Observations on dilabifilum (Class chlorophyta, order chaetophorales sensustricto) and allied genera

Abstract

Clonal algal cultures isolated from a stream in south-west England and a lake in northern Denmark correspond to the little-known genus Dilabifilum. The developmental morphology and reproduction of these isolates were compared with cultures (often type cultures) of the three species of Dilabifilum species recognized by Tschermak-Woess. All our isolates closely corresponded with a previously described species, Dilabifilum printzii. Some of the vegetative traits traditionally used for defining species were found to be of questionable diagnostic value. The most useful traits proved to be the branching habit, degree of compactness of the filaments, length to breadth ratio of the cells, form of the cells, and physiological features (e.g. growth rate, readiness to become coccoidal). The genus remains ill-defined, with earlier observations concerning the production of quadriflagellate zoospores by the type culture of D. arthopyreniae still requiring reconfirmation. © 1990 Taylor & Francis Group, LLC.