Brown algae are a large group of multicellular algae comprising the class Phaeophyceae. They include many seaweeds located in colder waters of the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar regions. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, Macrocystis, a kelp of the order Laminariales, may reach 60 m (200 ft) in length and forms prominent underwater kelp forests that contain a high level of biodiversity. Another example is Sargassum, which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Some members of the class, such as kelps, are used by humans as food.
Phloroglucinol is an organic compound with the formula C6H3(OH)3. It is a colorless solid. It is used in the synthesis of pharmaceuticals and explosives. Phloroglucinol is one of three isomeric benzenetriols. The other two isomers are hydroxyquinol (1,2,4-benzenetriol) and pyrogallol (1,2,3-benzenetriol). Phloroglucinol, and its benzenetriol isomers, are still defined as "phenols" according to the IUPAC official nomenclature rules of chemical compounds. Many such monophenolics are often termed polyphenols.
Dictyotales is a large order in the brown algae containing the single family Dictyotaceae. Members of this order generally prefer warmer waters than other brown algae, and are prevalent in tropical and subtropical waters thanks to their many chemical defenses to ward off grazers. They display an isomorphic haplodiploid life cycle and are characterized by vegetative growth through a single apical cell. One genus in this order, Padina, is the only calcareous member of the brown algae.
Pylaiella (mung) is a genus of seaweed that can be a nuisance due to its ability to coat people, ropes, animals, and more when it blooms close to the shore under particular conditions.
Colpomenia is a genus of brown macroalgae in the family Scytosiphonaceae.
Durvillaea is a genus of large brown algae in the monotypic family Durvillaeaceae. All members of the genus are found in the southern hemisphere, including Australia, New Zealand, South America, and various subantarctic islands. Durvillaea, commonly known as southern bull kelps, occur on rocky, wave-exposed shorelines and provide a habitat for numerous intertidal organisms. Many species exhibit a honeycomb-like structure in their fronds that provides buoyancy, which allows individuals detached from substrates to raft alive at sea, permitting dispersal for hundreds of days over thousands of kilometres. Durvillaea species have been used for clothing, tools and as a food source by many indigenous cultures throughout the South Pacific, and they continue to play a prominent role in Chilean cuisine.
Durvillaea antarctica, also known as cochayuyo and rimurapa, is a large, robust species of southern bull kelp found on the coasts of Chile, southern New Zealand, and Macquarie Island. D. antarctica, an alga, does not have air bladders, but floats due to a unique honeycomb structure within the alga's blades, which also helps the kelp avoid being damaged by the strong waves.
Durvillaea willana is a large species of southern bull kelp endemic to New Zealand.
Phlorotannins are a type of tannins found in brown algae such as kelps and rockweeds or sargassacean species, and in a lower amount also in some red algae. Contrary to hydrolysable or condensed tannins, these compounds are oligomers of phloroglucinol (polyphloroglucinols). As they are called tannins, they have the ability to precipitate proteins. It has been noticed that some phlorotannins have the ability to oxidize and form covalent bonds with some proteins. In contrast, under similar experimental conditions three types of terrestrial tannins apparently did not form covalent complexes with proteins.
Eckol is a phlorotannin isolated from brown algae in the family Lessoniaceae such as species in the genus Ecklonia such as E. cava or E. kurome or in the genus Eisenia such as Eisenia bicyclis.
Cystophora retroflexa is a brown alga species in the genus Cystophora. It found is found off the coasts of New Zealand and Australia. It is the type species of the genus. Prefers more sheltered environments compared to other Cystophora species, often found in sheltered reefs from 0 to 12 m in depth.
Silvetia is a genus of brown algae, commonly known as rockweed, found in the intertidal zone of rocky seashores of the Pacific Ocean. These were originally classified as members of the genus Pelvetia. In 1999, Silvetia sp. was created as a separate species from Pelvetia canaliculata due to differences of oogonium structure and of nucleic acid sequences of the rDNA. It was renamed in honor of Paul Silva, Curator of Algae at the Herbarium of the University of California, Berkeley. There are three species and one subspecies.
Lobophora is a genus of thalloid brown seaweed of the Phylum Ochrophyta; Class Phaeophyceae.
Colpomenia sinuosa, commonly named the oyster thief or sinuous ballweed, is a brown algae species in the genus Colpomenia. It is the type species of its genus and is widespread in tropical to temperate zones around the world.
Wendy Alison Nelson is a New Zealand marine scientist and world expert in phycology. She is New Zealand's leading authority on seaweeds. Nelson is particularly interested in the biosystematics of seaweeds/macroalgae of New Zealand, with research on floristics, evolution and phylogeny, as well as ecology, and life history studies of marine algae. Recently she has worked on the systematics and biology of red algae including coralline algae, distribution and diversity of seaweeds in harbours and soft sediment habitats, and seaweeds of the Ross Sea and Balleny Islands.
Dictyota is a genus of brown seaweed in the family Dictyotaceae. Species are predominantly found in tropical and subtropical seas, and are known to contain numerous chemicals (diterpenes) which have potential medicinal value. As at the end of 2017, some 237 different diterpenes had been identified from across the genus.
Cladostephus hirsutus is a marine brown alga.
Rosenvingea is a genus of brown algae first described by Frederik Børgesen in 1914.
Padina is a genus of brown macroalgae in the family Dictyotaceae.
Sphacelaria is a genus of brown macroalgae in the family Sphacelariaceae.
