A biological study of Durvillaea antarctica (Chamisso) Hariot and D ...

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A large number of ova at 20°C disintegrated shortly after they h'ere
released, whereas this was relatively uncommon at the lower
temperatures. After 120 minutes, a small piece of ripe male lamina
was added to each dish, and all 30 dishes were kept at 10-ll~e in a
Two days later the oosphere3 were examined.
Almost all the oospheres in the 20°C dishes had disintegrated, and
none appeared to be germil~ting. A large proportion of the oospheres
in the SoC and 11°C dishes however, looked perfectly healthy, and
were germinating.
Table 6.3
Subjective rating of gamete release at three temperatures.
Number of samples used in each treatment '= 10.
(a)
Nl..l1nber rated as "high" or "medium" release:
Species
Temperature
11°C
D. antarctica
6
9
1
D. willana
4
10
o
(b)
Number rated as "very 10'."" or "nil" release:
D. antarctica
1
o
S
D. wiUana
3
o
10
Table 6.4 Frequency of D. antarctica gametes released at three
temperatures. Mea.n number of ova counted using line intercept
method.
Sample number
Temperature
SOC
lloe
20 0 e
1 2100
:2 8.1
3 38.6
4 2.7
5 13.9
6 75.3
7 5.8
8 40.J.
9 20.5
10 8.5
23.5 ±
35.0 1.3
32.0 1.5
14.8 8.0
20.0 4.0
21. 3 9.0
52.3 18.9
40.0 4.5
71.0 28.3
21.1 17 .8
9./l 3 .. 6
3L7 ± 9,.6 1: