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Millepora Dichotoma
''Millepora dichotoma'', the net fire coral, is a species of hydrozoan, consisting of a colony of polyps with a calcareous skeleton. Description ''M. dichotoma'' is a colonial hermatypic coral with a calcareous endoskeleton. They form colonies up to 60 cm wide, but clumps of colonies may be several meters across. They initially build as encrusting coral, adhering themselves to hard substrate. The encrusting formations further develop into other growth forms, such as lace-like, leaf-like blades, and box-work. What growth form an individual develops into is highly dependent on the depth and location of growth as well as on the turbidity of the water in a given location. More fragile structures, such as lace-like, succeed better in deeper, less turbulent waters, whereas box-work forms are able to better succeed in harsher environments. As in other hermatypic corals, part of the metabolism of fire corals relies on zooxanthellae. Symbiotic zooxanthellae give ''M. dichotom''a t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter Forsskål
Peter Forsskål, sometimes spelled Pehr Forsskål, Peter Forskaol, Petrus Forskål or Pehr Forsskåhl (11 January 1732 – 11 July 1763) was a Swedish-speaking Finnish explorer, orientalist, naturalist, and an apostle of Carl Linnaeus. Early life Forsskål was born in Helsinki, now in Finland but then a part of Sweden, where his father, Finnish priest , was serving as a Lutheran clergyman, but the family migrated to Sweden in 1741 when the father was appointed to the parish of Tegelsmora in Uppland and the archdiocese of Uppsala. As was common at the time, he enrolled at Uppsala University at a young age in 1742, but returned home for some time and, after studies on his own, rematriculated in Uppsala in 1751, where he completed a theological degree the same year. Linnaeus's disciple In Uppsala Forsskål was one of the students of Linnaeus, but apparently also studied with the orientalist Carl Aurivillius, whose contacts with the Göttingen orientalist Johann David Michae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthic Zone
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "the depths." Organisms living in this zone are called benthos and include microorganisms (e.g., bacteria and fungi) as well as larger invertebrates, such as crustaceans and polychaetes. Organisms here generally live in close relationship with the substrate and many are permanently attached to the bottom. The benthic boundary layer, which includes the bottom layer of water and the uppermost layer of sediment directly influenced by the overlying water, is an integral part of the benthic zone, as it greatly influences the biological activity that takes place there. Examples of contact soil layers include sand bottoms, rocky outcrops, coral, and bay mud. Description Oceans The benthic region of the ocean begins at the shore line (intertida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milleporidae
Fire corals (''Millepora'') are a genus of colonial marine organisms that exhibit physical characteristics similar to that of coral. The name coral is somewhat misleading, as fire corals are not true corals but are instead more closely related to ''Hydra'' and other hydrozoans, making them hydrocorals. They make up the only genus in the monotypic family Milleporidae. Distinguishing characteristics Fire corals have a bright, yellow-green to brown skeletal covering, and are widely distributed in tropical and subtropical waters. They appear in small, brush-like growths on rocks and coral. Divers often mistake fire coral for seaweed, and accidental contact is common. Upon contact, an intense pain can be felt, lasting from two days to two weeks. Occasional relapses of post-treatment inflammation are common. Prominent side effects can include skin irritation, stinging or burning pain, erythema (skin redness), fever, and/or urticarian (hives) lesions. These side effects are due to ven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coral Bleaching
Coral bleaching is the process when corals become white due to various stressors, such as changes in temperature, light, or nutrients. Bleaching occurs when coral polyps expel the zooxanthellae (dinoflagellates that are commonly referred to as algae) that live inside their tissue, causing the coral to turn white. The zooxanthellae are photosynthetic, and as the water temperature rises, they begin to produce reactive oxygen species. This is toxic to the coral, so the coral expels the zooxanthellae. Since the zooxanthellae produce the majority of coral colouration, the coral tissue becomes transparent, revealing the coral skeleton made of calcium carbonate. Most bleached corals appear bright white, but some are blue, yellow, or pink due to pigment proteins in the coral. The leading cause of coral bleaching is rising ocean temperature due to climate change. A temperature about 1 °C (or 2 °F) above average can cause bleaching. According to the United Nations Environment Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthropogenic Hazard
Anthropogenic hazards are hazards caused by human action or inaction. They are contrasted with natural hazards. Anthropogenic hazards may adversely affect humans, other organisms, biomes, and ecosystems. They can even cause an omnicide. The frequency and severity of hazards are key elements in some risk analysis methodologies. Hazards may also be described in relation to the impact that they have. A hazard only exists if there is a pathway to exposure. As an example, the center of the earth consists of molten material at very high temperatures which would be a severe hazard if contact was made with the core. However, there is no feasible way of making contact with the core, therefore the center of the earth currently poses no hazard. Anthropogenic hazards can be grouped into societal hazards (criminality, civil disorder, terrorism, war, industrial hazards, engineering hazards, power outage, fire), hazards caused by transportation and environmental hazards. Societal hazards ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
External Fertilization
External fertilization is a mode of reproduction in which a male organism's sperm fertilizes a female organism's egg outside of the female's body. It is contrasted with internal fertilization, in which sperm are introduced via insemination and then combine with an egg inside the body of a female organism. External fertilization typically occurs in water or a moist area to facilitate the movement of sperm to the egg. The release of eggs and sperm into the water is known as spawning. In motile species, spawning females often travel to a suitable location to release their eggs. However, sessile species are less able to move to spawning locations and must release gametes locally. Among vertebrates, external fertilization is most common in amphibians and fish. Invertebrates utilizing external fertilization are mostly benthic, sessile, or both, including animals such as coral, sea anemones, and tube-dwelling polychaetes. Benthic marine plants also use external fertilization to reproduce. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamete
A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual that produces the larger type of gamete—called an ovum— and a male produces the smaller type—called a sperm. Sperm cells or spermatozoa are small and motile due to the flagellum, a tail-shaped structure that allows the cell to propel and move. In contrast, each egg cell or ovum is relatively large and non-motile. In short a gamete is an egg cell (female gamete) or a sperm (male gamete). In animals, ova mature in the ovaries of females and sperm develop in the testes of males. During fertilization, a spermatozoon and ovum unite to form a new diploid organism. Gametes carry half the genetic information of an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastrovascular Cavity
The gastrovascular cavity is the primary organ of digestion and circulation in two major animal phyla: the Coelenterates or cnidarians (including jellyfish and corals) and Platyhelminthes (flatworms). The cavity may be extensively branched into a system of canals. In cnidarians, the gastrovascular system is also known as the coelenteron, and is commonly known as a "blind gut" or "blind sac", since food enters and waste exits through the same orifice. The radially symmetrical cnidarians have a sac-like body in two distinct layers, the epidermis and gastrodermis, with a jellylike layer called the mesoglea between. Extracellular digestion takes place within the central cavity of the sac-like body. This cavity has only one opening to the outside which, in most cnidarians, is surrounded by tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detritus
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts communities of microorganisms that colonize and decompose (i.e. remineralize) it. In terrestrial ecosystems it is present as leaf litter and other organic matter that is intermixed with soil, which is denominated " soil organic matter". The detritus of aquatic ecosystems is organic material that is suspended in the water and accumulates in depositions on the floor of the body of water; when this floor is a seabed, such a deposition is denominated "marine snow". Theory The corpses of dead plants or animals, material derived from animal tissues (e.g. molted skin), and fecal matter gradually lose their form due to physical processes and the action of decomposers, including grazers, bacteria, and fungi. Decomposition, the process by which or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plankton
Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales. Marine plankton include bacteria, archaea, algae, protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in the freshwaters of lakes and rivers. Plankton are usually thought of as inhabiting water, but there are also airborne versions, the aeroplankton, that live part of their lives drifting in the atmosphere. These include plant spores, pollen and wind-scattered seeds, as well as microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyp (zoology)
A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are roughly cylindrical in shape and elongated at the axis of the vase-shaped body. In solitary polyps, the aboral (opposite to oral) end is attached to the substrate by means of a disc-like holdfast called a pedal disc, while in colonies of polyps it is connected to other polyps, either directly or indirectly. The oral end contains the mouth, and is surrounded by a circlet of tentacles. Classes In the class Anthozoa, comprising the sea anemones and corals, the individual is always a polyp; in the class Hydrozoa, however, the individual may be either a polyp or a medusa, with most species undergoing a life cycle with both a polyp stage and a medusa stage. In class Scyphozoa, the medusa stage is dominant, and the polyp stage may or may not be present, depending on the family. In those scyphozoans that have the larval planula metamorphose into a polyp, the polyp, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indo-Pacific
The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia. It does not include the temperate and polar regions of the Indian and Pacific oceans, nor the Tropical Eastern Pacific, along the Pacific coast of the Americas, which is also a distinct marine realm. The term is especially useful in marine biology, ichthyology, and similar fields, since many marine habitats are continuously connected from Madagascar to Japan and Oceania, and a number of species occur over that range, but are not found in the Atlantic Ocean. The region has an exceptionally high species richness, with the world's highest species richness being found in at its heart in the Coral Triangle, and a remarkable gradient of decreasing species richness radiating outward in al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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