That's what I thought as well. it was some sort of bad gene from breeding. It doesn't seem to effect it's swimming, I took the lid off and to check out the spine. Seemed a little off, but it's relatively uniform. The rest of the bettas were pink/colorless, so I chose this one & 2 others. I had a $3 off any purchase of $3 or more. I got 3 bettas for free. I need them to eat the bugs in the garden.