If he's anything like a wels he will be pretty shy. After a while getting used to new tank my wels would start coming out more but they were never very active during the day, they liked to hide then come out when it was dark, when they would be swimming all over the place. If the hiding places were good enough though during the day you would have never even known there was a catfish in the tank at all. I had one that hid somewhere I could not figure out for weeks then finally realised she/he had found out how to get underneath one of the big log cave decorations in there and she/he had been hiding under it the whole time. To this day I'm not sure how they managed it, there was only a thin layer of pebble substrate under it too and they continued to do this till they were over 8 inches long and it was only a 55 gallon tank.
Nice pic!