They are very similar as juveniles, a side shot of the fish might help a little but just the shape of the head has me guessing Juruense but just guessing. Probably the best way to tell the species is how much you paid for it as a tigrinus usually costs 4 times more than a juruense. If the fish is stressed, you might try turning off the bright aquarium lights, at least during the night if not most of the time, provide some shade for the fish, like driftwood, if you need lights for plants. Hopefully the fish is eating well, sometimes they won't eat anything but live foods at first and feed better in darkness..
I didn't buy this fish. This was the photos the guy posted up about his fish. He was selling it as a Tig, and I wanted to be 100% sure before I paid Tig money for a Jurnese. Thanks guys!!!