So back to the victim himself. The Anthias! Anthias die out of nowhere as do Copperband Butterfly fish. Having too much current in the tank is bad for these guys during feeding. The tank’s cuc makes a very quick meal of the victim and the hobbyist thinks the cat got him. Both types of fish (above) need to be fed twice a day at a minimum. If not they will die a slow death of starvation. We don’t realize it and then they’re missing. Just a possibility.