Received: 7 November 2018 Accepted: 19 March 2019 DOI: 10.1111/jfb.13972 FISH REGULAR PAPER Hemiodus bimaculatus, a new species of Hemiodontidae from the Rio Tapajós drainage, Brazil (Ostariophysi: Characiformes) Acácio F. Nogueira1 | Francisco Langeani2 | André L. Netto-Ferreira3 1 Programa de Pós-Graduação em Zoologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil 2 Laboratório de Ictiologia, Departamento de Zoologia e Botânica, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista (UNESP), São Jose do Rio Preto, Brazil 3 Laboratório de Ictiologia, Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil Correspondence Acácio F. Nogueira, Programa de PósGraduação em Zoologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Corrêa, 01, Guamá, 66075-110, Belém, Brazil. Email: acacio.freitas89@gmail.com Funding information This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brazil (CAPES)–finance code 001 (to AFN). Francisco Langeani receives financial support by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). Hemiodus bimaculatus sp. nov., is described from tributaries of the Rio Juruena and Rio Teles Pires in the upper Rio Tapajós basin. The new species is diagnosed from most congeners, except Hemiodus jatuarana, by having a conspicuous circular or horizontally elongate dark blotch on the caudal peduncle (v. inconspicuous in H. iratapuru and absent in the other species). The new species differs from H. jatuarana by having a round midlateral spot on the flank (v. absent in H. jatuarana), 98–121 perforated scales in the lateral line (v. 66–72 in H. jatuarana), 23–28 scale series above and 14–19 below lateral line (v. 12–13 above and 6–7 below in H. jatuarana). Hemiodus bimaculatus is hypothesised to be related to species of the H. microlepis group, from which it also differs by having 11–25 epibranchial (v. 26–34 in H. argenteus, 29–39 in H. microlepis, 21–42 in H. orthonops and 27–35 in H. parnaguae) and 18–31 ceratobranchial (v. 38–50 in H. argenteus, 43–58 in H. microlepis, 32–52 in H. orthonops and 34–48 in H. parnaguae) gill rakers in the first arch. KEYWORDS Amazon basin, biodiversity, Neotropical fishes, South America, taxonomy 1 | I N T RO D U C T I O N preopercle of Hemiodus has a small, ventrally angled depression that receives the posteroventral portion of the hyomandibular, the only Hemiodus Müller 1842 is the largest genus of the family synapomorphic character for the genus (Langeani, 1998). Hemiodontidae with 21 species (Fricke et al., 2018) and comprises Géry (1977) proposed a species group of Hemiodus based on the small to medium-sized fishes (70–300 mm LS) with fusiform, stream- presence of 80–130 lateral line scales and the presence of a round lined bodies (Langeani, 2003). They are distributed across cis-Andean spot on the flanks, which he called H. microlepis-group (Hemiodus par- South America in lakes and rivers of most drainages, including the naguae Eigenmann & Henn 1916, Hemiodus microlepis Kner 1859 and Amazonas, Orinoco, Tocantins and Paraná-Paraguay Basins, the Hemiodus argenteus Pellegrin 1909). Later, Langeani (1996), in the coastal rivers of the Brazilian and Guiana Shields (i.e., Araguari, Amapá, absence of an interspecific phylogenetic hypothesis for Hemiodus, Itapecuru, Mearim and Parnaíba Rivers), but absent in the Rio São divided the genus into two species groups based on the colour pattern Francisco and most eastern coastal drainages of Brazil (Langeani, of the body and scale counts: (a) species having only one round mid- 2003). Species of Hemiodus can be easily distinguished from all other lateral spot, plus a short dark stripe along the lower lobe of the caudal Hemiodontidae by the presence of multicuspid teeth in the upper jaw fin with an occasionally inconspicuous longitudinal dark stripe starting and the edentulous lower jaw. Also, the mesial surface of the from the midlateral spot up to the caudal stripe and generally with J Fish Biol. 2019;1–6. wileyonlinelibrary.com/journal/jfb © 2019 The Fisheries Society of the British Isles 1 2 NOGUEIRA ET AL. FISH more than 80 perforated scales in the lateral line (equivalent to the H. microlepis species group of Géry, 1977, with the inclusion of Hemiodus orthonops Eigenmann & Kennedy 1903), and (b) species with variable body colour, some having the same pattern described in (a) whereas others differing from it, but all with usually less than 80 perforated scales in the lateral line. A review of hemiodontid specimens in scientific collections yielded specimens of an undescribed species of Hemiodus from the tributaries of the Rio Juruena and the Rio Teles Pires, pertaining to the H. microlepis group, which is described herein. 2 | MATERIALS AND METHODS Hemiodus bimaculatus sp. nov., holotype, MCP 30410,  117.29 mm standard length, Rio Claro or Rio Agua Verde a tributary to Rio Juruena, Amazon basin FIGURE 1 3.1.2 | Paratypes All from Brazil, Mato Grosso: DZSJRP 21442, 8, 63.8–96.8 mm LS, Morphometric and meristic data followed Langeani (1999) and were Juína, marginal flooding of Rio Juruena, 11
320 0700 S, 58
430 0200 W, taken from the left side of the specimens whenever possible. Counts G.L. Brejão et al., 31 May 2018; DZSJRP 21443, 13, 61.2–73.5 mm LS, also included circumpeduncular (around caudal peduncle) and post- District of Fontanillas, Juína, Rio Juruena left bank, 11
200 2500 S, 58
dorsal (between dorsal and adipose fins) scales and gill rakers on first 200 1100 W, G.L. Brejão et al., 13 Jun 2018; DZSJRP 21446, epibranchial and ceratobranchial. Measurements were made with a 4, 61.1–78.2 mm LS, District of Fontanillas, Juína, Rio Juruena left digital calliper and expressed as percentage of standard length (LS) or bank, 11
200 2500 S, 58
200 1100 W, G.L. Brejão et al., 3 Jun 2018; head length (LH). For counts, the number in parentheses indicates the MCP 54129, 11, 47.3–121.3 mm LS, collected with the holotype; frequency of each value and asterisks indicate the values of the holo- MCP 30413, 1, 102.0 mm LS, Tapurah, creek on the road MT-338, c. type. Three paratypes were cleared and stained (c&s) according to 46 km north of Tapurah, 12
230 1400 S, 56
410 5400 W, R.E. Reis, Taylor & Van Dyke (1985) to count vertebrae, branchiostegal rays, L.R. Malabarba & E.H. Pereira, 19 Jan 2002; MCP 30415, 14 of tooth cusps, premaxillary and maxillary teeth. The osteological termi- 46 (3 c&s), 47.8–64.5 mm LS, Nova Guarita, Rio Braço Norte on road nology followed Roberts (1974) with the vertebrae of the Weberian MT-208 between Nova Guarita and the ferry boat of the Rio Teles apparatus counted as four precaudal elements and the fused PU1+U1 Pires, 10
130 4400 S, 55
270 5600 W, R.E. Reis, L.R. Malabarba & as a single caudal element. Institutional abbreviations follow Sabaj E.H. Pereira, 23 Jan 2002; MCP 30424, 1, 77.2 mm LS, Porto dos (2016): CPUFMT, Coleção de Peixes da Universidade Federal de Mato Gaúchos, Rio Chandless on road MT-338, c. 50 km SE of Porto dos Grosso, Cuiabá, Mato Grosso, Brazil; DZSJRP, Departamento de Gaúchos and 168 km N of Tapurah, 11
430 0700 S, 57
010 3100 W, Zoologia e Botânica, Universidade Estadual Paulista Júlio de Mesquita L.R. Malabarba, V.A. Bertaco & A.R. Cardoso, 19 Jan 2002; INPA Filho (UNESP), Campus de São José do Rio Preto, São Paulo, Brazil; 58180, 2, 55.3–62.0 mm LS, same data as MCP 30415; MZUSP INPA, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazo- 124063, 4, 55.9–60.0 mm LS, same data as MCP 30415. nas, Brazil; LBP, Laboratório de Biologia e Genética de Peixes, Departamento de Morfologia, Universidade Estadual Paulista Júlio de 3.1.3 | Diagnosis Mesquita Filho, Campus de Botucatu, São Paulo, Brazil; MCP, Museu de Ciências e Tecnologia, Pontifícia Universidade Católica do Rio Hemiodus bimaculatus is diagnosed from all congeners, except Hemi- Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; MPEG, Museu odus jatuarana Langeani 2004, by the presence of a conspicuous con- Paraense Emilio Goeldi, Zoologia, Belém, Pará, Brazil; MZUSP, Museu centration of superficial melanophores forming a circular or de Zoologia da Universidade de São Paulo, São Paulo, Brazil; UFRGS, Universidade Federal do Rio Grande do Sul, Departamento de Zoologia, Rio Grande do Sul, Brazil. horizontally-elongate dark blotch on the caudal peduncle (v. inconspicuous blotch in Hemiodus iratapuru Langeani & Moreira 2013 and blotch absent in the other species). The new species differs from H. jatuarana by having a dark, round midlateral spot on the flank, 98–124 perforated scales in the lateral line, 22–28 scales above and 3 | RESULTS 14–19 below lateral line (v. spot absent, 66–72, 12–13 and 6–7 3.1 | Hemiodus bimaculatus, new species distinguished from Hemiodus iratapuru by having 98–124 perforated scales, respectively, in H. jatuarana). Hemiodus bimaculatus is further 3.1.1 | Holotype scales in the lateral line, 22–28 scales above and 14–19 below lateral line (v. 43–46, 8 or 9 and 5 scales, respectively, in H. iratapuru). The MCP 30410 (117.3 mm LS) Brazil, Mato Grosso, São José do Rio Claro, new species differs from Hemiodus unimaculatus (Bloch 1794) and  Rio Claro or Rio Agua Verde, c. 12 km SE of São José do Rio Claro on Hemiodus amazonum (Humboldt 1821) by having scales from above road MT-010 towards Diamantino, 13
300 1200 S, 56
370 0800 W, R. E. and below the lateral line of similar size (v. scales below lateral line Reis, L. R. Malabarba & E. H. Pereira, 17 Jan 2002 Figure 1. larger than those above); from Hemiodus atranalis (Fowler 1940), NOGUEIRA ET AL. Hemiodus goeldii Steindachner 1908, Hemiodus gracilis Günther 1864, H. iratapuru, Hemiodus semitaeniatus Kner 1858, Hemiodus ternetzi T A B L E 1 Morphometric data for holotype and paratypes of Hemiodus bimaculatus sp. nov. (n = 32) Myers 1927, Hemiodus thayeria Böhlke 1955, Hemiodus tocantinensis Langeani 1999, 3 FISH Hemiodus huraulti (Géry 1964), Hemiodus quadrimaculatus Pellegrin 1909, Hemiodus vorderwinckleri (Gery 1964) and Hemiodus sterni (Gery 1964) by having the premaxillary teeth with slightly convex or nearly straight distal border (v. premaxillary teeth with strongly convex or lanceolate border); it differs from H. atranalis, H. goeldii, H. gracilis H. semitaeniatus, H. ternetzi, H. thayeria and H. tocantinensis by the lack of a conspicuous longitudinal stripe (v. conspicuous longitudinal stripe extending from midlateral spot to tip of caudal-fin lower lobe in H. atranalis, H. goeldii, H. gracilis, H. semitaeniatus; or from opercle to tip of caudal-fin lower lobe in H. ternetzi, H. thayeria and H. tocantinensis); it differs from H. huraulti, H. quadrimaculatus, H. vorderwinckleri and H. sterni, by lacking vertical bars on the flank (v. bars present); it differs from Hemiodus langeanii Beltrão & Zuanon 2012 by its shorter body depth (range 19.4%– 27.3% LS, mean 22.55% LS, v. range 27.1%–35.3% LS and mean 32.3% Standard length (LS, mm) Holotype Range Mean 117.3 58.6–121.3 76.0 S.D. Percentages of LS Body depth 27.3 19.4–27.3 22.6 1.9 Snout to dorsal-fin origin 48.4 45.5–50.3 48.1 1.4 Snout to anal-fin origin 81.2 78.3–82.8 80.4 1.2 Snout to pectoral-fin origin 24.1 23.5–28.3 25.8 1.3 Snout to pelvic-fin origin 51.7 50.6–54.8 52.6 1.1 Snout to anus 79.4 76.6–81.5 78.5 1.2 Dorsal-fin origin to hypural joint 56.5 51.0–57.0 54.5 1.7 8.6 7.5–8.8 8.3 0.4 1.0 LS, in H. langeanii). Moreover, the new species differs from all the Caudal-peduncle depth above-mentioned species by having > 90 perforated scales along the Pectoral-fin length 17.0 13.7–17.4 16.0 lateral line. Finally, H. bimaculatus is distinguished from species of the Pelvic-fin length 18.0 16.1–19.4 17.9 0.8 H. microlepis group (i.e., with more than 80 scales on the lateral line) Anal-fin length 9.4 8.7–11.3 9.9 0.7 by having 11–25 epibranchial gillrakers (v. 26–34 in Hemiodus argenteus, 29–39 in Hemiodus microlepis, 21–42 in Hemiodus orthonops and 27–35 in Hemiodus parnaguae) and 18–31 ceratobranchial gillrakers (v. 38–50 in H. argenteus, 43–58 in H. microlepis, 32–52 in H. orthonops and 34–48 in H. parnaguae). Anal-fin base length Dorsal-fin length Head length (LH) 9.2 8.3–10.1 9.2 0.5 22.6 20.5–25.0 23.2 1.1 23.4 22.3–27.4 25.0 1.3 Percentages of LH Eye diameter 27.7 27.7–32.9 29.6 1.4 Snout length 30.9 28.0–34.1 31.1 1.4 3.1.4 | Description Post-orbital length 43.1 36.5–43.5 40.6 1.8 Morphometric data for the holotype and 31 paratypes are shown in Interorbital distance 35.4 29.1–37.3 32.4 2.0 Table 1. Body elongate, fusiform and laterally compressed. Highest body depth at dorsal-fin origin. Head profile pointed anteriorly. Dorsal 22(1), 23(2), 24(4), 25(6), 26(1), 27(1) or 28*(6); scales below lateral profile moderately convex from snout tip to dorsal-fin origin, straight line in transverse series 14(5), 15(4), 16(5), 17*(8), 18(3) or 19(4). or slightly convex from dorsal-fin origin to anteriormost portion of Circumpeduncular scales 25(1), 26(12), 27*(2), 28(1), 29(5) or 30(9); caudal peduncle and concave at caudal peduncle. Ventral profile con- postdorsal scales 30(1), 31*(2), 33(1), 34(1), 35(3), 36(1), 37(2), 38(2), vex from mouth opening to anal-fin terminus, straight from that point 39(2) or 40(3). Cleithrum followed by four or five horizontally elon- to anteriormost portion of caudal peduncle and concave at caudal gated scales forming small elevation above axillary depression into peduncle. which proximal portion of first pectoral ray fits. Mouth subterminal. Lower jaw edentulous and rounded anteriorly Pectoral-fin rays i,16*(11), i,17(10), i,18(12) or i,19(1). Supraneurals in ventral view. Upper jaw with 11(2), 12(4), 13(9), 14(6), 15(7), 10, rod-shaped, anterior to neural spines of 5th to 13th vertebrae (2). 16(2) or 17*(1) teeth with slightly convex border and 7–9 cusps. Pre- First dorsal-fin pterygiophore inserted immediately anterior to neural maxillary with 8(1), 9(1) or 10(1) and maxillary with 4(1) or 5(2) teeth. spine of 14th vertebra (2). Pelvic-fin rays i,9(4), i,10(23), i,11(4), ii,10* Adipose eyelid well developed, covering eye almost entirely, except (1) or 11(2). Dorsal-fin rays ii,9*(32) or ii,10(2); last ray adnate. Anal-fin for vertically elongate opening over pupil. First gill-arch with 18(2), rays ii,8(2), ii,9*(30) or ii,10(2). First anal-fin pterygiophore inserted 19(2), 20(2), 21(1), 22(3), 23(1), 25(1), 26(1), 27(3), 28(4), 29(1), immediately anterior to haemal arch of 31st vertebra (2). Caudal-fin 30(3) or 31*(1) gillrakers on ceratobranchial and 11(1), 13(1), 14(4), rays i,9 + i,8*(32). Total vertebrae 42(2) or 43(1). 15(1), 16(4), 17(1), 19(1), 20(2), 21*(5), 22(4) or 25(1) gillrakers on epibranchial. Branchiostegal rays four. Scales cycloid and equal in size above and below the lateral line. 3.1.5 | Colour in alcohol Lateral line series with 98(1), 101(2), 102(1), 103(1), 108(1), 110(5), Melanophores dispersed throughout body. Dorsal half of body yellow- 111(3), 112(1), 113(1), 114(3), 116(2), 118(3), 119*(3), 121(1) or 124 ish to dark brown, with V-shaped bars having the vertices directed (1) perforated scales. Scales above lateral line in transverse series posteriorly. Head darker than trunk, with no conspicuous colour 4 NOGUEIRA ET AL. FISH marks. Ventral half of the body yellowish throughout. Midlateral present a more restricted distribution: H. parnaguae is endemic to Par- blotch black with surrounding region less pigmented. Some specimens naíba Basin and H. orthonops occurs in the Paraguay and Paraná with inconspicuous longitudinal dark stripe from immediately poste- Basins (Langeani, 2003). Hemiodus bimaculatus is more similar to rior to midlateral blotch to caudal peduncle and lower caudal-fin lobe H. argenteus and H. microlepis, species that occur in the same basin stripe. Dark, horizontally elongated blotch onto the caudal peduncle (Amazon Basin). The recognition of Hemiodus bimaculatus as a distinct darker than longitudinal dark stripe. Dorsal, pectoral, pelvic and anal species may be indicative that the more widespread species (i.e., fins with scattered melanophores. Caudal-fin lobes well-pigmented H. argenteus, H. microlepis and H. orthonops) may, in fact, constitute with melanophores bordering rays. Lower caudal-fin lobe with con- species complexes and are in need of review. spicuous longitudinal dark stripe. 5 | COMPARATIVE MATERIAL 3.1.6 | Distribution Hemiodus bimaculatus is known only from tributaries of the Rio Juruena and the Rio Teles Pires in the upper Rio Tapajós basin, Mato In addition to the material listed in Langeani and Moreira (2013), the following specimens were also examined, all from Brazil. Grosso, Brazil (Figure 2). 5.1 | Hemiodus argenteus 3.1.7 | Etymology The specific epithet bimaculatus, an adjective, refers to the presence of two conspicuous dark blotches on the body: one at the midlateral flank and at the lateral surface of the caudal peduncle. CPUFMT 1467, 5, 73.7–83.0 mm LS, Mato Grosso, Lucas do Rio Verde, Rio Verde in Lucas do Rio Verde (Ponto 2, Montante, Vespertino, Arrasto). LBP 12868, 5, 121.1–142.2 mm LS, Pará, Itaituba, Rio Tapajós. LBP 15212, 4, 66.2–95.1 mm LS, Roraima, Bonfim, Rio Takutu. LBP 15569, 1, 89.4 mm LS, Roraima, Bonfim, Igarapé Chidaua. MPEG 1759, 1, 163.6 mm LS, Amazonas, Tefé, Rio Tefé, Lago Tefé. 4 | DISCUSSION MPEG 14879, 1, 170.7 mm LS, Pará, Faro, Lago do Arco. MPEG 26358, 3, 130.3–141.4 mm LS, Pará, São Félix do Xingu, Serra do Although lacking a comprehensive phylogenetic hypothesis, the spe- Jacaré (Anglo American Mining). MPEG 31257, 1, 168.0 mm LS, Ama- cies of Hemiodus have been organised into species groups based zonas, Parintins, Lake draining to the Paraná de Ramos. MPEG 31258, mainly on colouration pattern and the number of scales on the lateral 4, 70.6–87.0 mm LS, Pará, Óbidos, Lake in front of Óbidos. MPEG line series (Beltrão & Zuanon, 2012; Géry, 1977; Langeani, 1999; 34029, 5, 96.0–108.2 mm LS, Pará, Monte Dourado, Floresta Estadual Langeani & Moreira, 2013). Among such groups, H. bimaculatus is do Paru. MPEG 34030, 1, 94.8 mm LS, Pará, Monte Dourado, Floresta included in the H. microlepis group (sensu Langeani, 1999) by Estadual do Paru. MZUSP 32478, 8, 67.2–145.6 mm LS, Roraima, possessing more than 80 perforated lateral-line scales (98–124). Addi- Caracaraí, Rio Branco, Cachoeira do Bem-Querer. tionally, among the four valid species within the H. microlepis group, the new species is most similar to H. argenteus and H. microlepis given their closest scale counts (94–148 along lateral line, 19–36 above and 13–26 below lateral line in the two latter comparing with 22–28 5.2 | Hemiodus immaculatus LBP 16417, 1, 140.6 mm LS, Pará, Itaituba, arm of Rio Jamanxim. above and 14–19 below lateral line in H. bimaculatus) and similar colour pattern, marked by the conspicuous midlateral black blotch on the flanks and the lack of vertical bars or conspicuous longitudinal stripe 5.3 | Hemiodus microlepis in the trunk. However, the new taxon differs from the species of the LBP 12708, 1, 115.0 mm LS, Mato Grosso, Cocalinho, Rio Araguaia. H. microlepis group by the presence of the black blotch onto the cau- MPEG 339, 1, 131.0 mm LS, Amazonas, Tefé, Rio Tefé, Mucura. MPEG dal peduncle and by the number of gill-rakers on branchial arches (see 3003, 1, 147.9 mm LS, Maranhão, Maranhão, Rio Turiaçu, c. 1 km § 3.1.3). This unique and conspicuous combination of both blotches above and below the Guajá indigenous post. MPEG 3691, onto the flank and the caudal peduncle makes H. bimaculatus readily 2, 188.5–188.7 mm LS, Amazonas, Maraã, Rio Solimões, Costa Cap- distinguishable from congeners. ivara, Tefé. MPEG 5140, 1, 203.3 mm LS, Amazonas, Novo Airão, Rio Species of Hemiodus microlepis group have the broadest distribu- Negro, Anavilhanas. MPEG 5500, 2, 137.0–139.4 mm LS, Maranhão, tions in the genus and commonly occur throughout the Amazon low- Turiaçu, Rio Turiaçú, Alto Turiaçú Indigenous Reserve, Municipality of lands and large river channels. Among these species, H. argenteus is Turiaçú. MPEG 10087, 1, 116.0 mm LS, Pará, Juruti. MPEG 10696, the most widespread, occurring in both the Amazon and Orinoco 9, 90.9–119.7 mm LS, Pará, Tucuruí, Lago Tauá. MPEG 16505, Basins, some smaller coastal rivers of the Guiana Shield and north- 1, 131.8 mm LS, Pará, Marabá, Rio Itacaiúnas. MPEG 19724, eastern Brazil (e.g., Rupununi, Corantijn, Itapecuru and Mearim 1, 153.4 mm LS; MPEG 19736, 1, 158.8 mm LS; MPEG 19737, Basins). Hemiodus microlepis occurs in the Madeira (Amazon Basin), 2, 155.1–160.4 mm LS, Pará, Itaituba, Rio Tapajós. Miritituba village. Tocantins and Orinoco Basins. The two other species of the group MPEG 20889, 21, 97.1–137.3 mm LS, Maranhão, Alto Alegre do NOGUEIRA ET AL. 5 FISH F I G U R E 2 Geographic distribution of Hemiodus bimaculatus sp. nov. in the Rio Tapajós basin, showing the type locality ( ) and other localities ( ) 60 56 52 Ri o Ta pa jó s 4 Rio Juru ena 8 Ri oT ele sP ris es 12 16 Pindaré, Igarapé Jenipapo. MPEG 20890, 4, 119.9–134.9 mm LS, Óbidos. MPEG 34991, 1, 159.9 mm LS, Pará, Jacareacanga, Buburé Maranhão, village. Bom Jardim, Igarapé Igarapá. MPEG 21210, 3, 81.0–132.2 mm LS, Maranhão, Alto Alegre do Pindaré, Rio Zutíua. MPEG 21625, 3, 124.2–135.8 mm LS, Pará, Altamira, Senador José Porfírio, Rio Itatá. MPEG 24644, 2, 97.1–124.8 mm LS, Maranhão, Alto Alegre do Pindaré, Igarapé Timbira. MPEG 24720, 1, 102.0 mm 5.4 | Hemiodus orthonops LBP 1274, 1, 164.1 mm LS, Mato Grosso do Sul, Coxim, Rio Taquari. LS, Maranhão, Pindaré-Mirim, Olho d’água dos Carneiros. MPEG LBP 8571, 1, 93.3 mm LS, Mato Grosso, Barra do Bugres, Rio Paraguai. 26789, 4, 144.4–167.8 mm LS, Pará, Jacareacanga, Buburé village. LBP 19325, 4, 126.0–139.3 mm LS, Paraná, Porto Rico, Rio Paraná. MPEG 29661, 1, 99.2 mm LS, Pará, Vitória do Xingu, Ilha da MCP 10887, 2, 105.5–146.0 mm LS, Mato Grosso, Poconé, Rio Pixaim Fazenda. MPEG 29824, 1, 147.2 mm LS, Pará, Vitória do Xingu, Jer- at the Porto de Pixaim, 60 km from Poconé by the Transpantaneira icoá. MPEG 31301, 1, 150.1 mm LS, Pará, Óbidos, Lake in front of road (Paraguay River system). MCP 15776, 1, 94.5 mm LS, Mato 6 NOGUEIRA ET AL. FISH Grosso, Barra do Bugres, Stream at Porto Estrela, on the road Barra ZOOB ANK LSID INFORMATION do Bugres-Cáceres, 35 km S, of Barra do Bugres. MCP 15802, urn:lsid:zoobank.org:pub:992D44F6-9177-4603-8F43-767D25BDD0FE. 1, 168.2 mm LS, Mato Grosso, Barra do Bugres, Rio Bugres, em Barra urn:lsid:zoobank.org:act:8A63A280-0C30-4EFB-AB85-AFC664255A21. do Bugres (afluente do rio Paraguai). MCP 20380, 1, 91.1 mm LS, Mato Grosso do Sul, Passo do Lontra, Rio Miranda, na baía da Med alha. UFRGS 18333, 1, 265.3 mm LS, Mato Grosso do Sul, Agua Clara, Rio Verde. AUTHOR CONTRIBU TIONS A.F.N. and F.L. generated the data; A.F.N., F.L. and A.L.N–F interpreted the data and A.F.N. wrote the manuscript with input from all authors. 5.5 | Hemiodus parnaguae MCP 22077, 1, 90.2 mm LS, Maranhão, Timon, Igarapé do Pinto on the road Pará-Maranhão (BR 316), c. 58 km SE of Caxias. MCP OR CID Acácio F. Nogueira https://orcid.org/0000-0003-2636-194X 22079, 1, 82.0 mm LS, Piauí, Teresina, Rio Parnaíba in Nazária, on the road Teresina/Bom Jardim. MCP 22081, 2, 92.2–100.4 mm LS, Piauí, Teresina, Rio Poti in Boquinha. MCP 22528, 1, 99.3 mm LS, Piauí, Teresina, Rio Parnaíba in Caititus, by the ferry of the Cerâmica Caititus, on the road Teresina/Palmeirais. UFRGS 14445, 2, 45.3–53.7 mm LS, Piauí, Uruçuí, rio Parnaíba, Boa Esperança reservoir. 5.6 | Hemiodus semitaeniatus LBP 3825, 1, 56.2 mm LS, Mato Grosso do Sul, Aquidauana, Rio Negro. LBP 5106, 2, 62.3–71.8 mm LS, Mato Grosso, Cáceres, Lagoa Bairro Caiçara. LBP 15193, 1, 65.0 mm LS, Roraima, Bonfim, Rio Takutu. 5.7 | Hemiodus thayeria LBP 6858, 1, 144.2 mm LS, Amazonas, São Gabriel da Cachoeira, Rio Puranga. LBP 7025, 1, 50.3 mm LS, Amazonas, São Gabriel da Cachoeira, Igarapé Ya-Mirim. LBP 7071, 2, 46.2–52.7 mm LS, Amazonas, São Gabriel da Cachoeira, Igarapé Miuá. 5.8 | Hemiodus unimaculatus LBP 1578, 1, 127.3 mm LS, Mato Grosso, Barra do Garça, Rio das Garças. LBP 20510, 3, 157.0–173.5 mm LS, Amapá, Laranjal do Jari, Rio Jari. LBP 24573, 1, 120.7 mm LS, Rondônia, Primavera de Rondônia, Lake of the Rio Pimenta Bueno. 5.9 | Hemiodus vorderwinkleri RE FE RE NCE S Beltrão, H., & Zuanon, J. (2012). Hemiodus langeanii (Characiformes : Hemiodontidae), a new species from rio Amana, rio Maués-Açú drainage, Amazon basin , Brazil. Neotropical Ichthyology, 10, 255–262. Fricke, R., Eschmeyer, W. N. & R. van der Laan (2018). Catalog of Fishes: Genera, Species, References. In Eschemeyer's catalog of fishes. Retrieved from http://researcharchive.calacademy.org/research/ichthyology/catalog/ fishcatmain.asp Géry, J. (1977). Characoids of the World. Neptune City, NJ: T.F.H. Publications, Inc. Ltd. Langeani, F. (1996) Estudo filogenético e revisão taxonômica da família Hemiodontidae Boulenger, 1904 (sensu Roberts, 1974) (Ostariophysi, Characiformes). (PhD thesis). Universidade de São Paulo, São Paulo, Brazil). Langeani, F. (1998). Phylogenetic study of the Hemiodontidae (Ostariophysi: Characiformes). In L. R. Malabarba, R. E. Reis, R. P. Vari, Z. M. S. Lucena, C. A. S. Lucena. (Eds.), Phylogeny and Classification of Neotropical Fishes (pp. 145–160). Porto Alegre: Edipucrs. Langeani, F. (1999). New species of Hemiodus (Ostariophysi, Characiformes, Hemiodontidae) from the Rio Tocantins, Brazil, with comments on color patterns and tooth shapes within the species and genus. Copeia, 1999, 718–722. Langeani, F. (2003). Family Hemiodontidae. In R. E. Reis, S. O. Kullander, & C. J. Ferraris (Eds.), Check List of the Freshwater Fishes of South and Central America (pp. 96–100). Porto Alegre: Edipucrs. Langeani, F., & Moreira, C. R. (2013). Hemiodus iratapuru, a new species of Hemiodontidae from the Rio Jari, Amazon Basin, Brazil (Teleostei, Characiformes). Journal of Fish Biology, 82, 1259–1268. Roberts, T. (1974). Osteology and classification of the neotropical characoid fishes of thefamilies Hemiodontidae (including Anodontinae) and Parodontidae. Bulletin of the Museum of Comparative Zoology, 146, 411–472. Sabaj, M. H. (2016). Standard symbolic codes for institutional resource collections in herpetology and ichthyology. Washington, DC: American Society of Ichthyologists and Herpetologists. Retrieved from www.asih.org/sites/ default/files/documents/symbolic_codes_for_collections_v6.5_2016.pdf. Taylor, W. R., & Van Dyke, G. C. (1985). Revised procedures for staining and clearing small fishes and other vertebrates for bone and cartilage study. Cybium, 9, 107–109. LBP 19628, 1, 104.3 mm LS; LBP 20226, 1, 93.4 mm LS, Mato Grosso, Alta Floresta, Rio Apiacás. How to cite this article: Nogueira AF, Langeani F, NettoFerreira AL. Hemiodus bimaculatus, a new species of ACKNOWLEDGEMEN TS We thank C. A. S. Lucena (MCP) for loans, donation and curatorial work of specimens. Hemiodontidae from the Rio Tapajós drainage, Brazil (Ostariophysi: Characiformes). J Fish Biol. 2019;1–6. https:// doi.org/10.1111/jfb.13972