Bodenstein Sarah, Callam Brian R, Walton William C, Rikard F Scott, Tiersch Terrence R, La Peyre Jerome F
Aquatic Germplasm and Genetic Resources Center, School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70820, United States of America.
Louisiana State University and Louisiana Sea Grant Outreach Program, Baton Rouge, LA 70803, United States of America.
Aquaculture. 2023 Feb 15;564. doi: 10.1016/j.aquaculture.2022.739032. Epub 2022 Nov 6.
Triploid Eastern oysters have been reported to suffer greater mortalities than diploids when exposed to low-salinity (<5) conditions in the U.S. Gulf of Mexico and Atlantic estuaries. As such, the effect of broodstock parentage was investigated on the low-salinity tolerance of triploid progeny produced by mating diploid females (collected from three Louisiana estuaries differing in salinity regimes) with male tetraploids at two hatcheries. Diploid crosses were also produced using the wild broodstocks to verify expected differences in low-salinity tolerance among diploid progeny and between ploidy levels. All progeny were deployed at low and moderate-salinity (averages of 9.3 and 19.4) field sites to monitor monthly growth and mortality. Sex ratio, gametogenic stage, gonad-to-body ratio, condition index, and infection were also measured periodically at both field sites Although high triploid mortality at the low-salinity site prevented complete analysis, results indicated that diploid parentage had little effect on triploid survival at low salinity. Broodstock parentage affected diploid mortality and growth, although results did not match with predictions made based on historical salinity at broodstock collection sites. Ploidy level had the largest effect on triploid survival and growth followed by the hatchery site where the oysters were produced.
据报道，在美国墨西哥湾和大西洋河口，三倍体东方牡蛎在暴露于低盐度（<5）条件下时，死亡率高于二倍体。因此，研究了亲鱼亲本对在两个孵化场将二倍体雌性（从三个盐度不同的路易斯安那河口采集）与雄性四倍体交配产生的三倍体后代低盐度耐受性的影响。还使用野生亲鱼进行了二倍体杂交，以验证二倍体后代之间以及倍性水平之间在低盐度耐受性方面的预期差异。所有后代都被放置在低盐度和中等盐度（平均分别为9.3和19.4）的野外场地，以监测每月的生长和死亡率。在两个野外场地还定期测量了性别比例、配子发生阶段、性腺与身体比例、状况指数和感染情况。尽管低盐度场地的三倍体高死亡率妨碍了完整分析，但结果表明二倍体亲本对低盐度下三倍体的存活影响很小。亲鱼亲本影响二倍体的死亡率和生长，尽管结果与基于亲鱼采集地点的历史盐度所做的预测不相符。倍性水平对三倍体的存活和生长影响最大，其次是牡蛎生产的孵化场地点。
