ABSTRACT

Small red algal morphologically variable blades have been extensively collected from Hawaiian reefs, but for many specimens their taxonomy remains poorly understood. In surveys of the Papahānaumokuākea Marine National Monument (PMNM) and Main Hawaiian Islands (MHI), we discovered two taxa of undescribed small (< 5 cm) red blades that matched the genera Psaromenia and Meredithia, based on morphology and molecular analyses. Neither genus has been previously recorded in the Hawaiian Islands, and neither group of specimens matched currently described species in these two genera. Accordingly, these specimens are described here as new species within the family Kallymeniaceae. Psaromenia laulamaula sp. nov., exclusively found at mesophotic depths (83–94 m) in PMNM, is easily distinguished from other members of the genus by its comparatively large, procarpic carpogonial branch system and solitary obovate pink-to-magenta blades. Conversely, Meredithia hawaiiensis sp. nov., occurring in both shallow (0–17 m) and mesophotic depths (55 m), has high morphological plasticity, with characters that overlap with other Meredithia species, and can only be distinguished based on DNA sequences. This study provides additional evidence of the extent of diversity in the Kallymeniaceae that is poorly characterized from mesophotic depths and provides further evidence that members of the macroalgal flora contain overlooked biodiversity.

摘要

已从夏威夷珊瑚礁广泛收集小型红藻形态可变叶片，但对于许多标本，它们的分类仍然知之甚少。在对 Papahānaumokuākea 海洋国家纪念碑 (PMNM) 和主要夏威夷群岛 (MHI) 的调查中，我们根据形态和分子分析发现了两个与Psaromenia和Meredithia属相匹配的未描述的小 (< 5 cm) 红色叶片分类群。这两个属以前都没有在夏威夷群岛记录过，而且这两组标本都没有与这两个属中目前描述的物种相匹配。因此，这些标本在这里被描述为Kallymeniaceae科的新物种。月桂油棕sp。nov.，仅在 PMNM 的中光深度（83-94 m）中发现，通过其相对较大的前心侧枝系统和孤立的倒卵形粉红色至品红色叶片很容易与该属的其他成员区分开来。相反，Meredithia hawaiiensis sp。nov.，发生在浅层（0-17 m）和中光深度（55 m），具有较高的形态可塑性，具有与其他Meredithia物种重叠的特征，并且只能根据DNA序列进行区分。这项研究为 Kallymeniaceae 的多样性程度提供了额外的证据，从中光深度来看，这种多样性的特征很差，并提供了进一步的证据，证明大型藻类植物群的成员包含被忽视的生物多样性。