Pituna poranga Costa

Costa, Wilson J. E. M., 2007, Taxonomy of the plesiolebiasine killifish genera Pituna, Plesiolebias and Maratecoara (Teleostei: Cyprinodontiformes: Rivulidae), with descriptions of nine new species, Zootaxa 1410, pp. 1-41 : 9-11

Pituna poranga Costa

( Figs. 4–5 )

Pituna poranga Costa, 1989a: 226 (type locality: Aruanã , Estado de Goiás, Brazil [about 15°00’S 51°00’ W]; holotype: MZUSP 38511).

Material examined. Brazil: Estado de Goiás: rio Araguaia basin: MZUSP 38511 (male holotype, 28.1 mm SL); MZUSP 38510 (1 paratype [c&s]); MZUSP 38509 (1 paratype [c&s]); MNRJ 11388 (1 paratype), Aruanã ; S. Valério, 1986. UFRJ 6394 (1), swamp close to road GO-173, about 25 km N from Aruanã , 14º49’10.0”S 50º58’36.4”W, altitude 255 m; W. J. E. M. Costa, C. P. Bove, J. Paz & A. Oliveira, 13 Apr. 2006. UFRJ 6395 (1), swamp close to road GO-173, about 5 km S from Aruanã , 14º59’34.7”S 51º05’31.2”W, altitude 265 m; W. J. E. M. Costa, C. P. Bove & J. Paz, 12 Apr. 2006. UFRJ 6396 (3), swamp close to road GO-173, Aruanã , 14º44’38.8”S 50º56’34.8”W, altitude 255 m; W. J. E. M. Costa, C. P. Bove, J. Paz & A. Oliveira, 13 Apr. 2006. UFRJ 3540 (13), temporary pool 4 km E of rio Araguaia, road to Peixe; W. J. E. M. Costa, G. C. Brasil. M. I. Landim & C. Moreira, 16 Feb. 1996. Estado do Tocantins: UFRJ 3563 (27); UFRJ 3564 (4 [c&s]), temporary lagoon near Barreira do Piqui; W. J. E. M. Costa, G. C. Brasil. M. I. Landim & C. Moreira, 15 Feb. 1996. MZUSP 45222 (28), rio Água Fria, Praia Alta 2 farm, road Araguaçu-Barreira do Piqui, 27 km N from Araguaçu; F. C. T. Lima, 21–26 Feb. 1993. UFRJ 5265 (4), ilha do Bananal; D. Almeida & R. D’Arrigo, 20 Feb. 1999. UFRJ 6397 (11), temporary pool in rio Formoso floodplains, road BR-242, 11º47’31.6”S 49º45’54.7”W; W. J. E. M. Costa, C. P. Bove, J. Paz & A. Oliveira, 15 Apr. 2006. Estado do Pará: UFRJ 3934 (9); UFRJ 3935 (3 [c&s]), pool 50 m from rio Araguaia, Vila de Santa Cruz, São Geraldo do Araguaia; C. Moreira & B. Milanez, 16 Jan. 1996.

Diagnosis. Differs from all other congeners by the following combination of characters: 25–29 scales in longitudinal series (vs. 23–24), pectoral fin with vertical rows of small dark gray spots or dark gray bars in males (vs. pectoral fin without dark marks), frontal squamation F-patterned (vs. D-patterned), anterior section of supraorbital series of neuromasts continuous (vs. interrupted), dark marks on flank mainly longitudinally arranged in females (vs. mainly obliquely or irregularly arranged), body depth 21.3–24.6 % SL in males and 18.1–23.8 % SL in females (vs. body depth 24.6–27.2 % SL in males and 24.1–26.3 % SL in females), caudal peduncle depth 15.5–17.1 % SL in males and 14.7–15.7 % SL in females (vs. caudal peduncle depth 17.6– 19.5 % SL in males and 15.6–17.9 % SL in females), head depth 69.4–75.4 % SL in males and 65.2–68.1 % SL in females (vs. head depth 74.9–80.7 % SL in males and 71.8–77.1 % SL in females) and 4–5 bars or transverse rows of spots on pectoral fins in males (vs. 7–8).

Description. Morphometric data appear in Table 1 . Largest male examined 32.6 mm SL; largest female examined 28.0 mm SL. Dorsal profile slightly convex from snout to end of dorsal-fin base, approximately straight on caudal peduncle. Ventral profile weakly convex from lower jaw to anal-fin origin, nearly straight along caudal peduncle. Body slender, subcylindrical, slightly deeper than wide, greatest body depth at level of pelvic-fin base. Jaws short, snout blunt.

Dorsal and anal fins pointed in both sexes, longer and often with filamentous tip reaching to vertical through base of caudal fin in males. Caudal fin rounded. Pectoral fins rounded, its posterior margin reaching vertical between pelvic-fin base and anus in males, through pelvic-fin base in females. Pelvic fin short, slightly pointed in males, elliptical in females; tip of each pelvic fin reaching between base of 1st and 3rd analfin rays in males, and base of 1st anal-fin ray in females. Pelvic-fin bases medially in close proximity. Dorsalfin origin at vertical through base of 10th or 11th anal-fin rays, between neural spines of vertebrae 18 and 20. Anal-fin origin between pleural ribs of vertebrae 12 and 14. Dorsal-fin rays 8–10; anal-fin rays 14–16; caudalfin rays 25–28; pectoral-fin rays 14–15; pelvic-fin rays 7.

Scales large, cycloid. Body and head entirely scaled, except on anteroventral surface of head. No scales on dorsal and anal-fin bases. Scales extending onto anterior 45–50 % of caudal fin. Frontal squamation F-patterned, frontal scales circularly arranged around A-scale without free margins; E-scales not overlapping; row of scales anterior to H-scale; supraorbital scales 5–7. Longitudinal series of scales 26–28; transverse series of scales 7–8; scale rows around caudal peduncle 16. Three to five contact organs on posterior margin of each scale of flank and opercular region. No contact organs on fin rays.

Cephalic neuromasts: supraorbital 5–7 + 4–5, parietal 2, anterior rostral 1, posterior rostral 1, infraorbital 1 + 1 + 17 + 1, preorbital 4–5, otic 1, post-otic 2, supratemporal 1, median opercular 1, ventral opercular 3, preopercular 10, mandibular 9–11, lateral mandibular 3–4, paramandibular 1. One neuromast per scale of lateral line. Two neuromasts on caudal-fin base.

Basihyal subtriangular, greatest width about 55 % of length; basihyal cartilage about 30 % of total length of basihyal. Six branchiostegal rays. Second pharyngobranchial teeth 2–3. Gill-rakers on first branchial arch 1 + 9. Vomerine teeth 1–2. Dermosphenotic present. Ventral process of posttemporal vestigial or absent. Total vertebrae 28–29.

Coloration. Males. Sides of body dark brown to purplish brown, with oblique rows of small metallic blue to golden spots; dark metallic blue blotch on humeral region. Dorsum light brown. Venter light gray. Sides of head light blue to greenish golden, scale borders brown; dark gray to black infraorbital bar, adjacent to narrow preorbital light bluish gray bar. Jaws dark brown. Iris yellow, with dark brown bar through center of eye. Exposed part of branchiostegal membrane dark gray. Dorsal fin bright blue, distal portion of median rays red, posterior portion of fin yellow with 4–5 short brown bars. Anal fin dark brown, reddish brown on distal portion, dark gray on distal margin; row of 6–7 yellow spots along fin base and posterior margin; sometimes one or two transverse rows of pale blue or pale yellow spots on subdistal region. Caudal fin dark purplish brown, sometimes with transverse row of pale small blue spots. Pectoral fins light blue, with 4–5 transverse rows of dark gray to black spots, usually coalesced to form bars. Pelvic fins orangish brown with pale yellow spots on basal portion.

Females. Sides of head and trunk light gray with small brown spots, mostly horizontally arranged, often coalesced to form stripes with oblique extensions. Dorsum light brown. Venter light gray. Opercular region pale greenish golden. Dark gray infraorbital bar, adjacent to narrow preorbital light gray bar. Jaws brown. Iris yellow, with dark brown bar through center of eye. Unpaired fins hyaline, with faint small brown spots on basal portion. Paired fins hyaline.

Distribution and habitat. Temporary swamps of middle rio Araguaia basin, Goiás and Tocantins, Brazil ( Fig. 1 ), usually in open areas of savanna vegetation.

Figures

FIGURE 1. Geographic distribution of the genus Pituna. Triangle = P. schindleri; inverted triangle = P. xinguensis; star = P. brevirostrata; dots = P. poranga; square = P. c o m p a c t a; asterisk = P. obliquoseriata. One symbol may represent more than one collecting site.

FIGURE 4. Pituna poranga, UFRJ 6394, male, 30.3 mm SL (some hours after collection); Brazil: Goiás: Aruanã. Photo by W. J. E. M. Costa.

FIGURE 5. Pituna poranga, UFRJ 6395, female, 28.0 mm SL (some hours after collection); Brazil: Goiás: Aruanã. Photo by W. J. E. M. Costa.