Rapid cold hardening in Antarctic microarthropods
Worland, M.R.; Convey, P.. 2001 Rapid cold hardening in Antarctic microarthropods. Functional Ecology, 15 (4). 515-524. 10.1046/j.0269-8463.2001.00547.xFull text not available from this repository.
1 Rapid cold hardening was examined in three common Antarctic microarthropods using differential scanning calorimetry over timescales between 3 and 30 h, under field and controlled laboratory conditions. 2 In fresh field samples and cultures of the springtail, Cryptopygus antarcticus (Willem), and cultures of the mites, Alaskozetes antarcticus (Michael) and Halozetes belgicae (Michael), maintained under summer field-simulating conditions, supercooling point (SCP) distributions tracked microhabitat temperature variation over the observation period. 3 Controlled acclimation of samples of summer-acclimatized C. antarcticus caused significant cold hardening after 12 h at temperatures around 0 °C (+3 to −2 °C). No response was obtained at higher or lower temperatures, or in field-fresh winter-acclimatized animals. The latter did not lose cold hardiness when held at positive temperatures for 12 h. 4 Gradual cooling of C. antarcticus over 20 h from +5 to −5 °C caused a considerable increase in cold tolerance. Rewarming partially but non-significantly reversed this effect. The greatest response occurred between +3 and +1 °C. Maximum faecal pellet production also occurred in this interval, but gut clearance alone was not sufficient to explain observed cold hardening. 5 It is hypothesized that these species possess a hitherto unrecognized capacity to alter cold hardiness in summer in response to environmental temperature cues over a shorter timescale than previously thought, by a mechanism that relies on neither gut clearance nor concentration of body fluids via water loss. This ability may reduce the developmental costs of premature entry into an inactive, cold-hardy state.
|Programmes:||BAS Programmes > Antarctic Science in the Global Context (2000-2005) > Life at the Edge - Stresses and Thresholds|
|Additional Keywords:||Cold tolerance, collembola, differential scanning calorimeter, gut clearance, mite|
|Date made live:||14 Nov 2012 10:11|
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