I think stores like petsmart and petco are a hit or miss. I rarely go to those stores anymore but when I do, I only go to this one petsmart which is farthest away from me because the person their is considerably knowledgeable.
Well, if you see it again, take it out. Definitely don't tear apart you tank! Just keep an eye on your fish to make sure they don't start acting differently.
Its basically survival of the fittest. The weaker ones are not going to end up making it. I don't mean that one day you will just find him dead, the other fish are just doing what they would do in the wild. There is a reason do don't see fish with broken fins and a bent tail in a pond or lake...
It's probably a roundworm. They can be introduced on plants or fish. I'm not share what kind it is but if you see it again, you probably should remove it.
You could put some cherry shrimp, a few otocinclus catfish and a school of ember tetras in a planted tank. The largest ember tetras will grow is to about an inch.
What color is it? It could be a planarian if it has a triangle head. They can be incredibly dangerous to shrimp. If it's not a flatworm, it's definitely some kind of worm. If you see it again post a picture and I would take it out.
I dont think it is from the plants. His top fin seems to not have been cut because it looks quite natural and smooth. The only plant that maybe could cut him is the purple one at the bottom. This still does not seem likely because if the plant is on the bottom, wouldn't it cut his bottom fin...
It looks like green hair algae to me. It can form when you CO2 levels drop or they are not constant. If you don't have CO2 in you tank, the plant that you got probably had some on it and it grew from there. To get rid of it you can either pull it off or get some Amano shrimp, they usually do the...
The fry could be picking on that spot because it stands out on the fish. The fry also might be trying to kill him off because he is considered weak. I have a deformed white mountain minnow that gets chased around the tank every so often becuase there is something wrong with him. I would put them...