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Lithophyllum Orbiculatum
''Lithophyllum orbiculatum'' is a species of thalloid coralline algae, which are a red algae whose cell walls contain calcareous deposits. History Due to being very similar, the species of coralline algae '' Lithophyllum crouanii'', was often misidentified as ''Lithophyllum orbiculatum''. Distribution & habitat This species is often found in the north of the Atlantic Ocean and in the Mediterranean Sea. It has also been collected in the Indian Ocean more recently. The coralline algae lives in the mid-tide and higher level pools, occasionally exposed to air. The coralline algae mostly grows on hard rock surfaces and was not found on any limestone or slate rock. It can also be found growing on the shells of mollusks that live in the same area, however the algae was physically reduced on the shells. Over time the coralline algae will come together on the surfaces to form large colonies and cover the vast majority of a surface. Ecology The coralline algae often acts as a pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithophyllum Crouanii
''Lithophyllum'' is a genus of thalloid red algae belonging to the family Corallinaceae. Fossil record This genus is known in the fossil record from the Silurian to the Quaternary (from about 418.7 to 0.0 million years ago). Fossils of species within this genus have been found in Europe, United States, South America, Egypt, Iran, Iraq, India, Japan and Australia. Description The monomerous, crustose thalli are composed of a single system of filaments which grow close to the underlying surface. ''Lithophyllum'' reproduces by means of conceptacles. The epithallus is periodically shed to avoid organisms growing on top of the alga. Species The valid species currently considered to belong to this genus are: *'' Lithophyllum acanthinum'' Foslie, 1907 *''Lithophyllum accedens'' Foslie, 1907 *''Lithophyllum acrocamptum'' Heydrich, 1902 *''Lithophyllum aequum'' Foslie, 1907 *'' Lithophyllum albanense'' Lemoine, 1924 *'' Lithophyllum almanense'' Lemoine, 1920 *''Lithop ... [...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 ... [...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 (biology), class), and mostly consist of multicellular, ocean, marine algae, including many notable seaweed, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth#Surface, Earth's surface and about 29% of its water surface area. It is known to separate the "Old World" of Africa, Europe and Asia from the "New World" of the Americas in the European perception of Earth, the World. The Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Europe and Africa to the east, and North America, North and South America to the west. As one component of the interconnected World Ocean, it is connected in the north to the Arctic Ocean, to the Pacific Ocean in the southwest, the Indian Ocean in the southeast, and the Southern Ocean in the south (other definitions describe the Atlantic as extending southward to Antarctica). The Atlantic Ocean is divided in two parts, by the Equatorial Counter Current, with the North(ern) Atlantic Ocean and the South(ern) Atlantic Ocean split at about 8th paralle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the east by the Levant. The Sea has played a central role in the history of Western civilization. Geological evidence indicates that around 5.9 million years ago, the Mediterranean was cut off from the Atlantic and was partly or completely desiccated over a period of some 600,000 years during the Messinian salinity crisis before being refilled by the Zanclean flood about 5.3 million years ago. The Mediterranean Sea covers an area of about , representing 0.7% of the global ocean surface, but its connection to the Atlantic via the Strait of Gibraltar—the narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates the Iberian Peninsula in Europe from Morocco in Africa—is only wide. The Mediterranean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by the Southern Ocean or Antarctica, depending on the definition in use. Along its core, the Indian Ocean has some large marginal or regional seas such as the Arabian Sea, Laccadive Sea, Bay of Bengal, and Andaman Sea. Etymology The Indian Ocean has been known by its present name since at least 1515 when the Latin form ''Oceanus Orientalis Indicus'' ("Indian Eastern Ocean") is attested, named after India, which projects into it. It was earlier known as the ''Eastern Ocean'', a term that was still in use during the mid-18th century (see map), as opposed to the ''Western Ocean'' ( Atlantic) before the Pacific was surmised. Conversely, Chinese explorers in the Indian Ocean during the 15th century called it the Western Oceans. In Anci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusca
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epithallus
The epithallium or epithallus is the outer layer of a crustose coralline alga, which in some species is periodically shed to prevent organisms from attaching to and overgrowing the alga. Structure It is defined as the cells above the intercalary meristem; these are not involved in photosynthesis. In ''Phymatolithon'', the epithallium is usually one cell thick, whereas in other genera, such as '' Pseudolithophyllum'', multiple cells exist, with the thickness determined by the difference between their rate of production at the intercalary meristem, and the rate of shedding at the surface; thicknesses of 16 cells or more, spanning 100 µm, have been measured in a representative coralline ('' Clathromorphum''). The thickness is variable within species; in ''Lithothamnion'', a single cell thickness is the norm, but three- or four-cell thick regions are also common. The epithallus sometimes overlies the roof of conceptacles, which are exposed only when the overlying epithallus is even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithophyllum Incrustans
''Lithophyllum incrustans'', also known by its common names coraline crust and paint weed, is a small pinkish species of seaweed. Description This is a small encrusting,Fritch, F.E. 1965. ''The Structure and Reproduction of the Algae Volume 2.'' Cambridge University Press p 508 calcareous alga, growing epiphytically as a flat lobed plant up to 10 cm in diameter and up to several mm forming thick adherent crusts. It can become knobbly with overlapping lobes and a smooth surface. In colour it is pinkish but may become bleached.Irvine, L.M. and Chamberlain, Y.M. 1994 ''Seaweeds of the British Isles Volume 1 Rhodophyta Part 2B Corallinales, Hildenbrandiales''pp75 - 81 The Natural History Museum Reproduction Tetrasporangial and bisporangial conceptacles occur sunken pits.Hardy, F.G. and Guiry, M.D. 2003. ''A Check-list and Atlas of the Seaweeds of Britain and Ireland.'' The British Phycological Society 2003. Plants usually gametangial, Spermatangial conceptacles in shallow c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecological Succession
Ecological succession is the process of change in the species structure of an ecological community over time. The time scale can be decades (for example, after a wildfire) or more or less. Bacteria allows for the cycling of nutrients such as carbon, nitrogen and sulphur. The community begins with relatively few pioneering plants and animals and develops through increasing complexity until it becomes stable or self-perpetuating as a climax community. The "engine" of succession, the cause of ecosystem change, is the impact of established organisms upon their own environments. A consequence of living is the sometimes subtle and sometimes overt alteration of one's own environment. Succession is a process by which an ecological community undergoes more or less orderly and predictable changes following a disturbance or the initial colonization of a new habitat. Succession may be initiated either by formation of new, unoccupied habitat, such as from a lava flow or a severe landsl ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrasporangia
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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
