EFFECT OF CRUDE OIL POLLUTION ON OYSTERS 
167 
increase in the salt content of the water was found on these beds during previous field 
investigations, it is probable that the oysters in this region were exposed to much lower 
concentrations of brine than those used in the experiments. This is also indicated 
by the fact that the Barre brine, in concentrations of 50 parts per thousand, was 
found to be toxic to the boring sponge, whereas a prolific growth of this organism 
was found on a high percentage of the oysters in the vicinity of the oil wells. 
EFFECT OF BRINE ON GLYCOGEN CONTENT OF OYSTERS 
During the period from February 7 to March 8, 1934, studies were made of the 
changes in glycogen content of oysters kept in sea water to which brine water from 
the Barre wells had been added in varying amounts. Two hundred and ten oysters 
were used, of which a representative sample of 10 oysters was taken to determine 
their glycogen content at the beginning of the experiment. For this experiment a 
4-compartment wooden tank was arranged as follows: Compartment 1, 50 oysters as 
control in 135 liters of sea water; compartment 2, 50 oysters in a mixture of 130 
liters of sea water plus 5 liters of brine; compartment 3, 50 oysters in a mixture of 125 
liters of sea water plus 10 liters of brine; and compartment 4, 50 oysters in a mixture 
of 120 liters of sea water plus 15 liters of brine. The water in all compartments was 
changed once each week and continuously aerated during the course of the experiment. 
The salinity of the water in the different compartments was as follows: Compartment 
1 (control), salinity 31; compartment 2, salinity 34.5; compartment 3, salinity 38.7; 
and compartment 4, salinity 42.8. 
At the end of each week 10 oysters were taken from each compartment and 
analyzed for glycogen content by P. S. Galtsoff. The results obtained are given in 
the following table: 
Table 7. — Effect of different concentrations of Barre brine on glycogen content of oysters 
[Experiment G 2] 
Date 
Percent glycogen, fresh basis 
Feb. 7 
Feb. 14 
Feb. 23 
Mar. 1 
Mar. 8 
Average 
Control 
2. 16 
3. 33 
2. 74 
1.93 
4. 36 
2. 90 
Brine, 5 liters ... 
(2. 16) 
(2. 16) 
(2. 16) 
2. 66 
4. 77 
2. 92 
3. 24 
3. 15 
Brine, 10 liters 
3. 06 
3. 38 
5. 26 
2. 92 
3. 35 
1.71 
3. 15 
2. 65 
2. 25 
2. 38 
THE EFFECT OF OIL ON FEEDING OF OYSTERS 
By Paul S. Galtsoff and R. O. Smith 
EFFECT UPON THE ADDUCTOR MUSCLE 
It has been established that oysters have a well-developed chemical sense and 
are sensitive to a wide variety of chemical substances (Hopkins, 1932). When an 
irritating chemical solution is brought in contact with the tentacles, situated along 
the free border of the mantle at the edge of the shell, they retract sharply. The 
reaction may spread to the mantle, which contracts, and to the adductor muscle, 
the response of which to stimulation according to Hopkins (1932) “bears a relation- 
ship to concentration similar to that of the tentacular reaction, but the reaction time 
is longer.” 
