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42
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[Original]
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Seasonal Changes in Earthworm Movement to the Surface of the Ground
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Masahiko OHNO
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Many earthworms often move to the surface of the ground and die there. In order to know the seasonal changes in this behavior, earthworms were collected daily in a paved area of Tokyo from May 1998 to July 1999. Four species: Pheretima hilgendorfi, P. aokii, P. agrestis and P. heteropoda, were identified. Juvenile earthworms as well as adult ones were collected. The mass appearances occurred mainly in or after heavy rains. The pH of rain seemed to P. hilgendorfi whose threshold pH value is bout 3.5. Some appearances were observed in November, a continuously sunny season, suggesting that their behavior is attributable to the increase of carbon dioxide in soil after rain, a traditional hypothesis, but also to other factors.
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earthworm, appearance, seasonal change, rain
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| Ann.Rep.Tokyo Metr.Inst.P.H., 58,
267-271,
2007 |
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43
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[Original]
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Surveys of Protozoan Parasites and Faecal Indicator Bacteria in Raw and Finished Water (Apr. 2005 - Mar. 2007)
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Akiko INOMATA, Chieko MUTO and Mitsugu HOSAKA
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Cryptosporidium, Giardia, raw water, finished water, faecal indicator bacteria
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| Ann.Rep.Tokyo Metr.Inst.P.H., 58,
273-277,
2007 |
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44
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[Information]
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Detection of Legionella Species from Bath Water and Pool Water in Tama Area, Tokyo (Apr. 2005 - Mar. 2007)
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Kumiko KUSUNOKI, Takeshi ISHIKAMI, Machiko JIN
and Mitsugu HOSAKA
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Legionella species, public bath, bath water, pool water, free residual chlorine
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| Ann.Rep.Tokyo Metr.Inst.P.H., 58,
279-284,
2007 |