Labeo Rueppell

Sinaseli M. Tshibwabwa, Melanie L. J. Stiassny & Robert C. Schelly, 2006, Description of a new species of Labeo (Teleostei: Cyprinidae) from the lower Congo River., Zootaxa 1224, pp. 33-44 : 41-43

[[ Genus Labeo Rueppell ]]

Practical key to Labeo species from the lower Congo River

(Note: numbers in parenthesis indicate value most commonly observed)

1 Papillate lips .................................................................................................................. 2

- Plicate lips ..................................................................................................................... 4

2 Upper edge of the dorsal fin straight or convex ............................................................ 3

- Upper edge of the dorsal fin falciform (or deeply concave); 11-12 dorsal branched rays, body striped; no dark spot on caudal peduncle and scaly caudal fin; scale formula: 35-38 (37); 41/2-61/2 (51/2); 3-5 (4); 15-18 (16) ..................................... L. weeksii

3 37 scales in lateral line; 16 scales around the caudal peduncle; upper edge of the dorsal fin straight or convex, with 9-10 branched rays; body striped; a dark spot on caudal peduncle and scaly caudal fin; barbels small and hidden; scale formula: 35-38 (37); 51/ 2;3-4 (4); 15-17(16) ....................................................................................... L. lineatus

- Less than 36 scales in lateral line; less than 16 scales around the caudal peduncle; upper edge of the dorsal fin always straight; body striped, a small spot at caudal peduncle; maxillary barbels large and visible; scale formula: 30-35 (34); 51/2;4;12-15 (13) ...................................................................................... L. maleboensis

4 Upper edge of the dorsal fin convex or straight ............................................................ 5

- Upper edge of the dorsal fin concave or falciform ........................................................ 7

5 Upper edge of the dorsal fin convex ............................................................................. 6

- Upper edge of the dorsal fin straight; 10-11 branched rays; flanks striped, scale formula: 37-39 (38); 61/2-71/2 (71/2); 4-5 (5); 16-19 (16) ................................. L. rectipinnis

6 Ten branched rays at the dorsal fin; flanks striped; scale formula: 35-37 (37); 51/2-61/2 (51/2); 3-4 (4); 16-17 (16) ................................................................................. L. degeni

- 11-14 branched rays at the dorsal fin; flanks not striped; scale formula: 35-38 (37); 51/2-61/2 (51/2); 4-5 (5); 15-17 (16) ............................................................. L. longipinnis

7 Upper edge of the dorsal fin concave; flanks striped or not, dark lateral band present or absent ............................................................................................................................. 8

- Upper edge of the dorsal fin falciform (sometimes deeply concave); eyes always in supero-lateral position ................................................................................................. 15

8 Flanks striped; interorbital profile flat; snout not prominent, without a transverse furrow and a fleshy upwardly directed appendage; pectoral fins distant from the origin of the pelvic fins; anal fin not reaching the scaly caudal fin; genital opening near the origin of the anal fin; maxillary barbels well developed; scale formula: 38-39; 61/2; 4-5; 16 ............................................................................................................ L. fulakariensis

- Flanks not striped, dark lateral band present or absent ................................................. 9

9 Dark lateral band present on the flanks ....................................................................... 10

- No dark lateral band on the flanks .............................................................................. 11

10 Snout with a small transverse furrow, no fleshy appendage at its end; usually small sized; scale formula: 33-36 (35); 31/2-51/2 (41/2); 3-4 (3); 12-16 (13) .............. L. parvus

- Snout with a deep transverse furrow and a fleshy appendage at its end; usually large sized; scale formula: 37-39 (38); 41/2-61/2 (51/2); 3-4 (4); 13-16 (14) ......... L. annectens

11 Usually 10 branched dorsal fin rays, maxillary barbels small and hidden .................. 12

- Usually 12 branched dorsal fin rays, dorsal fin deeply concave; maxillary barbels large, visible at the corners of the mouth; body variegated or uniformly dark brown (sometimes vague stripes present on the flanks); snout large and rounded; scale formula: 36-38 (37); 51/2-71/2(61/2); 4-5 (5); 16-21 (16) ........................... L. cyclorhynchus

12 Eyes large, in supero-lateral position; no transverse furrow or upwardly directed fleshy appendage at the end of the snout ............................................................................... 13

- Eyes small or exceedingly small, in supero or dorso-lateral position; transverse furrow and fleshy appendage present at the end of the snout ................................................. 14

13 Maxillary and rostral barbels very large; 19-26 scales around the caudal peduncle; snout prominent; scale formula: 38-41 (40); 61/2-91/2 (81/2); 5-7 (6); 19-26 (24) ........... ....................................................................................................................... L. barbatus

- Maxillary barbels small, hidden at the corner of the mouth; rostral barbels minuscule, hidden in the rostral furrow; snout very prominent without transverse furrow or a fleshy appendage, overhanging a very large mouth; scale formula: 37-39 (38); 51/2-71/2 (61/2); 4-5 (5); 16-20 (18) ....................................................................... L. macrostomus

14 61/2 to 71/2 scale rows between the lateral line and the origin of the dorsal fin; eyes small, in dorso-lateral position; snout with a transverse furrow and a small fleshy appendage at its end; scale formula: 36-40 (38); 51/2-71/2 (61/2); 3-5 (4); 17-21 (19) ..... ............................................................................................................................ L. nasus

- More than 71/2 scale rows between the lateral line and the origin of the dorsal fin; eyes exceedingly small, in dorso-lateral position; snout with a very well developed transverse furrow and a very well developed and upward fleshy appendage at its end; scale formula: 40-43 (42); 71/2-91/2 (81/2); 5-6 (6); 20-27 (24) .................................... L. sorex

15 Less than 37 scales in lateral line; usually less than 16 scale rows around the caudal peduncle; scale formula: 33-36 (36); 31/2-51/2 (41/2); 21/2-4 (3); 12-16 (13) .................. .................................................................................................................... L. chariensis

- More than 37 scales in lateral line; 16 or more scale rows around the caudal peduncle ..................................................................................................................................... 16

16 Large and oval dark spot on the caudal peduncle and on the scaly caudal fin; scale formula: 35-39 (38); 41/2-61/2 (51/2); 3-4 (4); 15-19 (16) ...................................... L. greenii

- No spot on the caudal peduncle; maxillary barbels developed, rostral barbels minuscule, but both hidden; scale formula: 37-39 (38); 61/2-81/2 (71/2); 4-6 (5); 18-21 (19).... .................................................................................................................... L. falcipinnis