| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1987: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1986: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
Diarrehtic shellfish poisoning (DSP) is intoxification of shellfish which feed on dinoflagellates, Dinophysis spp.. DSP causes extensive impacts on fisheries industries in Japan as well as in European countries. As nobody have ever suceeded in culturing Dinophysis spp., physiological and ecological character of Dinophysis and the mechanism of the toxin production by the species are still unclear. Purposes of the present study are to make clear the nutitional style of Dinophysis and to establish culture method for them.
At a first step, osmotrophic growth was tested. Cells of D. fortii were inoculated to enriched seawater media containing various organic compaunds. No growth were observed in axenic condition but some cells were survived in media contaminated with bacteria. Growth was also observed in seawater filterd by plankton net containing microflagellates. Thus, osmotrophy of D. fortii was denied but Phagotrophy was sugested. Then, Phagotrophic growth was tested by culturing D.fortii, D. acuminata and D. caudata with various species of micro algae as foods. As these Dinophysis species have orange fluorescence of phycobilin, cyanobacter or cryptomonad were thought to be contained in the cells of them. A cryptomonad, Plagioselmis sp. was observed to taken into the cells of 3 Dinophysis spp.. Growth of D. fortii and D. caudata were observed in culturing with Plagioselmis sp., but did not increase in large cell number. In order to establish cultures of Dinophysis spp., It is needed to study other factors which affect the growth of the species.
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