Intracellular parasites of unknown taxonomic position in gills of common carp Cyprinus carpio

Abstract

the gill filaments of common carp Cypnnus carpio f~ngerlings heavily infected with Sphaerospora molnan, intracellular parasites of unknown taxonomic position were detected with TEM. Cells, up to 3.5 pm in size, displayed surface projections which were often micro\fillous in shape One or more nuclei often in diplokaryon arrangement were seen in sectioned cells. Except for numerous dense bodies, no cytoplasmic organelles were observed. The possible relation to amphizoic amoebae, haplosporidia, rnicrosporidia and myxosporean stages is discussed; these parasites could not be identified with any of the them.