Fish and other aquatic organisms are exposed to many types of water pollutants, including metals such as aluminum. Although a low level of aluminum is found in unpolluted water, many lakes and streams have an increased level because of mining, sewage treatment, and accidental spills of toxic materials. Aluminum pollution can result in mass fish die-offs. In a laboratory, scientists exposed freshwater bony fish (Prochilodus lineatus) to water with a high level of aluminum and compared their blood osmolarity to that of fish exposed to water with a normal aluminum level (control). The results of the experiment are shown here (asterisks indicate P<0.05 between control and treated groups at a given time; BioSkills 3). Do the data support the hypothesis that aluminum interferes with osmoregulation in freshwater fishes? Explain.