Biological Study on the Increment of Survival Rate during Early Life Cycle in the Rockfish, Sebastes schlegeli (Teleostei: Scorpaenidae) - II. Energy Budget of the Larvae and Juveniles Stages

조피볼락, Sebastes schlegeli의 초기생활사 동안 생존율 향상을 위한 생물학적 연구 - II. 자치어기의 에너지수지

In order to estimate energy budget of the rockfish, Sebastes schlegeli juvenile, during the period from parturition to juvenile, of rockfish were reared at constant condition of water temperature($16^{\circ}C$ and $20^{\circ}C$). Energy used by the reared juveniles were calculated from estimates of data on growth, oxygen consumption, nitrogen excretion, feeding and energy content. After parturition, total length of juvenile was 4.56~5.49mm(average 4.97mm, n=20), and the average dally growth rates were 0.50mm at $20^{\circ}C$. The weight-specific oxygen consumption and nitrogen excretion rates decreased with increasing body weight. Temperature significantly affected oxygen consumption and nitrogen execretion rates, with the higher rates at $20^{\circ}C$ than $16^{\circ}C$. During the 25 days from parturition to jllveniles, feeding rates were 65.8cal at $16^{\circ}C$, and 89.2cal at $20^{\circ}C$. The assimilation effeciency estimated by nitrogen content of food and egested feces were 85.21% at $16^{\circ}C$ and $20^{\circ}C$. During the period from parturition to juvenile, energy was used the higher in body growth than in oxygen consumption. The gross growth efficiencies($K_1$)and net growth efficiencies($K_2$) of the rockfish, Sebastes schlegeli juvenile ranged from 43% to 47% and from 50% to 55%, respectively.

조피볼락의 출산 후부터 치어기에 이르기까지 경과한 일수별로 성장, 호홉, 배설, 섭식 및 동화효율 등을 측정하여 에너지수지를 분석하였다. 출산후 자어의 전장은 4.56~5.49mm (평균 4.97mm, n=20)였으며, $20^{\circ}C$에서 1일 평균 성장률은 0.50mm였다. 출산후 경과일수에 따른 건중의 관계식은 $16^{\circ}C$에서 DW=$0.0380e^{0.1120D}$($r^2$=0.9049), $20^{\circ}C$에서 DW=$0.0324e^{0.1394D}$($r^2$=0.9239)였다. 비체중 산소 소비율 및 암모니아 질소배설률은 개체의 크기가 증가할수록 감소하였으며, $16^{\circ}C$에 비해 $20^{\circ}C$에서 높았다. 섭식율은 $16^{\circ}C$에서 자치어기의 25일 동안 65.8cal를, $20^{\circ}C$에서는 89.2cal를 섭취하여 $20^{\circ}C$에서 높게 나타났다. 동화효율은 수온에 따라 차이는 없었으며, 출산 후 20일째에는 $16^{\circ}C$와 $20^{\circ}C$에서 86.2% 였다. 출산 후 치어로 성장하는 동안 호홉에 비해 체성장에 더 많은 에너지를 이용하였으며, 수온이 높을수록 성장률이 빠르게 나타났다 출산 후부터 치어로 성장하는 동안 누적 섭식에너지에 대한 총성장효율은 43%~47%, 순성장효율은 50%~55% 였다.