Weird swimming and marks

[Zack333]

I recently received some juvi African peacocks and started quarantine (water quality is good) with melafix 3 days ago and just noticed this guy he's swimming odd as in he looks weak and he has odd marks beginning on the ends of his fins. They seem to make his fins almost transparent. Anyone know what's wrong?
Thanks

 

[Zack333]

Here's an image

 

[Deadliestviper7]

Here's an image

View attachment 1331804

Fin rot?

 

[Zack333]

That's what I was thinking I just figured three days with melafix he would not develope fin rot but I guess so. I'll continue dosing melafix. Also here's a better pic that also shows how he is kinda acting swimming and floundering some

 

[Zack333]

Thanks for the advice, unfortunately he just had a mini seizure and passed away. All the other fish look good and don't show the same signs so hopefully it was just him and it didn't spread
Thanks for all your help