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Bolti
The Nile tilapia (''Oreochromis niloticus'') is a species of tilapia, a cichlid occurring naturally in parts of Africa (such as its namesake Nile River) and the Levant, though numerous introduced populations exist outside its natural range. This current wide range is caused by its high commercial value as a food fish, where it is marketed as mango fish (not to be confused with the mango tilapia, or ''Sarotherodon galilaeus''), nilotica, or boulti, along with many other names, both local and foreign. Due to its value, the Nile tilapia is widely aquacultured across the world due to its hardiness and a mode of reproduction conducive to mass rearing, namely mouthbrooding, and various attempts have been made to increase production yields, including hybridization with other tilapias. Description The Nile tilapia reaches up to in length, and can exceed . As typical of tilapia, males reach a larger size and grow faster than females. Wild, natural-type Nile tilapias are brownish o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wild Type
The wild type (WT) is the phenotype of the typical form of a species as it occurs in nature. Originally, the wild type was conceptualized as a product of the standard "normal" allele at a locus, in contrast to that produced by a non-standard, " mutant" allele. "Mutant" alleles can vary to a great extent, and even become the wild type if a genetic shift occurs within the population. Continued advancements in genetic mapping technologies have created a better understanding of how mutations occur and interact with other genes to alter phenotype. It is now regarded that most or all gene loci exist in a variety of allelic forms, which vary in frequency throughout the geographic range of a species, and that a uniform wild type does not exist. In general, however, the most prevalent allele – i.e., the one with the highest gene frequency – is the one deemed wild type. The concept of wild type is useful in some experimental organisms such as fruit flies ''Drosophila melanogaster'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tilapia As Exotic Species
Throughout much of the tropics, tilapiine cichlids native to Africa and the Levant have been widely introduced into a variety of aquatic systems. In the U.S. states of Florida and Texas, tilapia were originally introduced to curtail invasive plants. In an effort to meet the growing demand for tilapia, humans have farmed these fish in countries around the world. Capable of establishing themselves into new ponds and waterways, many tilapia have escaped aquaculture facilities across much of Asia, Africa, and South America. In other cases, tilapia have been established into new aquatic habitats via aquarists or ornamental fish farmers. Because tilapia are generally large, fast growing, breed rapidly, and can tolerate a wide variety of water conditions (even marine environments), tilapia establish themselves into new habitats rather quickly. In doing so, tilapia often out compete native fish, create turbidity in rivers by digging, and can reduce available sun light for aquatic plants. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selectively Bred
Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant males and females will sexually reproduce and have offspring together. Domesticated animals are known as breeds, normally bred by a professional breeder, while domesticated plants are known as varieties, cultigens, cultivars, or breeds. Two purebred animals of different breeds produce a crossbreed, and crossbred plants are called hybrids. Flowers, vegetables and fruit-trees may be bred by amateurs and commercial or non-commercial professionals: major crops are usually the provenance of the professionals. In animal breeding artificial selection is often combined with techniques such as inbreeding, linebreeding, and outcrossing. In plant breeding, similar methods are used. Charles Darwin discussed how selective breeding had been success ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meristics
Meristics is an area of zoology and botany which relates to counting quantitative features of animals and plants, such as the number of fins or scales in fish. A meristic (countable trait) can be used to describe a particular species, or used to identify an unknown species. Meristic traits are often described in a shorthand notation called a ''meristic formula''. Meristic characters are the countable structures occurring in series (e.g. myomeres, vertebrae, fin rays). These characters are among the characters most commonly used for differentiation of species and populations. In the salmonids, scale counts have been most widely used for the differentiation of populations within species. In rainbow and steelhead trout the most notable differences among populations occur in counts of scales. Meristic comparison is used in phenetic and cladistic analysis. Meristic analysis A meristic study is often a difficult task. For example, counting the features of a fish is not as easy as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsal Fin
A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found in most fish, in mammals such as whales, and in extinct ancient marine reptiles such as ichthyosaurs. Most have only one dorsal fin, but some have two or three. Wildlife biologists often use the distinctive nicks and wear patterns which develop on the dorsal fins of whales to identify individuals in the field. The bones or cartilages that support the dorsal fin in fish are called pterygiophores. Functions The main purpose of the dorsal fin is usually to stabilize the animal against rolling and to assist in sudden turns. Some species have further adapted their dorsal fins to other uses. The sunfish uses the dorsal fin (and the anal fin Fins are moving appendages protruding from the body of fish that interact with water to ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blue Tilapia
The blue tilapia (''Oreochromis aureus'') is a species of tilapia, a fish in the family Cichlidae. Native to Northern and Western Africa, and the Middle East, through introductions it is now also established elsewhere, including parts of the United States, where it has been declared an invasive species and has caused significant environmental damage. It is known as the blue kurper in South Africa. Description In their introduced US range, blue tilapia are usually in length, and reach weights up to . The largest recorded specimen was more than long and weighed more than . Blue tilapia are mouthbrooders, and broods range from 160 to 1600 eggs per female. ''O. aureus'' is primarily herbivorous, but occasionally consumes zooplankton; the young include small invertebrates in their diet. Range and habitat The blue tilapia is native to Northern and Western Africa, and the Middle East. In Africa, it is native to the Senegal, Niger, Benue and lower Nile Rivers. In the Middle East, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breeding Season
Seasonal breeders are animal species that successfully mate only during certain times of the year. These times of year allow for the optimization of survival of young due to factors such as ambient temperature, food and water availability, and changes in the predation behaviors of other species. Related sexual interest and behaviors are expressed and accepted only during this period. Female seasonal breeders will have one or more estrus cycles only when she is "in season" or fertile and receptive to mating. At other times of the year, they will be anestrus, or have a dearth of their sexual cycle. Unlike reproductive cyclicity, seasonality is described in both males and females. Male seasonal breeders may exhibit changes in testosterone levels, testes weight, and fertility depending on the time of year. Seasonal breeders are distinct from opportunistic breeders, that mate whenever the conditions of their environment become favorable, and continuous breeders that mate year-roun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grayish
Variations of gray or grey include achromatic grayscale shades, which lie exactly between white and black, and nearby colors with low colorfulness. A selection of a number of these various colors is shown below. Chart of computer web color grays Below is a chart showing the computer web color grays. An ''achromatic gray'' is a gray color in which the red, green, and blue codes are exactly equal. The web colors ''gray'', ''gainsboro'', ''light gray'', ''dark gray'', and ''dim gray'' are all achromatic colors. A ''chromatic gray'' is a gray color in which the red, green, and blue codes are not exactly equal, but are close to each other, which is what makes it a shade of gray. White and black The colors white and black are not usually thought of as shades of gray, but they can be thought of as shades of achromatic gray, as both contain equal amounts of red, blue and green. White is at the extreme upper end of the achromatic value scale and black is at the extreme lower end of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brownish
Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing and painting, brown is usually made by combining the colors orange and black. In the RGB color model used to project colors onto television screens and computer monitors, brown combines red and green. The color brown is seen widely in nature, wood, soil, human hair color, eye color and skin pigmentation. Brown is the color of dark wood or rich soil. In the RYB color model, brown is made by mixing the three primary colors, red, yellow, and blue. According to public opinion surveys in Europe and the United States, brown is the least favorite color of the public; it is often associated with fecal matter, plainness, the rustic, although it does also have positive associations, including baking, warmth, wildlife, the autumn and music. Etymology The term is from Old English , in origin for any dusky or dark shade of color. The first re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mouthbrooding
Mouthbrooding, also known as oral incubation and buccal incubation, is the care given by some groups of animals to their offspring by holding them in the mouth of the parent for extended periods of time. Although mouthbrooding is performed by a variety of different animals, such as the Darwin's frog, fish are by far the most diverse mouthbrooders. Mouthbrooding has evolved independently in several different families of fish. Mouthbrooding behaviour Paternal mouthbrooders are species where the male looks after the eggs. Paternal mouthbrooders include the arowana, various mouthbrooding bettas and gouramies such as '' Betta pugnax'', and sea catfish such as '' Ariopsis felis''. Among cichlids, paternal mouthbrooding is relatively rare, but is found among some of the tilapiines, most notably the black-chin tilapia '' Sarotherodon melanotheron''. In the case of the maternal mouthbrooders, the female takes the eggs. Maternal mouthbrooders are found among both African and South American ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hatchery
A hatchery is a facility where eggs are hatched under artificial conditions, especially those of fish, poultry or even turtles. It may be used for ''ex situ'' conservation purposes, i.e. to breed rare or endangered species under controlled conditions; alternatively, it may be for economic reasons (i.e. to enhance food supplies or fishery resources). Fish hatcheries Fish hatcheries are used to cultivate and breed a large number of fish in an enclosed environment. Fish farms use hatcheries to cultivate fish to sell for food, or ornamental purposes, eliminating the need to find the fish in the wild and even providing some species outside their natural season. They raise the fish until they are ready to be eaten or sold to aquarium stores. Other hatcheries release the juvenile fish into a river, lake or the ocean to support commercial, tribal, or recreational fishing or to supplement the natural numbers of threatened or endangered species, a practice known as fish stocking. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquaculture Of Tilapia
Tilapia has become the third most important fish in aquaculture after carp and salmon; worldwide production exceeded in 2002 and increases annually. Because of their high protein content, large size, rapid growth (6 to 7 months to grow to harvest size), and palatability, a number of coptodonine and oreochromine cichlids—specifically, various species of '' Coptodon'', '' Oreochromis'', and '' Sarotherodon''—are the focus of major aquaculture efforts. Tilapia fisheries originated in Africa and the Levant. The accidental and deliberate introductions of tilapia into South and Southeast Asian freshwater lakes have inspired outdoor aquaculture projects in various countries with tropical climates, including Honduras, Papua New Guinea, the Philippines, and Indonesia. Tilapia farm projects in these countries have the highest potential to be "green" or environmentally friendly. In temperate zone localities, tilapia farmers typically need a costly energy source to maintain a tropica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
