Phylogeny of the asexual lineage Murrayidae (Macrobiotoidea, Eutardigrada) with the description of Paramurrayon gen. nov. and Paramurrayon meieri sp. nov.

IF 1.8 2区生物学 Q3 EVOLUTIONARY BIOLOGY

Invertebrate Systematics Pub Date : 2022-11-28 DOI:10.1071/IS22031

R. Guidetti, I. Giovannini, Valeria Del Papa, T. Ekrem, D. Nelson, L. Rebecchi, M. Cesari

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引用次数: 1

Abstract

ABSTRACT The peculiar family Murrayidae, comprising the genera Murrayon, Dactylobiotus and Macroversum, contains relatively rare species living in hydrophilic and freshwater habitats on all continents, and contains two of the six exclusively freshwater tardigrade genera. This family probably represents an example of the evolution and persistence of an asexual lineage that differentiated into several taxa without sexual reproduction. Analyses of nuclear and mitochondrial genes (18S, 28S, ITS2 and cox1), and the increase of five taxa to the phylogenetic analyses of Murrayidae led us to infer that Murrayon is polyphyletic, being composed of two ‘species groups’ that also find morphological supports: the ‘dianeae group’ characterised by peculiar egg processes (rod-shaped and covered with a cuticular layer), animals with large, evident epicuticular pillars and small claws; and the ‘pullari group’ characterised by conical egg processes, animals with very small epicuticular pillars, and proportionally larger and longer claws. This latter group is a sister group to Dactylobiotus. Murrayon hastatus is the only species within the genus that has an uncertain position with eggs of the ‘dianeae group’ and animals of the ‘pullari group’. We propose the erection of Paramurrayon gen. nov. (for the ‘dianeae group’ of species), the emendation of Murrayon, and new taxonomic keys for both genera. Possible scenarios of the evolution of taxa within Murrayidae are hypothesised based on synapomorphic characters. Paramurrayon meieri sp. nov. from Norway is described with an integrative approach. Photographs of type material of Murrayon stellatus, Murrayon nocentiniae, Murrayon ovoglabellus and Macroversum mirum are shown for the first time, together with descriptions of new characters. Murrayon hibernicus is considered as nomen dubium and Murrayon hyperoncus is transferred to Macrobiotus pending further analyses.

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无性系拟水蛛科(大生物总目，拟水蛛纲)的系统发育及其对拟水蛛gen. nov和拟水蛛meieri sp. nov的描述。

摘要Murrayidae是一个独特的科，由Murreson属、Dactylobiotus属和Macroversum属组成，包含了生活在各大洲亲水和淡水栖息地的相对罕见的物种，并包含了六个纯淡水缓步动物属中的两个。这个家族可能代表了无性谱系的进化和持久性，无性谱系在没有有性繁殖的情况下分化为几个分类群。对细胞核和线粒体基因（18S、28S、ITS2和cox1）的分析，以及Murrayidae系统发育分析中五个分类群的增加，使我们推断Murreson是多系的，由两个“物种群”组成，这两个“种群”也找到了形态学支持：以特殊蛋过程（杆状并覆盖有角质层）为特征的“dianeae群”，有大而明显的表皮柱和小爪子的动物；以及以圆锥形蛋突为特征的“pullari群”，这些动物有非常小的表皮柱，以及按比例更大更长的爪子。后一个类群是Dactylobiotus的姐妹类群。Murreson hastatus是该属中唯一一个与“dianeae group”的卵和“pullari group”的动物有不确定位置的物种。我们建议建立Paramurrayon gen.nov.（用于物种的“dianeae组”），对Murreson进行校正，并为这两个属提供新的分类键。Murrayidae分类群进化的可能场景是基于突触形态特征假设的。采用综合方法对挪威产的梅氏副蘑菇进行了描述。首次展示了星纹Murreson stellatus、夜蛾Murreson nocentniae、卵形Murreson ovaglabellus和大苦艾的打字材料照片，并对新字符进行了描述。hibernicus被认为是nomen dubium，hyperoncus被转移到Macrobitus等待进一步分析。

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来源期刊

Invertebrate Systematics 生物-动物学

CiteScore

4.30

自引率

9.10%

发文量

审稿时长

>12 weeks

期刊介绍： Invertebrate Systematics (formerly known as Invertebrate Taxonomy) is an international journal publishing original and significant contributions on the systematics, phylogeny and biogeography of all invertebrate taxa. Articles in the journal provide comprehensive treatments of clearly defined taxonomic groups, often emphasising their biodiversity patterns and/or biological aspects. The journal also includes contributions on the systematics of selected species that are of particular conservation, economic, medical or veterinary importance. Invertebrate Systematics is a vital resource globally for scientists, students, conservation biologists, environmental consultants and government policy advisors who are interested in terrestrial, freshwater and marine systems. Invertebrate Systematics is published with the endorsement of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian Academy of Science.