| Main Ref. | Stiassny, M.L.J. and D.M. Rodriguez, 2001 |
| Utseende refererar till | |
| Bones in OsteoBase |
| specialiserade organ | |
| annat utseende | always different morphology between mature adults |
| andra färger | always different colors between mature adults |
| Anmärkningar | In mature males second dorsal and anal fins have long filamentous extensions and falcate borders, and the pectoral fins are enlarged (Ref. 39832). |
| Särskilt slående egenskaper | |
| Lateral kroppsform (shape guide) | fusiform / normal |
| Tvärsnitt | |
| Dorsal profil av huvudet | |
| Ögontyp | more or less normal |
| Typ av mun/snyte | |
| Munnens placering | superior |
| Type of scales | |
| Diagnos |
Rheocles derhami is readily distinguished from R. sikorae and R. wrightae by length of upper jaw (32-41%HL versus 46-58) and absence of black pigmentation of genital papilla, from R. pellegrini by number of gill rakers on lower limb of first arch (9-10 versus 6-7), from R. lateralis by caudal peduncle length (67.3-78.6%SL versus 84.6-96.7), and from R. alaotrensis by absence of chest and belly scales and paired predorsal scale rows (Ref. 39832). In life males normally light grey, the second dorsal, anal and caudal fins are bright silvery blue, the throat region is orange-red, light grey females are not brightly colored; preserved specimens are creamy yellow, scale rows in dorsal midline heavily pigmented and darkened (Ref. 39832). |
| Ease of Identification |
| Sidolinjer | avbruten: No |
| Fjäll längs sidolinje | |
| Porbärande fjäll längs sidolinje | |
| Fjäll i lateralserie | |
| Antal rader fjäll ovan sidolinje | |
| Antal rader fjäll under sidolinje | |
| Fjäll runt stjärtfensspole | |
| Skäggtömmar | |
| Gälspringor (endast hos hajar/rockor) | |
| Gälräfständer | |
| på undre del av gälbåge | 9 - 10 |
| på övre del av gälbåge | |
| totalt | |
| Ryggkotor | |
| preanal | |
| totalt | 35 - 38 |
| Egenskaper | |
| Antal fenor | 2 |
| Antal småfenor | Dorsal 0 - 0 |
| Ventral 0 - 0 | |
| Totalt antal hårda fenstrålar | 2 - 2 |
| Totalt antal mjuka fenstrålar | 14 - 19 |
| Fettfena | absent |
| Egenskaper | forked; more or less normal |
| Antal fenor | 1 |
| Totalt antal hårda fenstrålar | 1 - 1 |
| Totalt antal mjuka fenstrålar | 15 - 21 |
| Bröstfena | Egenskaper more or less normal |
| Fenstrålar hårda | |
| Fenstrålar mjuka | |
| Bukfenor | Egenskaper more or less normal |
| Position thoracic before origin of D1 | |
| Fenstrålar hårda | |
| Fenstrålar mjuka |