A couple months ago I introduced a ~3 inch green sunfish that I caught hook and line into an aquarium containing a ~9 inch bullhead. Instantly, the bullhead came out and attacked the green sunfish. The sunfish had a pretty nasty wound on it's tail, and I thought for sure it wasn't going to survive. However the next day it fed on an earthworm, and within a week it was swimming toward the front of the aquarium, begging for food. This went on until about two weeks ago, when the green sunfish refused to take an earthworm, and ever since then it will only take pelleted food, and not very aggressively either. I don't this this is due to stress, as surely there would have been more stress after the green was introduced, and he fed vigorously then. Also he has turned much darker, and I thought fish turned lighter as a response to stress. What does anybody out there make of the situation
