ABSTRACT Udotea geppiorum is reported to form meadows in deep-water, soft sediment habitats in the Main Hawaiian Islands. The identification of the species, initially published as U. argentea in the archipelago, is revised and confirmed based on morphological assessment and comparative DNA sequencing with western Pacific specimens. Udotea geppiorum is fully corticated and newly shown to display discrete concentric segments arranged in a ‘tongue and groove’ manner, which are connected by medullary siphons running along the entire segment interface. Udotea geppiorum is phylogenetically nested among a cluster of Udotea spp. recently circumscribed within Udotea sensu stricto. This cluster of species is separate from the remainder of the family Udoteaceae, which includes several genera and Udotea spp. sensu lato that lack or exhibit incomplete cortication. Based on field observations conducted in O‘ahu and Maui, U. geppiorum can be found from 20 m to > 90 m depth with a peak in abundance at mesophotic depths of 60–85 m, where it forms extensive meadows that support associated diversity.

中文翻译：

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夏威夷主要岛屿中光草甸生态观测对 Udotea geppiorum（Bryopsidales，Chlorophyta）的分子确认和形态学重新评估

摘要 据报道，Udotea geppiorum 在夏威夷主群岛的深水软沉积物栖息地形成草甸。该物种的鉴定最初在群岛上以 U. argentea 的名称发表，根据形态学评估和与西太平洋标本的 DNA 比较测序进行了修订和确认。Udota geppiorum 是完全皮质的，新近显示为显示以“舌头和凹槽”方式排列的离散同心节段，这些节段由沿着整个节段界面运行的髓质虹吸管连接。Udotea geppiorum 在系统发育上嵌套在一组 Udotea spp 中。最近被限制在 Udota sensu stricto 之内。这组物种与 Udoteaceae 家族的其余部分分开，后者包括几个属和 Udotea spp。缺乏或表现出不完全皮质的感觉。根据在欧胡岛和毛伊岛进行的实地观察，可以在 20 m 到 > 90 m 的深度范围内发现 U. geppiorum，在 60-85 m 的中光深度处具有丰度峰值，在那里它形成了支持相关多样性的广阔草地。