The Experts below are selected from a list of 615 Experts worldwide ranked by ideXlab platform
Stephen Wroe - One of the best experts on this subject based on the ideXlab platform.
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A Novel Method for Single Sample Multi-Axial Nanoindentation of Hydrated Heterogeneous Tissues Based on Testing Great White Shark Jaws
2016Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the Great White Shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this Shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of Great White Shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of Shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity
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a novel method for single sample multi axial nanoindentation of hydrated heterogeneous tissues based on testing Great White Shark jaws
PLOS ONE, 2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the Great White Shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this Shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of Great White Shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of Shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity, such as samples obtained from endangered species or pathological tissues. We also outline a method for tip-to-optic calibration that facilitates nanoindentation of soft biological tissues. Our technique may help address the critical need for a nanomechanical testing method that is applicable to a variety of hydrated biological materials whether soft or hard.
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Optical Images from the Hysitron Triboindenter of mineralized (A, B) and non-mineralized (C, D) Great White Shark jaw cartilage. The image of the anterior surface of mineralized cartilage (A) shows the optical cross hairs (blue) on a block of mineralized cartilage. The image of the ventral surface (B) shows numerous nodules (e.g. White arrow) present in the jaw cartilage. Images C and D are both from the ventral surface of the same sample of cartilage and show differences observed in topology in the non-mineralized layer.
2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Optical Images from the Hysitron Triboindenter of mineralized (A, B) and non-mineralized (C, D) Great White Shark jaw cartilage. The image of the anterior surface of mineralized cartilage (A) shows the optical cross hairs (blue) on a block of mineralized cartilage. The image of the ventral surface (B) shows numerous nodules (e.g. White arrow) present in the jaw cartilage. Images C and D are both from the ventral surface of the same sample of cartilage and show differences observed in topology in the non-mineralized layer.
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Boxplots.
2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Boxplots show variation in Young’s modulus (A) and hardness (B) for mineralized and non-mineralized Great White Shark jaw cartilage in different directions. Axes are in gigapascals (GPa). Whiskers on boxplots represent minimum and maximum values.
Philip Boughton - One of the best experts on this subject based on the ideXlab platform.
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A Novel Method for Single Sample Multi-Axial Nanoindentation of Hydrated Heterogeneous Tissues Based on Testing Great White Shark Jaws
2016Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the Great White Shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this Shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of Great White Shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of Shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity
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a novel method for single sample multi axial nanoindentation of hydrated heterogeneous tissues based on testing Great White Shark jaws
PLOS ONE, 2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the Great White Shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this Shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of Great White Shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of Shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity, such as samples obtained from endangered species or pathological tissues. We also outline a method for tip-to-optic calibration that facilitates nanoindentation of soft biological tissues. Our technique may help address the critical need for a nanomechanical testing method that is applicable to a variety of hydrated biological materials whether soft or hard.
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Optical Images from the Hysitron Triboindenter of mineralized (A, B) and non-mineralized (C, D) Great White Shark jaw cartilage. The image of the anterior surface of mineralized cartilage (A) shows the optical cross hairs (blue) on a block of mineralized cartilage. The image of the ventral surface (B) shows numerous nodules (e.g. White arrow) present in the jaw cartilage. Images C and D are both from the ventral surface of the same sample of cartilage and show differences observed in topology in the non-mineralized layer.
2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Optical Images from the Hysitron Triboindenter of mineralized (A, B) and non-mineralized (C, D) Great White Shark jaw cartilage. The image of the anterior surface of mineralized cartilage (A) shows the optical cross hairs (blue) on a block of mineralized cartilage. The image of the ventral surface (B) shows numerous nodules (e.g. White arrow) present in the jaw cartilage. Images C and D are both from the ventral surface of the same sample of cartilage and show differences observed in topology in the non-mineralized layer.
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Boxplots.
2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Boxplots show variation in Young’s modulus (A) and hardness (B) for mineralized and non-mineralized Great White Shark jaw cartilage in different directions. Axes are in gigapascals (GPa). Whiskers on boxplots represent minimum and maximum values.
Toni L. Ferrara - One of the best experts on this subject based on the ideXlab platform.
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A Novel Method for Single Sample Multi-Axial Nanoindentation of Hydrated Heterogeneous Tissues Based on Testing Great White Shark Jaws
2016Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the Great White Shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this Shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of Great White Shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of Shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity
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a novel method for single sample multi axial nanoindentation of hydrated heterogeneous tissues based on testing Great White Shark jaws
PLOS ONE, 2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the Great White Shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this Shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of Great White Shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of Shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity, such as samples obtained from endangered species or pathological tissues. We also outline a method for tip-to-optic calibration that facilitates nanoindentation of soft biological tissues. Our technique may help address the critical need for a nanomechanical testing method that is applicable to a variety of hydrated biological materials whether soft or hard.
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Optical Images from the Hysitron Triboindenter of mineralized (A, B) and non-mineralized (C, D) Great White Shark jaw cartilage. The image of the anterior surface of mineralized cartilage (A) shows the optical cross hairs (blue) on a block of mineralized cartilage. The image of the ventral surface (B) shows numerous nodules (e.g. White arrow) present in the jaw cartilage. Images C and D are both from the ventral surface of the same sample of cartilage and show differences observed in topology in the non-mineralized layer.
2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Optical Images from the Hysitron Triboindenter of mineralized (A, B) and non-mineralized (C, D) Great White Shark jaw cartilage. The image of the anterior surface of mineralized cartilage (A) shows the optical cross hairs (blue) on a block of mineralized cartilage. The image of the ventral surface (B) shows numerous nodules (e.g. White arrow) present in the jaw cartilage. Images C and D are both from the ventral surface of the same sample of cartilage and show differences observed in topology in the non-mineralized layer.
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Boxplots.
2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Boxplots show variation in Young’s modulus (A) and hardness (B) for mineralized and non-mineralized Great White Shark jaw cartilage in different directions. Axes are in gigapascals (GPa). Whiskers on boxplots represent minimum and maximum values.
Eve Slavich - One of the best experts on this subject based on the ideXlab platform.
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A Novel Method for Single Sample Multi-Axial Nanoindentation of Hydrated Heterogeneous Tissues Based on Testing Great White Shark Jaws
2016Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the Great White Shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this Shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of Great White Shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of Shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity
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a novel method for single sample multi axial nanoindentation of hydrated heterogeneous tissues based on testing Great White Shark jaws
PLOS ONE, 2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the Great White Shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this Shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of Great White Shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of Shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity, such as samples obtained from endangered species or pathological tissues. We also outline a method for tip-to-optic calibration that facilitates nanoindentation of soft biological tissues. Our technique may help address the critical need for a nanomechanical testing method that is applicable to a variety of hydrated biological materials whether soft or hard.
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Optical Images from the Hysitron Triboindenter of mineralized (A, B) and non-mineralized (C, D) Great White Shark jaw cartilage. The image of the anterior surface of mineralized cartilage (A) shows the optical cross hairs (blue) on a block of mineralized cartilage. The image of the ventral surface (B) shows numerous nodules (e.g. White arrow) present in the jaw cartilage. Images C and D are both from the ventral surface of the same sample of cartilage and show differences observed in topology in the non-mineralized layer.
2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Optical Images from the Hysitron Triboindenter of mineralized (A, B) and non-mineralized (C, D) Great White Shark jaw cartilage. The image of the anterior surface of mineralized cartilage (A) shows the optical cross hairs (blue) on a block of mineralized cartilage. The image of the ventral surface (B) shows numerous nodules (e.g. White arrow) present in the jaw cartilage. Images C and D are both from the ventral surface of the same sample of cartilage and show differences observed in topology in the non-mineralized layer.
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Boxplots.
2013Co-Authors: Toni L. Ferrara, Philip Boughton, Eve Slavich, Stephen WroeAbstract:Boxplots show variation in Young’s modulus (A) and hardness (B) for mineralized and non-mineralized Great White Shark jaw cartilage in different directions. Axes are in gigapascals (GPa). Whiskers on boxplots represent minimum and maximum values.
David W. Sims - One of the best experts on this subject based on the ideXlab platform.
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DOI 10.1007/s00227-009-1233-yMETHOD Concordance of genetic and Wn photo identiWcation in the Great White Shark, Carcharodon carcharias, oV Mossel Bay, South Africa
2015Co-Authors: Chrysoula Gubili, Ryan Johnson, Enrico Gennari, Deon Kotze, Mike Meÿer, David W. Sims, Catherine S. Jones, Hermann W. Oosthuizen, Leslie Robert NobleAbstract:Abstract Visual identiWcation of naturally acquired marks has been a popular if subjective method of animal identiWcation and population estimation over the last 40 years. Molecular genetics has also independently devel-oped objective individual marking techniques during the same period. Here, we assess the concordance of individual Great White Shark (Carcharodon carharias) dorsal Wn rec-ognition and identiWcation, using seven microsatellite loci as the independent unbiased arbiter, over a period of 5 years. As a monitoring technique, Wn photographs oVer a very good individual identiWcation key for White Sharks over a relatively short period of time (5 years), matching with genetic data in about 85 % of cases, whilst caution and a continuously updated database is required for animal rec-ognition over a longer period
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levy flight and brownian search patterns of a free ranging predator reflect different prey field characteristics
Journal of Animal Ecology, 2012Co-Authors: David W. Sims, Nicolas E Humphries, Russell W Bradford, Barry D BruceAbstract:1. Search processes play an important role in physical, chemical and biological systems. In animal foraging, the search strategy predators should use to search optimally for prey is an enduring question. Some models demonstrate that when prey is sparsely distributed, an optimal search pattern is a specialised random walk known as a Levy flight, whereas when prey is abundant, simple Brownian motion is sufficiently efficient. These predictions form part of what has been termed the Levy flight foraging hypothesis (LFF) which states that as Levy flights optimise random searches, movements approximated by optimal Levy flights may have naturally evolved in organisms to enhance encounters with targets (e.g. prey) when knowledge of their locations is incomplete. 2. Whether free-ranging predators exhibit the movement patterns predicted in the LFF hypothesis in response to known prey types and distributions, however, has not been determined. We tested this using vertical and horizontal movement data from electronic tagging of an apex predator, the Great White Shark Carcharodon carcharias, across widely differing habitats reflecting different prey types. 3. Individual White Sharks exhibited movement patterns that predicted well the prey types expected under the LFF hypothesis. Shark movements were best approximated by Brownian motion when hunting near abundant, predictable sources of prey (e.g. seal colonies, fish aggregations), whereas movements approximating truncated Levy flights were present when searching for sparsely distributed or potentially difficult-to-detect prey in oceanic or shelf environments, respectively. 4. That movement patterns approximated by truncated Levy flights and Brownian behaviour were present in the predicted prey fields indicates search strategies adopted by White Sharks appear to be the most efficient ones for encountering prey in the habitats where such patterns are observed. This suggests that C. carcharias appears capable of exhibiting search patterns that are approximated as optimal in response to encountered changes in prey type and abundance, and across diverse marine habitats, from the surf zone to the deep ocean. 5. Our results provide some support for the LFF hypothesis. However, it is possible that the observed Levy patterns of White Sharks may not arise from an adaptive behaviour but could be an emergent property arising from simple, straight-line movements between complex (e.g. fractal) distributions of prey. Experimental studies are needed in vertebrates to test for the presence of Levy behaviour patterns in the absence of complex prey distributions.
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Concordance of genetic and fin photo identification in the Great White Shark, Carcharodon carcharias, off Mossel Bay, South Africa
Marine Biology, 2009Co-Authors: Chrysoula Gubili, Ryan Johnson, Enrico Gennari, W. Hermann Oosthuizen, Deon Kotze, Mike Meÿer, David W. Sims, Catherine S. Jones, Leslie Robert NobleAbstract:Visual identification of naturally acquired marks has been a popular if subjective method of animal identification and population estimation over the last 40 years. Molecular genetics has also independently developed objective individual marking techniques during the same period. Here, we assess the concordance of individual Great White Shark ( Carcharodon carharias ) dorsal fin recognition and identification, using seven microsatellite loci as the independent unbiased arbiter, over a period of 5 years. As a monitoring technique, fin photographs offer a very good individual identification key for White Sharks over a relatively short period of time (5 years), matching with genetic data in about 85% of cases, whilst caution and a continuously updated database is required for animal recognition over a longer period.
