| Budget Amount *help |
¥13,000,000 (Direct Cost: ¥13,000,000)
Fiscal Year 1985: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1984: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1983: ¥7,000,000 (Direct Cost: ¥7,000,000)
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| Research Abstract |
1. We tried to establish the method to rear juvenile sea urchins from fertilized eggs in the marine laboratories where the equipment for aquaculture is not fully available.
2. We could obtain several thousands of juvenile sea urchins in 7 species, Pseudocentrotus depressus, Anthocidaris crassispina, Hemicentrotus pulcherrimus, Temnopleurus toreumaticus, Echinostrephus aciculatus, Strongylocentrotus nudus and Mespilia globulus.
3. Pluteus lavae were kept in 25 litter paper-filtered sea water in 30 litter plastic vessels (6 plutei/ml). A diatom, Chaetoceros gracilis, was found to be the most suitable food of the larvae.
4. When the larvae reached 8-arm stage and the sea urchin primordium grew large enough within them, they were transferred into a 500 litter plastic vessel and given plastic plates which were covered by diatoms. The larvae immediately began metamorphosis on the plates.
5. The juveniles were fed by sea weeds such as Ulva and Sargassum. When they became 5-10 mm, they were released into the sea.
6. The maximum number of juveniles obtainable from a 500 litter vessel will be 10,000.
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