User:Samsara/PortalBioColour

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Chromatophores are pigment-containing and light-reflecting cells found in amphibians, fish, reptiles, crustaceans, and cephalopods. They are largely responsible for generating skin and eye colour in cold-blooded animals and are generated in the neural crest during embryonic development. Mature chromatophores are grouped into subclasses based on their colour (more properly "hue") under white light: xanthophores (yellow), erythrophores (red), iridophores (reflective / iridescent), leucophores (white), melanophores (black/brown) and cyanophores (blue). The term can also refer to coloured, membrane associated vesicles found in some forms of photosynthetic bacteria.

Some species can rapidly change colour through mechanisms that translocate pigment and reorient reflective plates within chromatophores. This process, often used as a type of camouflage, is called physiological colour change. Cephalopods such as octopus have complex chromatophore organs controlled by muscles to achieve this, while vertebrates such as chameleons generate a similar effect by cell signaling. Such signals can be hormones or neurotransmitters and may be initiated by changes in mood, temperature, stress or visible changes in local environment.

Unlike cold-blooded animals, mammals and birds have only one class of chromatophore-like cell type: the melanocyte. The cold-blooded equivalent, melanophores, are studied by scientists to understand human disease and used as a tool in drug discovery.

Did you know... edit

• ...that a prokaryotic cytoskeleton has been found in prokaryote organisms by recent advances in visualization technology?
• ...that the Champawat tigress and the Tsavo lions had suffered injuries that disabled them from pursuing their natural prey, leading them to become man-eaters?
• ...that the aphid Brevicoryne brassicae has been called a "walking mustard oil bomb" due to its use of glucosinolates as a chemical defense mechanism against predators?

• ...that the 1984 Rajneeshee bioterror attack was the first bioterrorism attack in the United States, and one of only two confirmed terrorist uses of biological weapons to harm humans?
• ...that Florida has over 20 official state symbols, including a state soil and a state wildflower?
• ...that Adenovirus serotype 14 is an emerging virus, related to the common cold, that has recently caused 10 deaths in the United States, including at least one healthy young adult?
• ...that three out of every seventy-seven rainbow runners (pictured) have five spines rather than the normal six?

...Archive

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WikiProjects connected with biology:

• Conservation worldwide
• Ecology
  • Extinction
• Ecoregions
• Evolutionary biology
  • Game theory
• Genetics
• History of Science
• Marine life
• Medicine
• Microbiology
• Molecular and Cellular Biology
• Neuroscience
• Tree of Life
  • Prokaryotes and Protists
  • Plants
  • Arthropods
  • Cephalopods
  • Gastropods
  • Fishes
  • Amphibians and Reptiles
  • Birds
  • Mammals
  • Viruses

A complete list of scientific WikiProjects can be found here. See also Wikispecies, a Wikimedia project dedicated to classification of biological species.