It looks like mouthrot to me. Having worked at PetSmart for a long time and knowing the reputation of some of the locations, I am suspecting he arrived to the store with the beginnings of this condition.
If you haven't had him two weeks yet I would highly suggest returning him. If you have had him too long to do that there are other methods that can hope to heal it, but don't always work. But I'll get to that after a few questions:
1) Is your tank cycled?
2) Do you have a liquid test kit?
A) If so, what is the ammonia, nitrite and nitrate readings from said test?
B) If you have a dip test that is fine, but I will suggest getting the liquid kit. Its incredibly helpful.
3) When was your last water change?
C) How much water did you change?
Additionally, that bala shark will get far too large for you size tank and will do much better in a group. The algae eaters, they are the "chinese algae eater" will get big, mean and not eat algae.