Adaptations for the maintenance of water balance by three species of Antarctic mites

摘要: Three species of Antarctic mites, Alaskozetes antarcticus, Hydrogamasellus antarcticus and Rhagidia gerlachei, are abundant in the vicinity Palmer Station, Antarctica. No single mechanism for reducing water stress was shared by all three species. A. R. gerlachei (both ca. 200 μg) over twice as large H. (ca. 90 μg), but had similar body content (67%) tolerated a loss up to 35% their before succumbing dehydration. All imbibed free capacity reduce behaviorally forming clusters. distinct that it relied heavily on conservation (xerophilic classification) largely achieved its thick cuticular armor, feature members this suborder (Oribatida), hydrocarbons. In comparison other two species, coated with 2–3× amount hydrocarbons, 20-fold reduction net transpiration rate, critical transition temperature (CTT) indicates pronounced suppression activation energy (E a) at temperatures below 25°C. contrast, lack CTT, have lower amounts hydrocarbons low E high rates, classifying them hydrophilic. Only capable utilizing vapor replenish stores, could do so only relative humidities close saturation (95–98 %RH). Thus, require wet habitats counter loss, replace lost through predation. Compared mites from temperate zone, content, commonly enhances cold tolerance.