Interesting, seems the fish we know as P. friedrichsthalii, may have actually had some confusion around it's description and thus the fish we have should actually be P. multifasciatus, not sure if I've seen P. loisellei around in Aus, but apparently that is the true P. friedrichsthalii.
Nomenclature changes in two Central American cichlids
By Juan Miguel Artigas Azas
A new paper by Rico Morgenstern brings to light facts that force important nomenclature changes for two well-known Central American cichlid species: Parachromis friedrichsthalii and P. loisellei. The paper details the circumstances and presents an examination of the fish collections made by Emanuel Ritter von Friedrichsthal in Central America between 1838 and 1841. The most important results establish that the fish we now know as Parachromis loisellei was in fact previously described as P. friedrichsthalii, a name we should now use when referring to this species. The fish hitherto known as Parachromis friedrichsthalii should now be called P. multifasciatus. The name Parachromis loisellei falls now in junior synonymy with P. friedrichsthalii. These changes may create confusion but get use closer to have a sounder picture of Central American cichlids taxonomy.
Morgenstern, Rico. 2018. "Fishes collected by Emanuel Ritter von Friedrichsthal in Central America between 1838–1841". Vertebrate Zoology. v. 68(n. 3), pp. 253–267 (crc09154) (abstract)
I understand that this might be old news for some, but was news to me, so thought I'd share. haha