This fish is most likely the spotted pike characin, Boulengerella lateristriga. They are not bred in captivity, so your specimen is wild caught, and wild caught fish can sometimes be difficult to get to eat in captivity. What are you attempting to feed him? They should eat live foods readily and can be converted to frozen smelt or other fish with a little work.
Not very much info in post, so hard to say what is causing your fish to not eat. What is size of tank? Water parameters?
2 days is not all that long, fish can go weeks without eating. I would give the new fish a week to settle in before becoming too concerned. Garlic can also stimulate a fish's appetite. If it has been more than a week in the tank and the fish seems comfortable but will not touch food- then I would become a bit concerned. Right now, I think it is still a bit soon.
