Asakusanori: Porphyra tenera Kjellman

Asakusanori is Japanese name and it is called Amanori.This seaweed was harvested and processed in Asakusa early in the Edo period,it is the origin of Japanese name.This seaweed’s scientific name is Porphyra tenera Kjellman.

Asakusanori is Red seaweed, and a kind of amanori.It is genus of laver ,tleve are 30 kind of in japan.It is difficult for amanori to classify the seed because the figure is simple.Moreover, the figure changes responding to the environment.Adaptability to the environmental condition is wide,because as for the amanori, the body structure is easy.If it grows on the shore reef in the open sea where the wave is rough in the high salinity,it is likely to grow in the basin shallow water of a quiet wave in the low salinity.Most a growing vigorous thickly from winter to spring.it is It an alga for one year. But it declines in early summer.

Asakusanori’s total size is from 5 to 30cm,the width is from 1 to 15cm. Asakusanori is the typical of seaweed species.It is distributed in the Inland Sea,Pacific coast in the main island of Japan,Kyusyu,the Korean Peninsula,china,from the Tropical zone to the Frigid zone.

It is designated as an endangered species .The habitat decreases sharply by the environment’s that is appropriate for natural growth being lost.This cause for example land reclamation reclamation water pollution.Moreover,the shell in bottom of the sea is buried in mud and the growth condition of the trichome period has deteriorated.The habitat is found from a recent investigation, it is eight places in the whole country.But,there is no protection of a wild population. A natural purple laver is not gathered in various parts of Japan now. The purple laver has decreases on a nationwide scale. It is a cultivation kind of susabinori; Porphyra yezoensis Ueda.Asakusanori is the cultivation all one fishing. It is cultivated in nationwide various places. Aquaculture Asakusanori used for food. Aquaculture is winter in every place and it collected when grew about 20cm.

In summer this laver body is like a thread, and it digs a hole in the shell and lives ther. The trichome forms the sporangium and discharges the husk spore. It is parasitic in the rock, the tree, and the stake of the bamboo etc. It becomes a foliaceous body and it grows thickly in autumn.The other type becomes a foliaceous body. It is parasitic, and grows up when a single spore is discharged from the part of a foliaceous body in the surrounding area. The foliaceous body grows in the last ten days of September, and the period of maturity is from December to February. It grows especially in the basin and the vicinity of the mouth of a river where nourishment is abundant. Many of foliaceous bodies are monoecious but dioecious occasionally.The carpogonium and the sperm uteri are formed when maturing. When the sperm connects it to the carpogonium, the carpogonium is enlarged, divided, and discharges the spore of carpospore.

The cell is one layer and filmy. An asteroidal plastid pyrenoid (centers in the chloroplast where carbon dioxide is fixed) is seen in each cell.

Asakusanori is on the verge of extinction. But Amanori are found in Kochi along the coastline all winter.