similarities in meiofaunal composition among hydrothermal vents in meiboring seamounts

2016 Fiscal Year Final Research Report

• Project/Area Number: 26440246
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Ecology/Environment
• Research Institution: Kumamoto University
• Principal Investigator: Shimanaga Motohiro 熊本大学, 沿岸域環境科学教育研究センター, 准教授 (70345057)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 深海熱水噴出域 / メイオベントス / 群集構造

Outline of Final Research Achievements

We studied the variations in meiofaunal composition and their nutrition sources around hydrothermal vents and in the adjacent non-vent fields in the calderas of three neighboring seamounts in Izu-Ogasawara Arc, NW Pacific. Nematodes were the most abundant in the sediments on seafloor in the non-vent fields. Around some vents, Stygiopontius (Dirivultidae, Siphonostomatoida), a typical vent copepod group, was predominant. Genetic analyses on Stygiopontius from different seamounts showed they are the same species, and population-level analyses based on partial mitochondrial DNA sequence suggested the gene flow occurs between seamounts, even though they are separated from each other at 30 km scale. Stable carbon isotopic ratios and natural-radiocarbon abundances of meiofauna revealed the dirivultid copepods utilized mainly chemolithoautotrophic microbes. The other copepods (mainly harpacticoids) at the same habitats rely on them to a certain degree.

Free Research Field

海洋生態学