1988 Fiscal Year Final Research Report Summary
Studies on daily rhythmic activities in aquatic animals
| Project/Area Number |
62304022
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
General fisheries
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| Research Institution | The University of Tokyo |
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Principal Investigator |
HANYU Isao Professor, The University of Tokyo, Faculty of Agriculture, 農学部, 教授 (20011835)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Kaworu Assistant Prof. Kagoshima University, Fac. of Fisheries, 水産学部, 助教授 (40041719)
OMURA Yuri Research Assist., Nagoya University, Fac. of Agriculture, 農学部, 助手 (50023479)
SAKAMOTO Wataru Assistant Prof. University of Kyoto, Fac. of Agriculture, 農学部, 助教授 (50013587)
YAMAMORI Kunio Assistant Prof. Kitasato University, Fac. of Fisheries, 水産学部, 助教授 (80012029)
MUGIYA Yasuo Assistant Prof., Hokkaido University, Fac. of Fisheries, 水産学部, 助教授 (50001615)
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| Project Period (FY) |
1987 – 1988
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| Keywords | daily activity / Otolith / melatomin / pineal gland / biological clock / Shell opening and closing rhythm / clam / kuruma prawn / クルマエビ / アカウミガメ |
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| Research Abstract |
A: The opening and closing rhythm of the shell in the clam Veuerupus philippiuarum was investigated. The number of individuals exhibiting shellclosing peaked twice a day, coinciding with low tide. These results suggest that the clam posesses circatidal rhythm.
B: In Kuruma prawn, daily rhythm was observed in feeding behavior. Under a 12L12 photoperiod and a corresponding reversed photoperiod, active feeding gehavior was observed only in the dark phase. Existence of biological clock was also confirmed in the eyestalk.
C: To investigate the daily growth rhythm in fish otoliths, rainbow trout larva were reaed under 6L6D, 12L12D, 24L24D, DD and LL conditions. Under a 12L12D condition, one ring was added daily to the otolith. under 6L6D 2 rings were formed daily, whereas under 24L24D two days were needed to form a ring. Under DD and LL conditions, 20.9 and 17.6 rings were formed during 15 days, respecitively.
D: Daily change were observed in the number of synaptic ribbons and the degeneration of outer segment of photoreceptor cells in the pineal gland.
E: RIA for melatonin has been established. Subsequently, daily changes in plasma melatonin levels were investigated using common carp reared under both long and short daylength. Plasma melatonin levels were high during the dark phase, but low during the light phase for both photoperiods.
F: In order to investigate daily swimming rhythm on loggerhead turtle caretta caretta, a recorder was attached to the back of the mother at spawning. Subsequently, during the next spawning one month following, data were collected. From analysis of this data, the existence of a daily swimming rhythm was confirmed.
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