Factors affecting long-term survival of dry bdelloid rotifers: A preliminary study

Abstract

Naturally dried lichens and mushrooms were collected, stored at various relative humidities and temperatures either under air or argon, and extracted in a 0.2 M sucrose solution to determine the long-term survival of resident bdelloid rotifers. Survivorship of rotifers in samples kept at 21 °C for 8 months declined at both <1% and 76% humidities, but remained the same as the starting levels at 23% and 43% humidities. Lowering the temperature to 4 °C improved survival at both <1% and 76% humidities; at -20 °C and <1% humidity, survivorship of rotifers did not decline for up to 18 months. Storage at 21 °C under argon gas improved survival of bdelloids at <1% humidity, but not at 76% humidity. These results suggest that several processes, including oxidation reactions, may be partly responsible for death of anhydrobiotic bdelloids. To facilitate taxonomic work it is recommended that naturally dried samples containing bdelloids be stored over a desiccant at temperatures below 0 °C until they are to be rehydrated.