| Project/Area Number |
02660188
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
General fisheries
|
|---|
| Research Institution | The university of Tokyo |
|---|
Principal Investigator |
HINO Akinori The university of Tokyo, Faculty of Agriculture, Assoc. Prof., 農学部, 助教授 (90012012)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
IIDA Takaji The university of Tokyo, Faculty of Agriculture, Assistant Prof., 農学部, 助手 (70159557)
OGAWA Kazuo The university of Tokyo, Faculty of Agriculture, Assistant Prof., 農学部, 助手 (20092174)
|
|---|
| Project Period (FY) |
1990 – 1991
|
| Project Status |
Completed (Fiscal Year 1991)
|
| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1991: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1990: ¥1,400,000 (Direct Cost: ¥1,400,000)
|
|---|
| Keywords | rotifer / stable isotope / Brachionus plicatilis / bacteria / protozoa / food web / 物質循環機構 |
|---|
| Research Abstract |
This study intended to know the function of both protozoa and bacteria in the culture of the rotifer Brachionus plicatilis, as a part of researches on the massmortality or stagnan growth which disturbs the planned production of marine animal seedlings
I. Function of protozoa and bacteria in food web
Incredible value of 53.8-70.8% was obtained in nitrogen conversion rate of the rotifer, when calculated on the whole culture period. Moreover, for daily nitrogen balance, the nitrogen fed to the animal(1.89xlO^<-8>gN/day/rotifer)was far less than the total of growth(1.42)and excretion(2.69). Those results suggested that the rotifer ingested organic substances other than algae or yeasts provided as food. Evaluation with Particle Counter revealed that both bacteria and drotozoa increasing by the use of rotifer's excretion were ingested after forming flocs, which was nearly equal to the value for algae or yeasts.
The bacterial strain which showed remarkable growth promotion for the rotifer was isolated, and it belonged to Pseudomonas.
II. Function of bacteria as a growth-inhibiting factor
The strain Y5 which had been isolated on the occasion of sudden death of the rotifer had acute virulence to the rotifer, and the 24 hrs' LD_<50> was 4-5 Log CFU/ml, which may be a causative organism of the sudden massmortality.
III. Function of bacteria on the energy and substance flow in rotifer culture
|
