146 



Conservation Department 



Table 2. — The Effects upon Fish Blood of Increasing the Hydrogen Ion 

 Concentration of the Surrounding Water 



Date 



8/10 



8/14 



8/14 



8/29 



8/29 



8/30 



8/30 



9/7 



9/7 



8/10 

 917 



SPECIES 



Erythro- 

 cytes 

 per cm. 



Eryhtro- 



cytea 

 volume 

 per cent 



Erythro- 

 cytes to 

 yield 100 

 per cent 



Bullhead Ameiurut nebulosus) .) . . . . 



Bullhead (Ameiurua nebulosus) 



Pike {Esox lucius) 



Bullhead {Ameiurus nebulosus) 



Goldfish {Carassius auratus) 



Carp (Cyprinus carpio) 



Carp {Cyprinus carpio) 



Carp (Cyrpinus carpio) 



Bullhead {Ameiurus nebulosus) 



700,000 



1.095,000 



1,460,000 



1,420,000 



690,000 



830,000 



710,000 



1,790,000 



1,050,000 



Control Experiments in Water Onlt 



Bullhead (Ameiurus nebulosus) I 2 hrs. . . I 64 ( 1 ,230,000 



Bullhead (Ameiurus nebulosus) Ihr.... 80 1,410,000 



30 



1,100,000 

 1,600.000 

 2,600,000 

 1.800,000 

 1,500,000 

 1.100,000 

 700,000 

 2,700,000 

 1.700,000 



1,900,000 

 1,800,000 



In Tables 4, 5, 6, 7 and 8, we have included data to show^ the j 

 resistance of several species of fish to severe hemorrhage. This i 

 type of work opens up rich possibilites in several directions. In ! 

 the first place it demonstrates the remarkable factors of safety i 

 presented in the blood. In Table 6 we have shown the results from i 

 constantly removing the blood from a carp. In spite of a reduc- 1 

 tion to 7 per cent hemoglobin and a respiratory pigment that occu- ] 

 pied three per cent of the whole blood volume, this animal could ] 

 live and swim normally. This factor of safety explains why fish , 

 can frequently enter very badly polluted areas with impunity. 

 Although the oxygen of these areas may be very deficient, the 

 fish can survive until it escapes. 



In the next place it shows the possibilities of using the fish as ; 

 a test animal for foodstuffs responsible for blood formation in j 

 the body. This is of special importance when we consider the j 

 huge tonnage of liver that is now being consumed daily by those 

 suffering from various anemias. To speed up progress in locating 

 foodstuffs that are as effective as liver it is essential that we have ! 

 good test animals. If we can bleed an animal like a carp, then . 

 feed it a given diet and measure the rate of recovery of its red \ 

 blood corpuscles, we have added one more valuable animal to • 

 those few now used for this important problem. An initial experi- , 

 ment in this direction is shown in Table 7. This specimen of ] 

 Ameiurus nebulosus, the common bullhead, was able to effectively ■ 

 regenerate its blood because we fed it a diet of raw liver. A con- j 

 trol, wliich was run at the same time and not fed, showed no i 

 r''generation. In Table 8 we have shown the effects of constantly 

 bleeding a pike without permitting it to have feed. 



