Organisms Diversity & Evolution

, Volume 10, Issue 4, pp 287–296 | Cite as

Using compensatory base change analysis of internal transcribed spacer 2 secondary structures to identify three new species in Paramacrobiotus (Tardigrada)

  • Ralph O. Schill
  • Frank Förster
  • Thomas Dandekar
  • Matthias WolfEmail author
Original ARticle


Species within the tardigrade genus Paramacrobiotus could be distinguished via an analysis of internal transcribed spacer 2 (ITS2) secondary structures. Sequences of P. richtersi and four populations previously treated under provisional names (Paramacrobiotus ‘richtersi group’ 1 to 4) from different continents were determined and annotated, and their secondary structures were predicted. A tree based on a combined sequence-structure alignment was reconstructed by Neighbor-Joining. The topology obtained is consistent with a tree based on a distance matrix of compensatory base changes (CBCs) between all ITS2 sequence-structure pairs in the global multiple alignment. The CBC analysis, together with 18S rDNA sequences, physiological, biochemical and biophysical data identified three species new to science that are morphologically indistinguishable from P. richtersi. These are formally described under the names Paramacrobiotus fairbanksi sp. nov., P. kenianus sp. nov., and P. palaui sp. nov.


ITS2 Compensatory base change Tardigrada Eutardigrada Cryptic species Species identification 



Research was conducted with equipment made available by the project FUNCRYPTA (0313838A, 0313838B), funded by the German Federal Ministry of Education and Research (BMBF). We acknowledge the assistance of Eva Roth and Steffen Hengherr for managing the tardigrade cultures, of Inge Polle in the molecular work, and of Andy Reuner for the morphometric measurements (all University of Stuttgart, Germany). Furthermore, we cordially acknowledge Alexander Keller (University of Würzburg, Germany) for valuable discussions, and Patrick Meister (University of Würzburg, Germany) and Eileen Clegg (Bodega Bay, California, USA) for final proofreading. The palauan tardigrade species could be collected courtesy of the Bureau of Agriculture, Koror, Republic of Palau.

Supplementary material

13127_2010_25_MOESM1_ESM.doc (133 kb)
Supplementary Table 1 (DOC 133 kb)
13127_2010_25_MOESM2_ESM.doc (130 kb)
Supplementary Table 2 (DOC 130 kb)


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Copyright information

© Gesellschaft für Biologische Systematik 2010

Authors and Affiliations

  • Ralph O. Schill
    • 1
  • Frank Förster
    • 2
  • Thomas Dandekar
    • 2
  • Matthias Wolf
    • 2
    Email author
  1. 1.Zoology, Biological InstituteUniversität StuttgartStuttgartGermany
  2. 2.Department of Bioinformatics, BiocenterUniversity of WürzburgWürzburgGermany

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