Different Breeds Of Upside Down Catfish?

I've had an upside down catfish in my 20 gallon for at least 3 years. When I got him he was MAYBE an inch in size. Recently I had issues with him and moved him to my 55 gallon. But I'm confused, from my understanding upside down catfish are community fish? But he was picking on the two goldfish in the tank. So I tried to look him up again and he doesn't look like any pictures I've seen. He's almost solid black and about 4 inches long, while pictures have them more lacy or spotted colored. I'd have a picture but he's currently hiding under the filter fountains. And he's been doing better, and my 55 is semi-aggressive! Has a grown Convict, a Synodontis Ocellated catfish and 3 Jewel Cichilds in with him. In my 20 gallon he was always hiding in a log, but the in the 55 he's out and swimming around. Did he just want more room? Or is there multiple types of upside down and he's a semi-aggressive sort and not community? I originally had African cichlids in the 20 gallon tank, but they had a battle royale and randomly killed each other, after all being introduced at the same time. And growing up together. So my catfish was the only thing left in the tank. Maybe that's why he's aggressive? I'm just confused on what he is and why he's so mean.

 

If you can post a picture that might help with identification. But yes, there are many different species of Synodontis and they don't all play nice!

 

Sorry, it's hard to video a fish. I'm trying to upload another one I got after I actually managed to catch him

 

He's solid black and I didn't know he was a Synodontis at all! Had to move some things to catch him. So sorry if the water is a bit too stirred up....

 

Ok possibly not a Synodontis! How about Mystus leucophasis?

Giant Black Upside Down Asian Catfish, Mystus leucophasis, with care, maintenance requirements and breeding information for your tropical fish

 

OH WOW! Yea that's him! He has some small white dots on his side as described! "Not for beginners" Oh wow. I didn't realize he was supposed to be so sensitive, or that he was scaleless. I just thought I couldn't tell because he's black. That's why he's so happy in the 55 is that he's super active swimmer. I'm shocked though that I managed to get one. The site says he's rare. But the store I got him at continues to sell upside-downs, but they don't look like him. I picked him because he was different. That's awesome to know what he is! I feel bad I've kept him in a 20 gallon for so long. At least he's happy now. Thank you so much!

 

I'm excited for you! He must have got mixed up with the others somehow. Lucky find!