Water Net

The water net (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. The name water net comes from the mesh structure of their colonies, which can extend several decimeters; the scientific name also means "water net" in Greek.

Hydrodictyon consists of colonies of cylindrical cells that are joined end-to-end to form a net-like structure. The cells usually form pentagonal or hexagonal subgroups. Cells contain a parietal chloroplast with many small pyrenoids.