Niche differences in co-occurring cryptic coral species (Pocillopora spp.)
Niche differences in co-occurring cryptic coral species (Pocillopora spp.)
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DOI：
10.1007/s00338-021-02107-9
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发表时间：
2021-05
期刊：
影响因子：
3.5
通讯作者：
Erika C. Johnston;A. Wyatt;J. Leichter;S. C. Burgess
中科院分区：
文献类型：
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作者：
Erika C. Johnston;A. Wyatt;J. Leichter;S. C. Burgess
形态相似的神秘物种之所以共存，是因为竞争排斥的速度非常慢，或者因为它们实际上在生态上并不相似。因此，维持隐蔽的地方多样性的过程可能特别微妙和难以识别。在这里，我们发现了几个神秘物种之间的差异，在一个优势的和生态上重要的硬珊瑚属，Pocillopora的深度梯度上它们的相对丰度。通过在法属波利尼西亚莫雷亚岛周围的前礁上的多个深度对形态特征进行无偏倚的广泛采样，我们在遗传上鉴定了泡孔虫种复合体中的673个殖民地。我们鉴定了14种线粒体开放阅读框架单倍型(mtORFs，一种用于囊足动物的研究充分和信息丰富的物种标记)，其中至少包括6个标称物种，并在岛周围4个地点发现了单倍型在5、10和20m处的相对丰度差异。不同深度的相对单倍型丰度的差异大于相隔几公里的地点之间的差异。这四个最丰富的物种通常在总体种群水平上看起来很难区分，但它们在与光照和每日水温变化的关联上表现出明显的差异。群落组成的格局与较深水域和较浅水域的频繁降温有关，而不是与浅水温度较高有关。我们的结果表明，这些神秘的物种在生态上并不都是相似的。不同深度的孔虫物种的不同丰度应该会促进它们在珊瑚礁规模上的共存，并通过响应多样性促进复原力。
Cryptic species that are morphologically similar co-occur because either the rate of competitive exclusion is very slow, or because they are not, in fact, ecologically similar. The processes that maintain cryptic local diversity may, therefore, be particularly subtle and difficult to identify. Here, we uncover differences among several cryptic species in their relative abundance across a depth gradient within a dominant and ecologically important genus of hard coral,Pocillopora. From extensive sampling unbiased toward morphological characters, at multiple depths on the fore reef around the island of Mo’orea, French Polynesia, we genetically identified 673 colonies in thePocilloporaspecies complex. We identified 14 mitochondrial Open Reading Frame haplotypes (mtORFs, a well-studied and informative species marker used for pocilloporids), which included at least six nominal species, and uncovered differences among haplotypes in their relative abundance at 5, 10, and 20 m at four sites around the island. Differences in relative haplotype abundance across depths were greater than differences among sites separated by several kilometers. The four most abundant species are often visibly indistinguishable at the gross colony level, yet they exhibited stark differences in their associations with light irradiance and daily water temperature variance. The pattern of community composition was associated with frequent cooling in deeper versus shallower water more than warmer temperatures in shallow water. Our results indicate that these cryptic species are not all ecologically similar. The differential abundance ofPocilloporacryptic species across depth should promote their coexistence at the reef scale, as well as promote resilience through response diversity.