422
KOHMAN Y. ARAKAWA
Crassostrea
c
2 L: 8 0 1
c
8 80
L
1 Exp. NO.
i 60
Exp. No. 1
In
Mytilus
FIG. 27. Comparison of relative volumes of water transport supplied by Crmsostyea and
Myt&ts during the period of light and darkness (Arakawa et d).
TABLE VIII. DAILY RATES OF WATER TRANSPORT IN Crassostrea AND Mytilus
T' ol. of
1'01. of
water
water
Fater
Total
transRatio
temperavolumes
ported
ported
( n : d )
lure
(night) (daytime)
("C)
cc
CC
ee
_ _ _ _ _ . _ _
- ~
___
_ _ ~ _ _ _ _ _ _ _ _
E x p . No.
I
Crassostrea gigas
3 600
3 150
6 750
8 : 7
24.0-26.2
M . galloprovincialis
1 500
600
2 100
5 : 2
24.0-26.2
E x p . N o .
I1
Crassostrea gigas
79 875
21 150
101 000
355: 94
26.0
M. galloprovincialis
9 000
3 000
12 000
3 : 1
24.4-25.9
E x p . No.
I11
Crassostrea gigas
-
-~
-
-
-
M. galloprovincialis
13 200
2 4 0 0
15F00
11 : 2
24.8-25.4
Seasonal aspects
Haven and Morales-Alamo (1966) showed that quantities of faeces
and pseudofaeces produced by oysters (C. virginica) varied seasonally,
reaching maxima in September, and that during winter with the