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Pahl KB, Yurkowski DJ, Wintner SP, Cliff G, Dicken ML, Hussey NE. Determining the appropriate pretreatment procedures and the utility of liver tissue for bulk stable isotope (δ 13 C and δ 15 N) studies in sharks. JOURNAL OF FISH BIOLOGY 2021; 98:829-841. [PMID: 33251592 DOI: 10.1111/jfb.14635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 11/11/2020] [Accepted: 11/27/2020] [Indexed: 06/12/2023]
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 δ13 C and δ15 N values (i.e., result in artificially lower δ13 C and δ15 N 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 δ13 C 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 δ15 N values between lipid-extracted (LE) liver and lipid-extracted/water washed (WW) treatments, however, WW resulted in significant increases in %N, δ13 C 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 δ13 C values corresponded with movement/habitat behaviours for each shark; minor differences in δ13 C values were observed for known regional movements of DUS and RAG (δ13 CDiffs = 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 δ13 C and δ15 N values to examine elasmobranch ecology.
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Affiliation(s)
- K Blue Pahl
- Department of Integrative Biology, University of Windsor, Windsor, Ontario, Canada
| | - David J Yurkowski
- Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada
| | - Sabine P Wintner
- KwaZulu-Natal Sharks Board, Maritime Centre of Excellence, Umhlanga Rocks, Umhlanga, South Africa
- Biomedical Resource Unit, University of KwaZulu-Natal, Durban, South Africa
- College of Agriculture, Engineering and Science, School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Geremy Cliff
- KwaZulu-Natal Sharks Board, Maritime Centre of Excellence, Umhlanga Rocks, Umhlanga, South Africa
- Biomedical Resource Unit, University of KwaZulu-Natal, Durban, South Africa
- College of Agriculture, Engineering and Science, School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Matthew L Dicken
- KwaZulu-Natal Sharks Board, Maritime Centre of Excellence, Umhlanga Rocks, Umhlanga, South Africa
- Department of Development Studies, School of Economics, Development and Tourism, Nelson Mandela University, Port Elizabeth, South Africa
- College of Agriculture, Engineering and Science, School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Nigel E Hussey
- Department of Integrative Biology, University of Windsor, Windsor, Ontario, Canada
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Nos D, Navarro J, Barría C, Solé M. Carboxylesterase activities in chondrichthyans of the western Mediterranean Sea. MARINE POLLUTION BULLETIN 2017; 119:332-335. [PMID: 28438337 DOI: 10.1016/j.marpolbul.2017.04.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 06/07/2023]
Affiliation(s)
- David Nos
- Institut de Ciències del Mar CSIC, Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain.
| | - Joan Navarro
- Institut de Ciències del Mar CSIC, Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain; Estación Biológica de Doñana CSIC, Avenida Américo Vespucio 26, 41092 Sevilla, Spain
| | - Claudio Barría
- Institut de Ciències del Mar CSIC, Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain
| | - Montserrat Solé
- Institut de Ciències del Mar CSIC, Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain
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Arav R, Rimon S. Purification and characterization of acetyl esterase from bull testes. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 916:313-20. [PMID: 3689793 DOI: 10.1016/0167-4838(87)90175-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Acetyl esterase (acetic-ester acetylhydrolase, EC 3.1.1.6) from bull testes was purified 325-fold by ammonium sulphate precipitation, chromatography on DEAE-cellulose, hydroxyapatite and finally, gel filtration on a Sephadex G-200 column. The purified enzyme appeared as a single protein band on native polyacrylamide gel electrophoresis and in isoelectric focusing (pI 5.25). In both methods, the activity coincided with the protein band. A single protein band corresponding to Mr 70,000 was obtained by SDS-polyacrylamide gel electrophoresis. The reported amino-acid composition indicates that the enzyme contains three half-cystine residues, of which only one could be detected, by titration, as a free -SH group. No free amino terminal was detected by dansylation.
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Affiliation(s)
- R Arav
- Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel
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