Cumulative mortalities induced in trout by the various SDV. Twenty-five juvenile trout (mean weight, 3 g) were infected by intraperitoneal injection with 105 PFU/fish of rSDV, rSDVStructwt, rSDV-E2A8, or rSDV-E2T136 or were mock infected. Mortalities were recorded each day postinjection over a 2-month period. For statistical grouping, a comparison of survival between groups was performed with the log rank χ2 test on the Kaplan-Meier survival data using GraphPad Prism (GraphPad, San Diego, CA). Viruses that were assigned to statistically similar groups (and, thus, share a letter) are not significantly different from each other (P > 0.05), whereas those that were not assigned to statistically similar groups are significantly different (P < 0.01).