Nipping Or Fin Rot?

Hello everyone! My molly's tail was completely normal yesterday and today I came home to most of her tail fin gone Does this look like fin rot or nipping?
Thanks!

 

Definitely fin nipping. Do you have any males in the tank?

 

Is she pregnant? That looks more like she caught it in something. Clean water and aquarium salt will heal it. Look around to see where she could have caught it. Are any larger fish in the tank?

 

Definitely fin nipping. Do you have any males in the tank?

The molly under her is her brother and there's a guppy pair with young fry as well. I'm not sure on the sex of my four neon tetras

 

Looks like it was bitten. Probably from her brother.

 

Is she pregnant? That looks more like she caught it in something. Clean water and aquarium salt will heal it. Look around to see where she could have caught it. Are any larger fish in the tank?

Possibly/ more than likely pregnant but I'm not good at telling with the mollies.. they're balloon x sailfin babies so they're always super fat lol. Her brother in the pic is the biggest fish in the tank. Thanks!

 

My striped Raphael catfish has had its tail like this for quite a while. I originally suspected it to be fin rot and I’ve treated the tank twice now but it seems to stay the same. I have a rainbow shark in the tank as well. They tend have some territory disputes, not many that I ever see, and when I do see it’s usually just 1 fish running from the other for a second and that’s it. I’m not sure if it’s constant daily nips and quarrels or some kind of bacteria. What do you think from the pics? They aren’t great but it’s the best I can do haha thanks for the help

 

My striped Raphael catfish has had its tail like this for quite a while. I originally suspected it to be fin rot and I’ve treated the tank twice now but it seems to stay the same. I have a rainbow shark in the tank as well. They tend have some territory disputes, not many that I ever see, and when I do see it’s usually just 1 fish running from the other for a second and that’s it. I’m not sure if it’s constant daily nips and quarrels or some kind of bacteria. What do you think from the pics? They aren’t great but it’s the best I can do haha thanks for the help

Looks to me like nips. I would isolate this fish and treat them.