Relationships between male anadromy and reproductive traits in a sea-run salmonid fish: an evolutionary ecological test

2015 Fiscal Year Final Research Report

• Project/Area Number: 24570036
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Ecology/Environment
• Research Institution: Japan Fisheries Research and Education Agency
• Principal Investigator: TAMATE Tsuyoshi 国立研究開発法人水産総合研究センター, その他部局等, 研究支援職員 (30374200)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 性淘汰 / 性比 / 雄間闘争 / 体サイズ / 二次性徴形質 / 可塑性 / 生活史戦略

Outline of Final Research Achievements

I tested whether adult male body size and expressions of their representative secondary sexual traits (snout length and hump depth) are positively correlated with adult male proportion (an index of the intensity of sexual selection on males) in five Japanese populations of sea-run masu salmon (Oncorhynchus masou) to verify that sexual selection have driven the evolution of these male reproductive traits in actual animals. Although such positive correlations were not found here, an additional analysis indicated that snout length varied between years (but no inter-year variation in body size and hump depth) in two populations with large sample sizes, suggesting a male life history strategy that plastically changes expressions of secondary sexual traits with relatively low contribution to fertilization success (snout length) according to marine growth conditions.

Free Research Field

動物（魚類）生態学