How do I get a skittish oscar to know that food comes at the surface of the water? I put some cherry shrimp in. I know he's had enough for today, but, he'll eventually need to learn to com up.

stop feeding for a day or TWO he will soon come and get it you will be amazed at a hungry O,s ability to get food ,their eyesight is amazing and they will DEFINATELY come up for it!!!!!!!!!!!!!!!

yeah, i agree with bgh. hungry oscar will come up
and grab anything that touch the water. the only
danger for doing this is the chance of oscar flight.
hungry oscar twill try to grab even flying insects
when hungry. in so doing, it may jump off the tank.
so keep lid over your tank to prevent such accident.

if your oscar i new to your tank just give him some time to figure out where the food is comming from and who brings it. in no time he will be swimming in front of the tank for food every time you walk by.