The Product'wity of Fish Food in Oneida Lake 8i 



2. Algae and the Lower Plants 



Lower South Bay is noteworthy for the great development 

 oi the lower plants known generally as algcC. These lowly 

 plants are of primary importance because they form the food 

 of a large percentage of animals upon which fish feed and 

 even supply fish directly with food. Dr. MacClement remarks 

 ('15, p. 202) that: "The cjuantity of unicellular plants per 

 unit volume of water decides the quantity of the Protozoa, 

 Rotifera and Crustacea which may inhabit the waters. These 

 latter are known to serve as the chief if not the only food of 

 the young and small fish. Favorable conditions of shelter and 

 food are indispensable to the growth and rapid development of 

 the young food fish. We are therefore quite safe in deciding 

 that a prime biological condition for a plentiful fish fauna is 

 the presence of an abundant growth of microscopic plants." 



" The surroundings most favorable for the growth of the 

 more minute alga; are quiet waters, sunlight, and a plentiful 

 growth of larger plants such as Chara, Potaniogeton, Elodea, 

 Utricularia, and Myriophyllum as bottom and shore growths. 

 These larger plants serve as shelters and homes for the minute 

 forms, and wherever the former are absent, we cannot expect 

 the latter to be abundant." ^MacClement states that Chara is 

 the most important substratum for minute algae. 



Piatt ('15) has made a very interesting study of the 

 " blanket algae " of shallow, permanent and temporary pools 

 at Ithaca, New York. The filamentous algae included 16 

 species of Spirogyra, and representatives of the genera Mou- 

 geotia, Zygnema, Vaucheria, OsciUatoria, Ulothrix, Micros- 

 pora, and ^Inahccna. These associated genera varied in 

 seasonal abvmdance, and at certain times some genera were 

 absent. Diatoms and desmids were abundant. These algae 

 floated in thin layers, or formed thick masses. 



The animal population was found to be large and varied. 

 The Protozoa and Rotifera were well represented. Of oli- 

 gochsete worms, three genera were observed. Planarian and 

 other turbellarian worms were present. Of the mollusks. 

 Lymncca, Physa, and Planorbis occurred. The statement that 

 these snails are ' not regular inhabitants of the surface algae. 



