まとめ
研究者らは,ガラパゴス島の熱水噴出孔のクラゲを研究し,その成長率を決定するためにウラン・ソリウム分解系列を用いた. この分析により,クラゲは1年に約4センチメートル成長し,年齢は3~4歳であることを示した.
科学分野:
- マリン・バイオロジー マリン・バイオロジー
- 地質化学 地質化学
- ラジオメトリック・デッティング
背景:
- Vesicomyid clamsは,深海の熱水噴出口の生態系に生息しています.
- 深海の生物の成長率を理解することは,生態学の研究にとって極めて重要です.
- 熱水噴出孔は,生物学的および地質学的研究のためのユニークな環境を提供します.
研究 の 目的:
- ガラパゴス広場にあるベシコマイドクジラの成長率を測るため.
- ウランとトリアの分解系から放射性同位素を用いて標本を老化させる.
主な方法:
- 貝殻のサンプルは,生きた19cmのベシコマイド貝から成長線に沿って採取した.
- 分析は,ウラン-238 (238U) とソーリウム-232 (232Th) 崩壊シリーズのメンバーに焦点を当てた.
- 成長率は,ポロニウム-210/鉛-210 (210Po/210Pb) とトーリウム-228/ラジウム-228 (228Th/228Ra) の同位素ペアを用いて計算された.
主要な成果:
- クラゲは,最長軸に沿って年間約4センチメートルの成長率を示しています.
- 殻の最大成長軸は12センチメートルである.
- 決定された成長率は,この個体クラームの年齢が3〜4歳であることを示唆しています.
結論:
- 殻の成長線の放射性同位体年代測定は,深海のクラゲの老化のための信頼できる方法を提供します.
- 急速な成長率は,ガラパゴス島の熱水噴出口環境における重要な生物学的活動を示している.
- この研究は,化学合成生態系における生命の歴史戦略の理解に貢献します.
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