Hydrodynamic Function of the Slimy and Scaly Surfaces of Teleost Fishes.
| Autor: | Wainwright DK; Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, United States., Lauder GV; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, United States., Gemmell BJ; Department of Integrative Biology, University of South Florida, Tampa, Florida 33620, United States. |
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| Jazyk: | angličtina |
| Zdroj: | Integrative and comparative biology [Integr Comp Biol] 2024 Sep 17; Vol. 64 (2), pp. 480-495. |
| DOI: | 10.1093/icb/icae066 |
| Abstrakt: | The scales and skin mucus of bony fishes are both proposed to have a role in beneficially modifying the hydrodynamics of water flow over the body surface. However, it has been challenging to provide direct experimental evidence that tests how mucus and fish scales change the boundary layer in part due to the difficulties in working with live animal tissue and difficulty directly imaging the boundary layer. In this manuscript, we use direct imaging and flow tracking within the boundary layer to compare boundary layer dynamics over surfaces of fish skin with mucus, without mucus, and a flat control surface. Our direct measurements of boundary layer flows for these three different conditions are repeated for two different species, bluegill sunfish (Lepomis macrochirus) and blue tilapia (Oreochromis aureus). Our goals are to understand if mucus and scales reduce drag, shed light on mechanisms underlying drag reduction, compare these results between species, and evaluate the relative contributions to hydrodynamic function for both mucus and scales. We use our measurements of boundary layer flow to calculate shear stress (proportional to friction drag), and we find that mucus reduces drag overall by reducing the velocity gradient near the skin surface. Both bluegill and tilapia showed similar patterns of surface velocity reduction. We also note that scales alone do not appear to reduce drag, but that mucus may reduce friction drag up to 50% compared to scaled surfaces without mucus or flat controls. (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.) |
| Databáze: | MEDLINE |
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