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Hildenbrandia
''Hildenbrandia'' is a genus of thalloid red alga comprising about 26 species. The slow-growing, non-mineralized thalli take a crustose form. ''Hildenbrandia'' reproduces by means of conceptacles and produces tetraspores. Morphology ''Hildenbrandia'' cells are around 3–5 μm in diameter and the filaments are around 50–75 μm in height. The thallus comprises two layers: the hypothallus, which attaches to the rock, and the perithallus, a pseudoparenchymous layer comprising vertical filaments, which unlike coralline red algae is not further differentiated. Growth ''Hildenbrandia'' comprises orderly layers of vertical oblong cells with thick vegetative cell walls, occasionally connected by secondary pit connections with pit plugs in the septal pores. It grows at its margins, away from the centre, and is able to quickly repair any gaps arising by regenerating from a basal layer of cells. As plants become more mature, they become multi-layered and strong ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hildenbrandia Rivularis
''Hildenbrandia'' is a genus of thalloid red alga comprising about 26 species. The slow-growing, non-mineralized thalli take a crustose form. ''Hildenbrandia'' reproduces by means of conceptacles and produces tetraspores. Morphology ''Hildenbrandia'' cells are around 3–5 μm in diameter and the filaments are around 50–75 μm in height. The thallus comprises two layers: the hypothallus, which attaches to the rock, and the perithallus, a pseudoparenchymous layer comprising vertical filaments, which unlike coralline red algae is not further differentiated. Growth ''Hildenbrandia'' comprises orderly layers of vertical oblong cells with thick vegetative cell walls, occasionally connected by secondary pit connections with pit plugs in the septal pores. It grows at its margins, away from the centre, and is able to quickly repair any gaps arising by regenerating from a basal layer of cells. As plants become more mature, they become multi-layered and stro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hildenbrandia Rubra
''Hildenbrandia rubra'' is a marine species of thalloid red alga. It forms thin reddish crusts on rocks and pebbles in the intertidal zone and the shallow subtidal zone. It is a common species with a cosmopolitan distribution, and is able to tolerate a wide range of conditions. Description This alga forms patches or larger sheets of thallus less than thick tightly attached to the substrate. The thallus is formed from a single layer of undifferentiated cells some 3 to 6 µm in diameter, arranged in rows. The surface is smooth and flat apart from slight mounds indicating the presence of conceptacles (specialized cavities containing the reproductive organs). The colour is pinkish-red or reddish-brown. Distribution and habitat ''Hildenbrandia rubra'' has a cosmopolitan distribution. Its range includes the northeastern Atlantic Ocean, from Spitsbergen to the Mediterranean Sea and most of the western coasts of Africa, and the northwestern Atlantic from Maine to the Caribbean Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conceptacle
Conceptacles are specialized cavities of marine and freshwater algae that contain the reproductive organs. They are situated in the receptacle and open by a small ostiole.Boney, A.D. (1969). ''A Biology of Marine Algae''. Hutchinson Educational Ltd, London Conceptacles are present in Corallinaceae,Irvine, L.M. and Chamberlain, Y.M. (1994). ''Seaweeds of the British Isles''. Volume 1, Part 2B. Natural History Museum, London. and Hildenbrandiales, as well as the brown Fucales. In the Fucales there is no haploid phase in the reproductive cycle and therefore no alternation of generations.Fritsch, F.E. (1945). ''The Structure and Reproduction of the Algae''. Vol 2. Cambridge University Press, Cambridge The thallus is a sporophyte.Smith, G.M. (1938). ''Cryptogamic Botany. Algae and Fungi''. Second edition, Volume ''1'', McGraw-Hill Bok Company, Inc. The diploid plants produce male (antheridia) and female (oogonia) gametangia by meiosis. The gametes are released into the surrounding wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coralline Algae
Coralline algae are red algae in the order Corallinales. They are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls. The colors of these algae are most typically pink, or some other shade of red, but some species can be purple, yellow, blue, white, or gray-green. Coralline algae play an important role in the ecology of coral reefs. Sea urchins, parrot fish, and limpets and chitons (both mollusks) feed on coralline algae. In the temperate Mediterranean Sea, coralline algae are the main builders of a typical algal reef, the ''Coralligène'' ("coralligenous"). Many are typically encrusting and rock-like, found in marine waters all over the world. Only one species lives in freshwater. Unattached specimens ( maerl, rhodoliths) may form relatively smooth compact balls to warty or fruticose thalli. A close look at almost any intertidal rocky shore or coral reef will reveal an abundance of pink to pinkish-grey patches, distributed throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Algae
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (class), and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats but relatively rare in freshwaters. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity. The red algae form a distinct group characterized by having eukaryotic cells without flagella and centrioles, chloroplasts that l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blick Mead
Blick Mead is a chalkland spring in Wiltshire, England, separated by the River Avon from the northwest edge of the town of Amesbury. It is close to an Iron Age hillfort known as Vespasian's Camp and about a mile east of the Stonehenge ancient monument. Evidence from archaeology excavation at the site since 2005, indicates that there was continuous human habitation from 10,000 BP (8,000 BCE) to 6,000 BP (4,000 BCE). 35,000 worked flints and 2400 animal bones, some cooked, mostly from aurochsen, have been found at the site. There is also the remains of a pit dwelling. A few finds have been used to radiocarbon date the time of settlement. It is thought that the site would have been an attractive place to camp or dwell, with a spring that never freezes over; the issuing water has a constant temperature of around . Oxygen isotope There are three known stable isotopes of oxygen (8O): , , and . Radioactive isotopes ranging from to have also been characterized, all short ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemma (botany)
A gemma (plural ''gemmae'') is a single cell, or a mass of cells, or a modified bud of tissue, that detaches from the parent and develops into a new individual. This type of asexual reproduction is referred to as fragmentation. It is a means of asexual propagation in plants. These structures are commonly found in fungi, algae, liverworts and mosses, but also in some flowering plants such as pygmy sundews and some species of butterworts. Vascular plants have many other methods of asexual reproduction including bulbils and turions. In mosses and liverworts The production of gemmae is a widespread means of asexual reproduction in both liverworts and mosses. In liverworts such as ''Marchantia'', the flattened plant body or thallus is a haploid gametophyte A gametophyte () is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algaebase
AlgaeBase is a global species database of information on all groups of algae, both marine and freshwater, as well as sea-grass. History AlgaeBase began in March 1996, founded by Michael Guiry. Text was copied from this source, which is available under Attribution 4.0 International (CC BY 4.0)licence. (Sehere. By 2005, the database contained about 65,000 names. In 2013, AlgaeBase and the Flanders Marine Institute (VLIZ) signed an end-user license agreement regarding the Electronic Intellectual Property of AlgaeBase. This allows the World Register of Marine Species (WoRMS) to include taxonomic names of algae in WoRMS, thereby allowing WoRMS, as part of the Aphia database, to make its overview of all described marine species more complete. Synchronisation of the AlgaeBase data with Aphia and WoRMS was undertaken manually until March 2015, but this was very time-consuming, so an online application was developed to semi-automate the synchronisation, launching in 2015 in conju ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wiltshire Archaeological And Natural History Magazine
''Wiltshire Archaeological and Natural History Magazine'' is a county journal published by the Wiltshire Archaeological and Natural History Society (WANHS), based in Devizes, England. It has been published almost annually since 1854 and is distributed to the Society's members and subscribers, and exchanged with other linked societies. Online availability The Biodiversity Heritage Library, in partnership with the Internet Archive and the Natural History Museum A natural history museum or museum of natural history is a scientific institution with natural history collections that include current and historical records of animals, plants, fungi, ecosystems, geology, paleontology, climatology, and more. ... Library, London, has a near-complete set of scanned volumes. , the collection goes as far as volume 106 (2013). References External links ''WANHM'' on the Wiltshire Archaeological and Natural History Society website [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stonehenge
Stonehenge is a prehistoric monument on Salisbury Plain in Wiltshire, England, west of Amesbury. It consists of an outer ring of vertical sarsen standing stones, each around high, wide, and weighing around 25 tons, topped by connecting horizontal lintel stones. Inside is a ring of smaller bluestones. Inside these are free-standing trilithons, two bulkier vertical sarsens joined by one lintel. The whole monument, now ruinous, is aligned towards the sunrise on the summer solstice. The stones are set within earthworks in the middle of the densest complex of Neolithic and Bronze Age monuments in England, including several hundred ''tumuli'' (burial mounds). Archaeologists believe that Stonehenge was constructed from around 3000 BC to 2000 BC. The surrounding circular earth bank and ditch, which constitute the earliest phase of the monument, have been dated to about 3100 BC. Radiocarbon dating suggests that the first bluestones were raised between 2400 and 2200 BC, althou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GBIF
The Global Biodiversity Information Facility (GBIF) is an international organisation that focuses on making scientific data on biodiversity available via the Internet using web services. The data are provided by many institutions from around the world; GBIF's information architecture makes these data accessible and searchable through a single portal. Data available through the GBIF portal are primarily distribution data on plants, animals, fungi, and microbes for the world, and scientific names data. The mission of the GBIF is to facilitate free and open access to biodiversity data worldwide to underpin sustainable development. Priorities, with an emphasis on promoting participation and working through partners, include mobilising biodiversity data, developing protocols and standards to ensure scientific integrity and interoperability, building an informatics architecture to allow the interlinking of diverse data types from disparate sources, promoting capacity building and catal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AlgaeBase
AlgaeBase is a global species database of information on all groups of algae, both marine and freshwater, as well as sea-grass. History AlgaeBase began in March 1996, founded by Michael Guiry. Text was copied from this source, which is available under Attribution 4.0 International (CC BY 4.0)licence. (Sehere. By 2005, the database contained about 65,000 names. In 2013, AlgaeBase and the Flanders Marine Institute (VLIZ) signed an end-user license agreement regarding the Electronic Intellectual Property of AlgaeBase. This allows the World Register of Marine Species (WoRMS) to include taxonomic names of algae in WoRMS, thereby allowing WoRMS, as part of the Aphia database, to make its overview of all described marine species more complete. Synchronisation of the AlgaeBase data with Aphia and WoRMS was undertaken manually until March 2015, but this was very time-consuming, so an online application was developed to semi-automate the synchronisation, launching in 2015 in conju ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
