Simpsonichthys notatus

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 : 66-68

Simpsonichthys notatus (Costa, Lacerda & Brasil, 1990)

(Figs. 41-42)

Cynolebias notatus Costa, Lacerda & Brasil, 1990: 10 ( type locality: temporary pool in Municipio de Alvorada do Norte [road between Alvorada do Norte and Flores de Goias ] , Estado de Goiás, Brazil [approximately 14°30’S 46°50’W; altitude about 490 m]; holotype: MZUSP 39985 ).

Material examined

Brazil: Estado de Goiás, rio Tocantins drainage, rio Amazonas basin: MZUSP 39985 , holotype, male, 25.2 mm SL; MZUSP 39986 , 3 paratypes; MNRJ 11559 , 2 paratypes; UFRJ 155 , 10; UFRJ 268 , 1 (c&s); road between Alvorada do Norte and Flores de Goias , rio Parana drainage ; M. T. C. Lacerda, G. C. Brasil & D. Nielsen, 4 Mar. 1989 . UFRJ 6107 , 11; UFRJ 6108 , 4 (c&s); UFRJ 6443 , 2; same locality ; G. C. Brasil, 23 Apr. 2005 . UFRJ 6444 , 14; UFRJ 6445 , 6; 3 km from Flores de Goias , rio Parana floodplains ; G. C. Brasil, 22 Apr. 2005 . MNRJ 11557 , 3; rio Parana floodplains, Nova Roma ; M. T. C. Lacerda, G. C. Brasil & D. Nielsen, 5 Mar. 1989 . UFRJ 2068 , 23; UMMZ 230860 , 4; MCZ 138945 , 6; swamp close to rio Parana , road Iaciara - Nova Roma ; W. J. E. M. Costa, G. C. Brasil & C. Campinha, 13 Feb. 1994 . UFRJ 5415 , 17; UFRJ 5416 , 5 (c&s); temporary pool 2 km N of Ribeirao Canabrava , 15°03’0.4”S 47°04’3.3”W; altitude 449 m; W. J. E. M. Costa, C. P. Bove & B. B. Costa, 25 Jan. 2002 .

Diagnosis

Distinguished from all other species of the S. notatus group by having bright blue dots restricted to dorsal portion of caudal fin in males (vs. dots on whole fin). Similar to S. radiosus , S. similis , S. gibberatus , S. trilineatus , and S. auratus , and distinguished from the remaining species of the S. notatus group by having one or two black blotches on anterocentral portion of flank in males (vs. blotch absent). Similar to S. radiosus , and distinguished from S. similis , S. trilineatus , and S. auratus by having oblique dark gray bars on anal fin in males (vs. bars absent), a bright blue stripe on distal edge of dorsal fin in males (vs. distal blue stripe absent), and by the absence of white dots on anal fin in males (vs. presence). Differs from S. radiosus by the absence of blue stripes on the caudal fin in males (vs. presence).

Description

Morphometric data appear in Table 4. Largest specimen examined 33.5 mm SL. Dorsal profile slightly convex on head, convex from nape 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 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. Short filamentous rays on tip of dorsal and anal fin in males, tip reaching vertical through middle of caudal fin. All dorsal-fin rays usually unbranched, sometimes median rays branched. Caudal fin rounded. Pectoral fins elliptical. Posterior margin of each pectoral fin reaching vertical between base of 4th and 6th anal-fin ray in males, and urogenital papilla in females. Tip of each pelvic fin reaching between base of 2nd and 4th anal-fin ray in males, and between urogenital papilla and base of 1st anal-fin ray in females. Pelvic-fin bases in close proximity. Anal-fin origin on vertical between base of 2nd and 4th dorsal-fin ray in males; anal-fin origin on vertical just anterior, or just posterior, or through dorsal-fin origin in females. 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 9 and 10 in females. Dorsal-fin rays 21-25 in males, 15-19 in females; anal-fin rays 20-24 in males, 17-19 in females; caudal-fin rays 22-26; pectoral-fin rays 12-13; pelvic-fin rays 6.

Frontal squamation A-patterned; E-scales medially overlapping; no scale anterior to G-scale. Longitudinal series of scales 25-27; transverse series of scales 10-11; scale rows around caudal peduncle 12. Contact organ on each scale of anteroventral portion of flank in males. Small papillate contact organs on inner surface of dorsalmost ray of pectoral fin in males.

Cephalic neuromasts: supraorbital 12-15, parietal 3, anterior rostral 1, posterior rostral 1, infraorbital 2 + 18- 20, preorbital 3, otic 2, post-otic 2, supratemporal 1, median opercular 1, ventral opercular 2, preopercular 15, mandibular 11-14, lateral mandibular 4-6, paramandibular 1. One neuromast on center of each scale of lateral line. Two neuromasts on caudal-fin base.

Basihyal subtriangular, width about 75% of length; basihyal cartilage about 25% of total length of basihyal. Six branchiostegal rays. Second pharyngobranchial teeth 1-2. Gill-rakers on first branchial arch 3 + 9. Vomerine teeth absent. Dermosphenotic absent. Ventral process of posttemporal long. Total vertebrae 26- 28.

Coloration

Males. Sides of body dark yellow ochre, with 8-10 dark purplish gray bars and light blue dots; one or two black blotches on anterocentral portion of flanks, rarely blotches absent; venter pale orangish golden. Sides of head yellow ochre, with small green spots on opercular region; often scales of laterodorsal portion with red margin. Iris light yellow, with dark reddish brown bar through center of eye. Dorsal fin reddish or orangish brown, with light blue dots; row of blue dots on distal margin of fin. Anal fin orangish brown, with dark brownish gray bars. Caudal fin reddish or orangish brown, with light blue dots on dorsal half of fin, dots sometimes absent; blue line on margin of dorsal half of fin. Pelvic fins dark orangish brown. Pectoral fins hyaline.

Females. Sides of body light brownish gray, with dark gray spots, sometimes horizontally coalescent on anterior portion and vertically coalescent on posterior portion of flanks; venter pale golden; three to five rounded black blotches on anterocentral portion of flank. Opercular region pale greenish golden. Iris light yellow, with gray bar through center of eye. Unpaired fins hyaline, with faint gray spots on basal region; small light blue spot on posterior margin of anal fin, just posterior to fin base. Paired fins hyaline.

Distribution

Rio Paranã drainage, upper rio Tocantins basin, Estado de Goiás, central Brazil (Fig. 1).

Habitat

Temporary pools in the Cerrado.