Octocoral Species Assembly and Coexistence in Caribbean Coral Reefs.
Octocoral Species Assembly and Coexistence in Caribbean Coral Reefs.
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DOI：
10.1371/journal.pone.0129609
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Sánchez JA
中科院分区：
文献类型：
--
作者：
Velásquez J;Sánchez JA
在海洋中最多样化的生态系统中，群落聚集的决定因素是什么？珊瑚礁可以分为大陆型（即，在大陆架上发育的珊瑚礁，包括硅质珊瑚礁）和海洋（即，远离大陆架，通常在火山底层）;这些生境差异是否会造成整个群落的生态分化或物种排斥/共存，从而产生进化后果，尚不清楚。以加勒比海珊瑚为模型系统，研究了珊瑚礁群落的系统发育群落结构，强调了物种共存的特征进化和环境反馈。利用线粒体DNA构建的系统发育树，共包含5科49种鱼类。我们包括了来自西加勒比（哥伦比亚）11个地方的数据，包括大多数珊瑚礁类型。为了测试多样性环境和表型环境的关系，系统发育的社区结构和性状进化，我们进行了比较分析，实现生态和进化的方法。系统发育推断表明海洋珊瑚礁的集群（例如，环礁）与大陆珊瑚礁的系统发育过度分散（例如，礁滩）。此外，环礁和堡礁有最高的物种多样性（香农指数），而系统发育多样性较高的礁银行。判别成分分析支持这种分化的海洋和大陆的珊瑚礁，大陆珊瑚物种往往有更大的花萼孔径，更厚的分支，突出的花萼和azooxanthellate物种。这项分析还表明，斜坡和其余的栖息地之间的明显分离，所造成的共生藻的存在或不存在。K统计分析表明，该性状与分支形状一样保守。大洋礁与大陆礁之间存在着强有力的珊瑚群落结构，其多样性和组成模式相反。即使是深度和总体环境条件相似的生境，在海洋和大陆珊瑚礁之间也没有类似的群落。这表明对当地社区的强烈区域影响，可能是由于主要珊瑚礁类型之间的水透明度差异，即，海洋与大陆架浅海。这是支持的对比模式中发现的形态，组成和进化历史的物种之间的环礁和珊瑚礁银行。
What are the determinant factors of community assemblies in the most diverse ecosystem in the ocean? Coral reefs can be divided in continental (i.e., reefs that develop on the continental shelf, including siliciclastic reefs) and oceanic (i.e., far off the continental shelf, usually on volcanic substratum); whether or not these habitat differences impose community-wide ecological divergence or species exclusion/coexistence with evolutionary consequences, is unknown. Studying Caribbean octocorals as model system, we determined the phylogenetic community structure in a coral reef community, making emphasis on species coexistence evidenced on trait evolution and environmental feedbacks. Forty-nine species represented in five families constituted the species pool from which a phylogenetic tree was reconstructed using mtDNA. We included data from 11 localities in the Western Caribbean (Colombia) including most reef types. To test diversity-environment and phenotype-environment relationships, phylogenetic community structure and trait evolution we carried out comparative analyses implementing ecological and evolutionary approaches. Phylogenetic inferences suggest clustering of oceanic reefs (e.g., atolls) contrasting with phylogenetic overdispersion of continental reefs (e.g., reefs banks). Additionally, atolls and barrier reefs had the highest species diversity (Shannon index) whereas phylogenetic diversity was higher in reef banks. The discriminant component analysis supported this differentiation between oceanic and continental reefs, where continental octocoral species tend to have greater calyx apertures, thicker branches, prominent calyces and azooxanthellate species. This analysis also indicated a clear separation between the slope and the remaining habitats, caused by the presence or absence of Symbiodinium. K statistic analysis showed that this trait is conserved as well as the branch shape. There was strong octocoral community structure with opposite diversity and composition patterns between oceanic and continental reefs. Even habitats with similar depths and overall environmental conditions did not share similar communities between oceanic and continental reefs. This indicates a strong regional influence over the local communities, probably due to water transparency differences between major reef types, i.e., oceanic vs. continental shelf-neritic. This was supported by contrasting patterns found in morphology, composition and evolutionary history of the species between atolls and reef banks.