TEMPERATURE AND SHELL MOVEMENTS OF OYSTERS 
3 
Table 1 . — Showing length of time which Olympia oysters remain open 
Experiment 
Specimen 
Hours 
open 
Days 
recorded 
Average 
number 
of hours 
open per 
day 
No. 1 
No. 1 
90. 25 
5 
18. 05 
Do 
No. 2 
103. 20 
5 
20. 64 
Nos. 2 and 3 , 
No. 3 
558. 96 
34 
U6.44 
Do 
No. 4 
675. 24 
34 
U9 . 86 
Nos. 8 and 9 
No. 3 
309. 23 
17 
118. 19 
Do 
No. 4 
317. 56 
17 
118. 68 
Nos. 12 and 13 
No. 3 
188. 80 
23. 60 
Do 
No. 4 
186. 96 
g 
23. 37 
Nos. 16 and 17 
No. 3 .. 
435. 20 
20 
21. 76 
Do — 
No 4 
433. 20 
20 
21 . 66 
Nos. 18 and 19 - 
No. 3 
603. 00 
30 
2 20. 10 
Do 
No. 4 
510. 00 
30 
2 17. 00 
Nos. 20 and 21 - 
No. 3 __ 
695. 97 
33 
21.09 
Do 
No. 4 
702. 57 
33 
21. 29 
Nos. 22 and 23 
No. 3 
31 
22. 21 
Do 
No. 4 
675! 18 
31 
21. 78 
Nos. 24 and 25 
No. 3 
463. 20 
20 
23. 16 
Do - 
No. 4 
462. 00 
20 
23. 10 
Total 
8, 099. 03 
396 
20. 45 
Totals, after elimination of experiments 2-3, 3-9, and 18-19 
5, 125. 04 
234 
21. 90 
■ Low proportion of time open due to temperature fluctuations. 
2 Low proportion or time open due to contamination. 
OCTOBER, NOVEMBER 
Figure 1.— Showing the average number of hours that two specimens of Ostrea lurida were open on each 
of 29 days, and the daily temperature of the water (average of 24 hourly readings) 
EFFECT OF TEMPERATURE 
That some sort of relationship exists between the temperature of the water and 
the length of time oysters remain open is indicated in Figure 1, in which the averaged 
data of the two specimens of experiments Nos. 2 and 3 (Table 1) are presented graphi- 
cally. On the same graph are given the average number of hours which the two speci- 
mens were open on each of the 30 days of the experiment and the average temperature 
for each day calculated by averaging the 24 hourly temperature readings. The series 
