Why is my glofish tetra being attacked by another?

[AmberAmbie]

So recently I had gotten glofish tetras and I originally had 4 but then past weekend I got 2 more one of which is a dark pink. And this morning I had noticed that it had half its tail nipped off I know tetras are clam fish so is it a concern that it was attacked by another? And then I have another one which is of a yellowish orange and seems to have a more round of a belly than the others is that also a concern?

 

[JuiceBox52]

Skirt tetras are known to be nippy amongst themselves and other fish. This is less common in larger groups so if the space allows I reccomend getting 2 or 3 more.

Keep an eye on the rounder one, it may just be a female, but it could be bloated or have dropsy. Do its scales stick out like a pinecone when viewed from either beside or above?

 

[Retired Viking]

Black skirt tetras are fin nippers for sure, that is why I avoid having them, with the glofish tetras you can not go by color but by shape to try and determine what type they are.