Abstract：
The widespread decline of shallow-water coral reefs has fueled interest in assessing whether mesophotic reefs can act as refugia replenishing deteriorated shallower reefs through larval exchange. Here we explore the morphological and molecular basis facilitating survival of planulae and adults of the coral Porites astreoides (Lamarck, 1816; Hexacorallia: Poritidae) along the vertical depth gradient in Bermuda. We found differences in micro-skeletal features such as bigger calyxes and coarser surface of the skeletal spines in shallow corals. Yet, tomographic reconstructions reveal an analogous mineral distribution between shallow and mesophotic adults, pointing to similar skeleton growth dynamics. Our study reveals patterns of host genetic connectivity and minimal symbiont depth-zonation across a broader depth range than previously known for this species in Bermuda. Transcriptional variations across life stages showed different regulation of metabolism and stress response functions, unraveling molecular responses to environmental conditions at different depths. Overall, these findings increase our understanding of coral acclimatory capability across broad vertical gradients, ultimately allowing better evaluation of the refugia potential of mesophotic reefs.
摘要：
浅水珊瑚礁的广泛减少激发了人们对评估中观珊瑚礁是否可以充当避难所的兴趣，通过幼虫交换来补充恶化的浅礁。在这里，我们探索了促进珊瑚Poritesastreoides（Lamarck，1816年；Hexacorallia：百慕大的Poritidae）。我们发现了浅珊瑚中骨骼刺的微观骨骼特征，例如更大的花萼和粗糙的表面。然而，层析成像重建揭示了浅层和介观成虫之间类似的矿物分布，指向类似的骨骼生长动力学。我们的研究揭示了宿主遗传连通性和最小共生体深度分区的模式，其深度范围比百慕大该物种先前已知的深度范围更广。不同生命阶段的转录变化显示出代谢和应激反应功能的不同调节，深入揭示分子对环境条件的反应。总的来说,这些发现增加了我们对珊瑚在宽垂直梯度上的适应能力的理解，最终可以更好地评估中隔珊瑚礁的避难所潜力。
