The alligator snapping turtles in captivity can be successfully kept on a variety of fish, beef and chicken products.
I feed mine a similar diet to the common snappers. It is good to give them whole frozen fish like smelts for example. A good addition
is raw beef liver and hearts. Some people feed their huge adult alligator snappers whole chickens, but this is of course for the
150 pound giants.
I also give mine live minnows and occationally gold fish. Also cray fish, and some snails which I leave in the tank to have the snapper
have one whenever they want.
Commercially made turtle sticks are also a good supplement, but way too expensive for the adults.