Upside Down Catfish identification help (Featherfin?)

About 8 months ago we bought a common upside down catfish from the local pet store. The tag on the tank said it would grow to be maybe 4-5". Now, 8 months later, he is about 4". I've been doing a bit of research and from what I've found, it seems as though we were sold a Featherfin by mistake. I would like a second opinion though. It doesn't look like he's slowing down with growing. I've attached some pictures of him. The first picture is when we first got him vs him 2 months ago (in comparison to his pirate ship.) Any help identifying the breed would be greatly appreciated.

 

I'd say you're right & it's a Synodontis Eupterus, featherfin catfish.

 

Definitely eupterus. No other Syno has a dorsal fin that tall.

 

Definitely a featherfin. He's beautiful!

 

Wonderful! Thank you, guys! I love this monster. I will get a bigger tank asap =)