Rainbow fish

[Scotty-D420]

I have a young australian rainbow fish that is very pale looking and is shaking its tail all of the time(much more and harder than normal). It looks stressed. the other two rainbows look good and colorful. Has anybody ever had one of their rainbows act funny like this? water perameters are good and all other fish are acting normal and healthy.

[Lady Hobbs]

Haven't seen any of my bows act like that. Wonder if it would be his way to attract a female or showing dominance but all mine do is chase each other.

[Jacko]

Is there anything else visible on him? He could have something like a fish louse near the base of his tail... Is he super skinny or is it just his coloring and activity that seems off? I have 3 australian rainbows and never see this activity. The only rainbow I see shaking out of is my male gertrude when he's trying to show off to the female.

[Scotty-D420]

it has one scale that isnt flat with its body in the center of its body at the bottom. It is a little bit skinnyer than the others but not by much (just not as full body). No its not displaying, it usually is trying to avoid the others. I cannot determine the sex but i think it is a female.
I got this one and another that has red fins and is just now starting to really develope its colors i think it is a male at the same time and they look the same age.(this one has yellowish fins). And the other one i got about a month after and it is a lot more mature and more vibrant coloring.(just some extra info for anyone who has ideas)

[Lady Hobbs]

I hope this is not the beginning of dropsy. That will cause scales to raise. Try an anti-parasite medication.