Zoological Laboratory, University of Bergen, N-5000, Bergen, Norway.
Fish Physiol Biochem. 1987 Jan;3(1):17-24. doi: 10.1007/BF02183990.
Measurements of yolk osmolality from the embryo of codGadus morhua L. revealed significant variations in the hyposmolality during the embryonic development. The embryo proved to have an extremely low water permeability, protecting it from dehydration in the hyperosmotic seawater. The effect of temperature on the water permeability is high, expressed by an exceptionally high activation energy for water transfer. The agreement between embryonic volume decrease and diffusion permeability during the first 8-10 days after fertilization indicates that no water uptake mechanism is present at this time, thus leaving the embryo fully dependent on internal water stores. The cod egg is buoyant in seawater throughout development. The mechanism for providing hydrostatic lift is the large volume of diluted tissue water located in the yolk and subdermal spaces.
从鳕鱼（Gadus morhua L.）胚胎中测量卵黄渗透压发现，胚胎发育过程中的低渗度有显著变化。胚胎具有极低的水渗透性，从而防止胚胎在高渗海水中脱水。温度对水渗透性的影响很大，水转移的活化能异常高。受精后 8-10 天内胚胎体积减少和扩散渗透性之间的一致性表明，此时不存在水吸收机制，因此胚胎完全依赖于内部储水。鳕鱼卵在整个发育过程中都在海水中漂浮。提供静水升力的机制是位于卵黄和皮下空间中的大量稀释组织水。
