Laminaria hyperborea

Palmentang ( Laminaria hyperborea )

The Palmentang ( Laminaria hyperborea ) is a Braunalgenart of the order Laminariales. It forms on the coasts of the North East Atlantic extended Tangwälder and is also found in the North Sea and Baltic Sea. It is used commercially for the production of alginate.

• 6.1 Notes and references

Description

The Palmentang is a handsome perennial Tang of palm- like habit, which can be 2 to 3 meters long. The sporophyte is attached with a strong claw-like, conical holdfast ( rhizoids ) on rocky ground. Above it, the thallus is divided into a stick ( Cauloid ) and a sheet-like surface ( Phylloid ) and has differentiated tissue.

The stem is round, stiff and has a rough, wrinkled surface, which is often populated by red algae. The length of the stem reaches populated depending on the water depth from 0.2 to 1.5 (rarely to 2) m. It consists of a cortex and a central body, run in the real pathways and secondary growth is recognizable by annual rings. The brown, leathery, rough Phylloid with a length up to 1.5 m is divided finger-shaped and is characterized by a heart-shaped leaf growth.

The Palmentang differs from similar kelp ( Laminaria digitata ) by its round, stiff, rough stem and the lighter leaf area with heart shaped ausgerandeter leaf base.

Deciduous

The Journal of Palmentangs is renewed every year. Stored in the old deciduous reserve materials are transported to the growth zone to early winter. With increasing light grows in the spring of the leaf grass-roots approach a new Phylloid, where the last year's sheet still seated until early May. Then the old foliage is mostly demolished in a storm and washed in large quantities to the beach.

Development

The Palmentang has a change of generation with two very different generations. The visible is the diploid sporophyte Tang. In autumn and winter the tubular sporangia are formed on the Phylloid at irregular darker spots ( sori ). In each sporangium produced by meiosis 32 mobile zoospores. These grow to the haploid gametophyte, which consists of microscopic, branched hyphae. At low temperatures ( 4-10 ° C), the eggs and sperm are formed here. After fertilization, the zygote sets and germinates into a young sporophyte. The young plants are fertile for the first time with two or three years.

The Palmentang can be up to 15 years old.

Ecology

The stems of Palmentangs are often occupied by numerous epiphytic red algae Palmaria palmata example, Phycodrys rubens, Membranoptera alata, Ptilota gunneri and Cryptopleura ramosa. In greater depth the thalli are often overgrown by bryozoans ( Membranipora membranous ).

With massive grazing by sea urchins Strongylocentrotus droebachiensis green stocks of Palmentangs can be completely suppressed. In the overgrazed areas then dominate more than five years coralline encrusting algae and sea urchins.

Occurrence

The Palmentang is common off the coasts of the eastern North Atlantic from Iceland and Norway to Spain and the Canary Islands. It occurs on a suitable substrate in the North Sea and Baltic Sea, for example, in Helgoland.

He settled the subtidal on rocky ground, forming dense Tangwälder. In the North Sea it grows in 1-4 m depth below the low-water line as a closed stock, down to a maximum depth of 8 m, it comes only patchy ago. However, in clear water it can grow forming stands up to 24 m depth and to penetrate to a depth of 32 m.

System

The first description of Palmentangs was made in 1766 by Johan Ernst Gunnerus under the name Fucus hyperboreus (In: Fauna norvegica 34, Figure 3, # 61). Michael Heggelund Foslie put the type in 1884 in the genus Laminaria (In: About the kelp Norway Christiania Videnskabers Selskabs Forhandlinger 14. P. 42).

Laminaria hyperborea synonyms for ( Gunnerus ) Foslie are Fucus hyperboreus Gunnerus, Fucus scoparius Ström, Hafgygia cloustonii ( Edmondston ) Areschoug, Laminaria Laminaria hyperborea cloustonii Edmondston and f compressa Foslie.

Laminaria hyperborea belongs to the family Laminariaceae within the order of Laminariales.

Use

Previously, the alluvial or harvested at low tide algae were used as fertilizer. In the Middle Ages, the incineration of the algae ( kelp) of economic importance, in order to extract alkalis, which were needed for the soap and glass production. Later, the Tangveraschung came again to produce iodine to blossom.

Today Palmentang is a major supplier of alginate, which is used for example in the food, cosmetics, textile, rubber and paper industries. The main suppliers are Norway and Scotland. The crop in Ireland was completed in recent years.

Swell

• P. Korn man P.H. Sahling: seaweed from Helgoland - Benthic green, brown and red algae. Biologische Anstalt Helgoland, Hamburg 1983, ISSN 0017-9957, pp. 144-149. (Sections description, Deciduous, development, occurrence, ecology, utilization )