|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1996 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1995 : ¥1,200,000 (Direct Cost : ¥1,200,000)
King crab Paralithodes camtschaticus, P.brevipes and P.platypus hatch out as zoea and metamorphosed into the glaucothoe. In the present study, first, non-feeding of glaucothoe was shown by culture experiment. Food during zoea stage effects survival rate of the glaucothoe ; better survival was shown for the group fed cultured Thalassiosira sp. (diatom) and Artemia nauplii, in combination. The diatom contained about 18% lipids which comprised a quantity of EPA.Second, the foregut was observed in detail as well as the mouthparts ; numerous setae are present in the foregut of zoea, and gastric mill and lateral teeth were formed in the first juvenile, while in the glaucothoe forgut was unarmed with few small setae. Third, metabolic mechanism for the glaucothoe was investigated ; large lipid drops were observed in midgut gland (MGG), midgut gland anterior caecum (AC) and midgut (MG) for the zoea and early glaucothoe, while atrophied AC and elongaed MGG and MG with small lipid droplets for the late glaucothoe. Lipids content showed a drastic decrease during the glaucothoe stage.