| Main Ref. | Mattos, J.L.O., W.J.E.M. Costa and A.C.A. Santos, 2015 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | none |
| Body shape lateral | fusiform / normal |
| Cross section | compressed |
| Dorsal head profile | more or less straight |
| Type of eyes | more or less normal |
| Type of mouth/snout | more or less normal |
| Position of mouth | sub-terminal/inferior |
| Type of scales | |
| Diagnosis |
Diagnosis: Geophagus diamantinensis is distinguished from all other species of the Geophagus brasiliensis species group by having the urohyal bone with a gentle anterior constriction (vs. strong constriction); presence of a small dark brow mark just posterior to pectoral fin (vs. absence); presence of a horizontal dark brown band on snout (vs. absence); and head more slender, head depth 77-86 % HL (vs. 87-122); G. diamantinensis is distinguished from G. itapicuruensis by having XIV spines on the dorsal-fin (vs. XIII), and from G. obscurus by having subterminal mouth (vs. terminal) (Ref. 118113). |
| Ease of Identification |
| Lateral Lines | 1 Interrupted: No |
| Scales on lateral line | |
| Pored lateral line scales | |
| Scales in lateral series | |
| Scale rows above lateral line | |
| Scale rows below lateral line | |
| Scales around caudal peduncle | |
| Barbels | |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total | 27 - 28 |
| Attributes | extending over most of the back length |
| Fins number | 1 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | 14 |
| Soft-rays total | 10 - 12 |
| Adipose fin | absent |
| Attributes | more or less truncate; more or less normal |
| Fins number | 1 |
| Spines total | 3 |
| Soft-rays total | 7 - 8 |
| Pectoral | Attributes more or less normal |
| Spines | |
| Soft-rays 14 - 14 | |
| Pelvics | Attributes more or less normal |
| Position thoracic behind origin of D1 | |
| Spines 1 | |
| Soft-rays 5 |