Abstract:
All eight extant species ofRhabdopleuradescribed between 1869 and 2018 are provisionally accepted as valid based on a review of the literature and new data on two little-known species from the Azores. Additionally, four new species are described from the New Zealand region, increasing global diversity by 50%, and a dichotomous key to all 12 described species is provided based on morphological criteria. The distinction between colony morphologies based on erect-tube inception is regarded as particularly helpful in initial characterization of species. Erect ringed tubes are either produced directly from the surface of creeping-tubes or indirectly, i.e. a short adherent side branch from a creeping tube is interpolated between the creeping tube and an erect tube; such side branches are blind-ending. These two modes of erect-tube origination are here respectively termeddirectandindirect. Species with indirect erect-tube budding are predominant in the North Atlantic whereas species with direct erect-tube budding dominate in New Zealand waters. The only indirect-erect species from New Zealand, Rhabdopleura chathamica n. sp., was discovered on deepwater coral from 10081075 m, constituting the deepest record of the genus to date. Rhabdopleura emancipata n. sp., collected only in a detached state, constitutes a three-dimensional tangled growth that grew freely into the water columna unique morphology hitherto unknown among extant species. Owing to this growth mode, it provided a substratum for epibionts from several phyla. Rhabdopleura francesca n. sp. and Rhabdopleura decipula n. sp. are morphologically very similar but are distinguishable by their distinct placements in a phylogeny based on 16S mitochondrial and 18S nuclear rRNA genes. Phylogenetic reconstructions based on rRNA and mitochondrial genome data contribute to an updated phylogeny of all Rhabdopleura species sequenced thus far, some of which require more molecular sequences and morphological analyses for taxonomic determination.
摘要:
根据对亚速尔群岛两个鲜为人知的物种的文献和新数据的回顾,在1869年至2018年之间描述的所有8种现存的Rhabdopleurad物种都被暂时接受为有效。此外,描述了来自新西兰地区的四个新物种,全球多样性增加50%,并根据形态学标准提供了所有12个描述物种的二分键。基于直立管开始的菌落形态之间的区别被认为对物种的初始表征特别有用。直立环形管可以直接从爬行管的表面生产,也可以间接生产。即,在蠕变管和直立管之间插入了来自蠕变管的短粘附侧分支;这样的侧分支是盲目的。直管起源的这两种模式在这里分别是直接和间接的。在北大西洋,具有间接直立管出芽的物种占主导地位,而在新西兰水域,具有直接直立管出芽的物种占主导地位。新西兰唯一的间接直立物种,Rhabdopleurachathamican.sp.,在10081075米的深水珊瑚上发现,构成该属迄今为止最深的记录。Rhabdopleuraemancipatan.sp.,仅在分离状态下收集,构成了三维缠结的生长,自由地生长到水柱中,这是现存物种迄今未知的独特形态。由于这种增长模式,它为来自几个门的epibionts提供了基础。Rhabdopleurafrancescan.sp.和Rhabdopleuradeculan.sp.在形态上非常相似,但在基于16S线粒体和18S核rRNA基因的系统发育中,它们的不同位置可区分。基于rRNA和线粒体基因组数据的系统发育重建有助于迄今为止测序的所有Rhabdopleura物种的最新系统发育,其中一些需要更多的分子序列和形态学分析来进行分类学测定。