小笠原諸島父島におけるイシガキダイの親魚養成と採卵
2007 年 55 巻 1 号 p. 135-136
詳細
2007 年 55 巻 1 号 p. 135-136
The spawning of captive-reared spotted parrot fish Oplegnathus punctatus obtained from rocky shore waters around Chichi-jima, one of the Ogasawara Islands, was observed during rearing between 2002 and 2003. The two females which participated in the spawning were 3.2 and 4.5 kg in BW. Spawnings were observed on 18 occasions between late April and late June. The water temperature in the entire period varied between 18.8°C and 29.6°C whereas that on the spawning days varied between 21.1°C and 24.6°C. The total number of eggs taken was approximately 7 million. The average rate of buoyant eggs was 82.5±23.7%. The average diameter of the egg and oil globule were 1.045±0.017 mm and 0.245±0.006 mm, respectively.
