Maratecoara splendida, 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 : 36-38

Maratecoara splendida , new species

( Figs. 27–28 )

Material examined. Holotype. UFRJ 6431 (male, 27.8 mm SL); Brazil: Estado do Tocantins: temporary lagoon pool in left rio Canabrava floodplains, rio Santa Tereza drainage, rio Tocantins basin, road TO-373, between Alvorada and Peixe, 12º29’46.3”S, 49º0’50.7”W, altitude 292 m; W. J. E. M. Costa, C. P. Bove, J. Paz & A. Oliveira, 16 April 2006.

Paratypes. Brazil: Estado do Tocantins: rio Tocantins basin: UFRJ 6432 (4 males, 24.6–31.9 mm SL, 5 females, 22.9–25.1 mm SL); UFRJ 6433 (2 males, 28.1–30.0 mm SL, 2 females, 21.7–23.2 mm SL); MCP 40501 (1 male, 27.7 mm SL, 1 female, 24.2 mm SL); collected with holotype.

Diagnosis. Distinguished from all other species of Maratecoara in having a distinct color pattern, consisting of conspicuous orange spots on basal half of anal fin and flank region adjacent to anal fin (vs. few pale orange spots, these often absent). Maratecoara splendida is also distinguished from congeners by the following combination of characters: no scales on dorsal and anal-fin bases (vs. body squamation extending onto dorsal and anal-fin bases in males), dorsal profile of head straight to slightly concave in adult males (vs. strongly concave), basal half of caudal fin with orange stripes parallel to fin rays in males (vs. vertical rows of orange spots), anteroventral portion of flank with three or four oblique orange bars (vs. broad orange blotch just posterior to pectoral-fin insertion), and no distinctive bright blue zone on distal portion of anal fin (vs. broad bright blue zone in males).

Description. Morphometric data appear in Table 3 . Largest male examined 31.9 mm SL, largest female examined 25.1 mm SL. Dorsal profile straight to gently concave on head, convex from nape to end of dorsalfin base, nearly straight on caudal peduncle. Ventral profile weakly 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. Jaws short, snout slightly pointed.

Dorsal and anal fin long in males, pointed, terminating in long filamentous rays, tips surpassing posterior margin of caudal fin; dorsal and anal fins slightly pointed and short in females. Caudal fin lanceolate in males, with filamentous rays on posterior tip of fin; caudal fin rounded in females. Pectoral fins elliptical, posterior margin reaching vertical between base of 4th and 6th anal-fin rays in males, between urogenital papilla and anal-fin origin in females. Pelvic fins elliptical, without filaments; tip of each pelvic fin reaching between base of 4th and 6th anal-fin rays in males, reaching to base of 2nd anal-fin ray in females. Pelvic-fin bases in close proximity medially. Dorsal-fin origin on vertical between base of 3rd and 5th anal-fin rays, and between neural spines of 12th and 13th vertebrae. Anal-fin origin between pleural ribs of 10th and 12th vertebrae. Dorsalfin rays 11–13; anal-fin rays 15–17; caudal-fin rays 25–27; pectoral-fin rays 13; pelvic-fin rays 8.

Scales large, cycloid. Body and head entirely scaled, except anterior ventral surface of head. Body scales extending over anterior 25 % of caudal fin; no scales on dorsal and anal-fin bases. Frontal squamation F-patterned; E-scales not overlapping medially; scales arranged in regular transverse pattern. No scale anterior to H-scale. Four to five supraorbital scales. Longitudinal series of scales 24–26; transverse series of scales 9; scale rows around caudal peduncle 16. Three to five contact organs on posterior margin of each scale of ventral portion of flank in males.

Cephalic neuromasts: supraorbital 6–8 + 3–4, parietal 3, anterior rostral 1, posterior rostral 1, infraorbital 1 + 20–22 + 1, preorbital 4–5, otic 1, post-otic 2, supratemporal 1, median opercular 1, ventral opercular 1–2, preopercular 13–14, mandibular 7–10, lateral mandibular 5. One neuromast on center of each scale of lateral line of trunk. Two neuromasts on caudal-fin base.

Basihyal narrow, longest width about 45 % of length; basihyal cartilage about 30 % of basihyal length. Six branchiostegal rays. Four teeth on second pharyngobranchial. Gill-rakers of first branchial arch 1 + 6. One vomerine tooth. Ventral process of posttemporal absent. Total vertebrae 27.

Coloration. Males: Sides of body metallic blue to purplish blue above anal fin, with small orange spots arranged in three horizontal rows on anterodorsal portion of flanks, three horizontal rows on caudal peduncle narrow, and three or four bars on anteroventral portion of flank. Dorsum light brown. Venter white. Sides of head metallic blue, with small orange spots; black infraorbital bar and triangular, dark brown supraorbital bar. Jaws orange. Iris bright green, with black bar through center of eye. Dorsal fin metallic blue, with transverse rows of orange spots or transverse stripes on basal half of fin, distal portion of rays red, filaments dark brown. Anal fin metallic blue, with round orange spots on basal half of fin and distal portion of rays orange. Caudal fin metallic blue, with orange stripes parallel to fin rays. Pectoral fins hyaline. Pelvic fins metallic blue, with orange spots.

Females: Sides of body light brownish gray, with longitudinal rows of pale brown dots. Dorsum light brownish gray. Venter white. Sides of head and jaws gray, pale greenish yellow or pale blue on opercle; dark gray infraorbital bar. Iris yellow, with gray bar through center of eye. Fins hyaline.

Etymology. From the Latin splendida (splendid), in allusion to the brilliant colors in males of the species.

Distribution and habitat. Maratecoara splendida is known only from the type locality, a seasonal lagoon near rio Canabrava, rio Tocantins basin ( Fig. 22 ), in a savannah region.

Figures

FIGURE 22. Geographic distribution of the genus Maratecoara. dots = M. lacortei; square = M. splendida; lozenge = M. formosa. One symbol may represent more than one collecting site.

FIGURE 27. Maratecoara splendida, male holotype, 27.8 mm SL, UFRJ 6431 (some hours after collection); Brazil: Tocantins: rio Canabrava floodplains. Photo by W. J. E. M. Costa.

FIGURE 28. Maratecoara splendida, female paratype, 24.4 mm SL, UFRJ 6432 (some hours after collection); Brazil: Tocantins: rio Canabrava floodplains. Photo by W. J. E. M. Costa.