First record of facultative parasitism of Chilodonella uncinata based on goldfish (Carassius auratus) infection model

Cultivation of fish ciliate parasites: Progress and prospects

“…During in vitro culture, it was found that C. uncinata preferred to distribute densely on the surface of the medium and fed on the bacteria in the in vitro culture plate. The generation time was about 2.5 h during continuous 24 h microscopic observation and the optimal temperature for cultivation was 24–26°C 64 . Under extreme temperatures of 4 and 38°C, C. uncinata could survive for about 3 days and 2 weeks, respectively, but died within a day at 39°C (unpublished).…”

“…Besides, C. uncinata has also been reported as a facultative parasite of fish, 53,64 although it is commonly regarded as a free‐living species and had been used as an experimental organism in many genetic studies 57,65–68 . It was confirmed to be infective to goldfish and can cause the same tissue damage as other Chilodonella species 64 …”

“…Recently, a successful C. uncinata infection model was established 64 . In this model, goldfish (body length: 4.9 ± 0.4 cm) were used as the experimental fish.…”

“…Ten grammes of fresh wheat grains were added to 250 ml ddH 2 O and then sterilised to be prepared as the culture medium. Single ciliate cells in good condition (high motility and large in size) were placed into the medium to be cultured in the dark at 25°C 64 …”

“…Within this group, two main pathogenic species, Chilodonella hexasticha and C. piscicola, are considered quite dangerous as they can infect a wide range of wild and farmed freshwater fish species worldwide. 2,[60][61][62][63] Besides, C. uncinata has also been reported as a facultative parasite of fish, 53,64 although it is commonly regarded as a free-living species and had been used as an experimental organism in many genetic studies. 57,[65][66][67][68] It was confirmed to be infective to goldfish and can cause the same tissue damage as other Chilodonella species.…”