Production of triploid eastern little tuna, Euthynnus affinis (Cantor, 1849)
Production of triploid eastern little tuna, Euthynnus affinis (Cantor, 1849)
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三倍体东部小金枪鱼 Euthynnus affinis 的生产（Cantor，1849）
DOI：
10.1111/are.14017
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发表时间：
2019
影响因子：
2
通讯作者：
Yoshizaki G.
中科院分区：
文献类型：
--
作者：
Yazawa R;Takeuchi Y;Machida Y;Amezawa K;Kabeya N;Tani R;Kawamura W;Yoshizaki G.
本研究利用东部小金枪鱼（Euthynnus affinis）产卵后立即收集的产卵卵，建立了一种三倍体化方法。ELT亲鱼经激素处理后在池中诱导产卵，所得卵用于三倍体诱导。在最佳条件下，平均±半三倍体化率和孵化率分别为97.2±2.8%和84.5±10.3%。虽然三倍体ELT的生长性能与二倍体相当，但当三倍体和二倍体在同一水箱中饲养时，三倍体在孵化后2-4周内的死亡率高于二倍体。因此，我们认为在实际操作中，有必要使用纯三倍体的ELT幼苗，以避免二倍体的选择性同类相食。ELT三倍体表现为全雌性表型。因为先前的研究报道，女性三倍体比男性三倍体表现出更大的不育可能性，这一特征可能是一个主要的优势。由于这种使用产卵卵的三倍体化方法可以在不处理亲鱼的情况下进行，因此可以避免人工授精过程中造成的物理损伤，从而可以重复产生三倍体种群而不会损失有价值的亲鱼。因此，我们已经开发了一种高效的ELT三倍体的制备方法，尽管对三倍体ELT的不育性评价还需要进一步的研究。
Herein, we developed a triploidization method using spawned eggs collected immediately after spawning of eastern little tuna (ELT),Euthynnus affinis. ELT broodstock induced the spawning by hormonal treatment in the tank, with the resulting spawned eggs being used for the triploidy induction. Under optimal conditions, the mean ±SEMtriploidization and hatching rates were 97.2 ± 2.8% and 84.5 ± 10.3%, respectively. Although triploid ELT showed growth performance equivalent to that of diploids, the triploids died at a higher rate than the diploids during 2–4 weeks post‐hatching when triploids and diploids were reared in the same tank. Therefore, we propose that it would be necessary in a practical operation to use triploid‐only ELT seedlings to avoid selective cannibalism by the diploids. The ELT triploids exhibited an all‐female phenotype. Because previous studies have reported that female triploids show a greater probability of sterility than male triploids, this characteristic could be a major advantage. Since this triploidization method, using spawned eggs, can be performed without handling the broodstock, it is possible to avoid the physical damage caused by the process of artificial insemination, making it possible to repeatedly produce triploid populations without valuable broodstock loss. Thus, we have developed an efficient method to produce ELT triploids, although further study is essential to evaluate sterility of the triploid ELT.