The occurrence and distribution of Dermocystidium percae (Mesomycetozoea) in perch (Perca fluviatilis) in the lower Thames Valley,UK

The occurrence and microhabitat distribution of Dermocystidium percae on perch (Perca fluviatilis) was investigated in four sites in the lower Thames Valley, south‐east England. Fish were infected at all sites, with the highest prevalence occurring in a commercial fishery and the lowest in a large impounded water storage reservoir. The microhabitat distribution of D. percae cysts on the perch favoured the dorsal and anal fins, in contrast to previous studies, although a single occurrence on the gills was reported. The role of host stress on the prevalence of D. percae is discussed.