Actinosporean diversity in a Hungarian fish farm and description of the life cycle of .

Six distinct actinospore types were identified in the intestinal epithelium of three oligochaete species collected from a fish farm in Ócsárd, in Hungary. Among these, two new types: aurantiactinomyxon type 1 and aurantiactinomyxon type 2 were described both morphologically and molecularly from . Other actinospores detected in , and have been known previously in literature. Three myxosporean life cycles were inferred through molecular analysis, including a newly described one. Analysis of 18S ribosomal DNA (rDNA) revealed that aurantiactinomyxon type 2 matched the sequence of from the bile duct of gibel carp available in GenBank, hereby inferring its life cycle. Phylogenetic analysis placed the aurantiactinomyxon type 1 within the clade that parasitizes gibel carp and common carp. In contrast, aurantiactinomyxon type 3 and raabeia type 2 clustered within the clade associated with perciform and centrarchid fishes. Additionally, neoactinomyxon type 1 grouped with , a parasite of gill filaments in gibel carp, while raabeia type 1 clustered with , found in the gill filaments of gibel carp and gold fish. This study represents the first report of the actinospore stage of in Hungary, and the second report of the actinospore stage of .