Training is going extremely well. Darwin is making quick progress (and he has the belly to show it). We’ve gone from swimming through a hoop to swimming through a short tunnel to swimming through a longer tunnel. It’s neat to see how both fish have their own personalities and temperaments. They are debunking the myth that a goldfish only has a 3 second memory!
Some notes: Both fish perform tricks swimming away from the light. Therefore I will need to work harder on shaping the behavior of swimming in both directions, or modify (soften) the light source. Also, in order to maintain the EO (desire to eat) I need to be mindful of maintaining the feeding/training schedule and avoiding too many trials in sessions. Otherwise the fish get full (satiate) and food is no longer valued as a reinforcer.