Infections with gill parasitic monogeneans Thaparocleidus siamensis and T. caecus in cultured Catfish Pangasius hypophthalmus in Southern Vietnam.

摘要

Catfish culture in Vietnam has become an increasingly important economical factor. The most important domesticated species in Vietnam is Pangasius hypophthalmus also called "TRA". The production of this species is likely to increase during the next years following investment in improved culture. One factor needed to support this aquacultural development is the control of infectious diseases caused by parasites, bacteria and viruses. In order to facilitate the parasite control in catfish enterprises we have conducted a survey of catfish farms in two provinces of Southern Vietnam. A total of 351 specimens were collected in freshwater ponds from April to October 2006. The fish were caught by hand nets and transported to the laboratory in aerated freshwater and subjected to thorough investigation for gill parasites. Two species of Thaparocleidus were found. T. siamensis reached prevalences of 57% and intensities of up to 148 parasites per host. T. caecus was also present but in very low prevalences and intensities. The variations of these monogenean parasites in relation to season, host age and management factors are presented.