Gracilaria, also known as irish moss or ogonori, is a genus of red algae in the family Gracilariaceae. It is notable for its economic importance as an agarophyte meaning that it is used to make agar, as well as its use as a food for humans and various species of shellfish. Various species in the genus are cultivated among Asia, South America, Africa and Oceania. They produce over 90% of the world's agar.
Gelidium is a genus of thalloid red algae comprising 134 species. Its members are known by a number of common names.
Drachiella is a genus of marine red alga. It has scaly thickenings; also "rhizoids fringing openings". It is found below the kelp zone in areas exposed to moderate wave action; it is iridescent, and consists of a short, narrow stipe broadening into midribless thalli which reach 7 cm in length. Drachiella exhibits diffuse intercalary and marginal growth, and rhizoids are common along the margins, which it uses for anchorage. Pit connections often link adjoining cells.
Peyssonnelia is a genus of thalloid red alga, named after naturalist Jean-André Peyssonnel (1694–1759) It includes the algae commonly known as rumoi-iwanokawa, mayoi-iwanokawa and akase-iwanokawa. Specimens can reach around 20 cm in size. Peyssonnelia produces tetraspores.
The Rhodogorgonales are an order of red algae, a sister group to the corallines. They are always thalloid and calcified; their calcification is very different from the corallines, as individual calcite crystals are deposited in the cell wall of specialised cells; this suggests that the evolution of calcification may have been independent from the corallines. They have no fossil record.
Red algae, or Rhodophyta, are one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (class), and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats but relatively rare in freshwaters. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity.
Bangiales is an order of multicellular red algae of the class Bangiophyceae containing the families Bangiaceae, Granufilaceae, and possibly the extinct genus Rafatazmia with one species, Rafatazmia chitrakootensis. They are one of the oldest eukaryotic organisms, possibly dating back to 1.6 billion years old. Many species are used today as food in different cultures worldwide. Their sizes range from microscopic (Bangiomorpha) to up to two meters long. Many of its species are affected by Pythium porphyrae, a parasitic oomycete. Similar to many other species of red algae, they reproduce both asexually and sexually. They can be both filamentous or foliose, and are found worldwide.
Hypnea is a genus of red algae, and a well known carrageenophyte.
Batrachospermaceae is a family of fresh water red algae (Rhodophyta). Genera within the Batrachospermaceae generally have a "Lemanea-type" life history with carpospores germinating to produce chantransia. Sporophyte phase with meiosis occurs in an apical cell to produce the gametophyte stage. Pit connections have two pit plug cap layers with the other layer enlarged. This family of freshwater red algae is uniaxial, meaning each filament with a single apical cell. The genera included within Batrachospermaceae are listed in the table below.
Michael Dominic Richard Guiry, is an Irish botanist, who specialises in phycology (algae). See for example the articles. He is the founder and director of the algal database, AlgaeBase.
Gracilaria changii is an agarophytic red algae mostly found in mangroves. The nuclear and chloroplast genomes of G. changii have been sequenced.
The Gelidiellaceae is a small family of red algae containing 5 genera of agarophytes.
The Pterocladiaceae is a small family of red algae containing 2 genera of agarophytes.
The Pterocladiophilaceae is a small family of red algae containing 2 genera of thallus parasitic algae.
Naccariaceae is a family of red algae in the order Bonnemaisoniales, with 3 monotypic genera that are found in both the Pacific and Atlantic Oceans.
Scinaiaceae is a family of red algae (Rhodophyta) in the order Nemaliales.
Liagoraceae is a family of red algae (Rhodophyta) in the order Nemaliales. The type genus is LiagoraJ.V.Lamouroux.
Halymeniales is an order of red algae belonging to the class Florideophyceae and the subclass Rhodymeniophycidae.
Peyssonneliales is a monotypic order of red algae belonging to the class Florideophyceae and the subclass Rhodymeniophycidae. It contains only 1 known family, PeyssonneliaceaeDenizot, M., 1968.
