Simpsonichthys hellneri

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 : 81-85

Simpsonichthys hellneri (Berkenkamp, 1993)

(Figs. 53-54)

Cynolebias hellneri Berkenkamp, 1993: 8 ( type locality: road Januaria-Manga , about 10.5 km from Itacarambi, Municipio de Manga , Estado de Minas Gerais, Brazil [about 14º50’S 44º10’W] ; holotype designated in the original description, but uncatalogued).

Material examined

Brazil: Estado de Minas Gerais, rio São Francisco basin: UFRJ 2070 , 1; temporary pool 25 km N from Itacarambi ; W. J. E. M. Costa, G. C. Brasil & C. Campinha, 8 Feb. 1994. UFRJ 2120 , 1; temporary pool 7 km S from Sao Francisco ; G. C. Brasil, 13 Mar. 1994. UFRJ 2093 , 33; UFRJ 2080 , 4 (c&s); UMMZ 230856 , 10; MNHN 1997-0050 , 4; USNM 343819 , 3; MCZ 138942 , 10; swamp 1 km N from Sao Francisco ; W. J. E. M. Costa, G. C. Brasil & C. Campinha, 8 Feb. 1994. UFRJ 4800 , 41; UFRJ 4989 , 8 (c&s); temporary pool 10 km N from Itacarambi ; W. J. E. M. Costa, F. Pupo & E. Araujo, 9 Feb. 1999. UFRJ 4801 , 16; temporary pool 10.5 km N from Itacarambi ; W. J. E. M. Costa, F. Pupo & E. Araujo, 9 Feb. 1999. UFRJ 4766 , 9; temporary pool 11 km N from Itacarambi ; W. J. E. M. Costa, F. Pupo & E. Araujo, 9 Feb. 1999. UFRJ 3802 , 7; temporary pool 4 km N from Sao Francisco ; A. L. F. Cyrino, D. T. B. Nielsen, J. L. Cruz & A. De Luca, 27 Jan. 1996. UFRJ 3807 , 6; temporary pool at the road Itacarambi-Manga ; A. L. F. Cyrino, D. T. B. Nielsen, J. L. Cruz & A. De Luca, 27 Jan. 1996

Diagnosis

Distinguished from all other species of the S. magnificus group by possessing long filamentous rays on tips of both dorsal and anal fins in males, reaching posterior margin of the caudal fin (vs. filaments, when present, reaching a vertical through base or middle of caudal fin), and round minute bright blue spots on flanks in males (vs. vertically elongated minute bright blue spots at least on anterior portion of flanks).

Description

Morphometric data appear in Table 5. Largest specimen examined 37.4 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 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 both dorsal and anal fins gently pointed in males, rounded in females. Long filamentous rays on tip of dorsal and anal fins in males, tip reaching vertical through posterior margin of caudal fin. Dorsal-fin rays unbranched. Caudal fin rounded. Pectoral fins elliptical. Posterior margin of pectoral fins reaching vertical between base of 5th and 7th anal-fin ray in males, and between urogenital papilla and base of 2nd anal-fin ray in females. Tip of pelvic fins reaching between base of 2nd and 5th anal-fin ray in males and base of 1st or 2nd anal-fin ray in females. Pelvic-fin bases in close proximity. Dorsal-fin origin slightly anterior, or slightly posterior, or on vertical through anal-fin origin in males; dorsal-fin origin through base of 4th or 5th anal-fin ray in females; dorsal-fin origin between neural spines of vertebrae 7 and 9 in males, and neural spines of vertebrae10 and 12 in females. Anal-fin origin between pleural ribs of vertebrae 7 and 9 in males, and pleural ribs of vertebrae 8 and 10 in females. Dorsal-fin rays 19-23 in males, 14-18 in females; anal-fin rays 20-23 in males, 17-21 in females; caudal-fin rays 22-25; pectoral-fin rays 12-13; pelvic-fin rays 6.

Frontal squamation E-patterned; E-scales slightly overlapping medially; no row of scales anterior to G- scale; supraorbital scales absent. Longitudinal series of scales 25-26; transverse series of scales 11; scale rows around caudal peduncle 12. Contact organ on each scale of anteroventral portion of flank in males. Contact organs absent from pectoral fins.

Cephalic neuromasts: supraorbital 10-12, parietal 3-4, anterior rostral 1, posterior rostral 1, infraorbital 2 + 20-23, preorbital 3, otic 1-2, post-otic 2, supratemporal 1, median opercular 1, ventral opercular 1-2, preopercular15-16, mandibular 8-10, lateral mandibular 3-4, paramandibular 1. One or two neuromasts on each scale of lateral line. 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 1-2. Gill-rakers on first branchial arch 2 + 9. Vomerine teeth absent. Dermosphenotic absent. Ventral process of posttemporal long. Total vertebrae 26-29.

Coloration

Males. Sides of body dark yellow ochre on anterior half, dark purplish pink on posterior half of flank; 9- 11 dark gray bars, three anterior bars bluish dark gray, almost black, alternating with three red bars; minute blue spots on entire flank; venter yellowish white. Sides of head yellow ochre, opercular region greenish golden with blue small spots; margin of dorsoposterior scales red. Iris light yellow, with dark reddish brown bar through center of eye. Unpaired fins dark red, with metallic blue dots on dorsal and anal fins, and metallic blue lines on fin membranes of anal fin, parallel to fin rays. Pelvic fins bright blue, anterior rays dark red. Pectoral fins hyaline.

Females. Sides of body light gray, with irregularly shaped dark brown spots, arranged in irregular horizontal rows; anterior spots often horizontally coalescent; venter pale golden; one or two rounded black blotches on anterocentral portion of flanks. Opercular region pale greenish golden. Iris light yellow, with gray bar through center of eye. Unpaired fins hyaline, with dark gray spots on basal region; spots of anal fin elongate and parallel to fin rays; small light blue spot on posterior margin of anal fin, just posterior to fin base. Paired fins hyaline.

Distribution

Floodplains of middle rio São Francisco, between Manga and São Francisco, Estado de Minas Gerais, Brazil (Fig. 4).

Habitat

Temporary pools in the Caatinga.