spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online August 17, 2007
Journal of Experimental Biology 210, 3036-3042 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.008276
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Heethoff, M.
Right arrow Articles by Koerner, L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Heethoff, M.
Right arrow Articles by Koerner, L.

Small but powerful: the oribatid mite Archegozetes longisetosus Aoki (Acari, Oribatida) produces disproportionately high forces

Michael Heethoff* and Lars Koerner

University of Tübingen, Zoological Institute, Department of Evolutionary Biology of Invertebrates, Auf der Morgenstelle 28E, 72076 Tübingen, Germany


Figure 1
View larger version (35K):
[in this window]
[in a new window]

  		Fig. 1. (A) General morphology and muscular configuration of the first left walking leg of Archegozetes longisetosus: 3D image obtained by X-ray microtomography. Setae on legs were removed during image processing. (B,C) Schematic organization of the claw muscles in sagittal (B) and horizontal (C) view. Note that only the apotele acts through both a levator and a depressor muscle; all other visible muscles are flexors. The claw levator muscle is divided into two subcomponents (not shown), each consisting of one bundle. The claw depressor muscle originates in the tibia and consists of two subcomponents, each with three bundles, which join at a single tendon in the tarsus. cl, claw; dcl, depressor of claw; dt, depressor tendon; fta, flexor of tarsus; fti, flexor of tibia; fge, flexor of genu; lcl, levator of claw; lt, levator tendon. Scale bar, 50 µm.

 

Figure 2
View larger version (53K):
[in this window]
[in a new window]

  		Fig. 2. Distal tarsus and apotele of the first left walking leg of Archegozetes longisetosus showing the single claw. (A) SEM micrograph. (B) 3D image (sagittal virtual section) obtained by X-ray microtomography. Arrowheads indicate the insertion sites of the levator and depressor tendons on the apotele. bp, basilar piece; cl, claw; dt, depressor tendon; lt, levator tendon; x, diameter of claw opening; y, height of claw opening. Scale bars, 10 µm.

 

Figure 3
View larger version (84K):
[in this window]
[in a new window]

  		Fig. 3. SEM-micrographs of surface textures. (A) Ra=30 µm particle size, (B) Ra=1 µm particle size, (C) Ra=0.05 µm particle size. The silhouette of the Archegozetes longisetosus claw (setae removed) illustrates the claw size relative to surface texture. Scale bars, 10 µm.

 

Figure 4
View larger version (11K):
[in this window]
[in a new window]

  		Fig. 4. System for measuring holding forces of Archegozetes longisetosus. The test surfaces were fixed horizontally on a stand. The mite was glued to an insect pin and mounted to the strain gage force transducer (FORT25, WPI Inc., USA), which was connected to a micromanipulator. Forces generated by the mites were transferred to the sensor, amplified by the MP100 system (BIOPAC Systems Inc., USA) and recorded with a personal computer and the software AcqKnowledge 3.8.2 (BIOPAC Systems Inc., USA).

 

Figure 5
View larger version (12K):
[in this window]
[in a new window]

  		Fig. 5. System for measuring pulling forces of Archegozetes longisetosus, using an analytical scale (A&D Instruments Ltd., UK). Mites were glued by the notogaster to an insect pin, which was mounted to a piece of modelling clay. Mites were attached to the vertical test surfaces and the scale was set to zero. Changes in masses were recorded with a personal computer and the software RsKey 1.34 (A&D Instruments Ltd., UK). Negative changes corresponded to pulling forces.

 

Figure 6
View larger version (7K):
[in this window]
[in a new window]

  		Fig. 6. Example of continuously recorded forces and repeated measures of the holding capability of Archegozetes longisetosus.

 

Figure 7
View larger version (5K):
[in this window]
[in a new window]

  		Fig. 7. Box-plot of maximum holding forces on different substrates. Substrate roughness (Ra) significantly affects the holding forces. Holding forces increase with increasing Ra (a, b, c: homogeneous groups, Tukey test).

 

Figure 8
View larger version (4K):
[in this window]
[in a new window]

  		Fig. 8. Example of continuously recorded measures of the pulling forces exerted by Archegozetes longisetosus. The maximum attained force is indicated.

 

Figure 9
View larger version (5K):
[in this window]
[in a new window]

  		Fig. 9. Box-plot of maximum pulling forces exerted by Archegozetes longisetosus on different substrates. Substrate roughness (Ra) significantly affects the pulling forces. The pulling forces of the claw increase with increasing Ra (a, b: homogeneous groups, Tukey test).

 




© The Company of Biologists Ltd 2007