Betta Tail?

Hello!

I recently got my first Betta "Joffrey" (about 2 weeks ago). I thought he looked quite normal for the first week until yesterday, when I noticed half his tail was gone. I'm pretty sure he has fin rot so I am treating him in a quarantine tank with aquarium salt. Hopefully things get better...

Anyways, this isn't exactly a thread for a sick fish, since my question is regarding his tail! Looking at pics of his tail before it receded has had me thinking: I've never seen a veiltail like this before. It's like split in two. I thought it was normal until I actually realized I couldn't find photos of similar tails. So I'm wondering if this could have been fin rot all along? Might his tail have been full and started to part like that before I even got him? I'm asking because it seemed so healthy compared to what it looks like now (he also has damaged scales on his back which are looking better with the salt treatment). And how can it have grown (since the part is gone), and receded at the same time...? I thought fins/tails grew from the ends, not from the body (?)

When I first got him:





and now, the tail seems to have grown and receded at the same time...:




What do you think?

Thank you for your help!

 

I'm so sorry, I don't see where to edit my post, but it looks like my s are not showing up. Here they are again.

 

The s show up on the app just not desktop version of the site. They're working on that bug now.

It looks like his tail was ripped originally, not sure if it was officially fin rot then but definitely would open the door for it to develop.

 

Thanks for your answer! That makes sense.

Also, does it look like fin rot on the last 2 pictures or regrowth? I know regrowth is supposed to be translucent, but that fin rot can also be white...
His pectoral fins have what looks a lot like growth since the ends are longer and translucent (I think it is noticeable on the pictures). Would that be a good sign towards fin rot recovery?

 

To me he is looking good, keep up the good work!