Estimation of reproductive investment of Pacific bluefin tuna based on the analyasis of fat and fatty acid

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06197
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40030:Aquatic bioproduction science-related
• Research Institution: Fisheries Research and Education Agency
• Principal Investigator: Hiroshi Ashida 国立研究開発法人水産研究・教育機構, 水産資源研究所(横浜), 主任研究員 (00603862)
• Co-Investigator(Kenkyū-buntansha): 安藤 靖浩 北海道大学, 水産科学研究院, 准教授 (30261340)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: マグロ / 繁殖投資量 / 産卵数 / 脂肪酸 / 脂質

Outline of Final Research Achievements

The spawning grounds of Pacific bluefin tuna (PBF) is assumed to be located in three areas around Japan (i.e., the water around Nansei Islands, Sea of Japan and Kuroshio-Oyashio transition area). This study examined the reproductive investment of Pacific bluefin tuna using the batch fecundity and the total amount of fatty acid per one hydrated oocyte. Estimated batch fecundity and the total amount of fatty acid per one hydrated oocyte were varied by biotic (e.g., condition factor and body size) and abiotic (e.g., water temperature). Reproductive investment of PBF in the Nansei Islands was the largest among three spawning grounds. Estimated reproductive investment was positive correlation with SST and body size.

Free Research Field

水産資源学

Academic Significance and Societal Importance of the Research Achievements

一般的に、魚類の繁殖能力は産みだす卵の数をベースに評価されてきた、本研究では産卵数に加え、卵内の総脂肪酸量を用いて、繁殖投資量を推定して産卵能力を評価したことに学術的意義がある。本研究の成果は、水産上重要種であり、社会的にも関心の高いクロマグロの再生産構造の理解や産卵能力の高い産卵場の特定に供するための有用な知見となる。