Hungactinomyxon, a new actinosporean type and collective group(Myxozoa) from Branchiura sowerbyi Beddard (Oligochaeta).

Actinosporeans are characterised by great morphological diversity. As it has been proved that the class Actinosporea is a synonym of the Myxosporea, actinosporean genera have only been regarded only as actinosporean collective groups. While most actinosporeans are released individually by their oligochaete hosts, members of the synactinomyxon, siedleckiella and antonactinomyxon collective groups are released as eight connected structural elements. These actinosporean types are differentiated by the type of unit and junction of the caudal processes. On the basis of these characteristics, a new actinosporean type, constructed from eight echinactinomyxon units, is described as hungactinomyxon. Adjacent units are joined by two of their three processes and form two interconnected cubes, each containing four echinactinomyxons. Molecular biological studies also suggest that this new actinosporean type differs from other actinosporean types built up from eight structural elements for which 18S rDNA sequences are available in GenBank.