Strategies to combat desiccation are critical for organisms living in arid and semi-arid areas. Larvae of the
Australian chironomid Paraborniella tonnoiri resist desiccation by reducing water loss. In contrast, larvae
of the African species Polypedilum vanderplanki can withstand almost complete dehydration, referred to
as anhydrobiosis. For successful anhydrobiosis, the dehydration rate of P. vanderplanki larvae has to be
controlled. Here, we desiccated larvae by exposing them to different drying regimes, each progressing
from high to low relative humidity, and examined survival after rehydration. In larvae of P. vanderplanki,
reactions following desiccation can be categorized as follows: (I) no recovery at all (direct death), (II)
dying by unrepairable damages after rehydration (delayed death), and (III) full recovery (successful
anhydrobiosis). Initial conditions of desiccation severely affected survival following rehydration, i.e. P.
vanderplanki preferred 100% relative humidity where body water content decreased slightly. In
subsequent conditions, unfavorable dehydration rate, such as more than 0.7 mg water lost per day,
resulted inmarkedly decreased survival rate of rehydrated larvae. Slow dehydration may be required for
the synthesis and distribution of essential molecules for anhydrobiosis. Larvae desiccated at or above
maximum tolerable rates sometimes showed temporary recovery but died soon after.
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