海棲メダカの研究 : III.受精並びに発生に対する塩分濃度の影響

概要

論文の詳細を見る
1. Fertilization of the egg of fresh water Medaka did not take place in sea water which was more concentrated than 28.5g/l in salinity. In sea water, fertilizability of the egg was kept about two hours, and that of spermatozoa was reduced remarkably in 15-30 minutes and lost in 60 minutes. 2. When the eggs were inseminated in sea water and kept for 30-60 minutes therein and then they were transferred into M/7.5 Ringer solution, fertilization not take place. But when they were reinseminated in M/7.5 Ringer, some of them were fertilized. The percentage of fertilization in this case was coincided with that of fertilizability of the eggs in sea water. 3. When the eggs of fresh water or sea water Medaka were inseminated in sea water with the sperm of sea water Medaka, some of them were fertilized. From these facts and the observations of mobility of spermatozoa in sea water, the difficulty of fertilization of fresh water Medaka in sea water is assumed to be attributable to immobility of the spermatozoa in sea water. 4. In sea water early cleavage of the fertilized egg was retarded slightly, and most of them were disintegrated at the gastrula stage. 5. As already reported, from June to July, the salinity of the surface of sea in Amakusa Matsushima, Kumamoto prefecture showed a decrease in the common concentration by half. Therefore in this environment, the egg of Medaka may be able to fertilize and develop.
社団法人日本動物学会の論文
1962-04-15