Brycon falcatus Müller & Troschel, 1844

Lima, Flávio C. T., 2017, A revision of the cis-andean species of the genus Brycon Müller & Troschel (Characiformes: Characidae), Zootaxa 4222 (1), pp. 1-189 : 142-158

Brycon falcatus Müller & Troschel, 1844

( Figs. 84–98 )

Chalceus labrosus Jardine, in Jardine & Schomburgk, 1841: 212 –213, pl. 13, fig. 1 (Type locality, “river Paduiri”); Lima, 2003: 178 (listed; as a species inquirendae in Brycon ; type locality incorrectly stated as situated in Guyana).

Brycon falcatus Müller & Troschel, 1844: 90 (Type locality, “In Guiana et Surinam”); Müller & Troschel, 1845: 29, pl. 6, fig. 1 (redescription); Müller & Troschel in Schomburgk, 1848: 635 (“allen flüssen von Britisch-Guiana”; common name); Günther, 1864: 334 –335 (Guyana; Essequibo River; Suriname); Goeldi, 1898: 483 (common name, rio Capim, Brazil); Eigenmann, 1912: 371 –372 (Guyana: Essequibo River at Rockstone; Potaro River at Tukeit); Fowler, 1914: 250 (Rupununi River, Guyana); Cockerell, 1915: 100, pl. 26, fig. 6 (scale morphology; Guyana); Steindachner, 1917: 36 –37 (Albina, Suriname; Brasil, Roraima: Rio Surumú, Serra do Mello; Rio Branco, Bem Querer; Boa Vista; Serra Grande; Conceição; Amazonas: mouth of rio Negro); Géry, 1964: 450 (diagnosis in key); Lowe-McConnell, 1964: 115, 118, 120, 127, 132 (Rupununi and Ireng rivers, Guyana; natural history); Richter & Nijssen, 1980: 123, 125 (Brokopondo reservoir, Suriname River, Suriname; occurrence; abundance, common name); Howes, 1982: 26 –29, fig. 18 (Guyana: Essequibo River; Tukeit; upper Cuyuni River; Rupununi district; Suriname: Nickerie district); Vari, 1983: 12, 16, figs. 3, 13, 14 (branchial arches morphology); Lasso, 1992: 11, 22, fig. 2 (río Suapure, Serranía de Los Pijiguaos, Venezuela); Planquette et al., 1996: 226 –227, fig. (French Guiana, Maroni and Mana rivers); Hardman et al., 2002: 234 (Essequibo and lower Potaro Rivers, Guyana); Mol, 2002: 71 (Kwitaro and Rewa Rivers, Rupununi, Guyana); Lima, 2003: 176 (synonymic list; primary type material; distribution; common names; maximum size); Hoeinghaus et al., 2003: 383 (Río Cinaruco, Rio Orinoco basin, Venezuela); Arrington & Winemiller, 2003: 449, 456 (Río Cinaruco, Río Orinoco basin, Venezuela; sandbank use); Watkins et al., 2004: 46 (Burro-Burro, Siparuni and Essequibo Rivers, Iwokrama forest, Guyana); Layman et al., 2005: 2532 (Río Cinaruco, Río Orinoco basin, Venezuela; trophic position in relation to size); Bejarano et al., 2006: 362, 365, 367–368 (Río Mesay, Río Caquetá drainage, Colombia: abundance); Blanco-Parra & Bejarano-Rodríguez, 2006: 856 –857 (Río Mesay, Río Caquetá drainage, Colombia: diet, reproduction); Mol et al., 2006: 114 (Coppename and Rechter River, Suriname); Mol et al., 2007: 355, 365 (Suriname River, Brokopondo reservoir, Suriname; abundance before and after impoundment); Agostinho et al., 2007: 126 –127 (Lajeado Dam, rio Tocantins, Tocantins, Brazil; density in fish ladder); Agostinho et al., 2007: 163 –165 (Lajeado Dam, rio Tocantins, Tocantins, Brazil; presence in the fish ladder); Silva et al., 2007: 487 (Rio das Mortes, rio Araguaia basin, Mato Grosso, Brazil); Ferreira et al., 2007: 125 (picture; rio Branco, Roraima); Albrecht et al., 2009: 181 –191 (Serra da Mesa dam, upper rio Tocantins basin, Brazil; weight-length relationships, reproduction, diet, persistence in the reservoir); Melo et al., 2009: 424 (Rio das Mortes, rio Araguaia basin, Mato Grosso, Brazil); Camargo & Giarrizzo, 2009: 221, 227 (lower rio Xingu: biological parameters, estimated biomass); Antunes et al., 2010: 676, 679–628 (Lajeado Dam, rio Tocantins, Tocantins, Brazil; nuclear and mitochondrial DNA analysis); Lima & Ribeiro, 2011: 149 (as an example of “Shield” distribution pattern); Venere & Garutti, 2011: 64 (Brazil, Mato Grosso, Parque Estadual da Serra Azul, rio Araguaia basin; short description, photo); Mol et al., 2012: 270 (Suriname: occurrence in Corantijn, Nickerie, Coppename, Saramacca, Suriname, and Marowijne rivers); Mol, 2012: 23, 283–285 (ocurrence in Suriname, local name, photos); Bartolette et al., 2012: 61 (Brazil, Goiás, Serra da Mesa dam); Albrecht et al., 2012: 203, 205 (Brazil, Goiás, Serra da Mesa dam; trophic analysis); Rubio et al., 2012: 173 –182 (Mato Grosso, rio Guaporé: population structure, female maturity, size, age); Pelicice & Agostinho, 2012: 711 (Brazil Tocantins, Peixe Angical dam fish ladder); Lima et al., 2013: 228 –229 (Brazil, Rondônia, rio Madeira basin; distribution in the rio Madeira basin, short description, photo); Correa & Winemiller, 2014: 214, 217, 218, 219, 220, 221 (Colombia, Depto.Vaupés, Río Apaporis: seasonal variation in diet, diet breadth and overlap with other frugivore fishes); Matos et al., 2016: 2016: 1–6 (diet, impact of artificial food supply in wild specimens; Brazil, rio Teles Pires basin). [Doubtful records: Gilbert & Roberts, 1971: 26 (Ecuador, Amazon basin); Saul, 1975: 103 (Ecuador, Napo, Río Conejo, Río Putumayo basin)].

Brycon schomburgkii Müller & Troschel, 1844: 91 (Type locality, “In Guiana”); Müller & Troschel, 1845: 29, pl. 6, fig. 2 (redescription); Müller & Troschel in Schomburgk, 1848: 635 (lower Essequibo River); Eigenmann, 1912: 372 (synonymization with B. falcatus ).

Brycon hilarii (not Valenciennes, 1850): Valenciennes (in Cuvier & Valenciennes, 1850): 248 (part; “l’Amazone”; syntypes of Chalceus hilarii ); Castelnau, 1855: 68, pl. 36, fig. 1 (Brazil. Goiás, “Salinas”); Géry & Mahnert, 1992: 815 (part; paralectotypes from “Salinas”); Lima, 2003: 176 (type material; referred as putative specimens of Brycon falcatus ).

Brycon brevicauda Günther, 1864: 335 (Type locality, “Rio Jocintins, River Capin”); Boulenger, 1897a: 297 (Brazil, Pará, Ilha de Marajó); Goeldi, 1898: 483 (common name; upper rio Tapajós basin); Géry, 1964: 448, 450, pl. 2, fig. a (Ilha do Bananal, rio Araguaia; diagnosis); Costi et al., 1977: 53, fig. 23 (Pará, at the confluence of rio Araguaia and rio Tocantins); Santos et al., 1984: 41 –42, photo (Pará, rio Tocantins); Lowe-McConnell, 1991: (Mato Grosso, Xavantina: rio das Mortes, rio Araguaia basin; “Sangadina stream”; rio Suiá-Missú, rio Xingu basin); Tejerina-Garro et al., 1998: 402 (Goiás, São Miguel do Araguaia, floodplain lakes; relative abundance); Bergleiter, 1999: 23, 29, 48, 74–75, 113–114, 149 (pl. 10) (Lower rio Xingu, between Porto de Moz and Souzel; diet, feeding habits, social behavior, visual communication); Lima, 2003: 176 (type material; as a synonym of Brycon falcatus ); Iglesias-Rios, 2012: 326 (Brazil, Goiás, Serra da Mesa dam: impacts of damming).

Brycon bicolor Pellegrin, 1909a: 12 –13 (Type locality, “Orénoque”); Howes, 1982: 11, 13–14, fig.8 (syntypes, redescription); Taphorn, 1992: 80 –81, 128–130, figs. (Río Apure basin, Venezuela; description, ecology, biology); Royero et al., 1992: 49 (Rio Atabapo, Territorio Federal Amazonas, Venezuela); Machado-Allison et al., 1993: 66, 69 (Rio Aguaro and Rio Guariquito, Estado Guarico, rio Orinoco basin, Venezuela); Lima, 2003: 175 (type material; as a possible synonym of Brycon melanopterus ).

Brycon stübelli Steindachner, 1882a: 176 (Type locality, “Amazonenstome”; brief description); Steindachner, 1882b: 13, pl. 1, fig. 1 (full description; type locality specified as “Rio Amazonas (Iquitos)”). [not Amaral Campos, 1950: 142]

Characinus amazonicus (not Agassiz, in Spix & Agassiz): Magalhães, 1931: 141 –142 (Lower Amazon basin; Goiás; natural history, common name).

Brycon matrinchao Fowler, 1941: 192 –194, fig. 102 (Type locality, “Rio Parnahyba, Therezina, Piauhy”); Géry, 1964: 450 (diagnosis in key).

Brycon melanopterus: Myers & Weitzman, 1960: 99 , 101–102 (Los Micos, Cordillera Macarena, 3°20´S 73°56´W, Río Guaviare, rio Orenoco basin, Colombia); Lima et al., 2005: 164 (Rio Tiquié, upper rio Negro basin, Brazil; description, natural history, figure, common indigenous names).

Brycon stuebeli: Géry, 1964: 450 (diagnosis in key).

Brycon stubelii: Howes, 1982: 45 (comments).

Brycon cf. falcatus: Goulding et al., 1988: 124 (Middle and lower rio Negro basin; occurrence).

Brycon sp. ( aff. bicolor ): Géry & Mahnert, 1992: 800 –802 (Rio Aripuanã, Ilha do Castanhal).

Brycon sp. ( B. falcatus group): Toledo-Piza, 2002: 116 –117 (drawing by A.R. Wallace; “ Rio Uaupés”; common name).

Brycon carpophagus (not Valenciennes): Mérona et al., 2001: 387, 391 (Rio Tocantins, Tucuruí; diet before and after river impoundment).

Brycon stuebelli: Zarske, 2003: 16 , fig. 7 (holotype, MTDF 380); Lima, 2003: 176 (type material; as a synonym of Brycon falcatus ).

Brycon falcatus group: Phillip et al., 2013: 8, 16 ( Trinidad southern coast; occurrence as a vagrant species).

Diagnosis. Brycon falcatus can be distinguished from all remaining cis-andean Brycon species, with the exception of B. gouldingi , by typically possessing a V- or crescent-shaped dark blotch on caudal peduncle and caudal fin. Brycon falcatus can be distinguished from B. gouldingi by possessing possessing dark, longitudinal stripes formed by pigmentation concentrated on the mid-distal portion of scales (vs. dark, wavy longitudinal stripes formed by dark pigment concentrated on upper and lower scale margins), paired fins typically clear (vs. paired fins black), and lower lateral line scale counts (47–69, modally 57, vs. 66–82, modally 74). Brycon falcatus is morphologically more similar to B. melanopterus , and an unequivocal diagnosis between both species based only on external morphological characters is not possible due to the great polymorphism in color pattern observed in the species. However, typically, Brycon falcatus does not present an oblique dark solid stripe, presenting instead a V or crescent-shaped blotch on caudal fin (vs. black pigmentation restricted to the upper caudal-fin lobe in B. melanopterus ). In addition, Brycon falcatus is typically a higher bodied fish, with higher vertebrae counts. See the item “Comparisons” under Brycon melanopterus , and the item “Variation”, below, for thorough account on the subject.

Description. Morphometric data are presented in Tables 21–22 ; some meristic data (lateral line counts and scales between dorsal-fin origin and lateral line) in Tables 23–24 . Middle- to large-sized species, largest examined specimen 434.7 mm SL. Body moderately slender to high. Largest body height slightly ahead of dorsal-fin origin. Dorsal body profile slightly convex from upper lip margin to vertical through anterior naris, straight to moderately convex from latter point to basis of supraoccipital process, moderately to pronouncedly convex from latter point to dorsal-fin origin, straight along dorsal-fin basis, and straight to slightly convex from dorsal-fin basis to adipose-fin origin. Dorsal profile of caudal peduncle slightly concave. Ventral profile slightly to pronouncedly convex from lower lip to pelvic-fin insertion, straight to slightly convex from this point to anal-fin origin and approximately straight along anal-fin base. Ventral profile of caudal peduncle slightly concave.

Head profile slightly acute anteriorly, snout obtuse, mouth terminal. Jaws approximately isognathous to slightly anisognathous, outer row of premaxillary teeth partially exposed when mouth is closed. Maxillary moderately long, extending posteriorly to anterior third of pupil. Adipose eyelid well developed. Premaxillary teeth in three rows; teeth of third row largest.

Five (2), 6 (5), 7 (29), 8 (65), 9 (118), 10 (99), 11 (53), 12 (8), or 13 (1) relatively small tricuspidate teeth in outer series. Three (30), 4 (229), 5 (107), 6 (6), or 7 (1) tri- to pentacuspidate teeth in second, inner premaxillary row, plus 2 (2), 3 (150), 4 (218), or 5 (7) tricuspidate teeth between the first and third rows. Two teeth in third premaxillary row, medial teeth largest, symphyseal teeth smaller, slightly tilted towards each other, both pentacuspidate. Maxillary margins approximately parallel, straight in profile. Fifteen to 28 maxillary teeth, slightly smaller than teeth of first premaxillary row, anterior teeth tricuspidate, posterior teeth unicuspidate. Dentary with 7 (7), 8 (34), 9 (72), 10 (61), 11 (26), 12 (9), 13 (3), 14 (1), or 15 (1) teeth in main series. Anterior four dentary teeth assymetrical, considerably larger and bulkier than remaining teeth, pentacuspidate, each with central cusp distinctly larger than remaining cusps. Remaining dentary teeth progressivelly smaller, penta- to unicuspidate. Inner (lingual) series consisting of a small, single unicuspid symphyseal tooth, situated immediately posterior to symphyseal dentary teeth of main series, plus row of 13–21 small, aciculated, unicuspidate teeth, originating on lingual crest of dentary replacement trench at the level of fourth to seventh main series dentary teeth. Symphyseal teeth may be lacking in larger (> 350 mm SL) specimens.

Scales cycloid. Lateral line complete, from supracleithrum to caudal-fin base. Forty-seven (1), 48 (1), 49 (1), 50 (3), 51 (11), 52 (25), 53 (57), 54 (59), 55 (77), 56 (90), 57 (104), 58 (93), 59 (57), 60 (49), 61 (27), 62 (14), 63 (8), 64 (16), 67 (1), or 69 (1) scales in lateral line series. Laterosensory tube simple in specimens smaller than 100 mm SL, ramified in specimens larger than 100 mm SL. Tubules ramification increasing in complexity along ontogeny, specimens up to 150 mm SL with tubules with two or three branches, three to six branches in specimens between 150–250 mm SL, and with more than 10 branches and developing a dendritic pattern of ramification, with tubules often overlapping each other in larger (> 270 mm SL) specimens. Horizontal scale rows between dorsal-fin origin and lateral line eight (1), 9 (21), 10 (115), 11 (122), 12 (103), 13 (29), or 14 (3). Horizontal scale rows between lateral line and pelvic-fin 4 (21), 5 (156), 6 (169), 7 (27), or 8 (1). Circumpeduncular scales 15 (1), 16 (27), 17 (75), 18 (125), 19 (67), 20 (51), 21 (32), or 22 (6).

Dorsal-fin rays ii, 9. Dorsal fin origin slightly ahead, or about at middle of SL. First dorsal-fin pterygiophore inserting behind neural spine of 11th (2), 12th (1), or 13th(1) vertebra. Anal-fin rays iii (not including first, small unbranched ray only visible in cs specimens), 18 (1), 19 (4), 20 (11), 21 (41), 22 (90), 23 (93), 24 (82), 25 (45), or 26 (6). First anal-fin pterygiophore inserting behind haemal spine of 22th (4), or 23th (1) vertebrae. Anal-fin rays decreasing only slightly in size towards anal-fin end. Anal fin displaying several (c. 5–12 per fin-ray main branch) small hooks on posterior main branch of branched rays 2–11, associated with dense, gelatinous tissue in 5 examined specimens (MZUSP 3845, 2, 196.2– 198.9 mm SL, MZUSP 16448, 1, 196.5 mm SL mm SL, MZUSP 91493, 1, 226.0 mm SL, MZUSP 94990, 1, 230.0 mm SL). A single hook per ray segment. Sheath of scales covering basis of anal-fin rays composed of four scale rows, lower scale row formed by 21–25 rectangular scales. Pectoral-fin rays 11 (3), 12 (76), 13 (229), or 14 (58). Pelvic-fin rays typically i, 7 (364), rarely i, 6 (4), or i, 8 (4). Main caudal-fin rays 10/9. Caudal fin forked, lobes slightly emarginated. Laterosensory tube extending over interradial membrane between upper and lower caudal-fin lobes to the distal portion of fin. Laterosensory tube on caudal fin with dorsally and ventrally oriented side branches across its length. Small distal projection in the area of the laterosensory tube present in specimens with relatively intact caudal fin.

Four branchiostegal rays, three on anterior ceratohyal and one on posterior ceratohyal. First branchial arch with 12 (14), 13 (24), 14 (40), 15 (32), 16 (22), or 17 (2) lower, 1 at angle, and 11 (1), 12 (15), 13 (38), 14 (51), 15 (20), 16 (6), or 17 (2) upper gill rakers. Vertebrae 39 (1), 40 (1), 41 (7), 42 (5), 43 (2), or 44 (1). Supraneurals 8(2), or 9 (2).

Coloration in alcohol. Top of head, snout, supraorbital, and sixth infraorbital light-grey to light-brown. Dorsal portion of body light-grey to dark-brown. Second, third, fourth, and fifth infraorbitals, opercle and cleithrum silvery in specimens retaining guanine, light-brown in specimens that lost this pigment due to a long storage in formalin. Dentary, maxillary, gular area, and lower portion of body light-brown. Lateral portion of body silvery in specimens retaining guanine, light brown in specimens that lost this pigment due to a long storage in formalin. Humeral blotch present, slightly to moderately conspicuous, approximately rounded in shape, situated immediately above lateral line, its anterior margin at level of second, extending longitudinally to posterior margin of fourth to fifth lateral line scales, and vertically one and half scales high. Scales on lateral portions of body with dark pigmentation concentrated on their central portion, forming dark, straight longitudinal stripes, more conspicuous dorsally. Dark, solid, oblique dark stripe extending along anal-fin scales sheath and anal-fin basis in almost all specimens (see item “Variation”, below). Caudal peduncle blotch wide, extending across upper and lower caudalfin rays typically as a V- or crescent-shaped dark blotch, though with a great degree of variation in the development of the pigmentantion in the lower caudal-fin lobe (see item “Variation”, below). Dorsal, anal, pectoral, and pelvicfin rays with a variable amount of interradial dark pigmentantion but typically clear. Adipose-fin light- to darkgrey, with scattered dark spots in large specimens from the upper rio Tapajós basin.

Color in life. Description based on pictures of several specimens collected at the lower rio Japurá (Lago Amanã), upper rio Madeira, upper rio Tapajós, upper rio Xingu ( Fig. 90 ), and rio Tocantins in Amazon basin, Río Inirida, Orinoco basin, and Kuribrong River, Essequibo basin, plus published pictures of living specimens ( Géry, 1977: 321, upper and lower; Planquette et al., 1996: 227; Ferreira et al., 2007: 125). Top of head and snout light- to dark-grey. Dorsum plumbeous. Lateral surfaces of head and body silvery. Humeral blotch relatively inconspicuous. Dark stripe extending along anal-fin basis and dark, V-shaped caudal peduncle/caudal-fin blotch very conspicuous. Distal border of caudal fin yellowish to reddish. Adipose fin yellowish grey. Remaining fins translucent, dorsal fin with some yellowish pigmentation.

Variation. Brycon falcatus is one of the most widespread cis-andean Brycon species, and perharps not unexpextedly, a great degree of variation in body shape and color pattern is observed across its range. Specific features that show a great degree of variation are body height, caudal-fin pigmentation, scale counts, maximum body size, and, to a lesser extent than the previous features, anal-fin pigmentation. Each of these features is treated sequentially below.

Body height varies considerably in specimens of Brycon falcatus , to an extent unequalled among cis-andean Brycon species. Specimens range from being relatively elongated ( Fig. 89 ) to high-bodied ( Figs. 86 , 88 , 92 ). However, there is no consistent geographical variation in this character, and most river systems present specimens ranging from both extremes in body shape. Probably, most of the observed variation in this trait is simply a result of phenotypic plasticity.

Caudal-fin pigmentation is the most significant trait to vary among Brycon falcatus populations, and, contrary to body height, exhibits a clear geographical pattern. Brycon falcatus populations from the Guianas, rio Branco, rio Capim, rio Tocantins, and rio Xingu basins possess the characteristic V- or crescent-shaped caudal-fin blotch, with the extent of dark pigmentation approximately symmetrical in both lobes ( Figs. 86–87 ). However, moving westwards into the Brazilian and Guyanese shields, dark pigmentantion on the lower caudal-fin lobe tend to decrease clinally in intensity. Specimens from the rio Tapajós and rio Madeira basins range from possessing an almost symmetrical dark pigmentation in both fin lobes ( Figs. 88 , 92 ) to a considerably less pigmented lower caudal-fin lobe. Specimens from the middle and lower rio Negro and middle and middle rio Orinoco basin possess a clearly asymmetrically pigmented caudal fin, with the dark pigmentation much more intense and extensive in the upper, than in the lower caudal-fin lobe ( Figs. 93–95 ). Moving westward into western Amazon, the apparently scattered populations of Brycon falcatus occurring in that vast area possess an even more asymmetrically pigmented caudal-fin, with the lower lobe almost ( Fig. 96 ) or completely ( Fig. 97 ) unpigmented, the latter condition found in specimens from Iquitos area, the most westward known locality for the species. Oddly, specimens from the upper rio Negro (above São Gabriel rapids) and upper rio Orinoco (above its junction with the Río Guaviare) basins present a similar color pattern to the specimens from Iquitos area, presenting no dark pigmentation at all at the lower caudal-fin lobe and the upper caudal-fin lobe pigmentation almost continuous with the anal-fin dark stripe ( Fig. 98 ). Specimens from the Iquitos area and upper rio Negro and upper Río Orinoco basins are thus very similar in color pattern to B. melanopterus , though B. falcatus is typically a higher-bodied species, with lower vertebral counts (see item “Comparisons” of B. melanopterus ). See item “Putative examples of mimicry involving Brycon ”, below, for a possible explanation for this similarity.

Scale counts vary considerably among distinct populations of Brycon falcatus , with specimens from the Guianas clearly presenting lower counts when compared with specimens from the Orinoco and Amazon basins (see Tables 23 and 24). The lower scale counts presented by Guyanese specimens when compared with specimens from rio Capim and rio Tocantins basins were the main reason supporting the recognition of Brycon brevicauda as a valid species (e.g., Géry, 1964: 450; Howes, 1982: 14). However, the examination of large series of specimens undertook during the present study demonstrated a continuous variation in scale counts among the several populations of Brycon falcatus , thus failing to confirm the presumed distinctness of B. brevicauda based on this character ( Tables 23 and 24).

Another trait which shows a clear geographical component in Brycon falcatus is the maximum length reached by different populations. Typically, Brycon falcatus is a middle-sized species, generally does not exceeding 300 mm SL (e.g., the maximum size of 350 mm TL reported by Rubio et al., 2012, based on the examination of 279 specimens collected at the rio Guaporé). However, extensive examination of both preserved and unpreserved specimens of Brycon falcatus from the rio Teles Pires and rio Juruena in the upper rio Tapajós basin, and from the upper rio Xingu basin showed that individuals belonging to these populations often grow considerably above this upper limit. Maximum recorded sizes from specimens from these areas are, respectively, 435.0 and 401.0 mm SL, and specimens ranging between 300–400 mm SL are common. To complicate further the issue, in the upper rio Tapajós area apparently both morphotypes (“ large-sized” and “middle-sized”) co-exist (J.M. Mendes and H.F. Mendes, pers. comm.). The “large-sized” population from the upper rio Xingu is slightly different from the one from the upper rio Tapajós in being on average smaller-sized and by not possessing the dotted adipose fin present in the latter.

58 59 60 61 62 63 64 65 66 67 68 69

Guyana and Suriname

Orinoco 4 1 1 1 Negro 6 2 1

Branco 4 2

Tocantins and Capim 11 12 11 8 2 2 5 Xingu 7 4 2 1

Tapajós 16 10 10 6 2 6 2 Madeira 2 2 1 3 1 Western Amazon 1 1 1 1 8 9 10 11 12 13 14

Guyana and Suriname 1 22 33

Orinoco 10 7 1 6 Negro 14 24 1

Branco 12 18

Tocantins and Capim 12 44 4 Xingu 8 11 21 8 Tapajós 2 28 23 25 7 Madeira 8 16 11

Western Amazon 4 11 1 2 Brycon falcatus typically possess a conspicuous dark stripe along the basis of anal-fin, the intensity of which, however, varies considerably among populations and even within specimens collected in the same general area. Some specimens from the upper portion of the rio Araguaia in central Brazil (MZUSP 18628, MZUSP 62490, MZUSP 48113, MZUSP 52391) entirely lack the dark stripe. At the other extreme are the specimens from the upper Río Orinoco and upper rio Negro, which possess a very well-developed dark stripe that extends from the origin of the pelvic fin to the caudal peduncle, much as the stripe found in Brycon melanopterus (see above). It is interesting to notice that specimens collected in the rio Arinos at the upper rio Tapajós basin (e.g., MZUSP 56785, MZUSP 60423, MZUSP 61056) possess a well-developed dark stripe, while specimens collected in the same area but kept for some time in fish ponds (MZUSP 61132, MZUSP 61133) lack entirely the dark stripe. This suggests that the expression and the intensity of the dark stripe might vary as a response of some physiological factor.

Finally, a considerable molecular divergence among samples the species from the Río Orinoco in Venezuela, rio Negro in Brazil and upper rio Xingu was detected by Abe et al. (2014). Abe et al. (2014: 12) considered that populations of Brycon falcatus from the Río Orinoco and Río Negro basins were separated by the development of the Vaupes arch. However, Brycon falcatus possess a continuous distribution across the upper rio Negro and upper Río Orinoco afforded by the Río Casiquiare, from where the species is known (see Fig. 99 ), and consequently the genetic divergence between these samples cannot be ascribed to a supposed vicariant event that in fact did not isolated these populations. A much larger sampling is necessary to understand phylogeographical patterns and the possible existence of cryptic species within the populations herein assigned to Brycon falcatus . Until such work is done, it is deemed more parsimonious to consider all these populations as belonging to a single species.

Common names. Brazil: “matrinchã”; “ piabanha ” ( Santos et al., 1984: 41); “voadeira”, “avoadeira”, “matrinchã-pequena”; “jatuarana-miri” (Wallace, in Toledo-Piza, 2002: 116); “miõ wi” (Tukano language, upper rio Negro basin; Lima et al., 2005: 164); “wenawe” (Tuyuka language, upper rio Negro basin; Lima et al., 2005: 164); French Guiana: “moloko blanc”, “maloko”, “mbooko”, “molokoimo” ( Planquette et al., 1996); Suriname: “moroko” ( Richter & Nijssen, 1980: 123; Mol et al., 2007: 115); Guyana: “kurumi” ( Müller & Troschel, 1845: 29); Venezuela: “palambra”, “bócon” ( Taphorn, 1992: 128).

Distribution. Widespread in rivers draining the Brazilian and Guyana shields in the Amazon, Orinoco, and guyanese river systems, and also on scattered localities in western Amazon ( Fig. 99 ). Brycon falcatus is recorded only from clear or dark water rivers and never occur at white/murky-water rivers. Records from the rio Madeira basin are all from shield-draining, clear- to black-water tributaries such as rio Guaporé/Itenez, rio Jamari, rio Aripuanã, and rio Roosevelt. Likewise, records in the western Amazon came from black-water systems as the Lago Amanã near the mouth of rio Japurá in Brazil or the Río Nanay near Iquitos, Peru. From guyanese river systems, we have examined material from the Essequibo, Corantijn, and Maroni/ Marowijne Rivers in Guyana, Suriname and French Guiana, but the species is also reported from the Suriname River (e.g., Richter & Nijssen, 1980; Mol et al., 2007; Mol et al., 2012), Coppename River ( Mol et al., 2006; Mol et al., 2012), Nickerie River (Mol et al., 2012) and Saramacca River (Mol et al., 2012) in Suriname, and Mana River ( Planquette et al., 1996: 226–227) in French Guiana. The present westernmost record for Brycon falcatus is Iquitos and records from more westward localities (e.g., Ecuador; Gilbert & Roberts, 1971; Saul, 1975) need to be re-examined. Recorded as a vagrant species in a river from southern Trinidad ( Phillip et al., 2013: 16; see item “Biogeography”, below).

Ecological notes. As noticed above, Brycon falcatus inhabits exclusively clear- or black-water rivers. Like its congeners, Brycon falcatus is a highly mobile fish and utilizes a great variety of habitats, ranging from river channels, flooded forest, floodplain lakes, to small tributaries. The species undertake massive spawning upstream migrations in the rio Culuene, upper rio Xingu basin, during September/November (pers. obs.), but spawning migrations in the rio Araguaia basin appear to be much more discrete and local (J.B. Nunes, pers. comm.). Specimens associated in small groups of up to 3 individuals were observed while snorkelling in clear-water tributaries of the upper rio Arinos, rio Tapajós basin, Mato Grosso during the late wet season (pers. obs.). Lowe Mc-Connel (1964: 118, 120) noticed downstream migration of the species in the Ireng River (upper Rio Branco basin, Guyana) during the early dry season, and specimens with ripening gonads in the Rupununi River in April (early wet season). At the rio Guaporé (Mato Grosso, Brazil), mature females were collected at the beginning of the rainy season, between October and December ( Rubio et al., 2012). Scale rings indicated a maximum age of five years in specimens from the rio Guaporé ( Rubio et al., 2012). A female with 30 cm SL from the rio Culuene collected early October possessed mature gonads (pers. obs.). Migratory schools in the rio Culuene were observed being attacked by Hydrolycus armatus specimens, and some dying Brycon falcatus were found with deep parallel cuts which very likely were inflicted by this large predatory characin (pers. obs.). An osprey, Pandion haliaetus , was observed with a Brycon falcatus specimen under its talons at the Kuribrong River, Guyana (pers. obs.).

Detailed studies on the diet of Brycon falcatus are Borges (1986), who studied specimens from the middle and lower rio Negro basin in Brazil, and Albrecht et al. (2009), studying specimens from the upper rio Tocantins basin in central Brazil. Borges (1986) found mainly vegetal itens (fruits and seeds) in stomach contents of specimens collected during the rainy season, while during the dry season, arthropods were the main dietary item. Leaves, flowers, and fishes were moderately consumed in both seasons. Fruits commonly found in stomach contents were Ocotea sp. ( Lauraceae ), Tococa sp. ( Melastomataceae ), and Macrolobium acacifolium (Fabaceae) . Albrecht et al. (2009) also found seeds and fruits to be the most important dietary item for the species, followed by ants, coleopterans, fish and terrestrial vertebrates. Correa & Winemiller (2014) reported that the species switched from fruits and seeds to terrestrial invertebrates as its main dietary item from rainy season to dry season in a site at the lower Río Caquetá basin (= Rio Japurá in Brazil) in Colombia, although later than the syntopic B. melanopterus . Matos et al. (2016) recorded invertebrates (mostly insects and Decapoda), fishes, flowers, seeds and fruits as the main itens ingested by Brycon falcatus at the rio Teles Pires basin, and that specimens living in river stretches where an artificial food supply (soybeans and corn) was provided presented a better condition (i.e., more abdominal fat) than specimens living in river stretches where no artificial food supply was provided.

Remarks. Jardine, in Jardine & Schomburgk (1841: 212–213) described Chalceus labrosus from the “river Paduiri” (= Rio Padauari), a locality which lies in the middle rio Negro basin, Amazonas, Brazil, an area visited by Schomburgk in March 1839 ( Schomburgk, 1840). No type material is known for this nominal species. Though poor, the description and plate of Chalceus labrosus clearly correspond to the same species latter described by Müller & Troschel as Brycon falcatus . Jardine, in Jardine & Schomburgk (1841: 212–213) mentions the three series of teeth in the premaxillary (“three rows on the roof of the mouth”), the dark stripe at the basis of anal fin (“a broad black mark running from the centre of its anterior edge for one-third of its length”), and the crescent-shaped blotch at the caudal fin (“a dark bluish black bar running across, parallel to the fork”). The name Chalceus labrosus was never used as a valid species after its original description, while Brycon falcatus has been continuously used in the ichthyological literature during the last 160 years, by well more than 25 authors (see synonymic list, above). We consider thus that Chalceus labrosus fulfills the necessary requisites to be considered as a nomen oblitum (Article 23.9.1 of the International Code of Zoological Nomenclature, 1999), and, as such, as not having precedence over Brycon falcatus , which is herein considered a nomen protectum.

Müller & Troschel (1844: 90) briefly described Brycon falcatus , based on an unspecified number of syntypes collected at Guiana and Suriname by Schomburgk and Dieppering. A little later, the same authors ( Müller & Troschel, 1845: 29, pl. 6, fig. 1) described the species in detail and provided a good illustration of it. Though the type specimens were not examined in the present study, the good description and illustration by Müller & Troschel (1845) leaves no doubt as to the identity of the species. Günther (1864: 335) identified three specimens from BMNH collected by Schomburgk as belonging to the type series, which probably prompted Eschmeyer (1998: 58) in considering this lot (BMNH 1969.12.12:1-3) as being part of the syntypical series of B. falcatus . However, as remarked earlier by Howes (1982: 26), only the specimens deposited at the ZMB were cited in the original description ( Müller & Troschel, 1845: 29) and as such are the only specimens that should be considered as having typical status ( Lima, 2003: 176). In the same papers where Brycon falcatus was described, Müller & Troschel (1844: 91; 1845: 29–30, pl. 6, fig. 2) described Brycon schomburgkii from Guyana. Müller & Troschel (1845) diagnosed the species from Brycon falcatus only by the possession of a longer inner row of dentary teeth, almost reaching the inner symphyseal teeth. However, there is a reasonable degree of intraspecific variation in the extension of the second dentary teeth row in Brycon species, and the variation described by Müller & Troschel (1845) fits within this variation. Eigenmann (1912: 372), who examined the type specimens of both Brycon falcatus and B. schomburgkii , remarked that “the later is undoubtedly the young of the former”, thus considering B. schomburgkii a synonym of B. falcatus , an opinion with which we concur.

Valenciennes (in Cuvier & Valenciennes, 1850: 246–248), when describing Chalceus hilarii , mentioned that part of the syntypical series was collected “dans l’Amazone” by Castelnau. Castelnau (1855: 68) noticed that these specimens were actually collected at Salinas, located at the rio Araguaia basin in Goiás state, Brazil ( Papavero, 1971: 152). Bertin (1948: 14–15) listed three syntypes for Chalceus hilarii , two of which (MNHN 9893, MNHN 9894) were collected by Castelnau at the “Fl[euve]. Amazone”. Géry & Mahnert (1992: 815) selected the specimen MNHN A.8616 as the lectotype of Brycon hilarii (see item “Remarks” of B. hilarii ). Consequently, the specimens MNHN 9893 and MNHN 9894 became paralectotypes of the species. Géry & Mahnert (1992) mentioned that these specimens were collected at Salinas, but incorrectly surmised that this locality was located at the rio Jequitinhonha (a river basin not visited by Castelnau). Due to the poor state of preservation of the paralectotypes, Géry & Mahnert (1992) were unsure whether they were in fact conspecific with the lectotype or not. The examination of one of these paralectotypes (MNHN A.9894) demonstrated, as should be expected by its provenance, that it refers not to Brycon hilarii , but, actually, to B. falcatus .

Günther (1864: 335) described Brycon brevicauda based on three syntypes, BMNH 1864.4.20: 13, from “ Rio Jocintins” (presumably a mispelling of rio Tocantins), and BMNH 1849.4.8: 42; 49, from rio Capim, Brazil. Géry (1964: 450) provided an identification key for what he supposed to be a group of species similar to Brycon falcatus , identifiable by possessing a V-shaped caudal-fin blotch. In that key, Brycon brevicauda was diagnosed from B. falcatus by possessing higher lateral-line and vertical scale counts, lower anal-fin counts, a smaller body depth, by lacking the dark stripe at the anal-fin basis and, possibly, by lacking the inner dentary symphyseal teeth. Howes (1982: 14) also considered Brycon brevicauda as being a valid species, distinct from Brycon falcatus in scale counts, body depth, premaxillary teeth counts, and dentary teeth shape. The examination of large samples from the Guianas, Amazon and Orinoco basins undertook during the present study showed that all these characters are either not valid (i.e., premaxilary teeth counts, lack of symphyseal teeth, dentary teeth shape), or vary considerably within populations (i.e., body depth, anal-fin basis pigmentation), or else present a continuous variation among distinct populations (i.e., scale counts) (see item “Variation”, above). We consider thus Brycon brevicauda as a synonym of B. falcatus .

Steindachner (1882a: 176) briefly described Brycon stuebelii (originally spelled as stübelii ) having as its type locality the Amazon basin (“Amazonestrome”). Soon thereafter Steindachner (1882b: 13–14) redescribed the species in detail, and specified its type-locality as being “ Rio Amazonas (Iquitos)”. Steindachner (1882b: 13) compared Brycon stuebelii with a single congener, B. melanopterus , from which he diagnoses it by possessing a shorter dark stripe at the anal-fin basis and a supposedly larger second infraorbital bone. Géry (1964: 450) considered Brycon stuebelii as provisionally valid and considered it as belonging to a group of species similar to B. falcatus , being supposedly distinct from the latter by possessing higher scales counts. Howes (1982: 45), however, considered Brycon stuebelli as a possible synonym of B. falcatus . The holotype of Brycon stuebelii was not examined during the course of the present study, but Steindachner’s description and illustration show a typical Brycon falcatus specimen, with a well-defined crescent-shaped blotch on the caudal-fin, a color pattern no longer displayed by the now faded holotype ( Zarske, 2003: 16, fig. 7). Curiously, all subsequent specimens of Brycon falcatus collected in the western portions of the Amazon basin, including specimens collected at Iquitos, does not possess a V- or crescent-shaped blotch on caudal fin, but instead, the dark pigmentation is considerably more developed or even entirely confined to the upper caudal-fin lobe (see item “Variation”, above).

Brycon bicolor was described by Pellegrin (1909a: 12–13) based on three specimens collected at at the Rio Orinoco, without a precise locality. The collector of the type material, Jean Chaffanjon, was a French explorer who traveled between 1885–1890 in the Río Orinoco, and explored its upper reaches, including the Río Caura and upstream into the Río Orinoco to the rapids of the Raudal de los Guaharibos ( Huber, 1995). The species was compared by Pellegrin (1909a) with Brycon falcatus and considered to be distinct due to the possession of smaller scales. Howes (1982: 11, 13–14) examined the syntypes and considered it a “very characteristic taxon hardly to be confused with any other Brycon species”. The distinctiness of Brycon bicolor , according to Howes (1982), relied in its color pattern, which consisted in a dark stripe extending across the base of anal fin and a blotch extending diagonally from caudal peduncle to the upper lobe of caudal fin. Géry & Mahnert (1992: 802) also examined the syntypes and considered Brycon bicolor to be more related to B. melanopterus and B. cephalus (= B. amazonicus ) than to B. falcatus due to the presumably distinct V-shaped caudal-fin pigmentation present in the latter species. Lima (2003: 175), listing the valid species of Bryconinae , considered the species provisionally valid, but mentioned the possibility that the species might be a synonym of Brycon melanopterus . This supposition was based on the fact that the syntypes exhibit a color pattern similar to the one found in this latter species. However, after we have examined the syntypes of Brycon bicolor (MNHN 87746-748), and studied in more detail Brycon specimens from the upper Río Orinoco and upper rio Negro basins, it became obvious that these specimens does not belong to B. melanopterus (see item “Comparisons” of B. melanopterus , and item “Variation”, above), but instead are best interpreted as representing one extreme of variation in pigmentary features found within a polymorphic B. falcatus . Accordingly, Brycon bicolor is herein considered a synonym of B. falcatus . Thus, records in the literature for Brycon melanopterus in the upper rio Negro and upper Río Orinoco basins ( Myers & Weitzman, 1960; Lima et al., 2005) actually represent misidentifications of this unusually-pigmented color morph of B. falcatus .

Fowler (1941: 192–194) described Brycon matrinchao for the rio Parnaíba, Piauí, northeastern Brazil. Fowler (1941: 194) did not compared Brycon matrinchao with any other Brycon species, with the exception of Brycon hilarii , and as a matter of fact did not put forward any reasoning justifying the description of the species. Géry (1964: 450) considered Brycon matrinchao as belonging to a putative group of species related to B. falcatus , from which it would be diagnosed by possessing higher scales counts. The holotype of Brycon matrinchao (ANSP 69619) was examined during the course of the present study, and it is undoubtedly a specimen of B. falcatus belonging to the populations that display relatively high scale counts (see item “Variation”, above). Despite a considerable sampling effort in the last twenty years (e.g., Ramos et al., 2014), no additional specimens of Brycon falcatus were collected in the rio Parnaíba basin. In fact, the only other putative record of a Brycon species occurring in the rio Parnaíba is a lot of Brycon orthotaenia collected by the Thayer Expedition, which also constitutes a doubtful record (see item “Distribution” of the latter species, and the item “Biogeography”, below). Several species recorded by Fowler (1941) from the rio Parnaíba and another drainages from northeastern Brazil were never collected again in that area and clearly are mislabelled specimens which were rather probably collected in the rio Tocantins system (Roberts, 1973: 213; Vari, 1995: 80; Vari & Harold, 2001: 45–46; Castro & Vari, 2004: 151). It is very unlikely that fish species highly prized and exploited by fishermen such as a Semaprochilodus (Castro & Vari, 2004: 151) or a Brycon species would have escaped further notice, if in fact they were truly present in the rio Parnaíba basin. We consider thus that the reported occurrence of Brycon falcatus in the rio Parnaíba basin to be based on a mislabelled specimen, and that the holotype of B. matrinchao was actually collected somewhere in the Amazon basin, perharps in the rio Tocantins basin.

Géry & Mahnert (1992: 800–802) identified as a possible new species specimens of Brycon belonging to the INPA collection from the rio Aripuanã and Lago Amanã. These specimens were considered by Géry & Mahnert (1992) to be distinct from Brycon brevicauda , and similar to B. bicolor , by possessing the dark pigmentation confined to the upper caudal-fin lobe. We have examined one of the lots studied by Géry & Mahnert (1992) (INPA 16412, from the rio Aripuanã) and specimens from the Lago Amanã and nearby areas (MZUSP 99213, MCP 29776, MCP 29774, MCP 29771, MCP 29775). As noticed under the item “Variation”, above, the intensity of pigmentation in the lower caudal-fin lobe vary in intensity across the populations of Brycon falcatus , with a distinct east-west clinal tendence of decrease of intensity of pigmentation in the lower caudal-fin lobe. The population of Brycon falcatus from the rio Madeira basin is variable in this respect, and specimens ranging from a lower caudalfin lobe much less pigmented than the upper caudal-fin lobe to specimens presenting a almost symmetric, V-shaped caudal-fin blotches are present in the area, while specimens from the lago Amanã area typically possess a lower caudal-fin lobe much less pigmented than the upper caudal-fin lobe, a condition which is in fact a rule for B. falcatus populations from the western Amazon (see item “Variation”, above). In sum, the purported specific distinctness of the populations from the rio Aripuanã and Lago Amanã hypothesized by Géry & Mahnert (1992) constitute actually only in the extreme of a continuous variation of the lower-caudal fin pigmentation within Brycon falcatus populations.

Material examined. Type material. MNHN A.9894 (1, 169.5 mm SL): " L'Amazone " (= Brazil, Goiás, Salinas, c. 13°40’S, 50°14’W, rio Araguaia basin); F. de Castelnau, 1844 . Paralectotype of Chalceus hilarii Valenciennes (designated by Géry & Mahnert, 1992: 815). BMNH 1849.4.8: 42, 49 (2, 87.4–92.7 mm SL): “ Rio Capin” (= Brazil, Pará, Rio Capim); “purch. Stevens ” (i.e., collected by H.W. Bates) ; syntypes of Brycon brevicauda Günther, 1864 . BMNH 1842.4 .20.13 (1, 232.0 mm SL): “ Rio Jocintins ” (= Rio Tocantins, Brazil); “pres. by M. Gardiner ” ; syntype of Brycon brevicauda Günther. MNHN 87746-748 (3, 110.0– 120.9 mm SL): “Orénoque”, Chaffanjon. Syntypes of Brycon bicolor Pellegrin. ANSP 69619 (1, 149.2 mm SL): Brazil: “ Rio Parnahyba; Therezina; Piauhy ”; R. von Ihering, 1936 . Holotype of Brycon matrinchao Fowler.

Non types. French Guyana. MNHN 2000-4476 (1, 162.6 mm SL): Maroni River at Maripasoula , 3°38’48’’N, 54°2’27’’W; IRD-Cayenne, 15 June 1999 . MNHN 1999-1451 (1, 102.0 mm SL): Maroni River, Saut Singatelet , c. 4°20’N, 54°23’W; P. Planquette, 15 Oct 1979 . MNHN 2004-0345 (1, 99.1 mm SL); MNHN 2004-0243 (1, 70.9 mm SL): Saint Laurent du Maroni , 5°28’N, 54°3’W ; O. Tostain, 2003. MNHN 1998-1822 (1, 257.9 mm SL): Saint Laurent du Maroni , 5°28’N, 54°3’W; P.- Y. Le Bail, no date . Suriname, Nickerie District: MZUSP 38255 (4, 1 cs, 116.9–131.6 mm SL): woodland stream about 0.5 km inland of Camp Mataway, Corantijn River basin, 4°48'N, 57°43'W; R.P. Vari, 21 Sept 1980 . USNM 225975 (2, 129.1–152.0 mm SL): small creek entering Corantijn River, on east side approx. 300 m north of Amotopo boat landing, 3°33’N, 57°40’W; R.P. Vari et al., 19 Sept 1980 . USNM 225625 (3, 134.7– 141.2 mm SL): creek opposite logging camp, 2 and a half hours S of Matapi, approx. 2 km downstream Cow Falls , 4°59’N, 57°38’W; R.P. Vari et al., 11 Sept 1980 . USNM 226161 (66, 77.1–108.1 mm SL): Corantijn River at km 180, side channel along Surinamese shore, 5°8’N, 57°18’W; R.P. Vari et al., Sept 1980 . USNM 225624 (4, 127.6– 136.6 mm SL): Mataway Creek approximately 8 km from its intersection with Corantjin River, 4°47'N, 57°45'W; R.P. Vari et al., 11 Sept 1980 . USNM 226122 (9, 96.7–140.0 mm SL): Matapi Creek ca. 1 km from intersection with Corantijn River, 5°00'N, 57°16'W; R.P. Vari et al., 9 Sept 1980 . AMNH 54849 (98.9– 118.8 mm SL): stream near Camp Avanavaro, about 3 mi. downstream of Devis Falls (Kabalebo River drainage); R.P. Vari et al., 7 Dec 1979 . AMNH 54976 (5, 103.4– 114.2 mm SL): small stream just south of Tiger Falls on Corantijn River approx. km 405, c. 4°0’N, 58°2’W; R.P. Vari et al., 11 Dec. 1979 . AMNH 54876 (7, 100.2– 124.3 mm SL): Toeboeroe creek , trib. Corantjin River at km 220; R.P. Vari et al., 8 Dec 1979 . AMNH 54764 (9, 97.4– 113.7 mm SL): Corantijn drainage, Kapoeri Creek about 7 km from intersection with Corantjin River; R.P. Vari et al., 5 Dec 1979 . AMNH 54904 (10, 90.0– 105.9 mm SL): small inlets on sand bar opposite entrance of Matawai creek in Corantjin River; R.P. Vari et al., 8 Dec 1979. Guyana , Essequibo River basin. MCZ 30162 (1, 193.3 mm SL) ; FMNH 53352 (2, 196.5–222.0 mm SL): Tukeit , Potaro River, c. 5°16’N, 59°23’W ; C.H. Eigenmann, 1908. FMNH 7472 (1, 188.8 mm SL): same locality; S.E. Shideler, 1908 . AMNH 73000 (6, 82.5–124.9 mm SL): Mazaruni-Potaro District, Cuyuni River, just upstream of Caowry Creek , c. 6°23’N, 58°43’W; R.E. Schmidt, K. Schmidt & R. Pappantoniou, 18 Aug 1983 . UMMZ 216328 (2, 102.1–107.0 mm SL): Essequibo River, Bartica , 6°24’N, 58°37’W ; Carslon & Persand, 12 Sept 1971. UMMZ 216215 (3, 41.4–50.6 mm SL): small creek trib. Essequibo River, south of Bartica ; F. Cichocki, 21 May 1972 . UMMZ 216492 (2, 51.2–66.0 mm SL): Essequibo River, opposite Bartica; F. Cichocki & Douglas, 4 June 1972 . UMMZ 216401 (1, 38.3 mm SL): Essequibo River, east bank up to Makouria Quarry; F. Cichocki et al., 18 May 1972 . BMNH 1972.19.17: 1398-1411 (14, 82.7–125.6 mm SL): Essequibo River, Moraballi , c. 6°12’N, 58°34’W; R. Liley, 3 Nov 1959 . FMNH 53350 (1, 89.7 mm SL): Essequibo River, Rockstone , 6°1’N, 58°34’W ; C.H. Eigenmann, 1908. ANSP 177356 (2, 185.0–255.0 mm SL): Siparuni River, Levi Falls Creek ; G. Watkins et al., 5 Dec 1997 . ANSP 175740 (1, 250.0 mm SL): Essequibo River, approx. 3 hours above Kupurukari field station; W.G. Saul et al., 30 Jan 1997 . ANSP 178559 (1, 248.0 mm SL): Burro Burro River: ca.35 minutes upstream from Burro Burro campsite ( Water Dog Rapids ), 4°10'48''N, 58°50'46''W; G.G. Watkins et al., 22 Jan 1997 . ANSP 175455 (1, 106.0 mm SL): Siparuni VIII-2, blackwater creek tributary of Burro Burro River, upstream from Burro Burro campsite, 4°42'47''N, 58°51'46''W ; G.G. Watkins et al., 21 Jan 1997. ANSP 175451 (1, 141.4 mm SL): Siparuni VIII-2, clear water creek at campsite 3.1 miles from Kurupukari, field station on Kurupukari-Surema River Road ( Tiger cr.), 4°38'00''N, 58°42'59''W; W.G. Saul et al., 5 Febr 1997 . ANSP 176666 (1, 252.0 mm SL); ANSP 176667 (1, 165.3 mm SL): Burro Burro River, Water Dog Falls , 4°10'48''N, 58°50'46''W; E. McBirney et al., 17–20 Nov 1997 . ANSP 176668 (1, 137.4 mm SL): Burro Burro River, Lunch Rock , 4°41'28''N, 58°51'8''W; C. Watson et al., 20 Nov 1997 . ANSP 176667 (1, 165.3 mm SL): same locality; G. Watkins et al., 17 Nov 1997 . ANSP 175456 (1, 134.4 mm SL): Siparuni VIII-2, Paddle Rock lake , ca. 15 min downstream from Essequibo campsite , Essequibo River, 4°43'57''N, 58°42'53''W; W.G. Saul, 27 Jan 1997 . ANSP 176669 (1, 135.2 mm SL): Essequibo River, black water creek 2 km downstream from Paddle Rock campsite, 4°45'40''N, 58°43'05''W; C. Watson et al., 24 Nov 1997 . ANSP 175454 (1, 100.7 mm SL): Siparuni VIII- 2, Essequibo River, 180 yd. upstream from Essequibo campsite ( Maipuri ), 4°45'43''N, 58°45'52''W ; D. Allicock, 27 Jan 1997. ANSP 176670 (2, 128.4– 134.3 mm SL): Siparuni River, small side stream of Siparuni next to Tumble Down Falls, 4°48'39''N, 58°51'11''W ; G. Watkins et al., 8 Dec 1997. ANSP 175457 (1, 121.3 mm SL): Siparuni VIII-2, Essequibo River: sandbars in vicinity of Maipuri campsite, 4°34'17''N, 58°35'17''W ; W.G. Saul et al., 2 Feb. 1997. ROM 64251 (2, 93.1–101.9 mm SL): Region 6 (Kurupukari), about 1.6 km downstream from Tambikabo inlet, 4°48’40’’N, 58°49’20’’W ; E. Holm et al., 13 Oct 1990. ANSP 39752 (3, 86.3–109.1 mm SL): Rupununi River (no precise locality); J. Ogilvie, 1911 . BMNH 1972.7.27:52-76 (25, 79.5–255.0 mm SL): Rupununi District (no precise locality); R.H. Lowe McConnel, no date . MNHN A. 8614 (1, 244.3 mm SL, half skin) ; MNHN A.9831 (1, 112.4 mm SL) ; MNHN 4388 (2, 110.0– 115.8 mm SL); MNHN 101 (2, 205.3– 218.3 mm SL): “Fl. Essequibo , Guyane Anglaise”; R. Schomburgk, no date . Venezuela, Río Orinoco basin, Depto . Amazonas: AMNH 93064 (1, 197.7 mm SL): Rio Mavaca, upriver from base camp, at tributary, c. 2°31’N, 65°10’W; C.J. Ferraris , A. Machado-Allison et al., 18–20 March 1989 . AMNH 93065 (1, 202.8 mm SL): Río Mavaca, at base camp, c. 2°31’N, 65°10’W; C.J. Ferraris & J. Daly, 17 March 1989 . ANSP 159731 (1, 114.0 mm SL): Río Sipapo, above Pendare , 4°51’N, 67°44’W; B. Chernoff et al., 12 Nov 1985 . ANSP 159734 (1, 91.5 mm SL): Caño entering Río Sipapo at raudal del Caldero , c. 3 km above confluence with Río Orinoco, 5°4’N, 67°46’W; B. Chernoff et al., 14 Nov 1985 . ANSP 159732 (1, 110.1 mm SL): morichal 26.9 km from Puerto Ayacucho, along Puerto Ayacucho- Caicara highway; B. Chernoff et al., 15 Nov 1985 . ANSP 159733 (1, 127.2 mm SL): Río Cataniapo at bridge on Puerto Ayacucho-Samariapo carretera, 3 km S of Puerto Ayacucho, 5°32'N 67°31'W; B. Chernoff et al., 11 Nov 1985 . FMNH 85689 (4, 2 cs, 92.4–147.7 mm SL): 50 km towards Puerto Ayacucho from Puerto Novo; J. Thomerson et al., 14 Jan 1975 . USNM 270181 (3, 97.3–120.0 mm SL): Laguna Provincial, approx. 20 km north of Puerto Ayacucho, 5°50’N, 67°30’W ; R.P. Vari et al., 1 Dec 1984. INHS 61580 (1, 118.3 mm SL): Caño Agua Linda (trib. Río Orinoco), 5°50'24''N 67°27'10''W ; L.M. Page et al., 22 Jan 1992. ANSP 159730 (2, 83.9–97.7 mm SL): Caño crossing Puerto Ayacucho-El Burro hwy., c. 7 km from intersection of Puerto Ayacucho-Caicara hwy., 5°56’N, 67°21’W ; B. Chernoff et al., 14 Nov 1985. ANSP 159721 (1, 109.3 mm SL): Río Orinoco at El Burro , 6°12’N, 67°26’W; B. Chernoff et al., 26 Nov 1985 . BMNH uncat. (1, 86.5 mm SL): Río Orinoco, Puerto Ayacucho, 5°40’N, 67°38’W; Delmastro, July 1980 . UMMZ 240018 (3, 94.8–136.0 mm SL): mouth of Río Guaviare, opposite San Fernando de Atabapo, 4°2’N, 67°43’W; J.S. Albert et al., 2 Jan 1994 . UMMZ 239924 (1, 93.7 mm SL): Río Orinoco, 5 km upstream from San Fernando de Atabapo, c. 4°2’N, 67°40’W; J.S. Albert et al., 27 Dec 1993 . ANSP 161212 (8, 106.4– 149.8 mm SL): Río Ventuari ca. 12 km from its confluence with Río Orinoco, 4°4’N, 66°56’W; B. Chernoff et al., 25 March 1987 . FMNH 104026 (1, 100.4 mm SL); FMNH 104027 (1, 92.6 mm SL); FMNH 104028 (1, 117.5 mm SL): Río Ventuari, c. 12 km above mouth in Río Orinoco , Laguna Pavón, 4°4’N, 66°56’W; B. Chernoff et al., 24 Jan 1991 . FMNH 161210 (1, 157.1 mm SL): Río Iguapo (trib. Río Orinoco), c. 1 hr. above its mouth, 3°7’N, 65°28’W; H. Lopez et al., 13 March 1987 . CAS-SU 52 635 (1, 102.8 mm SL): Rio Orinoco, Orinoco bifurcation, Tamatama beach, c. 3°9’N, 65°51’W; C. Ternetz, 14 March 1925 . CAS-SU 64370 (1, 230 mm SL): Rio Orinoco bifurcation, Cano Tamatama into Rio Orinoco, c. 3°9’N, 65°51’W; C. Ternetz, 17 March 1925 . Estado Bolívar: ANSP 159736 (1, 100.7 mm SL) : Río Caura at Puerto Las Majadas , 7°38’N, 64°50’W; L. Aguana, 23 Nov 1985 . MZUSP 96418 (1, 54.2 mm SL): Caicara del Orinoco, Río Orinoco, Puerto Cedeño , 7°39’6’’N, 66°10’34’’W; M.C.C. de Pinna & P. Hernadez, 20 July 2004 . LBP 2187 (2, 98.4–147.6 mm SL): Caicara del Orinoco , Laguna de Castilleros, 7°30’51’’W, 66°9’20’’W ; A . Granado, 17 Jul 2004. LBP 3027 (4, 101.2–172.0 mm SL): Caicara del Orinoco , Río Orinoco, 7°38’11’’N, 66°19’4’’W ; C. Oliveira & A . Granado, 2 Oct 2005. CAS-SU 68916 (1, 107.8 mm SL) ; CAS-SU 54649 (1, 101.4 mm SL); CAS-SU 56 784 (1, 103.3 mm SL); CAS-SU 54566 (1, 104.5 mm SL): Caño de Quiribana, near Caicara , c. 7°36’N, 66°11’W; C. Ternetz, April– May 1925 . UF 80419 (1, 112.1 mm SL); UF 80474 (1, 125.3 mm SL): bridge on Río Chaviripa on Caicara-San Fernando de Atabapo (Puerto Ayacucho) road, c. 7°0’N, 66°31’W; D.C. Taphorn et al., 16 Apr 1984 . ANSP 159729 (1, 102.9 mm SL): river and flooded area 15 km N of Maniapure on Caicara-Puerto Ayacucho hwy. (Río Chaviripa?), c. 7°0’N, 66°31’W; B. Chernoff et al., 16 Nov 1985 . MZUSP 96499 (1, 69.2 mm SL): Cedeño, Río Parguaza, Puente Parhueña village , 5°53’30’’N, 67°24’14’’W; M.C.C. de Pinna & C. Oliveira, 19 Jul 2004 . Estado Apure: MZUSP 62447 (2, 104.6– 124.4 mm SL) : Apure, laguna near Caño La Pica; F. Provenzano et al., 14 May 1989. INHS 61479 (3, 84.6–113.5 mm SL) : Apure , Caño San Miguel (trib. Río Cínaruco), 6°34’24’’N 67°17’32’’W; L.M. Page et al., 20 Jan 1992 . INHS 61402 (1, 115.1 mm SL): Laguna Larga (Río Cínaruco), 6°33’19’’N 67°24’49’’W; L.M. Page et al., 19 Jan 1992 . FMNH 69901 (1, 89.3 mm SL); FMNH 69902 (8, 94.1– 169.4 mm SL): Río Cinaruco, c. 6°33’N, 67°18’W; W.P. Braker & Zunwalt, Feb 1967. Venezuela, Depto . Amazonas , Rio Negro basin: ANSP 161211 (1, 102.4 mm SL) : Río Pamoni, lagoon ca. 0.5 km from confluence of Río Casiquiare, 2°50’N, 65°53’W; B. Chernoff et al., 18 March 1987 . ANSP 162802 (1, 272.0 mm SL): mouth of Río Pamoni at Río Casiquiare, 2°49’N, 65°55’W; W.G. Saul et al., 18 March 1987 . CAS-SU 56148 (1, 109.5 mm SL); CAS-SU 54738 (1, 127.7 mm SL); CAS-SU 54652 (2, not measured); CAS-SU 54652 (2, 107.9– 117.2 mm SL): Rio Casiquiare, Laje Curare (not located); C. Ternetz, 2 March 1925 . CAS-SU 54653 (2, 113– 124.6 mm SL): Rio Casiquiare, Punta de la Isla Guachancho; C. Ternetz, 26 Febr 1925 . USNM 270180 (1, 105.4 mm SL): San Carlos de Río Negro , Río Negro above town landing, 1°55’N, 67°3’W ; A. Machado et al., 3 Dec 1984 . USNM 270182 (5, 80.8–99.8 mm SL): Río Negro about 0.5 hour above San Carlos de Río Negro , 1°58’N, 67°4’W ; R.P. Vari et al., 4 Dec 1984. CAS-SU 54651 (1, 109.8 mm SL); CAS-SU 69885 (1, 106.0 mm SL): Rio Negro, sandy point n. of “ Amanadona ” (= Santa Rosa de Amanadona , 1°28’30’’N, 66°54’30’’W); C. Ternetz, 21 Febr 1925 . Colombia, Río Orinoco basin: NRM 26206 (1, 70.5 mm SL): Prov . Guainía , Río Guaviare drainage, Caño Carbón, Cuayare, 3°56'N 67°50'W; T. Hongslo, 28 June1976. Brazil, rio Capim basin: MZUSP 17894 (1, 115.1 mm SL) : Pará, São Domingos do Capim, igarapé Pirajauara, trib. rio Capim , c. 1°44’S, 47°47’W; EPA, 12 Aug 1970 . MZUSP 17957 (5, 79.2–92.4 mm SL): Pará, Badajós, lago Maria Preta, rio Capim , c. 2°30’S, 47°40’W; EPA, 18 Aug 1970 . Rio Tocantins basin . Pará: MZUSP 18051 (9, 143.8– 160.1 mm SL): Paraná Samuuma, mouth of rio Tocantins, c. 1°56’S, 49°12’W; EPA, 4 Sept 1970 . MZUSP 18068 (15, 100.4– 127.6 mm SL): Mocajuba, igarapé Oxipucu , 2°34’S, 49°31’W; EPA, 8 Sept 1970 . MZUSP 18087 (30, 1 cs, 98.1–113.9 mm SL): rio Tocantins, between Mocajuba and Baião, c. 2°39’S, 49°37’W; EPA, 9 Sept 1970 . INPA 16424 (1, 191.9 mm SL); INPA 16368 (1, 119.7 mm SL); INPA 16386 (1, 168.0 mm SL); INPA 16382 (1, 146.4 mm SL): rio Tocantins, Acarí Pucu , 2°42’S, 49°43’W ; Eq. Ictiologia/INPA, 1981–1982. MZUSP 18089 (5, 106.4–112.0 mm SL): Baião , rio Tocantins, 2°48’S, 49°41’W; EPA, 9–10 Sept 1970 . MZUSP 18077 (21, 103.4– 135.3 mm SL): Baião, igarapé do Limão, rio Tocantins; EPA, 9 Sept 1970 . MZUSP 18195 (3, 100.3–105.0 mm SL): igarapé dos Cinco, km 5 on road Tucuruí-Mato Grosso; EPA, 22 Sept 1970 . MZUSP 18200 (1,111.5 mm SL): igarapé Urubu, near posto Trocará, rio Tocantins; EPA, 24 Sept 1970 . INPA 16392 (2, 206.7– 210.9 mm SL); INPA 16373 (2, 141.4– 146.7 mm SL): Icangui , rio Tocantins, 3°27’S, 49°36’W ; Eq. Ictiologia/INPA, 1980–1985. MZUSP 18115 (4, 112.9– 196.6 mm SL): marginal lagoons of rio Tocantins, near Tucuruí; EPA, 14 Sept 1970 . MZUSP 61991 (1, 109.9 mm SL): Tucuruí, rio Tocantins, downstream Tucuruí dam, 3°42'S 49°40'W ; F.C.T. Lima, 17 May 2000 . INPA 16448 (1, 192.6 mm SL): rio Tocantins, Tucuruí fish market; Eq. Ictiologia / INPA, 13 March 1982 .. INPA 16452 (5, 43.3– 73.5 mm SL): rio Tocantins, Tucuruí reservoir, c. 4°2’S, 49°40’W; Martinho, 13 March 1986 . INPA 16431 (3, 185.6– 199.1 mm SL): rio Tocantins, Breu Branco , c. 4°11’S, 49°37’W ; Eq. Ictiologia/INPA, 13 May 1981. INPA 16387 (1, 95.3 mm SL): rio Tocantins, igarapé Pucuruizinho; Eq. Ictiologia / INPA, 9 July 1982 . MZUSP 18145 (1, 84.3 mm SL); MZUSP 18134 (3, 89.3–98.9 mm SL): pool facing Jatobal , rio Tocantins, 4°32’S, 49°32’W; EPA, 17–18 Sept 1970 . MZUSP 18163 (10, 88.9–111.1 mm SL): lagoon near canal do Capitariquara, near Jatobal, rio Tocantins; EPA, 18 Sept 1970 . INPA 16362 (1, 109.0 mm SL);: Itupiranga , rio Tocantins, 5°8’S, 49°19’W ; Eq. Ictiologia/INPA, 1980–1981. INPA 16381 (1, 84.6 mm SL): Itupiranga, rio Tocantins, Lago Gracílio; Eq. Ictiologia / INPA, 1 July 1982 . MZUSP 26924 (1, 96.8 mm SL): Marabá , rio Tocantins, 5°9’S, 49°6’W; N.J.H. Smith, April 1979 . MZUSP 19260 (1, 193.8 mm SL): São João do Araguaia, at the confluence of rio Araguaia and rio Tocantins, 5°22’S, 48°43’W; SUDEPE, 1977–1978 . MZUSP 31503 (1, 218.9 mm SL): Parauapebas, rio Itacaiúnas , igarapé Boa Vista; M. Goulding, Nov 1983 . MZUSP 56946 (2, 199.2– 211.6 mm SL); MZUSP 56943 (3, 194.3– 212.9 mm SL): Parauapebas, rio Itacaiúnas, Caldeirão , Serra dos Carajás, c. 5°40’S, 50°16’W; M. Goulding, April–July 1983 . MZUSP 59100 (5, 157.5– 164.1 mm SL): Parauapebas, Serra dos Carajás, rio Itacaiúnas, Cachoeira Carreira Comprida ; M. Goulding, 14 Oct 1983. Mato Grosso: LBP 4005 (4, 113.3–125.0 mm SL): São Félix do Araguaia , Lago Morto , 11°40’0’’S, 50°51’00’’W ; R. Devidé & C. Martins, 24 Oct 2006. MZUSP 17023 (1, 111.8 mm SL); MZUSP 17024 (1, 113.7 mm SL): Santa Teresinha, rio Araguaia , 10°28’S, 50°30’W; H. A. Britski, Oct 1964 . MZUSP 54444 (2, 127.1– 172.2 mm SL): rio Cristalino , c. 12°43’S, 50°42’W; R. A. Silvano, 3 Oct 1997 . MZUSP 16448 (24, 121.1– 209.1 mm SL): rio São Domingos, trib. rio das Mortes, São Domingos village , 13°33’S, 51°25’W; Exp. Inst. Butantã / Depto. de Zoologia, Sept–Oct 1949 . MZUSP 3845 (15, 130.1– 215.7 mm SL): same locality; A. Hoge, 1950 . MZUSP 52332 (1, 190.9 mm SL): Cocalinho, rio Araguaia , 14°24’S, 50°59’W; R.S. A. Matias, July 1997 . LBP 12816 (1, 97.9 mm SL): Cocalinho, rio Araguaia , 13°18’37’’S, 50°36’48’’W; R. Devidé et al., 29 Sept 2009 . MZUSP 62537 (3, 172.0– 197.7 mm SL): Cocalinho, rio Araguaia, near ilha do Biratã , c. 14°30’S, 50°59’W; W. Severi et al., 25–26 July 1997 . MZUSP 18628 (2, 184.6– 214.7 mm SL): Cocalinho, Lago Dumbá, rio Araguaia , c. 14°30’S, 50°59’W; EMGOPA, 1976 . Maranhão: CAS 68839 (1, 123.2 mm SL): rio Tocantins below Imperatriz , 5°30’S, 47°31’W ; C. Ternetz, 16 Apr 1924. Tocantins: INPA 20064 (1, 126.3 mm SL): Caseara, rio Araguaia , lago das Ariranhas, P.E. Cantão, 9o43’47” S, 50o 9’14” W ; Eq. Ictiologia INPA, 20 May 2000. UNT 448 (1, 155.4 mm SL): Dueré, rio Formoso , c. 11°23’S, 49°41’W ; NEAMB, 23 Aug 1997. UNT 1971 (1, 107.3 mm SL): Tocantinópolis, ribeirão Matrinchã , c. 6°19’S, 47°26’W ; NEAMB, 26 June 2000. CAS 68824 (1, 214 mm SL); CAS 68825 (4, 181.5– 192.3 mm SL): Ribeirão Presídio, trib. Rio Tocantins, below Porto Nacional; C. Ternetz, 13 Feb 1924 . UNT 3457 (1, 129.7 mm SL): rio Tocantins , Porto Nacional, 10°42’S, 48°25’W; NEAMB, 21 Feb 2002 . UNT 3225 (1, 96.6 mm SL): Brejinho de Nazaré, riacho Sussuarana , c. 11°3’S, 48°35’W ; NEAMB, 15 Feb 2002. UNT 2013 (1, 131.3 mm SL): Peixe, rio Santa Tereza (trib. rio Tocantins), 11°47’S, 48°38’W ; NEAMB, 12 April 2000. UNT 451 (1, 193.8 mm SL); UNT 452 (1, 221.4 mm SL): Paranã, rio Paranã, 12°37’S, 47°53’W ; NEAMB, 24–26 March 1998. UNT 1970 (1, 106.4 mm SL): Paranã, rio Maranhão ; NEAMB, 21 Apr 1998. Goiás: MCP 17213 (1, 1, 190.2 mm SL): Luís Alves, rio Araguaia , marginal lagoons, 13°14'S, 50°35'W ; F.L.T. Garro, 21 April 1994. MZUSP 89614 (1, 111.7 mm SL): Luís Alves, rio Verde (trib. rio Araguaia ), 13°9’28’’S, 50°30’22’’W ; A. Akama, 10 Apr 2004. MZUSP 52391 (1, 200.9 mm SL): rio Araguaia, Bandeirantes , 13°41’S, 50°48’W; R.S . A. Matias, July 1997. MZUSP 48113 (4, 197.7– 224.6 mm SL): Aragarças, rio Araguaia , c. 15°54’S, 52°15’W ; W.P. Margarido, 6 July 1994. MZUSP 70418 (1, 179.5 mm SL): Serra da Mesa dam, rio Palmeirinha , 14°03'57'’S, 48°29'37'’W; D.F. Moraes & D . A. Halboth, 8 June 1997 . MZUSP 70415 (1, 243.7 mm SL): rio Maranhão, old bridge between Uruaçu and Niquelândia, 14°31'27'’S, 49°2'33'’W; D.F. Moraes et al., 7 April 1998 . MZUSP 70416 (1, 85.4 mm SL): rio Maranhão, between the mouth of rio Bagagem and rio Tocantizinho , 13°56'S, 48°17'W; D.F. Moraes & D . A. Halboth, 6 Dec 1996 . MZUSP 70417 (2, 109.9– 245.6 mm SL): Serra da Mesa dam, córrego Boa Nova, 13°47'00'’S, 48°25'01'’W; D.F. Moraes, 6 Feb 1997. Rio Xingu basin . Pará: MZUSP 29922 (3, 59.2–97.9 mm SL) ; MZUSP 56945 (151, 117.2– 193.5 mm SL); MZUSP 31448 (1, 153.5 mm SL); MZUSP 56811 (1, 155.7 mm SL); MZUSP 56947 (1, 194.3 mm SL); MZUSP 30755 (2, 82.6–93.8 mm SL); MZUSP 58985 (3, 97.1–100.9 mm SL): Belo Monte, rio Xingu , 3°7'S 51°42'W; M. Goulding, July–Aug 1983 . MZUSP 29923 (3, 89.5–129.8 mm SL); MZUSP 58986 (4, 93.6–107.8 mm SL): Belo Monte, rio Xingu (rocky pool), 3°7'S 51°42'W; M. Goulding, 26 Sept 1983 . MZUSP 29928 (1, 103.4 mm SL): igarapé do Santo Antônio, near Belo Monte, rio Xingu ; M. Goulding, 27 Sept 1983 . INPA 15747 (4, 121.5– 130.4 mm SL); INPA 4225 (1, 86.4 mm SL); INPA 15745 (1, 166.5 mm SL): rio Xingu, Altamirim, ilha do Sr. Izaltino , 3°16’21’’S, 52°12’7’’W; J. Zuanon, Oct 1996 – Aug 1997. INPA 15748 (1, 149.2 mm SL): rio Xingu, Souzel, ilha da Bela Vista , 3°24’22’S, 51°43’3’’W ; J. Zuanon et al., 27–28 Sept 1996. ZUEC 4487 (1, 98.9 mm SL): Altamira, rio Xingu , Buraco do Inferno; J. Zuanon, 7 Sept 1997 . INPA 4226 (4, 89.6–95.9 mm SL): rio Xingu , Ilha de Babaguara; L. Rapp Py-Daniel & J. Zuanon, 5 Oct 1990. MZUSP 105722 (1, 170.7 mm SL): Altamira, rio Xingu, Caitucá , 3°33’48’’S, 51°51’49’’W ; Eq. Ictiologia UFPA, 14 Sept 2001. MNHN 1998-1197 (3, 97.1–181.1 mm SL): Altamira, rio Xingu, Caitucá , 3°33’48’’S, 51°51’49’’W; M. Jégu, Oct 1992 . MZUSP 106211 (1, 159.0 mm SL): Altamira, rio Xingu, Paquiçamba , 3°33’44’S, 51°52’37’’W ; Eq. Ictiologia UFPA, 5–6 Nov 2000. MZUSP 36792 (3, 106.9– 162.2 mm SL): rio Xingu, Cachoeira do Espelho , 3°39’2’’S, 52°22’46’’W; P.E. Vanzolini, 23–26 Oct 1986 . Mato Grosso: MZUSP 94946 (2, 195.0–325.0 mm SL): Campinápolis , Rio Sucuri, trib. rio Culuene , 13°55’40’’S, 53°17’10’’W ; A. Akama & J.L. Birindelli, 15–22 Jan 2006. MZUSP 91924 (1, 318.0 mm SL): Campinápolis, rio Culuene , below future PCH Paranatinga II, 13°49’S, 53°15’W ; J.L. Birindelli et al., 21 Aug 2006. MZUSP 94962 (3, 247.0–347.0 mm SL): same locality; F.C.T Lima et al., 19–20 May 2007 . MZUSP 94897 (21, 4 skel., 278.0–355.0 mm SL): same locality; L.M. Sousa et al., July 2007 . MZUSP 98119 (13, 311.0–380.0 mm SL): same locality; F.C.T. Lima et al., Oct 2007 . MZUSP 91857 (1, c. 300 mm SL): Córrego do Lício , trib . rio Culuene , below PCH Paranatinga II, 13°50’22’’S, 53°14’59’’W; J.L. Birindelli et al., 21 Aug 2006 . MZUSP 98118 (2, 297.0–336.0 mm SL): Campinápolis, rio Culuene, rio Corgão , at its mouth, 13°48’7’’S, 53°15’0’’W; F.C.T. Lima et al., 4–14 Oct 2007 . MZUSP 98131 (2, 309.0–401.0 mm SL): Campinápolis, rio Culuene, Cachoeira do Adelino , 13°47’50’’S, 53°14’46’’W; F.C.T. Lima et al., 2–14 Oct 2007 . MZUSP 94377 (3, 112.6– 187.3 mm SL): Canarana, lake at fazenda Miriam, rio Culuene , 13°25’48’’S, 53°2’24’’W; F.C.T. Lima et al., 23 May 2007 . MZUSP 56809 (1, 233.6 mm SL): Gaúcha do Norte, rio Xingu, confluence of rio Culuene and rio Sete de Setembro , 12°55’28’’S, 52°49’34’’W; M. Goulding et al., 23 Aug 1984 . MZUSP 103199 (1, 376.0 mm SL): Nova Ubiratã, rio Von den Steinen, fazenda A.R.S., 13°5’35’’S, 54°49’8’’W ; F. A. Machado et al., 21 Jan 2006 . Rio Tapajós basin . Pará: MZUSP 18255 (8, 188.4– 210.1 mm SL); MZUSP 21988 (2, 92.7–117.7 mm SL): São Luís, rio Tapajós , 4°27'S 56°15'W; EPA, 4–8 Nov 1970 . MZUSP 56955 (5, 159.5– 182.3 mm SL); MZUSP 30759 (1, 114.7 mm SL): rio Tapajós , between Itaituba and São Luís, c. 4°23’S, 56°5’W; M. Goulding, Sept–Oct 1983 . MZUSP 58095 (8, 103.2–146.0 mm SL): Itaituba, rio Tapajós above Itaituba (rapids); M. Goulding, 22 Oct 1983 . MZUSP 25585 (1, 175.7 mm SL): rio Tapajós, between National Park headquarters and Ramal Saita , km 67, Parque Nacional da Amazônia , 4°33’S, 56°19’W; J.C. Oliveira, 4–6 Jan 1979 . MZUSP 22026 (8, 99.3–122.9 mm SL): lago da Santa Clara, Monte Cristo, rio Tapajós , c. 4°1’S, 55°39’W; EPA, 6 Dec 1970 . MZUSP 25362 (3, 88.6– 101.0 mm SL): igarapé Mambuaí, bridge at BR-230, Amazônia National Park, rio Tapajós ; J.C. Oliveira, 15–31 Jul 1979 . MZUSP 25452 (1, 94.2 mm SL): rio Tapajós, Porto Flexal, below Amazônia National Park headquarters, c. 4°37’S, 56°18’W; J.C. Oliveira, 15–31 July 1979 . MZUSP 25436 (1, 94.2 mm SL); MZUSP 25437 (1, 84.4 mm SL): Ilha Grande, rio Tapajós , above Amazônia National Park headquarters; J.C. Oliveira, 15–31 July 1979 . MZUSP 18251 (2, 143.3–206.0 mm SL): rio Tapajós , Barreirinha; EPA, Nov 1970 . MZUSP 18287 (5, 123.7– 137.1 mm SL): lake facing Monte Cristo, rio Tapajós ; EPA, 8 Dec 1970 . MZUSP 21876 (1, 95.5 mm SL): Maloquinha, near Itaituba, rio Tapajós ; EPA, 11–13 Nov 1970 . MZUSP 22081 (16, 115.4– 135.3 mm SL): ilha da Barrerinha, rio Tapajós , near São Luís; EPA, 21 Nov 1970 . MZUSP 25504 (1, 139.9 mm SL): Furo do Sandro, rio Tapajós , above Pimental, Amazônia National Park; J.C. Oliveira, 6 Jan 1979 . MZUSP 25619 (2, 126.3–155.0 mm SL): rio Tapajós , between Ramal Saita and igarapé da Boa Vista, Amazônia National Park; J.C. Oliveira, 16 Jan 1979 . MZUSP 29926 (8, 1 cs, 91.0– 103.4 mm SL): rio Tapajós , Pederneiras, below Itaituba; M. Goulding, 14 Oct 1983 . INPA 16410 (2, 146.5– 159.7 mm SL); INPA 7058 (1, 131.5 mm SL): rio Tapajós, Pimental , 4°34’29’’S, 56°15’44’’W; L.H. Rapp Py-Daniel & J. Zuanon, 22–24 Oct 1991 . MZUSP 92804 (1, 134.8 mm SL): Itaituba, rio Tapajós , 4°16’14’’S, 55°58’34’’W; J.L. Birindelli & L.M. Sousa, 7 Nov 2006 . LBP 12871 (3, 147.4–225.0 mm SL): Itaituba, rio Tapajós , 4°33’10’’S, 56°18’00’’W; R. Britzke & CEPTA team, 24 Sept 2011 . INPA 7292 (1, 132.3 mm SL): rio Tapajós (no specific locality); L.H. Rapp Py-Daniel & J. Zuanon, Oct 1991 . INPA 6969 (18, 85.8–129.6 mm SL): rio Tapajós , Pimental (rocky pool); L.H. Rapp Py-Daniel et al., 23 Oct 1991 . INPA 6793 (4, 93.7–144.0 mm SL); INPA 6636 (2, 107.7– 132.3 mm SL): rio Jamanxim , trib . rio Tapajós , Ilha Terra Preta, 4°47’S, 56°24’W; L.H. Rapp Py-Daniel & J. Zuanon, 19–20 Oct 1991 . MZUSP 99926 (3, 85.0– 102.9 mm SL): trib. rio Teles Pires, below Sete Quedas rapids, 9°18’27’’S, 56°47’38’’W; L.M. Sousa & A.L. Netto-Ferreira, 9 June 2008 . MZUSP 99874 (1, 110.3 mm SL): rio Teles Pires, below Sete Quedas rapids, 9°18’42’’S, 56°46’47’’W; L.M. Sousa & A.L. Netto-Ferreira, 9 June 2008 . MZUSP 99564 (1, 42.5 mm SL); MZUSP 99512 (3, 191.7– 192.1 mm SL): rio Teles Pires, near Sete Quedas rapids, 9°20’20’’S, 56°46’30’’W; R. Hilário, 23–25 March 2008 . Mato Grosso: MZUSP 100055 (3, 72.2–101.1 mm SL): Paranaíta, rio Teles Pires, above Sete Quedas , 9°23’53’’S, 56°34’37’’W ; L.M. Sousa & A.L. Netto-Ferreira, 16 June 2008. MZUSP 99996 (2, 94.6–110.9 mm SL): Paranaíta, rio Teles Pires, above Sete Quedas , 9°25’2’’S, 56°33’1’’W ; L.M. Sousa & A.L. Netto-Ferreira, 16 June 2008. MZUSP 99574 (1, 44.3 mm SL): Paranaíta, rio Teles Pires , 9°25’5’’S, 56°32’21’’W ; R. Hilário, 2 April 2008. MZUSP 95620 (14, 97.0–197.0 mm SL): Paranaíta, rio Teles Pires , near ferry at MT-416 road, 9°27’7’’S, 56°30’46’’W ; L.M. Sousa & A.L. Netto-Ferreira, 27 Sept 2007. MZUSP 106177 (8, 250.0–405.0 mm SL): Alta Floresta, rio Cristalino, P.E. do Cristalino , c. 9°27’S, 55°50’W ; S. A . A. Silva, 2004–2006. MZUSP 100017 (1, 120.0 mm SL): Novo Mundo, rio Nhandu (trib. rio Teles Pires ), below Nhandu dam, c. 9°53’S, 55°22’W ; K. de Silimon, 19 Nov 2006. MZUSP 62537 (1, 106.7 mm SL): Alta Floresta, rio Teles Pires, pesqueiro do Dentinho , c. 10°15’S, 55°49’W ; F. A. Machado et al., 29–30 July 1997. MZUSP 62508 (2, 150.5– 174.8 mm SL): Alta Floresta, rio Teles Pires , Porto do Alcindo (1 km below mouth of rio Peixoto de Azevedo ), 9°59'25'’S, 55°33'48'’W; F . A. Machado et al., 29–30 July 1997. MZUSP 96822 (2, 210.0–220.0 mm SL): Peixoto de Azevedo, Cachoeira da Neblina, trib. rio Peixoto de Azevedo , 10°23’10’’S, 54°18’22’’W ; J.L. Birindelli et al., 18 Oct 2007. MZUSP 95866 (2, 157.5– 159.2 mm SL): Itaúba, rio Teles Pires , 10°58’30’’S, 55°44’3’’W ; J.L. Birindelli & P.H. Carvalho, 1 Oct 2007. MZUSP 99135 (1, 290.0 mm SL): Itaúba, rio Renato (trib. rio Teles Pires ), 11°4’24’’S, 55°14’35’’W ; P. Hollanda-Carvalho & S. Lima, 26 Feb 2008. MZUSP 99385 (1, 392.0 mm SL): Itaúba, rio Teles Pires, below mouth of rio Renato , 11°3’44’’S, 55°19’8’’W ; P. Hollanda-Carvalho & S. Lima, 19 Feb 2008. MZUSP 62559 (1, 417.9 mm SL): Sinop, rio Teles Pires , Ilha do Peixeirinho, 11°34’55’’S, 55°38’53’’W: F . A. Machado et al., 1–2 Aug 1997. ZUEC 9190 (1, 345.0 mm SL): Sinop, rio Teles Pires , 11°35’17’’S, 55°39’36’’W ; L. Matos & L.N. Carvalho, 19 Nov 2014. MZUSP 82015 (1, 409.0 mm SL): Lucas do Rio Verde, rio Verde (trib. rio Teles Pires ), 13°3’S, 55°54’W ; K. de Silimon, 16 March 2001. MZUSP 56785 (2, 199.5– 233.6 mm SL): Porto dos Gaúchos, rio Arinos , 11°32’S, 57°25’W ; M. Goulding, 19 Aug 1984. MZUSP 92633 (1, 279.0 mm SL): Sapezal, rio Juruena, below future PCH Telegráfica , 12°41’22’’S, 58°56’47’’W ; K. de Silimon et al., 15 Sept 2006. MZUSP 95506 (1, 271.0 mm SL): Sapezal, rio Papagaio at mouth of rio Buriti , road Sapezal / Brasnorte , 12°47’6’’S, 58°23’5’’W ; F. A. Machado et al., 7–9 Oct 2006. MZUSP 61056 (1, 202.2 mm SL) ; MZUSP 60423 (2, 255.7– 263.5 mm SL): Nova Mutum, rio Arinos , Fervedouro, fazenda Fervedouro, 14°13'10'’S 56°01'43'’W; F.C.T. Lima et al., 18–19 Feb 2000 . MZUSP 61133 (3, 219.3– 247.1 mm SL); MZUSP 61132 (9, 211.9– 434.7 mm SL); MZUSP 91506 (3, 210.0–247.0 mm SL): Nova Mutum, rio Arinos , 14°13’S, 56°2’W; J. M. Mendes, 1999–2000 . MZUSP 67832 (130, 11 cs, 16.9–53.2 mm SL): Nova Mutum, piscicultura Buriti (stocked juveniles); H.F. Mendes, 10 Feb 2000. USNM 194317 (1, 86.5 mm SL); USNM 199204 (3, 151.3– 194.8 mm SL); USNM 194390 (2, 170.9– 177.5 mm SL): “ Upper Juruena-Arinos ” (no precise locality); H. Schultz, 1962. Rio Madeira basin . Rondônia: MZUSP 14028 (6, 104.9– 130.7 mm SL): Cururu, rio Machado , c. 8°13’S, 62°46’W; M. Goulding, April 1978. UF 100614 (1, 207.6 mm SL) : Rio Candeias ca. 2 km above from its mouth, c. 8°38’S, 63°33’’W; J.P. Viana, 14 May 1994 . INPA 16437 (1, 112.1 mm SL): rio Jamari, diverting channel of UHE Samuel (cofferdam), 8°45’S, 63°27’W; G.M. Santos, 7–9 June 1988 . INPA 16413 (6, 257.6– 272.8 mm SL): rio Jamari , below Samuel dam (igapó); G.M. Santos, 27 March 1986 . INPA 16457 (1, 284.8 mm SL): igarapé Japiim, c. 45 km above Samuel dam, c. 9°12’S, 63°13’W; G.M. Santos, 13 June 1985 . INPA 16458 (1, 319.8 mm SL): rio Jamari, above Samuel dam; G.M. Santos, 7 Dec 1984. LBP 5146 (1, 215.0 mm SL): Ji-Paraná , rio Machado , 10°46’36’’S, 61°55’12’’W ; J. Damaceno & W. Troy, 22 Aug 2007. INPA 16459 (1, 325.2 mm SL): Ariquemes, rio Jamari, below rio Canaã mouth, 9°56’S, 63°5’W ; G.M. Santos, 15 Nov 1983. INPA 16363 (6, 110.5– 148.3 mm SL): mouth of rio Guaporé, Surpresa , 11°53’S, 65°1’W ; G.M. Santos, 16 Jun 1984. INPA 16356 (1, 246.0 mm SL): Pimenteiras do Oeste, rio Guaporé , 13°29’S, 61°3’W ; G.M. Santos, 30 Nov 1984. CAS 68857 (1, 241.6 mm SL): Rio Guaporé, Maciel , c. 12°34’S, 63°30’W ; J.D. Haseman, 26 Jul 1909. Mato Grosso: MZUSP 77402 (1, 186.8 mm SL): Panelas, rio Roosevelt , above the rapids, 9°11’17’’S, 60°44’53’’W ; F. A. Machado et al., 17–18 July 1997 . INPA 16389 (3, 161.3– 191.1 mm SL): rio Aripuanã , Lago Genipapo; Eq. Ictiologia / INPA, 20 Aug 1976 . INPA 16412 (5, 102.0– 127.1 mm SL): rio Aripuanã , Ilha do Castanhal; Eq. Ictiologia / INPA, 20 Aug 1976 . INPA 16395 (1, 283.2 mm SL): rio Aripuanã, 3 km below Cachoeira Grande , c. 10°8’S, 59°26’W ; Eq. Ictiologia/INPA, 8 Nov 1976. MZUSP 103036 (1, 290.0 mm SL): Aripuanã, rio Aripuanã , below Salto de Dardanelos, 10°10’6’’S, 59°26’50’’W ; F. A. Machado et al., 17 Sept 2004 . MZUSP 103037 (1, 225.0 mm SL): rio Verde , trib . rio Guaporé , Brazil / Bolivia border, 14°7’36’’S, 60°28’30’’W; O. A. Cantelmo & L. Barbosa, 13–21 Aug 2005 . MZUSP 94990 (2, 230.0–264.0 mm SL): Vila Bela da Santíssima Trindade, rio Guaporé , 15°1’S, 59°49’W; R.O. Mascarenhas et al., 5 Dec 2006. Rio Negro basin . Amazonas: CAS 68836 (2, 116.4– 119 mm SL): market at Manaus; C. Ternetz, Dec 1924 . MZUSP 6136 (1, 162.8 mm SL): rio Negro, above Manaus , c. 3°4’S, 60°16’W; EPA, 22–25 April 1967 . MZUSP 59076 (3, 143.7– 178.4 mm SL); MZUSP 59075 (1, 202.7 mm SL); MZUSP 59078 (1, 215.0 mm SL); MZUSP 59081 (1, 240.8 mm SL); MZUSP 59087 (2, 100.6– 196.5 mm SL): Anavilhanas, Lago do Prato; G. Borges, May 1981 – June 1982. MZUSP 59084 (1, 190.0 mm SL): rio Negro, Anavilhanas, lago Xilauá (igapó); G. Borges, Aug 1981. MZUSP 56782 (3, 182.8–200.0 mm SL) ; MZUSP 59083 (4, 102.0– 120.3 mm SL); MZUSP 59082 (1, 102.3 mm SL); MZUSP 59073 (10, 89.4– 114.7 mm SL): rio Negro, Anavilhanas , c. 2°43’S, 60°41’W; M. Goulding, Oct 1979 – Dec 1980. MZUSP 59077 (1, 188.0 mm SL): Anavilhanas , rio Negro, Lago Camauiri (igapó): G. Borges, July 1981 . MZUSP 59079 (1, 132.8 mm SL): rio Negro, Anavilhanas; G. Borges, Oct 1981 . MZUSP 27333 (4, 81.1–96.4 mm SL): Ayrão Velho, mouth of rio Padauari , rio Negro, 2°6’S, 61°13’W ; L.P. Portugal, 8 Nov 1982. MZUSP 27328 (1, 104.8 mm SL): Moura, Pedra do Gavião , rio Negro, c. 1°27’S, 61°38’W ; L.P. Portugal, 13–14 Nov 1982 . MZUSP 17658 (1, 178.0 mm SL): Rio Jauaperi (trib. rio Negro), c. 1°16’S, 61°36’W; T.R. Roberts, Nov 1968 . MCP 46478 (1, 26.3 mm SL): igarapé Cambeua (trib. Rio Jauaperi), 1° 30’53’’S, 61° 27’33’’W ; P. Petry, 28 Jan 2011. MZUSP 59074 (9, 91.6–113.9 mm SL): rio Negro, Cachoeira do Buiu-Açú , c. 0°30’S, 64°50’W ; M. Goulding, Oct 1979. MZUSP 45526 (1, 103.3 mm SL): rio Negro, Tapera , c. 0°12’S, 64°4’W ; EPA, 1 Nov 1972. MZUSP 59086 (2, 144.7–206.0 mm SL): rio Negro, below rio Daraá (rapids), c. 0°27’S, 64°44’W ; M. Goulding, 16 Feb 1980. MZUSP 59080 (1, 285.3 mm SL): igarapé do Acará, São Pedro (igapó), c. 0°21’S, 66°36’W ; M. Goulding, May 1979. LBP 6878 (2, 82.2–93.7 mm SL): São Gabriel da Cachoeira , rio Negro, 0°8’ 9’’ S, 67°05’3’’ W ; C. Oliveira et al., 11 Aug 2008. MZUSP 91576 (3, 127.1– 138.1 mm SL): Rio Uaupés (no precise locality); J. Chernella, no date . MZUSP 91493 (1, 226.0 mm SL): Rio Tiquié, between Caruru and Boca de Sal villages, 0°16’N, 69°54’W; M.C. Lopes, 2001– 2002 . Rio Branco basin , Roraima: MZUSP 59085 (6, 120.8– 202.9 mm SL): Marará, rio Branco ; M. Goulding, 26 Oct 1979. USNM 202716 (1, 231.4 mm SL): Rio Xeruini, c. 60 km above mouth, c. 1°55’S, 61°55’W ; M.R. Brittan, 28 April 1964. MZUSP 56944 (1, 198.1 mm SL); MZUSP 59621 (3, 207.9– 252.6 mm SL); MZUSP 56807 (10, 203.2– 273.9 mm SL): rio Branco, cachoeira do Bem Querer , 1°55’N, 61°1’W; M. Goulding, 6–9 Jan 1984 . MZUSP 29925 (1, 90.8 mm SL); MZUSP 56778 (1, 200.3 mm SL): igarapé 2 km above Cachoeira do Bem Querer, rio Branco ; M. Goulding, 9 Jan 1984 . MZUSP 29924 (2, 84.6–86.8 mm SL): igarapé do Bota-Panela, near Cachoeira do Bem Querer, rio Branco ; M. Goulding, 9 Jan 1984 . MZUSP 17756 (3, 122.9– 134.4 mm SL): igarapé do Pau Roxo, trib. rio Uraricoera , Fazenda Canadá; T.R. Roberts, 18 Feb 1969 . MZUSP 56781 (2, 211.4– 233.9 mm SL); MZUSP 29927 (5, 107.9– 116.7 mm SL): Igarapé do Cujobim, rio Branco, facing ilha de Maracá , c. 3°22’N, 61°22’W; M. Goulding, 13 Jan 1984 . INPA 16388 (1, 169.0 mm SL): rio Mucajaí, c. 1 km below Paredão , 2°56’47’’N, 61°34’34’’W; M. Jégu & E. Ferreira, 4 Oct 1986 . INPA 16394 (1, 262.6 mm SL): rio Mucajaí, c. 2 km above Paredão , 2°56’20’’N, 61°37’14’’W; M. Jégu & E. Ferreira, 3 Oct 1986 . Other river systems: Brazil, Amazonas: MZUSP 99213 (1, 117.0 mm SL): Lago Urini, mouth of rio Japurá , c. 2°9’S, 65°9’W; R.B. Barthem, 30 Sept 1979 . MCP 29771 (1, 121.1 mm SL): Maraã, Lago Amanã, mouth of igarapé Uxi , 2°32’47’’S, 64°40’10’’W; W.G.R. Crampton, 14 Dec 1997 . MCP 29776 (1, 120.6 mm SL): Maraã, Lago Amanã, mouth of igarapé Uxi , 2°37’4’’S, 64°40’1’’W; W.G.R. Crampton, 1 Dec 1998 . MCP 29774 (1, 128.1 mm SL): Maraã, Lago Amanã, mouth of rio Baré , 2°28’28’’S, 64°43’20’’W; W.G.R. Crampton, 15 Nov 1998 . MCP 29775 (2, 128.9– 131.6 mm SL): Maraã, Lago Amanã, mouth of rio Baré , 2°27’23’’S, 64°43’35’’W ; W.G.R. Crampton, 13 Dec 1997. MZUSP 17592 (1, 42.5 mm SL): rio Içapó, at mouth of rio Jutaí , c. 2°47’S, 66°49’W ; EPA, 22 Oct 1968. MZUSP 17530 (8, 72.2–134.4 mm SL): Santo Antônio do Içá, igarapé da Cachoeira, Cuiauá , trib . rio Içá, c. 3°6’S, 67°57’W; EPA, 18 Oct 1968 . MNRJ 21470 (1, 146.0 mm SL): rio Queixito at mouth of rio Javari , 4°25’48’’S, 70°15’38’’W; A. Parko, 1952 . Peru, Depto. Loreto: INHS 106468 (2, 97.1–134.4 mm SL) ; INHS 106470 (6, 93.5–119.2 mm SL): Río Nanay, Pampa Chica , 3°45’1’’S, 73°17’0’’W; M.H. Sabaj et al., 22–27 Jul 1997. Bolivia, Depto . Beni , Rio Madeira basin: UMMZ 204246 (2, 164.1– 247.3 mm SL) ; UMMZ 204394 (1, 217.2 mm SL); UMMZ 204201 (1, 98.0 mm SL); UMMZ 204445 (2, 89.9–90.6 mm SL); UMMZ 204930 (1, 91.2 mm SL); UMMZ 204417 (1, 80.4 mm SL); UMMZ 204408 (2, 152.4– 204.1 mm SL); UMMZ 204649 (1, 251.0 mm SL): Río Itenez (= Rio Guaporé), near Costa Marques, 12°27’S, 64°14’W; R.M. Bailey et al., Aug– Oct 1964 . MNHN 1989-1429 (3, 120.2– 146.2 mm SL): Río Itenez, Boca Machupo , c. 12°27’S, 64°22’W; L. Lauzanne & G. Loubens, no date.

Figures

FIGURE 84. Brycon falcatus, BMNH 1849.4.8: 42, 49, 92.7 mm SL: Brazil, Pará, rio Capim. Syntype of Brycon brevicauda Günther.

FIGURE 85. Brycon falcatus, ANSP 69619, 149.2 mm SL: Brazil, “ Rio Parnahyba … Piauhy ”. Holotype of Brycon matrinchao Fowler. Photo by M. W. Littmann.

FIGURE 86. Brycon falcatus, ANSP 176667, 165.3 mm SL: Guyana, Burro Burro River (trib. Essequibo River). Photo by M. H. Sabaj Pérez.

FIGURE 87. Brycon falcatus, MZUSP 18077, 135.3 mm SL: Brazil, Pará, igarapé do Limão.

FIGURE 88. Brycon falcatus, MZUSP 61056, 202.2 mm SL; Brazil, Mato Grosso, rio Arinos.

FIGURE 89. Brycon falcatus, MZUSP 48113, 197.7 mm SL: Brazil, Goiás, rio Araguaia.

FIGURE 90. Brycon falcatus, MZUSP 98119, 310.0 mm SL: Brazil, Mato Grosso, rio Culuene (freshly collected). Photo by C. R. Moreira.

FIGURE 91. Brycon falcatus, MZUSP 61132, 434.7 mm SL: Brazil, Mato Grosso, rio Arinos.

FIGURE 92. Brycon falcatus, MZUSP 103036, 290.0 mm SL: Brazil, Mato Grosso, rio Aripuanã.

FIGURE 93. Brycon falcatus, MZUSP 56782, 200.0 mm SL: Brazil, Amazonas, rio Negro.

FIGURE 94. Brycon falcatus, INHS 61479, 113.5 mm SL: Venezuela, Apure, Caño San Miguel.

FIGURE 95. Brycon falcatus, ANSP 161212, 111 mm SL: Venezuela, Depto. Amazonas, Río Ventuari. Photo by M. H. Sabaj Pérez.

FIGURE 96. Brycon falcatus, MZUSP 17530, 122.4 mm SL: Brazil, Amazonas, rio Içá basin.

FIGURE 97. Brycon falcatus, INHS 43928, 134.4 mm SL: Peru, Loreto, Río Nanay.

FIGURE 98. Brycon falcatus, MZUSP 91493, 226.0 mm SL: Brazil, Amazonas, rio Tiquié.

FIGURE 99. Map of northern South America, showing known localities of Brycon falcatus (red dots).

Tables

TABLE 23. Absolute frequency of lateral-line scales among distinct Brycon falcatus populations.

	47	48	49	50	51	52	53	54	55	56	57
Guyana and Suriname	1	1	2	1	5	10	12	12	6	4	2
Orinoco						1	5	2	5	3	3
Negro				1	1	3	5	3	4	6	9
Branco					1		4	5	4	4	4
Tocantins and Capim						1	2	1	1	1	4
Xingu							2	4	5	10	13
Tapajós						2	3	5	9	13	10
Madeira							2	4	7	6	8
Western Amazon							2	1	2	4	4
continued.