Leporinus tigrinus Borodin, 1929

Boaretto, Mariana Pascoal, Souza-Shibatta, Lenice & Birindelli, José L. O., 2024, A systematic assessment of Leporinus tigrinus (Characiformes: Anostomidae) using morphological and molecular data, Zootaxa 5432 (4), pp. 535-554 : 541-545

Leporinus tigrinus Borodin, 1929

( Figs. 3–4 )

Leporinus fasciatus tigrinus Borodin, 1929: 280 (original description; type locality: "Goyaz, Brazil ”; 2 syntypes, MCZ 20446).— Britski & Garavello, 1978: 244 (cited, type locality). Leporinus tigrinus .— Garavello, 1979: 66, 391, pl. 2 (fig. 8) (unpublished PhD thesis, redescription).— Santos & Jégu, 1989: 171–172, 179, 186, 195, 207 (short description, photo; lower rio Tocantins basin, Pará, Brazil).— Mahnert et al., 1997: 842 (cited, Tocantins-Araguaia basin).— Britski, 1997: 37, 41 (cited, Tocantins-Araguaia basin).— Géry, 1999: 110 (discussion on color pattern).— Zuanon, 1999: 92, 98–99, 101, 103, 111, 124, 126 (unpublished PhD thesis, discussion of habitat and ecology at rio Xingu).— Garavello & Britski, 2003: 79 (listed, rio Tocantins basin).— Camargo et al., 2004:132 (listed, middle and lower rio Xingu basin).— Langeani et al., 2007:184 (listed, Upper rio Paraná basin basin, Brazil).— Lucinda et al., 2007: 75 (listed, middle rio Tocantins basin, Tocantins state, Brazil).— Pavanelli et al., 2007: 60 (listed, rio Corumbá, upper rio Paraná basin basin, Goiás state, Brazil).— Sidlauskas & Vari 2008: 85–86, 99, 102–105, 108, 127, 131, 134, 143, 147, 150, 152–153, 162, 179 (phylogenetic relationships; rio Tocantins basin, Brazil).— Santos et al., 2013: 1543–1544 (Upper rio Paraná basin).— Birindelli & Britski, 2013: 33 (comparative material, rio Teles Pires basin, Brazil).— Giarrizzo et al., 2015: 2 (length-weight relationship, rio Xingu basin, Pará state, Brazil).— Ramirez et al., 2016: 4–5 (fig. 1o) (phylogenetic relationships based on molecular data;rio Araguaia, Brazil).— Britski & Birindelli, 2016: 26–27, 39 (comparative material, Tocantins, Xingu and Tapajós basins, Brazil).— Ohara et al., 2017: 96 (short description, photo, diagnosis in key: rio Teles Pires, Mato Grosso and Pará states, Brazil).— Burns et al., 2017: 2, 21 (comparative material, Tocantins, Xingu and Tapajós basins, Brazil).— Froehlich et al., 2017: 4 (listed, upper rio Paraná basin, Mato Grosso do Sul state, Brazil).—Ramirez, Birindelli & Galetti Jr., 2017: 310 (comparative molecular material, rio Araguaia, Brazil).— Reis et al., 2020: 457, 485 (listed, upper Paraná basin, Paraná state, Brazil).— Cavaretto et al., 2020: 497–509 (discussion about its occurrence at the upper rio Paraná basin, Brazil).— Ramirez et al., 2020: 7 (comparative molecular material, rio Araguaia, Brazil).

Diagnosis. Leporinus tigrinus is distinguished from all other anostomids, except L. affinis , L. altipinnis , L. bleheri , L. desmotes , L. enyae , L. fasciatus , L. jatuncochi , L. pearsoni , L. villasboasorum and L. yophorus , by having dark vertical bars encircling the body in adults (vs. horizontal bars, when present, not encircling the body – a condition present only in L. octofasciatus among the remaining congeners) and nine branched pelvic-fin rays (vs. eight branched pelvic-fin rays). Leporinus tigrinus is distinguished from the aforementioned species except L. bleheri by having three teeth on the premaxillary and four on the dentary (vs. four teeth on each premaxilla and dentary in L. affinis , L. altipinnis , L. fasciatus , L. pearsoni , and L. yophorus , and three teeth on each premaxillary and dentary in L. desmotes , L. enyae , L. jatuncochi , and L. villasboasorum ). Leporinus tigrinus can be further distinguished from the aforementioned species, except L. pearsoni , by having eight dark transversal bars on the trunk, “X” or “Y” shaped (vs. seven or nine “X” and “Y” shaped bars in L. bleheri , L. desmotes , L. enyae , L. jatuncochi , L. villasboasorum and L. yophorus , and eight to fourteen “I” shaped bars in L. affinis , L. altipinnis and L. fasciatus ).

Description. Morphometric and meristic values in Table 1 . Small sized species for the genus, largest examined specimen 180.3 mm SL. Greatest body depth at dorsal-fin origin. Body somewhat robust. Dorsal profile slightly convex from snout tip to dorsal-fin origin, straight or slightly convex from dorsal-fin to adipose-fin origin, distinctly concave from adipose fin to caudal fin. Ventral profile slightly convex from lower jaw to anal-fin origin, and distinctly concave from anal-fin to caudal-fin. Head and trunk compressed, mouth terminal, snout truncated. Three teeth on premaxillary and four teeth on dentary; teeth stair-like, unicuspid, with straight incisiform margins.

Lateral line complete, extending from supracleithrum to base of caudal-fin rays. Dorsal-fin origin slightly anterior to middle of body, margin slightly convex. Adipose fin small and rounded, its origin approximately at half of anal-fin base. Pectoral-fin origin immediately posterior to vertical through posterior border of opercle, margin distinctly convex. Pelvic-fin origin approximately in the middle of body, distal margin rounded. Anal-fin origin in front of adipose-fin origin by two to four scales, anterior margin straight, with rounded corner, and distal margin straight or slightly concave. Caudal fin forked, with dorsal lobe slightly longer.

Osteology. Infraorbital series composed of six infraorbitals, nasal, antorbital and supraorbital, plate-like. Antorbital longer than infraorbital 1, with no canals. Nasal large, and supraorbital smaller than nasal, also without canals. Second infraorbital with a canal, smaller than third infraorbital, that forms a large portion of ventral margin of the orbit. Fourth and fifth infraorbitals fused, canal with two pores. Sixth infraorbital similar in size with the first, canal with two pores ( Fig. 5C ).

Premaxillary bone trapezoidal, with three unicuspid incisiform teeth, decreasing gradually in size.Maxillary bone arranged vertically to premaxillary, with dorsal portion wider than ventral. Dentary with four unicuspid incisiform teeth, decreasing gradually in size, with the fourth half the size of the third ( Fig. 5B ). Suspensorium L-shaped. Autopalatine rounded. Ectopterygoid long with protuberance on anterior margin. Endopterygoid small, associated to quadrate, which is larger with lateral bony projection relative to most suspensorium bones. Metapterygoid large and triangular. Sympletic long and thin. Hyomandibular large and rectangular, with triangular protuberance on anteroventral margin. Preopercle large, overlapped by hyomandibular and overlapping interopercle. Opercular large, posterior margin rounded, overlapping subopercle ( Fig. 5A ).

Mesethmoid forming the anterior border of the cranium fontanel. Frontal large, rectangular-shaped. Ethmoid long with a distinct lateral process. Parietals wide, sphenotic somewhat triangular, pterotic on the posterolateral border with distinct process. Supraoccipital somewhat rectangular, forming the posterior border of cranial fontanel. Epiotic forming a hole on the posterior border of neurocranium. Vomer triangular in ventral view. Parasphenoid long and thin. Orbitosphenoid, pterosphenoid and prootic dorsal to parasphenoid, ventral to frontal and forming the ventral wall of the braincase. Exoccipital triangular, basioccipital thin and ventral to exoccipital ( Fig. 6 ). Hyoid arch composed of dorsal and ventral hypohyals, anterior and posterior ceratohyals, urohyal, interhyal and four branchiostegals. Branchiostegals spatuled, anteriormost three articulated to posterior ceratohyal and last one articulated with anterior ceratohyal. Branchial apparatus composed of three basibranchials, basihyal, basihyal plate, five ceratobranchials, four epibranchials, three hypobranchial, three pharyngobranchials. Basihyal elongate and connected to basibranchial 1. Basibranchials 1–3 rod-like and connected by cartilage. Anteriormost four ceratobranchials long and rod-like, with small rakers on anterior and posterior margins, fifth ceratobranchial with rakers only on anterior margin, bearing a tooth plate on posterior margin. Four epibranchials, with the fourth bearing a tooth plate ( Fig. 7 ).

Dorsal fin with 2 unbranched, 10 branched rays and two supraneurals. Pelvic bone supporting 9 branched rays. Anal fin with 2 unbranched and 9 branched rays ( Fig. 8 ). Pectoral fin connected to neurocranium by extrascapular and postemporal with 13 to 15 branched rays. Cleithrum large, somewhat triangular. Coracoid rectangular with triangular posterior process. Two postcleithra present, the first rounded, posterior to cleithrum, the second triangular, posterior to cleithrum and scapula. Pelvic bone with 9 branched rays. Caudal skeleton composed of three epurals, five hypurals, haemal spine, modified neural process, neural spine, cartilage opistural cartilage, parhypural and uroneural. Parhypural and two hypurals on lower lobe, and four hypurals on upper lobe. Neural and haemal spines adjacent to caudal-fin skeleton with anterior bony projections ( Fig. 9 ).

Coloration in life. Live specimens with ground color orange to yellow, sometimes slightly dark, countershaded with abdominal region lighter and dorsal region bright yellow. Dark transversal body bars conspicuously black. Posterior portion of upper lip with a small metallic blue spot, sometimes inconspicuous. Fins grey to yellow, with fins on ventral portion of body lighter ( Fig. 3 ).

Coloration in alcohol. Overall body color light tan, vertical bars dark brown, bifurcated dorsally. Two less prominent vertical bars on the head, eight bars on the trunk. First trunk bar on the operculum and the last at the end of the caudal peduncle, with second to fifth Y-shaped, fourth X-shaped in some individuals. Bars slightly faded in larger specimens. Fins slightly hyaline at the tips, slightly yellow on the rest ( Fig. 4 ).

Distribution. Leporinus tigrinus occurs in the rio Tocantins /Araguaia, rio Xingu and rio Tapajós basins,Amazon basin, Brazil. The species was introduced in the upper rio Paraná basin in Brazil ( Fig. 10 ). The species is commonly found between rocks in shallow rapids ( Zuanon 1999), and near rivers margins ( Ohara et al., 2017).

Material examined. All from Brazil. MCZ 20446 , two syntypes, 138.3–143.9 mm SL “ Goyaz ” (no exact locality; see Lima, 2004),“ Sr. Honorio ”, 1867 . MZUEL 20673 , 9 , 78.9–131.2 mm SL; 1 CS, 97.1 mm SL, Goiás, São Miguel do Araguaia, rio Araguaia at Luiz Alves , 13°16’35”S 50°36’28”W, 15 Oct 2019, J. L. O. Birindelli, N. T. Narezzi, E. Santana, A. Souza . MZUEL 20938 , 1 , 97.7 mm SL, Goiás, São Miguel do Araguaia , irrigation canals near Luiz Alves, 12°12’56”S 50°33’50”W, 16 Oct 2019, J. L. O. Birindelli, N. T. Narezzi, E. Santana, A. Souza . MZUSP 84027 , 7 , 84.8–101.1 mm SL, Tocantins, Conceição do Tocantins, rio Palma at Taipas village , 12°22’08”S 47°03’21”W, 01 Aug 2002, C. R. Moreira, J. C. Nolasco, M. Avila . MZUEL 19890 , 2 , 122.6 – 134.5 mm SL, São Paulo, Brasilândia, rio Verde , 21°02’13.98”S 52°08’45.98”W, 11 Jan 2018, M. Makrakis . MZUEL 19916 , 1, 180.3 mm SL, São Paulo, Brasilândia, rio Verde , 21°02’98”S 52°08’45.98”W, 08 Jun 2016, M. Makrakis . MZUEL 19912 , 1, 136.4 mm SL, Mato Grosso do Sul, Bataguassu, rio Pardo , 21°41’20.72”S 52°28’54”W, 21 Jan 2013, M. Makrakis . MZUEL 19913 , 2 , 146.6 -148.0 mm SL, Mato Grosso do Sul, Bataguassu, rio Pardo , 21°41’20.72”S 52°28’54”W, 25 Apr 2013, M. Makrakis . MZUEL 19915 , 1 , 88.35 mm SL, Mato Grosso do Sul, Bataguassu, rio Pardo , 21°41’20.72”S 52°28’54”W, 16 Jan 2014, M. Makrakis . LIA 1305 , 2 , 83.2 –106.0 mm SL, Pará, São Félix do Xingu, rio Xingu at Pedra Preta, 6°93’39.1”S 52°13’70.7”W, 22 Set 2014, L. Sousa, A. Gonçalves, C. Martins . MZUSP 111213 , 4 , 91.7–113.5 mm SL, Pará, Altamira, rio Xingu at rocky rapid upstream from Altamira , 3°19’30.0”S 52°11’10.0”W, 8 Nov 2011, O. T. Oyakawa, J. L. O. Birindelli, C. R. Moreira, A. Akama , L. M. Sousa, M. A. Varella . MZUSP 99495 , 18 , 80.4–114.6 mm SL, Pará, Jacareacanga, rio Teles Pires at right margin of Jacareacanga, 9º20’24.0”S 56º46’33.0”W, 23 Mar 2008, R. Hilário.

Figures

FIGURE 3. Leporinus tigrinus, syntypes, MCZ 20446, 138.3–143.9 mm SL: “Goyaz”, Brazil.

FIGURE 4. Photographs of living specimens of Leporinus tigrinus from (A) rio Araguaia, Luiz Alves, Goiás (photo by José Birindelli), and (B) rio Xingu, Altamira, Pará (photo by Leandro Sousa).

FIGURE 5. (A) Suspensorium of Leporinus tigrinus (MZUEL 20673, 112.0 mm SL); (B) Premaxilla, maxilla, dentary and anguloarticular; (C) Infraorbital bones.

FIGURE 6. Cranium bones of Leporinus tigrinus (MZUEL 20673, 112.0 mm SL) in (A) dorsal, (B) lateral and (C) ventral view.

FIGURE 7. (A) Hyoid arc and (B and C) branchial apparatus of Leporinus tigrinus (MZUEL 20673, 112.0 mm SL)

FIGURE 8. (A) Dorsal fin and (B) anal fin of Leporinus tigrinus (MZUEL 20673, 112.0 mm SL)

FIGURE 9. (A) Pectoral fin, (B) pelvic fin and (C) caudal fin of Leporinus tigrinus (MZUEL 20673, 112.0 mm SL)

FIGURE 10. Partial map of South America showing the distribution of Leporinus tigrinus based on material examined in the present study.