Taxonomic revision of the seasonal South American killifish genus Simpsonichthys (Teleostei: Cyprinodontiformes: Aplocheiloidei: Rivulidae). Wilson J. E. M. Costa Zootaxa 2007 1669 1 134 4XG5L Rivulidae Simpsonichthys CoL Animalia Cyprinodontiformes 54 Chordata species notatus urn:lsid:zoobank.org:act:C2C14E47-3B21-4111-9EAC-E384DDD527DF Rivulidae Simpsonichthys CoL Animalia Simpsonichthys ocellatus Costa, Nielsen & de Luca 2001:25 Cyprinodontiformes 55 Chordata species ocellatus  Diagnosis Distinguished from other congener groups in having frontal squamation A-patterned (vs. E or F-patterned) (sometimes also occurring in S. ocellatus).  Distribution Middle rio Jequitinhonha, upper rio Tocantins and middle rio SaoFrancisco basins (Fig. 1).  Key to species of the S. notatusgroup 1a. No metallic colors on flank in females ................................................................................................... 2 1b. Large black blotch, with wide bluish silver to light golden outline on anterocentral portion of flanks in females ................................................................................................................................... S. ocellatus 2a(1a). Black blotch on anterocentral portion of flanks in males ....................................................................... 5 2b(1a). Black blotch never on flanks in males .................................................................................................... 3 3a(2b). Elongated bright blue spots alternating with black interspace on dorsal-fin base in males; anal-fin origin between pleural ribs of vertebrae 7 and 9 in males, 9 and 11 in females.. ..................................... 4 3b(2b). Bright blue dots over entire dorsal fin in males; anal-fin origin between pleural ribs of vertebrae 9 and 10 in males, 11 and 12 in females.. .............................................................................................. S. rufus 4a(3a). Distal dark gray to black stripe on anal fin in males; caudal fin brownish red, with small blue rounded spots.. ...................................................................................................................................... S. stellatus 4b(3a). No distal stripe on anal fin in males; caudal fin yellow with blue stripes ............................... S. nielseni 5a(2a). Anal fin with bright dots and no bars in males; no distal stripe on dorsal fin in males.. ....................... 7 5b(2a). Anal fin with oblique dark gray bars and no bright dots in males; bright blue stripe on distal edge of dorsal fin in males ................................................................................................................................... 6 6a(5b). Caudal fin with blue dots and marginal blue stripe on its dorsal half in males; blue dots over entire flank in males; tip of each pectoral fin reaching between base of 5th and 7th anal-fin rays in males ........ ............................................................................................................................................... S. notatus 6b(5b). Caudal fin with light blue stripes parallel to fin rays, alternating with subdistal rounded light blue spots in males; few blue dots over dorsal portion of flank in males; tip of pectoral fin reaching between base of 1st and 3rd anal-fin rays in males .................................................................................. S. radiosus 7a(5a). Anterior portion of flank bright golden in males; humeral dark brown blotch in males; flank with dark gray spots in females ............................................................................................................................... 8 7b(5a). Anterior portion of flanks dark metallic yellow ochre in males; no humeral marks; flanks with dark gray bars in females ................................................................................................................................ 9 8a(7a). Pronounced convexity on anterior dorsal profile in females; no distinctive distal row of bright blue spots on dorsal fin in males ................................................................................................. S. gibberatus 8b(7a). No pronounced convexity on anterior dorsal profile in females; distinctive distal row of bright blue spots on dorsal fin in males ........................................................................................................ S. similis 9a(7b). 3-5 black blotches on anterior portion of flanks in males; pectoral fins pale red. .........................................................................10 9b(7b). 7-13 black blotches on anterior portion of flanks in males; pectoral fins hyaline ............................................... S. virgulatus 10a(9a).Five pelvic-fin rays; posterior portion of flank with three purplish brown stripes in males; no dark brown blotch on anteroventral portion of flank in males... .................................................. S. trilineatus 10b(9a).Six pelvic-fin rays; posterior portion of flank with purplish brown bars in males; dark brown blotch on anteroventral portion of flank in males.. ............................................................................. S. auratus