Franklin is freaking crazy. He's becoming my favorite. He swims so fast, and he's all over the place! He also spends a lot of time cleaning up the bottom of the tank, and he doesn't give a damn about the others. Since the other fish don't eat much (or at all), Franklin is quite well fed. Getting a bottom feeder was a good idea.
Schuylkill is kind of a jerk. He likes to chase the other fish. I think he's just playing, though. Emilio is a little follower; he'll chase after the other fish, but he backs off as soon as they face him. Murphy strikes me as the cool guy. He's kind of a loner, but he'll school and eat with the others. He and Schuylkill seem to be buddies.