夜行性ホークモスにおけるスコトピック色覚
Almut Kelber1, Anna Balkenius, Eric J Warrant
1Department of Cell and Organism Biology, Vision Group, Lund University, Helgonavägen 3, S-22362 Lund, Sweden. almut.kelber@zool.lu.se
Nature
|November 1, 2002
まとめ
夜行性ホークモスには色覚があり,暗闇の星光下でも夜中に物体を見分けることができます. この発見は,すべての動物が弱光条件下では色盲であるという仮定に異議を唱えている.
科学分野:
- 動物の行動 動物の行動
- センサリーエコロジー センサリーエコロジー
- ビジョン ビジョン 科学 科学
背景:
- 人間は,低光条件下では機能的に色盲です.
- カラービジョンは,昼も夜もオブジェクトの差別に不可欠です.
- 以前の仮定では,夜行性の動物には色覚が欠けていると考えられていた.
研究 の 目的:
- 夜間ホークモスが薄暗い光下でも色覚を活用しているかどうかを調査する.
- ホークモスが色定数を示すかどうかを判断する.
- 夜行性昆虫における色彩視の生態学的関連性を評価する.
主な方法:
- 行動に関する実験は,ホークモス種 *Deilephila elpenor* を用いて行われました.
- 刺激は,薄暗い星光 (0,0001 cd x m(-2)) を真似た光の強さで提示されました.
- 色定数は,照明の色を変えることでテストされました.
主要な成果:
- ホークモスは,スコトピック光レベルでの色彩刺激を区別する能力を実証しました.
- 蝶は,光の変化にもかかわらず,その知覚を調整して,色の定常性を示した.
- これとは対照的に,人間は同じ条件下で完全に色盲であった.
- 計算により,光受容体の3つのクラスを持つことは,絶対的な感受性を低下させるにもかかわらず,夜行性にとって生態学的に重要であることが示されました.
結論:
- 夜間ハークモスには,以前は不十分と考えられていた光の強度でも機能的な色覚があります.
- ホークモスにおける色の定常性は,夜間環境に適応した洗練された視覚システムを示している.
- この発見は,夜行性昆虫の色彩視の重要な生態学的役割を強調し,長年にわたる仮定に異議を唱える.
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