| Main Ref. | Arcila, D., R.P. Vari and N.A. Menezes, 2013 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks | Mature males with hooks on anal-, pelvic-, and caudal-fin rays (vs. absent in mature females). |
| Striking features | |
| Body shape lateral (shape guide) | fusiform / normal |
| Cross section | |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | terminal |
| Type of scales | cycloid scales |
| Diagnosis |
Acrobrycon ortii is distinguished from A. ipanquianus by having the following characters: 19-21 anal-fin rays (vs. 23-27); body depth at the dorsal-fin origin 22.8-37.4% of SL (vs. 49.0-51.2% SL); and the caudal peduncle length relative to the body depth at the dorsal-fin origin 160-230% (vs. 240-440%). It can be diagnosed from A. starnesi in having 19-21 branched anal-fin rays (vs. 22-26), 53-58 perforated lateral-line scales (vs. 61-66), 19-20 horizontal scales rows around the caudal peduncle (vs. 22-26), body depth at the dorsal-fin origin relative to the least interorbital width 90-120% (vs. 70-80%), body depth at the dorsal-fin origin relative to the anal-fin base length 70-90% (vs. 100-120%), and the horizontal eye diameter relative to the least interorbital width 90-110% (vs. 70-80%) (Ref. 94771). Description: dorsal-fin rays ii, 8; anal-fin rays ii or iv, 19-21; pectoral-fin rays i-ii, 9-11; pelvic-fin rays ii, 6 (Ref. 94771). |
| Ease of Identification |
| Lateral Lines | Interrupted: No |
| Scales on lateral line | 53 - 58 |
| Pored lateral line scales | |
| Scales in lateral series | |
| Scale rows above lateral line | |
| Scale rows below lateral line | |
| Scales around caudal peduncle | 19 - 20 |
| Barbels | |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | no striking attributes |
| Fins number | 1 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | 10 - 10 |
| Adipose fin | present |
| Attributes | forked |
| Fins number | |
| Spines total | |
| Soft-rays total |
| Pectoral | Attributes more or less normal |
| Spines | |
| Soft-rays | |
| Pelvics | Attributes more or less normal |
| Position abdominal before origin of D1 | |
| Spines | |
| Soft-rays 8 - 8 |