Thermotaxis is a behavior in which an organism directs its locomotion up or down a gradient of temperature.
Lab research has determined that some
slime molds
Slime mold or slime mould is an informal name given to several kinds of unrelated eukaryotic organisms with a life cycle that includes a free-living single-celled stage and the formation of spores. Spores are often produced in macroscopic mu ...
and small
nematodes
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broa ...
(namely
Meloidogyne incognita
''Meloidogyne incognita'' (root-knot nematode - RKN), also known as the "southern root-nematode" or "cotton root-knot nematode" is a plant-parasitic roundworm in the family Heteroderidae. This nematode is one of the four most common species world ...
) can migrate along amazingly shallow temperature gradients of less than 0.1C/cm and sometimes as low as 0.001C/cm. Theoretical analysis indicates that even this impressive feat is far from pushing the limits set by thermal noise. The natural environment always contains temperature gradients that organisms could respond to, if it were useful. The response of the slime mold and nematode is complicated and thought to allow them to move toward an appropriate level in soil.
[Dusenbery, David B. (1996). “Life at Small Scale”, pp. 101-109. Scientific American Library, New York. .] Recent research suggests that mammalian sperm employ thermotaxis to move to an appropriate location in the female's oviduct (see
Sperm guidance).
References
{{Taxes (Biology)
Taxes (biology)