背景:pallenopsispatagonica(Hoek,1881)是一种形态和遗传可变的海蜘蛛物种,其分类学分类具有挑战性。目前,它被认为是一个物种复合体,包括几个遗传谱系,其中许多尚未被正式描述为物种。该物种群的成员出现在巴塔哥尼亚和南极大陆架以及南极亚岛屿周围。这些栖息地受到历史大规模冰川的强烈影响,先前的研究表明,在冰川最大时期,社区仅限于很少的避难所。因此,这些独立避难所中的同种异体物种形成被认为是导致高纬度南半球海洋底栖类群生物多样性高的常见机制。然而,其他机制,如生态物种形成很少被考虑或测试。因此,我们进行了综合形态和遗传研究巴塔哥尼察物种复合体,以i)解决物种多样性使用目标杂交富集方法,以获得多个基因组标记,ii)找到形态特征并分析形态测量以区分物种,和iii)研究导致物种复合体内多个谱系的物种形成过程。
结果:系统基因组结果支持巴氏疟原虫物种复合体中大多数先前报道的谱系,形态学数据表明,几个谱系是具有诊断特征的不同物种。提出了两个谱系作为新物种,P.aulaeturcarumsp.11月。Dömel&Melzer,2019年和P。11月。Dömel,2019年,分别。然而,并非所有谱系都可以在形态上区分,因此可能代表只能用遗传工具鉴定的隐秘物种。Further,135次测量的形态计量学数据显示,物种内部和物种之间存在很大的变异性,而没有明显的自适应性差异支持。
结论:我们使用目标杂交富集方法为巴塔哥尼卡海蜘蛛物种复合体的成员生成了前所未有的分子数据集,我们结合广泛的形态学和形态学分析来研究分类学,该组的系统发育和生物地理学。广泛的数据集使我们能够划定物种边界,在此基础上,我们正式描述了两个新物种。没有发现阳性选择的一致证据,在同种冰川避难所中呈现物种形成,作为最有可能的物种形成模型。
BACKGROUND: Pallenopsis patagonica (Hoek, 1881) is a morphologically and genetically variable sea spider species whose taxonomic classification is challenging. Currently, it is considered as a species complex including several genetic lineages, many of which have not been formally described as species. Members of this species complex occur on the Patagonian and Antarctic continental shelves as well as around sub-Antarctic islands. These habitats have been strongly influenced by historical large-scale glaciations and previous studies suggested that communities were limited to very few refugia during glacial maxima. Therefore, allopatric speciation in these independent refugia is regarded as a common mechanism leading to high biodiversity of marine benthic taxa in the high-latitude Southern Hemisphere. However, other mechanisms such as ecological speciation have rarely been considered or tested. Therefore, we conducted an integrative morphological and genetic
study on the P. patagonica species complex to i) resolve species diversity using a target hybrid enrichment approach to obtain multiple genomic markers, ii) find morphological characters and analyze morphometric measurements to distinguish species, and iii) investigate the speciation processes that led to multiple lineages within the species complex.
RESULTS: Phylogenomic results support most of the previously reported lineages within the P. patagonica species complex and morphological data show that several lineages are distinct species with diagnostic characters. Two lineages are proposed as new species, P. aulaeturcarum sp. nov. Dömel & Melzer, 2019 and P. obstaculumsuperavit sp. nov. Dömel, 2019, respectively. However, not all lineages could be distinguished morphologically and thus likely represent cryptic species that can only be identified with genetic tools. Further, morphometric data of 135 measurements showed a high amount of variability within and between species without clear support of adaptive divergence in sympatry.
CONCLUSIONS: We generated an unprecedented molecular data set for members of the P. patagonica sea spider species complex with a target hybrid enrichment approach, which we combined with extensive morphological and morphometric analyses to investigate the taxonomy, phylogeny and biogeography of this group. The extensive data set enabled us to delineate species boundaries, on the basis of which we formally described two new species. No consistent evidence for positive selection was found, rendering speciation in allopatric glacial refugia as the most likely model of speciation.