Spot the flaw. Bluegill sunfish, a species of freshwater fish, prefer to feed in the open water in summer, but, in the presence of predators, they tend to hide in the weeds near shore. A study compared the growth rate of bluegills that fed in the open water with the growth rate of bluegills that fed only in nearshore vegetation. “Open-water” and “nearshore” fish were both measured in each of eight lakes, and the mean growth rate of open-water fish was compared to the mean growth rate of nearshore fish using a two-sample t-test. What was done wrong in this study?