REACTIONS OF FISHES TO ATMOSPHERIC GASES 



251 



TABLE 16 



Showing the reactions of fishes to a gradient of boiled water accompanied by high 

 carbon dioxide. Data arranged as in preceding tables. Controls in tap water. 

 Gradient between tap and boiled plus carbon dioxide. 



EXPT. 

 NO. 



57 



57 A 

 60 • 

 61 

 62 

 59 

 55 



55 A 

 58 



58 A 

 56 



56 A 



Lepomls 



Lepomis 



Notropis 



Amelurus... 



Umbra 



Catostomua . 



Ambloplltes I 3 



Ambloplites. ...I 3 



Abramis i 3 



Abramls j 3 



Hybopsis 3 



Hybopsls ' 3 



CO2 



IN CC. 



PER 

 LITER 



CROSS- 

 ED CEN-: 

 TER 



PER CENT OF TIME 

 IN HALVES 





50 I 28 



Average . 



29 



TOTAL 

 j TIME 

 INMIN. 



Expt. 



Control 



L.O2 

 High 

 CO2 



6 

 17 



Corre- 

 H.O2 spondlng 

 Low 



CO2 High Low 

 CO2 CO2 



49 i 51 



TURNED BACK FROM 



Expt. 



High 



CO2 



Low 

 CO2 



Control 



Corre- 

 sponding 



High Low 



coughing, gasping and gulping reactions were given with greater 

 frequency and greater intensity than in any of the other experi- 

 ments. 



WTien observed in the glass boxes, Hybopsis, Lepomis Ameiu- 

 rus, Umbra and Ambloplites showed great disturbance in the 

 boiled water with carbon dioxide added. There was uniformly 

 greatlj' increased activity, increased opercular movements, and 

 special reactions, such as gulping, rising to the surface, et cetera, 

 as described for boiled water alone. These were accompanied 

 by some lack of coordination and in one case (Ambloplites) by 

 falling on the side. 



We have in the experiments good evidence that fishes turn 

 back from waters high in carbon dioxide and low in oxygen with 

 precision and vigor. Also that if they enter such localities, they 

 cannot behave normally and may soon die. When we compare 

 these results with those on boiled water or oxygen and with the 

 results on carbon dioxide alone we see that carbon dioxide is the 

 most potent factor yet studied in this series of experiments. 



