The denticle surface of thresher shark tails: Three‐dimensional structure and comparison to other pelagic species
Abstract Shark skin denticles (scales) are diverse in morphology both among species and across the body of single individuals, although the function of this diversity is poorly understood. The extremely elongate and highly flexible tail of thresher sharks provides an opportunity to characterize grad...
Published in: | Journal of Morphology |
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Online Access: | http://dx.doi.org/10.1002/jmor.21222 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjmor.21222 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmor.21222 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jmor.21222 https://onlinelibrary.wiley.com/doi/am-pdf/10.1002/jmor.21222 |
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crwiley:10.1002/jmor.21222 2024-06-02T08:13:32+00:00 The denticle surface of thresher shark tails: Three‐dimensional structure and comparison to other pelagic species Popp, Meagan White, Connor F. Bernal, Diego Wainwright, Dylan K. Lauder, George V. National Oceanic and Atmospheric Administration National Science Foundation Office of Naval Research 2020 http://dx.doi.org/10.1002/jmor.21222 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjmor.21222 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmor.21222 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jmor.21222 https://onlinelibrary.wiley.com/doi/am-pdf/10.1002/jmor.21222 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#am http://onlinelibrary.wiley.com/termsAndConditions#vor Journal of Morphology volume 281, issue 8, page 938-955 ISSN 0362-2525 1097-4687 journal-article 2020 crwiley https://doi.org/10.1002/jmor.21222 2024-05-03T11:43:43Z Abstract Shark skin denticles (scales) are diverse in morphology both among species and across the body of single individuals, although the function of this diversity is poorly understood. The extremely elongate and highly flexible tail of thresher sharks provides an opportunity to characterize gradients in denticle surface characteristics along the length of the tail and assess correlations between denticle morphology and tail kinematics. We measured denticle morphology on the caudal fin of three mature and two embryo common thresher sharks ( Alopias vulpinus ), and we compared thresher tail denticles to those of eleven other shark species. Using surface profilometry, we quantified 3D‐denticle patterning and texture along the tail of threshers (27 regions in adults, and 16 regions in embryos). We report that tails of thresher embryos have a membrane that covers the denticles and reduces surface roughness. In mature thresher tails, surfaces have an average roughness of 5.6 μm which is smoother than some other pelagic shark species, but similar in roughness to blacktip, porbeagle, and bonnethead shark tails. There is no gradient down the tail in roughness for the middle or trailing edge regions and hence no correlation with kinematic amplitude or inferred magnitude of flow separation along the tail during locomotion. Along the length of the tail there is a leading‐to‐trailing‐edge gradient with larger leading edge denticles that lack ridges (average roughness = 9.6 μm), and smaller trailing edge denticles with 5 ridges (average roughness = 5.7 μm). Thresher shark tails have many missing denticles visible as gaps in the surface, and we present evidence that these denticles are being replaced by new denticles that emerge from the skin below. Article in Journal/Newspaper Porbeagle Wiley Online Library Journal of Morphology 281 8 938 955 |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract Shark skin denticles (scales) are diverse in morphology both among species and across the body of single individuals, although the function of this diversity is poorly understood. The extremely elongate and highly flexible tail of thresher sharks provides an opportunity to characterize gradients in denticle surface characteristics along the length of the tail and assess correlations between denticle morphology and tail kinematics. We measured denticle morphology on the caudal fin of three mature and two embryo common thresher sharks ( Alopias vulpinus ), and we compared thresher tail denticles to those of eleven other shark species. Using surface profilometry, we quantified 3D‐denticle patterning and texture along the tail of threshers (27 regions in adults, and 16 regions in embryos). We report that tails of thresher embryos have a membrane that covers the denticles and reduces surface roughness. In mature thresher tails, surfaces have an average roughness of 5.6 μm which is smoother than some other pelagic shark species, but similar in roughness to blacktip, porbeagle, and bonnethead shark tails. There is no gradient down the tail in roughness for the middle or trailing edge regions and hence no correlation with kinematic amplitude or inferred magnitude of flow separation along the tail during locomotion. Along the length of the tail there is a leading‐to‐trailing‐edge gradient with larger leading edge denticles that lack ridges (average roughness = 9.6 μm), and smaller trailing edge denticles with 5 ridges (average roughness = 5.7 μm). Thresher shark tails have many missing denticles visible as gaps in the surface, and we present evidence that these denticles are being replaced by new denticles that emerge from the skin below. |
author2 |
National Oceanic and Atmospheric Administration National Science Foundation Office of Naval Research |
format |
Article in Journal/Newspaper |
author |
Popp, Meagan White, Connor F. Bernal, Diego Wainwright, Dylan K. Lauder, George V. |
spellingShingle |
Popp, Meagan White, Connor F. Bernal, Diego Wainwright, Dylan K. Lauder, George V. The denticle surface of thresher shark tails: Three‐dimensional structure and comparison to other pelagic species |
author_facet |
Popp, Meagan White, Connor F. Bernal, Diego Wainwright, Dylan K. Lauder, George V. |
author_sort |
Popp, Meagan |
title |
The denticle surface of thresher shark tails: Three‐dimensional structure and comparison to other pelagic species |
title_short |
The denticle surface of thresher shark tails: Three‐dimensional structure and comparison to other pelagic species |
title_full |
The denticle surface of thresher shark tails: Three‐dimensional structure and comparison to other pelagic species |
title_fullStr |
The denticle surface of thresher shark tails: Three‐dimensional structure and comparison to other pelagic species |
title_full_unstemmed |
The denticle surface of thresher shark tails: Three‐dimensional structure and comparison to other pelagic species |
title_sort |
denticle surface of thresher shark tails: three‐dimensional structure and comparison to other pelagic species |
publisher |
Wiley |
publishDate |
2020 |
url |
http://dx.doi.org/10.1002/jmor.21222 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjmor.21222 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmor.21222 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jmor.21222 https://onlinelibrary.wiley.com/doi/am-pdf/10.1002/jmor.21222 |
genre |
Porbeagle |
genre_facet |
Porbeagle |
op_source |
Journal of Morphology volume 281, issue 8, page 938-955 ISSN 0362-2525 1097-4687 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#am http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/jmor.21222 |
container_title |
Journal of Morphology |
container_volume |
281 |
container_issue |
8 |
container_start_page |
938 |
op_container_end_page |
955 |
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1800737071121301504 |