Biologically Active Factors against the Monogenetic Trematode<i>Gyrodactylus stellatus</i>in the Serum and Mucus of Infected Juvenile English Soles

Length of survival of the monogenetic trematode Gyrodactylus stellatus in serum and mucus collected from English soles Pleuronectes vetulus at different stages of a laboratory epizootic suggests that both the mucus and serum may be involved in resistance to the parasite. In general, trematode survival was shorter in the serum and mucus samples collected from English soles at the later, recovering stages of infection. A rabbit antiserum against English sole whole serum was used in a gel diffusion immunoassay to show that mucus from infested English soles contained proteins antigenically similar to English sole serum proteins. Precipitation reactions appeared strongest in mucus collected during later stages of infection. No precipitation reactions were detected in the mucus of uninfested fish, indicating that the precipitation bands that were observed were associated with G. stellatus infections.