Anhydrobiotic capabilities of bdelloid rotifers

To test if anhydrobiotic capability is apomorphic to class Bdelloidea, I focused on the recovery from desiccation of 15 bdelloid species. The species belonged to 6 genera, represented the four bdelloid families, and were collected from water and moss environments. Eggs or embryos, prereproductive and reproductive specimens of most species were desiccated and kept dry for 7 days. The highest recovery rates were obtained rehydrating adult bdelloids of moss species, while three aquatic species did not survive anhydrobiosis. Species from aquatic and moss habitats differed in their capacity to enter anhydrobiosis and to recover successfully. This difference may be related to the different desiccation frequencies of the two habitats, although aquatic species were able to survive desiccation. It seems likely that anhydrobiotic capacity is a feature common to all bdelloids, and that was subsequently lost by some species.