Revealing of ecological role of the marine eukaryotic micro-organisms, labyrinthulomycetes

2014 Fiscal Year Final Research Report

• Project/Area Number: 23580270
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: General fisheries
• Research Institution: Konan University
• Principal Investigator: HONDA Daiske 甲南大学, 理工学部, 教授 (30322572)
• Project Period (FY): 2011-04-28 – 2015-03-31
• Keywords: ラビリンチュラ / ヤブレツボカビ / 微生物ループ / バイオマス / 季節的遷移 / 棲み分け

Outline of Final Research Achievements

Regular monitoring of estuarine and coastal areas at fixed points was carried out to investigate changes in biomass and species composition of thraustochytrids, which are colorless heterotrophs in the class Labyrinthulomycetes, Stramenopiles. Cell number counts showed that 1 or 2 conspicuous peaks in abundance (termed ‘thraustochytrid spikes’) occurred between spring and late summer in most sampling years. Although thraustochytrid biomass was only 1.59% that of bacterial biomass, the fixed energy (as biomass) transferred directly from thraustochytrids to zooplankton was estimated to be 15.9% of that transferred from bacterioplankton via phagotrophic protists. A similar seasonal succession of phylogenetic groups was observed in each year of sampling. The differences in thraustochytrids isolated at each monitoring site and date suggest that habitat segregation may occur as a result of differences in environmental factors such as water temperature, salinity, and nutrient sources.

Free Research Field

海洋生態学