DNA Barcoding of Shark Meats Identify Species Composition and CITES-Listed Species from the Markets in Taiwan

Abstract

BackgroundAn increasing awareness of the vulnerability of sharks to exploitation by shark finning has contributed to a growing concern about an unsustainable shark fishery. Taiwan’s fleet has the 4th largest shark catch in the world, accounting for almost 6% of the global figures. Revealing the diversity of sharks consumed by Taiwanese is important in designing conservation plans. However, fins make up less than 5% of the total body weight of a shark, and their bodies are sold as filets in the market, making it difficult or impossible to identify species using morphological traits.MethodsIn the present study, we adopted a DNA barcoding technique using a 391-bp fragment of the mitochondrial cytochrome oxidase I (COI) gene to examine the diversity of shark filets and fins collected from markets and restaurants island-wide in Taiwan.ResultsAmongst the 548 tissue samples collected and sequenced, 20 major clusters were apparent by phylogenetic analyses, each of them containing individuals belonging to the same species (most with more than 95% bootstrap values), corresponding to 20 species of sharks. Additionally, Alopias pelagicus, Carcharhinus falciformis, Isurus oxyrinchus, and Prionace glauca consisted of 80% of the samples we collected, indicating that these species might be heavily consumed in Taiwan. Approximately 5% of the tissue samples used in this study were identified as species listed in CITES Appendix II, including two species of Sphyrna, C. longimanus and Carcharodon carcharias.ConclusionDNA barcoding provides an alternative method for understanding shark species composition when species-specific data is unavailable. Considering the global population decline, stock assessments of Appendix II species and highly consumed species are needed to accomplish the ultimate goal of shark conservation.

Species identification and comparative population genetics of four coastal houndsharks based on novel NGS‐mined microsatellites

“…During processing morphological and meristic criteria which are pivotal to the accurate identification of specimens are lost (Mendonça et al., ; da Silva & Bürgener, ). Several different genetic identification methods have previously been developed to resolve misidentification issues (Blanco, Pérez‐Martín, & Sotelo, ; Naylor et al., ; Ward, Holmes, White, & Last, ) or to reveal captures of threatened shark species (Clarke et al., ; Liu, Chan, Lin, Hu, & Chen, ; Shivji, Chapman, Pikitch, & Raymond, ). These include gel‐based identification methods (Farrell, Clarke, & Mariani, ; Pank, Stanhope, Natanson, Kohler, & Shivji, ), DNA barcoding (using the cytochrome oxidase c subunit I; Ward et al., ), sequenced‐based identification method (using sequences of the cytochrome b ; (Blanco et al., ) or NADH dehydrogenase subunit 2 gene regions (Naylor et al., )), and high‐resolution melting analysis (Morgan et al., ).…”

Shark Finning and the Molecular Identification of Shark Species: Review and Perspectives

“…Methods such as protein electrophoresis [41,[44][45][46], restriction length polymorphisms (RFLPs) [39,42], PCR methods [40,[47][48][49][50][51][52][53], species identification using insertion-deletion regions (indels) [54], and the nucleotide sequencing approaches mainly focused on mitochondrial genes and commonly using the DNA barcoding methodology, such as presented by several studies [55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70]. Pank et al…”

“…Carvalho and Freitas [62] used the barcoding methods on the identification of shark fins from illegal fisheries retained by the Brazilian authorities, and successfully identified the species Prionace glauca, Sphyrna zygaena, and Isurus oxyrinchus. Liu et al [63] analyzed the species composition of shark meat from fish markets in Taiwan, pointing the species Alopias pelagicus, Carcharhinus falciformis, Prionace glauca, and Isurus oxyrinchus as the most prevalent species on the Taiwan fin trade, while some CITES species were also found such as the great white Carcharodon carcharias, the oceanic whitetip shark Carcharhinus longimanus, and two hammerhead sharks Sphyrna zygaena and Sphyrna lewini. Espinoza et al [68] presented the Mexican first efforts to combat the shark fin trade on the Mexican Pacific waters.…”

Molecular species identification and population genetics of chondrichthyans in South Africa: current challenges, priorities and progress

“…Approximately 5% of shark fillets sampled at markets, supermarkets, street vendors and in restaurants in Taiwan were identified as species listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II, including two species of hammerhead Sphyrna spp., oceanic white tip (Carcharhinus longimanus Poey, 1861) and white shark (Carcharodon carcharias Linnaeus, 1758) (Liu et al 2013). A high incidence (55% of all samples tested) of the critically endangered largetooth sawfish (Pristis pristis Linnaeus, 1758) were found in Brazilian fish markets (Melo Palmeira et al 2013) and almost one-third of fish samples tested for species substitution in Italian fish markets included white shark (Filonzi et al 2010).…”