RICCI, C.; CAPRIOLI, M.; State Univ. , Milan; State Univ., Milan: Dormancy of Bdelloid Rotifers: costs and limits

Dormancy of bdelloid rotifers is commonly cued by water evaporation and is defined as anhydrobiosis. Costs and limits of anhydrobiosis were investigated and post-recovery life histories were recorded in bdelloid rotifers. Dormancy produced a sort of time shift of the age of the rotifer, that disregarded the time spent dry. The model proposed for this time suspension is the �Sleeping Beauty� as opposed to the �Portrait of Dorian Gray�, which predicts that the animal ages during dormancy. While duration of dormancy did not modify bdelloid life schedule, recovery rates decreased with increasing duration of dryness. Dormancy duration can be safely extended if the dry animals are stored under controlled conditions. Several factors affected bdelloid recovery after dormancy, including desiccation procedure, presence of substrates, and, unexpectedly, low food availability. Experimental results suggested that successful recovery from anhydrobiosis was not dependent on resources supplied to the bdelloids before desiccation. Factors other thanwater availability seemed also to induce dormancy in the bdelloids. Long-lasting starvation of newborns and reproductive bdelloids produced suspension of active life, which was resumed on addition of food. Several aspects of the observed inactivity strongly resembled the dormancy induced by the water loss.