SUMMARY 



The activity of 12 little tunny in a large pond was observed 

 during September 1952 under control conditions (no stimulation), when 

 a pair of lures was dipped into the water once every 2 seconds, and 

 when the lures were used together with stock extract of tuna flesh. 



Observations were made in an "attraction area" which 

 could be viewed from the top of a 20-foot tower. Activity was re- 

 corded verbally on a tape recorder, and later transcribed to a kymo- 

 graph drum„ The kymograms furnished quantitative data on activityo 



As compared with control conditions, schools entered 

 the area more frequently when stimulated with the lures, and still 

 more frequently when stimulated with lures plus extract. 



As compared with control conditions, the fish spent more 

 time in the area when stimulated with lures, and still more time when 

 stimulated with lures plus extract. However, the difference in rela- 

 tive time between the two experimental conditions was not statisti- 

 cally significants 



When activity was expressed as number of fish-seconds 

 per unit time in the area, the results were similar to the foregoing. 

 When lures and extract were used together, there was a dulling of 

 the response with repeated testing. 



The use of both lures and extract increased the rate of 

 swimming from an average of 2, 12 feet per second for controls to 

 an average of 3,84 feet per second. 



The fish made many more passes at the lures when 

 stimulated with extract^ showing a heightened feeding response. 



Although, in general, the fish nnade more passes at 

 white as compared with colored lures, the superiority of the white 

 lures was slight. It may have been associated with greater visibility 

 rather than color preference. There is no assurance that white 

 lures would be superior to colored lures in the open sea. 



76 



