Good questions IMHO. Catfish also feel even the slightest vibrations in the ground and water of anybody or anything approaching them.my biggest question is their vision......during the day. They have those large eyes, but is that just so they can see better at night and the pupils can absorb more light? They really don't seem to hunt by sight, but at the same time they sure do spook easily. Anyone else ever wonder about this?
I think it's a fair question considering most - or at least ALOT of catfish have tiny eyes and very poor vision.....and at that same time while some seem to be "Swimming Noses" with a sense of smell and taste that rivals a Shark I noticed some cats will go right past food and ignore it, or don't realize it's food - even with a food item that is part of their captive diet.
When cats lose both eyes, most of them, like Pims, even free-swimmers like Pangasiidae, still fend for themselves fine.
When a catfish goes by food and remains unattracted, I think it is either not hungry or its mouth is full at the moment or the wildly swirling tastes in the tank water have it confused where the food actually is.
Cats and fish in general sense electricity in the water too with their lateral line and sensing areas. Including electromagnetic field. This is supposedly in part how fish know where to go, migrate to - by sensing the Earth's electromagnetic field.
This may help too: