Leporinus melanopleura Günther, 1864

Birindelli, José L. O., Britski, Heraldo A. & Garavello, Julio C., 2013, Two new species of Leporinus Agassiz (Characiformes: Anostomidae) from eastern basins of Brazil, and redescription of L. melanopleura Günther, Neotropical Ichthyology 11 (1), pp. 9-23 : 10-13

Leporinus melanopleura Günther, 1864 Figs 1 and 2

Leporinus melanopleura Günther, 1864: 310 [in part, lectotype (by present designation) and paralectotype from “ Bahia ”, not paralectotype from rio Cipó; type locality: “ Bahia ” (herein restricted to an indefinite locality within the rio Una drainage, southern Bahia, Brazil)].- Steindachner, 1876: 110 [citation].- Eigenmann & Eigenmann, 1891: 51 [catalog].- Eigenmann, 1910: 426 [catalog].- Fowler, 1950: 238 [catalog].- Géry, 1960: 283 [citation].- Géry, 1977: 167 [identification key].- Garavello & Britski, 2003: 76 [catalog].- Britski & Garavello, 2007: 25 [catalog].

Diagnosis. Leporinus melanopleura is distinguished from all congeners except L. melanopleurodes , by having a single broad dark midlateral stripe on body, encompassing two scale rows of depth and centered on the scale row below lateral line. Leporinus melanopleura is further distinguished from congeners except Leporinus amae Godoy , L. arcus Eigenmann , L. amblyrhynchus Garavello & Britski , L. bistriatus Britski , L. britskii Feitosa, Santos & Birindelli , L. melanopleurodes , L. sexstriatus Britski & Garavello , L. striatus Kner , L. taeniatus , L. taeniofasciatus Britski , L. unitaeniatus Garavello & Santos , and L. vanzoi Britski & Garavello , by the presence of a dark midlateral stripe on body. Leporinus melanopleura is additionally distinguished from Leporinus arcus , L. amblyrhynchus , L. britskii , L. sexstriatus , L. striatus , L. taeniatus , L. taeniofasciatus , L. unitaeniatus and L. vanzoi , by having three scale rows between dorsal-fin origin and lateral line and three or 3.5 scale rows between lateral line and pelvic-fin origin (vs. four or five). Leporinus melanopleura is distinguished from Leporinus amae and L. bistriatus by having a single dark midlateral stripe on body encompassing two scale rows of depth and centered on the scale row below lateral line (vs. a dark midlateral stripe centered on lateral-line scale row, and a second dark stripe on dorsum); and from Leporinus amae by having adipose fin red in life (vs. hyaline). Leporinus melanopleura is distinguished from L. melanopleurodes by having a subinferior mouth (vs. inferior), hyaline (red in life) adipose fin (vs. dark), and an inconspicuous dark blotch on caudal peduncle (vs. conspicuous).

Description. Morphometric data in Table 1. Small size, relative to congeners. Largest examined specimen 104.3 mm SL. Head and body elongate and moderately compressed. Dorsal profile gently convex from snout tip to dorsal-fin origin, somewhat straight along dorsal-fin base, gently convex or straight from terminus of dorsal-fin base to adipose-fin origin, and distinctly concave from adipose-fin origin to base of anteriormost procurrent ray of caudal fin. Ventral profile straight to slightly concave from lower jaw to vertical through posterior margin of opercle, gently convex from latter point to anal-fin origin, somewhat straight along anal-fin base, and concave from terminus of anal-fin base to base of anteriormost procurrent ray of caudal fin. Greatest body depth at dorsal-fin origin.

Mouth subinferior, and longitudinally aligned with ventral margin of infraorbital series, in specimens of 50 mm SL or longer ( Fig. 1 a-c). Mouth terminal in specimens of about 30 mm SL ( Fig. 1d ) and dorsally oriented in specimens of approximately 15 mm SL ( Fig. 1e ). Snout rounded, anteriorly blunt. Premaxilla with three incisiform teeth gradually decreasing in size from the symphyseal tooth. Dentary with four incisiform teeth gradually decreasing in size posterolaterally ( Fig. 3 ).

Scales cycloid, with 6 (1), 7 (2), or 8 (2) radii. Lateral line complete, extending from supracleithrum to base of median caudal-fin rays, with 36 (2), 37 (18), or 38* (22) perforated scales. Longitudinal scale rows between dorsal-fin origin and lateral line 3 (42). Longitudinal scale rows between lateral line and pelvic-fin origin 3 (23) or 3.5* (19). Longitudinal scale rows around caudal peduncle 12 (42). Predorsal scales from tip of supraoccipital spine to dorsal-fin origin 10 (2), 11 (21) or 12* (5).

Dorsal-fin rays ii,9 (3) or ii,10* (26). Dorsal-fin origin slightly anterior to midpoint of standard length and to vertical through pelvic-fin origin; distal margin of dorsal fin gently convex. Adipose fin small, teardrop-shaped with origin approximately at vertical through base of last anal-fin ray. Pectoral-fin rays i,13* (8), i,14 (18), i,15 (2), or i,16 (1); tip of adpressed pectoral fin extending to midpoint between origins of pectoral and pelvic fins; distal margin of pelvic fin rounded. Pelvic-fin rays i,8 (29); distal margin of pelvic fin slightly convex. Anal-fin rays ii,8 (29).Anal-fin origin approximately at vertical through posterior margin of fourth scale anterior to adipose-fin origin; adpressed anal fin not reaching base of caudal-fin rays; distal margin of anal fin straight overall or slightly convex. Principal caudal-fin rays i,8,9,i (29). Caudal fin forked, lobes rounded, upper lobe slightly longer than lower lobe. Vertebrae 36 (4), 37 (1), or 38 (3).

Color in alcohol. Ground color brown or tan, weakly countershaded. Head and body with conspicuous dark midlateral stripe extending from immediately above posterior nares to end of caudal peduncle. Stripe broad, encompassing two scale rows of depth, and centered on scale row below lateral line, occupying one-half of lateral-line scale row, all of row below it and one-half of adjacent ventral row. Ventral surfaces of head and body pale to cream. Fins generally hyaline, dorsal and caudal fins slightly darkened. Small specimens (up to 20 mm SL) with dark midlateral stripe on head from lower jaw to opercle, dark stripe from posterodorsal portion of eye to supraoccipital spine, eight irregular dark transverse bars forming fragmented midlateral stripe on body, and dark conspicuous spot on base of median caudal-fin rays ( Fig. 1e ).

Color in life. Life coloration similar to that in preserved specimens with addition of bright red spot on clear area of adipose fin, and red pigmentation on dorsal and distalmost portion of upper lip ( Fig. 2 ).

Distribution. Leporinus melanopleura is apparently endemic of the rio Una, a small coastal river in southern Bahia, Brazil ( Fig. 4 ). The precise collection site of the lectotype of Leporinus melanopleura is unknown; however, because of that species has been collected only in rio Una, that basin is likely the type locality.According to Lima (2001), the Wucherer fishes studied by Günther (1864) apparently originated at localities around Salvador and near the cities of Nazaré, Canavieiras and Ilhéus, in Bahia. The fact that the rio Una is located between Ilhéus and Canavieiras, strengthens the probability that the type locality of Leporinus melanopleura is in that basin.

Remarks. Günther (1864) described Leporinus melanopleura based on three specimens, two of them (BMNH 1863.3.27.6-7) collected by Wucherer in “ Bahia ”, and the other (BMNH 1861.5.16.14) collected by Cumberland in the rio Cipó, a tributary of the rio das Velhas, in the rio São Francisco basin, Minas Gerais. We, herein, designate one of the specimens collected in “ Bahia ” as the lectotype, recognizing this species as possibly endemic to the rio Una, in southern Bahia ( Fig. 4 ). Cumberland’s specimen consists only on the left side of a specimen cut along the sagittal plane and preserved as a dry skin glued to a paperboard ( Fig. 5a ). The specimen collected from rio Cipó does not belong to L. melanopleura since it has 35 lateral-line scales (vs. 36 to 38 in L. melanopleura ), four scales between the dorsal-fin origin and the lateral line (vs. three) and four scales between the lateral line and the pelvic-fin origin (vs. three or 3.5), and a dark midlateral stripe centered on the lateral-line scale row (vs. a midlateral stripe centered on the scale row below the lateral line). The rio Cipó specimen fits the diagnosis of Leporinus taeniatus ( Fig. 5b ), a species widely distributed in the rio São Francisco, rio Parnaíba and smaller drainages in northeastern Brazil. Leporinus taeniatus is diagnosed by having a dark midlateral stripe centered on the lateral-line scale row, dark bars on the dorsum, three teeth on the premaxilla, four on the dentary, 35 to 38 scales in the lateral line and four or five scale rows above and below the lateral line. The only difference between the paralectotype in question and most examined specimens of Leporinus taeniatus is the number of scale rows around caudal peduncle (12 in the paralectotype vs. 16). Nevertheless, some specimens of L. taeniatus have 12 irregular scale rows around caudal peduncle, indicating that this feature may vary in L. taeniatus , and that the paralectotype of L. melanopleura from rio Cipó is Leporinus taeniatus .

Various papers report specimens identified as Leporinus melanopleura . Most of those papers are likely citations of Leporinus taeniatus from the rio São Francisco and rivers of northeast Brazil ( Fowler, 1941: fig. 88, 1950: fig. 276; Britski et al., 1988; Petrere, 1989), and of L. striatus from the río Orinoco basin in Colombia and Venezuela ( Lasso et al., 2004; Maldonado-Ocampo et al., 2008; Lasso et al., 2009; Gama, 2011). Although we did not examine all specimens reported on those papers, due to the restricted distribution of Leporinus melanopleura , we judge those citations to be erroneous.

Material Examined. Brazil. ANSP 173829 , 6 , 29.2 -37.0 mm SL ; MCP 17712 , 1 , 18.4 mm SL ; MCP 17872 , 4 , 37.0- 54.8 mm SL ; MZUSP 100986 , 5 , 34.5-87.1 mm SL, 1 CS, 57.6 mm SL, Bahia, Camacã, rio Branco, tributary of rio Una , on road BR-101, near São João da Capelinha , 15°15’16”S 39°27’7”W . BMNH 1863.3 .27.6 91.2 mm SL, Bahia, lectotype of Leporinus melanopleura Günther, 1864 , by present designation . BMNH 1863.3 .27.7, 1, 104.3 mm SL, Bahia, paralectotype of Leporinus melanopleura Günther, 1864 . MCP 17708 , 1 , 85.5 mm SL, Bahia, Arataca, rio Branco, on road between road BR-101 and Una , approximately 3 km from BR-101, 15°15’11”S 39°26’37”W . MZUSP 111246 , 10 , 27.3-90.9 mm SL, Bahia, São José da Vitória, tributary of rio Una , 15°5’52.4”S 39°21’10.4”W . MZUSP 111601 , 2 , 97.5 and 98.6 mm SL, Bahia, Arataca, rio Aliança , 15°15’3.6”S 39°26’36.6”W . UFBA 4282 , 19 , 69.0- 97.8 mm SL, Bahia, Arataca, rio Aliança , 15°15’28”S 39°25’22”W . UFBA 5103 , 8 , 33.1 -69.0 mm SL, Bahia, São José da Vitória, rio Una , at BR-101 . UFPB 1695 , 22 , 31.9-98.8 mm SL ; USNM 300676 , 8 , 47.8-98.2 mm SL, Bahia, Una, ribeirão das Caveiras, tributary of rio Una , 8 km from São José .

Figures

Fig. 1. Leporinus melanopleura: (a) lectotype, BMNH 1863.3.27.6, 91.2 mm SL, “Bahia”; (b) paralectotype, BMNH 1863.3.27.7, 104.3 mm SL, “Bahia”; (c) MZUSP 111246, 90.9 mm SL, rioUna; (d)MZUSP 111246, 27.3 mm SL, rio Una; (e) MCP 17712, 18.4 mm SL, rio Branco, tributary of rio Una. Scale bars = 10 mm.

Fig. 2. Leporinus melanopleura: (a) MZUSP 111246, 27.3 mm SL, rio Una, (b) MZUSP 111246, 90.9 mm SL, rio Una; both photographed live. Scale bars = 10 mm.

Fig. 3. Scanning electron image of the upper and lower jaws of Leporinus melanopleura in lateral view, MZUSP 100986, 57.6mmSL.

Fig. 4. Distribution of Leporinus melanopleura (triangles), L. melanopleurodes (square), and L. brinco (circles); type localities indicates by white symbols. River basins: (1) rio Jequitinhonha, (2) rio Pardo, (3) rio Una, (4) rio de Contas, (5) rio das Almas, (6) rio Jiquiriçá, (7) rio Paraguaçu, (8) rio Itapecuru, and (9) rio São Francisco.

Fig. 5. Leporinus taeniatus: (a) paralectotype of Leporinus melanopleura, BMNH 1861.5.16.14, 102.6 mm SL, rio Cipó, tributary of rio das Velhas, rio São Francisco basin; (b) MZUSP 47459, 96.5 mm SL, rio Verde, tributary of rio São Francisco. Scale bars = 10 mm.