''Monostroma'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of marine

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

(

seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...

) in the family

Monostromataceae Monostromataceae is a family of green algae in the order Ulotrichales Ulotrichales is an order of green algae in the class Ulvophyceae.See the NCBIbr>webpage on Ulotrichales Data extracted from the Genera unplaced to family (''incertae s ...

. As the name suggests, algae of this genus are monostromatic (single cell layered). ''

Monostroma kuroshiense ''Monostroma kuroshiense'', a green alga in the division Chlorophyta, is a green seaweed endemic to Kuroshio Coast of Japan. This high-value seaweed is called Hitoegusa or Hirohano hitoegusa (ヒロハノヒトエグサ) in Japanese. Previously ...

'', an algae of this genus, is commercially cultivated in

East Asia East Asia is the eastern region of Asia, which is defined in both geographical and ethno-cultural terms. The modern states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. China, North Korea, South Korea and ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

for the edible product "hitoegusa-nori" or "hirohano-hitoegusa nori", popular

sushi is a Japanese cuisine, Japanese dish of prepared , usually with some sugar and salt, accompanied by a variety of , such as seafood, often raw, and vegetables. Styles of sushi and its presentation vary widely, but the one key ingredient is " ...

wraps. ''Monostroma''

oligosaccharides An oligosaccharide (/ˌɑlɪgoʊˈsækəˌɹaɪd/; from the Greek ὀλίγος ''olígos'', "a few", and σάκχαρ ''sácchar'', "sugar") is a saccharide polymer containing a small number (typically two to ten) of monosaccharides (simple sugar ...

with

degree of polymerization The degree of polymerization, or DP, is the number of monomeric units in a macromolecule or polymer or oligomer molecule. For a homopolymer, there is only one type of monomeric unit and the ''number-average'' degree of polymerization is given by ...

6 prepared by

agarase Agarase (, ''AgaA'', ''AgaB'', ''endo-beta-agarase'', ''agarose 3-glycanohydrolase'') is an enzyme with List of enzymes, systematic name ''agarose 4-glycanohydrolase''. It is found in agarolytic bacteria and is the first enzyme in the agar cataboli ...

digestion from ''Monostroma nitidum''

polysaccharides Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with w ...

have been shown to be an effective prophylactic agent during ''

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...

'' and ''

in vivo Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and ...

'' tests against

Japanese encephalitis Japanese encephalitis (JE) is an infection of the brain caused by the Japanese encephalitis virus (JEV). While most infections result in little or no symptoms, occasional inflammation of the brain occurs. In these cases, symptoms may include he ...

viral infection. The sulfated oligosaccharides from ''Monostroma'' seem to be promising candidates for further development as antiviral agents. The genus ''Monostroma'' is the most widely cultivated genus among green

Classification

Species-level classification within this genus is quite problematic and no consensus exists among algal taxonomists. This genus is oftentimes referred as "''Gayralia''", however ''Gayralia'' and ''Monostroma'' are congeneric. A number of monostromatic algal species have been removed from this genus, including Kornmannia, Ulvopsis and Capsosiphon. Currently accepted working-classification of monostromatic green algae is provided as a figure. A taxonomic field-identification dichotomous key for this genus is available

Genetics

Largest phylogeographic assessment of this genus yet conducted in SW

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

revealed existence of

sympatric speciation Sympatric speciation is the evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region. In evolutionary biology and biogeography, sympatric and sympatry are terms referring to organi ...

in a

panmictic Panmixia (or panmixis) means random mating. A panmictic population is one where all individuals are potential partners. This assumes that there are no mating restrictions, neither genetic nor behavioural, upon the population and that therefore all ...

population; the first report of sympatric speciation in algae

Ecophysiology, cultivation and life cycle

A number of peer-reviewed scientific literature exists on the ecophysiology of this algal genus. Natural and cultivated sexually reproducing environmental samples, as well as sexually reproducing and serendipitously discovered asexually reproducing

ecotype In evolutionary ecology, an ecotype,Greek: ''οίκος'' = home and ''τύπος'' = type, coined by Göte Turesson in 1922 sometimes called ecospecies, describes a genetically distinct geographic variety, population, or race within a species, ...

s of monostromatic green alga from

Tosa Bay Tosa Bay () is a bay north of the line connecting Cape Muroto and Cape Ashizuri in Kochi Prefecture, Japan. Tosa Bay is better fishing grounds in Japan, which is strongly affected by the Kuroshio Current The , also known as the Black or or t ...

, Japan are conspecific (belong to the same species). Patterns of seasonal fluctuations in its thallus lengths were

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

specific and recur annually. Both appearance and decay of thalli were earlier at high saline habitats, suggesting that salinity positively influences either maturation of

sporophyte A sporophyte () is the diploid multicellular stage in the life cycle of a plant or alga which produces asexual spores. This stage alternates with a multicellular haploid gametophyte phase. Life cycle The sporophyte develops from the zygote pr ...

s or senescence of

gametophyte A gametophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has on ...

s. Results from life cycle, thallus ontogeny, gametangial ontogeny and phylogenetic analyses suggest that this algal genus is evolutionarily affiliated in the order Ulotrichales. Type of life cycle is not a valid diagnostic character for the species circumscription in Monostromataceae

Reproduction and sex-ratio

Gametogenesis Gametogenesis is a biological process by which diploid or haploid precursor cells undergo cell division and differentiation to form mature haploid gametes. Depending on the biological life cycle of the organism, gametogenesis occurs by meiotic d ...

in this alga occurs in discontinuous patches along the frontal apex and the

gametes A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce t ...

release synchronously in a posterior faced linear fashion by the dehiscence of gametangial sheath, leading to the thallic disintegration. The overall primary

sex ratio The sex ratio (or gender ratio) is usually defined as the ratio of males to females in a population. As explained by Fisher's principle, for evolutionary reasons this is typically about 1:1 in species which reproduce sexually. Many species devia ...

of this alga is about 1:1 which is likely to reflect Fisherian selection.Bast, F., Hiraoka, M., & Okuda, K. 2009. Spatiotemporal Sex Ratios of a Dioecious Marine Green Alga: Monostroma latissimum (Kützing) Wittrock. International Journal on Algae., 11: 141-150.

Culinary use

In Korea, edible ''Monostroma'' species such as ''Monostroma nitidum'' are called ''

parae Green laver (), known as ''aonori'' (; ) in Japan, ''sea cabbage'' () or ''hutai'' () in China, and ''parae'' () in Korean, is a type of edible green seaweed, including species from the genera ''Monostroma'' and ''Ulva'' ('' Ulva prolifera'', ' ...

'' (), and eaten as a ''

namul Namul ( ko, 나물) refers to either a variety of edible grass or leaves or seasoned herbal dishes made of them. Wild greens are called ''san-namul'' (, "mountain namul"), and spring vegetables are called ''bom-namul'' (, "spring namul"). On t ...

'' vegetable. In Japan, dried ''

'' called

aonori Green laver (), known as ''aonori'' (; ) in Japan, ''sea cabbage'' () or ''hutai'' () in China, and ''parae'' () in Korean, is a type of edible green seaweed, including species from the genera ''Monostroma'' and ''Ulva'' ('' Ulva prolifera'', ' ...

is used to season dishes such as

takoyaki is a ball-shaped Japanese snack made of a wheat flour-based batter and cooked in a special molded pan. It is typically filled with minced or diced octopus An octopus ( : octopuses or octopodes, see below for variants) is a soft-bod ...

and

okonomiyaki is a Japanese savory pancake dish consisting of wheat flour batter and other ingredients (mixed, or as toppings) cooked on a '' teppan'' (flat griddle). Common additions include cabbage, meat, and seafood, and toppings include ''okonomiyaki' ...

. In

Okinawa is a prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 km2 (880 sq mi). Naha is the capital and largest city ...

, it is used in a soup called āsa nu ushiru.

References

External links

{{Taxonbar, from=Q3321261 Ulvophyceae genera Ulotrichales