Human-mediated global dispersion of Styela plicata (Tunicata, Ascidiacea).
Human-mediated global dispersion of Styela plicata (Tunicata, Ascidiacea).
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DOI：
10.3391/ai.2009.4.1.4
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发表时间：
2009-01-01
影响因子：
1.6
通讯作者：
da Rocha, R. M.
中科院分区：
文献类型：
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作者：
Barros, R. C. de;Rocha, R. M. da;da Rocha, R. M.
纹海鞘（Styela plicata, Lesueur, 1823）是一种独居的海鞘动物，发现于热带和暖温带海洋中受保护的浅水环境中。它的起源是不确定的，因为自从它第一次被描述以来，它已经在几个海洋中被发现，显示出非常广泛的地理分布。虽然在历史上一直被认为是一种世界性的物种，但在过去的几十年里，它在世界上的一些地区被认为是一种引进或入侵物种。本研究调查了褶皱葡萄居群间的遗传变异。总共51个样本来自美国大西洋和太平洋沿岸、日本以及巴西南部和东南部。细胞色素氧化酶亚基I基因（COI）片段的扩增产生了9个不同的单倍型。单倍型的地理分布有很大的差异，但核苷酸和单倍型多样性在太平洋地区明显最高。有趣的是，其中一个单倍型与其他单倍型的差异超过3%，这表明可能是一个隐物种。这些结果，连同历史记录，表明商业航运可能是全球分布的主要原因。西北太平洋地区被假设为该物种的分布中心。
Styela plicata (Lesueur, 1823) is a solitary ascidian found in shallow, protected environments in tropical and warm-temperate oceans. Its origin is uncertain, given that it has already been identified in several oceans since it was first described, showing a very broad geographical distribution. Although S. plicata has been historically classified as a cosmopolitan species, in the past few decades it has been considered as an introduced or invasive species in some regions of the world. The present study investigated the genetic variation among populations of S. plicata. A total of 51 samples were obtained from locations on the Atlantic and Pacific coasts of the USA, Japan, and southern and southeastern Brazil. The amplification of a fragment of the cytochrome oxidase subunit I gene (COI) generated nine distinct haplotypes. There was considerable variation in the geographical distribution of haplotypes, yet the highest nucleotide and haplotypic diversities were clearly found in the Pacific samples. Interestingly, one of the haplotypes showed more than 3% divergence in relation to the remaining haplotypes, suggesting the possibility of a cryptic species. These results, together with historical records, indicate that commercial shipping could be the main cause for the global distribution of S. plicata. The northwestern Pacific region is hypothesized as the center of distribution of the species.