I have 1 male betta, Rufus, in a 2L tank on my desk at work, I noticed yesterday that he seems to have a bump or growth on his back that wasn't there on Friday.
At first I thought it was some fish food flakes stuck to him, but it hasn't come loose today...
He's been very lethargic since last Thursday, and the last two days all he has done is swim at the top of his tank, staring into a corner.
He's been in this tank for about 3 weeks, I do 50% water changes every 2-4 days. Water is pH neutral today.
No live plants, just gravel and a castle. No filter, lighting is only the office fluorescent lights.
I feed Rufus 5 TopFin Color Enhancing Betta Bits every evening, but gave him some flake food on Friday... which he didn't eat at all.
Please excuse the blurry quality of the photo... I only have my blackberry with me to take pictures. The bump is the lighter coloured part on his back.
Has anyone seen anything like this before?