Oh, okay. Horizontal lines are stress stripes so maybe he was upset about something. Some fish get stress stripes very easily. One of my girls get stress stripes for every meal. As long as he's acting healthy, don't worry about it. :)
It's weird, some males will get breeding bars. Some males have eggspots too, that only females are supposed to have. Confused little guys. :) Are the bars on your male horizontal, running from his head to tail, or going up and down?
Hi Bluebell, thanks for all the sweet comments about my betta babies. In answer to your one question, breeding stripes are pale vertical bars that show up on dark colored female bettas, kind of like reverse zebra stripes. It's one of the ways a female shows that she might be interested in breeding with a male.