone in, 21 

 Weiss, G. F., 190 

 Westman, J. R., Smith, R. K., and Har- 



rocks, A., 244 

 Whitmore, C. M., Warren, E., and Don- 



doraff, P., 232 

 Whitcwood Creek (S. D.), 



pollution of, 47 

 Wiebe, A. H., 



fertilizers in water, 5 



