Abstract
The growth and size variation of rotifer (Brachionus plicatils) were examined at the various water temepratures ranging form 18 to $36^{\circ}C$, and under continuous light condition. Either Chlorella ellipsoidea or $\omega$-yeast were fed to rotifer as a food organism. Compared to large-type rotifer fed of $\omega$-yeast, those fed on C. ellipsoildea generally showed higher growth at 7th after starting culture under the water temperaure of less than $30^{\circ}C$. Above such temperature, the large-type rotifer fed on $\omega$-yeast showed higher growth rather than those fed on C. ellipsoidea and the maximum cell number reached 1,420 ind./m$\ell$ at $36^{\circ}C$, whereas when the small-type rotifer was fed on $\omega$-teast, its maximum cell number was to be 1,669 ind./m$\ell$at $34^{\circ}C$. The striking decrease in size was found in large-type rotifer which was to be $112.1\mu m$m(initial : 202.0${\mu}{\textrm}{m}$) when they were fed on C. ellipsoidea at $34^{\circ}C$ for 5 days after starting culture. A great increase in size from the initial of 157.0 to $201.3\mu m$mwas show in small-type rotifer fed on $\omega$-yeast at $20^{\circ}C$,for 5 days. The present results demonstrated that size variation of rotifer could be controlled by changing culture temperature.
배양온도, 먹이생물의 종류에 따라 rotifer 의 성장과 세포크기변화를 알아본 결과 다음과 같다. Large-type rotifer 의 최대세포수는 온도 $36^{\circ}C$, 먹이생물 $\omega$-yeast를 공급한 것에서 배양 7일후 1,420 ind./ml, small-type rotifer에서는 온도 $34^{\circ}C$, 먹이생물 $\omega$- yeast를 공급한 것에서 배양 7일후 1,669 ind./ml로 최고의 성장을 보였다. Rotifer의 크기변화에서는 large-type의 경우 온도 $34^{\circ}C$, 먹이생물 C. ellipsoidea를 공급한 실험구에서 $112.1\mu m$까지 감소되었다 (실험시작시 $202.0\mu m$. Small-type rotifer의 경우는 $320^{\circ}C$, $\omega$-yeast를 먹이로 공급한 것이 배양시작 5일후 $201.3\mu m$까지 증가되었다 (실험시작시 $157.0\mu m$. 크기의 변화가 큰 rotifer에 온도 변화를 다시 주었을 때 처음 실험 시작 때의 rotifer 크기로 회복되었다.
