Did something attack my neon tetra?

So I go to feed my 10 gallon tank and I noticed one of the neons had a crooked/broken tail and another it’s red was a little faded at the tip of the tail. Did something try to eat my neons? They are a bit nippy with each other and the only other thing in there with them is a single platy a mystery snail and a couple julii cories I got last week but they are still small. Also one of the cories tail looks a little round out it doesn’t look like the rest of them. Sorry for the pics the tank is a little dirty with algae on the glass can’t seem to get rid of it. The colors on the rest of the neons don’t look faded or anything they are eating fine and swimming normal.





The one on the top left is the one that the end of its tail is kind of faded.



It was hard to get a picture but the Cory in the back you can kind of see his tail is kind of rounded.




This is another one just for comparison.

 

What type of filter do you have? Any decor it could've got stuck in? Doesn't really look like something caused by a fish attack to me; I feel like the fins would be torn up as well.

 

What type of filter do you have? Any decor it could've got stuck in? Doesn't really look like something caused by a fish attack to me; I feel like the fins would be torn up as well.

I have one of the hygger (i think that’s how you spell it) sponge filter. The one that has the dual sponges. As for the decor it’s just plants and a pc of unknown driftwood and mopani wood that’s always been in the tank with them and some river rocks.

 

Hmm. I'm not entirely sure of the cause then. I've heard of a disease (can't remember the name) that can cause a neon's spine to become crooked. I believe it is contagious and the infected fish will usually die, in which case it's best to separate them to try to prevent the spread. Perhaps another member can step in? This seems a bit out of my knowledge range.

 

Hmm. I'm not entirely sure of the cause then. I've heard of a disease (can't remember the name) that can cause a neon's spine to become crooked. I believe it is contagious and the infected fish will usually die, in which case it's best to separate them to try to prevent the spread. Perhaps another member can step in? This seems a bit out of my knowledge range.

I’ve heard of something like that too but on mine it looks like the bone is sticking out.