| Project/Area Number |
17K19300
|
|---|
| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Forestry and Forest Products Science, Applied aquatic science, and related fields
|
|---|
| Research Institution | Nihon University |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2017-06-30 – 2019-03-31
|
| Project Status |
Completed (Fiscal Year 2018)
|
| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000)
Fiscal Year 2018: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2017: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
|
|---|
| Keywords | ウナギ / レプトセファルス / 初期餌料 / 種苗生産 / マリンスノー |
|---|
| Outline of Final Research Achievements |
To develop a new type of larval diet for leptocephalus larvae of the Japanese eel, the ingredients of marine snow on which the leptocephali feed in the wild were analyzed. The majority was carbohydrate (81.0%), and protein (12.7%), lipid (6.3%) in order. Liquid-type diet (viscosity: 58 mPa・s) improved larval growth and survival with more and denser diet ingested in the intestine than conventional slurry-type diet (10^3-10^5 mPa・s) during 3 weeks after the onset of feeding. Long-term rearing for 259 days after hatching by immersing larvae in the liquid-type diet, five times a day for 10 minutes each, showed better survival (37-59%) and more glass eel production (1.1~3.2 times) in liquid-type diet than in conventional slurry-type diet (survival; 11-25%).
|
| Academic Significance and Societal Importance of the Research Achievements |
天然海域でウナギレプトセファルスの餌となっているマリンスノーの成分と物性を詳しく検討した結果，これまでに全くないタイプの初期餌料として「液体餌」が開発された．この液体餌は，成長率と生残率を著しく改善し，仔魚の初期餌料と給餌方法の革命になる可能性がある．また，半世紀もの長い間の挑戦的研究にもかかわらず，依然として実用化の道のりの遠かったウナギ人工種苗生産技術の開発研究に大きなブレークスルーをもたらすものと考えられる．
|
