福尔马林处理对石斑拟合片盘虫和斜带石斑鱼的影响

20 0 0年 4月研究了斜带石斑 Epinepheluscoioides寄生拟合片盘虫Pseudorhabdosynochusepinepheli的防治方法。海水福尔马林对拟合盘虫的作用表现为 :2 5min处理的半致死浓度为 2 5 0× 10 - 6 ,5 0min处理的半致死浓度为 5 0× 10 - 6 。淡水福尔马林的效果为 :3min的半致死浓度为 83× 10 - 6 ,纯淡水处理的半致死时间为 2 1min。海水福尔马林对斜带石斑的毒性表现为 :30min和 4 5min的半致死浓度分别为 94 0× 10 - 6 和 6 4 5× 10 - 6 。淡水福尔马林对斜带石斑的毒性表现为 :5min和 10min的半致死浓度分别为 130 0× 10 - 6 和 5 0 0× 10 - 6 。福尔马林处理海水中的斜带石斑半致死浓度介于 6 0 0× 10 - 6 ～ 10 0 0× 10 - 6 ,淡水处理对斜带石斑半致死浓度介于 95× 10 - 6 ～ 115×10 - 6 。淡水中斜带石斑的半麻醉和半致死时间分别为 95min和 115min。以上结果表明 :海水和淡水福尔马林对石斑拟合片盘虫的致死浓度 ,处于斜带石斑的安全范围之内。

Effect of Formalin Treatment on the Monogenean Pseudorhabdosynochus epinepheli (Monogenea) and the Fish Epinephelus coioides

Prophylactic methods against Pseudorhabdosynochus epinepheli (Monogenea) infection on the fish Epinephelus coioides were investigated in April 2000.The effect of formalin in seawater on P.epinepheli was that the semi-lethal concentration is 250×10-6 for 25 min,and 50×10-6 for 50 min.The effect of formalin in freshwater on P.epinepheli is reported as:the semi-lethal concentration was 83×10-6 for 3 min.The semi-lethal time for freshwater alone was 21 min.The toxicity of formalin in seawater to E.coioides was assessed:the semi-anaesthetic concentration was 940×10-6 in 30 min and 645×10-6 in 45 min.The toxicity of formalin in freshwater to E.coioides was as follows:the semi-anaesthetic concentration was 1 300×10-6 in 5 min and 500×10-6 in 10 min.The semi-lethal formalin concentration to E.coioides in seawater was between 600×10-6 and 1 000×10-6,and in freshwater was between 250×10-6 and 500×10-6.The semi-anaesthetic and semi-lethal time of E.coioides in freshwater were 95 min and 115 min respectively.These results demonstrated that the lethal formalin concentrations for P.epinepheli in both seawater and freshwater fell in a safe range for E.coioides.