DAO 52:185-190 (2002)  -  doi:10.3354/dao052185

Epizootic cutaneous papillomatosis in roach Rutilus rutilus: sex and size dependence, seasonal occurrence and between-population differences

Raine Kortet*, Anssi Vainikka, Jouni Taskinen

Department of Biological and Environmental Science, University of Jyväskylä, PO Box 35 (YAC341), 40351 Jyväskylä, Finland

ABSTRACT: Epidemiology of epidermal papillomatosis in roach Rutilus rutilus was studied in 11 roach populations in Finland in 1999 and 2000 during the spawning period. In addition, the seasonal pattern of the disease was described in 1 population. Papilloma tumours were observed on the skin and fins of roach in 8 populations out of 11. Prevalence of papillomatosis varied from 0 to 62%, being higher in populations subject to industrial or sewage effluents. Males and large fish had higher prevalence of papilloma tumours. The disease outbreak peaked during the spawning period and signs of recovered skin on fish were observed later during the year. The gender dependence in the disease prevalence found in the study may indicate differences in stress and immunocompetence between roach males and females during the spawning period.


KEY WORDS: Spawning papillomatosis · Roach · Tumours · Seasonality · Gender dependence · Pollution


Full text in pdf format