Answer:
The upper graph shows stagnation at the ~12-14 day mark, whereas the lower graph exhibits decreased growth at that same point.
Step-by-step explanation:
In the upper graph, the growth of P. Aurelia plateaus and remains relatively constant, as evidenced by the lack of changing volume. This occurs regardless of the setting (separate/mixed growth). When grown in a mixed population, the carrying capacity of P. Aurelia lowers, as it must compete with P. Caudatum.
In the lower graph, the growth of P. Caudatum eventually stagnates when grown in separately, but decreases when grown with P. Aurelia. This indicates competition among the two species (P. Aurelia being the better competitor).