a breeder I know on a personal base had a huge Burundi frontosa by the name of Bob
Bob made it well beyond 25 years and if I remember it right even reached 30 years.....he passed away less than a year ago.
another place that might ring a bell is Verduijns' place. the importer, yup
they used to have a granulosus that arrived as the first fish that went into their 10.000L showtank and it passed away lasdt year. it's been in the store as long as it exists! that would make it well beyond 30 years, probably 35 years old and granulosus are caught as subadults.
myself I've bought a group of Mochokiella paynee in 1986. this is a tiny relative of Synodontis from Sieraa Leone.
and I bought them as subadult/half grown abnimals, at least 2 years old, given the growthrate of this species.
the last one's still kicking the bucket in a tank of a good friend......that tiny 2" fish is at least 24 years old and this is a fish that has a maximumsize of 7 cm or so.
some Synodontis nigriventris that I bought in 1984 at an age of 2-3 years (they grow as slow as petricola's) have been around until 2007, wich makes them reach some 26 years give or take a bit.
I've seen old substrate brooders, esp the larger ones from South and Central America, and frontosa's owned by people who claim their fish was 20-25 years old or more.
some fish do last, even small ones!
on the other hand, I've known plenty fish (catfishes too) that are really ancient and worn out at 5 or 6 years. some don't even last that long despite good care.
"And he piled upon the whale's white hump the sum of all the rage and hate felt by his whole race. If his chest had been a cannon, he would have shot his heart upon it"