Malnourished White Cloud Mountain Minnow

[briangriffin]

I have a White Cloud Mountain Minnow that looks malnourished. When we first introduced him to the tank he was very active. We then introduced some others to take the school size to 7 WCMMs. He seemed to be pushed out by the newer fish (swimming on his own) and now doesn't appear to be eating like the others do. At feeding times he is now typically swimming slowly around the bottom whilst the others are darting around picking at the food - typically flakes. Sometimes he rests on the gravel at the bottom of the tank before slowly swimming off. There is nothing visible wrong with him ie fungus or fin rot. He just looks malnourished. I'm thinking that he is stressed but really don't know what to do about it and getting him back to a healthy state. Any advice?