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Deep Sea Fish
Deep-sea fish are fish that live in the darkness below the sunlit surface waters, that is below the epipelagic or photic zone of the sea. The lanternfish is, by far, the most common deep-sea fish. Other deep-sea fishes include the flashlight fish, cookiecutter shark, bristlemouths, anglerfish, viperfish, and some species of eelpout. Only about 2% of known marine species inhabit the pelagic environment. This means that they live in the water column as opposed to the benthic organisms that live in or on the sea floor. Deep-sea organisms generally inhabit bathypelagic ( deep) and abyssopelagic ( deep) zones. However, characteristics of deep-sea organisms, such as bioluminescence can be seen in the mesopelagic ( deep) zone as well. The mesopelagic zone is the disphotic zone, meaning light there is minimal but still measurable. The oxygen minimum layer exists somewhere between a depth of depending on the place in the ocean. This area is also where nutrients are most abundant. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humpback Anglerfish
The humpback anglerfish (''Melanocetus johnsonii'') is a species of black seadevil in the family of Black seadevil, Melanocetidae, which means "black sea monster".Froese, R., Pauly D., Eds. (2015) Melanocetus johnsonii. ''FishBase''. The species is named after James Yate Johnson, the English naturalist who discovered the first specimen in Madeira in 1863.Fitch, J.E., Lavenberg R.J. (1968). ''Deep-water teleostean fishes of California.'' University of California Press, 115. The common names include anglerfish, viperfish, and fangtoothfish.Humpback Blackdevil, ''Melanocetus johnsonii'' Gunther, 1864. Australian Museum. Historical background The first specimen of ''M. johnsonii'' was discovered by the English naturalist James Yate John ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioluminescence
Bioluminescence is the emission of light during a chemiluminescence reaction by living organisms. Bioluminescence occurs in multifarious organisms ranging from marine vertebrates and invertebrates, as well as in some Fungus, fungi, microorganisms including some bioluminescent bacteria, Dinoflagellate, dinoflagellates and terrestrial arthropods such as Firefly, fireflies. In some animals, the light is bacteriogenic, produced by symbiosis, symbiotic bacteria such as those from the genus ''Vibrio''; in others, it is autogenic, produced by the animals themselves. In most cases, the principal chemical reaction in bioluminescence involves the reaction of a substrate called luciferin and an enzyme, called luciferase. Because these are generic names, luciferins and luciferases are often distinguished by the species or group, e.g. firefly luciferin or Vargulin, cypridina luciferin. In all characterized cases, the enzyme Catalysis, catalyzes the Redox, oxidation of the luciferin resultin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undichna
''Undichna'' is a fish-fin, or fish-swimming fossil trail left as a fossil impression on a substrate, or the opposite impression on an overlying substrate; this type of fossil is an ichnofossil, in this case a specific ichnogenus, ''Undichna''; the term "undichna" is composed of the words: 'und'–'ichna', for "wave-trace". At present, the oldest known ''Undichna'' were made by cephalaspids, that only had presumptive motion scenarios, due to the physiological form of the cephalaspids as predating the teleosts, (bony fishes). The trails are from the border of England and Wales, from 400 mya, in an ancient riverbed environment. See also * Lateral undulation, a type of undulation for fish, sea animals, and snakes *Trace fossil *Fossil trackway A fossil track or ichnite ( Greek "''ιχνιον''" (''ichnion'') – a track, trace or footstep) is a fossilized footprint. This is a type of trace fossil. A fossil trackway is a sequence of fossil tracks left by a single organis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piscichnus
''Piscichnus'' is an ichnogenus of representing trace fossils A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of part ... associated with fish activities. ''Piscichnus'' is a large, plug-shaped trace fossil resembling foraging pits created by modern eagle rays. These fossils, found in shallow marine deposits, offer insights into the behavior and ecology of ancient fish. References External links Chuck D. Howell's Ichnogenera Photos Trace fossils {{trace-fossil-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichnotaxon
An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact. ''Ichnotaxon'' comes from the Ancient Greek (''íchnos'') meaning "track" and English , itself derived from Ancient Greek (''táxis'') meaning "ordering".Definition o'ichno'at dictionary.com. Ichnotaxa are names used to identify and distinguish morphologically distinctive ichnofossils, more commonly known as trace fossils (fossil records of lifeforms' movement, rather than of the lifeforms themselves). They are assigned genus and species ranks by ichnologists, much like organisms in Linnaean taxonomy. These are known as ichnogenera and ichnospecies, respectively. "Ichnogenus" and "ichnospecies" are commonly abbreviated as "igen." and "isp.". The binomial names of ichnospecies and their genera are to be written in italics. Most researchers classify trace fossils only as far as the ichnogenus rank, based upon trace fossils that resemble eac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoteleostei
The Neoteleostei is a large clade of teleostei, bony fish mostly consisting of marine clades. Only three lineages have freshwater species: Percopsiformes (Troutperches), which lives exclusively in freshwater, Gadiformes (cods), which is largely marine except from burbot that live in freshwater and a few populations of cod in brackish water, and the Percomorpha, which, in addition to several marine groups, also have many freshwater forms. The remaining members of Neoteleostei are marine: The populous clade of the Acanthopterygii which consist of the Beryciformes, Holocentridae and the aforementioned Percomorpha (which include families such as the Scombroidei, tuna, Syngnathiformes, seahorses, gobies, Cichlidae, cichlids, flatfish, Labridae, wrasse, Perciformes, perches, Lophiiformes, anglerfish, Tetraodontiformes, pufferfish), the Ateleopodidae (jellynoses), the Lampriformes (oarfish, opah, ribbonfish), the Zeiformes (dories), the Polymixiiformes (beardfish), the Stylephorus, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trace Fossil
A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of parts of organisms' bodies, usually altered by later chemical activity or by mineralization. The study of such trace fossils is ichnology - the work of ichnologists. Trace fossils may consist of physical impressions made on or in the substrate by an organism. For example, burrows, borings ( bioerosion), urolites (erosion caused by evacuation of liquid wastes), footprints, feeding marks, and root cavities may all be trace fossils. The term in its broadest sense also includes the remains of other organic material produced by an organism; for example coprolites (fossilized droppings) or chemical markers (sedimentological structures produced by biological means; for example, the formation of stromatolites). However, most sedimentary struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocephali
Holocephali (Sometimes spelled Holocephala; Romanization of Greek, Greek for "complete head" in reference to the fusion of Palatoquadrate, upper jaw with the rest of the skull) is a Subclass (biology), subclass of Chondrichthyes, cartilaginous fish. While the only living holocephalans are three families within a single Order (biology), order which together are commonly known as chimaeras, the group includes many extinct orders and was far more diverse during the Paleozoic and Mesozoic Era (geology), eras. The earliest known fossils of holocephalans date to the Middle Devonian period, and the group likely reached its peak diversity during the following Carboniferous period. Molecular clock studies suggest that the subclass diverged from its closest relatives, Elasmobranchii, elasmobranchs such as sharks and Batomorphi, rays, during the Early Devonian or Silurian period. Extinct holocephalans are typically divided into a number of orders, although the interrelationships of these gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flowering Plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit. The group was formerly called Magnoliophyta. Angiosperms are by far the most diverse group of Embryophyte, land plants with 64 Order (biology), orders, 416 Family (biology), families, approximately 13,000 known Genus, genera and 300,000 known species. They include all forbs (flowering plants without a woody Plant stem, stem), grasses and grass-like plants, a vast majority of broad-leaved trees, shrubs and vines, and most aquatic plants. Angiosperms are distinguished from the other major seed plant clade, the gymnosperms, by having flowers, xylem consisting of vessel elements instead of tracheids, endosperm within their seeds, and fruits that completely envelop the seeds. The ancestors of flowering plants diverged from the commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Jurassic
The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen 1987. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age. In the past, ''Malm'' was also used to indicate the unit of geological time, but this usage is now discouraged to make a clear distinction between lithostratigraphic and geochronologic/chronostratigraphic units. Subdivisions The Late Jurassic is divided into three ages, which correspond with the three (faunal) stages of Upper Jurassic rock: Paleogeography During the Late Jurassic Epoch, Pangaea broke up into two supercontinents, Laurasia to the north, and Gondwana to the south. The result of this break-up was the emergence of the Atlantic Ocean, which initially was relatively narrow. Life forms This epoch is well known for many famous types of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megapascal
The pascal (symbol: Pa) is the unit of pressure in the International System of Units (SI). It is also used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength. The unit, named after Blaise Pascal, is an SI coherent derived unit defined as one newton per square metre (N/m2). It is also equivalent to 10 barye (10 Ba) in the CGS system. Common multiple units of the pascal are the hectopascal (1 hPa = 100 Pa), which is equal to one millibar, and the kilopascal (1 kPa = 1000 Pa), which is equal to one centibar. The unit of measurement called '' standard atmosphere (atm)'' is defined as . Meteorological observations typically report atmospheric pressure in hectopascals per the recommendation of the World Meteorological Organization, thus a standard atmosphere (atm) or typical sea-level air pressure is about 1013 hPa. Reports in the United States typically use inches of mercury or millibars (hectopascals). In Canada, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmosphere (unit)
The standard atmosphere (symbol: atm) is a unit of pressure defined as Pa. It is sometimes used as a ''reference pressure'' or ''standard pressure''. It is approximately equal to Earth's average atmospheric pressure at sea level. History The standard atmosphere was originally defined as the pressure exerted by a 760 mm column of mercury at and standard gravity (''g''n = ). It was used as a reference condition for physical and chemical properties, and the definition of the centigrade temperature scale set 100 °C as the boiling point of water at this pressure. In 1954, the 10th General Conference on Weights and Measures (CGPM) adopted ''standard atmosphere'' for general use and affirmed its definition of being precisely equal to dynes per square centimetre (). This defined pressure in a way that is independent of the properties of any particular substance. In addition, the CGPM noted that there had been some misapprehension that the previous definition (from the 9th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
