blister

I woke this morning to see a white bubble/blister had appeared between the dorsal fin and body of my catfish. Not sure how long it's been there or if it's just appeared. I generally check the tank everyday just to do a head count and make sure there is nothing wrong but the catfish is generally...

I've just come home from work and have noticed that one of my black widow tetras has got a blister like lump on its mouth. I can't really find anything online to help. I changed their water a couple of days ago so levels are normal. I haven't noticed it before so either it's been there a while...

my betta, bulma, has seemingly overnight grown an oval lump on his side.hes for the most part active and eating well. it’s on his abdomen towards the back and is only accentuated on his right side. i’m really worried about him so if anybody could help me figure out what is wrong and how to treat...