My fire eel fish tank

[leonmalay]

I so like fire eel fish.
Their colour is so beautiful.
But they are so choosy, only eat shrimp.
But I found online that they will eat other small fish also, why my fire eel just only eat shrimp but not small fish??
How to train them? Any one got experience?
Last time I ever just put small fish but no shrimp.... finally one of them was starving until died. So sad am I.