Protozoan parasites of carp (Cyprinus carpio L.): a comparative study of their occurrence in Bulgaria and Czechoslovakia, with the description of Trichodina perforata sp.N.

In the course of a long-term study of protozoan parasites of carp (Cyprinus carpio L.), a total of 27 protozoan species were discovered in Czechoslovakia and 26 species on the Bulgarian territory. Their list is supplemented with remarks on their pathogenicity, frequency of occurrence and morphology. There is no essential difference in the constituents of protozoan parasitofauna of carp between the two territories studied; a very similar fauna of protozoans can be anticipated on carp in other European regions. A new species, Trichodina perforata sp.n. is described from carps on Bulgarian territory; it is absent in Czechoslovakia. It is characterized by very thin, obliquely set thorns of denticles and by perforations in denticel blades. Throughout the area of the present distribution of the carp, records of its protozoan parasites include a total of 76 determined species, 6 parasites determined only to the generic level and 8 facultatively parasitic ciliates. Attention is drawn to several pathogenic species, which constitute a potential threat to carpiculture in Europe.