Taxonomic revision of the seasonal South American killifish genus Simpsonichthys (Teleostei: Cyprinodontiformes: Aplocheiloidei: Rivulidae). Author Wilson J. E. M. Costa text Zootaxa 2007 1669 1 134 http://www.zoobank.org/urn:lsid:zoobank.org:pub:F23FABE8-719E-4F7E-B225-A9C5D45CCFCE journal article z01669p001 Simpsonichthys cholopteryx Costa, Moreira & Lima, 2003 (Figs. 13-14) Simpsonichthys cholopteryx Costa, Moreira & Lima, 2003: 140 ( type locality: ribeirao do Sapo, rio Araguaia basin, on road MT 100, 31 km S of Alto Araguaia , Estado de Mato Grosso , Brazil , 17°33’38.5”S 53°18’33.1”W ; holotype : MZUSP 78061 ). Material examined Brazil : Estado de Mato Grosso : Municipio de Alto Araguaia, upper rio Araguaia drainage, rio Amazonas basin: MZUSP 78061 , holotype , male, 23.5 mm SL; UFRJ 5428 , 29 paratypes ; Ribeirao do Sapo on road MT 100, 31 km S of Alto Araguaia , 17°33’38.5”S 53°18’33.1”W ; W. J. E. M. Costa, S. M. Q. Lima, D. F. Belote & E. S. Araujo , 6 Apr. 2002 . MZUSP 73338 , 16 paratypes (6 c&s); Ribeirao do Sapo, km 464 of Ferronorte railway , 17°31’11”S 53°15’33”W ; C. L. R. Moreira & F. C. T. Lima , 21 May 2001 . MZUSP 73323 , 41 paratypes ; Corrego do Sapinho, km 474 of Ferronorte railway ( 17°25’55”S 53°14’34”W ); C. L. R. Moreira & F. C. T. Lima , 19 May 2001 . Diagnosis Distinguished from all other congeners by the combination of the following features: absence of pelvic fins and pelvic girdle (vs. presence); dorsal-fin origin posterior (vs. anterior) to anal-fin origin, 16-18 dorsalfin rays in males (vs. 19-22), 20-23 anal-fin rays in males (vs. 17-19), 20-22 anal-fin rays in females (vs. 17- 20), maximum adult size 23.5 mm SL (vs. 40.0 mm SL), distal border of both dorsal and anal fins dark gray in males (vs. dark red), posterior border of caudal fin dark gray in males (vs. pale pink), iridescent dots on unpaired fins absent in males (vs. present), pectoral fins hyaline in males (vs. red)), with metallic blue spots in males; iris blue in males (vs. yellow), iridescent blue bars on flank approximately as wide as red bars in males (vs. much narrower), ground color of dorsal and anal fins light blue anteriorly, yellow posteriorly in males (vs. whole fins orange), and presence of dark bars on unpaired fins in males (vs. bars absent). Description Morphometric data appear in Table 2. Largest specimen examined 23.5 mm SL. Dorsal profile convex from snout 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 point just anterior to anal-fin base. Eye positioned on dorsal portion of head side. Snout blunt. Urogenital papilla cylindrical and short in males, pocket-shaped in females. Tip of both dorsal and anal fins pointed in males, rounded in females; filamentous rays absent. Dorsal-fin rays unbranched. Caudal fin rounded. Pectoral fins elliptical. Posterior margin of each pectoral fin reaching vertical through base of third or fourth anal-fin ray in males, and vertical just anterior to anus in females. Pelvic fins and pelvic girdle absent. Dorsal-fin origin on vertical through base of 5th anal-fin ray in males, and 2nd anal-fin ray in females; dorsal-fin origin between neural spines of vertebrae 9-11 in males, and vertebrae 10-12 in females. Anal-fin origin between pleural ribs of vertebrae 7-10 in males, and vertebrae 9-10 in females. Dorsal-fin rays 17-18 in males, 15-17 in females; anal-fin rays 20-23 in males, 20-22 in females; caudal-fin rays 23-25; pectoral-fin rays 13. Frontal squamation E-patterned; E-scales medially overlapped; no scale anterior to G-scale; one supraorbital scale. Longitudinal series of scales 22-24; transverse series of scales 8-10; scale rows around caudal peduncle 14-16. Minute contact organ on each scale of ventral portion of lateral surface of body in males. No contact organs on pectoral-fins. Cephalic neuromasts: supraorbital 2 + 5-7, parietal 2, anterior rostral 1, posterior rostral 1, infraorbital 1 + 11-14, preorbital 2, otic 1, post-otic 2, supratemporal 1, median opercular 1, ventral opercular 1, preopercular 7, mandibular 4, lateral mandibular 2, paramandibular 1. One neuromast on center of each scale of lateral line. Two neuromasts on caudal-fin base. TABLE 2. Morphometric data of species of the subgenus Simpsonichthys .
S. cholopteryx S. parallelus S. nigromaculatus
males females males females males females
(n = 7) (n = 7) (n = 5) (n = 5) (n = 5) (n = 3)
Standard length (mm) 18.7-23.5 15.5-19.5 17.7-22.6 19.3-20.3 19.4-25.6 14.9-21.9
Percents of standard length
Body depth 32.5-35.2 29.7-32.9 28.8-32.6 32.1-34.8 33.5-36.0 31.4-33.3
Caudal peduncle depth 17.1-19.1 15.8-16.8 15.4-16.9 14.8-15.8 15.5-16.7 14.8-15.3
Pre-dorsal length 56.0-59.1 61.3-68.1 52.8-57.3 61.6-63.8 52.0-56.4 59.6-62.5
Pre-pelvic length - - - - - -
Length of dorsal-fin base 31.1-35.9 24.4-29.1 32.3-34.3 24.6-28.7 31.0-35.5 25.5-27.9
Length of anal-fin base 38.8-41.8 27.9-32.7 38.8-41.7 26.7-30.5 35.7-39.8 28.3-29.3
Caudal-fin length 32.4-37.6 32.6-37.2 34.9-40.9 33.3-37.9 35.6-40.2 36.6-39.3
Pectoral-fin length 23.0-25.1 21.7-22.8 23.4-25.9 22.9-24.0 23.8-27.1 21.4-24.1
Pelvic-fin length - - - - - -
Head length 28.8-31.1 28.9-32.2 28.7-32.2 31.2-33.4 29.9-31.5 31.2-32.6
Percents of head length
Head depth 91.2-97.9 86.3-93.4 85.8-96.9 87.2-98.3 92.8-102.2 85.2-88.1
Head width 64.2-72.9 65.1-73.0 65.2-71.3 66.2-69.6 63.4-68.8 64.0-66.5
Snout length 11.0-13.7 10.0-13.6 10.5-14.0 9.2-13.9 10.4-12.8 9.9-11.6
Lower jaw length 15.0-18.1 13.8-17.8 18.7-22.1 18.0-20.6 14.4-17.7 10.3-15.2
Eye diameter 34.6-39.4 36.2-42.3 35.1-38.8 35.9-39.7 36.0-37.3 35.3-37.9
continued.
S. punctulatus S. boitonei S. santanae S. zonatus
males females males females males females males females
(n = 2) (n = 2) (n = 10) (n = 10) (n = 4) (n = 4) (n = 5) (n = 4)
Standard length (mm) 25.5-29.1 19.4-24.0 22.2-26.1 18.4-20.1 18.9-23.6 17.2-18.6 19.5-29.4 17.5-22.3
Percents of standard length
Body depth 30.9 29.2-29.7 30.6-33.3 29.2-32.9 29.7-31.1 30.4-32.4 27.4-32.4 29.3-32.3
Caudal peduncle depth 15.3-16.3 14.4-13.6 13.7-14.9 13.2-15.4 14.5-15.4 13.6-14.4 13.7-15.4 13.6-15.9
Pre-dorsal length 52.6-53.3 61.9-64.9 47.0-50.0 60.4-62.6 49.8-51.7 59.8-63.0 55.4-59.6 61.3-64.7
Pre-pelvic length 44.6-46.3 52.1-54.7 - - 47.1-53.7 53.7-54.9 46.7-50.7 51.6-53.5
Length of dorsal-fin base 31.0-31.5 20.4-20.5 33.3-36.2 19.8-22.1 32.1-36.6 19.5-23.4 23.5-28.1 18.6-21.1
Length of anal-fin base 32.4-33.6 21.0-22.1 27.6-30.8 19.1-20.9 31.0-32.1 19.7-22.7 30.9-31.7 24.0-25.9
Caudal-fin length 40.8-41.3 38.8-39.1 35.8-40.6 32.4-35.9 36.2-40.0 34.4-36.3 35.9-38.5 30.4-33.3
Pectoral-fin length 29.3-30.7 24.6-25.9 27.4-30.8 24.9-26.9 27.2-30.3 23.5-26.5 23.5-26.6 23.9-23.5
Pelvic-fin length 9.0-9.4 5.3-8.3 - - 6.1-7.4 5.9-7.3 5.7 4.0-4.8
Head length 30.3-30.4 31.4-31.6 30.4-32.9 31.5-33.5 31.2-33.3 33.0-35.0 30.8-33.9 32.3-34.1
Percents of head length
Head depth 87.8-89.7 84.6-89.3 87.6-96.4 84.4-95.9 83.1-90.0 81.1-87.1 82.9-89.0 83.0-85.9
Head width 65.0-68.4 68.3-73.1 61.8-69.1 69.0-72.3 61.8-67.0 63.8-66.3 63.7-68.4 62.8-73.1
Snout length 13.3-14.5 12.5-13.6 13.9-16.6 12.9-14.5 12.4-13.6 13.0-14.5 12.6-13.4 12.6-12.8
Lower jaw length 18.6-19.3 14.8-14.9 17.9-19.7 14.0-15.8 15.3-18.3 14.6-15.3 14.4-16.4 12.3-14.4
Eye diameter 34.7-35.0 35.1-36.8 31.0-33.0 32.0-33.4 31.4-33.7 32.6-35.3 29.9-34.7 31.1-34.6
Basihyal subtriangular, width about 30% 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 + 8. Vomerine teeth absent. Dermosphenotic absent. Ventral process of posttemporal absent. Total vertebrae 24-26. FIGURE 13. Simpsonichthys cholopteryx , male, MZUSP 78061, holotype, 23.5 mm SL; Brazil: Mato Grosso: Alto Araguaia. FIGURE 14. Simpsonichthys cholopteryx , female, UFRJ 5428, paratype, 18.6 mm SL; Brazil: Mato Grosso: Alto Araguaia. Coloration Males. Body and head pale brown; flanks with 10-11 dark red bars alternating with iridescent dark blue bars; sides of head with four dark red bars, one below eye and three on opercular region, alternating with four light blue bars. Iris greenish blue, with dark reddish brown bar. Dorsal fin yellow, light blue on anterior portion, with six to seven pale brown bars; distal dark gray stripe, ventrally bordered by metallic green line. Anal fin light blue on anterior and yellow on posterior half, with six pale brown bars; distal dark gray stripe, dorsally bordered by metallic blue line. Caudal fin yellow, with four to five brown bars; dark gray band along distal margin, proximally bordered by faint iridescent green line. Pectoral fins hyaline. Females. Sides of body pale brownish yellow, with 11 dark gray bars; two or three black blotches on anterocentral portion of flank. Sides of head pale brownish yellow, with pale green iridescence on opercular region , and with dark brown bars, three on opercular region, one adjacent to posterior edge of eye, and one on suborbital region. Unpaired fins hyaline, with dark gray spots; anterior portion of anal fin pale orange. Pectoral fins hyaline.
Distribution Upper rio Araguaia basin, Estado de Mato Grosso, central Brazil (Fig. 1). Habitat Temporary pools between Campo Umido and Buritizal in the Cerrado.