Cladophora

Cladophora is a genus of filamentous green algae in the family Cladophoraceae, within the order Cladophorales. Members are found in freshwater and marine environments worldwide and commonly form dense green mats or tufts on rocks, sediments, macrophytes, or other substrata. The thallus consists of branching, coenocytic filaments—long, multinucleate cells—with a simple, uniseriate organization and bright green chloroplasts.

Cladophora species thrive in nutrient-rich waters and are common in nearshore and littoral zones. They can rapidly proliferate during warm, calm periods, forming mats that alter light penetration and oxygen dynamics and may smother other organisms. Outbreaks are linked to eutrophication from agricultural runoff, sewage, and other nutrient inputs. In parts of the Great Lakes and other regions, summertime blooms have been persistent and challenging to manage. In marine environments, Cladophora can occur on rocky shores across temperate to subtropical regions.

Life cycle and reproduction: Reproduction is largely asexual through fragmentation of the thallus, which promotes rapid spread. Sexual reproduction has been described in some species but is less well understood.

Notable freshwater species include Cladophora glomerata, common in lakes and rivers, and marine forms such as Cladophora rupestris. The genus is widely studied in ecological contexts and can serve as a bioindicator of nutrient pollution due to its responsiveness to nitrogen and phosphorus.