Actually, 'Geophagus' itapicuruensis is one of the closely related, brasiliensis complex species. I've never seen them in person, but from what I understand they are insanely difficult to tell apart other than the much smaller adult size.
essy - Since they are so hard to tell apart, is it the red in the dorsal fin that alerted you (similiar to the red bahias) or was it the curved blue irridence lines? Not doubting you, just want to know what to look for so can seperate brasiliensis/red bahia/itapicuruensis in the furture.