Induction of sexual maturation of the female honeycomb grouper, Epinephelus merra, in the non-breeding season by modulating environmental factors with GnRH analogue implantation.
Induction of sexual maturation of the female honeycomb grouper, Epinephelus merra, in the non-breeding season by modulating environmental factors with GnRH analogue implantation.
复制标题
通过植入 GnRH 类似物来调节环境因素，在非繁殖季节诱导雌性蜂窝石斑鱼 (Epinephelus meerra) 性成熟。
DOI：
10.1016/j.aquaculture.2012.06.026
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发表时间：
2012
期刊：
影响因子：
4.5
通讯作者：
H. Kagawa
中科院分区：
文献类型：
--
作者：
T. Kanemaru;M. Nakamura;R. Murata;K. Kuroki;H. Horie;K. Uchida;B. Senthilkumaran;H. Kagawa
与日本任何其他经济上重要的食用鱼水产养殖实践一样，石斑鱼养殖也具有重要意义。在适当的时间定期提供性成熟亲鱼和稳定的苗种生产被认为对于多产鱼类养殖至关重要。尽管之前的研究已经在一些卵巢具有卵黄发生或完全成熟的成熟卵母细胞的石斑鱼物种中诱导了性成熟和产卵，但很少有人关注在非产卵季节人工诱导未成熟鱼的性成熟和产卵。开发这种方法将极大地促进石斑鱼养殖业的发展。为了促进这项任务，我们使用一种流行的实验模型鱼——蜂窝石斑鱼，通过使用渗透泵植入促性腺激素释放激素类似物（GnRHa）来调节环境因素，从而在非繁殖季节诱导性成熟。我们在人工/自然光热条件下，在植入或不植入 GnRHa 的情况下，在非繁殖季节的不同时期进行了三个不同的实验。除了性腺体细胞指数和血浆雌二醇水平的数据之外，还通过各种处理后卵黄形成成熟卵母细胞的存在来对性成熟的诱导进行评分。在各种处理中，高水温和长光周期条件在10月至12月期间诱导了未成熟石斑鱼的性成熟。在本研究测试的非繁殖季节的所有时期，将 GnRHa 植入这些鱼类中都会诱导性成熟。事实上，属于这些群体的一些鱼类甚至在治疗过程中产卵，这表明治疗的有效性。另一方面，单独植入 GnRHa 或暴露于自然光热条件下都不会引起性成熟。同样，在持续时间内将短光周期和长光周期与从低到高的水温暴露相结合被发现无论是否植入 GnRHa 都效果最差。同样，仅暴露于长光周期或高水温并不能诱导性成熟。因此，人工光热条件与 GnRHa 植入的结合似乎是诱导未成熟鱼性成熟的决定性方法。基于这些结果，我们展示了通过植入 GnRHa 来调节环境变量，在非繁殖季节成功繁殖性成熟海洋硬骨鱼的优越策略。
Grouper culture assumes importance like any other economically important food fish aquaculture practice in Japan. Regular availability of sexually mature brood stock at appropriate time and stable seed production are considered vital for prolific fish farming. Despite the fact that previous studies have induced sexual maturation and spawning in some grouper species that had ovaries with vitellogenic or full-grown mature oocytes, little attention has been paid to artificial induction of sexual maturation and spawning of immature fish in off-spawning season. Developing such a method will promote grouper aquaculture immensely. In an aim to facilitate such a task, we used one of the popular experimental model fishes, the honeycomb grouper, Epinephelus merra, to induce sexual maturation during non-breeding season by modulating environmental factors with gonadotropin-releasing hormone analogue (GnRHa) implantation using osmotic pump. We performed three different experiments flanking various periods of non-breeding season under artificial/natural photothermal conditions with or without GnRHa implantation. Induction of sexual maturation is scored by the presence of vitellogenic to mature oocytes after various treatments in addition to the data of gonado-somatic index and plasma estradiol levels. Among various treatments, high water temperature with long photoperiod conditions induced sexual maturation in immature groupers during October to December. Implantation of GnRHa to these fishes induced sexual maturation at all periods of non-breeding season tested in this study. In fact some of the fishes belonging to these groups have even spawned during the course of treatment indicating the effectiveness of the treatments. On the other hand, neither GnRHa implantation alone nor exposure to natural photothermal conditions evoked sexual maturation. Likewise, combination of short and long photoperiod with low to high water temperature exposure over the duration period was found to be least effective with or without GnRHa implantation. Similarly, exposure to long photoperiod or high water temperature alone did not induce sexual maturation. Hence, combination of artificial photothermal conditions with GnRHa implantation seems to be a decisive method to induce sexual maturation in immature fish. Based on these results, we demonstrate a superior strategy for successful breeding of sexually immature marine teleost fish during non-breeding season by modulating environmental variables with GnRHa implantation.