It just takes time with oscars. They are notorious for pouting and sulking when they're moved or disturbed. Wilds can be even worse, depending on how long they've been in captivity. He may still be adjusting to seeing a human being every day.
I would just give him some time. Keep his temp in the mid 80s, continue to do regular weekly water changes on his tank, and if you want to add tankmates, find something that doesn't grow too large but stays active. I like deep-bodied tetras like Congo or Buenos Aires tetras. He may or may not chase/kill/eat them -- that usually boils down to the temperament of your individual oscar.
I would just give him some time. Keep his temp in the mid 80s, continue to do regular weekly water changes on his tank, and if you want to add tankmates, find something that doesn't grow too large but stays active. I like deep-bodied tetras like Congo or Buenos Aires tetras. He may or may not chase/kill/eat them -- that usually boils down to the temperament of your individual oscar.
