水温と塩分が餌料候補種 Eutreptiella sp. の増殖に与える影響

Effects of temperature and salinity on the growth of Eutreptiella sp.

Creators Ishii Keita

Creators Yamasaki Yasuhiro

Creators Abe Mahiko

Creators Murase Noboru

We conducted the growth experiments using a crossed factorial design with 9 combinations of 3 temperatures (15, 20 and 25℃) and 3 salinities (20, 25 and 30 psu), and growth characteristics of the euglenophyte Eutreptiella sp. and six kinds of diet microalgae (the diatom Chaetoceros neogracile, C. muelleri, Thalassiosira sp., T. pseudonana, haptophytes Diacronema lutheri (syn. Pavlova lutheri) and Isochrysis galbana) were compared. As a result, Eutreptiella sp. showed steady growth under a wide range of culture conditions, and this species could grow well under low water temperature. In addition, maximum growth rate of Eutreptiella sp. was 1.84 ± 0.15 divisions day^{-1}, and was obtained at the combination of 15℃ and a salinity of 20 psu. In contrast, maximum growth rates of other six diet microalgae decreased with decreasing water temperature. Thus, Eutreptiella sp. has a potential to be a new diet alga for the seeding production of mollusks during late fall and early summer.

[ISSN]0370-9361