Temperature‐Associated Regression of Walleye Dermal Sarcoma Tumors

• Published in: Journal of aquatic animal health 2000-09, Vol.12 (3), p.189-195
• Main Authors: Getchell, R. G., Wooster, G. A., Bowser, P. R.
• Format: Article
• Language: English
• Subjects: Freshwater; Stizostedion vitreum vitreum
• ISSN: 0899-7659; 1548-8667
• DOI: 10.1577/1548-8667(2000)012<0189:TAROWD>2.0.CO;2

A temperature‐associated model for tumor regression was established using the virally induced walleye dermal sarcoma (WDS). In one trial, walleyes Stizostedion vitreum received a topical application of a cell‐free dermal sarcoma tumor filtrate and were allowed to develop grossly visible tumors at 15°C for 5 months. The walleyes were then randomly placed into one of three temperature treatment groups (10, 15, or 20°C) and grossly examined at monthly intervals for the presence of tumors. The rates of tumor regression (calculated as incidence densities) were compared across groups. The regression of WDS tumors was associated with increased temperature over the course of the 10‐month study. The incidence of tumor regression was significantly higher in walleyes held at 15 or 20°C than in those held at 10°C. In another trial (which more closely replicated the temperatures of Oneida Lake, New York, during the early spring, when WDS transmission is thought to occur), tumors were allowed to develop at 10°C for 1 month and then at 15°C for 5 months, before the temperature was increased to 20°C. In this trial, walleyes were tagged with transmitters so that they could be individually identified during the monthly survey of tumor status. Rates of regression observed were less than those in the first trial.