Leporinus obtusidens ( Valenciennes, 1837 )

Britski, Heraldo A., Birindelli, José Luís O. & Garavello, Julio Cesar, 2012, A New Species Of Leporinus Agassiz, 1829 From The Upper Rio Paraná Basin (Characiformes, Anostomidae) With Redescription Of L. Elongatus Valenciennes, 1850 And L. Obtusidens (Valenciennes, Papéis Avulsos de Zoologia 52 (37), pp. 441-475 : 441-475

Leporinus obtusidens ( Valenciennes, 1837)

Figures 7 , 8 , 9 and 10

Curimatus obtusidens Valenciennes, 1837: pl. 8, fig. 2 [type locality: Buenos Aires, Argentina] .

Leporinus obtusidens – Valenciennes, 1847:9 [new generic combination; description based on holotype of Curimatus obtusidens ] – Valenciennes, in Cuvier & Valenciennes, 1850:28 [holotype; specimen from “l’Amazone” (= “Tocantins à San-Juáo das Duas Barras); redescription] – Günther, 1864:51 [catalog] – Hensel, 1870:79 [Porto Alegre] – Günther, 1880:12 [reference] – Holmberg, 1889:364 [ Río de La Plata ; Misiones] – Eigenmann & Eigenmann, 1891:51 [catalog] – von Ihering, 1893:114; 1897:17 [ Rio dos Sinos , Porto Alegre, Rio Camaquam ] – Lahille, 1895:231 [Buenos Aires: Río de la Plata at Puerto La Plata and Isla Santiago] – Berg, 1897:282 [ Río de La Plata ; Río Paraná; Riachuelo; Canal del Dock Sud; Uruguay] – Boulenger, 1897:3 [Caiza; Misión de San Francisco,

Bolivia] – Eigenmann, 1907:452 [Buenos Aires] – Eigenmann, 1910:426 [reference] – Lahille: 1922:15 [reference] – Marelli, 1924:558 [reference] – Devincenzi, 1924:171 [ Río Santa Lucia, Uruguay] – Fowler, 1926:262 [La Plata] – Devincenzi & Barattini, 1926 -1940: pl. 11, fig. 3 [ Uruguay] – Pearson, 1937:109 [ Paraguay system] – Ringuelet, 1940:105 [Rosario] – Devincenzi & Teague, 1942:64, text-figure [ Río Uruguay Medio] – De Buen, 1950:88 [ Río de La Plata ] – Fowler, 1950:242, fig. 282 [copied from Steindachner, 1875] – Mastrarrigo, 1950:417 [Santa Fe, Río Paraná] – Bonetto, 1956:3,6 [Santa Fe] – Ringuelet & Arámburu, 1957:11 [“Paraná-Plata y aguas hasta la cuenca del Salado”] – Travassos, 1960:6 [catalogue] – Géry, 1960:279 [ Río de la Plata ] – Ringuelet & Arámburu, 1962:37 [reference] – Bonetto, 1963:18 [reference] – Marini & Lopes, 1963:81 [reference] – Ringuelet et al., 1967:219 [Buenos Aires, delta del Río Paraná; Corrientes, esteros at isla Apipé Grande; Misiones, San Ignacio; Salta, Río Juramento ; Río Bermejo at Luna Muerta; Santiago del Estero, Río Dulce , los Quirogas; Tucumán, Río Salí, Los Gomez ; Río de Abajo, Burruyacú ] – Occhi & Oliveros, 1974:77 [Santa Fe, Río Paraná, feeding habits] – Géry, 1977:163 [diagnosis in key] – Bonetto et al., 1978: table 1 [ Río Riachuelo, Prov. Corrientes, Argentina] – Miquelarenas, 1984:614 [ Río Uruguay, frente a la desembocadura del Gualeguaychú; Rio Paraná; Santa Fe; Riacho El Carrizal, Bella Vista, Corrientes; caudal-fin skeleton] – Miquelarenas, 1986:4 [teeth morphology] – Géry et al., 1987:392, fig. 20 [data on holotype; localities in Paraguay, Argentina and Brazil] – Malabarba, 1989:126 [Laguna dos Patos; comments on species distribution] – Braga, 1992:33 [Argentinean localities] – Gómez & Chebez, 1996:54 [Missiones] – Sverlij et al., 1998:29 [ Río Uruguay; data on biology] – Britski et al., 1999:78 [Pantanal Mato-Grossense] – Butí & Cancino, 1999:71 [ Río Hondo , Tucuman, Santiago del Estero] – Chernoff & Willink, 2000a:87 [Pantanal do Mato Grosso] – Chernoff & Willink, 2000b:207 [Pantanal do Mato Grosso] – Menezes et al. 2000:291 [ Rio Negro, Pantanal do Mato Grosso] – Garavello & Britski, 2003:75 [catalog] – López et al., 2003:13 [reference] – Menni, 2004:72 [reference] – Britski & Garavello 2005:82 [reference] – Casciotta, Almirón & Bechara, 2005:117 [Esteros del Iberá; description, habitat, biology] – Liotta, 2005:75 [localities in Argentina] – Britski & Garavello, 2007:26 [catalog] – Britski et al., 2007:101 [Pantanal Mato-Grossense] – Almirón et al., 2008:58, text-figure [Parque Nacional Pre-Delta; arroyos Los Dorados y La Ensenada; description, habitat, biology] – Birindelli & Britski, 2009:8 [reference].

Leporinus elongatus – Valenciennes, in Cuvier & Valenciennes, 1850:37 [in part: paralectotype of Leporinus elongatus from Río de La Plata , Buenos Aires; not lectotype from Rio São Francisco ] – Günther, 1864:309 [copied] – Lütken, 1875:195 [ Rio das Velhas ; Rio São Francisco ; Rio Cipó ] – Steindachner, 1875:216, pl. 2, fig. 1 [ Río de la Plata in Buenos Ayres, Rio São Francisco and Rio das Velhas ; Rio Grande do Sul] – Perugia, 1891:641 [Banco del Cuigio, Río de La Plata ] – Lahille, 1895:269 [ Isla Santiago] – Campos, 1945a:150, text-figure [ Rio São Francisco , Minas Gerais and Bahia; Campo Grande, Alto da Serra, São Paulo ; Rio Mogi-Guaçu, Pirassununga , São Paulo ] – Campos, 1945b:446 [ Rio Mogi-Guaçu ] – Fowler, 1950:231 [catalog] – Gomes & Monteiro, 1955:143 [ Rio Mogi-Guaçu, Emas ] – Schubart, 1962:28 [ Rio Mogi-Guaçu ] – Godoy, 1975:339 [ Rio Mogi-Guaçu ; fishery, biological data] – Géry, 1977:171 [diagnosis in key] – Britski et al., 1984:57, fig. 65 [Represa de Três Marias, Rio São Francisco ] – Agostinho et al., 1997 b:184 [ Rio Paraná basin above Sete Quedas] – Hahn et al., 1997:212 [trophic ecology] – Agostinho et al., 1997 a:235 [trophic structure] – Vazzoler et al., 1997:252 [reprodution areas] – Pavanelli et al., 1997:310 [parasites] – Johannes, 1999:16 [reference] – Shibatta & Dias, 2006:53, text-figure [description, biology, fishery].

Leporinus bimaculatus – Castelnau, 1855:58 [in part: paralectotype NMHN A8620 from “ Tocantins à San-Juáo das Duas Barras ”, not lectotype herein designated from “ Rio Vermelho de Goyas ”] .

Leporinus pachyurus – Günther, 1864:308 [ Rio Cipó ].

? Leporinus leschenaultii – Perugia, 1891:641 [Vila Maria, Rio Paraguai, Mato Grosso].

Leporinus silvestrii Boulenger, 1902:284 [type locality Rio Coxipó , Mato Grosso] – Eigenmann, 1910:426 [reference] – Fowler, 1950:246 [catalog] – Tortonese, 1961:184 [catalog: 3 syntypes] – Johannes, 1999:16 [reference] – Garavello & Britski, 2003:78 [catalog] – Britski & Garavello, 2007:26 [catalog]. Syn. nov.

Leporinus piau – Fowler, 1941:176 [in part, paratypes from Rio São Francisco , not holotype from Rio Salgado or paratype from Rio Jaguaribe ].

Leporinus aguapeiensis Campos, 1945a:155 , photo [type locality Rio Aguapeí , São Paulo ] – Fowler, 1950:228 [catalog] – Britski, 1969:204 [data on presumed hototype] – Johannes, 1999:16 [reference] – Garavello & Britski, 2003:74 [catalog] – Britski & Garavello, 2007:24 [catalog]. Syn. nov.

Leporinus copelandi – Campos, 1945a:146, text-figure [in part, specimen from Rio Mogi-Guaçu, Pirassununga , São Paulo ].

Leporinus conirostris – Campos, 1945a:147 [in part, specimen from Rio Piracicaba , São Paulo ].

Leporinus reinhardti – Campos, 1945a:148 [specimens from Rio Miranda, Salobra , Mato Grosso ( MZUSP 34570)].

Leporinus affinis – Brenner, Quaglia & Cattaneo, 1954:192 [ Río de la Plata ].

Leporinus cf. obtusidens – Nakatani et al., 2001:150, text-figure [eggs and larvae].

Material examined: Lower Rio Paraná basin ( Argentina): MNHN 1693 (holotype of Leporinus obtusidens , 209.0 mm SL), Río de La Plata , Buenos Aires, A. d’Orbigny. MNHN 9800 (1 paralectotype of Leporinus elongatus , 256.0 mm SL), Río de La Plata , Buenos Aires, A. D’Orbigny. ILPLA 751 (1, 89.7 mm SL), near Boca Mocoreta, Corrientes, 09 Mar 1993, A. Espinach Ros et al. ILPLA 766 (2, unmeasured), near Boca Mocoreta, Corrientes, 09 Mar 1993, A. Espinach Ros et al. ILPLA 783 (1, 98 mm SL), Gualeguaycito, Entre Ríos, 11 Mar 1993, A. Espinach Ros et al. ILPLA 788 (1, 93.8 mm SL), Brazo Mocoreta, near mouth, Corrientes, 09 Mar 1993, A. Espinach Ros et al. ILPLA 797 (12, 72.9-93.2 mm SL), Itapebi, 12 Mar 1993, A. Espinach Ros et al. ILPLA 800 (8, unmeasured), Brazo Mocoreta, Entre Ríos, 09 Mar 1993, A. Espinach Ros et al. ILPLA 801 (1, 115.6 mm SL), Brazo Mandisovi, Entre Ríos, 10 Mar 1993, A. Espinach Ros et al. ILPLA 798 (2, 118.6- 147.4 mm SL), Gualeguaycito, Entre Ríos, 11 Mar 1993, A. Espinach Ros et al. IML 379 (2, 177- 225 mm SL), Dique los Quirogas, Santiago del Estero, 02 Sep 1951, S.A. Pierotti. IML 582 (1, 222 mm SL), Río Marapa, Chicligasta , Tucumán, 27-28 Mar 1953. MLP 477 (2, 99.7-99.8 mm SL), Ensenada, Buenos Aires, 04 Aug 1932. MLP 571 (2, 135- 164.3 mm SL), Río de La Plata , Buenos Aires, 16 Jul 1938. MLP 1384 (1, 128.2 mm SL), Río de La Plata , Buenos Aires, 30 May 1933. MLP 1674 (1, unmeasured), Posadas, Misiones, 05 Jun 1935. MLP 3083 (1, 143.6 mm SL), Arroyo Punta Índio, Buenos Aires, 04 Jan 1942, E. Mac Donagh. MLP 3341 (3, 67.1-74.1 mm SL), Debil, Entre Ríos, 03 Jun 1943, Comisión Umana-Risso. MLP 5880 (17, unmeasured), Punta Larc, 26 Oct 1950, Comisión Museo. MLP 6700 (1, unmeasured), Lago Parque Belgrano, Santa Fe, 08 Jul 1960, M. Galván & E. Martin. MLP 6769 (1, 73.8 mm SL), Lago Setubal, Santa Fe, 11 Jul 1960, M. Galván. MLP 6783 (1, 88.6 mm SL), Laguna Setubal, Santa Fe, 11 Jul 1960, M. Galván & E. Martin. MLP 6807 (1, 133.2 mm SL), Rosario, Santa Fe, 12 Jul 1960, Dr. Vidal. MLP 6982 (1, 68.2 mm SL), between Tocuareubi and San Antonio, 06 Jul 1961, M. Galván & E. Martin. MLP 7018 (1, 63.3 mm SL), Las Toscas, Santa Fe, 07 Jul 1961, M. Galván & E. Martin. MLP 7147 (1, 89.4 mm SL), Laguna Guadalupe, Santa Fe, 09 Jul 1961, M. Galván & E. Martin. MLP 7231 (3, 47.6-71.1 mm SL), Laguna Guadalupe, Santa Fe, 11 Sep 1961. MLP 7258 (1, 153.9 mm SL), Lago Parque Sur, Santa Fe, 11 Sep 1961, A. Bonetto. MLP 7283 (10, 79.1-149 mm SL), Madrejón near Río Colastiné , Santa Fe, 02 Dec 1961, R. Ringuelet & R. Arámburu. MLP 7295 (2, 76-105.9 mm SL), Río Colastiné , Santa Fe, 12 Oct 1961, R. Ringuelet & R. Arámburu. MLP 7948 (2, 113.4- 119.9 mm SL) Toba, Resistencia, Chaco, 02 Mar 1968, M. Galván. MLP 8014 (1, 145.9 mm SL), Resistencia, Chaco, 04 Apr 1968. MLP 8026 (1, 94.1 mm SL), Resistencia, Lago del Japones, Chaco, 05 May 1968. MLP 8078 (1, 124 mm SL), Estero Colonia Benitez, Resistencia, Chaco, 06 Jul 1968, M. Galván. MLP 8079 (1, 136 mm SL), Estero Colonia Benitez, Resistencia, Chaco, 06 Jul 1968, M. Galván. MLP 8121 (1, 147.4 mm SL), Lake near Puente Río Salado, Resistencia , Chaco, 07 Jun 1968, M. Galván. MLP 9264 (2, 76.5 mm SL), Paraná Pavon, Entre Ríos, 03 Jun 1943, Comision Umana-Risso. MLP 9333 (1, 121.6 mm SL), Entre Ríos, 02 Feb 1950, Daneri. MACN 4637 (1, 179 mm SL), Estero Santa Lucía, Mananciales, Corrientes, Dec 1959, I. Apostol. MACN 4814 (1, 89 mm SL), Río Paraná, Ramallo, Buenos Aires, Aug 1961, Sr. Tonina. MACN 5060 (1, 160 mm SL), Río Paraná Guazú, Islas del Ibicuy, 06 Oct 1963, E. Grancelli. MACN 8007 (2, 253.3- 253.9 mm SL), confluence of Río Paraná and Río Paraguay, Sr. O. Greja. MACN 2948 (1, 238.8 mm SL), Riacho Brazo Chico (Ibicuicito Delta), Mar 1942, Sr. S. Siciliano. MACN 4585 (2, 144- 182.7 mm SL), Laguna, south of Coronda, Santa Fe, Sep 1960. MACN 3485 (1, 153.8 mm SL), Río de La Plata, Sr. S. Siciliano. MACN 3619 (2, 113.3- 113.5 mm SL), Río de La Plata , no other data. MACN 3622 (3, 105- 128.5 mm SL), Riachuelo, 11 Oct 1899, Sr. Chimpf. MACN 5060 (1, 155.8 mm SL), Río Paraná-Guazú, Islas del Ibicuy, 06 Oct 1963, E. Grancelli. MACN 6761 (3, 107.2- 141.5 mm SL), Río Paraná and/or Río de La Plata. MCZ 20375 (1, 250 mm SL), Buenos Aires, H. Wheatland (Essex Institute). MZUSP 41876 (1, 500 mm SL), Río Paraná, Corrientes, Argentina. MZUSP 48465 (2, 117- 118.2 mm SL), Río Salado , near INALI, 20 Mar 1972, INALI. MZUSP 48739 (3, 62.4-86.4 mm SL), Laguna 5, at Isla Los Sapos, Rio Paraná basin, Argentina, 22 Apr 1972, INALI. MZUSP 107842 (4, 73.3-97.3 mm SL), Río Paraná de las Palmas, near Zarate, Buenos Aires, Argentina, 1960. NMW 69591 (1, 133.9 mm SL), Buenos Ayeres. Rio Uruguai basin ( Brazil, unles noted): MACN 6131 (7, 181- 192 mm SL), Río Uruguay, San Marcos, Uruguay, 27 Jul 1947, A. Nani. MACN uncatalogued (4, 150 mm SL), Río Uruguay, near Sto. Tomé, Uruguay, 22 Jul 1947. MCP 10178 (1, 151.1 mm SL), Arroio Quaraí-Chico, at Barra do Quarai, Uruguaiana, Rio Grande do Sul, 16 Nov 1994, L. R. Malabarba & R.E. Reis. MCP 12758 (1, 350 mm SL), Rio Uruguai, at Porto de Santo Izidro, São Nicolau , Rio Grande do Sul, 03 Jan 1989, R.E. Reis et al. MCP 12817 (1, 330 mm SL), Rio Uruguai, at Porto de Santo Izidro, São Nicolau , Rio Grande do Sul, 03 Jan 1989, R.E. Reis et al. MCP 13794 (1, 335 mm SL), Rio Uruguai, at Porto de Santo Izidro, São Nicolau , Rio Grande do Sul, 03 Jan 1989, R.E. Reis et al. MZUSP 1963 (1, 103.8 mm SL), Río Uruguai, Itaqui, Rio Grande do Sul, 1914, E. Garbe. MZUSP 3513 (1, 155.4 mm SL), Rio Uruguai, Itaqui, Rio Grande do Sul, 1914, E. Garbe. MZUSP 63659 (1, 160 mm SL), Rio Uruguai, Itaqui, Rio Grande do Sul, 1914, E. Garbe. Upper Rio Paraná basin ( Brazil): MZUSP 1913 (1, 161 mm SL), Campo Grande, Alto da Serra, São Paulo, Jan 1909 , Luederwaldt [identified as L. elongatus by Campos, 1945a:151]. MZUSP 3442 (1, 170.9 mm SL), Rio Mogi Guaçu , at Cachoeira de Emas, São Paulo, 1943 , O. Schubart [identified as L. elongatus by Campos, 1945a:151]. MZUSP 3449 (1, 298 mm SL), Rio Mogi Guaçu , at Cachoeira de Ema, Pirassununga, São Paulo, 1943 , O. Schubart [identified as L. copelandi by Campos, 1945a:146]. MZUSP 3643 (1, 335 mm SL), Rio Mogi Guaçu , at Cachoeira de Emas, Pirassununga, São Paulo, 1945 , O. Schubart. MZUSP 21095 (6, 103- 335 mm SL), Rio Paraná, below Sete Quedas, Paraná, 1977-1980, CETESB. MZUSP 21097 (4, 298- 380 mm), Rio Paraná, below Sete Quedas, Guaira, Paraná, 1977-1980, CETESB. MZUSP 21624 (10, 95.5-380 mm SL), Rio Paraná, above Sete Quedas, Guaira, Paraná, 1977-1980, CETESB. MZUSP 25334 (7, 72.1-89 mm SL), Rio Mogi Guaçu , at Cachoeira de Emas, Pirassununga, São Paulo, 1960 -1970, Excursão do Departamento de Zoologia da Secretaria de Agricultura do Estado de São Paulo. MZUSP 38913 (20, 131.6- 400 mm SL), Rio Paranaíba , at UHE Bocaina, Minas Gerais, Nov 1987 to Jun 1988, Leme Engenharia S/A. MZUSP 42985 (1, 223.8 mm SL), mouth of Riacho Caracu (22°45’S, 53°15’W), tributary of Rio Paraná, Porto Rico, Paraná, Feb 1988, NUPELIA. MZUSP 42995 (1, 109.5 mm SL), Rio Paraná (22°45’S, 53°17’W), Porto Rico, Paraná, 25 Jul 1987, NUPELIA. MZUSP 43006 (1, 144 mm SL), Rio Samambaia , tributary of Rio Paraná (22°41’S, 53°16’W), Taquaruçu, Mato Grosso do Sul, 24 Feb 1988, NUPELIA. MZUSP 43012 (1, 149.6 mm SL), Lagoa Pousada das Garças, at Rio Samambaia bay, Taquaruçu, Mato Grosso do Sul, 24 Feb 1988, NUPELIA. MZUSP 43033 (1, 105.6 mm SL), Rio Paraná, at Reservatório de Itaipu, near São João (24°08’S, 54°20’W), Guaíra, Paraná, 21 Oct 1987, NUPELIA. MZUSP 43034 (1, 255 mm SL), Rio Paraná, at Reservatório de Itaipu (24°08’S, 54°20’W), Guaíra, Paraná, 04 Apr 1987, NUPELIA. MZUSP 43036 (1, 110.6 mm SL), Rio Paraná, at Reservatório de Itaipu, Guairá, Paraná, 20 Oct 1987, NUPELIA. MZUSP 43037 (1, 246 mm SL), Rio Paraná, at Reservatório de Itaipu (24°03’S, 54°15’W), 15 Feb 1988, NUPELIA. MZUSP 43078 (1, 90 mm SL), Rio Carambaí , tributary of Rio Paraná, at Reservatório de Itaipu (24°06’S, 54°16’W), Guaíra, Paraná, 26 Mar 1989, NUPELIA. MZUSP 43083 (2, 230.3- 228.3 mm SL), Lagoa Saraiva, Rio Paraná basin, at Ilha Grande (23°59’S, 54°02’W), Altonia, Paraná, 26 Apr 1988, NUPELIA. MZUSP 43084 (1, 207 mm SL), mouth of Rio Branco , tributary of Rio Paraná, Reservatório de Itaipu at Pato Bragado (29°25’S, 54°12’W), Marechal Cândido Rondon, Paraná, 13 Apr 1989, NUPELIA. MZUSP 43085 (1, 225 mm SL), Rio Ivinheima , tributary of Rio Paraná (22°48’S, 53°34’W), Taquaruçu, Mato Grosso do Sul, 28 Mar 1988, NUPELIA. MZUSP 43086 (1, 318 mm SL), Rio Paraná, at Reservatório de Itaipu, Santa Helena, Paraná, 02 Oct 1989, NUPELIA. MZUSP 43090 (1, 470- 510 mm SL), Rio Paraná, below Reservatório de Itaipu, Foz do Iguaçu, Paraná, 29 Jul 1988, NUPELIA. MZUSP 43091 (1, 208 mm SL), Rio Piqueri , tributary of Rio Paraná, at Apertado (24°11’S, 53°19’W), Formoso do Oeste, Paraná, 25 Nov 1989, NUPELIA. MZUSP 48426 (6, 184.6- 252 mm SL), Rio Grande, Marimbondo , São Paulo , 20 Nov 1975, CETESB. MZUSP 48428 (7, 145.5- 190 mm SL), Rio Sucuriú, Três Lagoas , Mato Grosso do Sul, 31 Jan 1975, R. Storti & A. Storti. MZUSP 48429 (1, 155 mm SL), Rio Paraná, Porto Cabral, São Paulo , 03 Apr 1944, L. Travassos Filho & E. Dente. MZUSP 48430 (1, 181.3 mm SL), Rio Grande , at Represa de Furnas, Boa Esperança, Minas Gerais, 26 Nov 1975, CETESB. MZUSP 48433 (2, 265- 300 mm SL), Rio Pardo , at Usina de Limoeiro, São José do Rio Pardo , São Paulo , 13 Apr 1965, H.A. Britski. MZUSP 48434 (1, 158.3 mm SL), Rio Paranapanema , São Paulo , May 1945, E. Dente. MZUSP 48435 (4, 205- 252 mm SL), Rio Grande , at Represa de Volta Grande, Miguelópolis, São Paulo , 06-07 Nov 1975, CETESB. MZUSP 48657 (1, 158 mm SL), Rio Verde , tributary of Rio Paraná, Mato Grosso do Sul, 24 Aug 1941, J. Canella. MZUSP 48658 (1, 189- 196.2 mm SL), Rio Grande , at Represa de Camargos, Minas Gerais, 23 Oct 1975, CETESB. MZUSP 48700 (37, 50.4-91 mm SL), Rio Paraná (cofferdam), Ilha Solteira, Mato Grosso do Sul, 25-28 May 1972, Excursão do Departamento de Zoologia. MZUSP 48718 (1, 184 mm SL), Rio Grande , at Represa de Itutinga, Minas Gerais, 23 Oct 1975, CETESB. MZUSP 48724 (2, 208.6- 259.2 mm SL), Rio Mogi Guaçu , at Cachoeira de Emas, Pirassununga, São Paulo , 29 Jul 1962, Excursão do Departamento de Zoologia da Secretaria de Agricultura do Estado de São Paulo. MZUSP 48733 (6, 71.6-136.4 mm SL), Rio Paraná, at Jupiá, Mato Grosso do Sul, 15-23 Sep 1962, Excursão do Departamento de Zoologia da Secretaria de Agricultura do Estado de São Paulo. MZUSP 48783 (1, 245 mm SL), Rio Mogi Guaçu , at Cachoeira de Emas, Pirassununga, São Paulo, Jul 1973 , U. Burheim. MZUSP 48784 (2, 79.7-114 mm SL), Marginal lagoon of the Córrego do Moinho, tributary of Rio Paraná, Alfredo Castilho, São Paulo , 11-23 Sep 1964, Excursão do Departamento de Zoologia da Secretaria de Agricultura do Estado de São Paulo. MZUSP 48810 (2, 144.3- 147 mm SL), Rio Tietê , at Reservatório de Jurumirim, São Paulo , 28 aug 1963, Departamento de Produção Animal. MZUSP 48819 (3, 245- 295 mm SL), Rio Pardo , at UHE Limoeiro, São Paulo , 29 Feb 1964, C.M. Machado. MZUSP 48820 (3, 285.6- 313.8 mm SL), Rio Paraná, at Jupiá, 11-23 Sep 1964, Excursão do Departamento de Zoologia da Secretaria de Agricultura do Estado de São Paulo. MZUSP 53797 (1, 249.1 mm SL), Rio Atibaia , at REPLAN (22°44’82”S, 47°07’58”W), Jaguariúna, São Paulo , 13 Dec 1998, O. Oyakawa et al. MZUSP 63686 (1, 171.4 mm SL), Campo Grande, Alto da Serra, São Paulo, Jan 1909 , Luederwaldt [= MZUSP 1913]. MZUSP 70383 (1, 284.3 mm SL), Rio Mogi Guaçu , at Cachoeira de Emas, Pirassununga, São Paulo , May 1999, S.C. Carneiro. MZUSP 78508 (1, 119.7 mm SL), Rio Araguari , tributary of Rio Paranaíba , at Reservatório de Nova Ponte, Minas Gerais, Oct 2001, V. Vono. MZUSP 82412 (1, 196.5 mm SL), Rio Atibaia , at Fazenda Santa Paula, Campinas, São Paulo , 19 Mar 2003, A.M. Zanata & M.P. Geraldes. MZUSP 84758 (1, 350 mm SL), Rio Sorocaba, Cerquilho , São Paulo , 14 Jun 2004, J.L.O. Birindelli & C. R. Moreira. MZUSP 92995 (4, 210- 375 mm SL), Rio Piracicaba , near Ripasa, Americana, São Paulo , 30 Aug 2006, H.A. Britski & O. T. Oyakawa. MZUSP 105067 (1 sk, 390.0 mm SL), purchased in fish market in São Paulo, 2010 , J.L.O. Birindelli et al. MZUSP 107168 (10, 172.9- 259 mm SL), Rio Grande , São Paulo, Sep 1980 , CESP-Promissão. MZUSP 107170 (6, 104.2- 340 mm SL), Rio Araguari , Nova Ponte, Minas Gerais, 15 Oct 1986, E. Zaniboni Filho. MZUSP 107171 (10, 136.3- 380 mm SL), Rio Paraná (cofferdam) (20°15’S, 51°07’W), Ilha Solteira, São Paulo, Sep 1965 , Excursão do Departamento de Zoologia da Secretaria de Agricultura do Estado de São Paulo. MZUSP 107210 (1, 305 mm SL), Rio Grande , at Cachoeira da Onça, 06-07 Jan 1962, São Paulo, P.E. Vanzolini et al. MZUSP 107841 (3, 113.5- 129.3 mm SL), Rio Araguari , at Salto de Nova Ponte, Nova Ponte, Minas Gerais, 20 Mar 1987, G.B. Santos. MZUSP 107844 (1, 147.7 mm SL), Rio Tietê , below UHE Bariri (22°08’50”S, 48°45’06”W), São Paulo , 03-07 Nov 2003, A. Akama. MZUSP 107846 (8, 104.1- 217 mm SL), Rio Pardo, Caconde , São Paulo , 08-12 Jan 1979, CESP. MZUSP 107852 (1, 167.4 mm SL), Rio Tietê , at Reservatório de Barra Bonita, Barra Bonita, São Paulo, Jan 2001 , W.S. Smith. MZUSP 107845 (2, 96.3-157.1 mm SL), Rio Piracicaba (22°38’27,1”S, 48°09’51,0”W), Piracicaba, São Paulo, Jan 2001 , W.S. Smith. MZUSP 107853 (7, 105.3- 238 mm SL), Rio Paranapanema , at Promissão, São Paulo, Aug 1980 , CESP. MZUSP 107273 (4, 232- 255 mm SL), Rio Paraná, Promissão, São Paulo , 29 Oct 1992, CESP. MZUSP 107272 [ex. MZUSP 48808] (1, 83.4 mm SL), Rio Mogi Guaçu , at Cachoeira de Emas, Pirassununga, São Paulo , 20 Aug 1963, P.E. Vanzolini & H.A. Britski. Rio Paraguay basin ( Brazil): BMNH 1902.2.10.32 (holotype of Leporinus silvestrii , 150.0 mm SL), Rio Coxipó, Matto Grosso, Silvestri, 1900 . BMNH 1935.6.4.317-318 (2, 113.0- 162.1 mm SL), Río Paraguay, Assunción, Paraguay, Schauten. CAS 70581 (1, 165.7 mm SL), Río Paraguay, Assución, Paraguay, J.D. Anisits. FMNH 71238 (1, 109.6 mm SL), Piraputanga, Mato Grosso do Sul, 13 Jul 1926, J.D. Haseman. MZUSP 38165 (1, 206.3 mm SL), Rio Coxipó da Ponte , at São Gonçalo, Cuiabá , Mato Grosso, 16-22 Apr 1981, Equipe Ictiologia da UFSCar. MZUSP 41577 (2, 166.4- 191.3 mm SL), Córrego do Mato, at Fazenda Córrego do Mato, Rio Taquari basin, Alto Araguaia, Mato Grosso, 09 Mar 1989, L.P.S. Portugal & F. Langeani. MZUSP 42751 (1, 84.8 mm SL), Rio Cuiabá, Barão de Melgaço , 04-10 May 1977. MZUSP 48431 (1, 260 mm SL), Rio Miranda, Guia Lopes da Laguna , Mato Grosso do Sul, 24-27 Dec 1975, A. Ziolkowski & E. Bobadilha. MZUSP 48432 (1, 250.8 mm SL), Rio Taquari , at Cachoeira das Palmeiras, MS, 08 Dec 1976, CEPIPAM. MZUSP 48462 (1, 182.9 mm SL), Rio Taquari , 150 km from Coxim, Mato Grosso do Sul, 09-22 Aug 1967, A. Cozza & J.C. Garavello. MZUSP 48464 (1, 67.1 mm SL), Rio Cuiabá, Sangradouro Grande, Barão de Melgaço , Mato Grosso, 16 Mar 1977, CEPIPAM. MZUSP 48468 (1, 212.6 mm SL), Rio Paraguai, at Descalvado, Cáceres, Mato Grosso, 22-24 Jan 1977, CEPIPAM. MZUSP 48781 (4, 240- 425 mm SL), Rio Miranda, Guia Lopes da Laguna , Mato Grosso do Sul, Feb 1975, A. Ziolkowski & E. Bobadilha. MZUSP 48817 (8, 193.7- 274 mm SL), Rio Taquari, Coxim , Mato Grosso do Sul, 15 Jul 1975, A. Storti & W. Uieda. MZUSP 60015 (1, 135.8 mm SL), Brejo da Santa Sofia (19°35’89”S, 56°20’47”W), Aquidauana, Mato Grosso do Sul, 03 Sep 1998, A. Machado et al. MZUSP 62415 (1, 85.3 mm SL), Rio Cuiabá, Santo Antonio do Leverger, Mato Grosso, 1965, Gary Olson. MZUSP 62416 (1, 360 mm SL), Rio Manso , at UHE do Manso, Mato Grosso, 1999, K. de Silimon. MZUSP 90238 (1, 67.8 mm SL), Rio Sepotuba , (15°47’33”S, 57°39’20”W), Cáceres, Mato Grosso, 02 Mar 2002, H.A. Britski et al. Rio Guaíba basin ( Brazil): MCP 9697 (5, 73.9-113.1 mm SL), Rio Guaíba , at Morro da Ponta Grossa, Porto Alegre, Rio Grande do Sul, Dec 1983, Bertoletti et al. MCP 10013 (1, 134.5 mm SL), Creek near road BR-290, Eldorado do Sul, Rio Grande do Sul, 18 Sep 1983, C.A. Lucena & L. R. Malabarba. MCP 10515 (1, 278 mm SL), Rio Guaíba , at Ponta Grossa, Porto Alegre, Rio Grande do Sul, 27 Sep 1985, Bertoletti et al. MCP 10519 (4, 102.6- 286.2 mm SL), Rio Guaíba at Ponta do Jacaré (Saco dos Macacos), Barra do Ribeiro, Rio Grande do Sul, 17 Dec 1984. MCP 10553 (1, 215 mm SL), Rio Guaíba , at Ponta do Jacaré, Barra do Ribeiro, Rio Grande do Sul, 27 Sep 1985, E. Lerner et al. MCP 14063 (1, 405 mm SL), Lago Guaíba, at beach of Itapuã (30°05’S, 51°02’W), Viamão, Rio Grande do Sul, 25 Aug 1987, L.E. Pereira. MCP 14762 (1, 258 mm SL), Rio Guaíba , at Ponta do Jacaré, Barra do Ribeiro, Rio Grande do Sul, 23 Jan 1991, J.F. Pezzi da Silva et al. MCZ 850 (1, 305 mm SL), Lagoa dos Patos, Rio Grande , Porto Alegre, Rio Grande do Sul, J. McChintz. MCZ 20448 (2, 250- 275 mm SL), Rio Grande do Sul, Emperor collection. MZUSP 48425 (2, 105.1- 116.8 mm SL), Delta of Rio Jacuí , Porto Alegre, Rio Grande do Sul, 03 Nov 1978, P.A. Buckup. Rio São Francinsco basin ( Brazil): ANSP 69503-7 (4 paratypes of Leporinus piau , 32.6-45.3 mm SL), Rio São Francisco, Jatobá , Pernambuco, 1937, R. von Ihering. MCZ 20451 (1, 233 mm SL), Rio das Velhas at Jequitibá, Minas Gerais, Jul 1865, J.A. Allen & O. St. John. MCZ 20452 (1, 208.6 mm SL), Rio das Velhas , Minas Gerais, Jul 1865, J.A. Allen & O. St. John. MCZ 20453 (4, 207.2- 243 mm SL), Rio das Velhas , Minas Gerais, Jul 1865, J.A. Allen & O. St. John. MCZ 20456 (1, 119.9 mm SL), Rio das Velhas , Minas Gerais, Jul 1865, J.A. Allen & O. St. John. MCZ 20459 (3, 182.2- 188.5 mm SL), Rio São Francisco , between Guaicui and Januaria, Minas Gerais, 28 Aug 1865, J.A. Allen & O. St. John. MCZ 20488 (1, 121.7 mm SL), Rio São Francisco bellow falls, 1867, Hartt. MCZ 20489 (2, 99.5-105 mm SL), Rio São Francisco bellow falls, 1867, Hartt. MCZ 95468 [ex. MCZ 20458] (1, 225 mm SL), Rio São Francisco at Januaria, 09 Sep 1865, J.A. Allen & O. St. John. MZUSP 1371 (1, 130.9 mm SL), Rio São Francisco, Pirapora , Minas Gerais, 1913, E. Garbe. MZUSP 1445 (2, 140.5- 147 mm SL), Rio São Francisco (17°21’S, 44°57’W), Pirapora, Minas Gerais, 1912, E. Garbe. MZUSP 1964 (3, 131.4- 135.7 mm SL), Rio São Francisco, Pirapora , Minas Gerais, 1912, E. Garbe. MZUSP 14537 (8, 124.4- 233 mm SL), Rio São Francisco, Própria , Sergipe, 06 Nov 1975, A. V. Alcântara. MZUSP 28773 (5, 134.3- 148 mm SL), Rio Desidério , São Desidério , Bahia, 02-06 May 1985, M.C. Cestarolli & J. Camargo. MZUSP 39733 (1, 224.3 mm SL), Rio São Francisco , at UHE Formoso, Minas Gerais, 1987-1888, I. Sato. MZUSP 47314 (4, 87.9-106.1 mm SL), Tributary of Rio Jequitaí , on road BR 135, between Buenópolis and Engenheiro Dolabela, 26 Jul 94, Expedição MZUSP / USNM /UFSCar. MZUSP 48037 (6, 162.7- 390 mm SL), Rio São Francisco, Três Marias , Minas Gerais, 1978, CODEVASF. MZUSP 54757 (1, 167.7 mm SL), Rio Verde Grande (16°29’01”S, 43°42’49”W), Montes Claros, Minas Gerais, 20 Jul 1993, R.E. Reis et al. MZUSP 70737 (1, 164.3 mm SL), Fish market, Barra, Bahia. MZUSP 51521 (2, 161.4- 315 mm SL), Rio Paraopeba , tributary of Rio São Fransico , at Arrojado de Lisboa (20°27’S, 44°00’W), Jeceaba, Minas Gerais, 11 Jun 1996, C.B.M. Alves et al. MZUSP 73671 (3, 216.3- 375 mm SL), Rio Cipó , tributary of Rio das Velhas, Presidente Juscelino , Minas Gerais, 19 Jun 1999, C.B.M. Alves. MZUSP 73850 (1, 315 mm SL), Rio Paraopeba , tributary of Rio São Fransico, Curvelo , Minas Gerais, Oct 1998, C.B.M. Alves. MZUSP 78509 (1, 164 mm SL), Rio Paraopeba , tributary of Rio São Francisco, Curvelo , Minas Gerais, C.B.M. Alves. MZUSP 78510 (2, 245- 250 mm SL), Rio Paraopeba , tributary of Rio São Fransico, Juatuba , Minas Gerais, 2001, C.B.M. Alves. MZUSP 83661 (1, 290 mm SL), Fish Market, Barra, Bahia, 11 Apr 2001, Expedição Jalapão. MZUSP 88290 (1, 207 mm SL), Fish Market, Barra, Bahia, 11 Apr 2001, Expedição Jalapão. MZUSP 90829 (5, 44.5-67.6 mm SL), Lagoa Peri-Peri, Rio das Velhas basin (17°26’14”S, 44°43’41”W), Várzea da Palma, Minas Gerais, 21 Apr 2005, C.B. Mascarenhas & P. Pompeu. MZUSP 94644 (1, 109 mm SL), Marginal lagoon of the Rio São Fransico (15°05’59”S, 44°03’58”W), Itacarambi, Minas Gerais, 10 May 2007, O. T. Oyakawa et al. MZUSP 95002 (1, 135.4 mm SL), Marginal lagoon of Rio São Francisco (15°05’59”S, 44°03’58”W), Itacarambi, Minas Gerais, 10 May 2007, O. T. Oyakawa et al. MZUSP 96280 (5, 30.6-37.4 mm SL), Estação de Piscicultura da CODEVASF, Três Marias, Minas Gerais, 04 Oct 2007, O. T. Oyakawa et al. MZUSP 96278 (45, 10-32.6 mm SL), Estação de Piscicultura da CODEVASF, Três Marias, Minas Gerais, 04 Oct 2007, O. T. Oyakawa et al. MZUSP 96279 (18, 20.7-26.3 mm SL), Estação de Piscicultura da CODEVASF, Três Marias, Minas Gerais, 04 Oct 2007, O. T. Oyakawa et al. MZUSP 108727 (2, 189- 295 mm SL), Rio São Francisco , at Represa de Três Marias, Minas Gerais, 14-18 Feb 1965, H.A. Britski & I.A. Dias. MZUSP 107838 (2, 129.2- 151.8 mm SL), Pedrinhas, Petrolina, Pernambuco, 19 Aug 1976, C. Souza. NMW 68181 (2, 109.2- 240.7 mm SL), Rio São Francisco. NMW 69575 (1, 118.6 mm SL), Rio São Francisco. Rio Parnaíba basin ( Brazil): MCZ 20477 (2, 92.2-113.1 mm SL), Rio Puty (c. 05°05’S, 42°49’W), Theresina, Piauí, O. St. John. MCZ 20476 (2, 151.8- 156.8 mm SL), Rio Puty (c. 05°05’S, 42°49’W), Theresina, Piauí, O. St. John. MCZ 20479 (1, 169.5 mm SL), Rio Puty (c. 05°05’S, 42°49’W), Theresina, Piauí, O. St. John. MCZ 20481 (1, 155.5 mm SL), Rio Parnaíba at Amarante (c. 06°14’S, 42°05’W) [originally labeled as San Gonçallo], Dec 1865, O. St. John. MZUSP 5099 (2, 98.2-104 mm SL), Rio Parnaíba, Teresina , Piauí, 19-22 Jun 1966, Excursão do Departamento de Zoologia da Secretaria de Agricultura do Estado de São Paulo. MZUSP 107838 (2, 130- 152 mm SL), Pedrinhas, Petrolina, Pernambuco, 29 Aug 1976, C. de Souza. NMW 69576 (1, 192.3 mm SL), rio Parnaíba, Teresina, Piauí, 1903, Brazilian Expedition. UFPB 7042 (6, 100.7- 150.5 mm SL), Rio Parnaibinha , above Ponte Nova, Alto Parnaíba, Maranhão, 06 Feb 2009. Other river basins: MNHN A8620 (paralectotype of Leporinus bimaculatus , 334.5 mm SL), Tocantins à San-Juáo das Duas Barras (= Rio Tocantins em São João das Duas Barras ), Castelnau [locality probably wrong, see Discussion].

Diagnosis: Leporinus obtusidens is distinguished from most congeners, except L. amblyrhynchus , L. conirostris , L. desmotes , L. despaxi , L. elongatus , L. jatuncochi , L. macrocephalus , L. muyscorum , L. piavussu sp. nov., L. reinhardti , L. trifasciatus and L. wolfei , by having three teeth on each premaxilla and dentary (tooth formula 3/3; vs. tooth formulae 3/4, 4/4 or 4/3). Leporinus obtusidens is distinguished from L. amblyrhynchus , L. conirostris , L. desmotes , L. despaxi , L. jatuncochi , L. macrocephalus , L. muyscorum , L. reinhardti , L. trifasciatus and L. wolfei by having three dark rounded blotches on the body and dark transverse bars usually persistent in large specimens (vs. body with a dark midlateral stripe in L. amblyrhynchus , and L. despaxi ; transverse dark bands in L. desmotes and L. jatuncochii ; body pale except for a single dark blotch on the caudal peduncle in L. conirostris ; first blotch, below the dorsal fin, transversely elongated in L. macrocephalus , L. trifasciatus and L. wolfei ; transverse bars faded in large specimens of L. muyscorum ; and the blotch on the caudal peduncle longitudinally elongated, not rounded, sometimes making contact with the second blotch in L. reinhardti ). Leporinus obtusidens is further distinguished from L. muyscorum by having six or seven scale rows between lateral line and dorsal-fin origin (vs. five). Leporinus obtusidens is distinguished from L. elongatus by having 16 scales rows around the caudal peduncle (vs. 12). Leporinus obtusidens is especially similar to L. piavussu from which it differs by having 41 to 43, rarely 44 perforated scales in the lateral line (vs. 39 to 40, rarely 41). Individuals of Leporinus obtusidens from the upper Rio Paraná basin particularly discriminate from individuals of L. piavussu by having mouth directed somewhat or entirely downward, its cleft at horizontal through ventral orbital margin or slightly below (vs. mouth terminal, its cleft above horizontal through ventral orbital margin).

Description: Morphometrics from type specimens are given in Table 2 and from non-type specimens in Table 3 and 4. Large sized species (largest examined specimen 510 mm SL). Body somewhat elongate, moderately compressed, greatest body depth at dorsal-fin origin. Dorsal profile gently convex from snout tip to dorsal-fin origin; slightly convex along dorsal-fin base; straight from posterior end of dorsal-fin base to adipose-fin origin, and concave from that point to origin of dorsal procurrent caudal-fin rays. Ventral profile gently convex from lower lip to vertical through pectoral-fin origin; convex from later point to anal-fin origin; somewhat straight along anal-fin base, and concave from anal-fin end to origin of ventral procurrent caudal-fin rays.

Head slightly elongated, snout moderately to extremely elongate. Mouth terminal (in individuals of 150 mm SL or less) to subterminal (in individuals of more than 150 mm SL), its cleft at level with ventral border of eye or slightly below. Upper jaw extending slightly anteriorly beyond lower jaw. Posterior end of maxilla approximately at vertical through posterior margin of anterior nostril. Premaxillary with three teeth gradually decreasing in size from symphyseal tooth. Dentary with three teeth also gradually decreasing in size from symphyseal tooth ( Fig. 11 ).

First gill arch with 11 (2), 12 (7) or 13 (6) gill rakers on lower limb, 1 (15) gill raker at angle, and 10 (10), or 11 (5) on upper limb.

Scales cycloid, five to eight radii. Lateral line with 41* (40), 42 (116), 43 (34) or rarely 44 (4) perforated scales, extending from posterior margin of opercle to base of median caudal-fin rays. Horizontal scale rows between dorsal-fin origin and lateral line 6* (170) or 7 (29). Horizontal scale rows between lateral line and pelvic-fin origin 5 (6), 5.5 (58), 6* (131), 6.5 (3) or 7 (1). Horizontal scale rows around caudal peduncle (circumpeduncular scale series) 16 (36). Predorsal scales from dorsal-fin origin to tip of supraoccipital spine 11 (6), 12 (74), 13 (22) or 14 (5). Dorsal scales from dorsal-fin end to adipose-fin origin 11 (1), 12 (20), 13 (43), 14 (43) or 15 (3). Dorsal scales between adipose-fin end and first dorsal procurrent caudal-fin ray 8 (14), 9 (35), 10 (32) or 11 (5). Prepelvic scales 17 (3), 18 (11), 19 (27), 20 (33) or 21 (21). Scales from base of pelvic fin to anus 8 (9), 9 (34), 10 (29) or 11 (7). Scales between anus and anal-fin origin 1 (12) or 2 (74). Scales between anal-fin end and first procurrent caudal-fin ray 7 (4), 8 (6) or 9 (56), 10 (22), 11 (4) or 12 (1). Base of anal-fin rays covered by a row of four to six small scales.

Dorsal-fin rays ii,9 (1) or ii,10 (110). Dorsal-fin origin between the middle of distance between snout tip and posterior border of adipose fin, and the middle of distance between snout tip and the middle of caudal peduncle, and at vertical through second or third scale in front of pelvic-fin origin. Dorsal-fin distal margin straight or gently convex. Last dorsal-fin ray split to its base (counted as a single element). Adipose fin small, its origin at vertical through middle of anal-fin base, or slightly posterior. Pectoral-fin rays i,14 (8), i,15 (36), i,16 (59), i,17 (65) or i,18 (9). Tip of pectoral-fin rays extending to first to fourth scale in front of pelvic-fin origin (never reaching the latter). Pelvic-fin rays i,8 (110), rarely i,7 (1) or i,9 (2). Pelvic-fin origin at vertical through base of first to fourth branched dorsal-fn ray. Tip of pelvic fin reaching fifth to third scales in front of anus. Anal-fin rays ii,8 (62), iii,8 (47), or ii,9 (2); its origin at vertical through fourth to sixth scale in front of adipose fin. Distal margin of anal fin concave. Anteriormost branched anal-fin ray about three times longer than posteriormost ray. Last anal-fin ray usually split to its base (counted as a single element). Principal caudal-fin rays i,8,9,i (35). Caudal fin forked, with lobes approximately similar in size or upper lobe slightly longer than lower lobe. Vertebrae 39 (3).

Coloration: Ground color light beige to light brown, darker dorsally. Three dark blotches on sides of body over lateral line, first below dorsal-fin base, second below space between dorsal-fin base and adipose-fin origin and third at the posterior portion of caudal peduncle. Eight transverse dark bars on dorsal and lateral portions of body, bifurcated dorsally; bars very conspicuous and extending ventrally, in specimens of 100 mm SL or less, becoming slightly faded in larger specimens, and disappearing completely in some individuals. Scales of lateral areas of body with disperse chormatophores, more concentrated on its free margins. Fins nearly hyaline, with chromatophores tiny and scattered. Dorsal, adipose and caudal fins slightly darker than pectoral, pelvic and anal fins.

Live specimens ( Figs. 9 and 10 ) with head and body silver to tan, dorsal fin greyish, pectoral, pelvic, anal and caudal fins dark yellow, or sometimes orange or reddish yellow (reddish yellow especially for specimens from the Rio São Francisco ). Caudal fin with dark dorsal and ventral margins. Midlateral blotches and transverse bars sometimes faded.

Distribution: Leporinus obtusidens , described from the Río de La Plata at Buenos Aires, is commonly found in the lower and middle Rio Paraná basin ( Argentina, Brazil, Uruguay, and Paraguay), Rio Uruguay basin ( Argentina, Uruguay, and Brazil), Rio Paraguay basin ( Argentina, Brazil, and Paraguay), upper Rio Paraná basin ( Brazil), Rio Guaíba in Rio Grande do Sul ( Brazil) and Rio São Francisco ( Brazil) ( Fig. 4 ). Specimens of Leporinus obtusidens from the Rio São Francisco were introduced in rivers and reservoirs in northeastern Brazil (e.g., Fontenelle & Vasconcelos, 1977) but we do not know the exact extension of these introductions. On the other hand, the occurrence of Leporinus obtusidens in the Rio Parnaíba basin seems to be natural, as some specimens were collected there in 1865, by the Thayer Expedition.

Ecology: Leporinus obtusidens lives in medium to large rivers accomplishing very long reproductive and feeding migration in rivers of the Paraná basin ( Godoy, 1975). Leporinus obtusidens is a large-sized species very important in recreational, subsistence and commercial fishing, and has been included in Brazilian fishery statistics since before the middle of last century (e.g., Schubart, 1943; Godoy, 1975).

Common names: “Boga” or “bogón” in Argentina, “piava” in the Rio Guaíba basin (states of Rio Grande do Sul and Santa Catarina, in Brazil), “piapara ” in the upper Rio Paraná basin (states of São Paulo , Paraná, Mato Grosso do Sul, Goiás, and Minas Gerais, in Brazil), “piau ” or “piapara ” in the upper and middle Río Paraguay basin (State of Mato Grosso, in Brazil), “piau-verdadeiro” in the Rio São Francisco basin (states of Minas Gerais, Bahia, Pernambuco, in Brazil) and other northeastern Brazilian rivers.

Remarks: Lütken (1875) studied specimens from the Rio São Francisco basin to make a detailed redescription of Leporinus elongatus (= L. obtusidens ). Steindachner (1875) also mentioned this species from the Rio São Francisco. Since then, following those authors, the “piau-verdadeiro” from the Rio São Francisco basin that has been identified as Leporinus elongatus should now necessarily be ascribed to L. obtusidens . The “piau-verdadeiro” was also introduced in rivers of northeastern Brazil and the scientific name Leporinus elongatus has appeared in papers referring to introduction and fishery in the region (e.g., Fontenelle & Vasconcelos, 1977). On the other hand, the species collected in the Rio Guaíba basin and commonly named “piava” has been usually and correctly identified as Leporinus obtusidens since Hensel (1870) and von Ihering (1893, 1897) (see also Malabarba, 1989).

Boulenger (1897) described Leporinus silvestrii based on one specimen (holotype) from the Rio Coxipó a tributary of the Rio Cuiabá (upper Rio Paraguay basin). All meristic and morphometric features of the holotype of Leporinus silvestrii , as well as of all examined specimens from the upper Paraguay basin, fall within the range of L. obtusidens . Therefore, Boulenger’s species is herein considered a junior synonymy of L. obtusidens .

Fowler (1941) described Leporinus piau based on three lots: ANSP 69502, holotype from Rio Salgado , Ceará; ANSP 69503-7, paratypes from Rio São Francisco , Pernambuco; and ANSP 69509, paratypes from rio Jaguaribe, Ceará. Fowler (1941:176) mentioned that the common names for his species were “piaus” and “piau-verdadeiro”. The examination of the all aforementioned type specimens revealed that only ANSP 69503-7 are actually Leporinus obtusidens , and that probably the common name “piau-verdadeiro” came from those specimens, corroborating our other observations. The holotype and other paratypes of Leporinus piau are in fact not conspecific with L. obtusidens .

Campos (1945a) described Leporinus aguapeiensis based on one specimen ( MZUSP 3040, 210 mm SL) from the Rio Aguapeí , a tributary of the Rio Tietê in the state of São Paulo (upper Rio Paraná basin). The species was briefly described, and after that only mentioned in fish catalogs. Britski (1969), in a list of type specimens from the MZUSP, provided some features of the presumed holotype of Leporinus aguapeiensis , some of them disagreeing with those of the original description. Our more comprehensive examination of this presumed holotype provided information for asserting that the specimen in the jar with the number MZUSP 3040 actually is not the holotype of Leporinus aguapeiensis described by Campos (1945a). The specimen now in the jar is smaller (188 mm SL) than Campos’s description (210 mm SL), has 39 lateral-line scales (vs. 41 in Campos’s description), five rows of scales between the lateral line and the dorsal-fin origin (vs. six in Campos’s description and text figure), and some other details of body proportions, characteristics of fins, and general aspect that differ from the specimen illustrated by Campos (1945a: text figure). These data lead to the conclusion that the holotype of Leporinus aguapeiensis is corrently lost and the jar with the catalog number MZUSP 3040 holds now a specimen of Leporinus piavussu described in this paper. Furthermore, according to the description and illustration given by Campos (1945a), including the presence of 41 lateral-line scales and mouth directed downward, its cleft at the horizontal through inferior orbital margin, Leporinus aguapeiensis is a synonym of L. obtusidens .

Campos published two papers citing and describing various species of Leporinus ( Campos, 1945 a, 1945b). These publications are characterized by many mistakes in species identification and by descriptions not entirely based on specimens the author examined but also on data from the literature, sometimes mingled in an unintelligible way. To complicate the situation, most of the lots mentioned by Campos disappeared from the MZUSP collection, where they were originally deposited. In the present contribution, we correct the identification of part of the specimens mentioned in Campos’s papers. A complete revision of her two papers will be published in a separate contribution.

Variation in the coloration of the fins in live specimens is observed among different populations of Leporinus obtusidens . As reported by several authors (e.g., Casciotta et al., 2005) the specimens from the lower Rio Paraná, Rio Uruguay and Rio Paraguay basins have yellow to orange pectoral, pelvic, anal and caudal fins. Specimens from the upper Rio Paraná basin have yellow fins ( Godoy, 1975). On the other hand, Reinhardt (in Lütken, 1875:197), described specimens from the Rio São Franscisco as having bright red pectoral, pelvic, anal and caudal fins. This kind of variation of red and yellow pigments on body and fins, according to the geographical distribution is found in other anostomid species and seems to be influenced by environmental factors. This is the case of Synaptolaemus latofasciatus , an anostomid recently studied by us ( Britski et al., 2011), whose populations in different river basins present light bars along the body varying from red to orange and yellow alternating with dark ones.

Braga (1992:34) reported specimens from Argentina with 45 perforated scales on the lateral line, none of the 89 specimens we examined from that area have that number. If Braga’s datum is correct, this number of perforated scales on the lateral line (45) should be extremely exceptional or is present in anomalous individuals .

The specimen mentioned by Valenciennes (in Cuvier & Valenciennes, 1850), i.e., MNHN 8622, is not Leporinus obtusidens , but possible L. reinhardti . Günther (1864) identified a specimen of “piau-verdadeiro” from Rio Cipó ( Rio São Francisco basin) as L. pachyurus . Günther’s identification was subsequently corrected by Lütken (1874) to Leporinus elongatus (= L. obtusidens ). Steindachner (1875:216) considered Leporinus pachyurus as a possible synonym of L. elongatus (= L. obtusidens ), but he cautiously added an interrogation mark before the name of the species, indicating that he was not sure.

Figures

FIGURE 4: Distribution map of Leporinus elongatus (yellow triangles), L. obtusidens (white squares), and L. piavussu (red circles).

FIGURE 7: (A) Holotype of Leporinus obtusidens, MNHN 1693, 209.0 mm SL; (B) paralectotype of L. elongatus, MNHN 9800, 256.0 mm SL; (C) holotype of L. silvestrii, BMNH 1902.2.10.32, 150.0 mm SL.

FIGURE 8: Leporinus obtusidens: (A) MZUSP 78509, 170.0 mm SL, Rio São Francisco, (B) MZUSP 41577, 192.0 mm SL, Rio Paraguay, (C) MZUSP 48820, 278.2 mm SL, upper Rio Paraná; (D) MZUSP 48700, 85.4 mm SL, upper Rio Paraná.

FIGURE 9: Leporinus obtusidens, photographed live: (A) collected in the Ribeirão Salitre, tributary of Rio Paranaíba, Minas Gerais, upper Rio Paraná basin (photo by Luiz Fernando Salvador Jr.), (B) collected in the Rio Paraopeba, Rio São Francisco basin, Belo Vale, Minas Gerais (photo by Rafael Magno).

FIGURE 10: Leporinus obtusidens, photographed live in the rio Cipó (photo by Luiz Fernando Salvador Jr.).

FIGURE 11: Anterior portion of head of Leporinus obtusidens, MZUSP 105067, 390.0 mm SL. Scale bar equals 10 mm.