University of Miami, Cox Science Center, Miami, FL 33146, USA.
Mol Phylogenet Evol. 2013 Apr;67(1):28-37. doi: 10.1016/j.ympev.2012.12.021. Epub 2013 Jan 11.
Within the crustaceans, the Amphipoda rank as one of the most speciose extant orders. Amphipods have successfully invaded and become major constituents of a variety of ecosystems. The hyperiid amphipods are classically defined as an exclusively pelagic group broadly inhabiting oceanic midwater environments and often having close associations with gelatinous zooplankton. As with other amphipod groups they have largely been classified based on appendage structures, however evidence suggests that at least some of these characters are the product of convergent evolution. Here we present the first multi-locus molecular phylogenetic assessment of relationships among the hyperiid amphipods. We sampled 51 species belonging to 16 of the 23 recognized hyperiidian families for three nuclear loci (18S, 28S, and H3) and mitochondrial COI. We performed both Bayesian Inference and Maximum Likelihood analyses of concatenated sequences. In addition, we also explored the utility of species-tree methods for reconstructing deep evolutionary histories using the Minimize Deep Coalescence (MDC) approach. Our results are compared with previous molecular analyses and traditional systematic groupings. We discuss these results within the context of adaptations correlated with the pelagic life history of hyperiid amphipods. Within the infraorder Physocephalata (Bowman and Gruner, 1973) we inferred support for three reciprocally monophyletic clades; the Platysceloidea, Vibilioidea, and Phronimoidea. Our results also place the enigmatic Cystisomatidae and Paraphronimidae at the base of the infraorder Physosomata (Bowman and Gruner, 1973) suggesting that Physosomata as traditionally recognized is paraphyletic. Based on our multilocus phylogeny, major rearrangements to existing taxonomic groupings of hyperiid amphipods are warranted.
在甲壳动物中，端足目是现存物种最丰富的目之一。端足目成功地入侵并成为各种生态系统的主要组成部分。长尾目端足目动物通常被定义为一个专门的浮游群体，广泛栖息在海洋中层水域，并且经常与凝胶状浮游动物密切相关。与其他端足目动物一样，它们主要是基于附肢结构进行分类的，然而有证据表明，至少其中一些特征是趋同进化的产物。在这里，我们首次对长尾目端足目动物的亲缘关系进行了多基因座分子系统发育评估。我们对 23 个已识别的长尾目科中的 16 个科的 51 种进行了采样，用于三个核基因座（18S、28S 和 H3）和线粒体 COI。我们分别进行了贝叶斯推断和最大似然分析。此外，我们还使用最小化深合并（MDC）方法探索了使用物种树方法重建深层进化历史的效用。我们的结果与以前的分子分析和传统的系统分组进行了比较。我们在与长尾目端足目动物的浮游生活史相关的适应的背景下讨论了这些结果。在亚目 Physocephalata（Bowman 和 Gruner，1973 年）内，我们推断支持三个互为单系的分支；Platysceloidea、Vibilioidea 和 Phronimoidea。我们的结果还将神秘的 Cystisomatidae 和 Paraphronimidae 置于亚目 Physosomata（Bowman 和 Gruner，1973 年）的底部，表明传统上被认可的 Physosomata 是并系的。基于我们的多基因座系统发育，有必要对长尾目端足目动物的现有分类群进行重大调整。
