Conidium ontogeny in marine hyphomycetous fungi: Asteromyces cruciatus and Zalerion maritimum

Developmental and ultrastructural aspects of conidium and conidiogenous cell formation in two species of marine hyphomycetes, Asteromyces cruciatus and Zalerion maritimum, are described, and a discussion of their accomodation in the experimental classification of Fungi Imperfecti, which is based on developmental characters, is presented. The blastic, basipetal and whorled pattern of conidiogenesis in A. cruciatus is compared to diagrammatic interpretations of conidium and conidiogenous cell formation in other hyphomycetous fungi, including Tritirachium album, Nodulisporium hinnuleum, Botrytis cinerea and Cladobotryum variospermum. Helicoid conidium formation in z. maritimum is also described, and it is suggested that the characters of this distinctive mode of blastic ontogeny define a separate category in the experimental classification which would include a large number of developmentally-related species.