Abstract
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 Branchiura sowerbyi. Other actinospores detected in B. sowerbyi, Tubifex tubifex and Limnodrilus hoffmeisteri 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 Zschokkella chezhachei from the bile duct of gibel carp available in GenBank, hereby inferring its life cycle. Phylogenetic analysis placed the aurantiactinomyxon type 1 within the Thelohanellus clade that parasitizes gibel carp and common carp. In contrast, aurantiactinomyxon type 3 and raabeia type 2 clustered within the Myxobolus clade associated with perciform and centrarchid fishes. Additionally, neoactinomyxon type 1 grouped with Thelohanellus wangi, a parasite of gill filaments in gibel carp, while raabeia type 1 clustered with Myxobolus cultus, found in the gill filaments of gibel carp and gold fish. This study represents the first report of the actinospore stage of T. wangi in Hungary, and the second report of the actinospore stage of M. cultus.