looks like
this one changes color when maturing; young ones are gleaming (hence the name) and with a white belly; older ones tend to become less shiny, but they usually keep the white belly.
I've seen em in the past (15-20 years ago African riverines were much more popular) and they come in a range of colors; coppery or golden, silvery (hence aluminium catfish), light brown, grey, dark.
there's one of these residing in a shop less than 1 mile from me for over a year.
they had 2, managed to loose one and the leftover is still there in a small tank full of Malawi and Syno hybrids
sad story
yours looks huge!
the eyes are a bit cloudy. he used to have this?
8 years is a respectable age, this is not a commonly kept fish,
African riverine non Syno cats are usually left out in the dust.
no idea how long they last, but obviously this Chrysichthys species can last for quite some time
was it tiny when you bought it or already sizeable?