2013 Fiscal Year Final Research Report

The mechanism of polyunsaturated fatty acid synthesis by pond snail and application for conservation of biodiversity.

Research Project

Project/Area Number	24656308
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Single-year Grants
Research Field	Civil and environmental engineering
Research Institution	Tohoku University
Principal Investigator	NISHIMURA Osamu 東北大学, 工学(系)研究科(研究院), 教授 (80208214)
Project Period (FY)	2012-04-01 – 2014-03-31
Keywords	腐食連鎖 / 必須脂肪酸 / マルタニシ
Research Abstract	Essential fatty acids including 20:5n3, 20:4n6 and 22:6n3 have been widely known as important nutrient for animals. Generally, these fatty acids have been considered to be produced by algal species in aquatic ecosystems. In this study, we found that feaces from freshwater snail and fish included these essential fatty acids even these fatty acids were absent in their food sources. We also found that protozoa swarmed on the feaces but almost no protozoa were detected on the food sources which was original of the feaces in the laboratory experiments. Moreover, significant positive relationship between density of protozoa and concentration of essential fatty acid in the feaces were confirmed. It indicate that essential fatty acid in feaces would be attributed to the presence of protozoa. Swarm of protozoa on the feaces seemed to enhance the nutritional quality of feaces in detrital food web.