. A biological survey of the Erie-Niagara system. Supplemental to Eighteenth annual report, 1928. Natural history -- New York (State); Fishes -- Erie, Lake; Fishes -- Niagara River (N. Y. and Ont. ); Erie, Lake; Niagara River (N. Y. and Ont. ). Biological Survey—Erie-Niagara Watershed 231 estimates in pounds per acre of food as he found it in various conditions and sections of the Illinois river. Of the 1,767 animals taken in Chara, per cent (1,086) were crustaceans, mostly the large Caledonia shrimp, Gammarus linmaens, one of the best trout foods known. ''Bloodworms" or midg-e larv
. A biological survey of the Erie-Niagara system. Supplemental to Eighteenth annual report, 1928. Natural history -- New York (State); Fishes -- Erie, Lake; Fishes -- Niagara River (N. Y. and Ont. ); Erie, Lake; Niagara River (N. Y. and Ont. ). Biological Survey—Erie-Niagara Watershed 231 estimates in pounds per acre of food as he found it in various conditions and sections of the Illinois river. Of the 1,767 animals taken in Chara, per cent (1,086) were crustaceans, mostly the large Caledonia shrimp, Gammarus linmaens, one of the best trout foods known. ''Bloodworms" or midg-e larvae, another excellent trout food, formed per cent of the catch and were living in great abundance in the mud be- neath the Chara. These two classes of foods constituted per cent of the total taken and are both highly desirable as food for trout. Other animals taken here were beetle larvae, caddis larvae, mollusks (snails), leeches but these were relatively scarce. In the watercress study, Caledonia shrimps formed per cent (1,675) of the 2,056 animals taken and were dominant in this type of bed as they were in the Chara bed. By comparing the relative productiveness of these two types of beds, Chara is shown to be much the better. A larger number of animals (2,056) was taken in the watercress but their total weight was grams less than the total weight of the (1,767) animals taken in Chara. The reason for such a wide variation in the total weight of each catch seems to be due, partly, to the shrimps. Those taken from Chara were exceedingly large and heavy, 10-15 mm. in length while those taken from the cress were mostly small, 3-7 mm. long and weighed considerably less. Caddis worms also helped to increase the weight of the Chara bed catch as 42 were taken, most of which were large in size, 8-14 mm. long while only one small one was taken in the watercress. The factors con- tributing to this difference in productivity of the plant beds form an important an
Size: 1158px × 2157px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookpublisheralbanyjblyoncompan
