Now that Mango Smoothie understands the basic structure of training, I have begun teaching her to swim through a hoop.
I placed the hoop (on a weighted stand) into Mango's tank for the first time today. As I put my hand with the hoop into the tank, Mango swam through the hoop to nibble on my hand. Guess this trick isn't going to take much work! I didn't reinforce (reward) the hoop swimming this time. I want each of my fish to wait at least briefly in his/her check-in zone (where I have taught them to Stay) before proceeding to perform a trick. Just about every trick I teach will thus be part of a short chain: check in -> wait for a cue -> then go do the requested behavior. Today's session was aimed at teaching Mango to wait at the check-in area (at the front of the tank, looking at me and the cue lights) in spite of the presence of an interesting, novel prop. She checked in beautifully, ignoring the hoop. In the next session I'll repeat that a few times and then begin working on a reliable hoop swim. I expect Mango will speedily perfect the hoop trick.