526 
BULLETIN OF THE BUREAU OF FISHERIES 
values were below the average normal. After 96 hours, although still below the 
average normal specific gravity for mussel blood, the specific gravity of the blood of 
these individuals in distilled water tended to rise, judging from the few observations 
beyond 96 hours. This rise in specific gravity is suggestive in connection with the 
pH values of the blood. 
H0UR5 
Figure 9. — Specific gravity of the blood of fresh-water mussels in distilled water 
Table 12 . — Changes in specific gravity and pH of the blood of fresh-water mussels in distilled water 
Scientific name 
Common name 
Hours of 
exposure 
Condition of animal 
pH 
Specific 
gravity 
Washboard _. 
4 
Heart beating 
7.7 
1 0091 
_ ___do _ . _ 
4 
do 
7.7 
1 0093 
Do 
do 
4 
7.7 
1 0094 
do _ _ ___ __ 
4 
7.7 
1 0030 
Do 
do 
24 
Moribund 
8. 1 
1 0090 
Do 
do _ _ _ _ ___ 
24 
8.3 
1 0091 
Do 
do ___ ___ 
24 
Moribund __ 
7.9 
1 0095 
Do 
do ... __ ___ ___ . 
32 
7.6 
1 0094 
Do _ 
do ______ _ ___ 
32 
Heart beating. _ 
7.7 
1.0025 
Do 
do 
32 
Moribund 
7.6 
1 0096 
Do 
do_ 
32 
Heart beating __ 
7.7 
1 0027 
Do 
___do _____ 
32 
7.7 
1 0097 
Do 
do 
32 
do. 
7.5 
1 0098 
Do 
do. _ _ ___ _ 
32 
Heart beating 
7.7 
1 0099 
Do 
32 
do 
7.7 
1. 0035 
River mucket.. . 
40 
do___ 
8. 1 
1 0017 
Do 
do _ 
40 
8.0 
1 0019 
Do - 
__ ..do 
40 
8.0 
1 0020 
Washboard 
48 
7.6 
1 0015 
do_ ___ _ __ _ 
48 
do ___ _ 
7.3 
1.0016 
Do 
do 
48 
7.6 
1 0017 
Do 
do 
48 
Heart beating __ 
8.0 
1.0018 
Do 
do 
48 
do 
7.4 
1.0021 
Do 
_ ___do _ 
48 
7.9 
1 . 0022 
Do 
do _ _ 
48 
do 
7.9 
1. 0023 
Do 
. ___do _ _ ._ __ 
48 
Moribund _ 
7.3 
1. 0024 
Do 
do 
52 
Heart beating _ 
7.7 
1. 0023 
Do 
___do 
52 
7.9 
1 . 0023 
Do 
do 
52 
do __ 
7.9 
1. 0024 
Do _ 
do __ _ __ 
76 
do 
8.1 
1. 0025 
Do 
do . 
76 
Moribund 
8.2 
1. 0029 
River mueket 
92 
7.6 
1 0012 
Do 
do 
92 
do _ ___ 
7.7 
1.0012 
Do 
.do 
92 
do _ 
7.6 
1.0013 
Washboard 
96 
7.5 
1. 0016 
do 
96 
7.5 
1 0026 
Do 
do 
96 
do 
7.5 
1. 0027 
Pope’s purple. 
96 
do 
7.5 
1. 0026 
Do * 
.do.I 
96 
7.5 
1. 0027 
Paper shell 
96 
7.5 
1. 0016 
Washboard 
116 
Moribund __ 
7.8 
1.0013 
do -__ 
116 
Heart beating. 
8. 1 
1.0014 
Pope’s purple 
144 
7.5 
1. 0027 
Do t 
do 
144 
do 
7.5 
1.0029 
Paper shell 
144 
7.7 
1 0018 
Southern floater 
172 
Dead. ... 
7. 1 
1.0020 
Pope’s purple 
172 
8.4 
1. 0028 
Do.! 
* do_l___l 
172 
do 
8.3 
1. 0029 
S3? 
Note. — “M oribund, ” under condition of animal, designates a mussel in which the heart was not beating when shell was opened 
but an animal still responding to tactile stimulation of the foot or mantle. 
