Maturation and Spawning of Flounder (Paralichthys olivaceus) under Captive Conditions

The flounder reared in captivity matured and spawned when the water temperature gradually increased to from during winter and the diurnal photoperiod changed from 10L/14D in winter season to 14L/10D in spring. The eggs spawned naturally by reared spawners in captivity during the first half of a spawning period were superior in quality to those spawned during the later half. It would be better to use the eggs of the first half for the mass production of the seedlings.