Ereskovsky Alexander V, Richter Daniel J, Lavrov Dennis V, Schippers Klaske J, Nichols Scott A
Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale (IMBE), CNRS, IRD, Aix Marseille Université, Avignon Université, Station Marine d'Endoume, Marseille, France.
Department of Embryology, Faculty of Biology, Saint-Petersburg State University, 7/9 Universitetskaya emb., St. Petersburg, Russia.
PLoS One. 2017 Sep 11;12(9):e0183002. doi: 10.1371/journal.pone.0183002. eCollection 2017.
The homoscleromorph sponge Oscarella carmela, first described from central California, USA is shown to represent two superficially similar but both morphologically and phylogenetically distinct species that are co-distributed. We here describe a new species as Oscarella pearsei, sp. nov. and re-describe Oscarella carmela; the original description was based upon material from both species. Further, we correct the identification of published genomic/transcriptomic resources that were originally attributed to O. carmela, and present new Illumina-sequenced transcriptome assemblies for each of these species, and the mitochondrial genome sequence for O. pearsei sp. nov. Using SSU and LSU ribosomal DNA and the mitochondrial genome, we report the phylogenetic relationships of these species relative to other Oscarella species, and find strong support for the placement of O. pearsei sp. nov. in a distinct clade within genus Oscarella defined by the presence of spherulous cells that contain paracrystalline inclusions; O. carmela lacks this cell type. Oscarella pearsei sp. nov and O. carmela can be tentatively distinguished based upon gross morphological differences such as color, surface texture and extent of mucus production, but can be more reliably identified using mitochondrial and nuclear barcode sequencing, ultrastructural characteristics of cells in the mesohyl, and the morphology of the follicle epithelium which surrounds the developing embryo in reproductively active individuals.
最初在美国加利福尼亚中部被描述的同型硬海绵纲海绵动物卡梅拉奥氏海绵（Oscarella carmela），实际上代表了两个表面相似但在形态和系统发育上都不同的共分布物种。我们在此描述一个新物种，命名为皮尔西奥氏海绵（Oscarella pearsei），新种，并重新描述卡梅拉奥氏海绵；最初的描述是基于来自这两个物种的材料。此外，我们纠正了最初归因于卡梅拉奥氏海绵的已发表基因组/转录组资源的鉴定，并为每个物种提供了新的Illumina测序转录组组装，以及皮尔西奥氏海绵新种的线粒体基因组序列。利用小亚基（SSU）和大亚基（LSU）核糖体DNA以及线粒体基因组，我们报告了这些物种相对于其他奥氏海绵物种的系统发育关系，并发现有强有力的证据支持将皮尔西奥氏海绵新种置于奥氏海绵属内一个由含有准晶体内含物的球状细胞所定义的独特分支中；卡梅拉奥氏海绵缺乏这种细胞类型。皮尔西奥氏海绵新种和卡梅拉奥氏海绵可以根据颜色、表面质地和黏液产生程度等总体形态差异初步区分，但使用线粒体和核条形码测序、中胶层细胞的超微结构特征以及生殖活跃个体中围绕发育胚胎的滤泡上皮形态可以更可靠地鉴定。
