Size-Related Susceptibility of Salmonids to Two Strains of Infectious Hematopoietic Necrosis Virus
- 1 January 1990
- journal article
- research article
- Published by Oxford University Press (OUP) in Transactions of the American Fisheries Society
- Vol. 119 (1) , 25-30
- https://doi.org/10.1577/1548-8659(1990)119<0025:ssostt>2.3.co;2
Abstract
Infectious hematopoietic necrosis is generally considered a disease of salmonid alevins, fry, and early juveniles. It has been suggested that this disease kills only young salmonids and that susceptibility decreases with increased size and age of the fish. To determine if decreased susceptibility occurs with increasing size, we exposed four different sizes of rainbow trout Oncorhynchus mykiss (mean weight, 0.2–13.1 g) and kokanee (lacustrine sockeye salmon) Oncorhynchus nerka (0.2–7.2 g) to two waterborne strains of infectious hematopoietic necrosis virus. Both species were exposed to four concentrations of a type-1 virus strain, which was isolated from fish in Oregon, and a type-2 virus strain obtained from fish in Idaho. Neither strain of virus was consistently more virulent over all exposure concentrations for kokanee at the 0.2-g fish size, At all other sizes, kokanee were consistently more susceptible to the Oregon strain than to the Idaho strain (sign test, P < 0.002). Conversely, all sizes...This publication has 0 references indexed in Scilit: