Backyard Aquaponics
A place to discuss aquaponics

Apparently channel catfish marble crayfish and Tilapia all thrive in water about 29.5C 85F. I wanted to know would the Tilapia eat th crayfish(I'v heard there herbivores but some say they eat meat to) and will the catfish eat the Tilapia (they should bes bottom feeders but would they take live meat if they can catch one)

obviously the catfish will try to eat a crawdad, so maybe some sort of “crab Pot” would be in order?

Young (small) tilapia tend to have a really strong protein hunger and will try to eat other fish that are smaller than them (as in two week old fry will happily try to eat 4 day old fry for instance.) Now adult tilapia are not really predators though they can be rather aggressive about breeding and a female tilapia getting ready to release a mouthful of fry can and will do damage to tank mates that don't give her privacy.

Will Catfish eat tilapia. Perhaps but I've not actually seen it happen. I have in my sump tank 3 very large Channel catfish (over 4 lb each) and there are perhaps a dozen small tilapia that escaped the cage when they were fry. The tilapia are between 2 and 4 inches. The catfish seem too well fed to try very hard to eat the small tilapia. I do know that in some parts of the midwest, people stock tilapia in their farm ponds to be food for the catfish and bass when the cool water in the fall makes the tilapia too sluggish to escape. The tilapia won't survive the cold there in the winter.

My My recommendation if you want to keep tilapia in the system, make a cage for them. That way you don't have to worry about uncontrolled breeding of the tilapia in the warm weather. If tilapia get started breeding, they don't grow out very fast. This is why most tilapia farmers raise all male stock. Well that and the males grow even faster than the females.

Any cat is generally a scavenger, it will take weak fish for sure. Often they're nocturnal, so they could surprise a sleeping fish. They will eat crayfish.
You will just have to watch the sizes, make sure they are all around the same and they wont eat each other.
Crayfish are also scavengers, preferring veggies quite often. They will take weak or dead fish, but will generally not bother sleeping fish. Keeping them for attacking each other is more of a challenge.

As for your specific breeds, I don't know anything, I base my assumptions above on yabbies, tandanus, salmon cats and barramundi.