Simpsonichthys flammeus

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 : 128-130

Simpsonichthys flammeus (Costa, 1989)

(Figs. 79-80)

Cynolebias flammeus Costa, 1989: 185 ( type locality: swamp in the confluence of rio Bezerra and rio Parana , Arraias , Tocantins, Brazil [approximately 13°10’S 47°00’W; altitude about 450 m]; holotype: MNRJ 1152 ).

Material examined

Brazil: Estado do Tocantins, rio Tocantins drainage, rio Amazonas basin: MNRJ 1152 , holotype, male, 22.3 mm SL; MNRJ 11553 , 2 paratypes; MCP 12795 , 2 paratypes; UFRJ 280 , 1 ex. (c&s); Arraias, swamp in the confluence of rio Bezerra and rio Parana ; W. J. E. M. Costa, 11 Jan. 1989. UFRJ 5116 , 4; UFRJ 5117 , 2 (c&s); Peixe ; G. C. Brasil, 20 Apr. 2000. Estado de Goiás: UFRJ 2081 , 75; UFRJ 2116 , 4 (c&s); MNHN 1997.0047 , 8; UMMZ 230857 , 12; USNM 343825 , 5; MCZ 138944 , 2; swamp close to rio Parana , road Iaciara-Nova Roma ; W. J. E. M. Costa, G. C. Brasil & C. Campinha, 13 Feb. 1994. UFRJ 157 , 33; idem ; G. C. Brasil, D. Nielsen & M. T. C. Lacerda, 5 Mar. 1989.

Diagnosis

Similar to S. brunoi and distinguished from remaining species of the S. flammeus group by having iridescent blue bars on the flanks in females; similar to S. brunoi and distinguished from all other cynolebiatins by having filamentous rays along entire distal border of dorsal and anal fins in males (vs. filamentous rays, when present, restricted to tip of fin); differs from S. brunoi by having more dorsal-fin rays in males (20-23, vs. 18- 20), and consequently a longer dorsal-fin base (39.2-42.6, vs. 34.7-38.5% SL, in adult males with 25.0-30.0 mm SL), a deeper body (body depth 38.9-40.3, vs. 36.1-37.5% SL, in adult males with 25.0-30.0 mm SL), no dark zones on dorsal fin in males (vs. melanophores concentrated on the anterior portion of the fin forming a dark gray zone), and dorsolateral regions of head red, with blue spots on center of scales (vs. metallic greenish blue, without red pigmentation).

Description

Morphometric data appear in Table 7. Largest specimen examined 42.8 mm SL. Dorsal profile concave on head, convex from nape to end of dorsal-fin base, nearly straight on caudal peduncle. Ventral profile convex from lower jaw to end of anal-fin base, approximately straight on caudal peduncle. Body moderately deep, compressed, greatest body depth at level of pelvic-fin base. Eye positioned on dorsolateral portion of 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; median anal-fin rays long in females, anal fin spatula-shaped. Entire distal border of dorsal and anal fins with long filamentous rays in males, tips of longest rays reaching beyond posterior border of caudal fin. Caudal fin subtruncate in males, round in females. Pectoral fins elliptical. Posterior margin of pectoral fins reaching vertical through base of 6th anal-fin ray in males, and reaching urogenital papilla in females. Tip of each pelvic fin reaching base of 3rd anal-fin ray in males and reaching urogenital papilla in females. Pelvic-fin bases medially in close proximity. Dorsal-fin origin at vertical through urogenital papilla. Dorsal-fin origin between neural spines of vertebrae 6 and 8 in males, and neural spines of vertebrae 10 and 12 in females. Anal-fin origin between pleural ribs of vertebrae 7 and 8 in males, and pleural ribs of vertebrae 8 and 10 in females. Dorsal-fin rays 20-23 in males, 15-18 in females; anal-fin rays 20-24 in males, 18-22 in females; caudal-fin rays 24-25; pectoral-fin rays 13-14; pelvic-fin rays 6.

Frontal squamation E-patterned; E-scales overlapping medially; no row of scales anterior to H-scale; two small supraorbital scales. Longitudinal series of scales 26-27; transverse series of scales 10-11; scale rows around caudal peduncle 12. Contact organ on each scale of ventral portion of lateral surface of body in males. Small papillate contact organs on inner surface of three dorsalmost rays of pectoral fin in males. Cephalic neuromasts: supraorbital 14-17, parietal 3, anterior rostral 1, posterior rostral 1, infraorbital 2 + 22- 23, preorbital 4, otic 2, post-otic 3, supratemporal 1, median opercular 1, ventral opercular 2, preopercular 22- 24, mandibular 12, lateral mandibular 5, paramandibular 1. One or two neuromasts on each scale of lateral line. Two neuromasts on caudal-fin base.

Basihyal subtriangular, width about 55% of length; basihyal cartilage about 40-45% of total length of basihyal. Six branchiostegal rays. Second pharyngobranchial teeth 2-3. Gill-rakers on first branchial arch 4 + 11. Vomerine teeth absent. Dermosphenotic absent. Ventral process of posttemporal long. Total vertebrae 26-28.

Coloration

Males. Sides of body light blue, with 12-13 pale reddish brown bars. Venter pale orange. Posterolateral portion of head red, with blue spot on center of each scale. Opercular region metallic blue. Iris light yellow, with dark brown bar. Dorsal fin light blue with 8-10 brownish red bars, anterior bars parallel to fin rays, posterior bars crossing fin rays; filaments black. Anal fin light blue, with 6-8 brownish red bars; filaments black. Caudal fin light blue, with 5-6 brownish red bars and bright blue distal border. Pectoral fins hyaline. Pelvic fins blue.

Females. Sides of body pale brownish gray, with faint gray bars; anterocentral portion of flanks with one to three black spots, alternating with vertically elongate metallic blue spots. Venter pale golden. Opercular region pale blue. Iris light yellow, with gray bar. Unpaired fins hyaline, with faint spots; small, iridescent blue spot on posterior portion of anal fin close to caudal peduncle. Paired fins hyaline.

Distribution

Middle rio Tocantins basin between Nova Roma, Estado de Goiás, and Peixe, Estado do Tocantins, central Brazil (Fig. 4).

Habitat

Temporary pools in the Cerrado.