Basket! My Tilapia Eaten My Oto Fish!! (Still Munching away now)

Wah lau...I see these Tilapia poops a lot hence purchased 6 sucker (Oto) fishes to clean up the tank...but guess who clean up who? Yes...that' my SGD$1.50 Oto fish in the mouth of the Tilapia fish!!! ARghhhh...