a cat shark, like most sharks, will eat pieces of shrimps, squid, octopus. If you prefer, you can also use ghost shrimps. As far as how to get your shark to eat, one thing you can try is put the pieces of food at the end of a stick or a piece of
tubing and wave it in front ot him/her.
I have 2 Epaulette sahrks and two rays and I got them to eat doing that.
Good luck,
Eddi