Epidemiology and identification of two species of Chilodonella affecting farmed fishes in China.

•Chilodonellosis in china is caused by C. hexasticha and C. piscicola.•Different species have been found in fish farms at different water temperatures.•Morphology is a valid criterion but overlapping ranges could cause misidentifications.•Genetic differences are clear and reliable between C. hexasticha and C. piscicola.