1995 Fiscal Year Final Research Report Summary
Studies on freezing torelance of embryo and larvae of aquatic animals
| Project/Area Number |
06454098
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General fisheries
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| Research Institution | The University of Tokyo |
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Principal Investigator |
KUROKURA Hisashi The University of Tokyo, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (50134507)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Freezing tolerance / Aquatic animal / Rotifer / Trochophore / Nauplius / Fish embryo / Barnacles / Bivalve |
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| Research Abstract |
Freezing tolerance of embryo or larvae was compared among aquatic animals. Amictic female egg of rotifer could successfully be cryopreserved in liquid nitrogen and could grow to spawner after thawing Freezing tolerance of the embryo varied during embryonic development. The highest freezing tolerance was observed at symmetrical embryo atage. Trochophore stage larvae obtained from blue mussel also survived after preservation in liquid nitrogen and they reached veliger stage. In case of nauplius larvae of barnacles, activity of survivor in liquid nitrogen was very low and only small portion of survior grew to setting individuals. Dehydration from nauplius larvae during first slow cooling was supposed to be a determinant of survival by second rapid cooling. Any survival could not be observe after cooling to -196ﾟC in flounder and seabream eggs. Formation of auditory vesicle stage embryo and later stage embryo of flounder could survive after cooling to -20ﾟC,when they were thawed just after reaching at the temperature. However, Sea bream embryo at the developmental stage could survie for only 15 min. at -20ﾟC.Conclusively, smaller embryo or larva has higher freezing tolerance than larger animal when compared interspecifically, though freezing tolerance of them are varies during development even in same species. Gene bank by cryopreservation of embryo or larvae seems to be possible in the animal of which size is smaller than 0.3mm.
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