Development of a method for monitoring fish spawning events using environmental DNA

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15578
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 40030:Aquatic bioproduction science-related
• Research Institution: Kyoto University (2021-2022); Yamaguchi University (2020)
• Principal Investigator: Tsuji Satsuki 京都大学, 理学研究科, 特別研究員(PD) (80867656)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 環境DNA / 産卵 / 精子 / マアジ / アユ / 舞鶴湾

Outline of Final Research Achievements

As reproduction is one of the most important life events for macroorganisms, knowledge of reproductive ecology is essential information for maintaining and managing rare species and commercially important aquatic species. In this study, we applied environmental DNA (eDNA) analysis, which has rapidly developed in recent years as a method for assessing aquatic biodiversity, to develop a non-invasive and effective method for detecting fish spawning behaviour simply by sampling water. As a result, we observed a significant increase in eDNA concentration during spawning due to sperm released from males, and the characteristic dynamics of sperm-derived eDNA were revealed. Furthermore, we successfully estimated the timing and location of the spawning of Japanese horse mackerel (Trachurus japonicus) in Maizuru Bay using an eDNA-based spawning survey.

Free Research Field

水域生態学

Academic Significance and Societal Importance of the Research Achievements

本研究により、これまで直接的な捕獲や観察が必須であった魚類の産卵調査において、水を汲むだけで非侵襲的かつ効果的に産卵の発生や規模を推定する手法を新たに提供することができた。また、これまで種多様性を評価する手法として発展してきた環境DNA分析技術において、対象種の行動を検出する手法としての新たな展開を提示し、さらなる技術開発を促進するものとなったと考えられる。