Staghorn or stingray? High-resolution network analysis of cartilaginous trabeculae
Flaum, B.; Schmitt, K.; Hu, R.; Kong, T.F.; Mollen, F.H.; Baum, D.; Debiais-Thibaud, M.; Dean, M. (2025). Staghorn or stingray? High-resolution network analysis of cartilaginous trabeculae, in: SCIB 2025: The Society for Integrative and Comparative Biology Conference, 3-7 January, Atlanta, GA: Abstracts.
In: (2025). SCIB 2025: The Society for Integrative and Comparative Biology Conference, 3-7 January, Atlanta, GA: Abstracts. Society for Integrative and Comparative Biology (SICB): Herndon. , more
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Document type: Summary
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| Authors | | Top |
- Flaum, B.
- Schmitt, K.
- Hu, R.
- Kong, T.F.
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- Mollen, F.H., more
- Baum, D.
- Debiais-Thibaud, M.
- Dean, M.
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| Abstract |
Sharks and rays possess cartilaginous skeletons supported by a cortex of mineralized tiles (tesserae) encasing the unmineralized core, imparting dynamic compressive stiffness to skeletal elements. In certain hard prey-feeding stingrays, an additional reinforcement exists, hollow mineralized trabeculae coursing throughout the unmineralized cartilage like support beams in a building. We combined high-resolution micro-CT imaging and custom quantitative network analyses in a multi-scale characterization of this trabecular network in a series of cownose rays (Rhinoptera). We demonstrate that trabeculae are highly aligned toward the occlusion surface, thickest near their origins, on the non-occlusal side of the jaw, before branching into smaller struts under the teeth. In the labiolingual direction, the trabeculae are considerably more mineralized under the functional teeth, with those under the forming dentition appearing distinctly wispy in microCT. The upright branching morphology of trabeculae gives the network the appearance of colonies of staghorn coral, with the finer branching near the teeth suggesting trabeculae may compartmentalize the unmineralized cartilage in addition to providing compressive reinforcement. Notably, the interaction between trabeculae and the jaw cortex is complex: trabeculae are also formed by individual tesserae but exposed to the external environment via pores in the cortex. The pores suggest a potential growth mechanism for trabeculae through cortical invaginations into unmineralized cartilage, indicating that trabeculae could provide novel models for understanding factors driving cartilage mineralization, growth and mechanics. |
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