Tolerance to Anhydrobiotic Conditions Among Two Coexisting Tardigrade Species Differing in Life Strategies.

Water availability is one of the most important factors for terrestrial life. Terrestrial habitats may periodically become dry, which can be overcome by an organism's capability to undergo anhydrobiosis. In animals, this phenomenon has been reported for invertebrates, with tardigrades being the best-known. However, different tardigrade species appear to significantly differ in their anhydrobiotic abilities. While several studies have addressed this issue, established experimental protocols for tardigrade dehydration differ both within and among species, leading to ambiguous results. Therefore, we apply unified conditions to estimate intra-and interspecies differences in anhydrobiosis ability reflected by the return to active life. We analysed and representing predatory and herbivorous species, respectively, and often co-occur in the same habitat. The results indicated that the carnivorous displays better anhydrobiosis survivability than the herbivorous . This tendency to some degree coincides with the time of "waking up" since showed first movements and full activity of any first individual later than . The movements of all individuals were however observed to be faster for . Differences between the experimental groups varying in anhydrobiosis length were also observed: the longer tun state duration, the more time was necessary to return to activity.