The life history and sexual reproduction ofColpomenia peregrina(Scytosiphonaceae, Phaeophyta) in Australia

Abstract

Although Colpomenia peregrina (Sauvageau) Hamel reproduces throughout most of the year in Australia, functional gametophytes are extremely rare. Gametophytes occur in late winter, they are dioecious and reproduction is anisogamous. The zygotes, female gametes, and the majority of male gametes develop into filamentous sporophytes bearing unilocular sporangia. Zoospores from the sporophyte generations mostly give rise to saccate C. peregrina. Cultured strains derived from wild C. peregrina differ in their reproductive potential. Sporophyte generations were only found in strains derived from parthenogametes or zygotes. Several other strains produced saccate progeny, irrespective of the culture conditions. The evidence that such strains may be asexually reproducing, “morphological” gametophytes is discussed.