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X Data
all the embryos were abnormal and just ~5 % reached the early gastrulae stage at 1atm
(Fig. 3.11).
percentage
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5 o C
U 2 48 32
BELA
10 o C
15 o C
20 o C
U 2 48 32 BELA U 2 48 32 BELA U 2 48 32 B ELA
D evelopm ental Stage
200 atm 150 atm 100 atm 50 atm 1 atm
Fig. 3.11. Asterias rubens embryos incubated at 5, 10, 15 and 20° C at 1, 50, 100, 150
and 200 atm for 48 h. Histogram represent % mean and SD. Development stages are
(U) Uncleaved, 2 to 32 cell, (B) Blastula, (E) Early gastrula, (L) Late gastrula and (A)
Abnormal.
Marthasterias glacialis
At 6 h: At 5°C there was no evidence of cleavage at any pressure. At 10°C and
1atm ~80 % of the embryos were uncleaved, at 50atm ~40 % of embryos were at the
4-cell stage, and the remainder were 2-cell or abnormal. At 100atm ~20 % included
2-, 4-, 8-, and 16-cell, ~50 % were uncleaved and ~30 % abnormal. At 150 and
200atm ~90 % were uncleaved, the rest were abnormal. At 15°C and 1 atm ~80 % of
the embryos were at 8-cell, at 50atm ~50 % were 16-cell and ~40 % were abnormal,
at 100 and 150atm ~70 % was distributed among 2-, 4-, 8-, and 16-cell stages and
~30 % were abnormal, at 200 atm ~90 % of zygotes were uncleaved and ~10 were
abnormal. At 20°C from 1 to 150atm the number of embryos at 32-cell was
decreasing from ~70 to ~ 20 %, the number of abnormal embryos increased with the
pressure from ~30 % at 1atm to ~80 % at 150 atm, at 200atm ~9 % were abnormal
and the rest uncleaved (Fig. 3.12).
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