Prey Size and Survivorship in Didinium nasutum (Ciliophora: Gymnostomatida)

The ability of the ciliate predator Didinium nasutum to survive and recover from a period of starvation is affected by the previous history of the predator. The size of D. nasutum increases with increasing prey size across a range of sizes of Paramecium species. This increase in the size of the predator when feeding on larger prey contributes to the survival ability of the predator under conditions of starvation. D. nasutum that had been conditioned to larger prey (and were themselves larger) were better able to recover from starvation than were predators that had been conditioned to small prey. D. nasutum conditioned to large prey may also be more likely to form resting cysts as a response to