TJic Prod lie tiz'i/y of Fish food in Oneida Lake 107 



Planorbis pan'us, Ilyalella, aiul . Isellits arc the cliaraclcristic 

 animals of tlie nnul bottcjni in shallow water (see lij^ure 35). 



2. Mnd Bottom, 6-12 Feet Deep. Areas equivalent to 528 

 units (of 16 square inches*) were examined and 1,096 mol- 

 lusks and 1,039 associated animals were collected, the average 

 per unit area being 2.07 mollusks and 1.96 associated animals 

 (Table No. 22, A). The large number of Amnieola, repre- 

 senting nearly 52 per cent of the total molluscan life, of which 

 /Unnicola bakeriana forms 34.9 per cent, is noteworthy. The 

 12 species of Pisidiiun total 15.2 per cent. Five species of 

 clams were collected, of which EUiptio coniplanatiis alone rep- 

 resented 73.4 per cent. Of the associated animals, dipterous 

 larv?e compose 28 per cent and the ostracods 49.4 per cent. 

 The latter, however, are small and their bulk is much less than 

 that of the dipterous larvae and other associated animals. The 

 small number of Isopoda, 01igoch?eta, Amphipoda and Clado- 

 cera is noteworthy. Among the mollusks Amnieola emarginata 

 and Wdvata sineera may be noted as being confined to water 

 10 .or more feet deep. Lampsilis radiata oneidensis first ap- 

 pears at a depth of 9 feet (see figures 36-38). 



3. Mud Bottom, 12-18 Feet Deep. Two dredgings (96 small 

 unit areas) were made in water deeper than 12 feet, in Lower 

 South Bay. Mollusks afforded 181 individuals and associated 

 animals 47; the averages for these are 1.88 mollusks and .48 

 associated animals, or 2.37 animals per unit area. Again 

 Amnieola is the characteristic mollusk the two forms collected 

 rei)resenting 18.7 per cent. Amnieola bakeriana niniia alone 

 being 16.5 per cent. The five species of Pisidium total but 4 

 per cent. Three species of mussels were collected, of which 

 EUiptio coniplanatiis forms 89.4 per cent. The associated ani- 



* The method of using the large dredge has been described on 

 page 23. The area studied is approximately 768 square inches or the 

 equivalent of 48 units (16 square inches). The 11 dredgings with 

 the hu'ge dredge, therefore, total 528 of these smaller imits. The num- 

 ber of animals is recalculated, by dividing the numl)er of individuals 

 of the dredge unit by 48, to facilitate comparison of the valuation with 

 the smaller units of the other habitats. It should be borne in mind that 

 there is not the accuracy in the deep water calculations that was possible 

 in the shallow water. 



