''Pyropia'' is a genus of

red algae Red algae, or Rhodophyta (, ; ), make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest Phylum, phyla of algae, containing over 7,000 recognized species within over 900 Genus, genera amidst ongoing taxon ...

in the family Bangiaceae. It is found around the world in intertidal zones and shallow water. The genus has folding frond-like blades which are either red, brown or green. Some ''Pyropia'' species are used to create

nori Nori is a dried edible seaweed used in Japanese cuisine, usually made from species of the red algae genus ''Pyropia'', including ''P. yezoensis'' and ''Pyropia tenera, P. tenera''. It has a strong and distinctive flavor, and is generally made in ...

, and are thus important subjects for aquaculture.

Taxonomy

''Pyropia'' was originally erected by Jacob Georg Agardh, a botanist and professor at

Lund University Lund University () is a Public university, public research university in Sweden and one of Northern Europe's oldest universities. The university is located in the city of Lund in the Swedish province of Scania. The university was officially foun ...

. Before this, and sometimes after, many species of ''Pyropia'' were placed in '' Porphyra'', a different genus of red alga. New species of ''Pyropia'' are still being discovered, for example in 2013 research done on New Zealand plants was able to move '' Pyropia plicata'' from ''Porphyra''.

Description

''Pyropia'' species are red algae with a discoid holdfast and short stipe. They have folded blades, which are membranous and monostromatic, coming in red, brown, and dark green colorations. These folded blades may also look like fronds until unfolded. These blades reach up to one meter in length in some species, but are generally around 20 centimeters in diameter.

Distribution

''Pyropia'' grows in intertidal zones and down to 10 meters in some bodies of water based on clarity and substrate. It grows in large swaths, attaching itself to stones and shells, covering most of the bottom. ''Pyropia'' can be found globally in warm-temperate and extratropical oolwaters.

Ecology

''Pyropia'' species, which reside in the upper intertidal zone, endure many stresses, including intense direct light, temperature fluctuation, osmotic stress, salinity fluctuation, and desiccation. They are especially able to handle heat stress; some ''Pyropia'' species will halt metabolic systems that are not essential to homeostasis, such as photosynthesis. Other species will use increased lipid production to fight desiccation. The ability of ''Pyropia'' species to adapt to deal with these stresses makes them heavily studied organisms. One of the threats to ''Pyropia'' is fungal infections by ''

Alternaria ''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major Phytopathology, plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead t ...

'' sp. ZL-1, which has been observed in farming environments on ''Pyropia yezoensis'' ''.'' The fungus kills ''Pyropia'' cells and leaves brown rust-like spots on the outside of the blades.

Use

Within the genus ''Pyropia'' multiple species are used for

(edible seaweed), ''Pyropia yezoensis'' and ''P. haitanensis'' being most popular. It is a two-billion-dollar industry with most major growers located in China, Korea, and Japan. Nori contains substantial amounts of

Vitamin B12 Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. One of eight B vitamins, it serves as a vital cofactor (biochemistry), cofactor in DNA synthesis and both fatty acid metabolism, fatty acid and amino a ...

according to a 2014 paper. However, the Academy of Nutrition and Dietetics considers this source unreliable for

vegan Veganism is the practice of abstaining from the use of animal products and the consumption of animal source foods, and an associated philosophy that rejects the commodity status of animals. A person who practices veganism is known as a ve ...

Species

''Pyropia'' currently contains 80 confirmed species.

Gallery

File:Naturalis Biodiversity Center - L.4084188 - Porphyra thuretii Setch. and E.Y.Dawson - Algae - Plant type specimen.jpeg File:Porphyra haitanensis life cycle.JPG File:Naturalis Biodiversity Center - L.4084451 - Porphyra columbina Mont. - Algae - Plant type specimen.jpeg

Notes

References

External links

* * {{Taxonbar, from=Q3411341 Bangiophyceae Red algae genera Edible algae Seaweeds Edible seaweeds