초록
넙치 수정란의 발생에 미치는 수온의 영향을 조사하였다. 실험에 사용된 수정란은 실내 사육수조에서 자연산란된 것으로서, 6개의 수온별 실험구(5, 10, 15, 20, 25 및 $30^{\circ}C$)에 수용하여 발생과정을 관찰하였다. 수정란은 10, 15, 20 및 $25^{\circ}C$에서 부화 가능하였으며, 부화율은 각각 3, 12, 25 및 50%였다. 발생단계별 수온(T, $^{\circ}C$)과 소요 시간(1/t, hour)과의 상관관계식은 다음과 같다. 포배기: 1/t=0.0208T-0.0951 ($r^2$=0.8593) 쿠퍼씨포기: 1/t=0.0052T-0.0176 ($r^2$=0.9819) 근절기: 1/t=0.0034T-0.0172 ($r^2$=0.8508) 부화: 1/t=0.0016T-0.0068 ($r^2$=0.9915) 위 식을 이용하여 산정한 넙치 난 발생의 생물학적 영도는 $4.3^{\circ}C$였다.
This study was performed to examine the influence of water temperature on egg developmental speed for determining the required time and optimum water temperature for hatching of olive flounder Paralichthys olivaceus eggs. The fertilized eggs were collected from the naturally spawned adults in November 2007. The eggs were randomly divided into 6 groups of temperature (5, 10, 15, 20, 25 and $30^{\circ}C$) and transferred in $1{\ell}$ beaker, respectively. The fertilized eggs of the olive flounder did not hatched at $5^{\circ}C$ and $30^{\circ}C$ and hatching rates at 10, 15, 20 and $25^{\circ}C$ were 3, 12, 25 and 50%, respectively. The relationships between the water temperature (T, $^{\circ}C$) and required time (1/t, hour) from egg to each developmental stage were given as follows ; Blastula: 1/t=0.0208T-0.0951 ($r^2$=0.8593) Kupffer's vesicle: 1/t=0.0052T-0.0176 ($r^2$=0.9819) Myotome: 1/t=0.0034T-0.0172 ($r^2$=0.8508) Hatching: 1/t=0.0016T-0.0068 ($r^2$=0.9915) Biological minimum temperature in egg development was calculated to be $4.3^{\circ}C$.
