Out of Alaska: morphological diversity within the genus Eurytemora from its ancestral Alaskan range (Crustacea, Copepoda)
Out of Alaska: morphological diversity within the genus Eurytemora from its ancestral Alaskan range (Crustacea, Copepoda)
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DOI：
10.1007/s10750-010-0351-3
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发表时间：
2010-10-01
期刊：
影响因子：
2.6
通讯作者：
Lee, Carol Eunmi
中科院分区：
文献类型：
--
作者：
Dodson, Stanley I.;Skelly, Daniel A.;Lee, Carol Eunmi
宽尾桡足类在整个北方半球占据了广泛的生境类型，是所有已知桡足类中盐度范围最广的。该属的多样性中心位于沿着阿拉斯加，那里有几个物种是特有的。系统分析一直很困难，但是，因为在这属的形态停滞的趋势，尽管大的遗传差异之间的种群和物种。本研究的目的是（1）分析该属内的形态变异和分歧模式，重点是在北美的Eurytemora物种，和（2）确定Eurytemora物种在阿拉斯加祖先范围内的地理和盐度分布模式。我们应用了比较多变量形态分析，使用16-26字符从125个标本20个新收集的网站在阿拉斯加和15个现有的样品主要来自北美。通过主成分分析和系统聚类分析，确定了北美宽尾藻属7个形态特征明显的种。affinis、E. americana、美洲虎斑叶蝉E. canadensis、加拿大拟步行虫E. composita、E. Eschermani，E. pacifica和E. raboti），并确定了区分该物种的诊断特征（形成了新识别码的基础）。一些以前命名的物种被认为是同义词。我们在阿拉斯加取样的地点在宽尾龙属物种的高水平同域分布方面是引人注目的，在阿拉斯加以外的地方没有看到过。未来的研究Eurytemora应阐明的模式，栖息地入侵和生理进化属内，并产生深入了解的机制，导致其非常广泛的地理和栖息地范围。
The copepod genus Eurytemora occupies a wide range of habitat types throughout the Northern Hemisphere, with among the broadest salinity ranges of any known copepod. The epicenter of diversity for this genus lies along coastal Alaska, where several species are endemic. Systematic analysis has been difficult, however, because of a tendency toward morphological stasis in this genus, despite large genetic divergences among populations and species. The goals of this study were to (1) analyze patterns of morphological variation and divergence within this genus, focusing on Eurytemora species that occur in North America, and (2) determine patterns of geographic and salinity distribution of Eurytemora species within the ancestral range in Alaska. We applied a comparative multivariate morphological analysis using 16-26 characters from 125 specimens from 20 newly collected sites in Alaska and 15 existing samples predominantly from North America. Results from principal component and hierarchical cluster analyses identified seven distinct morphological species of Eurytemora in North America (E. affinis, E. americana, E. canadensis, E. composita, E. herdmani, E. pacifica, and E. raboti), and identified diagnostic characters that distinguish the species (forming the basis for a new identification key). Several previously named species were regarded as synonyms. The sites we sampled in Alaska were remarkable in the high levels of sympatry of Eurytemora species, to a degree not seen outside of Alaska. Future studies of Eurytemora should shed light on patterns of habitat invasions and physiological evolution within the genus, and yield insights into mechanisms leading to its remarkably broad geographic and habitat range.