2003 Fiscal Year Annual Research Report

魚類群集における反対称捕食の維持機構の数理生態学的研究

Research Project

Project/Area Number	15570014
Research Institution	The University of Tokyo
Principal Investigator	松田裕之東京大学, 海洋研究所, 助教授 (70190478)
Co-Investigator(Kenkyū-buntansha)	勝川俊雄東京大学, 海洋研究所, 助手 (90302679) 堀道雄京都大学, 大学院・理学研究科, 教授 (40112552)
Keywords	分断非対称性 / 交差捕食 / 魚類 / 数理モデル / 周期変動 / 雑食
Research Abstract	いくつかの魚類において,体が右か左に曲がる二型があることが報告され,これが分断非対称性の例とみなされ始めている.この左右二型は遺伝子,各種における右利きの頻度は0.5を中心に周期変動し,右利きの捕食者はおもに左利きの被食者を食べ,左利きの捕食者は右利きの被食者を食べる(交差捕食)ことが報告されている.われわれはこの交差捕食が左右二型の維持に有効な頻度依存淘汰をもたらす(右利きの捕食者が少数派になったとき,左利きの捕食者は被食圧が低く頻度が増え,結果的に右利きの捕食者が有利になる)と考え,捕食者と被食者の左右性を同寺院考えた数理モデルを解析した.その結果,被食者と捕食者の2種からなる左右二型の頻度変化は,たいへんゆっくりとではあるが,左右半々の定常点に漸近する.しかし,3栄養段階系を考え,最上位捕食者が中位も下位も捕食する雑食者の場合,3者は永久に振動し続けるリミットサイクルが現れることを数理モデルの安定性解析,存続可能性解析により見出した. それに対して,右利きの捕食者が右利きの被食者をより多く食べる(平行捕食の)雑食者がいる3種系の数理モデルでは,左右二型は維持されず,どちらか一方のみが存続するか,3栄養段階のうち中位もしくは上位捕食者が絶滅することが理論的に示された. 本研究の成果をAmericanNaturalist誌に投稿し,先日受理通知が届いた.

Research Products

(11 results)

All Other

All Publications (11 results)

[Publications] Nakajima M, Matsuda H, Hori M: "Persistence and fluctuation of lateral dimorphism of fishes."Am.Nat.. (in press).
[Publications] Abrams PA, Matsuda H: "Population dynamical consequences of reduced predator switching at low total prey densities."Population Ecology. 45(3). 175-185 (2003)
[Publications] Matsuda H: "The importance of the type II error and falsifiability."Eur J Oncol Library. 2. 173-183 (2003)
[Publications] Matsuda H, Serizawa S, Ueda K, Kato T, Yahara T: "Extinction Risk Assessment of Vascular Plants in the 2005 World Exposition, Japan."Chemosphere. 53(4). 325-336 (2003)
[Publications] Abe J, Kamimura Y, Ito H, Matsuda H, Shimada M: "Local mate competition with lethal male combat : effect of competitive assymetry and information availability on a sex ratio game."J Evol Biology. 16. 607-613 (2003)
[Publications] Mori M, Butterworth DS, Brandao A, Rademeyer RA, Okamura H, Matsuda H: "Observer experience and minke whale sighting ability in IWC/IDCR-SOWER surveys."J Cetacean Res Manage. 5. 1-11 (2003)
[Publications] Matsuda H: "Challenges posed by the precautionary principle and accountability in ecological risk assessment."Environmetrics. 14. 245-254 (2003)
[Publications] Matsuda H, Nishimori K: "A size-structured model for stock rehabilitation program of an endemic overexploited bioresouce."Fisheries Research. 60. 223-236 (2003)
[Publications] Katsukawa T, Matsuda H: "Simulated effects of target switching on yield and sustainability of fish stocks."Fisheries Research. 60. 515-525 (2003)
[Publications] Katsukawa(Nakayama) Y, Katsukawa T, Matsuda H: "Indeterminate growth selected by a trade-off between high fecundity and risk avoidance in stochastic environment."Pop Ecol. 44. 265-272 (2003)
[Publications] 中西準子, 益永茂樹, 松田裕之編: "演習環境リスクを計算する"岩波書店. 159-168,169-183 (2003)

2003 Fiscal Year Annual Research Report

魚類群集における反対称捕食の維持機構の数理生態学的研究

Principal Investigator

松田 裕之 東京大学, 海洋研究所, 助教授 (70190478)

Research Products

[Publications] Nakajima M, Matsuda H, Hori M: "Persistence and fluctuation of lateral dimorphism of fishes."Am.Nat.. (in press).

[Publications] Abrams PA, Matsuda H: "Population dynamical consequences of reduced predator switching at low total prey densities."Population Ecology. 45(3). 175-185 (2003)

[Publications] Matsuda H: "The importance of the type II error and falsifiability."Eur J Oncol Library. 2. 173-183 (2003)

[Publications] Matsuda H, Serizawa S, Ueda K, Kato T, Yahara T: "Extinction Risk Assessment of Vascular Plants in the 2005 World Exposition, Japan."Chemosphere. 53(4). 325-336 (2003)

[Publications] Abe J, Kamimura Y, Ito H, Matsuda H, Shimada M: "Local mate competition with lethal male combat : effect of competitive assymetry and information availability on a sex ratio game."J Evol Biology. 16. 607-613 (2003)

[Publications] Mori M, Butterworth DS, Brandao A, Rademeyer RA, Okamura H, Matsuda H: "Observer experience and minke whale sighting ability in IWC/IDCR-SOWER surveys."J Cetacean Res Manage. 5. 1-11 (2003)

[Publications] Matsuda H: "Challenges posed by the precautionary principle and accountability in ecological risk assessment."Environmetrics. 14. 245-254 (2003)

[Publications] Matsuda H, Nishimori K: "A size-structured model for stock rehabilitation program of an endemic overexploited bioresouce."Fisheries Research. 60. 223-236 (2003)

[Publications] Katsukawa T, Matsuda H: "Simulated effects of target switching on yield and sustainability of fish stocks."Fisheries Research. 60. 515-525 (2003)

[Publications] Katsukawa(Nakayama) Y, Katsukawa T, Matsuda H: "Indeterminate growth selected by a trade-off between high fecundity and risk avoidance in stochastic environment."Pop Ecol. 44. 265-272 (2003)

[Publications] 中西準子, 益永茂樹, 松田裕之編: "演習 環境リスクを計算する"岩波書店. 159-168,169-183 (2003)

松田裕之東京大学, 海洋研究所, 助教授 (70190478)

[Publications] 中西準子, 益永茂樹, 松田裕之編: "演習環境リスクを計算する"岩波書店. 159-168,169-183 (2003)