Taxonomy of the little‐studied brown algal species Punctaria mageshimensis (Ectocarpales s.l.) was reexamined by molecular phylogeny and morphology. In the genetic analyses of newly collected specimens using plastid rbcL and psaA gene sequences, the specimens morphologically referable to P. mageshimensis were phylogenetically distant from Ectocarpales s.l. and were included in the clade of Spatoglossum (Dictyotales). Morphological reexamination of the type specimen and newly collected specimens confirmed its systematic position in Dictyotales: Branched thallus; cushion‐shaped rhizoidal holdfast occasionally forming secondary holdfast at the bottom of the thallus; many discoidal plastids without pyrenoid per cell; tetrasporangium‐like reproductive structures with dark, homogeneous cell content; occurrence of hair tufts. Genetically P. mageshimensis was most related to a reported sequence of Spatoglossum asperum, but P. mageshimensis was considerably different from S. asperum as well as other known Spatoglossum species in the deep habitat and in having scarcely‐branched lanceolate and considerably thickened thallus. In conclusion, we propose the transfer of P. mageshimensis to Spatoglossum as S. mageshimense comb. nov.

中文翻译：

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Punctaria mageshimensis 的分子系统发育揭示了其作为 S. mageshimense (Dictyotales, Phaeophyceae) 转移到 Spatoglossum 的证据

通过分子系统发育和形态学重新检查了鲜为人知的褐藻物种 Punctaria mageshimensis (Ectocarpales sl) 的分类学。在使用质体 rbcL 和 psaA 基因序列对新收集的标本进行的遗传分析中，在形态学上与 P. mageshimensis 相关的标本在系统发育上与 Ectocarpales sl 相距甚远，并包括在 Spatoglossum (Dictyotales) 的进化枝中。模式标本和新采集标本的形态学复查证实了其在网纹藻目中的系统地位：分枝叶状体；垫状根状茎偶尔在叶状体底部形成次生茎；许多盘状质体每个细胞没有蛋白核；类似四孢子囊的生殖结构，具有深色、均匀的细胞含量；毛簇的发生。遗传P。mageshimensis 与报道的 Spatoglossum asperum 序列最相关，但 P. mageshimensis 与 S. asperum 以及深层栖息地中的其他已知 Spatoglossum 物种有很大不同，并且具有几乎不分枝的披针形和相当厚的叶状体。总之，我们建议将 P. mageshimensis 作为 S. mageshimense 梳子转移到 Spatoglossum。十一月