Simpsonichthys nigromaculatus

description

Description Morphometric data appear in Table 2. Largest specimen examined 25.6 mm SL. Dorsal profile convex from snout to end of dorsal-fin base, approximately straight on caudal peduncle. Ventral profile gently convex from lower jaw to end of anal-fin base, nearly straight on caudal peduncle. Body moderately deep, compressed, greatest body depth in vertical just anterior to anal-fin origin. Eye positioned on dorsal portion of of each side of head. Snout blunt. Urogenital papilla cylindrical and short in males, pocket-shaped in females. Tip of dorsal and anal fins gently pointed in males, rounded in females; filamentous rays absent. Dorsalfin rays unbranched. Caudal fin round. Pectoral fins elliptical. Posterior margin of each pectoral fin reaching vertical between base of 3 rd and 5 th anal-fin rays in males, and between anus and urogenital papilla in females. Pelvic fins and pelvic girdle absent. Dorsal-fin origin on vertical between base of 2 nd and 5 th anal-fin ray in males, between base of 2 nd and 3 rd anal-fin ray in females; dorsal-fin origin between neural spines of vertebrae 9 and 10 in males, and vertebrae 9 and 11 in females. Anal-fin origin between pleural ribs of ve

Taxonomic revision of the seasonal South American killifish genus Simpsonichthys (Teleostei: Cyprinodontiformes: Aplocheiloidei: Rivulidae).

diagnosis

Diagnosis Distinguished from all congeners in having 2 - 4 black spots on posterobasal portion of dorsal fin in males. It is also distinguished from all other species of Simpsonichthys by the unique combination of the following features: pelvic fin and pelvic girdle absent (vs. present), 24 - 25 vertebrae (vs. 26 - 31), second pharyngobranchial teeth absent (vs. present), ventral process of posttemporal absent (vs. long), 17 - 20 anal-fin rays in females (vs. 20 - 22), body depth 33.5 - 36.0 % SL in males (vs. 28.8 - 32.5 % SL), maximum adult size 25.6 mm SL (vs. about 40.0 mm SL), bright blue bars on flank in males much narrower than interspace (vs. approximately as wide as red bars), five alternating bright blue and pink to red bars on head side in males (vs. never a similar color pattern), short postorbital pink stripe connecting pink bars 2 and 3 (vs. stripe absent), anterior and posterior margins of iris bright blue (vs. yellow), dark gray band bordered by a bright blue line on distal margin of dorsal and anal fins, and posterior margin of caudal fin in males (vs. never a similar color pattern), ground color of dorsal and anal fins orange in males (vs. other colors, such as da

Taxonomic revision of the seasonal South American killifish genus Simpsonichthys (Teleostei: Cyprinodontiformes: Aplocheiloidei: Rivulidae).

distribution

Distribution Rio da Prata floodplains, rio Apore drainage, upper rio Parana basin, Estado de Goias, central Brazil (Fig. 1).

Taxonomic revision of the seasonal South American killifish genus Simpsonichthys (Teleostei: Cyprinodontiformes: Aplocheiloidei: Rivulidae).

materials_examined

Material examined Brazil: Estado de Goias, rio Paranaiba drainage, rio Parana basin: UFRJ 6467, holotype, male, 24.0 mm SL; UFRJ 6468, 5 paratypes; UFRJ 6469, 3 paratypes (c & s); UFRJ 6473, 2 paratypes; temporary swamp, floodplains of rio da Prata, rio Apore drainage, upper rio Parana basin, near the road GO- 050, Chapadao do Ceu, 18 º 33 ’ 2.0 ” S 52 º 37 ’ 43.1 ” W, altitude 778 m; W. J. E. M. Costa, C. P. Bove & B. B. Costa, 14 January 2007.

Taxonomic revision of the seasonal South American killifish genus Simpsonichthys (Teleostei: Cyprinodontiformes: Aplocheiloidei: Rivulidae).