Simpsonichthys similis

description

Description Morphometric data appear in Table 4. Largest specimen examined 43.3 mm SL. Dorsal profile convex from snout to end of dorsal-fin base, approximately straight on caudal peduncle. Ventral profile convex from lower jaw to end of anal-fin base, nearly straight on caudal peduncle. Body moderately deep, compressed, greatest body depth at level of pelvic-fin base. Eye positioned on dorsal portion of head side. Snout blunt. Urogenital papilla cylindrical and short in males, pocket-shaped in females. Tip of dorsal and anal fins slightly pointed in males, rounded in females. Short filamentous rays on tip of dorsal and anal fins in males, tip of filaments reaching vertical through caudal-fin base. Dorsal-fin rays unbranched. Caudal fin rounded. Pectoral fin elliptical. Posterior margin of each pectoral fin reaching vertical through base of 2 nd anal-fin ray in males, and through pelvic-fin base in females. Tip of each pelvic fin reaching base of 2 nd anal-fin ray in males, and urogenital papilla in females. Pelvic-fin bases in close proximity. Anal-fin origin on vertical through base of 3 rd dorsal-fin ray in males, through base of 1 st dorsal-fin ray in females; dorsal-fin origin

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

diagnosis

Diagnosis Distinguished from remaining species of S. notatus group in possessing the following combination of characters: often one or two black blotches on anterocentral portion of flanks in males (vs. blotch always absent), white dots on all unpaired fins in males (vs. never all fins with light dots), row of small blue spots on distal margin of dorsal fin in males (vs. distal blue stripe or no distinctive distal blue mark), anterior portion of flanks dark metallic yellow ochre in males (vs. bright golden), and absence of humeral dark brown blotch in males (vs. presence).

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

distribution

Distribution Rio Urucuia drainage, middle rio Sao Francisco basin, Estado de Minas Gerais, Brazil (Fig. 1).

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

materials_examined

Material examined Brazil: Estado de Minas Gerais, rio Urucuia drainage, rio Sao Francisco basin: MZUSP 51834, holotype, male, 28.4 mm SL; MZUSP 51835, 1 paratype; UFRJ 4146, 1 paratype female; UFRJ 4147, 5 paratypes (c & s); temporary pool close to Urucuia; S. Hellner & K. Schoelzel, Apr. 1995. UFRJ 4148, 1 paratype; born in aquarium, descendant of fishes collected with the holotype.

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