南方鲶的三代虫病研究

南方鲶（Silurusmeridionalis）的三代虫病病原体是古雪夫三代虫（GyrodactylusgusseviLing，1962）．该虫离开南方鲶后，有粘液时，存活率比无粘液时高（32-83）％，存活时间也较无粘液时长（1．5-3.5）h．古雪夫三代虫可通过养带虫鱼的水及与病鱼直接接触传播．该三代虫最先感染南方鲶的部位是上颌须和臀鳍，其次是尾鳍和其它部位．南方鲶急三代虫病的早期症状是上颌须变软、变白和断须，通过这一特点，可进行该病的早期诊断．

Studies on Gyrodactyliasis of the Southern Catfish (Silurus meridionalis)

In the conditions of tests gyrodactyliasis of southern catfish (Silurus meridionalis) was studied.The conlusions can be drawn as follows: Gyrodactylus gussevi Ling,1962 was the parasite which caused gyrodactylicasis of the southern catfish.Survival rate and period of G.gussevi were much higher and longer in presence of mucus of the catfish than those in absence of mucus of this fish.G. gussevi could be transferred to uninfected southern catfish by placing them in the same tank with the infected catfish or inthe water in which the infected catfish was removed. One pair of maxillary barbels and anal fin of thecatfish were earliest infected by G. gussevi, then Caudal fin and other sites were. Maxillary barbelsprogressively getting white and Soft and finally broken at their some places were initial symptoms of thisdisease, as was a valuable aid in diagnosis in early stages of the gyrodactyliasis.