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Fisheries-induced Evolution
Fisheries-induced evolution (FIE) is the microevolution of an exploited aquatic organism's population, brought on through the artificial selection for biological traits by fishing practices (fishing techniques and fisheries management). Fishing, of any severity or effort, will impose an additional layer of mortality to the natural population equilibrium and will be selective to certain genetic traits within that organism's gene pool. This removal of selected traits fundamentally changes the population gene frequency, resulting in the artificially induced microevolution by the proxy of the survival of untargeted fish and their propagation of heritable biological characteristics. This artificial selection often counters natural life-history pattern for many species, such as causing early sexual maturation, diminished sizes for matured fish, and reduced fecundity in the form of smaller egg size, lower sperm counts and viability during reproductive events. These effects can have pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Net Fishing Professionally 0544990019 DORON
Net or net may refer to: Mathematics and physics * Net (mathematics), a filter-like topological generalization of a sequence * Net, a linear system of divisors of dimension 2 * Net (polyhedron), an arrangement of polygons that can be folded up to form a polyhedron * An incidence structure consisting of points and parallel classes of lines * Operator algebras in Local quantum field theory The Haag–Kastler axiomatic framework for quantum field theory, introduced by , is an application to local quantum physics of C*-algebra theory. Because of this it is also known as algebraic quantum field theory (AQFT). The axioms are stated in t ... Others * Net (command), an operating system command * Net (device), a grid-like device or object such as that used in fishing or sports, commonly made from woven fibers * Net (film), ''Net'' (film), 2021 Indian thriller drama film * Net (textile), a textile in which the warp and weft yarns are looped or knotted at their intersections * Net (ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blacktip Reef Shark
The blacktip reef shark (''Carcharhinus melanopterus'') is a species of requiem shark, in the family Carcharhinidae, which can be easily identified by the prominent black tips on its fins (especially on the first dorsal fin and its caudal fin). Among the most abundant sharks inhabiting the tropical coral reefs of the Indian and Pacific Oceans, this species prefers shallow, inshore waters. Its exposed first dorsal fin is a common sight in the region. The blacktip reef shark is usually found over reef ledges and sandy flats, though it has also been known to enter brackish and freshwater environments. It typically attains a length of . The blacktip reef shark has extremely small home ranges and exhibits strong site fidelity, remaining within the same local area for up to several years at a time. It is an active predator of small bony fishes, cephalopods, and crustaceans, and has also been known to feed on sea snakes and seabirds. Accounts of the blacktip reef shark's life history ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainbow Trout
The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coastal rainbow trout or Columbia River redband trout that usually returns to freshwater to spawn after living two to three years in the ocean. Freshwater forms that have been introduced into the Great Lakes and migrate into tributaries to spawn are also called steelhead. Adult freshwater stream rainbow trout average between , while lake-dwelling and anadromous forms may reach . Coloration varies widely based on subspecies, forms, and habitat. Adult fish are distinguished by a broad reddish stripe along the lateral line, from gills to the tail, which is most vivid in breeding males. Wild-caught and hatchery-reared forms of the species have been transplanted and introduced for food or sport in at least 45 countries and every continent except ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Experimental Evolution
Experimental evolution is the use of laboratory experiments or controlled field manipulations to explore evolutionary dynamics. Evolution may be observed in the laboratory as individuals/populations adapt to new environmental conditions by natural selection. There are two different ways in which adaptation can arise in experimental evolution. One is via an individual organism gaining a novel beneficial mutation. The other is from allele frequency change in standing genetic variation already present in a population of organisms. Other evolutionary forces outside of mutation and natural selection can also play a role or be incorporated into experimental evolution studies, such as genetic drift and gene flow. The organism used is decided by the experimenter, based on the hypothesis to be tested. Many generations are required for adaptive mutation to occur, and experimental evolution via mutation is carried out in viruses or unicellular organisms with rapid generation times, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trawling
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different species of fishes or sometimes targeted species. Trawls are often called towed gear or dragged gear. The boats that are used for trawling are called trawlers or draggers. Trawlers vary in size from small open boats with as little as 30 hp (22 kW) engines to large factory trawlers with over 10,000 hp (7.5 MW). Trawling can be carried out by one trawler or by two trawlers fishing cooperatively (pair trawling). Trawling can be contrasted with trolling. While trawling involves a net and is typically done for commercial usage, trolling instead involves a reed, rod and a bait or a lure and is typically done for recreational purposes. Trawling is also commonly used as a scientific sampling, or survey, method. Bottom vs. midwater trawling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gillnetting
Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is generally referred to as a "cork line." The line along the bottom of the panels is generally weighted. Traditionally this line has been weighted with lead and may be referred to as "lead line." A gillnet is normally set in a straight line. Gillnets can be characterized by mesh size, as well as colour and type of filament from which they are made. Fish may be caught by gillnets in three ways: # Wedged – held by the mesh around the body. # Gilled – held by mesh slipping behind the opercula. # Tangled – held by teeth, spines, maxillaries, or other protrusions without the body penetrating the mesh. Most often fish are gilled. A fish swims into a net and passes only part way through the mesh. When it struggles to free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transplant Experiment
A transplant experiment, is an experiment to test the effect of environment by moving two species from their native environments into a common environment. The name was originally applied to experiments on plants, but is now equally applied to animals such as lizards and ants, and other organisms. A reciprocal transplant experiment involves introducing organisms from each of two environments into the other; the approach can be extended to more than two environments if required. Transplant experiments are often used to test if there is a genetic component to differences in populations. Advances in molecular biology have provided researchers with the ability to study genetic variation more directly. However, transplant experiments still have the advantages of being simple and requiring little technology. On the other hand, they may require considerable time and labour, and the number of test organisms is often relatively limited. Common garden methods can be improved by combining ev ... [...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] |
Amphiprioninae
Clownfish or anemonefish are fishes from the subfamily Amphiprioninae in the family Pomacentridae. Thirty species of clownfish are recognized: one in the genus ''Premnas'', while the remaining are in the genus ''Amphiprion''. In the wild, they all form symbiotic mutualisms with sea anemones. Depending on the species, anemonefish are overall yellow, orange, or a reddish or blackish color, and many show white bars or patches. The largest can reach a length of , while the smallest barely achieve . Distribution and habitat Anemonefish are endemic to the warmer waters of the Indian Ocean, including the Red Sea, and Pacific Ocean, the Great Barrier Reef, Southeast Asia, Japan, and the Indo-Malaysian region. While most species have restricted distributions, others are widespread. Anemonefish typically live at the bottom of shallow seas in sheltered reefs or in shallow lagoons. No anemonefish are found in the Atlantic. Diet Anemonefish are omnivorous and can feed on undigested food ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Anemone
Sea anemones are a group of predation, predatory marine invertebrates of the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and ''hydra (genus), Hydra''. Unlike jellyfish, sea anemones do not have a Jellyfish#Life history and behavior, medusa stage in their life cycle. A typical sea anemone is a single polyp (zoology), polyp attached to a hard surface by its base, but some species live in soft sediment, and a few float near the surface of the water. The polyp has a columnar trunk topped by an oral disc with a ring of tentacles and a central mouth. The tentacles can be retracted inside the body cavity or expanded to catch passing prey. They are armed with cnidocytes (stinging cells). In many species, additional n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coral
Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton. A coral "group" is a colony of very many genetically identical polyps. Each polyp is a sac-like animal typically only a few millimeters in diameter and a few centimeters in height. A set of tentacles surround a central mouth opening. Each polyp excretes an exoskeleton near the base. Over many generations, the colony thus creates a skeleton characteristic of the species which can measure up to several meters in size. Individual colonies grow by asexual reproduction of polyps. Corals also breed sexually by spawning: polyps of the same species release gametes simultaneously overnight, often around a full moon. Fertilized eggs form planulae, a mobile early form of the coral polyp which, when m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitetip Reef Shark
The whitetip reef shark (''Triaenodon obesus'') is a species of requiem shark, in the family Carcharhinidae, and the only member of its genus. A small shark that does not usually exceed in length, this species is easily recognizable by its slender body and short but broad head, as well as tubular skin flaps beside the nostrils, oval eyes with vertical pupils, and white-tipped dorsal and caudal fins. One of the most common sharks found on Indo-Pacific coral reefs, the whitetip reef shark occurs as far west as South Africa and as far east as Central America. It is typically found on or near the bottom in clear water, at a depth of . During the day, whitetip reef sharks spend much of their time resting inside caves. Unlike other requiem sharks, which rely on ram ventilation and must constantly swim to breathe, this shark can pump water over its gills and lie still on the bottom. At night, whitetip reef sharks emerge to hunt bony fishes, crustaceans, and octopus in groups, their elo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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