UBC Theses and Dissertations
The effects of some constant and some changing conditions of salinity on the development and mortality of the eggs and larvae of the Pacific Herring Clupea pallasii Cuvier McMynn, Robert Graham
Methods were developed for the successful artificial fertilization and rearing of the eggs and larvae of the Pacific herring, Clupea pallasii Cuvier. Effects of various constant and changing conditions of salinity (0 ‰ to 34.28 ‰) on the development, mortality and hatching of eggs and on the mortality of larvae were studied. Evidence of an optimum salinity, 11.55 ‰ to 16.24 ‰, for development and survival of eggs is presented, although a wide salinity tolerance, 6.06 ‰ to 34.28 ‰ for both eggs and larvae is evident. Eggs transferred to pond water (0 ‰ salinity) during the first few days of development, perish within a few hours, but if transferred at a later stage, they will survive for at least two days. No apparent correlation exists between survival of eggs and magnitude of salinity change. The presence of two critical stages during embryonic development, the first at blastopore closure, the second prior to and during hatching, have been shown. An optimum survival of eggs was obtained on egg slide sections containing from 75 to 125 eggs.
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