Derived from tissue posterior to the anus of normal adult minnows. Reported to be capable of growth over a wide temperature range from 4°C-36°C with maximum growth at 34°C. Support growth of the virus of infectious pancreatic necrosis (IPN), cat fish tumour virus (CTV) and Granoff frog virus (FV1). ECHO-II will multiply in FHM but the cytopathic effect is not extensive.