Understanding of the ecological characteristics and genetic variation of symbiotic zooxanthellae within giant clam for stable seed production of giant clam species

2016 Fiscal Year Final Research Report

• Project/Area Number: 26660164
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Aquatic bioproduction science
• Research Institution: Fisheries Research and Education Agency
• Principal Investigator: Yamashita Hiroshi 国立研究開発法人水産研究・教育機構, 西海区水産研究所, 研究員 (00583147)
• Research Collaborator: Kondo Shi-nobu 沖縄県水産海洋技術センター ; Minami Yoichi 沖縄県水産海洋技術センター ; Inoue Ken 沖縄県水産海洋技術センター ; Ikeda Shota 広島大学 ; Osada Hiroki 広島大学 ; Morishima Shin-ya 広島大学 ; Mukai Kazuma 広島大学
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 増養殖 / 水産学 / 生態学 / 共生生物学 / 生物圏現象 / 褐虫藻 / シャコガイ / 種苗生産

Outline of Final Research Achievements

We investigated Symbiodinium clade compositions within two giant clam species, Tridacna crocea and Tridacna squamosa, maintained in the same outdoor pond. Most of T. crocea harbored only clade A Symbiodinium, whereas multiple clades were detected within most of T. squamosa. In the case of T. squamosa, along with increasing the clam size, the main dominant clade shift clade A to C, and decreases in Symbiodinium genetic diversity. In the laboratory experiment using T. squamosa larvae, there is an increased mortality rate of the larvae when stopped Symbiodinium cell supply. We then introduced these information to seed production of T. squamosa. Namely, Symbiodinium that is considered to have high genetic diversity squeezed out from small T. squamosa was supplied constantly to T. squamosa larvae. The symbiosis rate of this method was about two times higher than that of traditional method.

Free Research Field

微細藻類学・共生生物学・生物海洋学