A seasonal prevalence study
of proliferative skin lesions was conducted on walleyes found
in Oneida Lake in 1986. Fish were examined during the spring
spawning activities at the New York State Department of Environmental
Conservation Oneida Fish Hatchery, Oneida Lake, Constantia, New
York in April. Through the remainder of the season, samples were
collected with the assistance of the staff of the Cornell University
Biological Field Station, Oneida Lake, Bridgeport, New York.
Oneida Lake walleyes were examined during the ice-free period
of the year. Prevalence data for four different skin lesions
were collected. Two of these lesions has proposed retroviral
etiologies at the time: walleye dermal sarcoma and discrete epidermal
hyperplasia. One lesion, diffuse epidermal hyperplasia, had a
proposed herpesvirus etiology. Lymphocystis (a cell hypertrophy),
the fourth lesions has an iridovirus etiology.
Prevalence of all lesions was
found to be high in the spring, low in the summer and high in
the fall. In addition, the tumors appeared to be rare on the
youngest fish, based on size of fish on which lesions were found.
Walleyes do not join the spawning run until they are approximately
3+ years-old. No lesions were observed on fish less than 300
mm total length. The relationship of age of fish to presence
of lesions was further investigated in later years when prevalence
of lesions by year class was investigated.
Reference:
Bowser, P.R., M.J. Wolfe, J.L. Forney, and G.A. Wooster.
1988. Seasonal prevalence of skin tumors from walleye (Stizostedionvitreum) from Oneida Lake, New York. J. Wildl. Dis. 24:292-298.
