团头鲂累枝虫病的观察与防治研究

STUDIES ON EPISTYLIS DISEASE OF MEGALOBRAMA AMBLYCEPHALA AND ITS CONTROL

首次确诊该病是由累枝虫附生后引起细菌感染的累枝虫病；通过药物试验，得出甲醛防治团头纺累枝虫病的最低有效浓度为1．56×10－6，全池遍洒的安全浓度为25×10－6；设计出了一种网箱养鱼病害防治的施药新方法──PFUM法，从而使该病的治愈率达99％。

The systematic studies comprised the dingnosing Epistylis disease of Megalobramaamblycephala, Choosing effective medication and detecting its medical concentration, and designing a method of controlling the disease in this paper. The results were as follows: (1) The M.amblycephala with so-called Epistylis disease which was the first discovered in China, collectedfrom the net-box in Mongshan Reservoir in Nanchang of Jiangxi Province; Was submitted for studying the symptom and the infecting process. The infecting process was that, at first,Epistylis megalobramae sticked to the scales of M. amblycephala and destroyed the scales so thata large number of rod bacteria developed there and the fester appeared as a small red spot. Afterthat, the scales became putrefaction and fell off. Most of the erosions founded on the abdomen. Inserious cases, the ribs and viscera of diseased fish could be exposed and the diseased fish woulddie. The red spots and wounds in healthy M. amblyephala would appeared within five days following the fish cultivated with diseased fish in net-box; (2) E. megalobramae was immersed in100 ×10-6 of KMnO4, CH3COOH, CuSO4, C4H6O4Cl3P and HCHO solutions respectively fortesting its susceptibility to these medication. Among them, HCHO was the most effective to killE. megalobramae. The lowest effective concentration of HCHO to the Epistylis was 1. 5 ×10 -6;(3) The safety limit of HCHO to M. amblycephala was 200×10-6; (4) A new curingmethod, polyrethane Foam Unit with Medication (PFUM), was developed for controlling the disease.