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Fucus Nereideus
''Fucus'' is a genus of brown algae found in the intertidal zones of rocky seashores almost throughout the world. Description and life cycle The thallus is perennial with an irregular or disc-shaped holdfast or with haptera. The erect portion of the thallus is dichotomous or subpinnately branched, flattened and with a distinct midrib. Gas-filled pneumatocysts (air-vesicles) are present in pairs in some species, one on either side of the midrib. The erect portion of the thallus bears cryptostomata and caecostomata (sterile surface cavities). The base of the thallus is stipe-like due to abrasion of the tissue lateral to the midrib and it is attached to the rock by a holdfast. The gametangia develop in conceptacles embedded in receptacles in the apices of the final branches. They may be monoecious or dioecious. These algae have a relatively simple life cycle and produce only one type of thallus which grows to a maximum size of 2 m. Fertile cavities, the conceptacles, con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fucus Serratus
''Fucus serratus'' is a seaweed of the north Atlantic Ocean, known as toothed wrack or serrated wrack. Description and reproduction ''Fucus serratus'' is a robust alga, olive-brown in colour and similar to '' Fucus vesiculosus'' and ''Fucus spiralis''. It grows from a discoid holdfast up to long. The fronds are flat, about wide, bifurcating, and up to long including a short stipe. It branches irregularly and dichotomously. The flattened blade has a distinct midrib and is readily distinguished from related taxa by the serrated edge of the fronds. It does not have air vesicles, such as are found in ''F. vesiculosus'', nor is it spirally twisted like ''F. spiralis''. Male and female receptacles are on different plants. The lamina shows cryptostomata – small cavities which produce colourless hairs. The reproductive bodies form in conceptacles sunken in receptacles towards the tips on the branches. In these conceptacles oogonia and antheridia are produced and after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
