条石鲷的耗氧率与窒息点研究

Study on the oxygen consumption rate and asphyxiation point of rock bream Oplegnathus fasciatus

中文关键词: 条石鲷  耗氧率  窒息点  昼夜变化

英文关键词: Rock bream Oplegnathus fasciatus  Oxygen consumption rate  Asphyxiation point  Diurnal variation

中文摘要:

      2008年4～8月，采用Winkler法研究了70日龄（平均全长37.68mm，平均体重1.07g）和105日龄（平均全长5.71mm，平均体重5.58g）的条石鲷在不同温度（15、20和25℃）、不同盐度（20、25和30）下的耗氧率、窒息点及耗氧率昼夜变化。结果表明，105日龄组的相对耗氧率明显低于70日龄组，但个体耗氧量明显高于70日龄组；耗氧率随幼鱼体重的增加而相对减少。盐度一定时，温度升高，相对耗氧率和个体耗氧量都随之增大。盐度对70日龄幼鱼组的耗氧率影响显著（P＜0.05），对105日龄幼鱼组影响不显著（P＞0.05）。盐度25左右、温度20～25℃时是条石鲷苗种培育和生长的最适盐度和最适温度。条石鲷在温度15-25℃、盐度20~30下的窒息点为1.602 1-2.953 8 mg O2/L，窒息点随着个体的增大而降低；温度、盐度对条石鲷窒息点的影响均不显著（P＞0.05）。条石鲷耗氧率的昼夜变化明显，白天的耗氧率平均为0.945 9mg O2/g·h，夜间平均为0.272 7mg O2/g·h，白天的耗氧率是夜间的3～5倍，条石鲷白天代谢旺盛并持续到夜间22∶00左右。

英文摘要:

      Studies on the oxygen consumption rate, its diurnal variation and asphyxiation point of rock bream Oplegnathus fasciatus at different salinities (20, 25, 30) and temperatures (15℃, 20℃, 25℃) were carried out in Qingdao Zhonghai Fishery Corporation, Ltd. from April to August, 2008. The experimental fish were divided into two groups: 70d-old group at an average body weight of 1.07g and an average body length of 37.68 mm; 105d-old group at an average body weight of 5.59g and an average body length of 65.71 mm. The results showed that relative oxygen consumption rate of 105d-old fish was significantly higher than that of 70d-old fish, while the asphyxiation point of the former was lower. The oxygen consumption rate of rock bream decreased as their body weight increase. Both relative oxygen consumption rate and individual oxygen consumption increased with the rise of water temperature when salinity was unchanged. The effect of salinity on oxygen consumption rate of 70d old fish was significant (P＜0.05) whereas it was not significant for 105d-old fish (P＞0.05). The optimum salinity for growth of rock bream was 25, and the optimum temperatures were 20～25 ℃. The asphyxiation point of rock bream were between 1.602 1 mg O2/L and 2.953 8 mg O2/L at different temperatures and salinities and it decreased with the increase in body weight. Neither salinity nor temperature had significant effects on which (P＞0.05). The oxygen consumption rate of the young fish was 0.945 9 mg O2/g.h in daytime, which was about 3-5 times higher than the nighttime. Rock bream showed high metabolism rate till 22∶00pm. 