TEMPERATURE AND SHELL MOVEMENTS OF OYSTERS 
9 
Table 2. — Effect of temperature on percentage of time oysters remain open 1 
Series 1 (3 days) 
Series 2 (15 days) 
Series 3 (4 days) 
Series 4 (29 days) 
Series 5 (14 days) 
Time 
Average 
temper- 
ature 
Average 
per cent 
time 
open 
Average 
temper- 
ature 
Average 
per cent 
time 
open 
Average 
temper- 
ature 
Average 
per cent 
time 
open 
Average 
temper- 
ature 
Average 
per cent 
time 
open 
Average 
temper- 
ature 
Average 
per cent 
time 
open 
•C. 
5.03 
°C. 
7. 19 
°C. 
8. 15 
° C. 
8. 72 
° C. 
10.37 
5.10 
71.7 
7. 26 
71.0 
8. 16 
100.0 
8.75 
68.5 
10. 36 
64.3 
ty p p-j 
4.93 
50.0 
7.09 
71.6 
8. 08 
100.0 
8. 55 
69. 5 
10. 13 
62.5 
4.67 
48.3 
6.90 
66.0 
7.94 
100.0 
8. 34 
62. 5 
9.88 
55.7 
4.50 
33.3 
6.74 
62.8 
92.0 
8. 12 
64.5 
9.60 
58.0 
5am 
4. 17 
20.0 
6. 55 
57.2 
7.78 
100.0 
7.96 
57.0 
9. 51 
54.0 
4.07 
8.3 
6.47 
52.6 
7.76 
96.0 
7.89 
57.0 
9.42 
63.0 
7 a. m - 
S.80 
11.6 
6.1,0 
46.0 
7.79 
95.0 
7.80 
56. S 
9. 31 
67.8 
3.80 
13.3 
6.47 
34.5 
7.84 
94.0 
53.8 
9. 39 
71.0 
9am 
3.90 
1.7 
6. 61 
37.3 
7 98 
84.0 
8.03 
50.5 
9. 55 
65.3 
10 a tti 
4.73 
13.3 
6.94 
40.6 
8.06 
77.0 
8. 35 
53.6 
9.86 
66.0 
11 a m 
5.50 
25.0 
7. 39 
48.5 
8.38 
85.0 
8.80 
58.8 
10.32 
70.2 
12 a m 
6.23 
88.3 
7.83 
63.0 
8.64 
90.0 
9.24 
73.2 
10.75 
1 d m 
6.40 
100.0 
8. 14 
80.5 
8.82 
100.0 
9.54 
84.3 
11.05 
90.0 
2 p td 
6. 67 
100.0 
8.37 
85.8 
8.85 
90.0 
9. 75 
91.7 
11.24 
94.5 
3 D ~m 
6.50 
100.0 
8.48 
88.5 
8.65 
97.5 
9.90 
91.0 
11.43 
93.0 
4pm 
6. 37 
95.0 
8.36 
%. 2 
8.50 
100.0 
9.90 
95.0 
11.65 
94.5 
p m 
6. 07 
8. 18 
96.2 
8. 27 
100.0 
9.78 
95.5 
11.50 
94.5 
0 p m 
5.60 
96. 7 
7.99 
96.0 
8. 17 
100.0 
9.57 
93.3 
11.28 
89.3 
7pm 
6.43 
7.79 
93.5 
8. 22 
100.0 
9. 38 
88.0 
11.08 
81.8 
8pm 
5.37 
96! 7 
7.70 
95.0 
8. 12 
100.0 
9.30 
85.5 
11.02 
74.2 
9pm 
5.33 
100.0 
7.64 
94.6 
8. 12 
100.0 
9.24 
84.3 
10.98 
73.0 
10 p m 
5.20 
95.0 
7.43 
86.5 
8. 17 
97.5 
9.03 
80.7 
10.74 
75.5 
n p m 
5.13 
80.0 
7. 29 
85.3 
8.17 
90.0 
8 88 
80.8 
10.59 
75.0 
12 p. m — 
5.03 
73.3 
7. 19 
76.8 
8. 15 
100.0 
8.72 
73.6 
10.37 
68.5 
Average 
5.18 
62.84 
7.38 
71.87 
8. 18 
94.50 
8.86 
73.73 
10. 46 
74.34 
Maximum 
6.67 
100.0 
8.48 
9.90 
91.0 
11. 55 
94.5 
Minimum — 
3.80 
11.6 
88.4 
61.6 
6.40 
2.08 
46! 0 
42.5 
40.9 
7. 80 
56.3 
9.31 
67.8 
Difference 
Difference in per cent time open 
calculated for temperature dif- 
2. 87 
2. 10 
34. 7 
33.0 
23.8 
Series 6 (12 days) Series 7 (12 days) Series 8 (18 days) Series 9 (18 days) 
Time 
Average 
temper- 
ature 
Average 
per cent 
time 
open 
Average 
temper- 
ature 
Average 
per cent 
time 
open 
Average 
temper- 
ature 
Average 
per cent 
time 
open 
Average 
temper- 
ature 
Average 
per cent 
time 
open 
Average 
temper- 
ature 
Average 
per cent 
time 
open 
0 C. 
0 C. 
0 C. 
0 C. 
0 C. 
12 p. m 
12.44 
13.46 
14.75 
14.76 
16.50 
1 a. m 
12.47 
92.8 
12.52 
97.7 
14.80 
96.7 
14.78 
98.6 
16. 17 
95.0 
2 a. m 
12.28 
92.5 
12.40 
99.5 
14. 47 
92.4 
14. 47 
97.8 
16.00 
99.2 
3 a. m 
12.08 
93.3 
12. 25 
100.0 
14.38 
93.6 
14.36 
96.4 
15. 85 
100.0 
4 a. m 
11.76 
93.3 
12. 19 
94.5 
14. 17 
93.6 
14. 17 
91.9 
15.83 
96.6 
5 a. m_. - 
11.43 
95.8 
11.96 
95.5 
14. 01 
92.3 
13.94 
95.0 
15.45 
91.6 
6 a. m 
11.15 
100.0 
11.90 
98.2 
13.86 
91.8 
13.86 
96.1 
15.35 
100.0 
7 a. m - - 
11.04 
93.0 
11.65 
96.8 
13.95 
92.2 
13.91 
95.8 
14.87 
98.3 
8 a. m - 
11.05 
93.0 
11.21 
85.6 
13.96 
93.2 
13. 94 
96.4 
14.02 
78.3 
9 a. m 
11.38 
95.0 
11.25 
81.8 
14. 12 
94.4 
14.03 
13.98 
80.0 
10 a. m 
11.82 
88.2 
11.45 
88.2 
14.10 
94.3 
14.08 
97! 2 
14. 28 
97.5 
11 a. m 
12.30 
89.0 
12.41 
93.2 
14.54 
98.7 
14.50 
97.5 
15.76 
100.0 
12 a. m. 
12.88 
88.3 
13.07 
94.5 
15.04 
15.02 
99.2 
16. 77 
98.3 
1 p. ra. 
13. 51 
99.2 
13. 37 
99.5 
14.99 
100.0 
15.56 
98.9 
17.17 
99.2 
2 p. m 
13.97 
98.7 
14. 14 
15.77 
99.0 
15.80 
96.6 
17.31 
95.7 
3 p. m - 
14.02 
96.0 
14. 21 
99.1 
15. 71 
100.0 
15. 77 
99.4 
' 17. 39 
100.0 
4 p. m 
14.06 
100.0 
13.82 
15.84 
98.0 
15. 94 
100.0 
16.86 
97.8 
5 p. m 
14.22 
100.0 
13.00 
96.4 
15.76 
95.6 
15.79 
99.2 
15.70 
94.3 
6 p. m 
14. 12 
96.3 
13.27 
93. 2 
15.69 
94.5 
15.71 
98.6 
16. 19 
88.6 
7 p. m 
13.83 
99.5 
13.80 
97.3 
15.52 
96.3 
15. 53 
96.7 
16. 99 
95.5 
8 p. m 
13.67 
100.0 
13.79 
97.7 
15.37 
96.7 
15.36 
95.6 
17. 03 
96.4 
9 p. m 
13.22 
100.0 
13.75 
98.6 
15.48 
89.2 
15.47 
97.5 
16.97 
97.8 
10 p. m 
12.97 
99.5 
13. 77 
98.6 
15. 09 
97.8 
15.09 
97.5 
16.98 
98.6 
11 p. m 
12. 69 
96.7 
13.64 
95.0 
15. 18 
94.7 
15. 18 
97.5 
16.77 
97.8 
12 p. m_ 
12.44 
96.6 
13.46 
96.8 
14.75 
94.5 
14.76 
95.0 
16.50 
95.0 
Average 
12.68 
95.70 
12.84 
95.40 
14. 85 
71.40 
14. 88 
97. 17 
16. 09 
95.48 
Maximum 
14.22 
100.0 
13.82 
98.6 
15.84 
98.0 
15.94 
100.0 
17.39 
100.0 
Minimum - - 
11.04 
93.0 
11.21 
85.5 
13.86 
91.8 
13.86 
96.1 
13.98 
80.0 
Difference 
Difference in per cent time open 
3. 18 
7.0 
2. 61 
13.1 
1.98 
6.2 
2.08 
3.9 
3.41 
20.0 
calculated for temperature dif- 
ference P 
4.4 
10.0 
3.75 
11. 73 
Series 10 (7 days) 
i The table gives records of 10 series of experiments showing the percentage of time which the specimens (two in each case) were 
open during each of the daily hours, calculated over the entire period concerned, and the average hourly temperature during the 
same periods. The troughs and crests are given in italicized figures of temperature and of percentage of time open. The summa- 
rized data at the end show the results calculated on the basis of a variation of 2° C. between crests and troughs of the temperature 
waves. The results appear graphically in Figure 6. 
