BLOOD OF FRESH-W ATER MUSSELS 
519 
Table 7. — Hydrogen-ion concentration of the blood of fresh-water mussels 
Scientific name 
Common name 
Num- 
ber of 
indi- 
viduals 
7.4 
7.6- 
7.6 
7.7- 
7.8 
7.9- 
8.0 
pH 
8.1- 
8.2 
value 
8.3- 
8.4 
s 
8.5- 
8.6 
Mini- 
mum 
Aver- 
age 
Maxi- 
mum 
Subfamily Uniomnse : 
3 
2 
1 
7.5 
7.7 
Fusconaia undata. _ __ 
Pig toe 
6 
1 
5 
7.6 
7.7 
7.8 
Tritogonia verrucosa _ 
Buckhorn .. 
6 
1 
2 
2 
1 
7.5 
7.8 
8. 1 
Three-ridge 
6 
1 
2 
2 
1 
7.4 
7.6 
7.9 
Pimple back 
1 
1 
7.6 
Monkey face __ 
1 
1 
7. 7 
4 
1 
2 
1 
7. 7 
8. 1 
8.3 
Subfamily Anodontinse: 
Anodonta limneana... 
Southern floater 
3 
1 
2 
7.8 
7.9 
8. 0 
Strophitus rugosus 
Squaw foot. 
1 
1 
8.3 
1 
1 
7.9 
Subfamily Lampsilinse: 
6 
2 
4 
7.8 
7.9 
8.0 
back. 
Proptera alata 
12 
2 
10 
7.7 
7.9 
8.0 
Proptera laevissima __ 
1 
1 

7.7 
Plagiola lineolata 
Butterfly. 
2 

2 
7.9 
7.9 
7.9 
1 
1 
7.7 
Lampsilis anodontoides 
17 
1 
4 
9 
2 
1 
7. 6 
7.9 
8.3 
Lampsilis fal!aciosa_ ______ 
27 
8 
7 
12 
7.7 
8.0 
8.2 
Lampsilis siliquoidea pepinensis... 
Lake Pepin mucket.__ 
26 
3 
6 
12 
3 
1 
1 
7.6 
7.9 
8.5 
Lampsilis ventricosa 
1 
1 
8. 2 
Actinonaias carinata 
River mucket. 
17 
— 
5 
6 
2 
3 
1 
7.7 
8.0 
8.5 
Total 
142 
1 
11 
42 
56 
23 
7 
2 
7.4 
i 7.9 
8.5 
1 Average of all individuals. 
The water from which the animals used in making the determinations listed in 
Table 7 were taken varied in pH value from 7.4 to 7.9, with an occasional value of 
as 
a4 
83 
82 
8.1 
ao 
TL 75 
7.8 
7.7 
7.6 
75 
74 
73 
1.0010 1.0020 19030 1.0040 10050 10060 10070 10000 
SPECIFIC GRAVITY 
Figure 4. — Specific gravity plotted against pH, for normal blood of fresh-water 
mussels, showing trend away from alkalinity toward neutrality with an increase in 
specific gravity. This trend was also evident in blood of the mussels in the series 
exposed to air (v. i.). Average specific gravity (1.0026) and average pH (pH 7.9) are 
indicated by heavy lines 
pH 8. The average pH value of the water in the Mississippi River at Fairport, 
Iowa, just above an apparently healthy bed of mussels was pH 7.65, while that 
of the tank water in which mussels at Columbia, Mo., were kept varied through- 
out the year from pH 7.5 to pH 7.8. When compared with the environment the 
pH of the mussel blood was consistently a little more alkaline than the surround- 
ing water, if the animals were kept well aerated and in average normal condition. 
