Zschokkella russelli Tripathi (Myxozoa: Myxosporea) from the five-bearded rockling, Ciliata mustela L., (Teleostei: Gadidae) in Wales

Abstract. Up to 88-9% of five-bearded rocklings, Ciliata mustela L., from three localities in Wales harboured the coelozoic myxozoan parasite Zschokkella russelli Tripathi. Previously recorded only from the gall-bladder of British rocklings, Z. russelli was also found to produce proliferation, enlargement and thickening of hepatic ducts, lowering of the duct epithelium and pericholangitis. Histological, scanning and transmission electron microscopy techniques were used to examine the parasite, and comparisons were drawn between Z. russelli from Welsh fish and infections recorded elsewhere, particularly from Plymouth, Devon.