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Mordacia
''Mordacia'' is a genus of lamprey, the sole genus of the family Mordaciidae, also known as the southern topeyed lampreys. The family Mordaciidae is most closely related to the lamprey family Geotriidae, which has a similar Gondwanan distribution, and both families diverged during the Early Cretaceous. Together, their common ancestor diverged from the Petromyzontidae during the Middle Jurassic. They are found in Chile and Australia; the Chilean and one Australian species (''M. lapicida'' and ''M. mordax'') are anadromous fish that spawn in Pacific Ocean, Pacific-draining river basins and mature in the ocean, while the other Australian species (''M. praecox'') spends its whole life in freshwater. Phylogenetic evidence indicates ancient divergences within this genus, with the Chilean and Australian lineages diverging from one another during the Late Cretaceous (100 mya), although both Australian species only diverged from each other during the Pleistocene. Species There are curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mordacia Praecox
''Mordacia praecox'', the Australian brook lamprey or nonparasitic lamprey, is a freshwater species of Mordacia, southern topeyed lamprey that occurs in south-eastern Australia. It has a thin eel-like body around long, with two low dorsal fins on the back half. The skin is dark blue above and grey below. Its eyes are small, and located on the top of its head. Unlike ''Mordacia mordax, M. mordax'', ''M. praecox'' has eyes that appear to have the potential for dichromatic vision despite being similarly adapted for low-light environments. For many years ''M. praecox'' was known only known from the Moruya River, Moruya and Tuross River, Tuross rivers of southern New South Wales. It is believed to have become locally extinct from those rivers sometime between 1995 and 2003, but additional populations have been found in the Wallagaraugh River, which traverses the border between New South Wales and Victoria (state), Victoria, and over 1000 km to the north in the Maroochy River, Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mordacia Mordax
''Mordacia mordax'', known as the short-headed lamprey, Australian lamprey or Murray lamprey, is a species of Mordacia that lives in south-eastern Australia and Tasmania. Mordaciidae is made up of three species: ''M. praedox'', ''M. mordax'', and ''M. lapicida''. ''M. mordax'' is a relatively rare, parasitic vertebrate and, along with the hagfishes, is part of the only surviving group of jawless organisms throughout vertebrate evolution. It has a thin eel-like body up to long, with two low dorsal fins on the back half. The skin is blue-gray or brown. Its eyes are small, and located on the top of its head. Evolution Members of Agnatha have been found in the fossil record for approximately five hundred million years and it has been identified as an important group in tracking vertebrate evolution. Despite being spatially close to the other southern hemisphere family Geotriidae, ''M. mordax'' has been shown to have key proteins with vastly different amino acid compositions. One s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mordacia
''Mordacia'' is a genus of lamprey, the sole genus of the family Mordaciidae, also known as the southern topeyed lampreys. The family Mordaciidae is most closely related to the lamprey family Geotriidae, which has a similar Gondwanan distribution, and both families diverged during the Early Cretaceous. Together, their common ancestor diverged from the Petromyzontidae during the Middle Jurassic. They are found in Chile and Australia; the Chilean and one Australian species (''M. lapicida'' and ''M. mordax'') are anadromous fish that spawn in Pacific Ocean, Pacific-draining river basins and mature in the ocean, while the other Australian species (''M. praecox'') spends its whole life in freshwater. Phylogenetic evidence indicates ancient divergences within this genus, with the Chilean and Australian lineages diverging from one another during the Late Cretaceous (100 mya), although both Australian species only diverged from each other during the Pleistocene. Species There are curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mordacia Lapicida
''Mordacia lapicida'', also known as the Chilean lamprey, is a species of southern topeyed lamprey endemic to southern Chile, where it can be found in riverine and marine habitats. This species is anadromous. This parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ... lamprey can reach a length of SL. Ammocoetes and adults of this species are found in rivers, and occur in fine sand along river banks. The life cycle of a ''Mordacia lapicida'' is divided into three life stages: freshwater rearing, an ocean parasite and an adult spawning stage. Once in the adult stage, individuals migrate into marine waters where they attack and attach themselves to marine fishes. For this species, metamorphosis occurs during August and March. References lapicida Fish of the Pacific O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamprey
Lampreys (sometimes inaccurately called lamprey eels) are a group of Agnatha, jawless fish comprising the order (biology), order Petromyzontiformes , sole order in the Class (biology), class Petromyzontida. The adult lamprey is characterized by a toothed, funnel-like sucking mouth. The common name "lamprey" is probably derived from Latin , which may mean "stone licker" ( "to lick" + "stone"), though the etymology is uncertain. "Lamprey" is sometimes seen for the plural form. About 38 extant species of lampreys are known, with around seven known extinct species. They are classified in three families—two small families in the Southern Hemisphere (Geotriidae, Mordaciidae) and one large family in the Northern Hemisphere (Petromyzontidae). Genetic evidence suggests that lampreys are more closely related to hagfish, the only other living group of jawless fish, than they are to jawed vertebrates, forming the superclass Cyclostomi. The oldest fossils of stem-group lampreys are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the continents of Asia and Australia in the west and the Americas in the east. At in area (as defined with a southern Antarctic border), the Pacific Ocean is the largest division of the World Ocean and the hydrosphere and covers approximately 46% of Earth's water surface and about 32% of the planet's total surface area, larger than its entire land area ().Pacific Ocean . ''Encyclopædia Britannica, Britannica Concise.'' 2008: Encyclopædia Britannica, Inc. The centers of both the Land and water hemispheres, water hemisphere and the Western Hemisphere, as well as the Pole of inaccessi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Of The Pacific Ocean
A fish (: fish or fishes) is an aquatic, anamniotic, gill-bearing vertebrate animal with swimming fins and a hard skull, but lacking limbs with digits. Fish can be grouped into the more basal jawless fish and the more common jawed fish, the latter including all living cartilaginous and bony fish, as well as the extinct placoderms and acanthodians. In a break to the long tradition of grouping all fish into a single class (Pisces), modern phylogenetics views fish as a paraphyletic group. Most fish are cold-blooded, their body temperature varying with the surrounding water, though some large active swimmers like white shark and tuna can hold a higher core temperature. Many fish can communicate acoustically with each other, such as during courtship displays. The study of fish is known as ichthyology. The earliest fish appeared during the Cambrian as small filter feeders; they continued to evolve through the Paleozoic, diversifying into many forms. The earliest fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ian C
Ian or Iain is a name of Scottish Gaelic origin, which is derived from the Hebrew given name (Yohanan, ') and corresponds to the English name John. The spelling Ian is an Anglicization of the Scottish Gaelic forename ''Iain''. This name is a popular name in Scotland, where it originated, as well as in other English-speaking countries. The name has fallen out of the top 100 male baby names in the United Kingdom, having peaked in popularity as one of the top 10 names throughout the 1960s. In 1900, Ian ranked as the 180th most popular male baby name in England and Wales. , the name has been in the top 100 in the United States every year since 1982, peaking at 65 in 2003. Other Gaelic forms of the name "John" include " Seonaidh" ("Johnny" from Lowland Scots), "Seon" (from English), "Seathan", and "Seán" and "Eoin" (from Irish). The Welsh equivalent is Ioan, the Cornish counterpart is Yowan and the Breton equivalent is Yann. Notable people named Ian Given name * Ian Agol (b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Richardson (naturalist)
Sir John Richardson Royal Society of London, FRS FRSE (5 November 1787 – 5 June 1865) was a Scotland, Scottish naval surgeon, natural history, naturalist and Arctic explorer. Life Richardson was born at Nith Place in Dumfries the son of Gabriel Richardson, Provost of Dumfries, and his wife, Anne Mundell. He was educated at Dumfries Grammar School. He was then apprenticed to his maternal uncle, Dr James Mundell, a surgeon in Dumfries. Richardson studied medicine at Edinburgh University, and became a surgeon in the navy in 1807. He traveled with John Franklin in search of the Northwest Passage on the Coppermine Expedition of 1819–1822. Richardson wrote the sections on geology, botany and ichthyology for the official account of the expedition. Franklin and Richardson Mackenzie River expedition, returned to Canada in 1825 and went overland by fur trade routes to the mouth of the Mackenzie River. Franklin was to go as far west as possible and Richardson was to go east to the mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek () 'most' and (; Latinized as ) 'new'. The aridification and cooling trends of the preceding Neogene were continued in the Pleistocene. The climate was strongly variable depending on the glacial cycle, oscillating between cold Glacial period, glacial periods and warmer Interglacial, int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anadromous
Fish migration is mass relocation by fish from one area or body of water to another. 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. Such migrations are usually done for better feeding or to reproduce, but in other cases the reasons are unclear. Fish migrations involve movements of schools of fish on a scale and duration larger than those arising during normal daily activities. Some particular types of migration are ''anadromous'', in which adult fish live in the sea and migrate into fresh water to spawn; and ''catadromous'', in which adult fish live in fresh water and migrate into salt water to spawn. Marine forage fish often make large migrations between their spawning, feeding and nursery grounds. Their movements are associated with ocean currents and with the availability of food in different areas at different times of the year. The migratory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
