Taxis

A taxis (plural taxes[1][2][3] /ˈtæksz/, from Ancient Greek τάξις (taxis), meaning 'arrangement'[4]) is the movement of an organism in response to a stimulus such as light or the presence of food. Taxes are innate behavioural responses. A taxis differs from a tropism (turning response, often growth towards or away from a stimulus) in that in the case of taxis, the organism has motility and demonstrates guided movement towards or away from the stimulus source.[5][6] It is sometimes distinguished from a kinesis, a non-directional change in activity in response to a stimulus.

Classification

Taxes are classified based on the type of stimulus, and on whether the organism's response is to move towards or away from the stimulus. If the organism moves towards the stimulus, the taxis is positive, while if it moves away, the taxis is negative. For example, flagellate protozoans of the genus Euglena move towards a light source. This reaction or behaviour is called "positive phototaxis", since phototaxis refers to a response to light, and the organism is moving towards the stimulus.

Many types of taxis have been identified, including aerotaxis (stimulation by oxygen) anemotaxis (by wind), barotaxis (by pressure), chemotaxis (by chemicals), durotaxis (by stiffness), electrotaxis or galvanotaxis (by electric current), gravitaxis (by gravity), hydrotaxis (by moisture), magnetotaxis (by magnetic field), phototaxis (by light), rheotaxis (by fluid flow), thermotaxis (by changes in temperature) and thigmotaxis (by physical contact).

Depending on the type of sensory organs present, a taxis can be classified as a klinotaxis, where an organism continuously samples the environment to determine the direction of a stimulus; a tropotaxis, where bilateral sense organs are used to determine the stimulus direction; and telotaxis, where a single organ suffices to establish the orientation of stimulus.

Examples

Terminology derived from taxis direction

There are five types of taxis based on the movement of organisms.

See also

References

  1. http://www.thefreedictionary.com/taxis
  2. http://www.merriam-webster.com/dictionary/taxis
  3. http://dictionary.reference.com/browse/taxis
  4. τάξις in A Greek–English Lexicon by Liddell & Scott, Clarendon Press, Oxford, 1940
  5. Kendeigh, S. C. (1961). Animal Ecology. Prentice-Hall, Inc., Englewood Cliffs, N.J. pp. 468 pp.
  6. Dusenbery, David B. (2009). Living at Micro Scale, Ch. 14. Harvard University Press, Cambridge, Mass. ISBN 978-0-674-03116-6.
  7. 1 2 3 4 5 6 Martin, E.A., ed. (1983). Macmillan Dictionary of Life Sciences (2nd ed.). London: Macmillan Press. p. 362. ISBN 0-333-34867-2.
  8. Blass, E.M (1987). "Opioids, sweets and a mechanism for positive affect: Broad motivational implications". In Dobbing, J. Sweetness. London: Springer-Verlag. pp. 115–124. ISBN 0-387-17045-6.
  9. Schweinitzer T, Josenhans C. Bacterial energy taxis: a global strategy? Arch Microbiol. 2010 Jul;192(7):507-20.
  10. C. F. Adams & A. J. Paul (1999). "Phototaxis and geotaxis of light-adapted zoeae of the golden king crab Lithodes aequispinus (Anomura: Lithodidae) in the laboratory". Journal of Crustacean Biology. 19 (1): 106–110. JSTOR 1549552. doi:10.2307/1549552.
  11. T. Fenchel & B. J. Finlay (1 May 1984). "Geotaxis in the ciliated protozoon Loxodes". Journal of Experimental Biology. 110 (1): 110–133.
  12. Dusenbery, David B. (2009). Living at Micro Scale, pp.164–167. Harvard University Press, Cambridge, Mass. ISBN 978-0-674-03116-6.
  13. Menzel, Randolf (1979). "Spectral Sensitivity and Color Vision in Invertebrates". In H. Autrum (editor). Comparative Physiology and Evolution of Vision in Invertebrates- A: Invertebrate Photoreceptors. Handbook of Sensory Physiology. VII/6A. New York: Springer-Verlag. pp. 503–580. See section D: Wavelength–Specific Behavior and Color Vision. ISBN 3-540-08837-7.
  14. Dusenbery, David B. (1992). Sensory Ecology, p.114. W.H. Freeman, New York. ISBN 0-7167-2333-6.
  15. Dusenbery, D.B. Behavioral Ecology and Sociobiology, 22:219–223 (1988). "Avoided temperature leads to the surface:…"
  16. Dusenbery, D.B. Biological Cybernetics, 60:431–437 (1989). "A simple animal can use a complex stimulus patter to find a location:…"
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