Any fish that are compatible with ACFs?

[mpmistr]

You could breed guppies if you really wanted to. You'd have to breed your own and be 100% you do not have sick fish, one parasite, bacterial infection, or virus and you could end up with a dead frog. It's actually more work than it seems and getting a sick fish is more common than you'd think.

Feeder fish in pet stores are riddled with disease, with your own fish, kept properly the risk is lower, but still exists.

If you are interested in feeding your frogs live foods I would go with nightcrawlers purchased from bait stores or insects such as captive bred crickets. I would avoid the common feeder insects like meal worms and super worms, since they have a rather hard to digest carapace.

As to your question about fish spines, fish don't have bones, it's cartilage and assuming the animal has no defensive spines like armored catfish have, it should be digested easily. I have fed my frogs fish before, though I've learned it's more trouble than its worth and they've never had any issue eating and digesting them.

[SwimminSteve]

I make no promises for this working for anyone else, but I have had some success with White Cloud Minnows. The key word here is some. About a year and a half ago I bought four little white cloud minnows. I realized later on as they matured that there were 3 males and 1 female, so I'm sure that stress contributed to their demise. After a couple months I was down to just one fish. I never saw the frogs stalk or even lunge at the fish so I assume that the fish simply died and then were eaten by the frogs. But after all this time I still have one minnow left! The frogs never bother him and he is very fast. I think that it works out because the frogs stay on the bottom and for the most part he only swims in the top half of the tank (40g breeder). The most interesting thing though, is that I never really feed the little guy. I feed the frogs HBH frog bites 2 times a week and I toss in a tiny pinch of dried bloodworms. The fish survives off of the bloodworms and the "dust" left by the HBH bites.

I chose these fish, because I read that they do well in room temperature water and they produce very little waste. I believe that they are a schooling fish, but I've never purchased more because I don't want to risk anything happening to the little guy I have left. They were around $2-3 each at my LFS, and I think it could be worth a try for you. However, they are a tiny and not-so impressive looking fish and you might be looking for something prettier. But, I'm telling you, the pretty ones must taste better....

Also, I'm not recommending it, but every once in a while I buy feeder guppies to give to my frogs. I trust my LFS as the fish always look healthy, but yes, I am taking a risk. I've had some of these frogs for over 7 years and feeding them guppies every 4-6 months or so has never done any harm. I do have to hand-feed the fish to them though, because they aren't coordinated/fast enough to catch them on their own in a large tank.
So I guess what I'm saying is, if you want to try it- try it. Just recognize that you are pretty much doing it for your benefit and not for the frogs'.

[mpmistr]

White Cloud Minnows are not a bad idea, they appreciate cool water like X. Laevis does. I'm not sure if they are 'top swimmers' but if they are, they would be advantageous to them because X. Laevis are mostly bottom dwellers. In a large enough system these fish may survive but like you said, it's only a matter of time. They have to rest or will just get careless and the frogs will clean house in due time.

I used to keep guppies and mollies with my frogs, they were all eaten. I think zebra danios may work well too because they are also top swimmers and pretty fast too. In a closed off system (as aquariums are) even in a very large tank, the advantage always goes to the predator.. so I wouldn't get attached to the fish and I wouldn't pay too much for them either.

If the fish are healthy and you have a bulletproof LFS or you breed your own and you're good at diagnosing fish illness and you quarantine you certainly could feed fish to clawed frogs. It's just that it's more work than it's worth and mistakes do happen. If you've had luck for 7 years feeding guppies I won't argue with that. There's always risks to live food but you can minimize it greatly by being smart.