Porphyra purpurea
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Porphyra purpurea , |
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| ( Roth ) C. Agardh |
Porphyra purpurea , seldom also called "purple leaf" or "red purple wrack", is a species of purple wrack within the red algae . It is widespread on the sea coasts and is also found in the North Sea. The alga is used as a food.
description
Porphyra purpurea has a leaf-like, flat, tender-skinned thallus that is brown-red to brownish in color. The size reaches up to 40 cm in length (rarely up to 100 cm) and 5 to 20 cm in width. The shape of the thallus flap is very variable and can be narrowly lanceolate, broadly tongue-shaped or oval, sometimes divided into several. The edge is often wavy and wrinkled. The seaweed is attached to the ground with a basal or eccentric adhesive disc.
Development cycle
Porphyra purpurea can be found throughout the year, especially from July to October in the North Sea. The visible flap of the thallus is the gametophyte . The male and female gametes are formed on the same or on different specimens at the edge of the thallus ( trioceus ). The male gametes arise in yellowish-white areas in packet-shaped spermatangia . After fertilization, the female gametes divide several times and form packets of zygotospores. After being released, these germinate into microscopic, branched cell threads (conchocelis stage), which settle on and in the calcareous shells of mussels or barnacles . Conchospores are formed on thicker side branches, from which a flat purple wrack grows again.
Occurrence
Porphyra purpurea is widespread on the sea coasts of the cold-temperate zone: in the northeast Atlantic from Iceland to northern France , off western Greenland and the Faroe Islands , in the Mediterranean, as well as in the northwest and northeast Pacific . The species was also found on the coast of Pakistan and Sri Lanka and off Australia .
In the German Bight , Porphyra purpurea occurs near Helgoland and in the North and East Frisian Wadden Sea .
The alga grows on firm ground in the upper to middle tidal zone . It colonizes stones and rocks or, less often, other algae, especially Fucus species. At low tide, its thin thallus lobes nestle against the surface and cover it like a glossy layer of varnish.
Systematics
The first scientific description was made in 1797 by Albrecht Wilhelm Roth under the name Ulva purpurea (In: Catalecta botanica , p. 209). Carl Adolph Agardh placed the species in the genus Porphyra in 1824 . As early as 1788 Roth had described the species Ulva purpureoviolacea , which is now considered a synonym for Porphyra purpurea . Thus, this older name would have priority according to the nomenclature rules , but Ulva purpurea was established in 1999 as "Nomen conservandum". Further taxonomic investigations are necessary for the exact delimitation of the diverse species.
As synonyms are Phyllona purpurea (Roth) Wall Roth , Porphyra amethystea Kiitzing , Porphyra purpureoviolacea (Roth) V.Krishnamurthy , Porphyra rediviva J.W.Stiller & JRWaaland , Porphyra vulgaris C.Agardh , Ulva purpurea Roth , Ulva purpureoviolacea Roth and Ulva umbilical var. purpurea (Roth) Wahlenberg .
use
Porphyra purpurea is mainly used as a food . In England and Ireland (as well as related Porphyra species) it is called "Laver". In Japan it is known as "Asakusa nori" or "Hoshinori" and is used to prepare sushi and other dishes. The harvest takes place from wild stocks or from cultures: twigs are stuck into the mud on which the algae settle in abundance.
The extract from Porphyra purpurea has a strong antioxidant effect .
Individual evidence
- ↑ a b c Wolfram Braune: Marine algae. A color guide to the common benthic green, brown and red algae of the world's oceans . Ruggell: Gantner, 2008, ISBN 978-3-906166-69-8 , pp. 266-267.
- ↑ a b Seaweed Industry Association - Porphyra purpurea ( Memento of the original from September 9, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed November 18, 2015.
- ↑ a b c P. Kornmann, PH Sahling: Sea algae from Helgoland - Benthic green, brown and red algae. Biological Institute Helgoland, Hamburg 1983, ISSN 0017-9957 , pp. 266-267.
- ↑ a b c d e Michael D. Guiry in Michael D. Guiry, GM Guiry: Porphyra purpurea - In: Algaebase - World-wide electronic publication, National University of Ireland, Galway, accessed November 18, 2015.
- ↑ Dirk Schories, Uwe Selig, Hendrik Schubert: Species and synonym list of the German marine macroalgae based on historical and recent records (list of species and synomes of macroalgae in German coastal waters - evaluation of historical and recent findings) . In: Rostock. Marine biologist Contribution ., Issue 21, 2009, p. 62. PDF file
