Sterol composition of
dark-grown Isochrysis galbana and its implication in the seed
production of Pacific oyster, Crassostrea gigas
Doo
Won Park, QTae Jo, Jeong Lim, B. Véron-2002
Journal of Applied Phycology, 14(5):
351-355
Abstract:
Isochrysis galbana
was cultured heterotrophically with glucose and mannose as a potential food
for larval Pacific oyster, Crassostrea gigas. The food was
evaluated in terms of feeding experiments and changes in sterol composition.
The larvae showed delayed growth and higher mortality compared with ones fed
light-grown material, with a significant difference in mortality from day 8.
Light-grown I. galbana contained three major sterols
(24-oxocholesterol acetate, ergost-5-en-3β-ol,
and cholest-5-en-24-1,3-(acetyloxy)-,3β-ol)
and two minor sterols (24-methylcholesta-5,22-dien-3β-ol
and 24-methylcholest-5-en-3β-ol). The
sterol content decreased markedly after transfer to dark culture, especially
in two of the major sterols, 24-oxocholesterol acetate and ergost-5-en-3β-ol.
The other major sterol, cholest-5-en-24-1,3-(acetyloxy)-,3β-ol,
fall to about 50% of the autotrophic control by day 12. These results
indicate that heterotrophically grown I. galbana is not a favorable
alternative to normally grown material for larval C. gigas culture
as far as sterol composition is concerned.
(National
Fisheries Research and Development Institute, Aquaculture Department, 408-1,
Shirang, Kijang, Pusan, 619-900, Korea, e-mail of QTae
Jo: qtjo@nfrdi.re.kr)