| Project/Area Number |
06455004
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
広領域
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| Research Institution | Chiba University |
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Principal Investigator |
SAKAKI Yo Chiba University, Faculty of Engineering, Professor, 工学部, 教授 (80005280)
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| Co-Investigator(Kenkyū-buntansha) |
OGURA Miki Fisheries Agency, Tohoku National Fisheries Research Institute, Chief Scientist, 資源管理部, 研究室長
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥5,500,000 (Direct Cost: ¥5,500,000)
Fiscal Year 1995: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1994: ¥4,000,000 (Direct Cost: ¥4,000,000)
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| Keywords | Chum salmon / Sockeye salmon / Hime salmon / Migration / Magnetic compass / Behavioral test in magnetic field |
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| Research Abstract |
(1)Extraction of tissue including magnetic substance :
A tissue including magnetic substances was extracted from the head of chum salmon and analyzed using SEM.The magnetic substances localized in several points of the tissue. The magnetic substance was composed of compound of iron and oxygen and the texture is like the meshes of a net.
(2)Behavioral test for magnetic sensitivity of hime salmon :
Mature hime salmon were tested for their magnetic sensitivity using a successive conditioning. Fish were reinforced accoding to a change of the magnetic field as a conditioned stimulus and an electric shock as an unconditioned stimulus. No statistically significant conditioned reflex was observed in the fish. However, the fish were successfully conditioned by lighting stimulus instead of the magnetic stimulus. These results suggests that mature hime salmon were not so sensitive to magnetic field as light.
(3)Ultrasonic telemetry for investigating the magnetic compass orientation :
We investigated the magnetic compass orientation of the ocean migrating chum salmon off the coast of Kushiro in the western North Pacific in 1994 and 1995. Salmon with anultrasonic transmitter and an artificial magnetic field generator which disturbs the geomagnetic field around the posterior part of the head were tracked. Just after releasing the salmon, the magnetic field generator was off and the salmon swam under normal geomagnetic field for several hours. In the susequent 16 hours, the magnetic field generator induced an altanative magnetic field whose intensity was about 6 gauss and the polarity was reversed every 11.25 min to the posterior part of the head. We collected information on the horizontal and vertical movements of the fish under the normal and disturbed field using the ultrasonic telemetry. No significant change of movements were found between the two conditions.
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