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Inbreeding In Fish
Inbreeding in fish is the mating of closely related individuals, leading to an increase in homozygosity. Repeated inbreeding generally leads to morphological abnormalities and a reduction in fitness in the offspring. In the wild, fish have a number of ways to avoid inbreeding, both before and after spawning. Exposure Exposure of zebrafish to a chemical environmental agent, analogous to that caused by Human impact on the environment, anthropogenic pollution, amplified the effects of inbreeding on key reproductive traits. Embryo viability was significantly reduced in inbred exposed fish and there was a tendency for inbred males to sire fewer offspring. Effects The effect of inbreeding on reproductive behavior was studied in the Poeciliidae, poeciliid fish ''Heterandria formosa''. One generation of full-sib mating was found to decrease reproductive performance and likely reproductive success of male progeny. Other traits that displayed inbreeding depression were offspring viabili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zebrafish (26436913602)
The zebrafish (''Danio rerio'') is a species of freshwater Actinopterygii, ray-finned fish belonging to the Family (biology), family Danionidae of the Order (biology), order Cypriniformes. Native to South Asia, it is a popular aquarium, aquarium fish, frequently sold under the trade name zebra danio (and thus often called a "tropical fish" although it is both tropical and subtropical). The zebrafish is an important and widely used vertebrate model organism in scientific research, particularly developmental biology, but also gene function, oncology, teratology, and drug development, in particular pre-clinical development. It is also notable for its regeneration (biology), regenerative abilities, and has been genetically modified organism, modified by researchers to produce many transgenic strains. Taxonomy The zebrafish is a derived trait, derived member of the genus ''Brachydanio'', of the family Cyprinidae. It has a cladistics, sister-group relationship with ''Danio aesculapi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zebrafish
The zebrafish (''Danio rerio'') is a species of freshwater ray-finned fish belonging to the family Danionidae of the order Cypriniformes. Native to South Asia, it is a popular aquarium fish, frequently sold under the trade name zebra danio (and thus often called a " tropical fish" although it is both tropical and subtropical). The zebrafish is an important and widely used vertebrate model organism in scientific research, particularly developmental biology, but also gene function, oncology, teratology, and drug development, in particular pre-clinical development. It is also notable for its regenerative abilities, and has been modified by researchers to produce many transgenic strains. Taxonomy The zebrafish is a derived member of the genus '' Brachydanio'', of the family Cyprinidae. It has a sister-group relationship with '' Danio aesculapii''. Zebrafish are also closely related to the genus '' Devario'', as demonstrated by a phylogenetic tree of close species. Distri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Impact On The Environment
Human impact on the environment (or anthropogenic environmental impact) refers to changes to biophysical environments and to ecosystems, biodiversity, and natural resources caused directly or indirectly by humans. Modifying the environment to fit the needs of society (as in the built environment) is causing severe effects including global warming, environmental degradation (such as ocean acidification), mass extinction and biodiversity loss, ecological crisis, and ecological collapse. Some human activities that cause damage (either directly or indirectly) to the environment on a global scale include population growth, neoliberal economic policies and rapid economic growth, overconsumption, overexploitation, pollution, and deforestation. Some of the problems, including global warming and biodiversity loss, have been proposed as representing catastrophic risks to the survival of the human species. The term ''anthropogenic'' designates an effect or object resulting from h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inbreeding
Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely genetic distance, related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders and other consequences that may arise from expression of wikt:deleterious, deleterious dominance (genetics), recessive traits resulting from incestuous sexual relationships and consanguinity. Animals avoid inbreeding only rarely. Inbreeding results in homozygous, homozygosity which can increase the chances of offspring being affected by recessive phenotypic trait, traits. In extreme cases, this usually leads to at least temporarily decreased Fitness (biology), biological fitness of a population (called inbreeding depression), which is its ability to survive and reproduce. An individual who inherits such deleterious traits is colloquially referred to as ''inbred''. The avoidance of expression of such deleterious recessive allel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poeciliidae
Poeciliidae are a Family (biology), family of freshwater ray-finned fishes of the order Cyprinodontiformes, the tooth-carps, and include well-known live-bearing aquarium fish, such as the guppy, Poecilia, molly, Platy (fish), platy, and Green swordtail, swordtail. The original distribution of the family was the Southeastern United States to north of Río de la Plata, Argentina. Due to release of aquarium specimens and the widespread use of species of the genera ''Poecilia'' and ''Gambusia'' for mosquito control, though, introduced poeciliids can today be found in all tropical and subtropical areas of the world. In addition, ''Poecilia'' and ''Gambusia'' specimens have been identified in hot springs pools as far north as Banff, Alberta. Live-bearing All species in the Poecilidae are live-bearers. Differences are seen in the mode and degree of support the female gives the developing larvae. Many members of the family Poeciliidae are considered to be lecithotrophic (the mother prov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inbreeding Depression
Inbreeding depression is the reduced biological fitness caused by loss of genetic diversity as a consequence of inbreeding, the breeding of individuals closely related genetically. This loss of genetic diversity results from small population size, often stemming from a population bottleneck. Biological fitness refers to an organism's ability to survive and perpetuate its genetic material. In general, the higher the genetic variation or gene pool within a breeding population, the less likely it is to suffer from inbreeding depression, though inbreeding and outbreeding depression can simultaneously occur. Inbreeding depression seems to be present in most populations of organisms, but varies across mating systems. Remarkably, hermaphroditic species often exhibit lower degrees of inbreeding depression than outcrossing species, as repeated generations of selfing is thought to purge deleterious alleles from populations. For example, the outcrossing nematode (roundworm) '' Caen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coho Salmon
The coho salmon (''Oncorhynchus kisutch;'' Karuk: achvuun) is a species of anadromous fish in the salmon family (biology), family and one of the five Pacific salmon species. Coho salmon are also known as silver salmon (or "silvers") and is often sold as medium red salmon. The scientific species name is based on the Russian language, Russian common name ''kizhuch'' (кижуч). Description During their ocean phase, coho salmon have silver sides and dark-blue backs with spots on their back and upper tail lobe. During their spawning phase, their jaws and teeth become hooked. After entering fresh water, they develop bright-red sides, bluish-green heads and backs, dark bellies and dark spots on their backs. Sexually maturing fish develop a light-pink or rose shading along the belly, and the males may show a slight arching of the back. Mature adults have a pronounced red skin color with darker backs and spots, with females having darker shades than males. Coho salmon average 20 to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inbreeding Avoidance
Inbreeding avoidance, or the inbreeding avoidance hypothesis, is a concept in evolutionary biology that refers to the prevention of the harmful effects of inbreeding. The inbreeding avoidance hypothesis posits that certain mechanisms develop within a species, or within a given population of a species, as a result of assortative mating and natural selection, natural and sexual selection, in order to prevent breeding among related individuals. Although inbreeding may impose certain evolutionary costs, inbreeding avoidance, which limits the number of potential mates for a given individual, can inflict opportunity costs. Therefore, a balance exists between inbreeding and inbreeding avoidance. This balance determines whether inbreeding mechanisms develop and the specific nature of such mechanisms. Inbreeding can result in inbreeding depression, which is the reduction of Fitness (biology), fitness of a given population due to inbreeding. Inbreeding depression occurs via appearance of di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mangrove Killifish
The mangrove rivulus or mangrove killifish, ''Kryptolebias marmoratus'' ( syn. ''Rivulus marmoratus''), is a species of killifish in the family Rivulidae. It lives in brackish and marine waters (less frequently in fresh water) along the coasts of Florida, through the Antilles, and along the eastern and northern Atlantic coasts of Mexico, Central America and South America (south to Brazil). It has a very wide tolerance of both salinity (0–68 ‰)Bester, CMangrove Rivulus.Florida Museum. Retrieved 6 May 2017. and temperature (),Hill, K Smithsonian Marine Station at Fort Pierce. Retrieved 6 May 2017. can survive for about two months on land, and mostly breeds by self-fertilization. It is typically found in areas with red mangrove and sometimes lives in burrows of ''Cardisoma guanhumi'' crabs. The mangrove rivulus is up to long, but most individuals are . Overall the mangrove rivulus is widespread and not threatened, but in the United States it is considered a Species of Concern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mangrove Rivulus
The mangrove rivulus or mangrove killifish, ''Kryptolebias marmoratus'' (syn. ''Rivulus marmoratus''), is a species of killifish in the Family (biology), family Rivulidae. It lives in brackish and marine waters (less frequently in fresh water) along the coasts of Florida, through the Antilles, and along the eastern and northern Atlantic coasts of Mexico, Central America and South America (south to Brazil). It has a very wide tolerance of both salinity (0–68 ‰)Bester, CMangrove Rivulus.Florida Museum. Retrieved 6 May 2017. and temperature (),Hill, K Smithsonian Marine Station at Fort Pierce. Retrieved 6 May 2017. can survive for about two months on land, and mostly breeds by self-fertilization. It is typically found in areas with Rhizophora mangle, red mangrove and sometimes lives in burrows of ''Cardisoma guanhumi'' crabs. The mangrove rivulus is up to long, but most individuals are . Overall the mangrove rivulus is widespread and not threatened, but in the United States it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiosis
Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one copy of each chromosome (haploid). Additionally, prior to the division, genetic material from the paternal and maternal copies of each chromosome is crossed over, creating new combinations of code on each chromosome. Later on, during fertilisation, the haploid cells produced by meiosis from a male and a female will fuse to create a zygote, a cell with two copies of each chromosome. Errors in meiosis resulting in aneuploidy (an abnormal number of chromosomes) are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells, each with half the number of chromosomes as the original parent cell. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
