Colacosiphon: a new genus described for a mycoparasitic fungus

An undescribed heterobasidiomycetous fungus was found in cultures originati ng from bark beetles placed onto a natural medium. Spores were borne apical ly oil extraordinarily long, filiform, aseptate structures arising from swo llen hyphal cells. Within these cells, parasitic interactions with hyphae o f an unidentified ascomycete by colacosomes were found. The septal pores of the parasitic fungus were simple and associated with microbodies containin g inclusions similar to those of Woronin bodies. The fungus is closely rela ted to Cryptomycocolax abnormis, the single species of the hitherto monotyp ic order Cryptomycocolacales. The undescribed fungus differs from C. abnorm is by the presence of only one type of colacosome, the absence of clamps, a nd the absence of a transversely septate stage during sporogenesis. A new g enus and species is proposed for the undescribed fungus: Colacosiphon filif ormis. Since it is not clear whether the unusual sporogenous structures are conidiophores or basidia, the new taxon was preliminarily considered as an amorphic.