I'm sure one of our pacu wishes he was the only pacu in the tank, as his brother is quite the bully. When Leonardo gets in his rambunctious mood, he goes after Adonis and tries to ram him with an open mouth. He chases the other pacu back and forth, creating tsunami waves in the tank. The overflow box goes slosh, slosh, slosh as the tidal waves hit it. Leo is usually the rowdiest after eating. In the small overcrowded 55 gallon tank, he would try to herd the other pacu and the four oscars into one corner of the tank and keep them there while he had the rest of the tank to himself. In the big tank, he only "herds" his brother Adonis and leaves the two oscars alone. I think our Leonardo would have made a great sheep dog! Leonardo has personality plus, and wants all the attention for himself. (He wants all the food too) He's the tank bully, but not in a malicious way. He's most exuberant when he greets us. His brother has a rather dull personality in comparison.