Molecular Identification of Commercial Fish Maws by DNA Sequencing of 16S rRNA and Cytochrome c Oxidase I Genes

• Published in: Journal of food protection Vol. 85; no. 10; pp. 1439 - 1445
• Main Authors: Zhang, Jinju, Deng, Qiuting, Liu, Xindan, Wu, Menghua, Ma, Zhiguo, Shaw, Pang-Chui, Zhang, Ying, Cao, Hui
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2022; Elsevier Limited
• Subjects: 16S rRNA gene; Animals; Bats; Clustering; Conservation of Natural Resources; Cytochrome; Cytochrome c oxidase I gene; Cytochrome-c oxidase; Cytochromes; Divergence; DNA sequencing; Electron Transport Complex IV - genetics; Endangered animals; Endangered species; Fish; Fish maw; Fisheries; Fishes; Food; Food resources; Food safety; Gene sequencing; Genes; Homogeneity; Morphology; Overfishing; Oxidase; Perciformes; Phylogenetics; Phylogeny; Physical characteristics; RNA, Ribosomal, 16S - genetics; rRNA 16S; Seafood; Sequence Analysis, DNA; Species extinction; Species identification; Swim bladder; Threatened species; China; Seafood; Cytochrome c oxidase I gene; Fish maw; Species identification; DNA sequencing; 16S rRNA gene
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/JFP-22-121

Fish maws (dried swim bladders) have long been used for medicinal tonics and as a valuable food resource in Southeast Asia. However, it is difficult to identify the original species of fish maws sold in markets due to a lack of taxonomic characteristics. In the present study, 37 kinds of commercial fish maws from various medicinal material markets were examined, and gene sequences were successfully obtained from ca. 95% of the samples. Partial sequences of the 16S rRNA gene and cytochrome coxidase I (COI) gene were obtained and used to investigate the origin of these commercial fish maws. Thirty-five specimens belonged to nine species: five croakers and four noncroakers. All species identification was supported by both high homogeneity (98 to 100%) and clear clustering with low within-group Kimura two-parameter divergence scores (0 to 0.04 for 16S rRNA and 0 to 0.07 for COI) and high between-group divergence scores (0.07 to 0.15 for 16S rRNA and 0.11 to 0.24 for COI). Croakers were the predominant species, accounting for 74% of the total fish maw specimens. The large demand for croakers has put some species at the risk of extinction due to overfishing. As a valuable food, fish maw has progressively become more popular and has been used as a substitute for shark fin. The identification results allowed us to learn more about the fish species available on the fish maw market and provided an indicator for possible control of threatened or endangered fish species. A probable correlation between the molecular characteristics and morphological features of fish maws was also found and could provide both consumers and merchants with an important reference for identifying the origin of fish maws. •Maws from croaker and noncroaker fishes are widely sold on the markets.•Croakers were the predominant species among the successfully identified samples.•The large demand for some croakers had put them at the risk of extinction.•A correlation between molecular and morphological features of fish maws was found.