Is this fin rot?

What’s going on with this fish? Betta has had fin rot once before. But it was only on his pectoral fins..I didn’t notice this the day before, doesn’t mean it wasn’t there but I didn’t notice it as I was feeding him. He has a bad habit of sleeping behind the filter kind of on top of the heater once I installed that cut off filter as a flow guard on his filter but I don’t think it’s a burn cause of where it is.. Also anyone know what kind of betta this is classified as? I’m not too keen on them but I think they are done by tail types??
I have ghost shrimp in tank, can I treat by using a paragaurd dip for some time? Or does betta have to be quarantined?...

How big is the tank? Are you aware of the nitrogen cycle and did you cycle his tank before putting him in? What are the water parameters?

I would buy some aquarium salt and follow the directions on the back to find out how much you should add to the water. Remember to dissolve the salt before putting it into the tank though because it could burn his gills. I'm assuming the salt should be fine for the shrimp but I'm not sure so maybe someone else with more experience with shrimp can tell you more.

As for the tail type, he looks like a halfmoon betta to me, though it's kind of hard to see from the photos.

Problem should be resolved. Yes this is a several month old tank. I stayed up late after lights out. Betta was in his typical sleeping trance and as I shined my torchlight into the tank I watched a ghost shrimp swim off of him. They’ve been picking at his fins as he sleeps by climbing up the heater or prefilter sponge. Ghost shrimps have all been removed and are being used as treats for my cichlids. Some of them are large about inch half to 2 inches. But far as I can see they are legit ghost shrimp. Claw arms same size as legs and most have red tail dots or red bands on antenna. Was kind of shocked to find this. Would cherry shrimp do the same thing?