Behavior Patterns 229 



tares for four species have been collected from t\\ o or more in\estigations 

 often widely separated. For example, die preferred temperatures of wall- 

 eyes in Norris Reservoir, Tennessee, are several degrees higher than those 

 for walleyes in Trout Lake, Vilas County, Wisconsin— more than 1000 

 miles farther north. This is probabh^ true also for largemouth and spotted 

 bass although no information is at hand for bass in more northern loca- 

 tions. Fishes shown in table 8.2 are arranged in order of descending 

 (higher to lower) temperature preferences. 



There are a number of records of fish acclimated to low temperatures 

 invading wann water in spite of a lethal effect; ^^' "^^ also, a record of a 

 concentration of fish (mostly white crappies) where the temperature 

 gradient was only 1 to 2°F.^^ 



Rising water temperatures in spring and early summer would eventually 

 force species of fish preferring cool waters out of the upper layers of a 

 lake. For example, the lake trout and walleyes of Trout Lake, Vilas 

 County, Wisconsin, had always left the surface waters by the time 

 spring was well advanced and successful fishermen caught these species 

 after May by trolling with baits at depths of 25 to 100 feet. 



BEHAVIOR PATTERNS 



Fishes have many behavior patterns that are well known, partly be- 

 cause they are common to many species. Other behavior patterns of a 

 more specific nature are familiar to many because the fish are common 

 and widely distributed. Each group of fishes has its own characteristic 

 reproductive pattern, but reproductive behavior will be omitted from 

 this chapter in favor of more general types of activities. Some of these 

 are described below. 



Some Types of Behavior Patterns 



Fishes are so often referred to as "schooling," that one may be led to 

 believe that this is the normal social grouping for these animals. Although 

 not all fishes show schooling tendencies, the subject of social behavior 

 involves all of them and is, therefore, a logical subject with which to 

 begin. 



Social Groupings. Breder ^-^ recognized four degrees of social groupings 

 among fishes: solitary, aggregating, schooling, and podding. Some kinds 

 of fishes show more than one of these grouping classifications in relation 

 to seasonal or sexual behavior. Breder's grouping classifications are de- 

 fined as follows : 



1. Solitary. Fishes that show zero or negative attraction toward others of 

 their kind. 



