Studies on artificial control of reproductive cycle in fishes.

1.研究了水温和光周期对淡水鲤科鱼类Honmoroko（Gnathopogon caerulescens）和海水海龙Tobinumeri（Repomucenus beniteguri）繁殖活动的影响。(1)Honmoroko表现出类似的反应与金鱼的环境因素，即光周期依赖于温度和高温抑制性腺成熟。随着水温的升高，短日照更有效地抑制成熟。秋季气温下降时，随着短日照的抑制作用减弱，性腺开始恢复。虽然在春季至初夏的产卵季节，成熟的维持需要长的光周期，但夏季的高温抑制了性腺的活动时，日照仍然很长。(2)春季温度升高（18 ℃以上）时，Tobinumeri开始产卵，温度进一步升高（28 ℃以上）时，Tobinumeri暂时停止产卵。 ...更多信息 秋季温度下降（低于24-25摄氏度），产卵恢复，产卵继续低于14摄氏度。实验发现，与本莫罗科鱼不同，长光周期对本莫罗科鱼的性腺活性有抑制作用.虹鳟亲鱼从3月开始在16 L、18 L和20 L长光周期条件下进行为期一年的饲养。长日照时性腺发育提前，16 L时雌鱼产卵高峰在10月，其余各组产卵高峰在11月。三组雄鼠的排精开始时间均比自然条件组早1个月。有人建议，长光周期处理可以补偿延迟的男性成熟，这是一个问题，许多孵化场已选择早期产卵的女性。3两个实验进行了金鱼。一种是长期暴露于24 ℃或16 ℃与16 L或12 L的组合，另一种是短期暴露于一年内多次从自然条件转移的四种制度。这些实验表明，随着温度的升高，光周期现象变得更加明显，但长光周期对性腺成熟的促进作用是短暂的。高温和长光周期对雌性生殖腺有抑制作用，但对雄性无抑制作用.至于成熟相关激素的血浆水平在honmoroko和金鱼，雌鱼的雌二醇-17 β和雄鱼的睾酮与性腺成熟度，但促性腺激素含量随温度升高，无论成熟阶段。少

1. The effects of water temperature and photoperiod on the reproductive activity were investigated in two fishes, freshwater cyprinid fish Honmoroko (Gnathopogon caerulescens) and seawater dragonet Tobinumeri (Repomucenus beniteguri), as new species. (1) Honmoroko showed a similar response with goldfish to environmental factors, that is, photoperiodism was dependent on temperature and high temperature suppressed gonadal maturation. Short daylength depressed maturation more effectively as water temperature increased. In autumn when temperature decreased, gonadal recrudescence started with the diminution of inhibitory effect of short daylength. Though maintenance of maturation needed long photoperiod in the spawning season of spring to early summer,high temperature in summer suppressed the gonadal activity when daylength was still long. (2) Tobinumeri began to spawn as temperature rose (above 18ﾟC) in spring, and stopped spawning temporally with further rise of temperature (above 28ﾟC). … More Spawning resumed with the fall of temperature in autumn (below 24-25ﾟC), and spawning continued below 14ﾟC. It was noticed experimentally that unlike honmoroko, long photoperiod had suppressive effect on gonadal activity in this fish.2. Rainbowtrout broodstock were reared under long photoperiods, 16L, 18L and 20L for about one year from March. Gonadal recrudescence advanced under long daylength, and at 16L females reached spawning peak in October whereas the peak of other groups were November. The spermiation of males of three groups started one month earlier than those of natural condition group. It was suggested that long photoperiod treatment can compensate the delay of male maturation which is a problem of many hatcheries where early spawning females have been selected.3 Two experiments were conducted with goldfish. One was long term exposure to 24ﾟC or 16ﾟC combined with 16L or 12L, and the other was short exposure to four regimes transferred from natural condition several times in a year. These experiments revealed that photoperiodism became clearer as temperature increased, but enhancement of gonadal maturation by long photoperiod was transient. It was also observed that high temperature and long photoperiod was suppressive to gonads in female but not in male.4. As to the plasma level of maturation related hormones in honmoroko and goldfish, estradiol-17beta of female fish and testosterone of male fish were correlated with degree of gonadal maturation but gonadotropin contents increased with the temperature regardless of maturational stage. Less