Biological Survey — Oswego Watershed 89 



type of bottom for they occur where the bottom is muck, gravel, 

 rubble, clay and so forth. However they are limited to cold waters. 

 Fan-tailed darters occur in both cold and warm waters. Yet they, 

 unlike the trout, are restricted to shallow riffles where the bottom 

 is hard, usually rubble. 



In the annotated list, notes are included for nearly all species 

 as to the environment in which the fish has been taken. For the 

 sake of clearness, the designations there used may be explained. 

 Rivers: the Oswego, Seneca, Oneida and Clyde. Large streams: 

 tributaries of approximately 15 feet in width such as Canandaigua 

 outlet. Small streams: tributaries of less than approximately 

 15 feet in width. Lakes: the major lakes of the region ranging 

 in size from Oneida lake to Neatahwanta. Ponds: small bodies 

 of water ranging in size from Duck lake to Mud pond (near 

 McLean). 



Types of bottom are characterized as follows: Bare rock: bed 

 rock. Harclpan: glacial clay. Gravel: small pebbles. Rubble: 

 large pebbles and loose rocks. Sand: fine rock particles. Silt: 

 coarse "soil" particles. Mud: fine "soil" particles. Muck: black 

 swamp deposits formed of decayed plant remains. 



Types of currents are characterized as follows: Torrential; 

 as in the swiftest "white water" riffles. Rapid; as in average 

 riffles, Moderate; as in the deeper pools of a stream. Sluggish; 

 as in deep, comparatively slowly moving waters such as the Oswego 

 river. Stagnant; no appreciable current. 



Fish Association. — -As has been noted in the works of Forbes* 

 and of other certain species of fish are often found associated to- 

 gether. Doubtless the main reason for this is that the environmen- 

 tal requirements are similar for certain groups. When enough data 

 on these requirements are obtained, facts regarding the presence 

 or absence of certain species may be useful as indicating the suit- 

 ability of waters for certain others. In this respect we know that 

 the sculpin (Cottus cognatus, Plate No. 7) may be regarded as an 

 indicator of brook trout water. We have never taken this fish 

 except in cold spring brooks where trout were present or could 

 have been established. 



Although temperature is not the only factor influencing the asso- 

 ciation of fish, it does play an important part and fish may be 

 classed according to their temperature requirements. From the 

 standpoint of fish culture, fish are often separated into warm 

 water and cold water groups. The first of these groups includes 

 fish such as the black basses which will thrive in water of com- 

 paratively high temperature but will not do well in cold waters. 

 The second grouping includes trout and other fish which will not 

 live in warm waters. 



The limits between "warm water" and "cold water" fishes are 

 not fixed. There is a gradual differentiation between the extremes 



* Forbes, S. A. Fresh water fish and their Ecology. 111. State Lab. Nat. 

 Hist., 1914. 



