366 Papers from the Marine Biological Laboratory at Tortiigas. 



IV. REACTION OF THE GRAY SNAPPER TOWARD ATHERINAS TO 



WHICH HAS BEEN GIVEN WARNING COLORS AND TOWARD 



THOSE OF ABNORMAL FORM, ODOR, OR TASTE. 



ABNORMAL COLOR. 



As the atherinas used in the feeding experiments had usually been colored 

 by an aniline dye and were therefore dead, a test was first made of the re- 

 actions of the snappers toward dead and living atherinas. After a single 

 normal uncolored atherina had been thrown to assemble the snappers, i8 

 other normal atherinas were thrown dead and living alternately. One was 

 talcen as quickly as the other. In no case was there any observable hesita- 

 tion in making the first snap at either dead or living iish. 



T.\BLE I. Rcsutts of feeding gray snappers of the laboratory colony on " zvarningly- 

 colorcd " atherinas in July, 19OS. 



Atherinas were then given various colors by staining them as shown in 

 table I. These were thrown to snappers with the results shown in the table. 

 It appears from the table that the snappers take atherinas colored bright 

 vermilion, deep vermilion, yellow, green, dark blue, light blue, and purple, and 

 all without hesitation and as readily as they take normal or uncolored fish. 



Not only were fish of all colors taken at once, but they were taken as 

 readily when ofifered in succession as when offered alternately with normal 

 fish. The snappers showed no hesitation in taking atherinas of any of the 



