Enligt den här artikeln http://www.sage-hindawi.com/journals/ijeb/aip/360654/ finns det fem arter diskus:

In summary, we conclude that the genus Symphysodon is comprised of five ESUs (ESU = Evolutionärt signifikant enhet. Min kommentar):

· Symphysodon discus Heckel, 1840 (Heckel and abacaxi phenotypes – western Guyana
Shield – Negro and upper Uatuma, Nhamunda and Tombetas Rivers; western Brazilian
Shield – Abacaxis River and some other blackwater affluents of the Madeira River)
Synonym: Symphysodon discus willischwartzi Burgess, 1981

· Symphysodon tarzoo Lyons, 1959 (green phenotype – western Amazônia – river
drainages west of the Purus Arch)
Synonym: Symphysodon discus var. aequifasciatus Pellegrin, 1904 in part
Symphysodon Discus Tarzoo Lyons, 1959
Symphysodon aequifasciatus aequifasciatus Schultz, 1960
Symphysodon aequifasciatus haraldi Schultz, 1960? (in the unlikely assumption
that Schultz's account of the type locality – Benjamin Constant – is correct)
Symphysodon aequifasciatus in Bleher et al.

· Symphysodon aequifasciatus Pellegrin, 1904 (brown phenotype – eastern Amazônia –
lower reaches of Amazon River and affluents east of the confluence of the Negro and
Solimões Rivers)
Synonym: Symphysodon discus var. aequifasciatus Pellegrin, 1904 in part
Symphysodon aequifasciatus axelrodi Schultz, 1960? (if actual type locality is
lower Tapajós River )
Symphysodon haraldi in Bleher et al. in part

· Symphysodon sp. 1 (blue phenotype – central Amazônia – river drainage systems east of
the Purus Arch and west of the Negro and Solimões River confluence)
Synonym: Symphysodon haraldi in Bleher et al. in part
Symphysodon aequifasciatus in Ready and Kullander in part

· Symphysodon sp. 2 (the Xingú group – eastern Brazilian Shield – lower Tocantins and
Xingú Rivers)