I took a good look at the gulpers and it looks like they have grown 1/2 inch. They had not eaten any meal worms since day one. One has become my favorite, it's darker than the others and is always cruising. I snapped a couple of meal worms and it came by and finally took them. It also tried my fingers.
Today I bought 30 baby guppies and 20 ghost shrimp and added them to the tank. The gulpers couldn't catch the shrimp but they definitely preyed on the weak and dying guppies.
Is it just me or do other gulper keepers think these fish act like sharks? I know catfish fish will search in all directions and lock on prey and grab. The gulpers seem slightly different more like a great white. The gulpers circle and turn their mouths at an angle downward or upward and open and bite.
Of course they speed up doing this but they also grab food and turn the mouth so that the food will be at the corner of the mouth. They hold it in the corner of the mouth bite twice then move the food closer to the center then engulf. The gulpers also mouth bite a few times, to taste the object, then decide whether this is suitable. Like a great white biting someone to see what they are.