| Main Ref. | Whitehead, P.J.P., 1985 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | no special organs |
| Different appearance | males alike females |
| Different colors | males alike females |
| 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 | superior |
| Type of scales | cycloid scales |
| Diagnosis |
Belly sharply keeled. Flanks silvery without a distinct silver stripe (cf. Platanichthys). Distinguished from R. melanostoma of freshwaters by having more dorsal and pectoral fin rays and total gill rakers; from small Sardinella and Harengula by the evenly rounded hind margin of the gill opening; and from Sprattus fuegensis by having i 6 pelvic fin rays. |
| Ease of Identification |
| Lateral Lines | 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 | 0 |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | 41 - 45 |
| Vertebrae | |
| preanal | |
| total |
| Attributes | no striking attributes |
| Fins number | 1 |
| Finlets No. | Dorsal 0 - 0 |
| Ventral 0 - 0 | |
| Spines total | 0 - 0 |
| Soft-rays total | 18 - 19 |
| Adipose fin | absent |
| Attributes | forked; more or less normal |
| Fins number | 1 |
| Spines total | 0 - 0 |
| Soft-rays total | 12 - 23 |
| Pectoral | Attributes more or less normal |
| Spines 0 | |
| Soft-rays 16 | |
| Pelvics | Attributes more or less normal |
| Position abdominal before origin of D1 | |
| Spines 0 | |
| Soft-rays 7 - 7 |