Hemibrycon (Malabarba & Weitzman, 2003)

Bertaco, Vinicius A. & Malabarba, Luiz R., 2010, A review of the Cis-Andean species of Hemibrycon Günther (Teleostei: Characiformes: Characidae: Stevardiinae), with description of two new species, Neotropical Ichthyology 8 (4), pp. 737-770 : 768-769

Key to the Cis-Andean species of Hemibrycon

1. Humeral spot extending over 7 to 9 horizontal series of scales…………………..…………………..…..…..…..…2

1’. Humeral spot extending over 2 to 6 horizontal series of scales…………………………………………………………3

2. 19 to 23 branched anal-fin rays; 6 to 12 scales sheath along anal-fin base; 16 to 18 predorsal scales…………… H. helleri (upper río Ucayali drainage, Peru)

2’. 25 to 30 branched anal-fin rays; 13 to 28 scales sheath along anal-fin base; 12 to 16 predorsal scales…… H. jelskii (upper portions of ríos Marañon, Ucayali, Madeira- Mamoré drainages in Bolivia, Brazil and Peru)

3. Small humeral spot and extending over 2 to 3 horizontal series of scales; total number of pelvic fin rays 7; 3 to 4 scale rows below of the lateral line……… H. mikrostiktos (upper río Ucayali drainage, Peru)

3’. Humeral spot extending over 4 to 6 horizontal series of scales; total number of pelvic fin rays 8; 4 to 9 scale rows belowofthelateralline………………………………………4

4. Presence of a wide black asymmetrical spot covering base of caudal-fin rays and extending along entire length of caudal-finrays 9 to 12-13………………..…………….……5

4’. Absence of a wide black asymmetrical spot covering base ofcaudal-finrays……………………………………………6

5. Presence of a black band in the lower half of the caudal peduncle from the region above the last anal-fin rays to the caudal-fin base; scale sheath along anal-fin base 17 to 22; total number of gill rakers 20 to 22…………… H. divisorensis (upper río Ucayali drainage, Peru)

5’. Absence of a black band in the lower half of the caudal peduncle from the region above the last anal-fin rays to the caudal-fin base; scale sheath along anal-fin base 1 2 -17; total number of gill rakers 19 to 20……………………………………… H. surinamensis (coastal basins of French Guiana and Suriname, and lower rios Tocantins, Tapajós and Xingu basins, Brazil)

6. Branchedanal-finrays 15 to19………………………………7

6’. Branched anal-fin rays 22 to 31……………………………8

7. Lateral line scales 39; 6 scale rows above of the lateral line; 14 scales around caudal-peduncle……………… H. tridens (upper río Ucayali drainage, Peru)

7’. Lateral line scales 44 to 53; 7 to 8 scale rows above of the lateral line; 16 to 18 scales around caudal-peduncle………… H. beni (río Beni drainage, Bolivia)

8. Gill rakers 16-18; scales sheath along anal-fin base 6- 10………………………………………………… H.inambari (upper río Madre de Dios drainage, Peru)

8’. Gill rakers 19-21; scales sheath along anal-fin base 10- 24…………………..…………………..…..…..…..………9

9. Lateral line scales 40 to 42 (usually 41); 7 to 8 scale rows above of the lateral line; head and body slim …………………..…………………..…..…..…..…………10

9’. Lateral line scales 42 to 48 (usually 44-45); 8 to 10 scale rows above of the lateral line; head and body robust …………………..…………………..…..…..…..…………11

V. A. Bertaco & L. R. Malabarba 769

10. Second tooth of premaxillary inner row teeth heptacuspidate; humeral spot extending over 5 to 6 (usually 5) horizontal series of scales……………………… H. metae (río Orinoco drainage, Venezuela and Colombia)

10’. Second tooth of premaxillary inner row teeth pentacuspidate; humeral spot extending over 4 to 5 (usually 4) horizontal series of scales…………………… H. taeniurus (rivers of Island Trinidad, Trinidad and Tobago)

11. Caudal peduncle scales 18to 20; head length 22.0-26.0% of SL; upperjawlength 45.2-52.6% ofHL………… H. huambonicus (río Huallaga drainage, Peru)

11’. Caudal peduncle scales 16; head length 20.9-22.9% of SL; upper jaw length 43.7-45.6% of HL……… H. polyodon (río Pastaza drainage, Ecuador)