Effect of juglone on the survival time of two Brachionus species (Rotifera): species-specific tolerance against oxidative stress

To investigate the effect of oxidative stress on the survival of two Brachionus species of rotifer, we examined the effective dose of juglone, which generates reactive oxygen species, and compared survival times between the two species. First, we observed that juglone affected survival in the rotifers in a dose-dependent manner between 0.02 to 20 μM, and that treatment at above 2 μM showed acute toxicity causing the animals to die within a few hours. Next, we found the difference in survival time between the two species exposed to 20 μM juglone: B. rotundiformis was significantly more tolerant against the substance than the allied species B. plicatilis. The findings suggest that exploring the basis of species-specific abilities to persist under oxidative stress will be of great interest to uncover the underlying mechanisms governing the stress resistance of the rotifer, as well as contributing to their stable mass production for aquaculture.