The catfish looks like one of the spotted Pimelodus species. The dark one above it is an Altolamprologus cichlid from Lake Tanganika, either A. compressiceps or A. calvus, both have various colour morphs around the Lake. I think the only difference between them is the pattern of scales on their heads, so it is very difficult to tell them apart.
All the tanks in this public aquarium are like pretty decorations set up by someone who doesn't know anything about fish. More than the randomly-mixed fish species, the "barnacle-covered roots" used in a freshwater tank is really bugging me!
@Chlidonias A lot of their fish are rescues, so I think part of it might be they design the tanks not knowing what they'll be getting, beyond salt/fresh. No idea if that's the case with this tank.
