Sexual reproduction in corals is pivotal for the survival of populations in the face of climate change. Off Jeju Island, which lies off the south coast of Korea, a high-latitude scleractinian coral, Alveopora japonica, has experienced a population explosion over the past couple of decades (at 5–15 m depths). A second species, Oulastrea crispata, which is generally present at high latitudes and extreme environments, has a stable population and dominates in the shallow subtidal waters of southern Jeju. This study examined the annual gametogenesis patterns of A. japonica off the north (33°24′N, 126°13′E) and south (33°14′N, 126°36′E) coasts of Jeju Island, and of O. crispata in the south. Histological analysis revealed that the oogonia and spermatogonia in A. japonica developed in separate mesenterial filaments, while the gonads in O. crispata developed in the same filament. Alveopora japonica had the same brooding period during late summer and early fall (Aug–Sep 2015) at both sites. The spawning period of O. crispata was also during late summer and early fall. Brooding in A. japonica was concordant with previous observations of its planula during the brooding period. This study provides the first data on the timing of reproduction of these two high-latitude corals from Jeju Island, which may help our understanding of the population dynamics of corals in other high-latitude environments.

中文翻译：

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来自韩国济州岛的两个高纬度珊瑚Alveopora japonica和Oulastrea crispata的年度配子发生模式

面对气候变化，珊瑚的有性繁殖对于种群的生存至关重要。在韩国南海岸附近的济州岛外，高纬度巩膜珊瑚Alveopora japonica在过去的几十年（5至15 m深度）经历了种群爆炸。第二种，Oulastrea crispata，通常存在于高纬度和极端环境中，种群稳定，在济州南部的浅潮下水域占主导地位。本研究的年度配子模式A.粳稻北奔（33°24'N，126°13'E）和南部（33°14'N，126°36'E），济州岛的海岸，以及Ø薄脆饼干在南方。组织学分析表明，粳稻中的卵原和精原细胞分别在肠系膜细丝中发育，而O.crispata中的性腺在同一条细丝中发育。夏末和初秋（2015年8月至2015年9月）这两个地点的粳稻孵化期相同。O.crispata的产卵期也在夏末和初秋。粳稻的孵化与在育卵期以前对其扁平虫的观察一致。这项研究提供了有关从济州岛上这两种高纬度珊瑚繁殖时间的第一批数据，这可能有助于我们了解其他高纬度环境中珊瑚的种群动态。