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The idea of a tooth worm is a theory of the cause of dental caries, periodontitis and toothaches. Once widespread, the belief is now obsolete, having been superseded by more scientific rationales. It was supposed that the disease was caused by small worms resident within the tooth, eating it away. [1]
Most organisms involved in water purification originate from the waste, wastewater or water stream itself or arrive as resting spore of some form from the atmosphere. In a very few cases, mostly associated with constructed wetlands , specific organisms are planted to maximise the efficiency of the process.
Limnodrilus hoffmeisteri is conveyor-belt feeder that ingests particles in deep sediments and egests them on the sediment surface in the form of pseudofeces. [5] [6] The activities of this worm can alter sediment stratification, [6] [7] [8] increase the water content and porosity of sediment, [9] change the distribution of sediment particle size, [6] [10] alter the oxygen and nutrient dynamics ...
Microorganisms make up about 70% of the marine biomass. [4] A microorganism, or microbe, is a microscopic organism too small to be recognised adequately with the naked eye. In practice, that includes organisms smaller than about 0.1 mm. [12]: 13
Water pollution Exposure to synthetic estrogen as used in contraceptive medicines, which may enter freshwater ecosystems from municipal wastewater , can affect leeches' reproductive systems. Although not as sensitive to these compounds as fish, leeches showed physiological changes after exposure, including longer sperm sacs and vaginal bulbs ...
There are a few solid ways to do so, most of which include placing the worm in a container (while wearing gloves, of course) and either filling that container with a substance or placing it in an ...
Hallucigenia is a genus of lobopodian known from Cambrian aged fossils in Burgess Shale-type deposits in Canada and China, and from isolated spines around the world. [4] The generic name reflects the type species' unusual appearance and eccentric history of study; when it was erected as a genus, H. sparsa was reconstructed as an enigmatic animal upside down and back to front. [1]
The cilia allow the worms to glide along in the water between sand grains, although they also use muscles, allowing the body to twist or contract, for movement. They have no body cavity, and no circulatory or respiratory system. The nervous system is simple, and restricted to the outer layers of the body wall.