The signage you mentioned I believe actually referred to the invasive species plaguing Indonesian rivers (Those three are most well-known). They do have the pirarucu and gar, with other rosters the last time I visited are the wallagonia catfish, an sorubim, a couple of pacu,and several tilapias and red devil cichlids.
@Fargusno It's a nasty tank and the water was so dirty on my visit that there could have been a juvenile Loch Ness Monster and I still wouldn't have been able to see it!
