STUDIES ON THE VARIATION AND ADAPTATION OF FISHES : I. ADAPTATION OF KILLIFISH(ORYZIAS LATIPES T.&S.)TO SALINE WATER : 2. PRELIMINARY REPORT OF AN EXPERIMENTAL STUDY

Abstract

1. When the fresh water killifish(Oryzias latipes T.&S.)was put into artificial sea water suddenly, it died within a short time, but when it was acclimatized gradually to increasing concentrations of salinity, it could survive even in 51‰ of salinity. (Figs. 1,2. Tables 1,2) 2. The fishes adapted to the artificial sea water could lay eggs, but they did not hatch. The spawning time of the adapted fishes began two months later in a year than that of the normal fishes. 3. The adapted fishes showed no change within 48 hours, when they were suddenly put into fresh water from the artificial sea water. (Table 3)Juding from the facts described above, it can be seen that the adaptability of the killifish to saline water is very great.