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100-522: The Cascapedia is known for its Atlantic salmon ( salmo salar ) fishing. With average catches of 20 pounds (9.1 kg) and a record catch of 54 pounds (24 kg), caught in 1886, the river has long been recognized as one of Quebec's richest salmon rivers. Already back in 1835, surveyor Joseph Hamel noted the abundance of fish, including trout, salmon, carp, and whitefish. Several Governors General of Canada, including The Marquess of Lansdowne and Lord Stanley , had summer homes along this river. The river

200-606: A common species with a conservation status of " least concern ", however it has been 25 years since the IUCN has released this status. A more recent regional assessment revealed that the European population of this species is vulnerable, and this might be the same or a similar status globally. Location-specific assessments have shown population declines across parts of the Atlantic Salmon's natural range, with populations along

300-633: A farm among the San Juan Islands in Puget Sound, Washington. Washington went on in 2019 to implement a gradual phase out of salmon farming to be completed by 2025. Despite being the source of considerable controversy, the likelihood of escaped Atlantic salmon establishing an invasive presence in the Pacific Northwest is considered minimal, largely because a number of 20th century efforts aimed at deliberately introducing them to

400-504: A higher conductivity and pH level than typical water of the Canadian Shield . The lack of agriculture and industry keep the river free from pollution. Its water is rated of the highest quality. The Cascapedia basin is also mostly undeveloped with less than 500 hectares (1,200 acres) under cultivation. Logging is more important: 8 percent of the basin area was harvested between 1988 and 1994. The significant tributaries of

500-454: A higher price than some other fish. It has thus long been the target of recreational and commercial fishing , and this, as well as habitat destruction , has impacted the population in some areas. As a result, the species is the subject of conservation efforts in several countries, which appear to have been somewhat successful since the 2000s. Techniques to farm this species using aquacultural methods have also been developed, and at present it

600-781: A kind of trout from its use in the Idylls of the poet Ausonius (4th century CE). Later, the differently coloured smolts were found to be the same species. Other names used for the Atlantic salmon are: bay salmon, black salmon, caplin-scull salmon, fiddler, sebago salmon, silver salmon, outside salmon and winnish. At different points in their maturation and life cycle, they are known as parr, smolt, grilse, grilt, kelt, slink, and spring salmon. Atlantic salmon that do not journey to sea are known as landlocked salmon (or ouananiche  [ fr ] in North America). Atlantic salmon are

700-609: A laboratory setting. Ethologists have been particularly concerned with the evolution of behavior and the understanding of behavior in terms of the theory of natural selection . In one sense, the first modern ethologist was Charles Darwin , whose book, The Expression of the Emotions in Man and Animals , influenced many future ethologists. A subfield of ethology is behavioral ecology which attempts to answer Nikolaas Tinbergen 's four questions with regard to animal behavior: what are

800-684: A mean hybridization rate of 2-3%. This is the highest rate of natural hybridization so far reported and is significantly greater than rates observed elsewhere in Europe. The decline in anadromous salmonid species over the last two to three centuries is correlated with the decline in the North American beaver and European beaver , although some fish and game departments continue to advocate removal of beaver dams as potential barriers to spawning runs. Migration of adult Atlantic salmon may be limited by beaver dams during periods of low stream flows, but

900-413: A new footing, by explaining the processes by which it can occur, and providing observational evidence that it had done so. Darwin's theory was rapidly accepted by the scientific community and soon became a central axiom of the rapidly developing science of biology. The basis for modern genetics began with the work of Gregor Mendel on peas in 1865, although the significance of his work was not realized at

1000-406: A new perspective on the fundamental basis of life. Having previously been the realm of gentlemen naturalists, over the 18th, 19th and 20th centuries, zoology became an increasingly professional scientific discipline . Explorer-naturalists such as Alexander von Humboldt investigated the interaction between organisms and their environment, and the ways this relationship depends on geography, laying

1100-509: A paucity of bone data in archaeological sites relative to other fish species, and the assertion that historical claims of abundance may have been exaggerated. This argument was later challenged in another paper which claimed that lack of archaeological bone fragments could be explained by salmon bones being rare at sites that still have large salmon runs and that salmonid bones in general are poorly recovered relative to other fish species. Atlantic salmon populations were significantly reduced in

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1200-709: A process involving the union of a male and female haploid gamete , each gamete formed by meiosis . Ordinarily, gametes produced by separate individuals unite by a process of fertilization to form a diploid zygote that can then develop into a genetically unique individual progeny. However, some animals are also capable, as an alternative reproductive process, to reproduce parthenogenetically. Parthenogenesis has been described in snakes and lizards (see Misplaced Pages Parthenogenesis in squamates ), in amphibians (see Misplaced Pages Parthenogenesis in amphibians ) and in numerous other species (see Misplaced Pages Parthenogenesis ). Generally, meiosis in parthanogenetically reproducing animals occurs by

1300-403: A slight green or red colouration. The salmon has a fusiform body, and well-developed teeth . All fins, except the adipose fin , are bordered with black. The natural breeding grounds of Atlantic salmon are rivers in Europe and the northeastern coast of North America. In Europe, Atlantic salmon are still found as far south as Spain, and as far north as Russia. Because of sport-fishing, some of

1400-430: A year of good growth, they will move to the sea surface currents that transport them back to their natal river. It is a major misconception that salmon swim thousands of kilometres at sea; instead they surf through sea surface currents. It is possible they find their natal river by smell, although this is not confirmed; only 5% of Atlantic salmon go up the wrong river. The range of an individual Atlantic salmon can thus be

1500-531: Is a 1609 account by Henry Hudson that Atlantic salmon once ran up the Hudson River . In addition, fish scale evidence dating to 10,000 years BP places Atlantic salmon in a coastal New Jersey pond. Two publications from 1988 and 1996 questioned the notion that Atlantic salmon were prehistorically plentiful in New England, when the climate was warmer as it is now. This argument was primarily based on

1600-458: Is a form of scientific taxonomy . Modern biological classification has its root in the work of Carl Linnaeus , who grouped species according to shared physical characteristics. These groupings have since been revised to improve consistency with the Darwinian principle of common descent . Molecular phylogenetics , which uses nucleic acid sequence as data, has driven many recent revisions and

1700-635: Is accessible via Quebec Route 299 that follows the river's course for 69 kilometres (43 mi). Almost its entire course is protected in the Cascapedia River Wildlife Reserve ( réserve faunique de la Rivière-Cascapédia ), established in 1982. Its headwaters and Lake Cascapedia are within the Gaspésie National Park . Its name comes from the Mi'kmaq word gesgapegiag , meaning "strong current" or "large river". It

1800-665: Is administered by the International Code of Zoological Nomenclature . A merging draft, BioCode, was published in 1997 in an attempt to standardize nomenclature, but has yet to be formally adopted. Vertebrate zoology is the biological discipline that consists of the study of vertebrate animals, that is animals with a backbone , such as fish , amphibians , reptiles , birds and mammals . The various taxonomically oriented disciplines i.e. mammalogy , biological anthropology , herpetology , ornithology , and ichthyology seek to identify and classify species and study

1900-480: Is an integrative field of study, uniting concepts and information from evolutionary biology , taxonomy , ecology , physical geography , geology , paleontology and climatology . The origin of this field of study is widely accredited to Alfred Russel Wallace , a British biologist who had some of his work jointly published with Charles Darwin . Molecular biology studies the common genetic and developmental mechanisms of animals and plants, attempting to answer

2000-402: Is being studied. For example, what is learned about the physiology of yeast cells can also apply to human cells. The field of animal physiology extends the tools and methods of human physiology to non-human species. Physiology studies how, for example, the nervous , immune , endocrine , respiratory , and circulatory systems function and interact. Developmental biology is the study of

2100-467: Is commonly sold fresh, canned, or frozen. Wood and stone weirs along streams and ponds were used for millennia to harvest salmon in the rivers of New England. European fishermen gillnetted for Atlantic salmon in rivers using hand-made nets for many centuries and gillnetting was also used in early colonial America. In its natal streams, Atlantic salmon are considered prized recreational fish, pursued by fly anglers during its annual runs. At one time,

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2200-482: Is complete, the parr (young fish) now begin to swim with the current instead of against it. With this behavioral change, the fish are now referred to as smolt. When the smolt reach the sea, they follow sea surface currents and feed on plankton or fry from other fish species such as herring. During their time at sea, they can sense the change in the Earth magnetic field through iron in their lateral line. When they have had

2300-406: Is done on both the microscopic and molecular levels for single-celled organisms such as bacteria as well as the specialized cells in multicellular organisms such as humans . Understanding the structure and function of cells is fundamental to all of the biological sciences. The similarities and differences between cell types are particularly relevant to molecular biology. Anatomy considers

2400-700: Is farmed in great numbers in many places around the world. Although this is now a viable alternative to wild-caught fish, farming methods have attracted criticism from environmentalists. The Atlantic salmon was given its scientific binomial name by Swedish zoologist and taxonomist Carl Linnaeus in 1758 . The name, Salmo salar , derives from the Latin salmo , meaning salmon , and salar , meaning leaper, according to M. Barton, but more likely meaning "resident of salt water" . Lewis and Short's Latin Dictionary (Clarendon Press, Oxford, 1879) translates salar as

2500-534: Is inconclusive. While they may occasionally be aggressive towards each other, the social hierarchy is still unclear. Many have been found to school , especially when leaving the estuary. Adult Atlantic salmon are considered much more aggressive than other salmon, and are more likely to attack other fish than others. Most Atlantic salmon follow an anadromous migration pattern, in that they undergo their greatest feeding and growth in saltwater; however, adults return to spawn in native freshwater streams where

2600-443: Is likely to continue to do so. Biological classification belongs to the science of zoological systematics . Many scientists now consider the five-kingdom system outdated. Modern alternative classification systems generally start with the three-domain system : Archaea (originally Archaebacteria); Bacteria (originally Eubacteria); Eukaryota (including protists , fungi , plants , and animals ) These domains reflect whether

2700-545: Is one of the primary branches of biology . The term is derived from Ancient Greek ζῷον , zōion ('animal'), and λόγος , logos ('knowledge', 'study'). Although humans have always been interested in the natural history of the animals they saw around them, and used this knowledge to domesticate certain species, the formal study of zoology can be said to have originated with Aristotle . He viewed animals as living organisms, studied their structure and development, and considered their adaptations to their surroundings and

2800-415: Is partly based on paleontology , which uses the fossil record to answer questions about the mode and tempo of evolution, and partly on the developments in areas such as population genetics and evolutionary theory. Following the development of DNA fingerprinting techniques in the late 20th century, the application of these techniques in zoology has increased the understanding of animal populations. In

2900-406: Is quantitative, and recently a significant amount of work has been done using computer science techniques such as bioinformatics and computational biology . Molecular genetics , the study of gene structure and function, has been among the most prominent sub-fields of molecular biology since the early 2000s. Other branches of biology are informed by molecular biology, by either directly studying

3000-703: Is reflected in zoology by the presence of animals in Egyptian hieroglyphics. Although the concept of zoology as a single coherent field arose much later, the zoological sciences emerged from natural history reaching back to the biological works of Aristotle and Galen in the ancient Greco-Roman world . In the fourth century BC, Aristotle looked at animals as living organisms, studying their structure, development and vital phenomena. He divided them into two groups: animals with blood, equivalent to our concept of vertebrates , and animals without blood, invertebrates . He spent two years on Lesbos , observing and describing

3100-438: Is still unclear whether they consume them. Once large enough, Atlantic salmon change into the grilse phase, when they become ready to return to the same freshwater tributary they departed from as smolts. After returning to their natal streams, the salmon will cease eating altogether prior to spawning. Although largely unknown, odor – the exact chemical signature of that stream – may play an important role in how salmon return to

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3200-412: Is the alevin stage, when the fish stay in the breeding ground and use the remaining nutrients in their yolk sacs . During this developmental stage, their young gills develop and they become active hunters. Next is the fry stage, where the fish grow and subsequently leave the breeding ground in search of food. During this time, they move to areas with higher prey concentration. The final freshwater stage

3300-564: Is the genus, and sapiens the specific epithet, both of them combined make up the species name. When writing the scientific name of an organism, it is proper to capitalize the first letter in the genus and put all of the specific epithet in lowercase. Additionally, the entire term may be italicized or underlined. The dominant classification system is called the Linnaean taxonomy . It includes ranks and binomial nomenclature . The classification, taxonomy , and nomenclature of zoological organisms

3400-614: Is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. Evolutionary research is concerned with the origin and descent of species , as well as their change over time, and includes scientists from many taxonomically oriented disciplines. For example, it generally involves scientists who have special training in particular organisms such as mammalogy , ornithology , herpetology , or entomology , but use those organisms as systems to answer general questions about evolution. Evolutionary biology

3500-480: Is when they develop into parr , in which they prepare for the trek to the Atlantic Ocean. During these times, the Atlantic salmon are very susceptible to predation . Nearly 40% are eaten by trout alone. Other predators include other fish and birds. Egg and juvenile survival is dependent on habitat quality as Atlantic salmon are sensitive to ecological change. When parr develop into smolt , they begin

3600-545: The anatomy of different groups. It is closely related to evolutionary biology and phylogeny (the evolution of species). Physiology studies the mechanical, physical, and biochemical processes of living organisms by attempting to understand how all of the structures function as a whole. The theme of "structure to function" is central to biology. Physiological studies have traditionally been divided into plant physiology and animal physiology , but some principles of physiology are universal, no matter what particular organism

3700-711: The extirpation of early-run fish in many watersheds. The inshore Atlantic salmon fishery became a major export of the New World, with major fishing operations establishing along the shores of major river systems. The southernmost populations were the first to disappear. Young salmon spend one to four years in their natal river. When they are large enough (c. 15 centimetres (5.9 in)), they smoltify , changing camouflage from stream-adapted with large, gray spots to sea-adapted with shiny sides. They also undergo some endocrinological changes to adapt to osmotic differences between fresh water and seawater habitat. When smoltification

3800-554: The proximate causes of the behavior, the developmental history of the organism, the survival value and phylogeny of the behavior? Another area of study is animal cognition , which uses laboratory experiments and carefully controlled field studies to investigate an animal's intelligence and learning. Biogeography studies the spatial distribution of organisms on the Earth , focusing on topics like dispersal and migration , plate tectonics , climate change , and cladistics . It

3900-702: The substrate and in the current. Some have been known to eat salmon eggs. Plankton such as euphausiids are important food for pre-grilse but amphipods and decapods are also consumed. The most commonly eaten foods include caddisflies , blackflies , mayflies , stoneflies , and chironomids , as well as terrestrial insects. As adults, the salmon prefer capelin as their meal of choice. Capelin are elongated silvery fish that grow up to 20–25 centimetres (8–10 in) long. Other fish consumed include herring , alewives , smelts , scomberids , sand lance , and small cod . Fry and parr have been said to be territorial, but evidence showing them to guard territories

4000-399: The taxonomist . Originally it was thought that species were immutable, but with the arrival of Darwin's theory of evolution, the field of cladistics came into being, studying the relationships between the different groups or clades . Systematics is the study of the diversification of living forms, the evolutionary history of a group is known as its phylogeny , and the relationship between

4100-552: The 16th century. During the Renaissance and early modern period, zoological thought was revolutionized in Europe by a renewed interest in empiricism and the discovery of many novel organisms. Prominent in this movement were Andreas Vesalius and William Harvey , who used experimentation and careful observation in physiology , and naturalists such as Carl Linnaeus , Jean-Baptiste Lamarck , and Buffon who began to classify

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4200-470: The 1980s, developmental biology re-entered evolutionary biology from its initial exclusion from the modern synthesis through the study of evolutionary developmental biology . Related fields often considered part of evolutionary biology are phylogenetics , systematics , and taxonomy . Ethology is the scientific and objective study of animal behavior under natural conditions, as opposed to behaviorism , which focuses on behavioral response studies in

4300-659: The 1980s. Consequently, environmental assessments by the US National Marine Fisheries Service (NMFS) , the Washington Department of Fish and Wildlife and the BC Environmental Assessment Office have concluded the potential risk of Atlantic salmon colonization in the Pacific Northwest is low. A study of Næve et al. (2022) estimated the impact of 50 years of genetic selection and tried to predict

4400-659: The Cascapédia River are (in upstream order): Atlantic salmon The Atlantic salmon ( Salmo salar ) is a species of ray-finned fish in the family Salmonidae . It is the third largest of the Salmonidae, behind Siberian taimen and Pacific Chinook salmon , growing up to a meter in length. Atlantic salmon are found in the northern Atlantic Ocean and in rivers that flow into it. Most populations are anadromous , hatching in streams and rivers but moving out to sea as they grow where they mature, after which

4500-669: The North Atlantic Salmon Fund to buy commercial quotas in the Atlantic from commercial fishermen in an effort to preserve wild Salmo salar stocks. Possibly because of improvements in ocean feeding grounds, returns in 2008 were very positive. On the Penobscot River in Maine, returns were about 940 in 2007, and by mid-July 2008, the return was 1,938. Similar stories were reported in rivers from Newfoundland to Quebec . In 2011, more than 3,100 salmon returned to

4600-784: The Northwest Atlantic, showing that 27.1% of fish in 17 out of 18 rivers examined are artificially stocked or hybrids. Farming of Atlantic salmon in open cages at sea has also been linked, at least in part, to a decline in wild stocks attributed to the passing of parasites from farmed to wild individuals. On the west coast of the United States and Canada, aquaculturists are generally under scrutiny to ensure that non-native Atlantic salmon cannot escape from their open-net pens, however occasional incidents of escape have been documented. During one incident in 2017 , for example, up to 300,000 potentially invasive Atlantic salmon escaped

4700-496: The Norwegian salmon aquaculture production between 2016 and 2019 was used as a base case. The simulation of the expected growth until 2050 (generation 24) gave five different scenarios : Historical (H1), Forecast 1 (F1), Forecast 2 (F2), Forecast 3 (F3) and Forecast 4 (F4). Changes in thermal growth coefficient (TGC) per generation were used in the model to simulate the differences in the five scenarios. The genetic data, H1, and

4800-657: The Penobscot, the most since 1986, and nearly 200 ascended the Narraguagus River , up from the low two digits just a decade before. Zoology Zoology ( UK : / z u ˈ ɒ l ə dʒ i / zoo- OL -ə-jee , US : / z oʊ ˈ ɒ l ə dʒ i / zoh- OL -ə-jee ) is the scientific study of animals . Its studies include the structure , embryology , classification , habits , and distribution of all animals, both living and extinct , and how they interact with their ecosystems . Zoology

4900-434: The United States following European settlement. The fur trade, timber harvesting, dams and mills and agriculture degraded freshwater habitats and lowered the carrying capacity of most North American streams. Beaver populations were trapped to near-extinction by 1800, and log drives and clear-cutting further exacerbated stream erosion and habitat loss. As timber and fur gave way to agriculture, freshwater Atlantic salmon habitat

5000-454: The adults seasonally move upstream again to spawn. When the mature fish re-enter rivers to spawn, they change in colour and appearance. Some populations of this fish only migrate to large lakes, and are "landlocked", spending their entire lives in freshwater. Such populations are found throughout the range of the species. Unlike Pacific species of salmon, S. salar is iteroparous , which means it can survive spawning and return to sea to repeat

5100-449: The animals and plants, considering the adaptations of different organisms and the function of their parts. Four hundred years later, Roman physician Galen dissected animals to study their anatomy and the function of the different parts, because the dissection of human cadavers was prohibited at the time. This resulted in some of his conclusions being false, but for many centuries it was considered heretical to challenge any of his views, so

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5200-413: The area where they hatched. Once heavier than about 250 g, the fish no longer become prey for birds and many fish, although seals do prey upon them. Grey and common seals commonly eat Atlantic salmon. Survivability to this stage has been estimated at between 14 and 53%. Atlantic salmon breed in the rivers of Western Europe from northern Portugal north to Norway , Iceland , and Greenland , and

5300-427: The cells have nuclei or not, as well as differences in the chemical composition of the cell exteriors. Further, each kingdom is broken down recursively until each species is separately classified. The order is: Domain ; kingdom ; phylum ; class ; order ; family ; genus ; species . The scientific name of an organism is generated from its genus and species. For example, humans are listed as Homo sapiens . Homo

5400-434: The clades can be shown diagrammatically in a cladogram . Although someone who made a scientific study of animals would historically have described themselves as a zoologist, the term has come to refer to those who deal with individual animals, with others describing themselves more specifically as physiologists, ethologists, evolutionary biologists, ecologists, pharmacologists, endocrinologists or parasitologists. Although

5500-711: The coast of Maine and the Inner Bay of Fundy now listed as " endangered " under the Endangered Species Act, and the Canadian Species at Risk Act, respectively. Human activities have impacted salmon populations across parts of its range. The major threats are from overfishing and habitat change. Salmon decline in Lake Ontario goes back to the 18th–19th centuries, due to logging and soil erosion, as well as dam and mill construction. By 1896,

5600-517: The determination of the double helical structure of the DNA molecule by Francis Crick and James Watson in 1953, the realm of molecular biology opened up, leading to advances in cell biology , developmental biology and molecular genetics . The study of systematics was transformed as DNA sequencing elucidated the degrees of affinity between different organisms. Zoology is the branch of science dealing with animals . A species can be defined as

5700-647: The discovery of the structure of DNA by Francis Crick and James Watson in 1953, the realm of molecular biology opened up, leading to advances in cell biology , developmental biology and molecular genetics . The history of zoology traces the study of the animal kingdom from ancient to modern times. Prehistoric people needed to study the animals and plants in their environment to exploit them and survive. Cave paintings, engravings and sculptures in France dating back 15,000 years show bison, horses, and deer in carefully rendered detail. Similar images from other parts of

5800-456: The diversity of life and the fossil record , as well as studying the development and behavior of organisms. Antonie van Leeuwenhoek did pioneering work in microscopy and revealed the previously unknown world of microorganisms , laying the groundwork for cell theory . van Leeuwenhoek's observations were endorsed by Robert Hooke ; all living organisms were composed of one or more cells and could not generate spontaneously. Cell theory provided

5900-465: The east coast of North America from Connecticut in the United States north to northern Labrador and Arctic Canada. The species constructs a nest or "redd" in the gravel bed of a stream. The female creates a powerful downdraught of water with her tail near the gravel to excavate a depression. After she and a male fish have eggs and milt (sperm), respectively, upstream of the depression, the female again uses her tail, this time to shift gravel to cover

6000-512: The effect in the industry when the full genetic potential is utilized. This assumes a further development of advanced techniques in the years to come. The authors of the article found that the daily yield of the biomass increased with increasing generations in the historic and forecast scenarios. Further, the production time in seawater to reach the harvest weight of 5100 g is expected to be reduced by 53% in 2050. When production time can be reduced, this will also reduce e.g. time at risk of diseases. In

6100-457: The eggs and milt which have lodged in the depression. Unlike the various Pacific salmon species which die after spawning ( semelparous ), the Atlantic salmon is iteroparous , which means the fish may recondition themselves and return to the sea to repeat the migration and spawning pattern several times, although most spawn only once or twice. Migration and spawning exact an enormous physiological toll on individuals, such that repeat spawners are

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6200-490: The eggs hatch and juveniles grow through several distinct stages. Atlantic salmon do not require saltwater. Numerous examples of fully freshwater (i.e., "landlocked") populations of the species exist throughout the Northern Hemisphere , including a now extinct population in Lake Ontario , which has been shown in recent studies to have spent its entire life cycle in the watershed of the lake. In North America,

6300-836: The exception rather than the norm. Atlantic salmon show high diversity in age of maturity and may mature as parr, one- to five-sea-winter fish, and in rare instances, at older sea ages. This variety of ages can occur in the same population, constituting a ' bet hedging ' strategy against variation in stream flows. So in a drought year, some fish of a given age will not return to spawn, allowing that generation other, wetter years in which to spawn. When in shared breeding habitats, Atlantic salmon will hybridize with brown trout ( Salmo trutta ). Hybrids between Atlantic salmon and brown trout were detected in two of four watersheds studied in northern Spain . The proportions of hybrids in samples of salmon ranged from 0 to 7-7% but these proportions were not significantly homogeneous among locations, resulting in

6400-430: The fish are cleaned and cloth dried. Sperm and eggs are mixed, washed, and placed into freshwater. Adults recover in flowing, clean, well- aerated water. Some researchers have even studied cryopreservation of their eggs. Fry are generally reared in large freshwater tanks for 12 to 20 months. Once the fish have reached the smolt phase, they are taken out to sea, where they are held for up to two years. During this time,

6500-717: The fish grow and mature in large cages off the coasts of Canada, the US, or parts of Europe. There are many different commercially available cage designs built to operate in a wide variety of aquatic conditions. High-density polyethylene (HDPE) cages are widely used, with HDPE pipes forming a floating collar ring onto which the fish net pen is secured and suspended in the water below. Advancements in cage technologies have allowed for reduction in fish escapes, improvement in growing conditions, and maximization of aquaculture production volume per unit area of growing space. Farmed Atlantic salmon are known to occasionally escape from cages and enter

6600-404: The forms of macroscopic structures such as organs and organ systems. It focuses on how organs and organ systems work together in the bodies of humans and other animals, in addition to how they work independently. Anatomy and cell biology are two studies that are closely related, and can be categorized under "structural" studies. Comparative anatomy is the study of similarities and differences in

6700-431: The foundations for biogeography , ecology and ethology . Naturalists began to reject essentialism and consider the importance of extinction and the mutability of species . These developments, as well as the results from embryology and paleontology , were synthesized in the 1859 publication of Charles Darwin 's theory of evolution by natural selection ; in this Darwin placed the theory of organic evolution on

6800-502: The function of their parts. Modern zoology has its origins during the Renaissance and early modern period, with Carl Linnaeus , Antonie van Leeuwenhoek , Robert Hooke , Charles Darwin , Gregor Mendel and many others. The study of animals has largely moved on to deal with form and function, adaptations, relationships between groups, behaviour and ecology. Zoology has increasingly been subdivided into disciplines such as classification , physiology , biochemistry and evolution . With

6900-633: The habitat of wild populations. Interbreeding between escaped farm fish and wild fish decreases genetic diversity and introduces "the potential to genetically alter native populations, reduce local adaptation and negatively affect population viability and character". A study in 2000 demonstrated that the genes of farmed Atlantic salmon intrude wild populations mainly through wild males breeding with farmed females, though farmed specimens showed reduced capacity for breeding success overall compared to their wild counterparts. Further study in 2018 discovered extensive cross-breeding of wild and farmed Atlantic salmon in

7000-429: The impact it could have until 2050. In order to do this, a common garden experiment was used to model and simulate past and future effects for 11 generations of genetic selection of increased growth rate in Atlantic salmon. To model the contribution that breeding has made in the industry from generation 0 (harvested in 1975– 1978) to generation 11 (harvested in 2017 – 2019), and to simulate growth until 2050 (generation 24),

7100-476: The interactions of molecules in their own right such as in cell biology and developmental biology , or indirectly, where molecular techniques are used to infer historical attributes of populations or species , as in fields in evolutionary biology such as population genetics and phylogenetics . There is also a long tradition of studying biomolecules "from the ground up", or molecularly, in biophysics . Animals generally reproduce by sexual reproduction ,

7200-648: The landlocked strains are frequently known as ouananiche . The freshwater phases of Atlantic salmon vary between two and eight years, according to river location. While the young in southern rivers, such as those to the English Channel , are only one year old when they leave, those further north, such as in Scottish rivers, can be over four years old, and in Ungava Bay , northern Quebec, smolts as old as eight years have been encountered. The first phase

7300-404: The largest group of organisms in which any two individuals of the appropriate sex can produce fertile offspring; about 1.5 million species of animal have been described and it has been estimated that as many as 8 million animal species may exist. An early necessity was to identify the organisms and group them according to their characteristics, differences and relationships, and this is the field of

7400-633: The largest species in their genus, Salmo . After two years at sea, the fish average 71 to 76 cm (28 to 30 in) in length and 3.6 to 5.4 kg (7.9 to 11.9 lb) in weight. But specimens that spend four or more winters feeding at sea can be much larger. An Atlantic salmon netted in 1960 in Scotland, in the estuary of the river Hope, weighed 49.44 kg (109.0 lb), the heaviest recorded in all available literature. Another netted in 1925 in Norway measured 160.65 cm (63.25 in) in length,

7500-417: The longest Atlantic salmon on record. The colouration of young Atlantic salmon does not resemble the adult stage. While they live in fresh water, they have blue and red spots. At maturity, they take on a silver-blue sheen. The easiest way of identifying them as an adult is by the black spots predominantly above the lateral line , though the caudal fin is usually unspotted. When they reproduce, males take on

7600-639: The most conservative forecast scenario, F1, simulate what can be expected in 2050 if the trend from generation 0 through 11 is maintained. The following forecast scenarios assume a greater increase in genetic growth with a larger increase in the TGC in the generations to come. In the next two generations, more advanced selection methods such as marker assisted selection (from generation 10) and genomic selection (from generation 11) were implemented. This resulted in increased gain in selection for growth and simulated F2 and F3. The most progressive scenario, F4, aimed at exploring

7700-458: The most progressive scenario, mortality in seawater was expected to be reduced by up to 50%. Further, the authors found that production per license can increase by up to 121%. Additionally, 77% of the new volume needed to achieve five million tonnes in 2050, may be provided by genomic selection. However, one should keep in mind that this article was published by the firm Aquagen, and can possibly be biased and too optimistic. The IUCN rates this as

7800-597: The presence of juvenile salmon upstream of the dams suggests they are penetrated by parr . Downstream migration of Atlantic salmon smolts was similarly unaffected by beaver dams, even in periods of low flows. In a 2003 study, Atlantic salmon and sea-run brown trout spawning in the Numedalslågen River and 51 of its tributaries in southeastern Norway was unhindered by beavers. In a restored, third-order stream in northern Nova Scotia, beaver dams generally posed no barrier to Atlantic salmon migration except in

7900-524: The process again in another year with 5–10% returning to the sea to spawn again. Such individuals can grow to extremely large sizes, although they are rare. The different life stages of the fish are known by many different names in English: alevin , fry , parr and smolt . Atlantic salmon is considered a very healthy food and one of the fish with a more refined taste in many cultures. As such it features in numerous popular traditional cuisines and can fetch

8000-517: The processes by which animals and plants reproduce and grow. The discipline includes the study of embryonic development , cellular differentiation , regeneration , asexual and sexual reproduction , metamorphosis , and the growth and differentiation of stem cells in the adult organism. Development of both animals and plants is further considered in the articles on evolution , population genetics , heredity , genetic variability , Mendelian inheritance , and reproduction . Evolutionary biology

8100-493: The questions regarding the mechanisms of genetic inheritance and the structure of the gene . In 1953, James Watson and Francis Crick described the structure of DNA and the interactions within the molecule, and this publication jump-started research into molecular biology and increased interest in the subject. While researchers practice techniques specific to molecular biology, it is common to combine these with methods from genetics and biochemistry . Much of molecular biology

8200-796: The rates of Atlantic salmon mortality at sea more than doubled in the western Atlantic. Rivers of the coast of Maine , southern New Brunswick and much of mainland Nova Scotia saw runs drop precipitously, and even disappear . An international effort to study the increased mortality rate was organized by the North Atlantic Salmon Conservation Organization . In 2000 the numbers of Atlantic salmon dropped to very low levels in Newfoundland , Canada. In 2007 at least one sport fishing organization from Iceland and Scandinavia blamed less fish caught by recreational anglers on overfishing at sea, and thus created

8300-616: The region were ultimately unsuccessful. From 1905 until 1935, for example, in excess of 8.6 million Atlantic salmon of various life stages (predominantly advanced fry) were intentionally introduced to more than 60 individual British Columbia lakes and streams. Historical records indicate, in a few instances, mature sea-run Atlantic salmon were captured in the Cowichan River ; however, a self-sustaining population never materialized. Similarly unsuccessful results were realized after deliberate attempts at introduction by Washington as late as

8400-494: The results of his own investigations. His general approach was surprisingly modern, and he wrote, "For it is [the task] of natural science not simply to accept what we are told but to inquire into the causes of natural things." An early pioneer was Conrad Gessner , whose monumental 4,500-page encyclopedia of animals, Historia animalium , was published in four volumes between 1551 and 1558. In Europe, Galen's work on anatomy remained largely unsurpassed and unchallenged up until

8500-503: The rise of the germ theory of disease , though the mechanism of inheritance remained a mystery. In the early 20th century, the rediscovery of Mendel's work led to the rapid development of genetics , and by the 1930s the combination of population genetics and natural selection in the modern synthesis created evolutionary biology . Research in cell biology is interconnected to other fields such as genetics, biochemistry , medical microbiology , immunology , and cytochemistry . With

8600-495: The river where they are born and the sea surface currents that are connected to that river in a circular path. Wild salmon continued to disappear from many rivers during the twentieth century due to overfishing and habitat change. Young salmon begin a feeding response within a few days. After the yolk sac is absorbed by the body, they begin to hunt. Juveniles start with tiny invertebrates, but as they mature, they may occasionally eat small fish. During this time, they hunt both in

8700-428: The smallest upstream reaches in years of low flow where pools were not deep enough to enable the fish to leap the dam or without a column of water over-topping the dam for the fish to swim up. The importance of winter habitat to salmonids afforded by beaver ponds may be especially important in streams of northerly latitudes without deep pools where ice cover makes contact with the bottom of shallow streams. In addition,

8800-543: The species supported an important commercial fishery, but having become endangered throughout its range globally, wild-caught Atlantic salmon are now virtually absent from the market. Instead, nearly all are from aquaculture farms, predominantly in Norway, Chile, Canada, the UK, Ireland, Faroe Islands , Russia and Tasmania in Australia. Adult male and female fish are anaesthetised ; their eggs and sperm are "stripped" after

8900-533: The species was declared extirpated from the lake. In the 1950s, salmon from rivers in the United States and Canada, as well as from Europe, were discovered to gather in the sea around Greenland and the Faroe Islands . A commercial fishing industry was established, taking salmon using drift nets . After an initial series of record annual catches, the numbers crashed; between 1979 and 1990, catches fell from four million to 700,000. Beginning around 1990,

9000-432: The species' southern populations in northern Spain are growing smaller. The species distribution is easily influenced by changes in freshwater habitat and climate. Atlantic salmon are a cold-water fish species and are particularly sensitive to changes in water temperature. The Housatonic River , and its Naugatuck River tributary, hosted the southernmost Atlantic salmon spawning runs in the United States. However, there

9100-499: The structures and mechanisms specific to those groups. The rest of the animal kingdom is dealt with by invertebrate zoology , a vast and very diverse group of animals that includes sponges , echinoderms , tunicates , worms , molluscs , arthropods and many other phyla , but single-celled organisms or protists are not usually included. Cell biology studies the structural and physiological properties of cells , including their behavior , interactions, and environment . This

9200-529: The study of anatomy stultified. During the post-classical era , Middle Eastern science and medicine was the most advanced in the world, integrating concepts from Ancient Greece, Rome, Mesopotamia and Persia as well as the ancient Indian tradition of Ayurveda , while making numerous advances and innovations. In the 13th century, Albertus Magnus produced commentaries and paraphrases of all Aristotle's works; his books on topics like botany , zoology, and minerals included information from ancient sources, but also

9300-569: The study of animal life is ancient, its scientific incarnation is relatively modern. This mirrors the transition from natural history to biology at the start of the 19th century. Since Hunter and Cuvier , comparative anatomical study has been associated with morphography , shaping the modern areas of zoological investigation: anatomy , physiology , histology , embryology , teratology and ethology . Modern zoology first arose in German and British universities. In Britain, Thomas Henry Huxley

9400-433: The time. Darwin gave a new direction to morphology and physiology , by uniting them in a common biological theory: the theory of organic evolution. The result was a reconstruction of the classification of animals upon a genealogical basis, fresh investigation of the development of animals, and early attempts to determine their genetic relationships. The end of the 19th century saw the fall of spontaneous generation and

9500-617: The trip to the ocean, which predominantly happens between March and June. Migration allows acclimation to the changing salinity . Once ready, young smolt leave, preferring an ebb tide . Having left their natal streams , they experience a period of rapid growth during the one to four years they live in the ocean. Typically, Atlantic salmon migrate from their home streams to an area on the continental plate off West Greenland . During this time, they face predation from humans, seals , Greenland sharks , skate , cod , and halibut . Some dolphins have been noticed playing with dead salmon, but it

9600-437: The up to eight-year-long residence time of juveniles in freshwater may make beaver-created permanent summer pools a crucial success factor for Atlantic salmon populations. In fact, two-year-old Atlantic salmon parr in beaver ponds in eastern Canada showed faster summer growth in length and mass and were in better condition than parr upstream or downstream from the pond. Atlantic salmon is a popular fish for human consumption and

9700-494: The world illustrated mostly the animals hunted for food and the savage animals. The Neolithic Revolution , which is characterized by the domestication of animals , continued throughout Antiquity. Ancient knowledge of wildlife is illustrated by the realistic depictions of wild and domestic animals in the Near East, Mesopotamia, and Egypt, including husbandry practices and techniques, hunting and fishing. The invention of writing

9800-502: Was a prominent figure. His ideas were centered on the morphology of animals. Many consider him the greatest comparative anatomist of the latter half of the 19th century. Similar to Hunter , his courses were composed of lectures and laboratory practical classes in contrast to the previous format of lectures only. Scientific classification in zoology , is a method by which zoologists group and categorize organisms by biological type , such as genus or species . Biological classification

9900-546: Was first documented on a map by Jean-Baptiste-Louis Franquelin in 1686 as Kichkabeguiak , and appeared as Kaskabijack on a map of 1783. By 1863 Stanislas Drapeau used the current spelling. The Cascapédia River is entirely undammed and wild, and no municipality is using it for its wastewater. Because its source is the Chic Choc Mountains that are largely made up of soluble limestone , its waters are rich in carbonates and low in sulfates and chlorides , with

10000-695: Was further compromised. According to historian D.W. Dunfield (1985) "over half of the historical Atlantic salmon runs had been lost in North America by 1850". As early as 1798, a bill for the preservation of Atlantic Salmon was introduced in Canadian Parliament, to protect populations in Lake Ontario. In the Gulf Region of Nova Scotia it was reported that 31 of the 33 Atlantic salmon streams were blocked off by lumber dams, leading to

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