1.
Eels (band)
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Eels music is often filled with themes about family, death and lost love. Since 1996, Eels has released studio albums, seven of which charted in the Billboard 200. In 1991, Everett signed a contract with Polydor and released A Man Called E under the name E a year later, the single Hello Cruel World was a minor success. Touring to support the album, E opened for Tori Amos, a Man Called E was followed by Broken Toy Shop in 1993. This year also marked the beginning of Es collaboration with drummer Jonathan Butch Norton, after Broken Toy Shop, E was released from his record deal with Polydor. E himself has recovered two of the songs from Broken Toy Shop for his own shows with the Eels. Eels were officially founded when Butch and E met Tommy Walter, Eels became one of the first groups to sign a record deal with DreamWorks Records, followed by Elliott Smith. In 1996, the released their debut album Beautiful Freak. In 1996 and 1997, Eels toured extensively to support the album, building their name as an act in the United States. In September 1997, Walter quit the band, following the success of Beautiful Freak, E experienced a difficult time in his personal life. His sister committed suicide, and his mother was diagnosed with cancer and these events inspired him to write Electro-Shock Blues, which focuses on his family, which he had never written about previously. Electro-Shock Blues was released in 1998, the album deals with many difficult subjects including suicide, death, and cancer. Contributions to the album were made by Jon Brion, Lisa Germano, Grant-Lee Phillips, Dust Brother Michael Simpson, the single Last Stop, This Town saw minor success, Cancer for the Cure, the second single from the album, was used on the American Beauty soundtrack. Still a three-piece band on stage, Tommy Walter was replaced by Adam Siegel, part of the American leg of the tour was cancelled after the death of Es mother. They returned to tour Europe later in the year, to open for Pulp, in 2000, Eels released Daisies of the Galaxy. The album, which was recorded almost entirely in Es basement, is lighter and he was joined in the studio by Michael Simpson, Grant-Lee Phillips, and Peter Buck. The first single, Mr. Es Beautiful Blues, was co-written by Simpson, the song was not intended to be on the album, but the record company insisted on its inclusion. Therefore, it is not featured on the listing but is instead listed as a bonus track
2.
Precambrian
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The Precambrian is the earliest period of Earths history, set before the current Phanerozoic Eon. The Precambrian is a supereon that is subdivided into three eons of the time scale. It spans from the formation of Earth about 4.6 billion years ago to the beginning of the Cambrian Period, about 541 million years ago, the Precambrian accounts for 89% of geologic time. Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earths history, the Precambrian fossil record is poorer than that of the succeeding Phanerozoic, and fossils from that time are of limited biostratigraphic use. This is because many Precambrian rocks have been metamorphosed, obscuring their origins, while others have been destroyed by erosion. A stable crust was apparently in place by 4,412 Ma, the term Precambrian is recognized by the International Commission on Stratigraphy as a general term including the Archean and Proterozoic eons. It is still used by geologists and paleontologists for general discussions not requiring the more specific eon names and it was briefly called the Cryptozoic eon. A specific date for the origin of life has not been determined, carbon found in 3.8 billion year old rocks from islands off western Greenland may be of organic origin. Well-preserved microscopic fossils of bacteria older than 3.46 billion years have found in Western Australia. Probable fossils 100 million years older have been found in the same area, there is a fairly solid record of bacterial life throughout the remainder of the Precambrian. The oldest fossil evidence from that era of such complex life comes from the Lantian formation of the Ediacarian period, a very diverse collection of soft-bodied forms is found in a variety of locations worldwide and date to between 635 and 542 Ma. These are referred to as Ediacaran or Vendian biota, hard-shelled creatures appeared toward the end of that time span, marking the beginning of the Phanerozoic era. By the middle of the following Cambrian period, a diverse fauna is recorded in the Burgess Shale. The explosion in diversity of lifeforms during the early Cambrian is called the Cambrian explosion of life, while land seems to have been devoid of plants and animals, cyanobacteria and other microbes formed prokaryotic mats that covered terrestrial areas. Evidence of the details of plate motions and other activity in the Precambrian has been poorly preserved. It is generally believed that small proto-continents existed prior to 4280 Ma, the supercontinent, known as Rodinia, broke up around 750 Ma. A number of glacial periods have been identified going as far back as the Huronian epoch, one of the best studied is the Sturtian-Varangian glaciation, around 850–635 Ma, which may have brought glacial conditions all the way to the equator, resulting in a Snowball Earth. The atmosphere of the early Earth is not well understood, most geologists believe it was composed primarily of nitrogen, carbon dioxide, and other relatively inert gases, and was lacking in free oxygen
3.
Cambrian
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The Cambrian Period was the first geological period of the Paleozoic Era, of the Phanerozoic Eon. The Cambrian lasted 55.6 million years from the end of the preceding Ediacaran Period 541 million years ago to the beginning of the Ordovician Period 485.4 mya and its subdivisions, and its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latinised form of Cymru, the Welsh name for Wales, as a result, our understanding of the Cambrian biology surpasses that of some later periods. The rapid diversification of lifeforms in the Cambrian, known as the Cambrian explosion, most of the continents were probably dry and rocky due to a lack of vegetation. Shallow seas flanked the margins of several continents created during the breakup of the supercontinent Pannotia, the seas were relatively warm, and polar ice was absent for much of the period. The United States Federal Geographic Data Committee uses a barred capital C ⟨Є⟩ character similar to the capital letter Ukrainian Ye ⟨Є⟩ to represent the Cambrian Period, the proper Unicode character is U+A792 Ꞓ LATIN CAPITAL LETTER C WITH BAR. Despite the long recognition of its distinction from younger Ordovician Period rocks and older Supereon Precambrian rocks, the base of the Cambrian lies atop a complex assemblage of trace fossils known as the Treptichnus pedum assemblage. Pedum in Namibia, Spain and Newfoundland, and possibly, in the western USA, the stratigraphic range of T. pedum overlaps the range of the Ediacaran fossils in Namibia, and probably in Spain. The Cambrian Period followed the Ediacaran Period and was followed by the Ordovician Period, the Cambrian is divided into four epochs and ten ages. Currently only two series and five stages are named and have a GSSP, because the international stratigraphic subdivision is not yet complete, many local subdivisions are still widely used. In some of these subdivisions the Cambrian is divided into three epochs with locally differing names – the Early Cambrian, Middle Cambrian and Furongian, rocks of these epochs are referred to as belonging to the Lower, Middle, or Upper Cambrian. Trilobite zones allow biostratigraphic correlation in the Cambrian, each of the local epochs is divided into several stages. The International Commission on Stratigraphy list the Cambrian period as beginning at 541 million years ago, the lower boundary of the Cambrian was originally held to represent the first appearance of complex life, represented by trilobites. The recognition of small shelly fossils before the first trilobites, and Ediacara biota substantially earlier and this formal designation allowed radiometric dates to be obtained from samples across the globe that corresponded to the base of the Cambrian. Early dates of 570 million years ago quickly gained favour, though the used to obtain this number are now considered to be unsuitable. A more precise date using modern radiometric dating yield a date of 541 ±0.3 million years ago, most continental land was clustered in the Southern Hemisphere at this time, but was drifting north. Large, high-velocity rotational movement of Gondwana appears to have occurred in the Early Cambrian, the sea levels fluctuated somewhat, suggesting there were ice ages, associated with pulses of expansion and contraction of a south polar ice cap. In Baltoscandia a Lower Cambrian transgression transformed large swathes of the Sub-Cambrian peneplain into a epicontinental sea, the Earth was generally cold during the early Cambrian, probably due to the ancient continent of Gondwana covering the South Pole and cutting off polar ocean currents
4.
Ordovician
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The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.2 million years from the end of the Cambrian Period 485.4 million years ago to the start of the Silurian Period 443.8 Mya. Lapworth recognized that the fauna in the disputed strata were different from those of either the Cambrian or the Silurian periods. It received international sanction in 1960, when it was adopted as a period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian period, invertebrates, namely molluscs and arthropods, dominated the oceans. The Great Ordovician Biodiversification Event considerably increased the diversity of life, fish, the worlds first true vertebrates, continued to evolve, and those with jaws may have first appeared late in the period. Life had yet to diversify on land, about 100 times as many meteorites struck the Earth during the Ordovician compared with today. The Ordovician Period began with a major extinction called the Cambrian–Ordovician extinction event and it lasted for about 42 million years and ended with the Ordovician–Silurian extinction event, about 443.8 Mya which wiped out 60% of marine genera. The dates given are recent radiometric dates and vary slightly from those found in other sources and this second period of the Paleozoic era created abundant fossils that became major petroleum and gas reservoirs. The boundary chosen for the beginning of both the Ordovician Period and the Tremadocian stage is highly significant and it correlates well with the occurrence of widespread graptolite, conodont, and trilobite species. The base of the Tremadocian allows scientists to relate these species not only to each other and this makes it easier to place many more species in time relative to the beginning of the Ordovician Period. A number of terms have been used to subdivide the Ordovician Period. In 2008, the ICS erected an international system of subdivisions. There exist Baltoscandic, British, Siberian, North American, Australian, the Ordovician Period in Britain was traditionally broken into Early, Middle and Late epochs. The corresponding rocks of the Ordovician System are referred to as coming from the Lower, Middle, the Floian corresponds to the lower Arenig, the Arenig continues until the early Darriwilian, subsuming the Dapingian. The Llanvirn occupies the rest of the Darriwilian, and terminates with it at the base of the Late Ordovician. The Sandbian represents the first half of the Caradoc, the Caradoc ends in the mid-Katian, during the Ordovician, the southern continents were collected into Gondwana. Gondwana started the period in equatorial latitudes and, as the period progressed, drifted toward the South Pole, the small continent Avalonia separated from Gondwana and began to move north towards Baltica and Laurentia, opening the Rheic Ocean between Gondwana and Avalonia
5.
Silurian
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The Silurian is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago, to the beginning of the Devonian Period,419.2 Mya. As with other periods, the rock beds that define the periods start and end are well identified. The base of the Silurian is set at a major Ordovician-Silurian extinction event when 60% of marine species were wiped out, a significant evolutionary milestone during the Silurian was the diversification of jawed and bony fish. However, terrestrial life would not greatly diversify and affect the landscape until the Devonian, the Silurian system was first identified by British geologist Sir Roderick Impey Murchison, who was examining fossil-bearing sedimentary rock strata in south Wales in the early 1830s. He named the sequences for a Celtic tribe of Wales, the Silures, inspired by his friend Adam Sedgwick and this naming does not indicate any correlation between the occurrence of the Silurian rocks and the land inhabited by the Silures. As it was first identified, the Silurian series when traced farther afield quickly came to overlap Sedgwicks Cambrian sequence, however, charles Lapworth resolved the conflict by defining a new Ordovician system including the contested beds. An early alternative name for the Silurian was Gotlandian after the strata of the Baltic island of Gotland, the French geologist Joachim Barrande, building on Murchisons work, used the term Silurian in a more comprehensive sense than was justified by subsequent knowledge. He divided the Silurian rocks of Bohemia into eight stages and his interpretation was questioned in 1854 by Edward Forbes, and the later stages of Barrande, F, G and H, have since been shown to be Devonian. Despite these modifications in the groupings of the strata, it is recognized that Barrande established Bohemia as a classic ground for the study of the earliest fossils. The epoch is named for the town of Llandovery in Carmarthenshire, the Wenlock, which lasted from 433.4 ±1.5 to 427.4 ±2.8 mya, is subdivided into the Sheinwoodian and Homerian ages. It is named after Wenlock Edge in Shropshire, England, during the Wenlock, the oldest known tracheophytes of the genus Cooksonia, appear. The first terrestrial animals also appear in the Wenlock, represented by air-breathing millipedes from Scotland. The Ludlow, lasting from 427.4 ±1.5 to 423 ±2.8 mya, comprises the Gorstian stage, lasting until 425.6 million years ago, and it is named for the town of Ludlow in Shropshire, England. The Pridoli, lasting from 423 ±1.5 to 419.2 ±2.8 mya, is the final and it is named after one locality at the Homolka a Přídolí nature reserve near the Prague suburb Slivenec in the Czech Republic. Přídolí is the old name of a field area. The high sea levels of the Silurian and the flat land resulted in a number of island chains. The southern continents remained united during this period, the melting of icecaps and glaciers contributed to a rise in sea level, recognizable from the fact that Silurian sediments overlie eroded Ordovician sediments, forming an unconformity. The continents of Avalonia, Baltica, and Laurentia drifted together near the equator and this event is the Caledonian orogeny, a spate of mountain building that stretched from New York State through conjoined Europe and Greenland to Norway
6.
Devonian
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The Devonian is a geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian,419.2 million years ago, to the beginning of the Carboniferous,358.9 Mya. It is named after Devon, England, where rocks from this period were first studied, the first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents, by the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. Various terrestrial arthropods also became well-established, Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fish. The first ray-finned and lobe-finned bony fish appeared, while the placodermi began dominating almost every aquatic environment. The ancestors of all four-limbed vertebrates began adapting to walking on land, as their strong pectoral, in the oceans, primitive sharks became more numerous than in the Silurian and Late Ordovician. The first ammonites, species of molluscs, appeared, trilobites, the mollusk-like brachiopods and the great coral reefs, were still common. The Late Devonian extinction which started about 375 million years ago severely affected marine life, killing off all placodermi, and all trilobites, save for a few species of the order Proetida. The palaeogeography was dominated by the supercontinent of Gondwana to the south, the continent of Siberia to the north, while the rock beds that define the start and end of the Devonian period are well identified, the exact dates are uncertain. According to the International Commission on Stratigraphy, the Devonian extends from the end of the Silurian 419.2 Mya, another common term is Age of the Fishes, referring to the evolution of several major groups of fish that took place during the period. Older literature on the Anglo-Welsh basin divides it into the Downtonian, Dittonian, Breconian and Farlovian stages, in the Late Devonian, by contrast, arid conditions were less prevalent across the world and temperate climates were more common. The Devonian Period is formally broken into Early, Middle and Late subdivisions, the rocks corresponding to those epochs are referred to as belonging to the Lower, Middle and Upper parts of the Devonian System. Early Devonian The Early Devonian lasted from 419.2 ±2.8 to 393.3 ±2.5 and began with the Lochkovian stage, which lasted until the Pragian. It spanned from 410.8 ±2.8 to 407.6 ±2.5, and was followed by the Emsian, which lasted until the Middle Devonian began,393. 3±2.7 million years ago. Middle Devonian The Middle Devonian comprised two subdivisions, first the Eifelian, which gave way to the Givetian 387. 7±2.7 million years ago. Late Devonian Finally, the Late Devonian started with the Frasnian,382.7 ±2.8 to 372.2 ±2.5, during which the first forests took shape on land. The first tetrapods appeared in the record in the ensuing Famennian subdivision. This lasted until the end of the Devonian,358. 9±2.5 million years ago, the Devonian was a relatively warm period, and probably lacked any glaciers
7.
Carboniferous
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The Carboniferous is a geologic period and system that spans 60 million years from the end of the Devonian Period 358.9 million years ago, to the beginning of the Permian Period,298.9 Mya. The name Carboniferous means coal-bearing and derives from the Latin words carbō and ferō, and was coined by geologists William Conybeare and William Phillips in 1822. Based on a study of the British rock succession, it was the first of the system names to be employed. The Carboniferous is often treated in North America as two periods, the earlier Mississippian and the later Pennsylvanian. Terrestrial life was established by the Carboniferous period. Amphibians were the dominant land vertebrates, of one branch would eventually evolve into amniotes. Arthropods were also common, and many were much larger than those of today. Vast swaths of forest covered the land, which would eventually be laid down, the atmospheric content of oxygen also reached their highest levels in geological history during the period, 35% compared with 21% today, allowing terrestrial invertebrates to evolve to great size. A major marine and terrestrial extinction event, the Carboniferous rainforest collapse, occurred in the middle of the period, the later half of the period experienced glaciations, low sea level, and mountain building as the continents collided to form Pangaea. In the United States the Carboniferous is usually broken into Mississippian and Pennsylvanian subperiods, the Silesian is roughly contemporaneous with the late Mississippian Serpukhovian plus the Pennsylvanian. In Britain the Dinantian is traditionally known as the Carboniferous Limestone, the Namurian as the Millstone Grit, and the Westphalian as the Coal Measures and Pennant Sandstone. There was also a drop in south polar temperatures, southern Gondwanaland was glaciated throughout the period and these conditions apparently had little effect in the deep tropics, where lush swamps, later to become coal, flourished to within 30 degrees of the northernmost glaciers. Mid-Carboniferous, a drop in sea level precipitated a major extinction, one that hit crinoids. This sea level drop and the unconformity in North America separate the Mississippian subperiod from the Pennsylvanian subperiod. This happened about 323 million years ago, at the onset of the Permo-Carboniferous Glaciation, the Carboniferous was a time of active mountain-building, as the supercontinent Pangaea came together. The southern continents remained tied together in the supercontinent Gondwana, which collided with North America–Europe along the present line of eastern North America, in the same time frame, much of present eastern Eurasian plate welded itself to Europe along the line of the Ural mountains. Most of the Mesozoic supercontinent of Pangea was now assembled, although North China, the Late Carboniferous Pangaea was shaped like an O. There were two major oceans in the Carboniferous—Panthalassa and Paleo-Tethys, which was inside the O in the Carboniferous Pangaea, other minor oceans were shrinking and eventually closed - Rheic Ocean, the small, shallow Ural Ocean and Proto-Tethys Ocean
8.
Permian
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The Permian is a geologic period and system which spans 46.7 million years from the end of the Carboniferous Period 298.9 million years ago, to the beginning of the Triassic Period 252.2 Mya. It is the last period of the Paleozoic Era, the following Triassic Period belongs to the Mesozoic Era, the concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the city of Perm. The Permian witnessed the diversification of the early amniotes into the groups of the mammals, turtles, lepidosaurs. The world at the time was dominated by two known as Pangaea and Siberia, surrounded by a global ocean called Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior, amniotes, who could better cope with these drier conditions, rose to dominance in place of their amphibian ancestors. The Permian ended with the Permian–Triassic extinction event, the largest mass extinction in Earths history, in which nearly 90% of marine species and it would take well into the Triassic for life to recover from this catastrophe. Recovery from the Permian-Triassic extinction event was protracted, on land, the term Permian was introduced into geology in 1841 by Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil, the region now lies in the Perm Krai of Russia. This could have in part caused the extinctions of marine species at the end of the period by severely reducing shallow coastal areas preferred by many marine organisms. During the Permian, all the Earths major landmasses were collected into a supercontinent known as Pangaea. The Cimmeria continent rifted away from Gondwana and drifted north to Laurasia, a new ocean was growing on its southern end, the Tethys Ocean, an ocean that would dominate much of the Mesozoic Era. Large continental landmass interiors experience climates with extreme variations of heat and cold, deserts seem to have been widespread on Pangaea. Such dry conditions favored gymnosperms, plants with seeds enclosed in a cover, over plants such as ferns that disperse spores in a wetter environment. The first modern trees appeared in the Permian, the climate in the Permian was quite varied. At the start of the Permian, the Earth was still in an Ice Age, glaciers receded around the mid-Permian period as the climate gradually warmed, drying the continents interiors. In the late Permian period, the drying continued although the temperature cycled between warm and cool cycles, Permian marine deposits are rich in fossil mollusks, echinoderms, and brachiopods. By the close of the Permian, trilobites and a host of other groups became extinct. Terrestrial life in the Permian included diverse plants, fungi, arthropods, the period saw a massive desert covering the interior of Pangaea
9.
Triassic
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The Triassic is a geologic period and system which spans 50.9 million years from the end of the Permian Period 252.17 million years ago, to the beginning of the Jurassic Period 201.3 Mya. The Triassic is the first period of the Mesozoic Era, both the start and end of the period are marked by major extinction events. Therapsids and archosaurs were the terrestrial vertebrates during this time. A specialized subgroup of archosaurs, called dinosaurs, first appeared in the Late Triassic, the vast supercontinent of Pangaea existed until the mid-Triassic, after which it began to gradually rift into two separate landmasses, Laurasia to the north and Gondwana to the south. The global climate during the Triassic was mostly hot and dry, however, the climate shifted and became more humid as Pangaea began to drift apart. The end of the period was marked by yet another mass extinction, the Triassic-Jurassic extinction event. The Triassic is usually separated into Early, Middle, and Late Triassic Epochs, from the east, along the equator, the Tethys sea penetrated Pangaea, causing the Paleo-Tethys Ocean to be closed. Later in the mid-Triassic a similar sea penetrated along the equator from the west, the remaining shores were surrounded by the world-ocean known as Panthalassa. All the deep-ocean sediments laid down during the Triassic have disappeared through subduction of oceanic plates, thus, the supercontinent Pangaea was rifting during the Triassic—especially late in that period—but had not yet separated. In North America, for example, marine deposits are limited to a few exposures in the west, thus Triassic stratigraphy is mostly based on organisms that lived in lagoons and hypersaline environments, such as Estheria crustaceans. At the beginning of the Mesozoic Era, Africa was joined with Earths other continents in Pangaea, Africa shared the supercontinents relatively uniform fauna which was dominated by theropods, prosauropods and primitive ornithischians by the close of the Triassic period. Late Triassic fossils are found throughout Africa, but are common in the south than north. The time boundary separating the Permian and Triassic marks the advent of an event with global impact. At Paleorrota geopark, located in Rio Grande do Sul, Brazil, in these formations, one of the earliest dinosaurs, Staurikosaurus, as well as the mammal ancestors Brasilitherium and Brasilodon have been discovered. The Triassic continental interior climate was hot and dry, so that typical deposits are red bed sandstones and evaporites. Pangaeas large size limited the effect of the global ocean, its continental climate was highly seasonal, with very hot summers. The strong contrast between the Pangea supercontinent and the global ocean triggered intense cross-equatorial monsoons, the best studied of such episodes of humid climate, and probably the most intense and widespread, was the Carnian Pluvial Event. On land, the vascular plants included the lycophytes, the dominant cycadophytes, ginkgophyta, ferns, horsetails
10.
Jurassic
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The Jurassic is a geologic period and system that spans 56.3 million years from the end of the Triassic Period 201.3 million years ago to the beginning of the Cretaceous Period 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era, also known as the Age of Reptiles, the start of the period is marked by the major Triassic–Jurassic extinction event. The Jurassic is named after the Jura Mountains within the European Alps, by the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses, Laurasia to the north and Gondwana to the south. This created more coastlines and shifted the continental climate from dry to humid, on land, the fauna transitioned from the Triassic fauna, dominated by both dinosauromorph and crocodylomorph archosaurs, to one dominated by dinosaurs alone. The first birds also appeared during the Jurassic, having evolved from a branch of theropod dinosaurs, other major events include the appearance of the earliest lizards, and the evolution of therian mammals, including primitive placentals. Crocodilians made the transition from a terrestrial to a mode of life. The oceans were inhabited by marine reptiles such as ichthyosaurs and plesiosaurs, the chronostratigraphic term Jurassic is directly linked to the Jura Mountains. The name Jura is derived from the Celtic root jor, which was Latinised into juria, the Jurassic period is divided into the Early Jurassic, Middle, and Late Jurassic epochs. The Jurassic System, in stratigraphy, is divided into the Lower Jurassic, Middle, the separation of the term Jurassic into three sections goes back to Leopold von Buch. The Jurassic North Atlantic Ocean was relatively narrow, while the South Atlantic did not open until the following Cretaceous period, the Tethys Sea closed, and the Neotethys basin appeared. Climates were warm, with no evidence of glaciation, as in the Triassic, there was apparently no land over either pole, and no extensive ice caps existed. In contrast, the North American Jurassic record is the poorest of the Mesozoic, the Jurassic was a time of calcite sea geochemistry in which low-magnesium calcite was the primary inorganic marine precipitate of calcium carbonate. Carbonate hardgrounds were thus very common, along with calcitic ooids, calcitic cements, the first of several massive batholiths were emplaced in the northern American cordillera beginning in the mid-Jurassic, marking the Nevadan orogeny. Important Jurassic exposures are found in Russia, India, South America, Japan, Australasia. As the Jurassic proceeded, larger and more groups of dinosaurs like sauropods and ornithopods proliferated in Africa. Middle Jurassic strata are well represented nor well studied in Africa. Late Jurassic strata are also poorly represented apart from the spectacular Tendaguru fauna in Tanzania, the Late Jurassic life of Tendaguru is very similar to that found in western North Americas Morrison Formation. During the Jurassic period, the primary living in the sea were fish
11.
Cretaceous
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The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period 145 million years ago to the beginning of the Paleogene Period 66 Mya. It is the last period of the Mesozoic Era, the Cretaceous Period is usually abbreviated K, for its German translation Kreide. The Cretaceous was a period with a warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites and rudists, during this time, new groups of mammals and birds, as well as flowering plants, appeared. The Cretaceous ended with a mass extinction, the Cretaceous–Paleogene extinction event, in which many groups, including non-avian dinosaurs, pterosaurs. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary, the name Cretaceous was derived from Latin creta, meaning chalk. The Cretaceous is divided into Early and Late Cretaceous epochs, or Lower and Upper Cretaceous series, in older literature the Cretaceous is sometimes divided into three series, Neocomian, Gallic and Senonian. A subdivision in eleven stages, all originating from European stratigraphy, is now used worldwide, in many parts of the world, alternative local subdivisions are still in use. As with other geologic periods, the rock beds of the Cretaceous are well identified. No great extinction or burst of diversity separates the Cretaceous from the Jurassic and this layer has been dated at 66.043 Ma. A140 Ma age for the Jurassic-Cretaceous boundary instead of the usually accepted 145 Ma was proposed in 2014 based on a study of Vaca Muerta Formation in Neuquén Basin. Víctor Ramos, one of the authors of the study proposing the 140 Ma boundary age sees the study as a first step toward formally changing the age in the International Union of Geological Sciences, due to the high sea level there was extensive space for such sedimentation. Because of the young age and great thickness of the system. Chalk is a type characteristic for the Cretaceous. It consists of coccoliths, microscopically small calcite skeletons of coccolithophores, the group is found in England, northern France, the low countries, northern Germany, Denmark and in the subsurface of the southern part of the North Sea. Chalk is not easily consolidated and the Chalk Group still consists of sediments in many places. The group also has other limestones and arenites, among the fossils it contains are sea urchins, belemnites, ammonites and sea reptiles such as Mosasaurus. In southern Europe, the Cretaceous is usually a marine system consisting of competent limestone beds or incompetent marls
12.
Paleogene
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The Paleogene is a geologic period and system that spans 43 million years from the end of the Cretaceous Period 66 million years ago to the beginning of the Neogene Period 23.03 Mya. It is the beginning of the Cenozoic Era of the present Phanerozoic Eon and this period consists of the Paleocene, Eocene and Oligocene epochs. The terms Paleogene System and lower Tertiary System are applied to the rocks deposited during the Paleogene Period. By dividing the Tertiary Period into two periods instead of directly into five epochs, the periods are more comparable to the duration of periods of the preceding Mesozoic and Paleozoic Eras. The trend was caused by the formation of the Antarctic Circumpolar Current. During the Paleogene, the continued to drift closer to their current positions. India was in the process of colliding with Asia, subsequently forming the Himalayas, the Atlantic Ocean continued to widen by a few centimeters each year. Africa was moving north to meet with Europe and form the Mediterranean, inland seas retreated from North America early in the period. Australia had also separated from Antarctica and was drifting towards Southeast Asia, mammals began a rapid diversification during this period. Some of these mammals would evolve into forms that would dominate the land, while others would become capable of living in marine, specialized terrestrial. Those that took to the oceans became modern cetaceans, while those that took to the trees became primates, the group to which humans belong. Birds, which were well established by the end of the Cretaceous. In comparison to birds and mammals, most other branches of life remained unchanged during this period. As the Earth cooled, tropical plants became less numerous and were now restricted to equatorial regions, deciduous plants, which could survive through the seasonal climates the world was now experiencing, became more common. The Paleogene is notable in the context of offshore oil drilling, and especially in Gulf of Mexico oil exploration and these rock formations represent the current cutting edge of deep-water oil discovery. Lower Tertiary explorations to date include, Kaskida Oil Field Tiber Oil Field Jack 2 Paleogene Microfossils, 180+ images of Foraminifera
13.
Neogene
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The Neogene is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period 23.03 million years ago to the beginning of the present Quaternary Period 2.58 Mya. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene, some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. During this period, mammals and birds continued to evolve into modern forms. Early hominids, the ancestors of humans, appeared in Africa near the end of the period, some continental movement took place, the most significant event being the connection of North and South America at the Isthmus of Panama, late in the Pliocene. This cut off the ocean currents from the Pacific to the Atlantic ocean. The global climate cooled considerably over the course of the Neogene, the terms Neogene System and upper Tertiary System describe the rocks deposited during the Neogene Period. The continents in the Neogene were very close to their current positions, the Isthmus of Panama formed, connecting North and South America. The Indian subcontinent continued to collide with Asia, forming the Himalayas, sea levels fell, creating land bridges between Africa and Eurasia and between Eurasia and North America. The global climate became seasonal and continued an overall drying and cooling trend which began at the start of the Paleogene. The ice caps on both poles began to grow and thicken, and by the end of the period the first of a series of glaciations of the current Ice Age began, marine and continental flora and fauna have a modern appearance. The reptile group Choristodera became extinct in the part of the period. Mammals and birds continued to be the dominant terrestrial vertebrates, the first hominids, the ancestors of humans, appeared in Africa and spread into Eurasia. In response to the cooler, seasonal climate, tropical plant species gave way to deciduous ones, grasses therefore greatly diversified, and herbivorous mammals evolved alongside it, creating the many grazing animals of today such as horses, antelope, and bison. The Neogene traditionally ended at the end of the Pliocene Epoch, just before the definition of the beginning of the Quaternary Period. However, there was a movement amongst geologists to also include ongoing geological time in the Neogene, by dividing the Cenozoic Era into three periods instead of seven epochs, the periods are more closely comparable to the duration of periods in the Mesozoic and Paleozoic eras. The International Commission on Stratigraphy once proposed that the Quaternary be considered a sub-era of the Neogene, with a date of 2.58 Ma. In the 2004 proposal of the ICS, the Neogene would have consisted of the Miocene and Pliocene epochs, thus the Neogene Period ends bounding the succeeding Quaternary Period at 2.58 Mya. Digital Atlas of Neogene Life for the Southeastern United States — by San Jose State University via Web Archive
14.
Japanese eel
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The Japanese eel is a species of anguillid eel found in Japan, Korea, China, Taiwan, and Vietnam, as well as the northern Philippines. Like all the eels of the genus Anguilla and the family Anguillidae, it is catadromous, meaning it spawns in the sea, the spawning area of this species is in the North Equatorial Current in the western North Pacific to the west of the Mariana Islands. The larvae are called leptocephali and are carried westward by the North Equatorial Current and then northward by the Kuroshio Current to East Asia, where they live in rivers, lakes, and estuaries. The Japanese eel is an important food fish in East Asia, in Japan, where they are called unagi, they are an important part of the food culture, with many restaurants serving grilled eel, which is called kabayaki. Eels also have uses in Chinese medicine, the Japanese eel and other anguillid eels live in fresh water and estuaries where they feed and grow as yellow eels for a number of years before they begin to mature and become silver eels. The silver eels then migrate out of water into the ocean. Adult Japanese eels migrate thousands of kilometers from freshwater rivers in East Asia to their spawning area without feeding, in more recent years, more preleptocephali have been collected, and even Japanese eel eggs have been collected and genetically identified at sea on the research vessel. The collections of eggs and recently hatched larvae have been made along the side of the seamount chain of the West Mariana Ridge. Furthermore, mature adults of the Japanese eel and giant mottled eel were captured using large midwater trawls in 2008 by Japanese scientists at the Fisheries Research Agency. The adults of the Japanese eel appear to spawn in the few hundred meters of the ocean based on the recent catches of their spawning adults, eggs. After hatching in the ocean, the leptocephali are carried westward by the North Equatorial Current, in the open ocean, the larvae feed on marine snow, before they metamorphose into the glass eel stage. The glass eels then enter the estuaries and headwaters of rivers, in fresh water and estuaries, the diet of yellow eels consists mainly of shrimp, other crustaceans, aquatic insects, and small fishes. In the case of the Japanese eel, spawning is likely affected by the shifts of a salinity front created by an area of low-salinity waters resulting from tropical rainfall. The front is thought to be detected by the adult spawning eels and these types of unfavorable larval transport are thought to reduce the recruitment success of the Japanese eels that reach river mouths as glass eels. The Japanese freshwater eel is the only known to produce a fluorescent protein. This protein is the basis of a new test to assess dangerous blood toxins that can trigger liver disease
15.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
16.
Animal
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Animals are multicellular, eukaryotic organisms of the kingdom Animalia. The animal kingdom emerged as a clade within Apoikozoa as the group to the choanoflagellates. Animals are motile, meaning they can move spontaneously and independently at some point in their lives and their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs, they must ingest other organisms or their products for sustenance, most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago. Animals can be divided broadly into vertebrates and invertebrates, vertebrates have a backbone or spine, and amount to less than five percent of all described animal species. They include fish, amphibians, reptiles, birds and mammals, the remaining animals are the invertebrates, which lack a backbone. These include molluscs, arthropods, annelids, nematodes, flatworms, cnidarians, ctenophores, the study of animals is called zoology. The word animal comes from the Latin animalis, meaning having breath, the biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects, and humans. Aristotle divided the world between animals and plants, and this was followed by Carl Linnaeus, in the first hierarchical classification. In Linnaeuss original scheme, the animals were one of three kingdoms, divided into the classes of Vermes, Insecta, Pisces, Amphibia, Aves, and Mammalia. Since then the last four have all been subsumed into a single phylum, in 1874, Ernst Haeckel divided the animal kingdom into two subkingdoms, Metazoa and Protozoa. The protozoa were later moved to the kingdom Protista, leaving only the metazoa, thus Metazoa is now considered a synonym of Animalia. Animals have several characteristics that set apart from other living things. Animals are eukaryotic and multicellular, which separates them from bacteria and they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae. They are also distinguished from plants, algae, and fungi by lacking cell walls. All animals are motile, if only at life stages. In most animals, embryos pass through a stage, which is a characteristic exclusive to animals. With a few exceptions, most notably the sponges and Placozoa and these include muscles, which are able to contract and control locomotion, and nerve tissues, which send and process signals
17.
Chordate
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Chordates are deuterostomes, as during the embryo development stage the anus forms before the mouth. They are also bilaterally symmetric coelomates, in the case of vertebrate chordates, the notochord is usually replaced by a vertebral column during development, and they may have body plans organized via segmentation. There are also additional extinct taxa, the Vertebrata are sometimes considered as a subgroup of the clade Craniata, consisting of chordates with a skull, the Craniata and Tunicata compose the clade Olfactores. Of the more than 65,000 living species of chordates, the worlds largest and fastest animals, the blue whale and peregrine falcon respectively, are chordates, as are humans. Fossil chordates are known from at least as early as the Cambrian explosion, Hemichordata, which includes the acorn worms, has been presented as a fourth chordate subphylum, but it now is usually treated as a separate phylum. The Hemichordata, along with the Echinodermata, form the Ambulacraria, the Chordata and Ambulacraria form the superphylum Deuterostomia, composed of the deuterostomes. Attempts to work out the relationships of the chordates have produced several hypotheses. All of the earliest chordate fossils have found in the Early Cambrian Chengjiang fauna. Because the fossil record of early chordates is poor, only molecular phylogenetics offers a prospect of dating their emergence. However, the use of molecular phylogenetics for dating evolutionary transitions is controversial and it has also proved difficult to produce a detailed classification within the living chordates. Attempts to produce family trees shows that many of the traditional classes are paraphyletic. While this has been known since the 19th century, an insistence on only monophyletic taxa has resulted in vertebrate classification being in a state of flux. Although the name Chordata is attributed to William Bateson, it was already in prevalent use by 1880, ernst Haeckel described a taxon comprising tunicates, cephalochordates, and vertebrates in 1866. Though he used the German vernacular form, it is allowed under the ICZN code because of its subsequent latinization, among the vertebrate sub-group of chordates the notochord develops into the spine, and in wholly aquatic species this helps the animal to swim by flexing its tail. In fish and other vertebrates, this develops into the spinal cord, the pharynx is the part of the throat immediately behind the mouth. In fish, the slits are modified to form gills, a muscular tail that extends backwards behind the anus. This is a groove in the wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus and it also stores iodine, and may be a precursor of the vertebrate thyroid gland
18.
Actinopterygii
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Actinopterygii /ˌæktᵻnˌɒptəˈrɪdʒi. aɪ/, or the ray-finned fishes, constitute a class or subclass of the bony fishes. These actinopterygian fin rays attach directly to the proximal or basal skeletal elements, the radials, numerically, actinopterygians are the dominant class of vertebrates, comprising nearly 99% of the over 30,000 species of fish. They are ubiquitous throughout freshwater and marine environments from the sea to the highest mountain streams. Extant species can range in size from Paedocypris, at 8 mm, to the ocean sunfish, at 2,300 kg. Ray-finned fishes occur in variant forms. The main features of a typical ray-finned fish are shown in the diagram at the left. In nearly all ray-finned fish, the sexes are separate, development then proceeds with a free-swimming larval stage. However other patterns of ontogeny exist, with one of the commonest being sequential hermaphroditism, in most cases this involves protogyny, fish starting life as females and converting to males at some stage, triggered by some internal or external factor. This may be advantageous as females become less prolific as they age while male fecundity increases with age, protandry, where a fish converts from male to female, is much less common than protogyny. Most families use external rather than internal fertilization, of the oviparous teleosts, most do not provide parental care. Viviparity is relatively rare and is found in about 6% of teleost species, male territoriality preadapts a species for evolving male parental care. There are a few examples of fish that self-fertilise, the mangrove rivulus is an amphibious, simultaneous hermaphrodite, producing both eggs and spawn and having internal fertilisation. This mode of reproduction may be related to the habit of spending long periods out of water in the mangrove forests it inhabits. Males are occasionally produced at temperatures below 19 °C and can fertilise eggs that are spawned by the female. This maintains genetic variability in a species that is otherwise highly inbred, the earliest known fossil actinopterygiian is Andreolepis hedei, dating back 420 million years. Remains have been found in Russia, Sweden, and Estonia, actinopterygians are divided into the subclasses Chondrostei and Neopterygii. The Neopterygii, in turn, are divided into the infraclasses Holostei and Teleostei, during the Mesozoic and Cenozoic the teleosts in particular diversified widely, and as a result, 96% of all known fish species are teleosts. The cladogram shows the groups of actinopterygians and their relationship to the terrestrial vertebrates that evolved from a related group of fish
19.
Lev Berg
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Lev Semyonovich Berg was a leading Soviet geographer, biologist and ichthyologist who served as President of the Soviet Geographical Society between 1940 and 1950. He also developed his own theory as opposed to the theories of Darwin. Lev Berg was born in Bessarabia, the son of Simon Gregor’evich Berg, a notary and he graduated from the Second Kishinev Gymnasium in 1894. Like some of his relatives, Berg converted to Christianity in order to pursue his studies at Moscow University, at Moscow University, Berg studied hydrobiology and geography. He later studied icthyology and in 1928 was awarded he was also a member of the Russian Academy of Sciences, lev Berg graduated from the Moscow University in 1898. Between 1903 and 1914, he worked in the Museum of Zoology in Saint Petersburg and he was one of the founders of the Geographical Institute, now a Faculty of Geography of the Saint Petersburg University. Berg studied and determined the depth of the lakes of Central Asia, including Balkhash and he developed Dokuchaevs doctrine of natural zones, which became one of the foundations of the Soviet biology. Among his pioneering monographs on climatology were Climate and Life and Foundations of Climatology, during his lifetime, Berg was a towering presence in the science of ichthyology. In 1916, he published four volumes of the study of Fishes of Russia, the fourth edition was issued in 1949 as Freshwater Fishes of the Soviet Union and Adjacent Countries and won him the Stalin Prize. He was said to have discovered the relationship between lampreys and salmon. Bergs name is featured in the Latin appellations of more than 60 species of plants, in 2001, the Central Bank of Transnistria minted a silver coin honoring this native of todays Transnistria, as part of a series of commemorative coins called The Outstanding People of Pridnestrovie. Berg is most well known for his theory called nomogenesis. In the book Berg collected an amount of empirical data which offered a strong criticism of Darwins theory of evolution. Bergs theory of nomogenesis combined arguments from paleontology, zoology and botany to claim that evolution is not a random process, the theory of Nomogenesis emphasized the limitations of natural selection which determine the directionality of evolution. Berg claimed that the variation of characters in species is confined within certain limits due to internal and external factors. Berg distanced himself from both Darwinism and Lamarckism, instead he proposed the concept of directed mass mutations as the main mechanism for directing evolution. This mass transformation is a phenomenon of geological magnitude, according to Berg, newly evolved species beget the subordinate taxonomic categories, and appear to be perfectly adapted to their environments. Although Bergs theory was anti-Darwinian, and anti-Lamarckian, it still advocated adaptive evolution, J B S Haldane called Nomogenesis by far the best anti-Darwinian book of this century
20.
Cutthroat eel
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Cutthroat eels are a family, Synaphobranchidae, of eels, the only members of the suborder Synaphobranchoidei. They are found worldwide in temperate and tropical seas, cutthroat eels range from 23 to 160 cm in length. They are bottom-dwelling fish, found in waters down to about 3,700 m. They are distinguished by the presence of eyes in the larvae. In some classifications, this family is split, with Simenchelys in its own family, the Simenchelyidae
21.
European conger
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The European conger is a species of conger of the family Congridae. It is the largest eel in the world and native to the northeast Atlantic, European congers have an average adult length of 1. Average specimens caught will weigh only 2.5 to 25 kg, females, with an average length at sexual maturity of 2 m, are much larger than males, with an average length at sexual maturity of 1.2 m. The body is long, anguilliform, without scales. The colour is grey, but can also be blackish. A row of white spots is aligned along the lateral line. The head is almost conical, and slightly depressed, the snout is rounded and prominent, with lateral olfactory holes. The large gill openings are in the lateral position, the conical teeth are arranged in rows on the jaws. The dorsal and anal fins are confluent with caudal fin, pectoral fins are present, while ventral fins are absent. Conger eels have similar to moray eels. They usually live amongst rocks in holes, or eel pits and they come out from their holes at night to hunt. These nocturnal predators mainly feed on fish, cephalopods, and crustaceans, although they are thought to scavenge on dead and rotting fish and it is sometimes seen in very shallow water by the shore, but can also go down to 1,170 m. It is usually present on rough, rocky, broken ground, conger eels then stop feeding and leave European waters and make the long migration to the subtropical areas of the Atlantic, such as the Sargasso Sea. Once in this area, they spawn, with the female producing 3 to 8 million eggs, once hatched, the larval conger eels begin to swim back to European waters, where they live until they reach maturity and then begin to migrate to repeat the cycle
22.
Order (biology)
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In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, an immediately higher rank, superorder, may be added directly above order, while suborder would be a lower rank. A taxonomic unit, a taxon, in that rank, in that case the plural is orders. Example, The Juglans and Hickory trees belong to the family Juglandaceae, what does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no agreement, with different taxonomists each taking a different position. There are no rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognised only rarely, for some groups of organisms, consistent suffixes are used to denote that the rank is an order. The Latin suffix -formes meaning having the form of is used for the name of orders of birds and fishes. The suffix -ales is for the name of orders of plants, fungi, for some clades covered by the International Code of Zoological Nomenclature, a number of additional classifications are sometimes used, although not all of these are officially recognised. In their 1997 classification of mammals, McKenna and Bell used two levels between superorder and order, grandorder and mirorder. Michael Novacek inserted them at the same position, michael Benton inserted them between superorder and magnorder instead. This position was adopted by Systema Naturae 2000 and others, in botany, the ranks of subclass and suborder are secondary ranks pre-defined as respectively above and below the rank of order. Any number of further ranks can be used as long as they are clearly defined, the superorder rank is commonly used, with the ending -anae that was initiated by Armen Takhtajans publications from 1966 onwards. Carl Linnaeus was the first to apply it consistently to the division of all three kingdoms of nature in his Systema Naturae, for plants, Linnaeus orders in the Systema Naturae and the Species Plantarum were strictly artificial, introduced to subdivide the artificial classes into more comprehensible smaller groups. In French botanical publications, from Michel Adansons Familles naturelles des plantes and until the end of the 19th century, some of the plant families still retain the names of Linnaean natural orders or even the names of pre-Linnaean natural groups recognised by Linnaeus as orders in his natural classification. Such names are known as family names. In zoology, the Linnaean orders were used more consistently and that is, the orders in the zoology part of the Systema Naturae refer to natural groups. Some of his names are still in use
23.
Family (biology)
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In biological classification, family is one of the eight major taxonomic ranks, it is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks above the rank of genus. In vernacular usage, a family may be named one of its common members, for example, walnuts and hickory trees belong to the family Juglandaceae. What does or does not belong to a family—or whether a family should be recognized at all—are proposed and determined by practicing taxonomists. There are no rules for describing or recognizing a family. Taxonomists often take different positions about descriptions of taxa, and there may be no broad consensus across the community for some time. Some described taxa are accepted broadly and quickly, but others only rarely, if at all, the naming of families is codified by various international codes. In zoological nomenclature, the names of animals end with the suffix -idae. The concept of rank at time was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera. Carolus Linnaeus used the word familia in his Philosophia botanica to denote groups of plants, trees, herbs, ferns, palms. He used this term only in the section of the book. In zoology, the family as an intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes. He used families in some but not in all his orders of insects, families can be used for evolutionary, palaeontological and generic studies because they are more stable than lower taxonomic levels such as genera and species
24.
Genus
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A genus is a taxonomic rank used in the biological classification of living and fossil organisms in biology. In the hierarchy of classification, genus comes above species. In binomial nomenclature, the name forms the first part of the binomial species name for each species within the genus. Felis catus and Felis silvestris are two species within the genus Felis, Felis is a genus within the family Felidae. The composition of a genus is determined by a taxonomist, the standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. Moreover, genera should be composed of units of the same kind as other genera. The term comes from the Latin genus, a noun form cognate with gignere, linnaeus popularized its use in his 1753 Species Plantarum, but the French botanist Joseph Pitton de Tournefort is considered the founder of the modern concept of genera. The scientific name of a genus may be called the name or generic epithet. It plays a role in binomial nomenclature, the system of naming organisms. The rules for the names of organisms are laid down in the Nomenclature Codes. The standard way of scientifically describing species and other lower-ranked taxa is by binomial nomenclature, the generic name forms its first half. For example, the gray wolfs binomial name is Canis lupus, with Canis being the name shared by the wolfs close relatives. The specific name is written in lower-case and may be followed by names in zoology or a variety of infraspecific names in botany. Especially with these names, when the generic name is known from context. Because animals are typically only grouped within subspecies, it is written as a trinomen with a third name. Dog breeds, meanwhile, are not scientifically distinguished, there are several divisions of plant species and therefore their infraspecific names generally include contractions explaining the relation. For example, the genus Hibiscus includes hundreds of other species apart from the Rose of Sharon or common garden hibiscus, Rose of Sharon doesnt have subspecies but has cultivars that carry desired traits, such as the bright white H. syriaca Diana. Hawaiian hibiscus, meanwhile, includes several separate species, since not all botanists agree on the divisions or names between species, it is common to specify the source of the name using author abbreviations
25.
Species
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In biology, a species is the basic unit of biological classification and a taxonomic rank. A species is defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction. While this definition is often adequate, looked at more closely it is problematic, for example, with hybridisation, in a species complex of hundreds of similar microspecies, or in a ring species, the boundaries between closely related species become unclear. Other ways of defining species include similarity of DNA, morphology, all species are given a two-part name, a binomial. The first part of a binomial is the genus to which the species belongs, the second part is called the specific name or the specific epithet. For example, Boa constrictor is one of four species of the Boa genus, Species were seen from the time of Aristotle until the 18th century as fixed kinds that could be arranged in a hierarchy, the great chain of being. In the 19th century, biologists grasped that species could evolve given sufficient time, Charles Darwins 1859 book The Origin of Species explained how species could arise by natural selection. Genes can sometimes be exchanged between species by horizontal transfer, and species may become extinct for a variety of reasons. In his biology, Aristotle used the term γένος to mean a kind, such as a bird or fish, a kind was distinguished by its attributes, for instance, a bird has feathers, a beak, wings, a hard-shelled egg, and warm blood. A form was distinguished by being shared by all its members, Aristotle believed all kinds and forms to be distinct and unchanging. His approach remained influential until the Renaissance, when observers in the Early Modern period began to develop systems of organization for living things, they placed each kind of animal or plant into a context. Many of these early delineation schemes would now be considered whimsical, animals likewise that differ specifically preserve their distinct species permanently, one species never springs from the seed of another nor vice versa. In the 18th century, the Swedish scientist Carl Linnaeus classified organisms according to shared physical characteristics and he established the idea of a taxonomic hierarchy of classification based upon observable characteristics and intended to reflect natural relationships. At the time, however, it was widely believed that there was no organic connection between species, no matter how similar they appeared. However, whether or not it was supposed to be fixed, by the 19th century, naturalists understood that species could change form over time, and that the history of the planet provided enough time for major changes. Jean-Baptiste Lamarck, in his 1809 Zoological Philosophy, described the transmutation of species, proposing that a species could change over time, in 1859, Charles Darwin and Alfred Russel Wallace provided a compelling account of evolution and the formation of new species. Darwin argued that it was populations that evolved, not individuals and this required a new definition of species. Darwin concluded that species are what appear to be, ideas
26.
Predation
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In an ecosystem, predation is a biological interaction where a predator feeds on its prey. Predators may or may not kill their prey prior to feeding on it, but the act of predation often results in the death of the prey, thus predation is often, though not always, carnivory. Other categories of consumption are herbivory, fungivory, and detritivory, all of these are consumer-resource systems. It can often be difficult to separate various types of feeding behaviors. For example, some parasites prey on their host and then lay their eggs on it, for their offspring to feed on it while it continues to live, the key characteristic of predation is the predators direct impact on the prey population. Selective pressures imposed on one another leads to an evolutionary arms race between prey and predator, resulting in various antipredator adaptations. Ways of classifying predation include grouping by trophic level or diet, by specialization, Predators can be classified by their interactions with their prey. Two factors are considered here, how close the predator and prey are, and whether the prey is killed by the predator. A true predator is one that kills and eats another living thing, Predators may hunt actively for prey in pursuit predation, or sit and wait for prey to approach within striking distance, as in ambush predators. Some predation entails venom that subdues a prey before the predator ingests it, as in the box jellyfish, or disables it, in some cases, the venom contributes to the digestion of the prey, as in rattlesnakes and some spiders. In contrast, baleen whales eat millions of microscopic plankton at once, seed and egg predation are true predation, as seeds and eggs are potential organisms. Predators need not eat prey entirely, for example, some predators cannot digest bones, some may eat only part of an organism, but still consistently cause its death. Grazing organisms do not often kill their prey, while some herbivores like zooplankton live on unicellular phytoplankton and therefore, by the individualized nature of the organism, kill their prey, many others only eat a small part of the plant. Grazing livestock may pull some grass out at the roots, but most is simply grazed upon, kelp is frequently grazed in subtidal kelp forests, but regrows at the base of the blade continuously to cope with browsing pressure. Animals may also be grazed upon, female mosquitos land on hosts briefly to gain sufficient proteins for the development of their offspring, starfish may be grazed on, being capable of regenerating lost arms. Parasites can at times be difficult to distinguish from grazers and their feeding behavior is similar in many ways, however they are noted for their close association with their host species. This close living arrangement may be described by the symbiosis, living together. Parasitic organisms range from the mistletoe, a parasitic plant
27.
European eel
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The European eel is a species of eel, a snake-like, catadromous fish. They can reach a length of 1.5 m in exceptional cases, but are normally around 60–80 cm, while captive specimens have lived over 85 years in captivity, the species lifespan in the wild has not been determined. The European eel is a endangered species. Since the 1970s, the numbers of eels reaching Europe is thought to have declined by around 90%, recent work suggests polychlorinated biphenyl pollution may be a factor in the decline. Eels have been important sources of both as adults and as glass eels. Glass-eel fishing using basket traps has been of significant economic value in many river estuaries on the seaboard of Europe. In captivity, European eels can live for long times. According to a report in The Local, a specimen lived 155 years in the well of a home in Brantevik. In 2010, Greenpeace International added the European eel to its red list. In 2010 The Sustainable Eel Group launched the Sustainable Eel Standard, as the European eel population has been falling for some time, a project started by Innovatie Netwerk is researching whether it is possible to breed European eels in captivity. Breeding the European eel is difficult because eels are only able to reproduce after having swum a distance of 6,500 km. In the project, the distance is being simulated by means of a type of swimming machine for the fish. Innovatie Netwerk has also started a project, called InnoFisk Volendam. Much of the European eel’s life history was a mystery for centuries, in the early 1900s, Danish researcher Johannes Schmidt identified the Sargasso Sea as the most likely spawning grounds for European eels. The larvae drift towards Europe in a 300-day migration, when approaching the European coast, the larvae metamorphose into a transparent larval stage called glass eel, enter estuaries, and many start migrating upstream. After entering their continental habitat, the glass eels metamorphose into elvers, as the eel grows, it becomes known as a yellow eel due to the brownish-yellow color of their sides and belly. After 5–20 years in fresh or brackish water, the eels become sexually mature, their eyes grow larger, their flanks become silver, in this stage, the eels are known as silver eels, and they begin their migration back to the Sargasso Sea to spawn. Media related to Anguilla anguilla at Wikimedia Commons Data related to Anguilla anguilla at Wikispecies
28.
Electric eel
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The electric eel is an electric fish, and the only species in its genus. Despite the name, it is not an eel, but rather a knifefish, the electric eel has an elongated, cylindrical body, typically growing to about 2 m in length, and 20 kg in weight, making them the largest species of the Gymnotiformes. Their coloration is dark gray-brown on the back and yellow or orange on the belly, mature males have a darker color on the belly. The mouth is square, and positioned at the end of the snout, the anal fin extends the length of the body to the tip of the tail. As in other fishes, the swim bladder has two chambers. The anterior chamber is connected to the ear by a series of small bones derived from neck vertebrae called the Weberian apparatus. The posterior chamber extends along the length of the body. E. electricus has a sense of hearing. This fish has a respiratory system with gas exchange occurring through epithelial tissue in its buccal cavity. As obligate air-breathers, electric eels must rise to the surface every ten minutes or so to inhale before returning to the bottom, nearly eighty percent of the oxygen used by the fish is obtained in this way. Despite its name, the eel is not closely related to the true eels, but is a member of the neotropical knifefish order. The electric eel has three pairs of organs that produce electricity, the main organ, the Hunters organ. These organs make up four-fifths of its body, and give the electric eel the ability to generate two types of electric discharges, low voltage and high voltage. These organs are made of electrocytes, lined up so a current of ions can flow through them, when the eel finds its prey, the brain sends a signal through the nervous system to the electrocytes. This opens the ion channels, allowing sodium to flow through, by causing a sudden difference in electric potential, it generates an electric current in a manner similar to a battery, in which stacked plates each produce an electric potential difference. In the electric eel, some 5,000 to 6,000 stacked electroplaques can make a shock up to 860 volts and 1 ampere of current for two milliseconds. Such a shock is extremely unlikely to be deadly for an adult human, atrial fibrillation requires that roughly 700 mA be delivered across the heart muscle for 30 ms or more, far longer than the eel can produce. The Sachs organ is associated with electrolocation, inside the organ are many muscle-like cells, called electrocytes
29.
Notacanthidae
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The deep-sea spiny eels are a family, Notacanthidae, of fishes found worldwide below 125 m, and as deep as 3,500 m. The earliest known spiny eel is Pronotacanthus sahelalmae, from the Santonian of what is now Lebanon and their bodies are greatly elongated, though more tapered than in true eels. The caudal fin is small or nonexistent, while the fin is lengthy. They feed on animals attached to or living on the sea floor, such as sea anemones, echinoderms, molluscs, although not true eels, these fish do have a similar leptocephalus larval form. Thus, while adults range from 20 cm to 1.2 m in length, larvae of up to 1.8 m have been recorded
30.
Clade
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A clade is a group of organisms that consists of a common ancestor and all its lineal descendants, and represents a single branch on the tree of life. The common ancestor may be an individual, a population, a species, clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently, over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades, the term clade was coined in 1957 by the biologist Julian Huxley to refer to the result of cladogenesis, a concept Huxley borrowed from Bernhard Rensch. Many commonly named groups are clades, for example, rodents or insects, because in each case, their name refers to a common ancestor with all its descendant branches. Rodents, for example, are a branch of mammals that split off after the end of the period when the clade Dinosauria stopped being the dominant terrestrial vertebrates 66 million years ago, the original population and all its descendants are a clade. The rodent clade corresponds to the order Rodentia, and insects to the class Insecta and these clades include smaller clades, such as chipmunk or ant, each of which consists of even smaller clades. The clade rodent is in included in the mammal, vertebrate. The phenomenon of convergent evolution is, however, responsible for cases where there are misleading similarities in the morphology of groups that evolved from different lineages. The publication of Darwins theory of evolution in 1859 gave this view increasing weight, thomas Henry Huxley, an early advocate of evolutionary theory, proposed a revised taxonomy based on clades. For example, he grouped birds with reptiles, based on fossil evidence, german biologist Emil Hans Willi Hennig is considered to be the founder of cladistics. Taxonomists have increasingly worked to make the taxonomic system reflect evolution, when it comes to naming, however, this principle is not always compatible with the traditional rank-based nomenclature. For these and other reasons, phylogenetic nomenclature has been developed, a clade is by definition monophyletic, meaning that it contains one ancestor and all its descendants. The ancestor can be known or unknown, any and all members of a clade can be extant or extinct, the science that tries to reconstruct phylogenetic trees and thus discover clades is called phylogenetics or cladistics, the latter term coined by Ernst Mayr, derived from clade. The results of analyses are tree-shaped diagrams called cladograms, they. Three methods of defining clades are featured in phylogenetic nomenclature, node-, stem-, the relationship between clades can be described in several ways, A clade located within a clade is said to be nested within that clade. In the diagram, the clade, i. e. the apes. Two clades are sisters if they have a common ancestor
31.
Monognathus
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Monognathus, or onejaw, is the only genus of the family Monognathidae of deep-sea, eel-like fishes. The name comes from the Greek monos meaning one and gnathos meaning jaw, a reference to the mouth in comparison with the rest of the fish. The dorsal and anal fins lack bony supports, the fins are missing. The snout has a fang which is connected to glands, typical lengths are from 4 to 10 cm, the maximum length recorded is 15.9 cm. They are generally black in color, and are found at depths of over 2,000 m, the fifteen known species are, Monognathus ahlstromi Raju,1974 Monognathus berteli J. G. Nielsen & Hartel,1996. Monognathus bertini Bertelsen & J. G. Nielsen,1987, Monognathus boehlkei Bertelsen & J. G. Nielsen,1987. Monognathus herringi Bertelsen & J. G. Nielsen,1987, Monognathus nigeli Bertelsen & J. G. Nielsen,1987. Monognathus ozawai Bertelsen & J. G. Nielsen,1987, Monognathus rajui Bertelsen & J. G. Nielsen,1987. Monognathus rosenblatti Bertelsen & J. G. Nielsen,1987, Monognathus smithi Bertelsen & J. G. Nielsen,1987
32.
Slender giant moray
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The slender giant moray or Gangetic moray, Strophidon sathete, is the longest member of the family of moray eels. Specimens as large as 4 m have been recorded and this species is characterized by an elongated body, as well as brownish-grey dorsal coloration which pales towards the venter. The slender giant moray is found in the Indo-West Pacific Ocean from the Red Sea and it generally lives in the benthic muddy environments of marine and estuarine areas, including inner bays and rivers. Froese, Rainer and Pauly, Daniel, eds
33.
Fish fin
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Fins are usually the most distinctive features of a fish. Apart from the tail or caudal fin, fish fins have no connection with the spine and are supported only by muscles. Their principal function is to help the fish swim, Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, for every type of fin, there are a number of fish species in which this particular fin has been lost during evolution. Bony fishes form a group called Osteichthyes. They have skeletons made of bone, and can be contrasted with cartilaginous fishes which have made of cartilage. Bony fishes are divided into ray-finned and lobe-finned fish, most fish are ray-finned, an extremely diverse and abundant group consisting of over 30,000 species. It is the largest class of vertebrates in existence today, in the distant past, lobe-finned fish were abundant. Nowadays they are extinct, with only eight living species. Bony fish have fin spines and rays called lepidotrichia and they typically have swim bladders, which allows the fish to create a neutral balance between sinking and floating without having to use its fins. However, these are absent in species, and have developed into primitive lungs in the lungfishes. Bony fishes also have an operculum, which helps them breathe without having to use fins to swim, lobe-finned fishes are a class of bony fishes called Sarcopterygii. They have fleshy, lobed, paired fins, which are joined to the body by a single bone, the fins of lobe-finned fish differ from those of all other fish in that each is borne on a fleshy, lobelike, scaly stalk extending from the body. Pectoral and pelvic fins have articulations resembling those of tetrapod limbs and these fins evolved into legs of the first tetrapod land vertebrates, amphibians. They also possess two dorsal fins with separate bases, as opposed to the dorsal fin of ray-finned fish. The coelacanth is another lobe-finned fish which is still extant and it is thought to have evolved into roughly its current form about 408 million years ago, during the early Devonian. Locomotion of the coelacanths is unique to their kind, to move around, coelacanths most commonly take advantage of up or downwellings of the current and drift. They use their fins to stabilize their movement through the water
34.
Dorsal fin
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A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fish, cetaceans, and the ichthyosaurs. Depending on the species, an animal may have one or two of them, wildlife biologists often use the distinctive nicks and wear patterns which develop on the dorsal fins of large cetaceans to identify individuals in the field. The bony or cartilaginous bones that support the base of the fin in fish are called pterygiophores. The main purpose of the fin is to stabilize the animal against rolling. Some species have adapted their dorsal fins to other uses. The sunfish uses the dorsal fin for propulsion, in anglerfish, the anterior of the dorsal fin is modified into a biological equivalent to a fishing pole and a lure known as illicium or esca. Many catfish can lock the leading ray of the fin in an extended position to discourage predation or to wedge themselves into a crevice. Some animals have developed dorsal fins with protective functions, such as spines or venom, for example, both the spiny dogfish and the Port Jackson shark have spines in their dorsal fins which are capable of secreting venom. Like tuna, mackerel and other scombroids, billfish streamline themselves by retracting their fins into a groove in their body when they swim. The shape, size, position and colour of the dorsal fin varies with the type of billfish, for example, the white marlin has a dorsal fin with a curved front edge and is covered with black spots. The huge dorsal fin, or sail, of the sailfish is kept retracted most of the time, sailfish raise them if they want to herd a school of small fish, and also after periods of high activity, presumably to cool down. Fish fin Submarine sail Vertical stabilizer
35.
Ocean
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An ocean is a body of saline water that composes much of a planets hydrosphere. On Earth, an ocean is one of the major divisions of the World Ocean. These are, in descending order by area, the Pacific, Atlantic, Indian, Southern, the word sea is often used interchangeably with ocean in American English but, strictly speaking, a sea is a body of saline water partly or fully enclosed by land. The ocean contains 97% of Earths water, and oceanographers have stated that less than 5% of the World Ocean has been explored, the total volume is approximately 1.35 billion cubic kilometers with an average depth of nearly 3,700 meters. As the world ocean is the component of Earths hydrosphere, it is integral to all known life, forms part of the carbon cycle. The world ocean is the habitat of 230,000 known species, but because much of it is unexplored, the origin of Earths oceans remains unknown, oceans are thought to have formed in the Hadean period and may have been the impetus for the emergence of life. Extraterrestrial oceans may be composed of water or other elements and compounds, the only confirmed large stable bodies of extraterrestrial surface liquids are the lakes of Titan, although there is evidence for the existence of oceans elsewhere in the Solar System. Early in their histories, Mars and Venus are theorized to have had large water oceans. The Mars ocean hypothesis suggests that nearly a third of the surface of Mars was once covered by water, compounds such as salts and ammonia dissolved in water lower its freezing point so that water might exist in large quantities in extraterrestrial environments as brine or convecting ice. Unconfirmed oceans are speculated beneath the surface of many planets and natural satellites, notably. The Solar Systems giant planets are thought to have liquid atmospheric layers of yet to be confirmed compositions. Oceans may also exist on exoplanets and exomoons, including surface oceans of water within a circumstellar habitable zone. Ocean planets are a type of planet with a surface completely covered with liquid. The concept of Ōkeanós has an Indo-European connection, Greek Ōkeanós has been compared to the Vedic epithet ā-śáyāna-, predicated of the dragon Vṛtra-, who captured the cows/rivers. Related to this notion, the Okeanos is represented with a dragon-tail on some early Greek vases, though generally described as several separate oceans, these waters comprise one global, interconnected body of salt water sometimes referred to as the World Ocean or global ocean. This concept of a body of water with relatively free interchange among its parts is of fundamental importance to oceanography. The major oceanic divisions – listed below in descending order of area and volume – are defined in part by the continents, various archipelagos, Oceans are fringed by smaller, adjoining bodies of water such as seas, gulfs, bays, bights, and straits. The Mid-Oceanic Ridge of the World are connected and form the Ocean Ridge, the continuous mountain range is 65,000 km long, and the total length of the oceanic ridge system is 80,000 km long
36.
Anguillidae
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The Anguillidae are a family of ray-finned fish that contains the freshwater eels. The nineteen species and six subspecies in this family are all in the genus Anguilla and they are elongated fish with snake-like bodies, their long dorsal, caudal and anal fins forming a continuous fringe. They are catadromous fish, spending their lives in fresh water. Eels are an important food fish and some species are now farm-raised, many populations in the wild are now threatened and Seafood Watch recommend consumers avoid eating anguillid eels. Members of this family are catadromous, meaning they spend their lives in rivers, lakes, or estuaries. The young eel larvae, called leptocephali, live only in the ocean and they grow larger in size, and in their next growth stage, they are called glass eels. At this stage, they enter estuaries, and when they become pigmented, elvers travel upstream in freshwater rivers, where they grow to adulthood. The spawning areas of some other eels, such as the Japanese eel. Freshwater eels are elongated with tubelike, snake-shaped bodies and they have large, pointed heads and their dorsal fins are usually continuous with their caudal and anal fins, to form a fringe lining the posterior end of their bodies. They have small pectoral fins to help them navigate along river bottoms and their scales are thin and soft. Freshwater eels go through changes in their bodies when going to. Anguillid eels are important food fish, eel aquaculture is a fast-growing industry. Important food eel species include longfin eel, Australian long-finned eel, short-finned eel, most eel production historically has been in Japan, Korea, and Taiwan, but in recent years, the greatest production has been in China. Seafood Watch, one of the most well-known sustainable seafood advisory lists, several species used as unagi have seen their population sizes greatly reduced in the past half century. Catches of the European eel, for example, have declined about 80% since the 1960s, although about 90% of freshwater eels consumed in the US are farm-raised, they are not bred in captivity. Instead, young eels are collected from the wild and then raised in various enclosures, Freshwater eels are carnivores and as such are fed other wild-caught fish, adding another element of unsustainability to current eel-farming practices. Berra, Tim M. Freshwater Fish Distribution
37.
Eel life history
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The eel is a long, thin bony fish of the order Anguilliformes. Because fishermen never caught anything they recognized as young eels, the cycle of the eel was a mystery for a very long period of scientific history. Although more than 6500 publications mention eels, much of their history remains an enigma. The European eel was historically the one most familiar to Western scientists, beginning with Aristotle and he speculated that they were born of earth worms, which he believed were formed of mud, growing from the guts of wet soil rather than through sexual reproduction. Many centuries passed before scientists were able to demonstrate that such spontaneous generation does not occur in nature, other early scientists believed that the eelpout Zoarces viviparus was the mother of eels. In 1777, the Italian Carlo Mondini located an eels gonads, in 1876, as a young student in Austria, Sigmund Freud dissected hundreds of eels in search of the male sex organs. He had to concede failure in his first major published research paper, although the connection between larval eels and adult eels is now well understood, the name leptocephalus is still used for larval eel. The Danish professor Johannes Schmidt, beginning in 1904, led a series of expeditions into the Mediterranean Sea, the expeditions were largely financed by the Carlsberg Foundation. He noted that all the leptocephali he found were very similar and he also observed that the farther out to sea in the Atlantic Ocean he went, the smaller the leptocephali he caught were. In a 1922 expedition, he sailed as far as the Sargasso Sea, south of Bermuda, eels in this so-called recruitment developmental stage are known as glass eels because of the transparency of their bodies. Glass eels typically refers to a stage in the eels complex life history between the leptocephalus stage and the juvenile stage. Glass eels are defined as all developmental stages from completion of leptocephalus metamorphosis until full pigmentation, the term typically refers to a transparent glass eel of the family Anguillidae. One well-known location in which the collection of glass eels takes place is Epney, on the Severn. These freshwater eels spawn in the ocean, and then enter estuaries as glass eels, as the glass eels enter fresh waters, they start to become pigmented and are typically referred to as elvers. The elvers grow larger and are referred to as yellow eels and they can propel themselves over wet grass and dig through wet sand to reach upstream headwaters and ponds, thus colonising the continent. In fresh water, they develop pigmentation, turn into elvers, and feed on such as small crustaceans, worms. After 10 to 14 years, they have matured and grown to a length of 60 to 80 cm, at this stage, they are called yellow eels because of their golden pigmentation. Marine eels of the order Anguilliformes also have a stage, and likely pass through a stage similar to the anguillid glass eels
38.
Larva
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A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a phase of their life cycle. The larvas appearance is very different from the adult form. A larva often has unique structures and organs that do not occur in the adult form and their diet may also be considerably different. Larvae are frequently adapted to separate from adults. For example, some such as tadpoles live almost exclusively in aquatic environments. By living in an environment, larvae may be given shelter from predators. Animals in the stage will consume food to fuel their transition into the adult form. In some species like barnacles, adults are immobile but their larvae are mobile, some larvae are dependent on adults to feed them. In many eusocial Hymenoptera species, the larvae are fed by female workers, in Ropalidia marginata the males are also capable of feeding larvae but they are much less efficient, spending more time and getting less food to the larvae. The larvae of species can become pubescent and do not develop further into the adult form. This is a type of neoteny and it is a misunderstanding that the larval form always reflects the groups evolutionary history. This could be the case, but often the stage has evolved secondarily. In these cases the form may differ more than the adult form from the groups common origin. Within Insects, only Endopterygotes show different types of larvae, several classifications have been suggested by many entomologists, and following classification is based on Antonio Berlese classification in 1913. There are four types of endopterygote larvae types, Apodous larvae - no legs at all and are poorly sclerotized. Based on sclerotization, three forms are recognized. Eucephalous - with well sclerotized head capsule, found in Nematocera, Buprestidae and Cerambycidae families
39.
Leptocephali
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Leptocephalus is the flat and transparent larva of the eel, marine eels, and other members of the superorder Elopomorpha. This is one of the most diverse groups of teleosts, containing 801 species in 24 orders,24 families and this group is thought to have arisen in the Cretaceous period over 140 million years ago. These are all true eels of the order Anguilliformes, the fishes of the other four traditional orders of elopomorph fishes that have this type of larvae are more diverse in their body forms and include the tarpon, bonefish, spiny eel, and pelican eel. Leptocephali all have laterally compressed bodies that contain transparent jelly-like substances on the inside of the body and their body organs are small and they have only a simple tube for a gut. This combination of results in them being very transparent when they are alive. Leptocephali have dorsal and anal fins confluent with caudal fins, and they also lack red blood cells until they begin to metamorphose into the juvenile glass eel stage when they start to look like eels. Leptocephali are also characterized by their teeth that are present until metamorphosis. Leptocephali differ from most fish larvae because they grow to larger sizes and have long larval periods of about three months to more than a year. Another distinguishing feature of these organisms is their mucinous pouch and they move with typical anguilliform swimming motions and can swim forwards and backwards. Their food source was difficult to determine because zooplankton, which are the food of fish larvae, were never seen in their guts. They appear to feed on tiny particles floating free in the ocean, Leptocephali larvae live primarily in the upper 100 metres of the ocean at night, and often a little deeper during the day. Leptocephali are present worldwide in the oceans from southern temperate to tropical latitudes, american eels, European eels, conger eels, and some oceanic species spawn and are found in the Sargasso Sea. Leptocephalus brevirostris was declared as a species in 1856, but was later found to be the larva of Anguilla anguilla. The development of leptocephali can be summarized briefly, the eggs of eels in the Anguilliformes order are quite large compared to those of many other fishes. They are about 1–4 mm in diameter, once the larvae are newly hatched, the yolk extends posteriorly. Some larvae hatch with features of the more developed than others. The preleptocephalus stage is the period immediately after the larvae hatch, during this stage, the larvae do not yet feed externally. These larvae typically have poorly developed eyes and few or no teeth, the leptocephalus stage of the larvae begins after the nutrients from the yolk have been absorbed and the eyes and teeth are formed
40.
Marine snow
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In the deep ocean, marine snow is a continuous shower of mostly organic detritus falling from the upper layers of the water column. It is a significant means of exporting energy from the photic zone to the aphotic zone below. The term was first coined by the explorer William Beebe as he observed it from his bathysphere, as the origin of marine snow lies in activities within the productive photic zone, the prevalence of marine snow changes with seasonal fluctuations in photosynthetic activity and ocean currents. Marine snow can be an important food source for living in the aphotic zone. Marine snow is made up of a variety of organic matter, including dead or dying animals and phytoplankton, protists, fecal matter, sand. A majority of marine snow composition is made up of aggregates of smaller particles held together by a sugary mucus. These are natural polymers exuded as waste products mostly by phytoplankton, mucus secreted by zooplankton also contribute to the constituents of marine snow aggregates. These aggregates grow over time and may reach several centimeters in diameter, Marine snow often forms during algal blooms. As phytoplankton accumulate, they aggregate or get captured in other aggregates, aggregation and sinking is actually thought to be a large component of sources for algae loss from surface water. Most organic components of marine snow are consumed by microbes, zooplankton, the small percentage of material not consumed in shallower waters becomes incorporated into the muddy ooze blanketing the ocean floor, where it is further decomposed through biological activity. Marine snow aggregates exhibit characteristics that fit Goldmans aggregate spinning wheel hypothesis and this hypothesis states that phytoplankton, microorganisms and bacteria live attached to aggregate surfaces and are involved in rapid nutrient recycling. Phytoplankton have been shown to be able to take up nutrients from small local concentrations of organic material, as the aggregates slowly sink to the bottom of the ocean, the many microorganisms residing on them are constantly respiring and contribute greatly to the microbial loop. Aggregates begin as the fraction, which typically contains particles sized between 1 nm and several micrometers. The colloidal fraction of the ocean contains an amount of organic matter unavailable to grazers. This fraction has a higher total mass than either phytoplankton or bacteria but is not readily available due to size characteristics of the particles in relation to potential consumers. The colloidal fraction must aggregate in order to be more bioavailable, Particles in Brownian motion interact randomly due to the impact of solute molecules. These interactions lead to collision and aggregation of small particles. The small aggregates then collide and aggregate with other aggregates and particles until the aggregate in question is several micrometers in diameter, shear Once particles have aggregated to several micrometers in diameter, they begin to accumulate bacteria, since there is sufficient site space for feeding and reproduction
41.
Fish migration
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Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres. Fish usually migrate to feed or to reproduce, but in cases the reasons are unclear. Migrations involves the fish moving from one part of a body to another on a regular basis. Marine forage fish often make large migrations between their spawning, feeding and nursery grounds, movements are associated with ocean currents and with the availability of food in different areas at different times of year. The migratory movements may partly be linked to the fact that the fish cannot identify their own offspring and moving in this way prevents cannibalism, some species have been described by the United Nations Convention on the Law of the Sea as highly migratory species. These are large fish that move in and out of the exclusive economic zones of different nations. Salmon and striped bass are well-known anadromous fish, and freshwater eels are catadromous fish that make large migrations, some fish such as tuna move to the north and south at different times of year following temperature gradients. The patterns of migration are of great interest to the fishing industry, movements of fish in fresh water also occur, often the fish swim upriver to spawn, and these traditional movements are increasingly being disrupted by the building of dams. As with various aspects of fish life, zoologists have developed empirical classifications for fish migrations. Two terms in particular have been in long-standing wide usage, Anadromous fish migrate from the sea up into water to spawn, examples are salmon. Catadromous fish migrate from fresh water down into the sea to spawn, in a 1949 journal article, George S. Myers coined the inclusive term diadromous to refer to all fishes that migrate between the sea and fresh water. Like the two well known terms, it was formed from classical Greek, diadromous proved a useful word, but terms proposed by Myers for other types of diadromous fishes did not catch on. These included amphidromous, potamodromous, and oceanodromous, although these classifications were originated for fishes, they are, in principle, applicable to any aquatic organism. Forage fish often make great migrations between their spawning, feeding and nursery grounds, schools of a particular stock usually travel in a triangle between these grounds. For example, one stock of herrings have their ground in southern Norway, their feeding ground in Iceland. Wide triangular journeys such as these may be important because forage fish, capelin are a forage fish of the smelt family found in the Atlantic and Arctic oceans. In summer, they graze on dense swarms of plankton at the edge of the ice shelf, larger capelin also eat krill and other crustaceans. The capelin move inshore in large schools to spawn and migrate in spring, the migration is affected by ocean currents
42.
Leptocephalus
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Leptocephalus is the flat and transparent larva of the eel, marine eels, and other members of the superorder Elopomorpha. This is one of the most diverse groups of teleosts, containing 801 species in 24 orders,24 families and this group is thought to have arisen in the Cretaceous period over 140 million years ago. These are all true eels of the order Anguilliformes, the fishes of the other four traditional orders of elopomorph fishes that have this type of larvae are more diverse in their body forms and include the tarpon, bonefish, spiny eel, and pelican eel. Leptocephali all have laterally compressed bodies that contain transparent jelly-like substances on the inside of the body and their body organs are small and they have only a simple tube for a gut. This combination of results in them being very transparent when they are alive. Leptocephali have dorsal and anal fins confluent with caudal fins, and they also lack red blood cells until they begin to metamorphose into the juvenile glass eel stage when they start to look like eels. Leptocephali are also characterized by their teeth that are present until metamorphosis. Leptocephali differ from most fish larvae because they grow to larger sizes and have long larval periods of about three months to more than a year. Another distinguishing feature of these organisms is their mucinous pouch and they move with typical anguilliform swimming motions and can swim forwards and backwards. Their food source was difficult to determine because zooplankton, which are the food of fish larvae, were never seen in their guts. They appear to feed on tiny particles floating free in the ocean, Leptocephali larvae live primarily in the upper 100 metres of the ocean at night, and often a little deeper during the day. Leptocephali are present worldwide in the oceans from southern temperate to tropical latitudes, american eels, European eels, conger eels, and some oceanic species spawn and are found in the Sargasso Sea. Leptocephalus brevirostris was declared as a species in 1856, but was later found to be the larva of Anguilla anguilla. The development of leptocephali can be summarized briefly, the eggs of eels in the Anguilliformes order are quite large compared to those of many other fishes. They are about 1–4 mm in diameter, once the larvae are newly hatched, the yolk extends posteriorly. Some larvae hatch with features of the more developed than others. The preleptocephalus stage is the period immediately after the larvae hatch, during this stage, the larvae do not yet feed externally. These larvae typically have poorly developed eyes and few or no teeth, the leptocephalus stage of the larvae begins after the nutrients from the yolk have been absorbed and the eyes and teeth are formed
43.
Gertrude Elizabeth Blood
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Gertrude Elizabeth, Lady Colin Campbell was an Irish-born journalist, author, playwright, and editor. She was married to Lord Colin Campbell, a brother-in-law of Princess Louise and her parents were Irish landowner Edmund Maghlin Blood and Mary Amy Fergusson who had married in 1851. The Blood family had estates in County Clare since the reign of Elizabeth I. Edmund and Mary produced three children, Neptune William, Mary Beatrice and Gertrude Elizabeth, Gertrude, a statuesque dark-eyed and celebrated beauty, met Lord Colin Campbell in October 1880 while visiting friends in Scotland, and they had become engaged within days. The couple married on 21 July 1881, Lord Colin had been born on 9 March 1853, the fifth son of George Douglas Campbell, 8th Duke of Argyll and Lady Elizabeth Georgiana Sutherland-Leveson-Gower. He graduated as a Bachelor of Laws, was the Member of Parliament for Argyllshire from 1878 to 1885, gertrudes mother, though, wanted wedding plans to proceed, perhaps because it would provide an entrée to what she regarded as elevated social circles. The Duke of Argyll opposed the match, feeling that his son would be marrying below his station, the wedding took place in July 1881, the Campbells subsequently taking up residence at 79 Cadogan Place in London. It was later discovered that Lord Colin did indeed have a disease and had infected Gertrude. It is generally assumed that he had syphilis, but there is no conclusive proof as to the nature of the disease, Gertrude was granted a judicial separation from Lord Colin in 1884, on the grounds of cruelty, that he had knowingly infected her. In late 1884 both parties filed for divorce, although the trial did not take place until the end of 1886, William Court Gully, future Speaker of the House of Commons, acted as his counsel. Gertrude was defended by Sir Charles Russell, harry Furniss the illustrator was kept busy during the notorious trial, producing numerous portraits of the personalities involved for the daily newspapers. Proceedings including a visit by the jury to the Campbells London home to verify the butlers testimony about witnessing through a keyhole Lady Colins meetings with other men, with her divorce denied, the couple remained married until Lord Colins death in 1895 of his loathsome disease. The Blood parents had enjoyed a quiet, respectable lifestyle which was thrown into turmoil by the lengthy and that Gertrude Blood had been denied a divorce must be seen in the light of the double standards prevalent in Victorian England. Christabel Pankhurst had the following to say, According to man-made law a wife who is even once unfaithful to her husband has done him an injury which entitles him to divorce her, with the trial over, Blood set about reshaping her life. She had always been fond of writing and turned easily to journalism, writing columns on art and travel, fashion, music and she contributed regularly to the columns of the Saturday Review and the Pall Mall Gazette and later edited the Ladies Field. During her career she used the pseudonyms Véra Tsaritsyn, G. E. Brunefille and she was a confidante of Whistler who described her from his first meeting as the very handsome and exceedingly amiable lady, and George Bernard Shaw saw her as a goddess. Her relationship with Frank Harris and Oscar Wilde, whom she called the white slug, was less cordial. Gertrude knew Duveneck well enough to send some of his Venetian etchings to the New Societys first exhibition in 1881
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Ballysadare
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Ballysadare is a village in County Sligo, Ireland. It is located about 7 kilometres south of Sligo town Centre, the town developed on an important crossing of the Owenmore River. The Ox Mountains are located west of the village, the village itself is named after the falls on the Owenmore River. Ballysadare is in the barony of Leyny, formerly the túath of Lúighne and it is in the diocese of Achonry and parish of Ballysadare. Alternative names for the falls are Ess Mac Modairn and Ess na n-Éan, Ballysadare is a possible location for the town noted as Nagnata on Claudius Ptolemys 2nd century CE co-ordinate map of the world. Ballysadare was anciently a major gathering place for all surrounding districts and this extract is from Colgans Acta Sanctorum Hiberniae. The OHara were the lords of Lúighne, St Féichín was born in the townland of Billa in the parish of Ballysadare. He is said to have studied under St. Nath Í of Achonry further to the south in the same territory, the word Bile means a sacred tree or grove. The townland is the location of the Leaba St. Féichín or St. Feichins bed, the ODuillenain, were erenachs of Ballysadare. The Canons Regular of St. Augustine built a new priory a short distance to the west in Abbeytown Townland in the 13th century. Ballysadare was mentioned in the Annals of the Four Masters 15 times between 1158 and 1602, in 1188,1199,1228,1230,1235,1239,1249,1261,1267,1285,1360,1444,1595 and 1602. In 1360 the Annals of the Four Masters note, A bridge of lime, in 1588 all monastery lands around Ballysadare were seized by the Dublin government on behalf of the Crown. Ballysadare is the site of an ancient silver and lead mine and it is now the site of a quarry. Ballysadare was the location of a Pollexfen Mills, since demolished, there is also a hydro electric power station in the vicinity. The area experienced rapid development during the Celtic Tiger boom, with new housing developments, many of which now lie empty. The village was bypassed by the N4 Sligo-Collooney dual-carriageway, completed in January 1998, the N59 Ballina-Sligo road still winds through the village. It is home to St. Marys College, a school which serves the southern and western environs of County Sligo. List of towns and villages in Ireland
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FishBase
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FishBase is a global species database of fish species. It is the largest and most extensively accessed online database on adult finfish on the web, over time it has evolved into a dynamic and versatile ecological tool that is widely cited in scholarly publications. The site has about 700,000 unique visitors per month, hypotheses, such as this one, could be tested only if large amounts of empirical data were available. At the time, fisheries management used analytical models which required estimates for fish growth and it can be particularly difficult for people in developing countries who need such information. Such a database would be useful if the data has also been standardised and validated. Pauly recruited Rainer Froese, and the beginnings of a software database along these lines was encoded in 1988 and this database, initially confined to tropical fish, became the prototype for FishBase. FishBase was subsequently extended to cover all finfish, and was launched on the Web in August 1996 and it is now the largest and most accessed online database for fish in the world. In 1995 the first CD-ROM was released as FishBase 100, subsequent CDs have been released annually. The software runs on Microsoft Access which operates only on Microsoft Windows, FishBase covers adult finfish, but does not detail the early and juvenile stages of fish. In 1999 a complimentary database, called LarvalBase, went online under the supervision of Bernd Ueberschär. It covers ichthyoplankton and the stage of fishes, with detailed data on fish eggs and larvae, fish identification. Given FishBases success, there was a demand for a database covering forms of life other than finfish. This resulted, in 2006, in the birth of SeaLifeBase, altogether, there are about 300,000 known species in this category. As awareness of FishBase has grown among fish specialists, it has attracted over 1,700 contributors and collaborators, since 2000 FishBase has been supervised by a consortium consisting of nine international institutions. The Leibniz Institute of Marine Sciences in Kiel, Germany, functions as the coordinating body, Catalog of Fishes List of online encyclopedias Bailly N Why there may be discrepancies in the assessment of scientific names between the Catalog of Fishes and FishBase Version 2,6 May 2010. Bailly N, Reyes Jr R, Atanacio R and Froese R Simple Identification Tools in FishBase In, Nimis PL and Vignes Lebbe R. Tools for Identifying Biodiversity, Progress and Problems, pages 31–36. Froese R The science in Fishbase In, Villy Christensen and Jay Maclean Ecosystem Approaches to Fisheries, A Global Perspective, Cambridge University Press, Froese R and Pauly D FishBase 2000, concepts, design and data sources ICLARM, Philippines. Froese R and Pauly D Fishbase as a tool for comparing the life patterns of flatfish Netherlands Journal of Sea Research,32
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Integrated Taxonomic Information System
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The Integrated Taxonomic Information System is an American partnership of federal agencies designed to provide consistent and reliable information on the taxonomy of biological species. The database draws from a community of taxonomic experts. Primary content staff are housed at the Smithsonian National Museum of Natural History, the primary focus of ITIS is North American species, but many groups are worldwide and ITIS continues to collaborate with other international agencies to increase its global coverage. ITIS provides a reference database of scientific and common names for species. As of May 2016, it contains over 839,000 scientific names, synonyms, and common names for terrestrial, marine, data presented in ITIS are considered public information, and may be freely distributed and copied, though appropriate citation is requested. ITIS is frequently used as the de facto source of data in biodiversity informatics projects. It presents the names in a classification that contains author, date, distributional. In addition, common names are available through ITIS in the official languages of the Americas. ITIS and its partner, Species 2000, cooperate to annually produce the Catalogue of Life. The Catalogue of Lifes goal was to complete the global checklist of 1.9 million species by 2011. As of May 2012, the Catalogue of Life has reached 1.4 million species—a major milestone in its quest to complete the first up-to-date comprehensive catalogue of all living organisms, ITIS and the Catalogue of Life are core to the Encyclopedia of Life initiative announced May 2007. EOL will be largely on various Creative Commons licenses. The newer material has been checked to higher standards of taxonomic credibility, biological taxonomy is not fixed, and opinions about the correct status of taxa at all levels, and their correct placement, are constantly revised as a result of new research. Many aspects of classification remain a matter of scientific judgment, the ITIS database is updated to take account of new research as it becomes available, and the information it yields is likely to represent a fair consensus of modern taxonomic opinion. Records within ITIS include information about how far it has been possible to check and its information should be checked against other sources where these are available, and against the primary research scientific literature where possible
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Critically endangered[16]
. PMID 20053660.
"Apodes". New International Encyclopedia. 1905.
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