Monterey Bay Aquarium Research Institute
Marine Botany

Life History

The Birds and the Bees and the Algae

Cladophora Main Page    Life History     Ecology     Culture       References



Most marine Cladophora can reproduce both sexually and asexually, and demonstrate a diplohaplontic life history. As with most of the Cladophoraceae, an alternation of generations between isomorphic diploid sporophyte and haploid gametophyte forms occurs, and may be seasonally segregated, at least in some regions studied. Environmental factors like temperature, vitamin limitations, and light fluctuations have been linked to promoting zoosporogenesis in freshwater species, but the ecological reproductive cues for marine Cladophora have thus far not been adequately studied.

In addition, parthenogenesis has been noted in some species, and most Cladophora seem to be perennial, though admittedly not much research has been completed on the reproduction and propagation of the genus in general.

Steps in the Life Cycle

  1. Quadriflagellate zoospores (1N) form in ordinary vegetative cells of the sporophyte individual (2N), break through the sides of the cells and enter the water
  2. Spores settle on substrate and germinate into diecious gametophytes (1N)
  3. Gametophytes form biflagellate isogamous gametes (1N), which burst from lateral apertures in branches of gametangia
  4. Gametes fuse externally forming quadriflagellate zygote (2N)
  5. Zygote settles and germinates directly into Sporophyte (2N)
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