Ectocarpus is a genus of filamentous brown alga that includes a model organism for the genomics of multicellularity.

[1][2] Among possible model organisms in the brown algae, Ectocarpus was selected for the relatively small size of its mature thallus and the speed with which it completes its life cycle.

[3][4] Tools available for Ectocarpus as a model species include a high quality genome sequence[5] and both forward[6] and reverse genetic[7] methodologies, the latter based on CRISPR-Cas9.

[11] Ectocarpus can be found across the globe, in temperate shorelines growing as epiphytes on other flora (e.g. seagrass, other alga) or on rocky substrates (epilithic).

[15] Ectocarpus thalli tend to shelter several marine invertebrates (e.g. crustaceans and nematodes) and some protists.

[18] In the laboratory, the life history is an isomorphic to slightly heteromorphic alternation of generations, but asexual strains also exist.

[19] Deployment of the sporophyte developmental program requires two TALE homeodomain transcription factors, OUROBOROS and SAMSARA.

Standard laboratory conditions are growth at 13 degrees Celsius under a 12h:12h light:dark cycle with irradiance at 20 μmol photons m−2 s−1.

[22] These enzymes may be part of the defence mechanism of Ectocarpus against halogenated defenses of brown algal hosts when growing as an epiphyte.

[23] Ectocarpus is vulnerable to an array of pathogens and parasites and is also sensitive to abiotic stresses such as shifts in temperature, light and salinity.

[24] Some currently accepted species of Ectocarpus include: Bourdareau, Simon; Tirichine, Leila; Lombard, Bérangère; Loew, Damarys; Scornet, Delphine; Wu, Yue; Coelho, Susana M.; Cock, J.

Tarver, James E.; Cormier, Alexandre; Pinzón, Natalia; Taylor, Richard S.; Carré, Wilfrid; Strittmatter, Martina; Seitz, Hervé; Coelho, Susana M.; Cock, J.

"The genome-scale metabolic network of Ectocarpus siliculosus (EctoGEM): a resource to study brown algal physiology and beyond".