My betta lives with Emerald eye rasboras, some otos and a woodcat. There were 5 amano shrimp in there, but he ate them all. The last one lived in the filter for many months. When I would rinse the filter media, he would swim out, then go back in right away. This week the Betta got him first. I found his little tail shell lying on an Anubias leaf that evening. Bad Betta!