Prevalence of Walleye Dermal Sarcoma by Age-Class in Walleyes from Oneida Lake, New York

Abstract

Walleye dermal sarcoma is a seasonally limited neoplasm caused by a retrovirus. The in-lake transmission patterns of this disease are unknown. We followed the prevalence of visible neoplasms among walleyes Stizostedion vitreum aged 3–8+ years from 1995 to 1999 in Oneida Lake, New York. The percentage of fish developing tumors increased from age 3 to age 6 but decreased thereafter. These findings give further support to the hypothesis that walleyes from Oneida Lake contract the disease during the spawning run and develop visible neoplasms in the fall and winter of that same year but return in the spring with regressing tumors that disappear by summer and do not return. Over time, almost all walleyes of a year-class may contract the disease. These findings are not consistent with the hypothesis that walleyes that have visible neoplasms in the spring will develop the disease again the following year.