My problem betta is back at it again!!! He always manages to get sick or injured some how. He was completely fine this morning, but after I came home from work, I discovered that he has a huge white hole in the center of his forehead. The crowntail that shares his divided 10 gal is fine. Is it an injury or some sort of fungus? I do switch him and the crowntail to different sides of the divider ever few months to give them something new to explore, and I just switched them yesterday. I'll post picture of his injury here; thank you!