Main Ref. | Stiassny, M.L.J. and D.M. Rodriguez, 2001 |
Appearance refers to | |
Bones in OsteoBase |
Specialized organs | |
Different appearance | always different morphology between mature adults |
Different colors | always different colors between mature adults |
Remarks | In mature males second dorsal and anal fins have long filamentous extensions and falcate borders, and the pectoral fins are enlarged (Ref. 39832). |
Striking features | |
Body shape lateral | fusiform / normal |
Cross section | |
Dorsal head profile | |
Type of eyes | more or less normal |
Type of mouth/snout | |
Position of mouth | superior |
Type of scales | |
Diagnosis |
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 |
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 | |
Gill clefts (sharks/rays only) | |
Gill rakers | |
on lower limb | 9 - 10 |
on upper limb | |
total | |
Vertebrae | |
preanal | |
total | 35 - 38 |
Attributes | |
Fins number | 2 |
Finlets No. | Dorsal 0 - 0 |
Ventral 0 - 0 | |
Spines total | 2 - 2 |
Soft-rays total | 14 - 19 |
Adipose fin | absent |
Attributes | forked; more or less normal |
Fins number | 1 |
Spines total | 1 - 1 |
Soft-rays total | 15 - 21 |
Pectoral | Attributes more or less normal |
Spines | |
Soft-rays | |
Pelvics | Attributes more or less normal |
Position thoracic before origin of D1 | |
Spines | |
Soft-rays |