1995 Fiscal Year Final Research Report Summary
COMMUNITY STUDIES ON THE BIOLOGICAL PRODUCTION PROCESS OF MYSID INHABITING IN THE SURF ZONE OF SANDY COAST.
| Project/Area Number |
05454089
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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 |
General fisheries
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
OKATA Akihiro TOHOKU UNIVERSITY FACULTY OF AGRICULTURE PROFESSOR, 農学部, 教授 (50241550)
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| Co-Investigator(Kenkyū-buntansha) |
ITO Kinuko ISHINOMAKI-SENNSHUU UNIVERSITY SCIENCE & TECHNOLOGY ASSISTANT, 農学部, 助手 (90191931)
KATAYAMA Satoshi ISHINOMAKI-SENNSHUU UNIVERSITY SCIENCE & TECHNOLOGY ASSISTANT, 農学部, 助手 (30224455)
HONDA Hitoshi ISHINOMAKI-SENNSHUU UNIVERSITY SCIENCE & TECHNOLOGY ASSISTANT, 農学部, 助手 (90165613)
OMORI Michio ISHINOMAKI-SENNSHUU UNIVERSITY SCIENCE & TECHNOLOGY ASSIST.PROFESSOR, 農学部, 助教授 (60152253)
SUGAWARA Yoshio ISHINOMAKI-SENNSHUU UNIVERSITY SCIENCE & TECHNOLOGY PROFESSOR, 理工学部, 教授 (20005614)
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| Project Period (FY) |
1993 – 1995
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| Keywords | mysid / sandy beaches / surf zone / biological production process / slope of beach / daily feeding rate / conversion rate / ^<14>C / cohort |
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| Research Abstract |
In order to make clear the functional role of the sandy surf zone in a coastal ecosystem, the authors investigated the biological production process of a mysid Archaeomysis kokuboi in the Sendai bay.
The summary of the results is shown below.
1) In the Sendai bay, a misid A.kokuboi has a large standing crop in the sandy beaaches of surf zones all the year round. The abundance of the mysid is high especially in areas shallower than 5m in depth.
2) High density distribution area of the mysid on the slope of beaches moves accompanying the tide and has a constant distance from the low tide lines. The median size of sediment of the main habitat for the mysid is 2.0-2.3. In the daytime most of the mysid are burrowing in the surface layr (0-3cm in depth) of the sand slope, and by night they are swimming in the water and feeding mainly on flagellates and copepods.
3) Daily feeding rates of the mysid fed with brine shrimps for food, under the conditions of 15ﾟC in water temperature and 0-100 lux in illuminance, are 24.8% in wet weight and 39.7% in dry weight.
4) Conversion rates of the food ingested to the mysid decrease with the growth ; from 24.6-44.2% in young stage to 8.9-13.8% in adult. The ratios of the amount of substance remained in the body of mysid and that ingested brine shrimp labeled with ^<14>C are 52% for 12 hours and 38% for 24 hours after feeding.
5) A.kokuboi has a possibility of spawning at least more than two times throughout the life, and for the population it is recognized that they have more than 6 cohorts in one year. Cohorts bone during the warm season April-June grow fast to mature in a small size, and that bone during the cold season November-January grow slowly and spawn their eggs in spring as the larger sized adult.
6) These studies clearly show that A.kokuboi plays an important role as a key species in the sandy surf zone ecosystem sustaining the basic processes in a coastal biological production.
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