98 The Lije Story of the Fish 



care of the brightness factor, each color was finally tested 

 against a whole range of grays, from pure white to absolute 

 black — probably a more conclusive method than trying to 

 measure the brightness values of different colors and equate 

 them. 



One of the first findings was that the untrained black 

 bass, before conditioning had started, had a strong preference 

 for red over all other colors, with yellow in second place. To 

 the bass angler this means that a red lure has the best chance 

 of attracting his prey, with yellow a second choice. As the 

 experiments proceeded, it developed that the fish learned 

 quickly, from five tx) ten trials being enough for them to 

 get the idea; and furthermore that they learned more 

 quickly to avoid the color which brought the electric shock 

 than to approach the one that brought food. In the words of 

 the report, they "learn more quickly to avoid an unpleasant 

 stimulus than to react positively to a pleasant one." In terms 

 of survival value in the wild, this is understandable: one 

 single failure to avoid death (presumably unpleasant) is 

 fatal, whereas failure to approach food (presumably pleas- 

 ant) may be repeated quite often without bringing the end. 



Memory played a part in the experiments. The fish showed 

 almost perfect retention of what they had learned from one 

 day to the next, and some were able to go for a week with- 

 out a lesson and still make the proper response when tested. 

 Vision through the surface film was demonstrated: as soon 

 as the "food color" appeared above the basin, the well tu- 

 tored little fish made a dash for the place where it cus- 

 tomarily entered the water. 



In the end, the experiments proved that the bass could tell 

 red from any other color with the exception of violet, and 

 was almost equally sure on yellow. Greens and blues were 

 the hardest for him to distinguish from each other and 

 from black. Brightness was proved to play no part, for not 



