The water net with its genus Hydrodictyon is a taxon of freshwater green algae in the family Hydrodictyaceae. Hydrodictyon does well in clean, eutrophic water, and has become a nuisance in New Zealand, where it has been recently introduced.
It can reproduce asexually or sexually. Asexual reproduction takes place by biflagellated (having two flagella) zoospores formed by the thousands inside a cell. However, the zoospores hardly move, as they are packed very densely.
During sexual reproduction, which takes place by iso-gametes, that escape through a hole in the cell wall of the mother cell. Two gametes fuse, forming a zygote, which then develops a thick cell wall and becomes angular in shape.

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