Population dynamics of Carassius auratus ectoparasitic Trichodinella epizootica in Baiyangdian lake and treatment of trichodiniasis

Population dynamics of Trichodinella epizootica parasited on the gill of Carassius auratus were studied from April,2010 to October,2010.The result showed that T.epizootica could parasite on the gill of the fish when water temperature was from 15 ℃ to 30 ℃.The first prevalence peak of T.epizootica reached on May and the second(the highest prevalence in the year) peak reached on August.It indicated that the prevalences of T.epizootica in the spring and summer were higher and it showed obvious seasonality.Treatment of trichodina parasitized on Pseudorasbora parva was studied in a laboratory modulated experiment,using some Chinese traditional medicines i.e.Leiwan Binlang Powder,Baibu Guanzhong Powd,compound herbs Ⅰ and Ⅱ,Sophora,Artemisia annua and one chemical substance, mixture of copper sulfate and ferrous sulfate.It was effective after treated with Chinese traditional medicine,while these medicines acted slowly.Normally the antiparasitic efficacy was high after the fish had been treated continuously for 3-5 days.Mixture of copper sulfate and ferrous sulfate was effective even at low concentration,while the treated fish showed high mortality.The result is helpful for us to predict the occurrence of T.epizootica parasited on C.auratus in relation to the seasonality and take measures of prophylaxis and treatment consequently.It is also helpful to select the suitable medicine,dosage and time to control the occurrence of trichodiniasis.