Host-parasite relationship between chytrid and harmful dinoflagellates in sediment of the marine environment

2014 Fiscal Year Final Research Report

• Project/Area Number: 24580289
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: General fisheries
• Research Institution: Fisheries Research Agency
• Principal Investigator: YAMAGUCHI Mineo 独立行政法人水産総合研究センター, 瀬戸内海区水産研究所, 主幹研究員 (00371956)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 菌類 / ツボカビ / 有毒プランクトン / 寄生 / 渦鞭毛藻 / 海洋 / 海底堆積物

Outline of Final Research Achievements

During the germination experiments of the cysts by incubating sediment suspensions, we have found epibiotic and endobiotic fungal parasites on the germinated cells and/or the cysts of marine dinoflagellates Alexandrium tamarense and Scrippsiella trochoidea. In the present study we characterized and identified these fungi by microscopic observation and rDNA sequence analysis. Results showed that the epibiotc fungi belonged to the Rhizophydium clade or Lobulomycetales, Chytridiomycota. We also succeeded in obtaining culturable strain of Rhizophydium from Ofunato Bay for the first time. Although taxonomic position of the endobiotic fungus yet to be identified, it belonged to neither “core chytrid clade” nor Oomycota. Our finding indicates that a variety of fungal parasites can have significant impacts on marine dinoflagellates and parasitism needs to be considered in understanding of their bloom dynamics.

Free Research Field

海洋環境微生物学