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.
Hormosira is a genus of seaweed in the family Hormosiraceae. It is monotypic, with a single species, Hormosira banksii, also known as Neptune's necklace, Neptune's pearls, sea grapes, or bubbleweed it is native to Australia and New Zealand.
Coralline algae are red algae in the order Corallinales. They are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls. The colors of these algae are most typically pink, or some other shade of red, but some species can be purple, yellow, blue, white, or gray-green. Coralline algae play an important role in the ecology of coral reefs. Sea urchins, parrot fish, and limpets and chitons feed on coralline algae. In the temperate Mediterranean Sea, coralline algae are the main builders of a typical algal reef, the Coralligène ("coralligenous"). Many are typically encrusting and rock-like, found in marine waters all over the world. Only one species lives in freshwater. Unattached specimens may form relatively smooth compact balls to warty or fruticose thalli.
Halimeda is a genus of green macroalgae. The algal body (thallus) is composed of calcified green segments. Calcium carbonate is deposited in its tissues, making it inedible to most herbivores. However one species, Halimeda tuna, was described as pleasant to eat with oil, vinegar, and salt.
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.
Postelsia palmaeformis, also known as the sea palm or palm seaweed, is a species of kelp and classified within brown algae. It is the only known species in the genus Postelsia. The sea palm is found along the western coast of North America, on rocky shores with constant waves. It is one of the few algae that can survive and remain erect out of the water; in fact, it spends most of its life cycle exposed to the air. It is an annual, and edible, though harvesting of the alga is discouraged due to the species' sensitivity to overharvesting.
Padina pavonica, commonly known as the peacock's tail, is a small brown alga found in the Indian Ocean, the Pacific Ocean, the Atlantic Ocean and the Mediterranean Sea. It inhabits pools in the littoral zone typically with clayey, silty or sandy sediments. Other habitats include rocks and shell fragments in the shallow sublittoral, seagrass meadows, mangrove roots and coral reefs on tidal flats.
Turbinaria is a genus of brown algae (Phaeophyceae) found primarily in tropical marine waters. It generally grows on rocky substrates. In tropical Turbinaria species that are often preferentially consumed by herbivorous fishes and echinoids, there is a relatively low level of phenolics and tannins.
Acetabularia caliculus, the umbrella alga, is a species of green alga found in shallow temperate and tropical seas. It usually grows on pebbles, shells or pieces of rock, and is often found in seagrass meadows, on mudflats and coral reefs, in estuaries and growing on the submerged roots of mangroves. Each individual thallus consists of a single cell with a long stipe and a terminal cup-shaped or flattened disc.
Halodule uninervis is a species of seagrass in the family Cymodoceaceae. It is native to the western Pacific and Indian Oceans. Common names include narrowleaf seagrass in English and a'shab bahriya in Arabic.
Lobophora variegata is a species of small thalloid brown alga which grows intertidally or in shallow water in tropical and warm temperate seas. It has three basic forms, being sometimes ruffled, sometimes reclining and sometimes encrusting, and each form is typically found in a different habitat. This seaweed occurs worldwide. It is the type species of the genus Lobophora, the type locality being the Antilles in the West Indies.
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.
Mastocarpus papillatus, sometimes called Turkish washcloth, black tar spot, or grapestone is a species of red algae in the family Phyllophoraceae. It is sometimes confused with the distantly related Turkish towel which is of a similar texture but larger. The specific epithet papillatus is due to the nipple-like projections on the female gametophyte which can give the texture of a terrycloth washcloth found at a Turkish bath.
Padina boergesenii, commonly known as the leafy rolled-blade alga, is a species of small brown alga found in the tropical and subtropical western Atlantic Ocean, the Mediterranean Sea, and the Pacific Ocean. This seaweed was named in honour of the Danish botanist and phycologist Frederik Børgesen.
Padina japonica is a species of small brown alga found in the tropical and subtropical Indo-Pacific region.
Codium edule is a green alga common on shallow reef flats from the intertidal to the subtidal in tropical waters of the Indo-Pacific. The species is common in Hawaiʻi where it is usually called wāwaeʻiole and considered an edible alga or limu. Prominent ethnobotanist Isabella Abbott described its usage in her writing.
Padina is a genus of brown macroalgae in the family Dictyotaceae.
Thylacodes variabilis is a species of worm snail common in the rocky intertidal in Hawaiʻi and the tropical Pacific.
