A morphological comparison of two closely related ptychoid oribatid mite species: Phthiracarus longulus and P. globosus (Acari: Oribatida: Phthiracaroidea)

Authors

  • Sebastian Schmelzle Universität Tübingen
  • Roy A. Norton State University of New York
  • Michael Heethoff Universität Tübingen

Keywords:

Synchrotron X-ray microtomography, SR-µCT, Ptychoidy, Phthiracaridae, Box mite, Predator defence

Abstract

We studied exoskeletal and muscular adaptations to ptychoidy in the oribatid mite Phthiracarus globosus (Phthiracaridae, Phthiracaroidea) using synchrotron X-ray microtomography, and compared the results to Phthiracarus longulus, a closely related mite that we investigated earlier. As expected, both species show high similarity in most of the characters investigated, but there were also clear differences: the sensillus groove is more prominent and the bothridial scale is more angular in P. globosus than in P. longulus. The coxisternal retractor first found in P. longulus was also found in P. globosus and therefore could be a synapomorphy for the genus. The number of muscle fibres of the anterior dorsal endosternal muscle (ade), inferior prodorsal retractor (ipr), ventral plate adductor (vpa) and the notogaster lateral compressor (nlc) found in P. globosus is double or even triple that found in P. longulus. Our results suggest that muscle morphology might provide a phylogenetically informative set of characters for oribatid mite systematics, when more data are available.

References

Betz, O., U. Wegst, D. Weide, M. Heethoff, L. Helfen, W. K. Lee & P. Cloetens (2007): Imaging applications of synchrotron x-ray micro-tomography in biological morphology and biomaterial science. I. General aspects of the technique and its advantages in the analysis of arthropod structure.– Journal of Microscopy 22: 51–71.

Heethoff, M. & P. Cloetens (2008): A comparison of synchrotron X-ray phase contrast tomography and holotomography for non-invasive investigations of the internal anatomy of mites. – Soil Organisms 80 (2): 205–215.

Heethoff, M., L. Helfen & P. Cloetens (2008): Non-invasive 3D-visualization of the internal organization of microarthropods using synchrotron X-ray-tomography with sub-micron resolution. – Journal of Visualized Experiments 15: e737, DOI: 10.3791/737.

Niedbała, W. (2002): Ptyctimous mites (Acari, Oribatida) of the Nearctic Region. – Monographs of the Upper Silesian Museum, Bytom 4: 1–261.

Sanders, F. H. & R. A. Norton (2004): Anatomy and function of the ptychoid defensive mechanism in the mite Euphthiracarus cooki (Acari: Oribatida). – Journal of Morphology 259: 119–154.

Schmelzle, S., L. Helfen, R. A. Norton & M. Heethoff (2008): The ptychoid defensive mechanism in Euphthiracaroidea (Acari: Oribatida): A comparison of exoskeletal elements. – Soil Organisms 80 (2): 227–241.

Schmelzle, S., L. Helfen, R. A. Norton & M. Heethoff (2009): The ptychoid defensive mechanism in Euphthiracaroidea (Acari: Oribatida): A comparison of muscular elements with functional considerations. – Arthropod Structure and Development 38 (6): 461–472.

Schmelzle, S., L. Helfen, R. A. Norton & M. Heethoff (2010): The ptychoid defensive mechanism in Phthiracarus longulus (Acari, Oribatida, Phthiracaroidea): Exoskeletal and muscular elements. – Soil Organisms 82 (2): 253–273.

Weigmann, G. (2006): Hornmilben (Oribatida). – Goecke & Evers, Keltern: 520 pp.

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Published

2012-08-01

How to Cite

Schmelzle, S., Norton, R. A., & Heethoff , M. (2012). A morphological comparison of two closely related ptychoid oribatid mite species: Phthiracarus longulus and P. globosus (Acari: Oribatida: Phthiracaroidea). SOIL ORGANISMS, 84(2), 431–443. Retrieved from https://soil-organisms.org/index.php/SO/article/view/274

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