Jönsson K Ingemar, Rebecchi Lorena
Department of Theoretical Ecology, University of Lund, Ecology Building, S-223 62 Lund, Sweden.
J Exp Zool. 2002 Nov 1;293(6):578-84. doi: 10.1002/jez.10186.
The ability of some animal taxa (e.g., nematodes, rotifers, and tardigrades) to enter an ametabolic (cryptobiotic) state is well known. Nevertheless, the phenotypic factors affecting successful anhydrobiosis have rarely been investigated. We report a laboratory study on the effects of body size, reproductive condition, and energetic condition on anhydrobiotic survival in a population of the eutardigrade Richtersius coronifer. Body size and energetic condition interacted in affecting the probability of survival, while reproductive condition had no effect. Large tardigrades had a lower probability of survival than medium-sized tardigrades and showed a positive response in survival to energetic condition. This suggests that energy constrained the possibility for large tardigrades to enter and to leave anhydrobiosis. As a possible alternative explanation for low survival in the largest specimens we discuss the expression of senescence. In line with the view that processes related to anhydrobiosis are connected with energetic costs we documented a decrease in the size of storage cells over a period of anhydrobiosis, showing for the first time that energy is consumed in the process of anhydrobiosis in tardigrades.
一些动物类群（如线虫、轮虫和缓步动物）进入无代谢（隐生）状态的能力是众所周知的。然而，影响成功脱水生活的表型因素却很少被研究。我们报告了一项关于体型、生殖状态和能量状态对富氏高生熊虫种群脱水生活存活影响的实验室研究。体型和能量状态在影响存活概率方面相互作用，而生殖状态则没有影响。大型缓步动物的存活概率低于中型缓步动物，并且在存活方面对能量状态表现出积极反应。这表明能量限制了大型缓步动物进入和脱离脱水生活的可能性。作为对最大标本中低存活率的一种可能的替代解释，我们讨论了衰老的表现。与脱水生活相关的过程与能量消耗有关的观点一致，我们记录了在脱水生活期间储存细胞大小的减小，首次表明缓步动物在脱水生活过程中会消耗能量。
