抄録
In order to clarify the period during which eggs and sperm of Oryzias latipes remained viable following release into fresh water, the fertilization rate of eggs over time following immersion in fresh water, was investigated, in addition to sperm motility. Fertilizability of the eggs persisted for more than 6 minutes after immersion , but was lost after more than 10 minutes in some cases. Sperm retained motility for about 2–3 minutes in fresh water, being affected by osmolality; motility was high in 100–300 mOsm/kg, but absent in 700 mOsm/kg. These results suggested that O. latipes eggs can be fertilized for up to 6 minutes following spawning in fresh water, whereas sperm remain viable for only 2–3 minutes following released.
