A1 Journal article (refereed)
Integrative taxonomy resolves species identities within the Macrobiotus pallarii complex (Eutardigrada: Macrobiotidae) (2021)

Stec, D., Vecchi, M., Dudziak, M., Bartels, P. J., Calhim, S., & Michalczyk, Ł. (2021). Integrative taxonomy resolves species identities within the Macrobiotus pallarii complex (Eutardigrada: Macrobiotidae). Zoological Letters, 7, Article 9. https://doi.org/10.1186/s40851-021-00176-w

JYU authors or editors

Publication details

All authors or editors: Stec, Daniel; Vecchi, Matteo; Dudziak, Magdalena; Bartels, Paul J.; Calhim, Sara; Michalczyk, Łukasz

Journal or series: Zoological Letters

eISSN: 2056-306X

Publication year: 2021

Publication date: 27/05/2021

Volume: 7

Article number: 9

Publisher: Biomed Central

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1186/s40851-021-00176-w

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/76081


The taxonomy of many groups of meiofauna is challenging due to their low number of diagnostic morphological characters and their small body size. Therefore, with the advent of molecular techniques that provide a new source of traits, many cryptic species have started to be discovered. Tardigrades are not an exception, and many once thought to be cosmopolitan taxa are being found to be complexes of phenotypically similar species. Macrobiotus pallarii Maucci, 1954 was originally described in South Italy and has been subsequently recorded in Europe, America, and Asia. This allegedly wide geographic range suggests that multiple species may be hidden under this name. Moreover, recently, genetic evidence to support this was put forward, and the Macrobiotus pallarii complex has been proposed to accommodate putative species related to M. pallarii. Here, we describe three new pseudocryptic species based on populations that would have been all classified as Macrobiotus pallarii if molecular methods were not employed. Using an integrative taxonomy approach, we analyzed animals and eggs from the topotypic population of Macrobiotus pallarii, together with four other populations of the complex. We recovered four distinct phylogenetic lineages that, despite the overlap of morphometric traits, can be separated phenotypically by subtle but discrete morphological characters. One lineage corresponds to Macrobiotus pallarii, whereas the other three are newly described as Macrobiotus margoae Stec, Vecchi & Bartels, sp. nov. from the USA, Macrobiotus ripperi Stec, Vecchi & Michalczyk, sp. nov. from Poland and Finland, and Macrobiotus pseudopallarii Stec, Vecchi & Michalczyk, sp. nov. from Montenegro. To facilitate species identification, we provide a dichotomous key for species of the M. pallarii complex. Delimitation of these pseudocryptic taxa highlights the need for an integrative approach to uncover the phylum’s diversity in full.

Keywords: Tardigrada; systematics; phylogenetics; determination of species; DNA; DNA barcodes

Free keywords: cryptic taxa; DNA barcoding; egg ornamentation; new species; species complex; species delimitation

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Ministry reporting: Yes

Reporting Year: 2021

JUFO rating: 1

Last updated on 2022-20-09 at 14:22