Pituna schindleri, Costa, Wilson J. E. M., 2007

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 : 13-16

Pituna schindleri , new species

( Figs. 8–9 )

Material examined. Holotype. UFRJ 6399 (male, 34.5 mm SL); Brazil: Estado do Piauí, road BR-343, 26 km NW from Campo Maior, rio Corrente drainage, rio Parnaíba basin, about 4°30’S, 42°00’W; W. J. E. M. Costa, A. C. Bacellar, F. Pupo & E. Araujo, 10 May 1999.

Paratypes. Brazil: Estado do Piauí, rio Corrente drainage, rio Parnaíba basin: UFRJ 4879 (21 males, 26.2– 36.5 mm SL, 25 females, 23.1–31.4 mm SL); MCP 40497 (3 males, 31.3–33.9 mm SL, 3 females, 27.2–29.8 mm SL); UFRJ 5547 (4 males, 29.1–40.1 mm SL, 4 females, 29.9–32.3 mm SL [c&s]), collected with holotype. UFRJ 5548 (1 female, 44.8 mm SL), temporary lagoon near Campo Maior; temporary lagoon near Campo Maior; same collectors and date as holotype. UFRJ 4592 (3 males, 25.7–32.1 mm SL; 3 females, 22.6–33.0 mm SL), road PI-110, between Barras and Batalha; I. Schindler, 6 April 1994.

Diagnosis. Pituna schindleri differs from all other congeners in having more teeth on the second pharyngobranchial (4–7 vs. 2–3) and more neuromasts in the infraorbital series (1 + 1+ 17–21 + 1 vs. 1 + 1 + 10–17 + 1). Also distinguished from all other species of the genus 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), and dark marks irregularly arranged on flank in females (vs. regularly arranged).

Description. Morphometric data appear in Table 2 . Largest male examined 40.1 mm SL; largest female examined 44.8 mm SL. Dorsal profile slightly convex from snout to end of dorsal-fin base, approximately straight on caudal peduncle. Ventral profile gently 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.

(continued).

Dorsal and anal fins pointed in both sexes, longer and often with filamentous tip reaching to vertical through caudal-fin base in males. Caudal fin rounded. Pectoral fins rounded, the posterior margin reaching vertical between pelvic-fin base and anus in males, and through pelvic-fin base in females. Pelvic fins short, slightly pointed in males, elliptical in females; tip of each pelvic fin reaching between base of 2nd and 3rd analfin rays in males, and base of 1st anal-fin ray in females. Pelvic-fin bases in close proximity medially. Dorsalfin origin on vertical through base of 9th or 10th anal-fin rays, between neural spines of vertebrae 18 and 20. Anal-fin origin between pleural ribs of vertebrae 12 and 13. Dorsal-fin rays 8–9; anal-fin rays 13–15; caudalfin rays 26–28; pectoral-fin rays 14–15; pelvic-fin rays 7–8.

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 7–8. Longitudinal series of scales 25–26; transverse series of scales 7; scale rows around caudal peduncle 16. Three to five contact organs on posterior margin of each scale of flank. No contact organs on fin rays.

Cephalic neuromasts: supraorbital 5–7 + 4–5, parietal 1–2, anterior rostral 1, posterior rostral 1, infraorbital 1 + 1 + 17–21 + 1, preorbital 5–6, otic 1, post-otic 2, supratemporal 1, median opercular 1, ventral opercular 2, preopercular 8–9, mandibular 9–10, lateral mandibular 3–5, paramandibular 1. One neuromast per scale of lateral line. Two neuromasts on caudal-fin base.

Basihyal subtriangular, greatest width about 60 % of length; basihyal cartilage about 40 % of total length of basihyal. Six branchiostegal rays. Second pharyngobranchial teeth 4–7. Gill-rakers on first branchial arch 1 + 8. Vomerine teeth 2–3. Dermosphenotic present. Ventral process of posttemporal vestigial. Total vertebrae 27–29.

Coloration. Males. Sides of body purplish brown with oblique rows of small greenish golden spots; metallic blue blotch on humeral region. Dorsum light brown. Venter light gray. Sides of head light greenish golden, scale borders purplish brown; dark gray to black infraorbital bar, adjacent to narrow preorbital light gray bar. Jaws purplish brown. Iris orangish yellow, with dark brown bar through center of eye. Exposed parts of branchiostegal membranes dark gray. Dorsal fin bright greenish blue, distal portion of median rays red, posterior portion of fin yellow with 4–5 short brown bars. Anal fin dark brown, orangish brown on distal portion; row of 7–8 yellow spots along fin base and posterior margin; sometimes one or two transverse rows of pale yellow on subdistal region. Caudal fin dark purplish brown with transverse rows of small pale blue spots. Pectoral fins light blue, with 5–7 transverse rows of dark gray to black spots. Pelvic fins orangish brown, with pale yellow spots on basal portion.

Females. Sides of head and trunk light gray, with dark brown dots irregularly arranged or scarcely arranged in oblique rows. Dorsum light brown. Venter light gray. Opercular region pale greenish golden. Dark gray infraorbital bar, adjacent to narrow preorbital light gray bar. Jaws gray. Iris yellow, with dark brown bar through center of eye. Unpaired fins hyaline, with faint small brown spots on basal portion. Paired fins hyaline.

Etymology. Named in honor of Ingo Schindler, the first collector of the species.

Distribution and habitat. Seasonal pools in the lower rio Parnaíba basin, northeastern Brazil ( Fig. 1 ), in savannah area.

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 8. Pituna schindleri, UFRJ 6398, male holotype, 34.5 mm SL (one day after collection); Brazil: Piauí: rio Corrente drainage. Photo by W. J. E. M. Costa.

FIGURE 9. Pituna schindleri, UFRJ 4879, female paratype, 29.4 mm SL (one day after collection); Brazil: Piauí: rio Corrente drainage. Photo by W. J. E. M. Costa.

Tables

TABLE 2. Morphometric data for four new species of the genus Plesiolebias.

	P. fragilis		P. altamira
	males (n = 5)	females (n = 5)	males (n = 2)	females (n = 2)
Standard length (mm)	14.0–19.7	15.0–20.2	17.1–17.5	16.6–18.1
Percentages of standard length
Body depth	23.2–25.4	22.6–25.7	24.8–25.6	23.0–26.0
Caudal peduncle depth	12.0–14.9	11.9–14.0	14.1–14.5	13.1–13.9
Pre-dorsal length	55.6–57.3	57.5–60.0	59.5–61.7	62.5–63.5
Pre-pelvic length	44.2–48.2	46.7–49.2	45.0–46.4	46.3–46.9
Length of dorsal-fin base	12.3–15.8	11.3–14.3	16.1–16.8	16.5
Length of anal-fin base	19.7–23.0	17.8–20.4	23.2–24.9	20.6–21.1
Caudal-fin length	37.8–44.0	36.1–38.6	40.2–42.0	44.9–46.0
Pectoral-fin length	18.9–23.6	20.9–21.1	22.0–25.6	20.9–22.3
Pelvic-fin length	18.6–25.7	12.3–14.4	26.8–29.3	12.8–15.4
Head length	28.1–33.8	27.3–29.8	30.1–31.0	28.2–29.4
Percentages of head length
Head depth	64.9–74.0	67.6–77.1	74.3–75.1	71.6–76.3
Head width	54.5–57.0	57.2–59.0	62.5–63.9	63.3–65.4
Snout length	13.3–16.2	12.9–14.9	13.3–14.2	14.7–14.9
Lower jaw length	11.8–13.3	11.0–14.0	14.4–15.1	13.2–13.4
Eye diameter	39.2–41.9	38.6–41.4	40.3–41.1	40.9–45.1