Help needed to identify a changing catfish

[LuluH]

Hello ! I bought this little fella or lady 6 months ago and it was 2 inches long , I have a 220litre tank so room to grow. It hid for many months,.. it was black and white/nude coloured brain lobe patterning that attracted me .. however... I love it but its changed to a dark and mid brown ( see photos ) with circle markings, less brain/zebra Camo - and 5 times bigger - he has always had a tall fin on his back , almost the same as his length proportionally and I cant see on with these proportions online. please advise ? He's very engaging now.. growing fast, and likes hanging with my upside down catfish who are half his size. sometimes also swimming upside down ... thank you

 

[Wills]

Hi that’s a synodontis eupterus or feather fin squeaker. The pattern it had when smaller is it’s baby pattern which it grows out of into this pattern with spots. Looks like it’s getting started but the feathers on it’s dorsal fin get really long and they will spend a lot of time swimming upside down which is it’s natural behaviour. Very cool and under rated fish I had one a long time ago and still think about them if I ever get a big tank again these would be high up my list.