Aren't you worried about the eel and the Motoro?
Actually I was at first, but the motoro hasn't tried to eat him yet and right now the eel is longer than the motoro's disk is wide. I have just been feeding him so that he always has a lump on his back (he sure loves nightcrawlers...).
Also, I will probably pull the peacock eel later on to go in a different tank (maybe put a fire eel in this one).
Edit: Did you happen to notice the little bala shark in the one picture. He's about 1.5 inches and is the one out of a group of five the motoro didn't catch his first night in the tank. This one seems to be pretty smart and sleeps in the eel's cave.