As coral reefs experience dramatic declines in coral cover throughout the tropics, there is an urgent need to understand the role that non-reef habitats, such as mangroves, play in the ecological niche of corals. Mangrove habitats present a challenge to reef-dwelling corals because they can differ dramatically from adjacent reef habitats with respect to key environmental parameters, such as light. Because variation in light within reef habitats is known to drive intraspecific differences in coral phenotype, we hypothesized that coral species that can exploit both reef and mangrove habitats will exhibit predictable differences in phenotypes between habitats. To investigate how intraspecific variation, driven by either local adaptation or phenotypic plasticity, might enable particular coral species to exploit these two qualitatively different habitat types, we compared the phenotypes of two widespread Caribbean corals, Porites divaricata and Porites astreoides, in mangrove versus lagoon habitats on Turneffe Atoll, Belize. We document significant differences in colony size, color, structural complexity, and corallite morphology between habitats. In every instance, the phenotypic differences between mangrove prop root and lagoon corals exhibited consistent trends in both P. divaricata and P. astreoides. We believe this study is the first to document intraspecific phenotypic diversity in corals occupying mangrove prop root versus lagoonal patch reef habitats. A difference in the capacity to adopt an alternative phenotype that is well suited to the mangrove habitat may explain why some reef coral species can exploit mangroves, while others cannot.

中文翻译：

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与两种广泛分布的加勒比海珊瑚，Porites astreoides和Porites divaricata的红树林和泻湖栖息地有关的不同表型

随着整个热带地区珊瑚礁的覆盖率急剧下降，迫切需要了解诸如红树林之类的非珊瑚礁栖息地在珊瑚生态位中的作用。红树林栖息地对居住在珊瑚礁中的珊瑚提出了挑战，因为就关键环境参数（例如光）而言，它们与相邻的珊瑚礁栖息地可能有很大差异。因为已知珊瑚礁栖息地内光线的变化会导致珊瑚表型的种内差异，所以我们假设可以利用珊瑚礁和红树林栖息地的珊瑚物种在生境之间表现出可预测的表型差异。要研究局部适应或表型可塑性驱动的种内变异，伯利兹Turneffe环礁的红树林与泻湖生境中的Porvari divaricata和Porites astreoides。我们记录了栖息地之间的殖民地大小，颜色，结构复杂性和珊瑚岩形态的显着差异。在每种情况下，红树林支撑根和泻湖珊瑚之间的表型差异在P. divaricata和P. astreoides中均表现出一致的趋势。我们认为，这项研究是第一个记录占据红树林支撑根与珊瑚的物种内表型多样性的文献。泻湖斑块礁生境。采用非常适合红树林生境的替代表型的能力差异可能解释了为什么某些礁石珊瑚物种可以利用红树林，而另一些却不能。