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  1. Article ; Online: An annotated checklist of the chondrichthyans of South Africa.

    Ebert, David A / Wintner, Sabine P / Kyne, Peter M

    Zootaxa

    2021  Volume 4947, Issue 1, Page(s) zootaxa.4947.1.1

    Abstract: An annotated checklist of chondrichthyan fishes (sharks, batoids, and chimaeras) occurring in South African waters is presented. The checklist is the result of decades of research and on-going systematic revisions of the regional fauna. The ... ...

    Abstract An annotated checklist of chondrichthyan fishes (sharks, batoids, and chimaeras) occurring in South African waters is presented. The checklist is the result of decades of research and on-going systematic revisions of the regional fauna. The chondrichthyan fauna of South Africa is one of the richest in the world with 191 species, comprising 50 families and 103 genera. It consists of 30 families, 64 genera, and 111 species of sharks; 17 families, 36 genera, and 72 species of batoids; and, 3 families, 5 genera, and 8 species of chimaeras. The most species-rich shark families are the whaler sharks Carcharhinidae with 20 species followed by the deepwater catsharks Pentanchidae with 13 species. The most species-rich batoid families are the hardnose stakes Rajidae with at least 21 species followed by the stingrays Dasyatidae with 13 species. This monograph represents the first detailed annotated checklist of chondrichthyans from South Africa in over 30 years.
    MeSH term(s) Animals ; Fishes ; Sharks ; Skates, Fish ; South Africa
    Language English
    Publishing date 2021-03-17
    Publishing country New Zealand
    Document type Journal Article
    ISSN 1175-5334
    ISSN (online) 1175-5334
    DOI 10.11646/zootaxa.4947.1.1
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Cold fins, murky waters and the moon: what affects shark catches in the bather-protection program of KwaZulu–Natal, South Africa?

    Wintner, Sabine P / Sven E. Kerwath

    Marine & freshwater research. 2018, v. 69, no. 1

    2018  

    Abstract: The influence of environmental variables on shark catch in the bather-protection program along the eastern coast of South African was investigated for 11 commonly caught species (Carcharhinus limbatus, C. obscurus, C. brachyurus, C. plumbeus, C. ... ...

    Abstract The influence of environmental variables on shark catch in the bather-protection program along the eastern coast of South African was investigated for 11 commonly caught species (Carcharhinus limbatus, C. obscurus, C. brachyurus, C. plumbeus, C. brevipinna, C. leucas, Carcharodon carcharias, Carcharias taurus, Sphyrna lewini, S. zygaena, Galeocerdo cuvier). Data for the period 1986–1994 were analysed using generalised additive models and generalised additive mixed models. The influence of temporal and spatial factors was respectively considered and removed within a standardisation procedure to investigate and predict the influence of lunar cycle, sea-surface temperature (SST) and water visibility on daily catch. The catches of C. taurus and C. brevipinna were significantly affected by all three factors. Catches of all other species were affected by at least one of the three factors, e.g. six were affected by lunar phase, six by SST and seven by water visibility. The results suggested that measurable, predictable relationships exist between environmental conditions and presence and, consequently, catch of shark species in this program. Understanding these relationships could be useful to mitigate against unwanted catch and to further reduce risk for bathers.
    Keywords Carcharhinus limbatus ; Carcharias ; Carcharodon carcharias ; Galeocerdo cuvier ; Sphyrna lewini ; coasts ; environmental factors ; fins ; models ; risk reduction ; sharks ; surface water temperature ; South Africa
    Language English
    Size p. 167-177.
    Publishing place CSIRO Publishing
    Document type Article
    ZDB-ID 1283028-8
    ISSN 1323-1650
    ISSN 1323-1650
    DOI 10.1071/MF17126
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: Determining the appropriate pretreatment procedures and the utility of liver tissue for bulk stable isotope (δ13C and δ15N) studies in sharks

    Pahl, K. Blue / Yurkowski, David J. / Wintner, Sabine P. / Cliff, G. / Dicken, Matthew L. / Hussey, Nigel E.

    Journal of fish biology. 2021 Mar., v. 98, no. 3 p.829-841

    2021  

    Abstract: Stable‐isotope analysis (SIA) provides a valuable tool to address complex questions pertaining to elasmobranch ecology. Liver, a metabolically active, high turnover tissue (~166 days for 95% turnover), has the potential to reveal novel insights into ... ...

    Abstract Stable‐isotope analysis (SIA) provides a valuable tool to address complex questions pertaining to elasmobranch ecology. Liver, a metabolically active, high turnover tissue (~166 days for 95% turnover), has the potential to reveal novel insights into recent feeding/movement behaviours of this diverse group. To date, limited work has used this tissue, but ecological application of SIA in liver requires consideration of tissue preparation techniques given the potential for high concentrations of urea and lipid that could bias δ¹³C and δ¹⁵N values (i.e., result in artificially lower δ¹³C and δ¹⁵N values). Here we investigated the effectiveness of (a) deionized water washing (WW) for urea removal from liver tissue and (b) chloroform‐methanol for extraction of lipids from this lipid rich tissue. We then (a) established C:N thresholds for deriving ecologically relevant liver isotopic values given complications of removing all lipid and (b) undertook a preliminary comparison of δ¹³C values between tissue pairs (muscle and liver) to test if observed isotopic differences correlated with known movement behaviour. Tests were conducted on four large shark species: the dusky (DUS, Carcharhinus obscurus), sand tiger (RAG, Carcharias taurus), scalloped hammerhead (SCA, Sphyrna lewini) and white shark (GRE, Carcharodon carcharias). There was no significant difference in δ¹⁵N values between lipid‐extracted (LE) liver and lipid‐extracted/water washed (WW) treatments, however, WW resulted in significant increases in %N, δ¹³C and %C. Following lipid extraction (repeated three times), some samples were still biased by lipids. Our species‐specific “C:N thresholds” provide a method to derive ecologically viable isotope data given the complexities of this lipid rich tissue (C:N thresholds of 4.0, 3.6, 4.7 and 3.9 for DUS, RAG, SCA and GRE liverLEWW tissue, respectively). The preliminary comparison of C:N threshold corrected liver and muscle δ¹³C values corresponded with movement/habitat behaviours for each shark; minor differences in δ¹³C values were observed for known regional movements of DUS and RAG (δ¹³CDᵢffₛ = 0.24 ± 0.99‰ and 0.57 ± 0.38‰, respectively), while SCA and GRE showed greater differences (1.24 ± 0.63‰ and 1.08 ± 0.71‰, respectively) correlated to large‐scale movements between temperate/tropical and pelagic/coastal environments. These data provide an approach for the successful application of liver δ¹³C and δ¹⁵N values to examine elasmobranch ecology.
    Keywords Carcharhinus ; Carcharias taurus ; Carcharodon carcharias ; Sphyrna lewini ; habitats ; lipids ; liver ; muscles ; sharks ; stable isotopes ; urea
    Language English
    Dates of publication 2021-03
    Size p. 829-841.
    Publishing place Blackwell Publishing Ltd
    Document type Article ; Online
    Note JOURNAL ARTICLE
    ZDB-ID 410564-3
    ISSN 1095-8649 ; 0022-1112
    ISSN (online) 1095-8649
    ISSN 0022-1112
    DOI 10.1111/jfb.14635
    Database NAL-Catalogue (AGRICOLA)

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  4. Article ; Online: Molecular Taxonomy of South Africa’s Catsharks: How Far Have We Come?

    van Staden, Michaela / Ebert, David A. / Gennari, Enrico / Leslie, Rob W. / McCord, Meaghen E. / Parkinson, Matthew / Watson, Ralph G. A. / Wintner, Sabine / da Silva, Charlene / Bester-van der Merwe, Aletta E.

    Diversity. 2023 July 01, v. 15, no. 7

    2023  

    Abstract: The ability to correctly identify specimens at the species level is crucial for assessing and conserving biodiversity. Despite this, species-specific data are lacking for many of South Africa’s catsharks due to a high level of morphological stasis. As ... ...

    Abstract The ability to correctly identify specimens at the species level is crucial for assessing and conserving biodiversity. Despite this, species-specific data are lacking for many of South Africa’s catsharks due to a high level of morphological stasis. As comprehensive and curated DNA reference libraries are required for the reliable identification of specimens from morphologically similar species, this study reviewed and contributed to the availability of cytochrome c oxidase subunit I (COI) and nicotinamide adenine dehydrogenase subunit 2 (NADH2) sequences for South Africa’s catsharks. A molecular taxonomic approach, implementing species delimitation and specimen assignment methods, was used to assess and highlight any taxonomic uncertainties and/or errors in public databases. The investigated species were summarised into 47 molecular operational taxonomic units (MOTUs), with some conflicting specimen assignments. Two Apristurus specimens sampled in this study remained unidentified, revealing the presence of previously undocumented genetic diversity. In contrast, haplotype sharing within Haploblepharus—attributed to nucleotide ambiguities—resulted in the delimitation of three congeners into a single MOTU. This study reveals that molecular taxonomy has the potential to flag undocumented species and/or misidentified specimens, and further highlights the need to implement integrated taxonomic assessments on catsharks that represent an irreplaceable component of biodiversity in the region.
    Keywords Apristurus ; DNA ; adenine ; biodiversity ; genetic variation ; haplotypes ; molecular systematics ; nicotinamide ; oxidoreductases ; South Africa
    Language English
    Dates of publication 2023-0701
    Publishing place Multidisciplinary Digital Publishing Institute
    Document type Article ; Online
    ZDB-ID 2518137-3
    ISSN 1424-2818
    ISSN 1424-2818
    DOI 10.3390/d15070828
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: Are you really what you eat? Stomach content analysis and stable isotope ratios do not uniformly estimate dietary niche characteristics in three marine predators

    Petta, Julia C. / Shipley, Oliver N. / Wintner, Sabine P. / Cliff, G. / Dicken, Matt L. / Hussey, Nigel E.

    Oecologia. 2020 Apr., v. 192, no. 4 p.1111-1126

    2020  

    Abstract: Calculation of dietary niche characteristics using stable isotopes has become a popular approach to understand the functional role of taxa across food webs. An underlying assumption of this approach is that stable isotopes accurately reflect the dietary ... ...

    Abstract Calculation of dietary niche characteristics using stable isotopes has become a popular approach to understand the functional role of taxa across food webs. An underlying assumption of this approach is that stable isotopes accurately reflect the dietary breadth of a species over a temporal duration defined by tissue-specific isotopic turnover rates. In theory, dietary niche estimates derived from fast turnover rate tissues (e.g., blood plasma and liver) may augment stomach content-derived estimates more agreeably than slower turnover rate tissues (e.g., muscle or fin). We tested this hypothesis by comparing commonly used dietary niche estimates derived from stomach contents (nicheSCA: Levins’, Shannon–Wiener’s, and Smith’s), with those estimated using stable isotopes [nicheSIA: standard ellipse area (SEA), convex hull total area (TA), theta (θ), and ellipse eccentricity (E)] of liver and muscle tissue. Model species were three large-bodied sharks: white (Carcharodon carcharias), dusky (Carcharhinus obscurus), and scalloped hammerhead (Sphyrna lewini). Within-technique comparisons for nicheSCA and nicheSIA metrics (i.e., SEA vs. TA) were often correlated; however, we did not observe any statistically significant correlations between nicheSCA and liver/muscle tissue nicheSIA (i.e., Levins’ vs. SEA). We conclude that nicheSCA and nicheSIA do not provide comparable estimates of dietary niche, at least for the three predator species examined. This fundamental discrepancy highlights technique-specific limitations to estimating organismal dietary niche and identifies a need for the use of clearly defined niche metrics, i.e., the standardized use and reporting of the term isotopic niche as proposed by Newsome et al. (Front Ecol Environ 5:429–436, 2007). Finally, further investigation into the factors underpinning nicheSIA is required to better contextualize this popular ecological metric when compared to nicheSCA.
    Keywords Carcharhinus ; Carcharodon carcharias ; Sphyrna lewini ; blood plasma ; liver ; muscle tissues ; muscles ; stable isotopes ; stomach
    Language English
    Dates of publication 2020-04
    Size p. 1111-1126.
    Publishing place Springer Berlin Heidelberg
    Document type Article ; Online
    Note NAL-AP-2-clean
    ZDB-ID 123369-5
    ISSN 1432-1939 ; 0029-8549
    ISSN (online) 1432-1939
    ISSN 0029-8549
    DOI 10.1007/s00442-020-04628-6
    Database NAL-Catalogue (AGRICOLA)

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  6. Article: Life history of Mustelus mustelus in the Langebaan Lagoon marine protected area

    da Silva, Charlene / Attwood, Colin G. / Wintner, Sabine P. / Wilke, Chris G. / Winker, Henning / Smale, Malcolm J. / Kerwath, Sven E.

    Marine & freshwater research. 2021, v. 72, no. 8

    2021  

    Abstract: Mustelus mustelus from the Langebaan Marine Protected Area (LMPA) has been largely protected from fishing activities for the past 30 years; therefore, its biology represents those of an unfished stock. The reproductive biology, diet, growth and maturity ... ...

    Abstract Mustelus mustelus from the Langebaan Marine Protected Area (LMPA) has been largely protected from fishing activities for the past 30 years; therefore, its biology represents those of an unfished stock. The reproductive biology, diet, growth and maturity of M. mustelus was studied in the Langebaan Lagoon region in the south-western Cape Coast of South Africa between 2007 and 2009. In total, 217 sharks (females: 381–1734mm total length (TL); males: 467–1267mm TL) were examined. Sharks in the Bay represented the largest specimens among six regions, globally. Female parturition, ovulating and mating occurred between November and December after a gestation period of 10–11 months. No ontogenetic shift in diet was evident, with the diet predominantly consisting of the following three species of crustaceans; Hymenosoma orbiculare, Upogebia africana and Callichirus kraussi. The von Bertalanffy growth parameters for combined sexes were L∞=1594mm TL, k=0.15 year-1, t0=–2.01 year (n=95). Possible age over-estimation was investigated using micro-computed tomography, which highlighted the existence of false check marks. This study indicated that the LMPA represents a pupping, nursery and feeding ground as well as a refuge area for the largest and oldest recorded smoothhound sharks globally, emphasising its importance in spatial conservation of this species.
    Keywords Mustelus mustelus ; coasts ; diet ; females ; freshwater ; gestation period ; life history ; marine protected areas ; micro-computed tomography ; ontogeny ; parturition ; refuge habitats ; research ; South Africa
    Language English
    Size p. 1142-1159.
    Publishing place CSIRO Publishing
    Document type Article
    ZDB-ID 1283028-8
    ISSN 1323-1650
    ISSN 1323-1650
    DOI 10.1071/MF20277
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  7. Article ; Online: Comparative population genomics of manta rays has global implications for management.

    Humble, Emily / Hosegood, Jane / Carvalho, Gary / de Bruyn, Mark / Creer, Simon / Stevens, Guy M W / Armstrong, Amelia / Bonfil, Ramon / Deakos, Mark / Fernando, Daniel / Froman, Niv / Peel, Lauren R / Pollett, Stephen / Ponzo, Alessandro / Stewart, Joshua D / Wintner, Sabine / Ogden, Rob

    Molecular ecology

    2023  

    Abstract: Understanding population connectivity and genetic diversity is of fundamental importance to conservation. However, in globally threatened marine megafauna, challenges remain due to their elusive nature and wide-ranging distributions. As overexploitation ... ...

    Abstract Understanding population connectivity and genetic diversity is of fundamental importance to conservation. However, in globally threatened marine megafauna, challenges remain due to their elusive nature and wide-ranging distributions. As overexploitation continues to threaten biodiversity across the globe, such knowledge gaps compromise both the suitability and effectiveness of management actions. Here, we use a comparative framework to investigate genetic differentiation and diversity of manta rays, one of the most iconic yet vulnerable groups of elasmobranchs on the planet. Despite their recent divergence, we show how oceanic manta rays (Mobula birostris) display significantly higher heterozygosity than reef manta rays (Mobula alfredi) and that M. birostris populations display higher connectivity worldwide. Through inferring modes of colonization, we reveal how both contemporary and historical forces have likely influenced these patterns, with important implications for population management. Our findings highlight the potential for fisheries to disrupt population dynamics at both local and global scales and therefore have direct relevance for international conservation of marine species.
    Language English
    Publishing date 2023-11-23
    Publishing country England
    Document type Journal Article
    ZDB-ID 1126687-9
    ISSN 1365-294X ; 0962-1083
    ISSN (online) 1365-294X
    ISSN 0962-1083
    DOI 10.1111/mec.17220
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Determining the appropriate pretreatment procedures and the utility of liver tissue for bulk stable isotope (δ

    Pahl, K Blue / Yurkowski, David J / Wintner, Sabine P / Cliff, Geremy / Dicken, Matthew L / Hussey, Nigel E

    Journal of fish biology

    2020  Volume 98, Issue 3, Page(s) 829–841

    Abstract: Stable-isotope analysis (SIA) provides a valuable tool to address complex questions pertaining to elasmobranch ecology. Liver, a metabolically active, high turnover tissue (~166 days for 95% turnover), has the potential to reveal novel insights into ... ...

    Abstract Stable-isotope analysis (SIA) provides a valuable tool to address complex questions pertaining to elasmobranch ecology. Liver, a metabolically active, high turnover tissue (~166 days for 95% turnover), has the potential to reveal novel insights into recent feeding/movement behaviours of this diverse group. To date, limited work has used this tissue, but ecological application of SIA in liver requires consideration of tissue preparation techniques given the potential for high concentrations of urea and lipid that could bias δ
    MeSH term(s) Animals ; Carbon Isotopes/analysis ; Chemistry Techniques, Analytical/veterinary ; Ecosystem ; Feeding Behavior/physiology ; Lipids/chemistry ; Liver/chemistry ; Muscles/chemistry ; Nitrogen Isotopes/analysis ; Sharks/metabolism ; Species Specificity
    Chemical Substances Carbon Isotopes ; Lipids ; Nitrogen Isotopes
    Language English
    Publishing date 2020-12-28
    Publishing country England
    Document type Journal Article
    ZDB-ID 410564-3
    ISSN 1095-8649 ; 0022-1112
    ISSN (online) 1095-8649
    ISSN 0022-1112
    DOI 10.1111/jfb.14635
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Are you really what you eat? Stomach content analysis and stable isotope ratios do not uniformly estimate dietary niche characteristics in three marine predators.

    Petta, Julia C / Shipley, Oliver N / Wintner, Sabine P / Cliff, Geremy / Dicken, Matt L / Hussey, Nigel E

    Oecologia

    2020  Volume 192, Issue 4, Page(s) 1111–1126

    Abstract: Calculation of dietary niche characteristics using stable isotopes has become a popular approach to understand the functional role of taxa across food webs. An underlying assumption of this approach is that stable isotopes accurately reflect the dietary ... ...

    Abstract Calculation of dietary niche characteristics using stable isotopes has become a popular approach to understand the functional role of taxa across food webs. An underlying assumption of this approach is that stable isotopes accurately reflect the dietary breadth of a species over a temporal duration defined by tissue-specific isotopic turnover rates. In theory, dietary niche estimates derived from fast turnover rate tissues (e.g., blood plasma and liver) may augment stomach content-derived estimates more agreeably than slower turnover rate tissues (e.g., muscle or fin). We tested this hypothesis by comparing commonly used dietary niche estimates derived from stomach contents (niche
    MeSH term(s) Animals ; Carbon Isotopes ; Food Chain ; Gastrointestinal Contents ; Nitrogen Isotopes ; Sharks
    Chemical Substances Carbon Isotopes ; Nitrogen Isotopes
    Language English
    Publishing date 2020-03-16
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 123369-5
    ISSN 1432-1939 ; 0029-8549
    ISSN (online) 1432-1939
    ISSN 0029-8549
    DOI 10.1007/s00442-020-04628-6
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: A new minibarcode assay to facilitate species identification from processed, degraded or historic ray (batoidea) samples

    Wannell, Gregory J / Griffiths, Andrew M / Spinou, Anastasia / Batista, Romina / Mendonça, Marina Barreira / Wosiacki, Wolmar Benjamin / Fraser, Bonnie / Wintner, Sabine / Papadopoulos, Athanasios I / Krey, Grigorios / Gubili, Chrysoula

    Conservation genetics resources. 2020 Dec., v. 12, no. 4

    2020  

    Abstract: Rays (Batoidea) are among the most threatened groups of vertebrates. Slow growth and low fecundity make many species vulnerable to overfishing, but increased demand for gill rakers in traditional Chinese medicine and elasmobranch meat means exploitation ... ...

    Abstract Rays (Batoidea) are among the most threatened groups of vertebrates. Slow growth and low fecundity make many species vulnerable to overfishing, but increased demand for gill rakers in traditional Chinese medicine and elasmobranch meat means exploitation continues. In response, protection has increased, with manta and devilrays (Mobulidae) and sawfishes (Pristidae) now listed on Convention on International Trade in Endangered Species (CITES). This protection requires an accurate assay for species identification, even when parts of the body have been removed or products have been processed. Therefore, we developed and tested a new COI minibarcode to identify ray species among processed samples. This assay was tested on 25 samples from across four batoid orders and showed consistent amplification. In 68% of cases, a correct top match was identified on GenBank and BOLD, but its accuracy should be much higher (particularly due to extensive taxonomic revisions in this group). Bioinformatic analysis of existing sequences also showed 81% of minibarcodes were matched back to a single species and 100% correctly back to all other taxonomic ranks. This increased to 91% when only including records published in the previous 2 years (that should help to account for recent taxonomic revisions). Analysis of skate ‘wings’ and cooked samples was highly successful, allowing the unambiguous identification of species. These results suggest this minibarcode will be highly useful in identifying ray species and could have a range of applications from the analysis of processed products to investigations of environmental DNA, making them an effective tool in the conservation of endangered batoids.
    Keywords Convention on International Trade in Endangered Species ; Manta ; Mobulidae ; Oriental traditional medicine ; Pristidae ; bioinformatics ; environmental DNA ; fecundity ; meat ; overfishing ; species identification ; taxonomic revisions ; vertebrates
    Language English
    Dates of publication 2020-12
    Size p. 659-668.
    Publishing place Springer Netherlands
    Document type Article
    ZDB-ID 2508018-0
    ISSN 1877-7260 ; 1877-7252
    ISSN (online) 1877-7260
    ISSN 1877-7252
    DOI 10.1007/s12686-020-01158-4
    Database NAL-Catalogue (AGRICOLA)

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