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Division Eumycota: Meaning, Characteristics and Classification

These are known as constructive waves as they tend to move material up the beach and have little erosive effect. Storm waves arrive on shore in rapid succession and are known as destructive waves , as their swash moves beach material seawards. Under their influence, the sand and shingle on the beach is ground together and abraded.

Around high tide, the power of a storm wave impacting on the foot of a cliff has a shattering effect as air in cracks and crevices is compressed and then expands rapidly with release of pressure.

At the same time, sand and pebbles have an erosive effect as they are thrown against the rocks. Along with other weathering processes such as frost, this tends to undercut the cliff.

Gradually, a wave-cut platform develops at the foot of the cliff and this has a protective effect, reducing further wave-erosion. Material worn from the margins of the land eventually ends up in the sea, where it is subject to attrition as currents flowing parallel to the coast scour out channels and transport material away from its place of origin.

Sediment carried to the sea by rivers settles on the seabed causing deltas to form in estuaries. All these materials move back and forth under the influence of waves, tides, and currents.

Governments make efforts to prevent flooding through building breakwaters , seawalls , and other defenses against the sea. In Britain, the Thames Barrier protects London from storm surges, [75] while the failure of the dykes and levees around New Orleans during Hurricane Katrina created a humanitarian crisis in the United States.

Land reclamation in Hong Kong permitted the construction of Hong Kong International Airport through the leveling and expansion of two smaller islands. Following the adoption of the present UNCLOS , the coastline under international law is a state 's baseline , which is generally but not always equivalent to its low-water line. Over most of geologic time, the sea level has been higher than it is today.

For at least the last years, the sea level has been rising at an average rate of about 1. Additional contributions, as much as one quarter of the total, come from water sources on land, such as melting snow and glaciers and extraction of groundwater for irrigation and other agricultural and human needs.

The sea plays a part in the water cycle , in which water evaporates from the ocean, travels through the atmosphere as vapor , condenses , falls usually as rain or snow again, and then largely returns to the sea. These endorheic basins , particularly in central Asia , sometimes build up permanent salt lakes as inflowing waters evaporate and their dissolved minerals accumulate over time. The largest of these is the Caspian Sea , although it is sometimes counted as a proper sea owing to its basin of now-landlocked oceanic crust.

Oceans contain the greatest quantity of actively-cycled carbon in the world and are second only to the lithosphere in the amount of carbon they store.

The deep layer's concentration of dissolved inorganic carbon is about 15 percent higher than that of the surface layer [86] and it remains there for much longer periods of time. Carbon enters the ocean as atmospheric carbon dioxide dissolves into the surface layers and is converted into carbonic acid , carbonate , and bicarbonate: It can also enter as dissolved organic carbon through rivers and is converted by photosynthetic organisms into organic carbon.

This can either be exchanged throughout the food chain or precipitated into the deeper, more carbon-rich layers as dead soft tissue or in shells and bones as calcium carbonate.

It circulates in this layer for long periods of time before either being deposited as sediment or being returned to surface waters through thermohaline circulation.

Seawater is slightly alkaline and had a preindustrial pH of about 8. One important element for the formation of skeletal material in marine animals is calcium , but calcium carbonate becomes more soluble with pressure, so carbonate shells and skeletons dissolve below its compensation depth. Affected planktonic organisms will include the snail-like molluscs known as pteropods , and single-celled algae called coccolithophorids and foraminifera.

All of these are important parts of the food chain and a diminution in their numbers will have significant consequences. In tropical regions, corals are likely to be severely affected as it becomes more difficult to build their calcium carbonate skeletons, [97] in turn adversely impacting other reef dwellers.

The current rate of ocean chemistry change appears to be without precedent in Earth's geological history, making it unclear how well marine ecosystems will be able to adapt to the shifting conditions of the near future. The oceans are home to a diverse collection of life forms that use it as a habitat.

Since sunlight illuminates only the upper layers, the major part of the ocean exists in permanent darkness.

As the different depth and temperature zones each provide habitat for a unique set of species, the marine environment as a whole encompasses an immense diversity of life. Life may have originated in the sea and all the major groups of animals are represented there. Scientists differ as to precisely where in the sea life arose: Marine habitats can be divided horizontally into coastal and open ocean habitats. Coastal habitats extend from the shoreline to the edge of the continental shelf.

Most marine life is found in coastal habitats, even though the shelf area occupies only 7 percent of the total ocean area. Open ocean habitats are found in the deep ocean beyond the edge of the continental shelf. Alternatively, marine habitats can be divided vertically into pelagic open water , demersal just above the seabed , and benthic sea bottom habitats. A third division is by latitude: Coral reefs, the so-called "rainforests of the sea", occupy less than 0.

Marine primary producers —plants and microscopic organisms in the plankton—are widespread and very diverse. Microscopic photosynthetic algae, phytoplankton, contribute a larger proportion of the world's photosynthetic output than all the terrestrial forests combined. About 45 percent of the sea's primary production of living material is contributed by diatoms. The marine nitrogen cycle consists of complex microbial transformations which include the fixation of nitrogen , its assimilation, nitrification , anammox , and denitrification.

This means that the most productive areas, rich in plankton and therefore also in fish, are mainly coastal. There is a broader spectrum of higher animal taxa in the sea than on land, many marine species have yet to be discovered, and the number known to science is expanding annually. In fact, the oceans teem with life and provide many varying microhabitats. The pelagic zone contains macro - and microfauna and myriad zooplankton which drift with the currents.

Most of the smallest organisms are the larvae of fish and marine invertebrates which liberate eggs in vast numbers because the chance of any one embryo surviving to maturity is so minute.

The demersal zone supports many animals that feed on benthic organisms or seek protection from predators. The seabed provides a range of habitats on or under the surface of the substrate which are used by creatures adapted to these conditions. The tidal zone with its periodic exposure to dehydrating air is home to barnacles , molluscs , and crustaceans.

The neritic zone has many organisms that need light to flourish. Here, sponges , echinoderms , polychaete worms , sea anemones , and other invertebrates live among algal-encrusted rocks. Corals often contain photosynthetic symbionts and live in shallow waters where light penetrates. The extensive calcareous skeletons they extrude build up into coral reefs which are an important feature of the seabed.

These provide a diverse habitat for reef dwelling organisms. There is less sea life on the floor of deeper seas but marine life also flourishes around seamounts that rise from the depths, where fish and other animals congregate to spawn and feed. Close to the seabed live demersal fish that largely feed on pelagic organisms or benthic invertebrates. Some like the detritivores rely on organic material falling to the ocean floor. Others cluster round deep-sea hydrothermal vents where mineral-rich flows of water emerge, supporting communities whose primary producers are sulphide-oxidizing chemoautotrophic bacteria and whose consumers include specialized bivalves, sea anemones, barnacles, crabs, worms, and fish.

Such places support unique biomes where many new microbes and other lifeforms have been discovered. Humans have travelled the sea since prehistoric times , originally on rafts and in dugout , reed , and bark canoes. Most of the early human migrations occurred over land: The hunter-gatherer Ortoiroid people began spreading through the Caribbean from Venezuela 's Orinoco valley by at least the 6th millennium BC. Around the same time, Mesopotamians were using bitumen to caulk their reed boats and, a little later, masted sails.

Herodotus records Egyptian claims that he also commissioned a 3-year-long expedition which circumnavigated Africa from the Red Sea to the Nile delta.

A modified form was used by Columbus for his voyages. The first evidence of its use in Chinese maritime navigation, however, dates to Zhu Yu 's c. Alexander of Neckham 's De naturis rerum , the first European mention of a magnetized needle, dates to and immediately notes its use among sailors.

Accurately determining longitude the ship's position east or west of some fixed point proved much harder. In the 15th century, West European mariners—beginning with Portugal —started making still longer voyages of exploration , using improvements on translated Islamic star charts and a variation on African fishing boats called the caravel. In , Lopes Gonçalves crossed the equator and disproved the Aristotelian notion that a ring of fire would bar exploration of the southern hemisphere.

Bartolomeu Dias rounded the Cape of Good Hope in ; in , Vasco da Gama reached Malindi , where a local pilot showed him how to follow the monsoon to India. In , relying on incorrect estimates of the circumference of the Earth , the Genovese Christopher Columbus sailed from Cadiz to the Canaries and thence into the open Atlantic in a Spanish attempt to reach the Orient.

Instead, he made landfall on an island in the Caribbean Sea. The resulting Columbian Exchange introduced potatoes , corn , and chili peppers to the Old World while smallpox epidemics devastated the indigenous peoples of the Americas.

This disruption and depopulation permitted rapid Spanish conquests and led to the widespread adoption of African slavery to man lucrative tobacco, sugar, indigo, and cotton plantations. In , Gerardus Mercator devised a map projection conveniently making constant bearings rhumb lines straight. Although accurate charting of the coasts of Russia only began in the 18th century and the archipelago of Severnaya Zemlya was not discovered until , [] Novgorodians had been sailing the White Sea since at least the 13th century.

In the early 15th century, Zheng He 's fleet of treasure ships repeatedly sailed from Ming China with 37, men aboard ships, reaching as far as the African coast. The peoples of East Asia were introduced to the true shape of the other continents from the maps of Matteo Ricci. Meanwhile, the determination of longitude continued to involve approximations and guesswork: Great Britain 's Longitude prize was effectively awarded in to the self-educated John Harrison for his sea watch of James Cook used a copy of this on his second and third voyages, which studied the Pacific [] and inspired studies from Russia , France , the Netherlands, and the United States.

Earlier ideas that no life could exist below fathoms meters or 1, feet were disproved in when a Mediterranean line failed and was pulled up from depths four times lower, completely encrusted with marine life. During the mids, Fridtjof Nansen used a specially-designed ship to drift through the northern pack ice , establishing that the Arctic was an open sea.

From , the International Hydrographic Organization in Monaco has standardized surveying and charting of the sea [] and, from , the Discovery Investigations studied whales and mapped the seas around Antarctica. The Cold War and oil exploration funded further deep sea research: Today, the American Global Positioning System GPS enables accurate navigation worldwide using over thirty satellites and message timing so exact as to involve general relativity.

Water-borne trade has been practiced since at least the dawn of civilization , when Sumeria was connected to Harappan India. In the first centuries BC, steppe nomads' interruption of India's access to Siberian gold caused them to open up maritime routes to Malaysia and Indonesia, [] exposing them first to Hindu and then Muslim traders. With the collapse of the Roman Empire, European trade dwindled but it continued to flourish elsewhere.

Following further conquests , Arabians came to dominate maritime trade in the Indian Ocean , spreading Islam along the East African coast and, eventually, Southeast Asia. From the 16th to the 19th centuries, about 13 million people were shipped across the Atlantic to be sold as slaves in the Americas. Nowadays, large quantities of goods are transported by sea, especially across the Atlantic and around the Pacific Rim.

A major trade route passes through the Pillars of Hercules , across the Mediterranean and the Suez Canal to the Indian Ocean and through the Straits of Malacca ; much trade also passes through the English Channel. Over 60 percent of the world's container traffic is conveyed on the top twenty trade routes.

There are two main kinds of freight, bulk cargo and break bulk or general cargo, most of which is now transported in containers. Commodities in the form of liquids, powder or particles are carried loose in the holds of bulk carriers and include oil, grain, coal, ore, scrap metal, sand and gravel.

Break bulk cargo is usually manufactured goods and is transported in packages, often stacked on pallets. Before the arrival of containerization in the s, these goods were loaded, transported and unloaded piecemeal.

Its objectives include developing and maintaining a regulatory framework for shipping, maritime safety, environmental concerns, legal matters, technical co-operation and maritime security. Spearfishing with barbed harpoons along the sea coast was widespread by the Palaeolithic. Improvements in sonar during the world wars were adapted as fishfinders and, during the s, great factory ships caught and processed as many fish in an hour as earlier trawlers had in a season.

As of , there were an estimated At present, the species most frequently landed are herring , cod , anchovy , tuna , flounder , mullet , squid, and salmon. A number of these, as well as large predatory fish, [] remain well below historical levels. Over 3 million vessels are employed in sea fishing. The equipment used to capture the fish may be purse seines , other seine , trawls , dredges, gillnets , and long-lines. The Food and Agriculture Organization of the United Nations is encouraging the development of local fisheries to provide food security to coastal communities and help alleviate poverty.

As well as the wild stock, about 79 million metric tons 87 million tons of food and non-food products were produced by sea farming in , an all-time high. About six hundred species of plants and animals were cultured, some for use in seeding wild populations. The animals raised included finfish , aquatic reptiles , crustaceans, molluscs, sea cucumbers , sea urchins , sea squirts, and jellyfish. Various methods are employed. Mesh enclosures for finfish can be suspended in the open seas, cages can be used in more sheltered waters, or ponds can be refreshed with water at each high tide.

Shrimps can be reared in shallow ponds connected to the open sea. Oysters can be reared on trays or in mesh tubes. Sea cucumbers can be ranched on the seabed. In the s, disease wiped out China's farmed Farrer's scallop and white shrimp and required their replacement by other species. Admiralty law is the particular body of national laws applied to maritime questions and offenses, as the uncertainty of sea voyages has caused the sea to be viewed as a unique jurisdiction since antiquity.

Rhodian , Roman , Byzantine , Trani , and Amalfian laws were important influences on the French , Genovese , and Hanseatic codes which established the first English courts of admiralty. Unlike the usual English common law system, the courts of admiralty hewed closer to Continental practice , leaving it open for abuse that contributed to the American Revolution.

The Law of the Sea is the particular body international law applied to maritime questions and offenses. Empires such as Rome and China long claimed universal jurisdiction ; during the Middle Ages , Italian maritime republics such as Venice and Genoa recognized the existence of rival states but claimed the right to close the seas to their traffic. Truman 's unilateral claim of jurisdiction over the oil reserves of America's continental shelf in [] directly led to the end of the regime.

The "internal waters" landward of the baseline are solely under national control. A "contiguous zone" of a further 12 nmi are permitted for hot pursuit of vessels charged with violating customs, taxation, immigration, or pollution laws in the territorial waters.

Ships may cross numerous time zones on a voyage, so nautical time , introduced in the s, is used in international waters. Each such zone is uniformly 15 degrees of longitude wide, the ship's clock going forward one hour per zone when travelling eastwards. Since the development of coordinated fleets of ships capable of landing an invasion force, naval warfare has been an important aspect in the defense or conquest of maritime states.

The BC Battle of Salamis largely determined the course of the Persian Wars [] not because of its inherent damage however considerable but because Themistocles 's deception and superior strategy left the Athenians capable of disrupting sea-borne supplies at will and potentially striking at the pontoon bridges across the Hellespont , cutting off the Persians' line of retreat. Piracy —both illicit in ancient Cilicia and China and state-supported among the Cretans , Vikings , Japanese , English , and Berbers [] —has remained a problem into the present day , given the expense involved in securely protecting every merchant vessel or in policing extensive coastlines.

In the ancient world, in addition to Salamis , major naval engagements included the Battle of Actium , which permitted the establishment of Augustus 's empire. In the modern era, important naval battles include the English victories against the Armada in and at Trafalgar in , [] which broke the threats of invasion by the superior land forces of the Spanish and French empires.

With steam, mass-produced steel plate, and exploding shells, European gunships permitted the New Imperialism of the 19th century, forcing open access to Africa , China , Korea , and Japan for their merchants on favorable terms. Although internal politics hampered Chinese modernization, American naval power produced a major reform in Japan which bore fruit during the Battle of Tsushima when the Japanese were able to decisively defeat Russia.

Meanwhile, the battles of the Mediterranean [] and Pacific [] [] theaters of the war had shown that air power was capable of overcoming the strongest warships. Although the use of small private vessels for personal transport undoubtably extends back into prehistory, large ships capable of braving the open ocean were typically dedicated to trade or fishing for most of human history.

Even military campaigns would often simply hire or commandeer these private fleets to serve as troop transports , as did the traders, pilgrims , and wealthy tourists of antiquity and the Middle Ages. The voyages of exploration and colonization were often provided for by the crown out of naval funds; where they were not, they were usually chartered or else purchased and then used for shipping supplies after the initial settlement. Dedicated and scheduled local passenger services came to be offered in the 16th and 17th centuries, but the Black Ball was the first trans-Atlantic passenger line.

In the Age of Sail , the duration of such passages depended much on the prevailing winds and the weather.

The 18th-century coastal Margate hoys began the popularization of leisure travel in Britain and Ireland [] that later gathered steam with Thomas Cook 's package tours in the next century. By , the Atlantic crossing took about five days and the passenger lines competed to win the Blue Riband , an unofficial accolade accorded to the fastest liner in regular service.

For twenty years from , the prize went to the RMS Mauretania for its average speed of The sea still remains a venue for recreational boating and large cruise ships. It is also a route for refugees and economic migrants , some traveling in small unseaworthy craft and others smuggled into shipping vessels.

Some flee persecution while many are economic migrants attempting to reach countries where they believe their prospects are brighter. Use of the sea for leisure developed in the nineteenth century and became a significant industry in the twentieth century. Many humans enjoy venturing into the sea: This was not always the case, with sea bathing becoming the vogue in Europe in the 18th century after Dr.

William Buchan advocated the practice for health reasons. Other water sports include kite surfing , where a power kite propels a manned board across the water; [] windsurfing , where the power is provided by a fixed, maneuverable sail; [] and water skiing , where a powerboat is used to pull a skier.

Beneath the surface, freediving is necessarily restricted to shallow descents. Other useful equipment includes fins and snorkels. Scuba equipment allows underwater breathing, permitting hours of time beneath the surface. Deeper dives can be made with specialized equipment and training. The sea offers a very large supply of energy carried by ocean waves , tides , salinity differences, and ocean temperature differences which can be harnessed to generate electricity.

Tidal power uses generators to produce electricity from tidal flows, sometimes by using a dam to store and then release seawater. The Rance barrage , 1 kilometer 0. The large and highly variable energy of waves gives them enormous destructive capability, making affordable and reliable wave machines problematic to develop.

It was soon damaged by waves, then destroyed by a storm. Offshore wind power is captured by wind turbines placed out at sea; it has the advantage that wind speeds are higher than on land, though wind farms are more costly to construct offshore.

Electricity power stations are often located on the coast or beside an estuary so that the sea can be used as a heat sink. A colder heat sink enables more efficient power generation, which is important for expensive nuclear power plants in particular.

There are large deposits of petroleum as oil and natural gas in rocks beneath the seabed. Offshore platforms and drilling rigs extract the oil or gas and store it for transport to land.

Offshore oil and gas production can be difficult due to the remote, harsh environment. Animals may be disorientated by seismic waves used to locate deposits, probably causing the beaching of whales. The infrastructure may cause damage and oil may be spilt. Examples of "Equine Orthopedic" Lectures include " How to Give your Horse an Intramuscular Injection " The site of the IM injection is important for the safety of the horse and the handler.

Choose a large muscle mass that is actively used by the horse Lunging and Ground Driving Video; etc Kellogg Arabian Horse Training Videos" include " Conformation Video - D. Scoggins; Starting with a Colt - D. Scoggins; Endurance Riding - C. Examples of "Horse Videos" Categories which include over "" Videos" " Examples of "Basic Horsemanship" Lessons include " Determining correct nutrient levels; Roughage for horses; Concentrates for horses; Ration number 1: Foal creep ration; Ration number 2: Weaning horse ration; Ration number 3: Yearling, 2-year-old, late pregnancy and lactating mare ration; Daily nutrient needs Mature horses At maintenance; Mares: Last 90 days of gestation; Lactating mare: First two months; Weanling: Form to Function "Horse Conformation: Form to Function" " All bridles have three basic parts: The bit is the primary means of communication.

The reins allow you to manipulate the bit and also serve as a secondary means of communication. The headstall holds the bit in place and may apply pressure to the poll Arabian Horse Judging Video " Jackson; Revised by K. Examples of "Horse Judging Manual" Sections include " Fouts; Compiled by L. Horse Show Rings; etc In this forum we will analyze still shots of horses to demonstrate the factors that allow you to see the gait as diagonal or vertical, the support phase of the gait, the timing of the lift off and set down of the hooves and the tendency to be a ventroflexed or dorsiflexed Knot Tying" Videos include " They're economical can be made quickly and there's a wide range of rope colours and rope types to choose from Start with a foot length of rope There are many aspects that should be considered when fitting a saddle to the horse.

The type, size and build of saddle, along with the conformation of the horse, all play a part in a proper fit Selecting a Saddle to Fit the Rider Sections include " Saddlemaking Videos; Saddlemaking Production Techniques; etc How to saddle a horse; How to unsaddle a horse; How to mount a horse; How to determine saddle seat size; How to determine the correct stirrup length; How to determine western cinch size; etc The Secrets of a Long Saddle Life; etc Horse Locomotion, Dressage, etc.

Examples of "Understanding the Equine Hoof" Videos include " Examples of "Horse Hoofcare" Subject Categories include " Proceedings of the Royal Society A: A 8 November vol. Here, we study the mechanics of the simplest rope trick, the Flat Loop, in which the rope is driven by the steady circular motion of the roper's hand in a horizontal plane.

We first consider the case of a fixed non-sliding honda. Noting that the rope's shape is steady in the reference frame rotating with the hand, we analyse a string model in which line tension is balanced by the centrifugal force and the rope's weight. We use numerical continuation Part I Selecting a Rope: Bodyweight; Meat; Breeding; Wool; etc Condition Scoring of Sheep " Visual Sheep Scores - Version 2 - " Provide the Australian sheep industry with a standardised set of visual assessment scores for the consistent description of important phenotypic traits of all breeds of sheep; Develop a quick and simple scoring system to help sheep classers and breeders select sheep on visually-assessed traits to accelerate genetic gain; etc Enable researchers to estimate the heritability of visually-assessed sheep traits, and to measure their relationships, if any, on important production traits such as fleece weight, fibre diameter, growth rate and body weight Sheep Reference Guides include " Sheep Videos include " Making More from Sheep " Almost leading sheep producers and technical experts helped develop the 11 linked modules in the manual, which cover subjects ranging from soils and pasture to wool and meat marketing, animal health, genetics and farm sustainability The initial investment and annual operation costs of a sheep enterprise are relatively low.

Sheep production requires adequate but not elaborate facilities and equipment Production Records; Ram Selection Ewe Puberty; Reproductive Cycle of the Ewes; etc Bloat; Cheesy gland caseous lymphadenitis in sheep; Eperythrozoonosis in Sheep; External parasites; Foot and mouth disease; Footrot; Internal parasites; Lamb Autopsy; etc Fat scoring sheep and lambs; Feedlotting lambs; How pasture characteristics influence sheep production; Sheep nutrition; etc Examples of "Sheep An Peischel and D.

This concept has been around for decades and has taken many names, including prescribed grazing and managed herbivory. The major difference between good grazing management and targeted grazing is that targeted grazing refocuses outputs of grazing from livestock production to vegetation and landscape enhancement Each "Sheep Diseases" includes " Foot Rot Eradication; etc Scrapie is a fatal, degenerative disease affecting the central nervous system of sheep and goats.

It is among a number of diseases classified as transmissible spongiform encephalopathies TSE. Infected flocks that contain a high percentage of susceptible animals can experience significant production losses Definition; Identification; Diagnosis; Clinical Signs; etc It has been assembled by leading parasitologists, researchers, extension officers, consultants, drench manufacturers and drench resellers Black scour worm; Berber's pole worm; Whipworm; Lungworms; etc Class of Sheep; Sheep Immunity; Nutrition; etc For more information see Sheep Sheep Shearing Demonstration at Vermont Fairs Successfully Slick Shearing Show Lamb " The main reason for slick shearing is to place emphasis on conformation of the lamb.

In addition, many judges prefer lambs to be "slick-shorn", or shorn within three to four days of the show or during the show. Sheep, Mutton, Lamb Grades and Standards include " National Swine Registry includes " The pig embryo is presented in two ways: All of the sections are presented serially in an unlabeled fashion and then select sections have been labeled for you.

The slides start from the crown of the pig embryo and proceed posteriorly towards the rump Dental Anatomy of Pigs " In boars, the canine teeth, or tusks, grow throughout the animal's life. The lower tusks are kept sharp by friction against the upper ones making them formidable weapons. Numerous tubercles make the occlusal surface of Sow Condition Scoring " A scale from 0 emaciated to 5 grossly fat is used in the scoring system which combines both visual appraisal and feel.

Visual appraisal alone is not good enough: Assessing Sow Body Condition " A critical element of successful swine reproduction is managing sows so they do not gain or lose too much weight or body condition between parities.

Maintaining sows in proper body condition throughout their lives can lead to more consistent reproductive performance, but Examples of "Artificial Insemination in Swine: Breeding the Female" Sections include " Swine estrous cycle; Detecting estrus; The female reproductive system; Inseminating the female; etc Click on "Swine Nutrition Guide". Select which ages of pig are affected; Number of pigs affected; Do Pigs have a high temperature, fever? Each "Pig Diseases" includes " Symptoms; Causes; Contributing Factors; Diagnosis Examples of "Bleeding and Intravenous Techniques in Pigs" include " Swine Injection Guide includes " Swine Diseases and Microorganisms; etc Boar or Sow Shelter House; etc Swine Farrowing Building; etc For more information see the Archive: Examples of "Swine" Subject Categories include " Non Infectious Infertility; Pig Reproduction: Swine Production and Management " Examples of "Swine Husbandry" Subject Categories include " Pork Grades and Standards include " Examples of "Porcine Myology" Subject Categories include " Composting Livestock Mortality and Butcher Waste includes " A minute video describes mortality and butcher residual composting featuring eight operations Examples of the "The Rendering Process" Publications include " National Animal Germplasm Program U.

AnGR management tools allow us to evaluate the genetic diversity collected and assess what needs to be added to the collection, compare countries' collections of the same breed and understand how they may be genetically similar or dissimilar, and develop tools that assist with in-situ conservation activities General Overview Drilldown Uses a drilldown format that allows you to see the collection by species, breed, line, and individual.

You can also specify tissue type blood, semen or embryos ; Compare Taxonomies: Allows the user to compare two taxonomies within the repository; Compare Animals: Allows the user to compare two or more animals; Coefficient of Relationship; etc Smithsonian Magazine and Smithsonian. Currently, the USDA facility in Colorado has amassed more than , frozen samples from about 26, animals. The collection, made up of common livestock species as well as fish and shellfish, includes 36 species represented by breeds.

To stock its freezer, the program calls on farmers who own exemplary bulls, boars, rams and roosters to provide samples of animal semen, which must be chilled and overnighted to the facility.

First-time sperm donors are selected after detailed reviews of their pedigree records, to ensure that the animals are not closely related to any which have already contributed to the collection.

In turn, farmers wishing to introduce new genes into their private herds may request semen samples from the facility Australia Rare Breeds " The principal purpose of the Trust is to protect and encourage the conservation and breeding of endangered domestic farm livestock in Australia to ensure their survival worldwide Rare Breeds Canada " Our primary concern is with breeds of heritage significance or those that have had commercial importance in Canada In New Zealand there are true breeds that are rare both here and overseas.

Sudden changes in temperature, even as small as 1. It is therefore essential to have an adequate stock of prepared 12 ppt water for exchange purposes, maintained under the same environmental conditions as the larval tanks, available at all times. Do not suddenly change the larval water with water that has been in a tank standing in bright sunlight!

Dissolved oxygen levels in larval rearing water should be maintained as close as possible to saturation Table 7. You will need to turn the aeration system off for short periods e. Double-check that you have turned the air on again immediately after any tank operation in which you have turned it off.

One of the major causes of larval mortality is operator error on this point. In practice, if the procedures for water changing, tank cleaning and feeding laid down in this manual are adhered to, and there is no failure in the hatchery air distribution system, no problems should be experienced with low oxygen levels. It is not essential to measure dissolved oxygen levels in the larval rearing water, though it would be preferable to do so if a portable meter is available.

This would give you a warning, before the larvae get stressed, that you need to change the water. The amount of organic materials, especially suspended solids, should be minimized to prevent the proliferation of heterogeneous bacteria, reduce biological oxygen demand, and prevent stress to the broodstock and larvae.

Clean the tanks by siphoning excess food and waste as often as needed. Many invisible changes in the chemical water quality of larval-rearing water occur.

These are due mainly to the metabolic wastes produced by the larvae themselves and by live feeds and by the degradation of excess food. Some of these changes can be extremely harmful to larvae. The most serious are increases in the non-ionized 8 form of ammonia NH3 , which is especially evident at high pH and temperature, and in nitrite. It is beyond the scope of this manual to deal with water chemistry but those who wish to study this matter should consult the review by Valenti and Daniels , which also contains references to other publications on this topic.

Recommended procedures to maintain good larval water quality in flow-through systems are given in Box 9. Further recommendations on system hygiene are made later in this manual. Routine care is even more essential in recirculation than in flow-through hatcheries, especially when the filtration system is new. Despite this, those familiar with recirculation systems claim that the amount of labour required is not greater than in flow-through systems.

Following the suggestions of Valenti and Daniels , a routine maintenance schedule for recirculation systems is suggested in Box BOX 9 Recommendations for good larval water quality.

Turn off the air supply to allow solid particles to settle, and siphon off Figures 34a and 34b surplus food particles and metabolic wastes from the bottom of the tank. Do this daily, immediately before one of the feeding operations. Keep the time taken to complete this task to a minimum and turn the air on again as soon as possible.

Make this part of the daily water exchange procedure. Siphoning will also remove any mortalities which have occurred. This provides you with a good opportunity to observe the condition of your larvae.

There is no great danger of losing healthy animals while siphoning because the larvae swim in the body of the water and do not crawl. There may be some live larvae on the bottom of the tank and these may pass through the siphon tube.

Some hatchery operators collect these Figure 35 and return them to the larval tank. You are not recommended to do this. Discard these larvae because they are probably too weak to evade the oncoming siphon tube and are therefore of poor quality. Never hesitate to exchange the larval water in addition to routine water exchange, see below at any time you suspect that the water is poor. They do not appear to be strong enough to swim against the air bubbles, are found only at the edges of the tank, and sometimes jump out of the tank.

Non-feeding larvae can be detected by their colour. Normally they should be brownish, due to the consumption of brine shrimp nauplii. If you are worried about poor water quality, immediately change most of the water, taking care to replace it with water of the correct salinity and temperature.

Regularly exchange some of the water in the tank, according to its quality see above. You should not have to change it during the first three or four days of the larval rearing cycle. Decrease the water level from 70 cm to about 35 cm, partly through the siphoning operation described above, and partly by use of the turn-down drain. Replace the water removed with ready-mixed, aerated, 12 ppt water at the same temperature as that already in the larval tank.

Do this operation before feeding, so that food will not be wasted. Further reading is provided in Valenti and Daniels A simple recirculation system is described in Chowdhury, Bhattacharjee and Angell A wide variety of feeds are employed by different hatcheries, including the nauplii of brine shrimp Artemia spp.

This freshwater prawn manual describes only one feeding regime in detail, which has been found to be effective. However, many alternative feeding systems exist and the readers of this manual may wish to experiment with locally available feeds. Those who wish to consider the use of alternative live foods are recommended to obtain another FAO manual Lavens and Sorgeloos, , which includes sections on the culture and use of rotifers e.

Brachionus plicatilis and cladocerans e. Useful information on live food production is also contained in another FAO publication Moretti, Pedini Fernandez-Criado, Cittolin and Guidastri, , which describes the use of rotifers and Artemia in marine finfish hatcheries.

Two feeds are used in the feeding system described in this manual, namely brine shrimp nauplii Artemia nauplii, referred to subsequently as BSN and prepared egg custard feed hereafter called EC.

BSN are small crustacean nauplii hatched from cysts which can be bought in vacuum packed bags and cans. An example of a feeding schedule is given in Table 8. BOX 10 Maintenance schedule for recirculation systemsin the morning:. Most freshwater prawn larvae do not feed on the first day hatching day. However, you are recommended to provide some BSN in the late afternoon of the first day because some larvae begin to eat early.

From day 2 until day 4, feed BSN five times per day, with the last and main feed in the evening. After that, you can gradually reduce the number of BSN feeds per day until, by day 10, you are only giving BSN at the evening feeding time.

The evening meal should be given as late as possible The amount of BSN you give at each feeding time depends on your visual examination of the larval water. Freshwater prawn larvae do not actively search for food, which is why BSN which swim actively in the same part of the water column as the larvae are such a valuable feed type. The amount of BSN required at any one time depends primarily on the tank volume, not on the number of larvae present, although the latter of course controls the rate at which BSN are consumed.

This concept is clearly illustrated in Box BOX 11 Feeding bsn depends on tank volume, not the number of larvae in it. Normally one larval cycle in this size of tank will consume 1. By day three, you can start feeding tiny quantities of EC, gradually increasing the feeding frequency to five times per day, spread out evenly throughout the day. Give the last feed of EC about Do not give EC for the final late afternoon feeding because the quantity necessary to supply the requirement throughout the night in one feeding would foul the water; use BSN only.

From day 5 you are starting to reduce the frequency of feeding BSN and by day 6 you should be feeding EC about 5 times per day. Continue feeding at this frequency throughout the rest of the larval cycle.

After day 10, you need only give BSN at the evening feeding, to ensure the presence of food during the night. By this time you should be using very much greater quantities of EC at each feeding time. The exact quantity of food to be given at each meal cannot be prescribed because it depends on the utilization of the feed by the larvae.

You must judge this visually. The quantity of EC feed consumed will increase as the larvae grow. The basic rule is that each larva should be seen to be carrying a particle of EC immediately after every EC feeding.

Use EC particles of about 0. The particles of EC must be kept close to the larvae; this is an additional reason for ensuring vigorous aeration in larval tanks. Underfeeding will lead to starvation, cannibalism and slow growth; overfeeding especially if large quantities of EC are obvious before the next feeding time commences will cause water pollution. Should water pollution occur by error, the water must be immediately exchanged, as explained earlier in this manual.

As a very approximate example, you should expect to use about 7. An alternative feeding regime is presented in Table 9. The use of supplemental feed not only tends to reduce feeding costs but is thought to compensate for nutritional deficiencies in Artemia nauplii.

However, the nutritional quality of the Artemia can be increased by enrichment Annex 4. The general recommendations in this section of the manual apply also to recirculation systems but all hatcheries have their own feeding regime variations. For example, some hatcheries that use recirculation systems turn off the water flow system during feeding to avoid BSN leaving the tank. Good hygiene is essential for hatchery success. Ideally, you should not use the same equipment for more than one tank.

Thus each tank would have its own dedicated nets, siphon tubes, spare filters, etc. This is time and money consuming and rarely practised. However, some much more important guidelines must be followed. Water should never be transferred from one larval tank to another. Submersible pumps, which are often used for water transfer in hatcheries, should never be placed in the larval tanks because they are a potential source of disease transfer.

Always drain your larval tanks by gravity or siphon and only use submersible pumps in water storage or mixing tanks. Disinfect all mobile equipment buckets, siphoning tubes, nets, beakers, pipettes, etc.

Dip them in a ppm active chlorine solution 9 , rinsing them very thoroughly with water and storing them dry. Between larval rearing cycles, routinely disinfect the larval tanks. Failure to do this usually results in massive blooms of organisms, such as Zoothamnium, Epistylis, hydroids, etc. Disinfection does not eradicate these organisms but does effectively control their growth. Scrape your tanks between larval cycles, fill them with a ppm active chlorine solution for one day, rinse them very thoroughly with water, dry them in sunlight for one day, and rinse them thoroughly again before use.

Good hygiene and management standards are even more essential in recirculation than in flow-through hatcheries. Mistakes lead to larval mortalities. Before use, immerse all new tanks, filter containers and filter media, and every other piece of hatchery equipment in running freshwater for one or two weeks to eliminate potentially toxic substances.

Then clean and flush the system with filtered freshwater prior to filling it with brackishwater. After filling the system with brackishwater, disinfect it by adding 5 ppm of available chlorine see Box 6 a few days prior to stocking. Run the whole system normally, including the filter, providing aeration; this should remove all the residual chlorine in a few days.

It is possible to do this more quickly by using sodium thiosulphate but this is not recommended, because of the problems noted earlier in this manual. Ozonisation or UV light can be employed to avoid the use of either chlorine or thiosulphate but, of course, these add to the capital costs and have not yet been noted in commercial freshwater prawn hatcheries.

Some additional recommendations for hygiene in recirculation systems are given in Box BOX 12 Additional recommendations for recirculation system hygiene. Most hatchery problems are caused by poor management. The commonest cause of larval loss is not mortalities due to poor water quality or disease, but physical losses due to simple operator error during tank cleaning and siphoning, water exchange, etc. Losses also occur because late-stage larvae close to metamorphosis jump quite a lot and some get stranded above the water line.

Some hatcheries cut out a strip of mosquito screen and stick it to the inside of the tank with epoxy-resin in the region of the water surface level. Since the water level varies it is suggested that the strip of mosquito netting should be about 12 cm wide. This helps to prevent larvae becoming stranded. Macrobrachium hepatopancreatic parvo-like virus MHPV: Black spot sometimes called brown spot or shell disease: Macrobrachium muscle virus MMV: Infections by Fusarium and Saprolegnia: White spot syndrome baculovirus WSBV: Bacterial infection caused by Enterococcus: Obtain and maintain disease-free stock; good management.

Good management, especially maintaining good water quality and avoiding physical damage by handling by transfer, sampling or by other prawns may be caused by over-stocking, poor feeding, etc. Treatment by immersion in 10 ppm oxolinic acid for 1 hour, or 2 ppm nifurpirinol for 96 hours reported.

Treatment by 2 ppm chloramphenicol combined with 2 ppm furazolidone for days reported. Good management, especially by avoiding constructing farms in areas where or operating farms at times when temperature and pH are too high.

Obtain and maintain disease-free stock; good management; treatment of tanks and equipment with lime CaO before stocking. Treatment by application of 10 ppm oxytetracycline combined with 10 ppm furazolidone reported. Good management, especially the avoidance of lower than optimal water temperatures and the accumulation of organic matter and eutrophication; use better water exchange, aeration and circulation and lower feeding rates.

It cannot be over-stressed that while this manual attempts to lay down guidelines for a particular method of freshwater prawn culture, successful hatchery operation is a blend between factory discipline and husbandry.

The most important thing to remember is that if you do not pay close attention to your animals, your hatchery will fail. You and your staff must always closely observe the behaviour of your larvae and the condition of your tanks. BOX 13 Notes on potential disease problems. MANY DISEASE problems are often secondary to, or aided by, a primary failure in tank hygiene, insufficient water exchange, inadequate feed quality, an inappropriate feeding regime, and low dissolved oxygen levels.

All these result in poor larval condition. The most common belong to the genera Epistylis , Zoothamnium and Vorticella. These protozoa move about and attach themselves to the body surface and the gills of the larvae. They are normally cast during the moulting process but can seriously affect larval movement, feeding, and gill operation.

They are also often evident on tank surfaces. Ciliates feed on bacteria and the link with poor tank maintenance is obvious. The medusan stage of small hydrozoans has been reported to actively prey both on brine shrimp nauplii and freshwater prawn larvae.

Problems with hydrozoans are particularly acute when surface water sources are used. The importance of using ground water and, if this is unavailable, proper water treatment is therefore emphasized. Bacterial infections take several forms. The first are chitinolytic bacteria, which erode the surface of the exoskeleton, often following physical damage, and appear as black or brown spots or lesions sometimes referred to as shell disease or can cause loss of appendages.

These moderate to mild occurrences are infrequent and rarely fatal and often disappear when larvae moult. More advanced bacterial involvement of the exoskeleton and underlying tissues may cause high larval mortality from bacterial necrosis. Bacteria, especially of the filamentous type, may also settle on the surfaces of the gills and interfere with respiration.

Internal infections arising after pathogenic bacteria enter via the exterior surfaces or digestive tube may also cause serious disease. Damage is done throughout the body or principally in organs such as the digestive gland. The muscles of larvae subjected to stress or low oxygen levels sometimes become opaque or whitened and often recover if the exterior problem is cured. This syndrome has been associated with excess sunlight but may indicate advanced disease by viral or other pathogens.

Several viruses have been reported to affect freshwater prawns but not all have yet been associated with morbidity or mortality. Most virus problems have occurred during grow-out. However, in the late s heavy mortalities in some Caribbean Macrobrachium hatcheries were attributed to a nodavirus.

The visible symptom was a whitish tail. Fungal infections of larvae may be eliminated by better food hygiene and a reduction in larval density but have caused serious problems in Macrobrachium hatcheries, notably in Taiwan Province of China. The fungal infection experienced in the latter hatcheries could be easily identified by the presence of a mycelial network, which could be observed through the exoskeleton shell of sick or dead larvae.

Several diseases affect freshwater prawn larvae. These are summarized within Table Some preventative measures are listed in Table More information is provided in Johnson and Bueno If you see problems which may be caused by disease you should seek the advice of local aquatic animal health specialists where available and microbiologists for identification and treatment purposes.

Some brief notes are provided in Box Some hatcheries use formalin ppm daily dip for 30 min as an effective remedy for protozoal and hydrozoan infections and fungal diseases.

The flushing process should continue for one hour. Aeration must continue during treatment as normal.

Formalin can also be used at a lower level of ppm for a longer period, followed by a water change after 24 hours. Mortalities from hydroid infestation can also be reduced by transferring healthy larvae to newly disinfected tanks every days. However, you are recommended not to use this substance because it may be toxic to hatchery workers; its use is banned in some countries. Similarly, the use of copper sulphate previously suggested as a 0.

Antibiotics are sometimes used to control filamentous bacteria Leucothrix spp. Some hatcheries use lime CaO as a prophylactic between larval cycles. The use of these and other treatments for disease problems is described in Johnson and Bueno As noted earlier in this section, severe disease problems very frequently begin because of basic management failure.

Such failures will be minimized if you follow the recommendations in this manual. However, diseases will still sometimes occur. You are recommended to totally discard any seriously infected batch, to drain the tanks, and to disinfect all the hatchery equipment. Do not waste time on treating a serious infection. Cut your losses, try to find out the basic cause of the problem, eliminate it, and start a new larval batch.

An important disease in M. As its names indicates, it is most noticeable in the middle of the larval rearing period days when the larvae are at stage VI-VII , when heavy daily mortalities may occur. Mortalities may even start to become obvious as early as day The disease is recognisable by the larvae becoming bluish-grey and swimming slowly in a spiralling pattern, as well as by a reduced rate of consumption of Artemia and poor growth rate. You can reduce the incidence of this disease by cleaning, disinfecting and drying out hatchery equipment between cycles and taking special care in general hygiene throughout the larval cycle.

If there is a severe outbreak of this disease, a full clean-up of the hatchery should be considered. This would mean killing all the larvae and thoroughly disinfecting the whole hatchery installation, so it is not a decision to be taken lightly. The characteristic of this disease is that the larvae get trapped in the old exoskeleton exuvia during moulting.

It is mostly noticed towards the end of the larval rearing cycle, especially at the moult which occurs when stage XI metamorphoses into the PL stage. The mortality rate at this point can be very high. The cause of EED is not known; it may have multiple causes.

It may imply that the diet is nutritionally inadequate and requires enrichment. Difficulties in shedding the old exoskeleton during moulting have also been observed in juvenile and adult prawns.

The moulting process is stressful and may be difficult for weakened animals, and it is at this time that hidden problems become noticeable. Many hatchery operators judge when to make changes in the feeding regime, for example, by the number of days that have elapsed since the larvae were stocked.

This is satisfactory if a larval batch is performing well and you are basing your management on previous experience. You can judge the progress of your larvae more accurately by stereoscopic microscopic examination. You should do this on a daily basis until the first PL appear in the tank.

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