TWENTY-FOURTH ANNUAL EASTERN FISH HEALTH WORKSHOP Royal Pavilion Resort, Atlantic Beach, NC MARCH 9-11, 1999 Golden Shiner Virus-Like Isolates From Atypical Epizootics Occurring In Cool Water Luke R. Iwanowicz and Andrew E. Goodwin Aquaculture/Fisheries Center, University of Arkansas Pine Bluff, 1200 N. University Dr., P.O. Box 4912, Pine Bluff, AR 71611 Golden shiner virus (GSV), a pathogen of golden shiners (Notemigonus crysoleucas), was first described by Plumb et al. in 1979 (J. Fish. Res. Board Can. 36: 1390-1394). Original accounts of fish losses attributed to GSV describe a condition occurring in Arkansas during the late summer months when water temperatures were between 27 and 32ºC. Clinical signs of the disease included petechial hemorrhages in the eyes, dorsal musculature, visceral fat and intestinal mucosa in addition to a reddish translucent saddle anterior to the dorsal fin. Behavioral changes such as listless swimming at the water surface or in spiral patterns has also been observed in affected fish. The condition has only been documented in large golden shiners and results in low mortality. In the past two years relatively high chronic mortalities have been observed in shiner ponds during cooler months when water temperatures were as low as 15ºC. Clinical signs including petechia in the eyes, swimming in spirals, and small superficial patches of fungus were also observed. No parasitic or bacterial pathogens were isolated; however, a homogenate of viscera cultured on epithelial papilloma of carp (EPC) cells incubated at 20ºC produced a cytopathic effect (CPE) of syncytia and rounding of cells. Similar CPE occurs in fathead minnow (FHM), channel catfish ovary (CCO), brown bullhead (BB), Chinook salmon embryo (CHSE-214) and rainbow trout ovary (RTG-2) cell lines. A CPE was observed in EPC cells at 15 - 35ºC, but not at 4ºC. Biochemical properties of the isolates, including resistance to heat (50ºC for 30 min), chloroform (50%), ether (20%), 5-iodo-2 deoxyuridine (IDU), and pH 3 and 10 were consistent to those of GSV. The cell lines in which this virus produces CPE differ from those reported for GSV but, in our hands, cell line specificity of the type strain of GSV (ATCC VR957 Lot 1) was identical to our isolates. Golden shiners, fathead minnows (Pimephales promelas), goldfish (Carassius auratus), and rainbow trout (Oncorhynchus mykiss) were challenged by i.p. injection with the new isolate and maintained for 35 days at 16-18ºC. At the end of the challenge period, golden shiners appeared healthy but re-isolation of the virus was achieved from pooled samples. Virus was not re-isolated from the other fish species tested. Further examination of the virus will include treatment with RNase A and an electrophoretic comparison of the viral capsid proteins and genome with that of GSV. Return to 24th Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page