hi, guys
Anyone has a suggestion on how to trap this fellow? It's killing my bottom dwellers. It has already killed my royal gramma, yellow watchman et al.
Need urgent help. Tried to trap it with a bottle with inverted top.... no luck... it's too smart to fall for it. The trap has trapped and killed my cleaner shrimp

.
Would prefer not to go for overhaul or drain water to get this "devil".
Any advice would be very much appreciated.