many Mochokids are in for the long haul.
I have Mochokiella (a tiny Mochokid resembling a fat mini syno) and 2 of the last 4 were also baught in the '80's; spring 1986
until a year or so, my mate had my last nigriventris. he kept that fish for more than 15 years, but before that time I had it.
it was the last survivor of a group I bought in may 1984 when I graduated and Marc and I went to Belgium on his old motorbike (a 1976 Honda 550 CB four)......the fish were transported home under my shirt
Verduijns even passed that with their famous granny.
that one died 2 years ago or so; but it had been imported as an adult Syno in 1973.....the first granulosus ever in the Netherlands and back then also the most expensive fish.
if your Syno was 2" or so, it would have been at least 1 year old, wich makes it at least 25 years old.
a respectable age for any hobby fish and also a prime example of a good cared for pet.
many Syno's can and do live for a long time.