Susceptibility of pike-perch Sander lucioperca to a panel of ranavirus isolates

The host range of ranaviruses was investigated by challenging pike-perch (Sander lucioperca) with the following ranavirus isolates: epizootic haematopoietic necrosis virus (EHNV), European sheatfish virus (ESV). European catfish virus (ECV), pike-perch iridovirus (PPIV), short-finned eel virus (SERV) and frog virus 3 (FV3). Pike-perch fry were bath-challenged at 12 C and 22 C at 5 weeks post hatching, and the challenge was repeated with EHNV and PPIV in older fish (15 weeks post hatching) at higher densities. A third batch of fish was subjected to intraperitoneal (i.p.) and cohabitation challenge with EHNV, ESV, ECV and PPIV at 16 C. Statistically significant mortality was observed in EHNV-challenged fish at both temperatures in the five week old fish. No mortalities were seen in older fish challenged with EHNV and PPIV. High mortalities were registered in i.p.-challenged fish, but not in cohabitated fish. Virus re-isolation was possible from the youngest bath-challenged fish in all challenge trials and the i.p.-challenged fish, but not from older fish or cohabitated fish. Susceptibility of pike-perch to ranaviruses appears to be dependent on age of fish and challenge route. The study shows that pike-perch are susceptible to infection with ranavirus under certain conditions, and it is suggested that this be considered when reviewing the legislation on notifiable diseases. (C) 2011 Elsevier B.V. All rights reserved.