Navel purple wrack
| Navel purple wrack | ||||||||||||
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Navel
purple wrack ( Porphyra umbilicalis ), |
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| Porphyra umbilicalis | ||||||||||||
| Kützing |
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The umbilical purple wrack ( Porphyra umbilicalis ), also known as purple wrack , skin wrack or navel skin wrack , is a type of red algae . It is widespread on the sea coasts, particularly in the North Atlantic , and is also found in the North Sea . It is used in the cosmetics industry and as food.
description
The umbilical purple wrack has a thallus 10 to 20 cm long, which, depending on the season and location, is purple-red, red-brown, greenish-purple, olive or brownish in color. It forms a wavy, wrinkled flap with a smooth, gelatinous surface. In older specimens, the initially basal organ of attachment gets more and more into the middle of the lobe due to fan-shaped growth and forms a "navel" there. The edge of the thallus can also be divided into individual lobes. The thallus surface consists of only one layer of cells.
When the tide is out, the thalli hang down from their base, but are too coarse to cling to completely and dry out into hard braids at the bottom. Often they resemble the remains of dark plastic wrap.
Development cycle
The thallus lobe of the umbilical purple kelp is the gametophyte . The male and female gametes are usually formed on different specimens at the edge of the thallus. Packets of 128 male gametes each arise in yellowish-white areas (4 times 4 cells each in 8 layers). The female gametes divide several times after fertilization and form dark red packets of 16 zygotospores (each 2 times 4 cells in 2 layers). These spores are released and germinate into microscopic, branched cell threads, which are called the conchocelis stage. The conchocelis cell threads settle on the calcareous shells of mussels or barnacles and anchor themselves in them. Spores (conchospores) are formed on thicker side branches, from which the flat Porphyra -Thalli grow again. Occasionally, vegetative reproduction takes place through neutral spores, which form new thallus lobes without fertilization.
Occurrence
The umbilical purple wrack is widespread on the sea coasts: it is found in the Atlantic (North, Northeast, Northwest, Southwest Atlantic), Mediterranean , Indian Ocean , Caribbean , Northwest and Northeast Pacific , Antarctica and off Australia . Its focus is in the North Atlantic, and the global occurrences may be a complex of several species.
The umbilical purple wrack is the most common type of porphyra on the European coasts . In the German Bight it occurs near Heligoland and in the North and East Frisian Wadden Sea .
He settled the intertidal zone to the high-water line. You can find it all year round on harbor walls, breakwaters and buoys together with Prasiola stipitata and Blidingia minima , in summer also in the rocky tidal flats between bladder wrack ( Fucus vesiculosus ) and sawwrack ( Fucus serratus ). Often it also grows on mussels. It prefers wave-exposed coasts and also endures prolonged drying out.
The very similar species Porphyra laciniata , Porphyra linearis , Porphyra ochotensis , Porphyra purpurea and Pyropia leucosticta occur on the North Sea coasts , from which Porphyra umbilicalis can sometimes only be reliably distinguished by microscopic examination.
Systematics
The first scientific description was made in 1843 by Friedrich Traugott Kützing . Since 2008, this has no longer been regarded as a new combination of Carl von Linné 's ulva umbilicalis , but as a valid first description.
Synonyms are Porphyra insolita P. Kornmann & P.-H.Sahling , Porphyra umbilicalis (L.) J. Agardh , Porphyra umbilicalis f. epiphytica F.S. Collins , Porphyra umbilicalis var. vulgaris Ruprecht , Ulva umbilicalis L. , Wildemania laciniata (Lightfoot) DeToni and Wildemania laciniata var. umbilicalis (L.) Malard ex Chalon .
use
The umbilical purple wrack is - together with other types of porphyra - called "laver" in Great Britain and Ireland and is traditionally used as a food . In Wales it forms the main component of "laverbread", an algae paste made from cooked and crushed porphyry , which is usually consumed fried. It also serves as a substitute for nori , for example in snack mixes. It is also used as an additive for pet food. Purple kelp contains a lot of protein , vitamins A, C, E and B, minerals and polyunsaturated omega-3 fatty acids .
The use of purple seaweed in the cosmetics industry is of major economic importance : Its ingredients are marketed in Europe and the USA as natural UV radiation protection in sun creams , against light-induced skin aging and for skin care . Purple wrack is harvested in France , Great Britain and Ireland, Canada and the northeastern USA. The algae are carefully cut from their adherent organs with scissors or knives.
Individual evidence
- ↑ a b c d e f 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. 267-268.
- ↑ a b c d e P. Kornmann, PH Sahling: Sea algae from Helgoland - Benthic green, brown and red algae. Biological Institute Helgoland, Hamburg 1983, ISSN 0017-9957 , pp. 264-265.
- ↑ a b c d Michael D. Guiry in Michael D. Guiry, GM Guiry: Porphyra umbilicalis - In: Algaebase - World-wide electronic publication, National University of Ireland, Galway, accessed November 9, 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
- ↑ Michael Guiry: The Seaweed Site: information on marine algae: Porphyra umbilicalis , accessed November 9, 2015.
- ↑ a b c Seaweed Industry Association - Porphyra umbilicalis ( 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 9, 2015.
