Studies on stock fluctuation of seasonal cohorts of Japanese flying squid related to the success of reproduction and recruitment
| Project/Area Number |
25292117
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Partial Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Aquatic bioproduction science
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| Research Institution | Hokkaido University |
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Principal Investigator |
Sakurai Yasunori 北海道大学, 水産科学研究科(研究院), 特任教授 (30196133)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Jun 北海道大学, 北方生物圏フィールド科学センター, 助教 (10292004)
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Project Status |
Completed (Fiscal Year 2015)
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| Budget Amount *help |
¥18,330,000 (Direct Cost: ¥14,100,000、Indirect Cost: ¥4,230,000)
Fiscal Year 2015: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
Fiscal Year 2014: ¥7,670,000 (Direct Cost: ¥5,900,000、Indirect Cost: ¥1,770,000)
Fiscal Year 2013: ¥7,020,000 (Direct Cost: ¥5,400,000、Indirect Cost: ¥1,620,000)
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| Keywords | スルメイカ / 再生産仮説 / 大型水槽 / 産卵行動 / ふ化幼生 / 有機懸濁物 / 気候変化 / 資源変動予測 / 再生産仮設 / 生涯１回産卵 / 卵塊の中層浮遊 / 初期餌料 / 再生産 / GIS解析 / 飼育実験 / 人工授精 |
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| Outline of Final Research Achievements |
The experiment was conducted to test the reproductive hypothesis of Todarodes pacificus in a large tank (200 tons). The maturation process untill spawning were controled by temperatures during 13 and 20°C. Ripe females and males were released into the large tank.The egg masses were observed suspended in the thermocline. However, without the thermal gradient,egg masses collapsed on the bottom, and eggs were infested by microbes.Twenty-one females spawned 39 egg masses (30 to 120 cm diameter).The paralarvae survived for up to 13 days, which was suggested that they fed on DOM with marine bacteria.
Annual catches of fall cohort are gradually decreasing after 2000s.The inferred spawning area was covered by warm surface water above 24°C . However, annual catches of winter cohort are stable after 2000s. The inferred spawning area was formed along continental slope in the East China Sea. The fishing area shifted to more northern area and the southward migration was delayed by December.
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Report
(4 results)
Research Products
(34 results)
