Water levels in the range 30-65 % initiate metabolic activities, eventually reducing the energy
contents down to levels insufficient to reach the state of emergence under optimal hatching
conditions. A depletion of the energy reserves is furthermore attained when the cysts
undergo subsequent dehydration/hydration cycles. Long-term storage of such material may
result in a substantial decrease of the hatching outcome. Cysts exposed for too long a period
to water levels exceeding 65 % will have completed their pre-emergence embryonic
development; subsequent dehydration of these cysts will in the worst case result in the killing
of the differentiated embryos.
Sufficiently dehydrated cysts only keep their viability when stored under vacuum or in
nitrogen; the presence of oxygen results in a substantial depletion of the hatching output
through the formation of highly detrimental free radicals. Even properly packed cysts should
be preferentially kept at low temperatures. However, when frozen, the cysts should be
acclimated for one week at room temperature before hatching.