Simpsonichthys punctulatus

Wilson J. E. M. Costa, 2007, Taxonomic revision of the seasonal South American killifish genus Simpsonichthys (Teleostei: Cyprinodontiformes: Aplocheiloidei: Rivulidae)., Zootaxa 1669, pp. 1-134 : 33-35

Simpsonichthys punctulatus Costa & Brasil, 2007

(Figs. 19-20)

Simpsonichthys punctulatus Costa & Brasil, 2007: 22 (original description; type locality: temporary swamp adjacent to stream tributary to rio Bezerra, rio Preto drainage, rio Sao Francisco basin, near the road BR-020 , 15º33’1.0”S 47º10’33.2”W, altitude 901 m, Município de Formosa, Estado de Goiás, Brazil; holotype: UFRJ 6478 ).

Material examined

Brazil: Estado de Goiás: Município de Formosa, rio Preto drainage, rio São Francisco basin: UFRJ 6478 , holotype, 25.5 mm SL; UFRJ 6479 , 3 paratypes; UFRJ 6480 , 5 paratypes (c&s); temporary swamp adjacent to stream tributary to rio Bezerra, near the road BR-020 , 15°33’1.0”S 47°10’33.2”W, altitude 901 m; W. J. E. M. Costa, C. P. Bove, B. B. Costa & G. C. Brasil, 24 January 2007.

Diagnosis

Distinguished from all other species of the subgenus Simpsonichthys by the presence of longitudinal rows of light blue dots on flank in males (vs. absence) and long filamentous ray on tip of dorsal fin in males, reaching posterior portion of caudal fin (vs. reaching basal portion of caudal fin). Distinguished from all congeners by the unique combination of the following features: pelvic fin present (vs. pelvic fin absent), second pharyngobranchial teeth absent (vs. present), ventral process of posttemporal short (vs. long), 18-19 dorsal-fin rays in males and 14-15 in females (vs. 15-17 in males, 12-13 in females), long filamentous ray on tip of dorsal fin in males (vs. filamentous rays short or absent), five alternating bright blue and pink to red bars on head side in males (vs. never a similar color pattern), pectoral fin pink with blue spots in males (vs. hyaline), and no black spots on dorsal fin in males (vs. black spots on basal portion of dorsal fin).

Description

Morphometric data appear in Table 2. Largest male examined 29.1 mm SL; largest female examined 24.0 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 each side of head. Snout blunt. Urogenital papilla cylindrical and short in males, pocket-shaped in females.

Tip of dorsal and anal fins pointed in males, rounded in females; dorsal fin with long filamentous ray, reaching posterior margin of caudal fin. Dorsal-fin rays unbranched. Caudal fin round. Pectoral fins elliptical. Posterior margin of each pectoral fin reaching vertical through base of 7th anal-fin ray in males, through urogenital papilla in females. Pelvic fins short and pointed, tip reaching between base of 1st and 3rd anal-fin rays in males, between anus and urogenital papilla in females. Dorsal-fin origin on vertical between base of 3rd and 4th anal-fin rays; dorsal-fin origin between neural spines of vertebrae 8 and 9 in males, and vertebrae 10 and 12 in females. Anal-fin origin between pleural ribs of vertebrae 7 and 9 in males, and vertebrae 8 and 10 in females. Dorsal-fin rays 18-19 in males, 14-15 in females; anal-fin rays 18-19 in males, 17-18 in females; caudal-fin rays 27-29; pectoral-fin rays 13.

Frontal squamation E-patterned; E-scales medially overlapping; no scale anterior to G-scale. One or two supraorbital scale. Longitudinal series of scales 25; transverse series of scales 8; scale rows around caudal peduncle 12. Minute contact organ on each scale of anteroventral portion of lateral surface of body in males. Minute papillate contact organs on medial surface of first two pectoral-fin rays in males.

Cephalic neuromasts: supraorbital 11-12, parietal 1-2, anterior rostral 1, posterior rostral 1, infraorbital 2 + 15-16, preorbital 2, otic 1, post-otic 2, supratemporal 1, median opercular 1, ventral opercular 2, preopercular12-14, mandibular 8, lateral mandibular 3-5, paramandibular 1. One neuromast on center of each scale of lateral line, sometimes absent in few scales. Two neuromasts on caudal-fin base.

Basihyal subtriangular, width about 50 % of length; basihyal cartilage about 20 % of total length of basihyal. Six branchiostegal rays. Second pharyngobranchial teeth absent. Gill-rakers on first branchial arch 2 + 9. Vomerine teeth absent. Dermosphenotic absent. Ventral process of posttemporal short. Total vertebrae 26-27.

Coloration

Males. Sides of body light red with 12-13 series of small bright blue spots, spots of four or five series coalesced to form bars; longitudinal rows of light blue dots, each dot on center of each scale of flank. Five narrow alternating light blue and light red bars on side of head; dorsolateral portion light blue with light red scale margins. Iris light yellow; brownish red bar through center of eye. Dorsal and anal fins light red with small bright blue spots, distal portion dark red without spots; basal portion of anal fin yellowish orange. Caudal fin light red with light blue dots; narrow bright blue line along entire margin of fin. Pectoral fins light red with small light blue spots on basal portion. Pelvic fins light red with light blue base.

Females. Sides of head and body light yellowish brown, with 12-13 gray bars; one or two rounded black blotches on anterocentral portion of flank. Iris yellow, with dark brown bar through center of eye. Unpaired fins hyaline; faint yellowish gray spots on dorsal and anal fins. Paired fins grayish hyaline.

Distribution

Floodplains of a stream tributary to rio Bezerra, upper rio Paracatu drainage, rio São Francisco basin, Estado de Goiás, central Brazil (Fig. 4).

Habitat

Temporary pools in Campo Úmido, in the Cerrado.