Spectrolebias pilleti, a new annual Killifish (Cyprinodontiformes: Rivulidae: Cynolebiatinae) from the upper río Mamoré basin, Bolivia

Spectrolebias pilleti n. sp. is described from a temporary pool from the upper rio Mamore basin, Departamento Santa Cruz, Quimone city, Bolivia. The new species is dis- tinguished from all congeners by the unique color pattern of males:3 to 5 vertical blue bars alternating with a light reddish brown background in males (vs. absence of bars), by the presence of an iridescent blue spot on the flank in female (vs. presence of one or more black spots), by the absence of filaments at the tips of dorsal fin and anal fin in males, except Spectrolebias reticulatus (vs. long filaments on dorsal and anal fins in S. brousseaui and S. filamentosus, fil- aments on the dorsal fins of S. semiocellatus and S. inae- quipinnatus, or filaments in the anal fins of S. chacoensis) and by the presence of scales covering the base of anal fin in males (vs. absence of these scales in the remaining con- geners). Also distinguished from all congeners, with the exception of S. reticulatus, by the position of the dorsal fin, which has its origin anterior to the origin of the anal fin in males.