Key to the species of Chrysobrycon from " A new species of Chrysobrycon (Characiformes, Characidae, Stevardiinae) from the Amazon River basin in Colombia, with a new diagnostic characteristic for the genus."

1A. 33–39 branched anal-fin rays; 17–19 circumpeduncular scales; adult males with longer and expanded anal fin and with series of spinelets developed on pelvic ,anal and caudal-fin rays ; pelvic-fin rays i,6 (rarely i,7) ; outer premaxillary row teeth with 2–4 teeth (mode=3)........................... Chrysobrycon myersi

1B. 24–32 branched anal-fin rays; 14–16 circumpeduncular scales; adult males with shorter and unexpanded anal fin and lacking spinelets on pelvic, anal and caudal-fin rays ; pelvic-fin rays i,7 (rarely i,6 or i,8 in C. eliasi or C. guahibo) ; outer premaxillary row teeth with 4–6 (mode=5 in C.eliasi ; 5 in C. guahibo ; 5 in C. hesperus ; 4 in C. yoliae) ............................. 2

2A. Anal-fin bony hooks located on nearly all branched anal-fin rays in adult males (>80% of total number of rays) ; larger specimens (usually>50mm LS) with anteriormost maxillary tooth usually pentacuspid (rarely tetracuspid); terminal lateral-line tube on middle caudal-fin rays absent .................. C. hesperus

2B. Anal-fin bony hooks distributed on anterior branched anal-fin rays 1–12 in adult males (≤50% of total number of rays) ; larger specimens (usually>30 mm LS in C. eliasi ; >28 mm LS in C. guahibo ; >30mm LS in C. mojicai ; and >35mm LS in C. yoliae) with anteriormost maxillary tooth usually tricuspid (rarely conical, bicuspid or tetracuspid) ; terminal lateral-line tube on middle caudal-fin rays present.....3

3A. Maxillary teeth 1–3 (occasionally absent in juvenile specimens) ; anal-fin bony hooks on third to seventh branched rays forming two separate series along each ray in mature males ............................................. C. guahibo

3B. Maxillary teeth 6–16 ; anal-fin bony hooks on third to seventh branched anal-fin rays forming single, continuous series along each ray in mature males.........4

4A. Distal tips of most maxillary teeth lateroventrally curved............. C. mojicai

4B. All maxillary teeth straight................................................5

5A. Dentary teeth 20–26 ; body depth at dorsal-fin origin 34•4–42•2% LS ; distance between dorsal- and adipose-fin origins 26•8–28•8% LS ; dorsal-fin origin situated at vertical between anal-fin rays 5–7................................ C. yoliae

5B. Dentary teeth 12–19 ; body depth at dorsal-fin origin 24•1–34•5% LS; distance between dorsal and adipose-fin origins 23•9–26•8% LS ; dorsal-fin origin situated at vertical between anal-fin rays 8–10 ............................... C. eliasi