| Main Ref. | Malabarba, L.R. and J.K.F. Mahler Jr., 1998 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | |
| Body shape lateral | |
| Cross section | |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Diagnosis |
Large mouth gape (mouth width 21.5-27.1% SL) and squarish instead of conical head shape in large specimens. Shorter dorsal-fin spine (10.2-13.4% SL, vs. 13.4-21.0 in M. cottoides, 12.7-17.8 in M. parahybae, and 10.2-17.5 in M. cibelae) and larger predorsal length (40.4-45.7% SL, versus 35.1-42.0 in M. cottoides, 33.8-41.0 in M. parahybae, and 33.1-38.6 in M. cibelae) also distinguish this species. |
| Ease of Identification |
| Lateral Lines | Interrupted: No |
| Scales on lateral line | |
| Pored lateral line scales | 6 - 9 |
| 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 | 6 - 7 |
| on upper limb | 2 - 3 |
| total | 8 - 10 |
| Vertebrae | |
| preanal | |
| total | 29 - 30 |
| Attributes | |
| Fins number | 1 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | 1 - 1 |
| Soft-rays total | 6 - 6 |
| Adipose fin | present |
| Attributes | more or less truncate; more or less normal |
| Fins number | |
| Spines total | |
| Soft-rays total | 9 - 12 |
| Pectoral | Attributes |
| Spines 1 | |
| Soft-rays 5 - 6 | |
| Pelvics | Attributes |
| Position | |
| Spines | |
| Soft-rays 6 - 6 |