Bowie is missing the bottom half of one of his pelvic fins and I am convinced that he bit it off out of frustration/boredom during my vacation a couple weeks ago (I was out of town for 3 days, and he's never been left alone longer than a workday before.)

Changing the tank decor/rearranging, providing new toys on occasion, and most importantly interacting with them regularly can help soothe their restless nature and keep them from tail-biting. I change things around a little in his tank once a week (he is the most high-maintenance as far as entertainment is concerned) and spend at least 15-20 minutes a day with him, for a few minutes in the morning, a few minutes when I get home from work, and a few minutes before bed. Tail biting is supposedly a very rare habit in bettas but I think it's more common than most people think in "depressed"/lonely/bored fish. They're so emo.
