Mechanical properties of calcified exoskeleton from the neotropical millipede, Nyssodesmus python
| Autor: | Brendan J. Borrell |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Costa Rica
Male Physiology Cuticle media_common.quotation_subject Millipede Arthropod cuticle Anatomy Insect Biology biology.organism_classification Exoskeleton Biomechanical Phenomena Specific strength Flexural strength Insect Science Animals Regression Analysis Polydesmidae Calcium Female Composite material Arthropods media_common |
| Zdroj: | Journal of insect physiology. 50(12) |
| ISSN: | 0022-1910 |
| Popis: | The calcified exoskeleton of millipedes plays a crucial role in resisting large forces developed during burrowing locomotion. I measured morphological and mechanical properties of cuticle from the neotropical forest floor millipede, Nyssodesmus python (Diplopoda: Polydesmidae), which ranges in body mass from 2 to 7 g. Scaling of thickness of the cuticle with respect to body mass followed predictions of geometric similarity. Both fracture strength and Young's modulus increased with body mass in females but not in males. In spite of their smaller size, male millipedes were still stronger, on average, than female millipedes. Mean fracture strength of millipede cuticle was 124 MPa, and Young's modulus was 17 GPa. Both of these values exceed measurements from typical insect cuticle, suggesting that calcium salts may play a role in stiffening and strengthening the millipede exoskeleton. Because of the high density of calcified millipede cuticle (1660 kg/m3), stiffness and strength relative to body weight remain comparable to values for other insect cuticles. These results corroborate a previous hypothesis that absolute not specific strength and stiffness have been selective factors in the evolution of millipede cuticle, and that bulkiness of the exoskeleton has been minimized through the deposition of calcium salts. |
| Databáze: | OpenAIRE |
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