|
Salmon Pancreas Disease Virus
Salmon Pancreas disease (PD or SPD) is caused by a species of Salmonid ''Alphavirus'' (SAV) called ''Salmon pancreas disease virus'' (SPDV). The virus was first described in 1976 in Scotland and in 1989 in Norway. It affects farmed Atlantic salmon (''Salmo salar'') caused by Marine SAV2 and SAV3 and has also been identified in Rainbow trout (''Oncorhyncus mykiss'') in the seawater phase caused by SAV2 where the disease is commonly referred to as Sleeping Disease (SD). Salmonid Alphavirus Salmonid Alphavirus is an RNA virus. Six genotypes of SAV have been identified (referred to as SAV1, 2, 3, 4, 5 and 6), differentiated by the nucleic acid sequences of certain genes. The strains of SAV causing PD belong to the genotypes SAV1, Marine SAV2 and SAV3. Diagnosis When the fish is infected, it can cause sudden loss of appetite, lethargy and increased mortality. The general symptoms of this virus infection also include difficulties to maintain a correct position in the water due to mus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alphavirus
''Alphavirus'' is a genus of RNA viruses, the sole genus in the ''Togaviridae'' family. Alphaviruses belong to group IV of the Baltimore classification of viruses, with a positive-sense, single-stranded RNA genome. There are 32 alphaviruses, which infect various vertebrates such as humans, rodents, fish, birds, and larger mammals such as horses, as well as invertebrates. Alphaviruses that could infect both vertebrates and arthropods are referred dual-host alphaviruses, while insect-specific alphaviruses such as Eilat virus and Yada yada virus are restricted to their competent arthropod vector. Transmission between species and individuals occurs mainly via mosquitoes, making the alphaviruses a member of the collection of arboviruses – or arthropod-borne viruses. Alphavirus particles are enveloped, have a 70 nm diameter, tend to be spherical (although slightly pleomorphic), and have a 40 nm isometric nucleocapsid. Genome The alphaviruses are small, spherical, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monovalent Vaccine
A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. The agent stimulates the body's to recognize the agent as a threat, destroy it, and to further recognize and destroy any of the microorganisms associated with that agent that it may encounter in the future. Vaccines can be |
Fish Diseases
Like humans and other animals, fish suffer from diseases and parasites. Fish defences against disease are specific and non-specific. Non-specific defences include skin and scales, as well as the mucus layer secreted by the epidermis that traps microorganisms and inhibits their growth. If pathogens breach these defences, fish can develop inflammatory responses that increase the flow of blood to infected areas and deliver white blood cells that attempt to destroy the pathogens. Specific defences are specialised responses to particular pathogens recognised by the fish's body, that is adaptative immune responses. In recent years, vaccines have become widely used in aquaculture and ornamental fish, for example vaccines for commercial food fishes like Aeromonas salmonicida, furunculosis in salmon and Lactococcosis\Streptococcosis in farmed grey mullet, Tilapia and koi herpes virus in koi. Some commercially important fish diseases are VHS, ICH, and whirling disease. Parasites ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautical Mile
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude. Today the international nautical mile is defined as exactly . The derived unit of speed is the knot, one nautical mile per hour. Unit symbol There is no single internationally agreed symbol, with several symbols in use. * M is used as the abbreviation for the nautical mile by the International Hydrographic Organization. * NM is used by the International Civil Aviation Organization. * nmi is used by the Institute of Electrical and Electronics Engineers and the United States Government Publishing Office. * nm is a non-standard abbreviation used in many maritime applications and texts, including U.S. Government Coast Pilots and Sailing Directions. It conflicts with the SI symbol for nanometre. History The word mile is from the Latin word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biosecurity
Biosecurity refers to measures aimed at preventing the introduction and/or spread of harmful organisms (e.g. viruses, bacteria, etc.) to animals and plants in order to minimize the risk of transmission of infectious disease. In agriculture, these measures are aimed at protecting food crops and livestock from pests, invasive species, and other organisms not conducive to the welfare of the human population. The term includes biological threats to people, including those from pandemic diseases and bioterrorism. The definition has sometimes been broadened to embrace other concepts, and it is used for different purposes in different contexts. The COVID-19 pandemic is a recent example of a threat for which biosecurity measures have been needed in all countries of the world. Background and terminology The term "biosecurity" has been defined differently by various disciplines. The term was first used by the agricultural and environmental communities to describe preventative measur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Farm
upright=1.3, Salmon farming in the sea (mariculture) at Loch Ainort, Isle of Skye">mariculture.html" ;"title="Salmon farming in the sea (mariculture">Salmon farming in the sea (mariculture) at Loch Ainort, Isle of Skye, Scotland Fish farming or pisciculture involves commercial animal husbandry, breeding of fish, usually for food, in fish tanks or artificial pen (enclosure), enclosures such as fish ponds. It is a particular type of aquaculture, which is the controlled cultivation and harvesting of aquatic animals such as fish, crustaceans, molluscs and so on, in natural or pseudo-natural environment. A facility that releases juvenile fish into the wild for recreational fishing or to supplement a species' natural numbers is generally referred to as a fish hatchery. Worldwide, the most important fish species produced in fish farming are carp, catfish, salmon and tilapia. Global demand is increasing for dietary fish protein, which has resulted in widespread overfishing in wild f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Shedding
Viral shedding is the expulsion and release of virus progeny following successful reproduction during a host (biology), host cell (biology), cell infection. Once replication has been completed and the host cell is exhausted of all resources in making viral progeny, the viruses may begin to leave the cell by #Shedding from a cell into extracellular space, several methods. The term is variously used to refer to viral particles shedding from a single cell, from one part of the body into another, and from a body into the environment, where the virus may infect another. Vaccine shedding is a form of viral shedding which can occur in instances of infection caused by some attenuated vaccine, attenuated (or "live virus") vaccines. Means Shedding from a cell into extracellular space Budding (through cell envelope) Budding#Virology, "Budding" through the cell envelope—in effect, borrowing from the cell membrane to create the virus's own viral envelope— into extracellular space is mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multivalent Vaccine
A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. The agent stimulates the body's to recognize the agent as a threat, destroy it, and to further recognize and destroy any of the microorganisms associated with that agent that it may encounter in the future. Vaccines can be prophylactic (to pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fallowing
Crop rotation is the practice of growing a series of different types of crops in the same area across a sequence of growing seasons. It reduces reliance on one set of nutrients, pest and weed pressure, and the probability of developing resistant pests and weeds. Growing the same crop in the same place for many years in a row, known as monocropping, gradually depletes the soil of certain nutrients and selects for a highly competitive pest and weed community. Without balancing nutrient use and diversifying pest and weed communities, the productivity of monocultures is highly dependent on external inputs. Conversely, a well-designed crop rotation can reduce the need for synthetic fertilizers and herbicides by better using ecosystem services from a diverse set of crops. Additionally, crop rotations can improve soil structure and organic matter, which reduces erosion and increases farm system resilience. History Agriculturalists have long recognized that suitable rotations — ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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 the process again in another year. Such individuals can grow to extremely large sizes, althoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Mortality
Fish mortality is a parameter used in fisheries population dynamics to account for the loss of fish in a fish stock through death. The mortality can be divided into two types: * Natural mortality: the removal of fish from the stock due to causes not associated with fishing. Such causes can include disease, competition, cannibalism, old age, predation, pollution or any other natural factor that causes the death of fish. In fisheries models natural mortality is denoted by (M).Sparre, P.; Ursin E.and Venema S. C. (1989). Introduction to tropical fish stock assessment. Part 1- Manual. FAO Fisheries Technical Paper No. 3061. Rome, FAO. p. 337. * Fishing mortality: the removal of fish from the stock due to fishing activities using any fishing gear. It is denoted by (F) in fisheries models. (M) and (F) are additive instantaneous rates that sum up to (Z), the instantaneous total mortality coefficient; that is, Z=M+F.Gulland, J.A. (1969). Manual of Methods for fish stock assessment. Part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lethargy
Lethargy is a state of tiredness, sleepiness, weariness, fatigue, sluggishness or lack of energy. It can be accompanied by depression, decreased motivation, or apathy. Lethargy can be a normal response to inadequate sleep, overexertion, overworking, stress, lack of exercise, improper nutrition, boredom, or a symptom of an underlying illness or a disorder. It may also be a side-effect of medication or caused by an interaction between medications or medication(s) and alcohol. It may also be an altered level of consciousness. When part of a normal response, lethargy often resolves with rest, adequate sleep, decreased stress, physical exercise, and good nutrition. Lethargy's symptoms however can last days or even months, so it can be a sign of a recent underlying illness or infection if it doesn't resolve normally. See also * Clinical depression * Encephalitis lethargica * Sleep apnea * Sleep deprivation * Somnolence Somnolence (alternatively sleepiness or drowsiness) is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
