大黄鱼的人工繁殖研究

Studies on the Artificial Propagation of the Large Yellow Croake, Pseudosciaena crocea (Richardson)

用人工培育成熟的大黄鱼亲鱼于1989—1990年进行人工繁殖研究首次获得成功。实验结果表明,在越冬期(12月)将亲鱼移入室内强化培育,同时注射低剂量LRH-A促进性腺发育,大部分亲鱼在4月中旬至6月初产卵受精。常用催产剂为LRH-A;新型催产剂DOM+SGnRH显得特异效果,催产率在90％以上,大黄鱼的雌雄鱼在发情时会发出“咕—咕—咕”的求偶声,集群追逐。一次催产分批产卵,持续2—3天产完。产卵时间均在晚上9时至凌晨3时之间,天明即停止.在水温20—22℃,海水盐度18.9‰—29.5‰条件下,受精卵经35小时孵出仔鱼。但较低的盐度(20.2‰以下)将影响受精卵的浮性。

The experiment of this study had been carried out in 1989 and 1990. The parent fishes were artificially cultured in the floating net cages on the sea over three years. They were moved into indoor sponds in Decemder, and kept in fit temperature (16℃) with favorable feeding and injected small dosage of LRH-A every 15—20 days for 3—4 times. The method seemed to be very effective on promoting the gonadal development and increasing the mature rate of the parents, especially for fishes of 3—4 years old.There were two breeding seasons for the Large Yellow Croake in a year. Most of the fishes were induced to spawn from middle April to early June. During the oestrus, the males and the females both gave a 'Go—Go—Go' sound, soon the females would lay eggs in batches. The behavior would last for 2—3 days until all mature eggs were spawned. The spawning took place at about 9:00 in the evening till 3:00 next morning, 36 hours after injection of LRH-A or DOM_+ SGnRH. The eggs were naturally fertilized in the spond water, and hatched in about 35 hours under the condition of temperature 20—22℃ and salinity 18.9—22.9‰. Lower salinity (below 20.2‰) would greatly influence the development and floatability of the eggs.