Project description:Pacific saury (Cololabis saira) is an important fish in several countries. Notably, the catch of this fish has markedly decreased recently, which might be due to environmental changes, including feeding habitat changes. However, no clear correlation has been observed. Therefore, the physiological basis of Pacific saury in relation to possible environmental factors must be understood. We sequenced the genome of Pacific saury and extracted RNA from nine tissues (brain, eye, gill, anterior/posterior guts, kidney, liver, muscle, and ovary). In 1.09 Gb assembled genome sequences, a total of 26,775 protein-coding genes were predicted, of which 26,241 genes were similar to known genes in a public database. Transcriptome analysis revealed that 24,254 genes were expressed in at least one of the nine tissues, and 7,495 were highly expressed in specific tissues. Based on the similarity of the expression profiles to those of model organisms, the transcriptome obtained was validated to reflect the characteristics of each tissue. Thus, the present genomic and transcriptomic data serve as useful resources for molecular studies on Pacific saury. In particular, we emphasize that the gene expression data, which serve as the tissue expression panel of this species, can be employed in comparative transcriptomics on marine environmental responses.
Project description:Pacific saury is a primarily wild-caught fish in Taiwan and contains high amounts of polyunsaturated fatty acids (PUFAs). Therefore, its consumption is encouraged by Taiwanese government due to its high nutrition values and affordable price. In this study, four products, Minced saury with pork, Minced saury with XO sauce, Crispy dried saury, and Saury roll with roe, were developed. Optimization of the processing and ingredients were determined by a group of expert panelists, then by a large group of regular consumers. Total bacterial count, coliform, Escherichia coli, volatile base nitrogen, water content, and water activity were analyzed for shelf-life stability. In addition, the indexes of oil oxidation such as acid values, peroxide, and thiobarbituric acid were determined for the oil quality of products. Compositions of fatty acids and fragrant compounds were also analyzed. All microbial, physicochemical, and oil oxidation indexes of the products complied with the official regulations and industrial standards of Taiwan. Composition of fragrant compounds closely related with sensory characteristics and PUFAs composition were not degraded by the processing and storage. A new brand name, Hsiung-Chou, and the logo were established and the products were contracted to manufacturers for commercial production.Supplementary informationThe online version contains supplementary material available at 10.1007/s13197-022-05432-1.
Project description:The Pacific saury (Cololabis saira) is one of the most commercially important pelagic fishes in Asia-Pacific countries. The oceanographic environment, especially the Oyashio Current, significantly affects the distribution of Pacific saury, and may lead to variations in their migration route and the formation of fishing grounds in Japanese coastal region and the high seas. In this study, six oceanographic factors, sea surface temperature (SST), sea surface chlorophyll-a concentration (SSC), sea surface salinity (SSS), sea surface height (SSH), mixed layer depth (MLD), and eddy kinetic energy (EKE), were associated with the monthly catch per unit effort 1 (monthly CPUE1, ton/vessel) and the monthly CPUE2 (ton/day) of Pacific saury from Chinese fishing vessels during the optimal fishing periods (September-November) in 2014-2017. The gradient forest analysis showed that the performance of monthly CPUE1 was higher than monthly CPUE2 and SST was the most important oceanographic factor influencing monthly CPUE1, followed by EKE. The generalized additive model indicated that SST, SSH, and EKE negatively affected monthly CPUE1, whereas SSC, SSS, and MLD induced dome-shaped increases in monthly CPUE1. The distributions of fishing locations are likely to form along Offshore Oyashio current and meanders, especially in October and November. Synchronous trends in the relationship between the intrusion area of the Oyashio and relative abundance variation index suggest that an increase in the intrusion area of the Oyashio causes more Pacific saury to migrate to the Japanese coastal region, and vice versa. These findings extend our understanding of the effects of the oceanographic environment on Pacific saury.