Boedeker Christian, O'Kelly Charles J, Star Wim, Leliaert Frederik
School of Biological Sciences, Victoria University of Wellington, Kelburn Parade, Wellington 6140, New ZealandFriday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, Washington 98250, USANetherlands Centre for Biodiversity Naturalis (section NHN), Leiden University, Einsteinweg 2, 2300 RA Leiden, The NetherlandsPhycology Research Group, Biology Department, Ghent University, Krijgslaan 281 S8, 9000 Ghent, Belgium.
J Phycol. 2012 Jun;48(3):808-25. doi: 10.1111/j.1529-8817.2012.01145.x. Epub 2012 May 4.
The Aegagropila clade represents a unique group of cladophoralean green algae occurring mainly in brackish and freshwater environments. The clade is sister to the species-rich and primarily marine Cladophora and Siphonocladus lineages. Phylogenetic analyses of partial LSU and SSU nrDNA sequences reveal four main lineages within the Aegagropila clade, and allow a taxonomic reassessment. One lineage consists of two marine 'Cladophora' species, for which the new genus Pseudocladophora and the new family Pseudocladophoraceae are proposed. For the other lineages, the family name Pithophoraceae is reinstated. Within the Pithophoraceae, the earliest diverging lineage includes Wittrockiella and Cladophorella calcicola, occurring mainly in brackish and subaerial habitats. The two other lineages are restricted to freshwater. One of them shows a strong tendency for epizoism, and consists of Basicladia species and Arnoldiella conchophila. The other lineage includes Aegagropila, Pithophora and a small number of tropical 'Cladophora' species. The latter are transferred to the new genus Aegagropilopsis. Previously, polypyramidal pyrenoids had been suggested to be apomorphous for this clade, but we report the finding of both polypyramidal and bilenticular pyrenoids in members of the Pithophoraceae, and thus show that this character has no diagnostic value.
团集刚毛藻分支代表了一类独特的鞘藻目绿藻，主要出现在咸淡水和淡水环境中。该分支是物种丰富且主要为海洋生境的刚毛藻属和管枝藻属谱系的姐妹群。对部分 LSU 和 SSU nrDNA 序列的系统发育分析揭示了团集刚毛藻分支内的四个主要谱系，并允许进行分类学重新评估。一个谱系由两个海洋“刚毛藻”物种组成，为此提出了新属假刚毛藻属和新科假刚毛藻科。对于其他谱系，恢复了皮丝藻科的科名。在皮丝藻科内，最早分化的谱系包括维氏藻属和钙生拟刚毛藻，主要出现在咸淡水和亚气生境中。另外两个谱系局限于淡水环境。其中一个表现出强烈的附生倾向，由基枝藻属物种和嗜贝阿诺德藻组成。另一个谱系包括团集刚毛藻属、皮丝藻属和少数热带“刚毛藻”物种。后者被转移到新属拟团集刚毛藻属。此前，有人认为多角形淀粉核是该分支的近裔性状，但我们报告在皮丝藻科成员中发现了多角形和双凸透镜形淀粉核，因此表明这一特征没有诊断价值。
