Brycon melanopterus (Cope, 1871)

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 : 134-141

Brycon melanopterus (Cope, 1871)

( Figs. 78–82 )

Megalobrycon melanopterum Cope, 1872: 262 –263, pl. 13, fig. 1 (Type locality: “Ambyiacu”).

Brycon (Megalobrycon) melanopterum: Steindachner, 1876: 590 (“Amazonenstrome”).

Brycon melanopterum: Fowler, 1907: 447 (syntypes, redescription); Amaral Campos, 1950: 142 –143 (in part: rio Tapajós); Géry & Mahnert, 1984: 174, 176, fig. 4 (Peru: Rio Mazan, trib. Rio Napo).

Brycon melanopterus: Eigenmann, 1910: 430 (name amendment); Knöppel, 1970: 268 (Lago Calado, Central Amazon; short description; diet); Howes, 1982: 34 (literature compilation); Ortega & Vari, 1986: 7 (Peru; common name); Barriga, 1991: 14 (Ecuador; common name); Géry & Mahnert, 1992: 794 –800, 802, figs. 1 (upper), 5 (Central Amazon; diagnosis; common name; comparison with B. cephalus [= B. amazonicus ]); Barriga, 1994: 28 (Parque Nacional Yasuní, rio Napo, Ecuador); Crampton, 1999: 15, 26 (Lago Mamirauá, Alvarães, Amazonas: habitat preferences, diet, common name); Barthem, 1999: 82 (fisheries, common name; Alvarães and Tefé, Central Amazon); Bayley, 1988: 131 –133, 136 (in part; rio Solimões floodplains, Manaus area; growth rates of young specimens related to density and seasonality); Mérona & Rankin-de-Mérona, 2004: 77 (Lago do Rei, Ilha do Careiro, Rio Amazonas: diet); Santos et al., 2006: 38 (retouched picture; description, biology, common name, fishery importance; Manaus area); Bejarano et al., 2006: 362 (Río Mesay, Río Caquetá drainage, Colombia: abundance); Blanco-Parra & Bejarano-Rodríguez, 2006: 856 –857 (Río Mesay, Río Caquetá drainage, Colombia: diet, reproduction); Galvis et al., 2006: 190 –191, 457 (Colombia, Rio Amazonas, Leticia; photograph; drawing; short description); Lima et al., 2013: 230 –231 (Brazil, Rondônia, rio Madeira basin; distribution in the rio Madeira basin, short description, photo); Correa & Winemiller, 2014: 214, 217, 219, 220, 221 (Colombia, Depto.Vaupés, Río Apaporis: seasonal variation in diet, diet breadth and overlap with other frugivore fishes).

Brycon hilarii (not Valenciennes, in Cuvier & Valeciennes): La Monte, 1935: 7 (“Jurua”; material collected by B. Krukoff, examined).

Brycon melampterum (sic): Eigenmann & Allen, 1942: 253 –254 (Peru: Yarinococha; Orellana, Rio Ucayali; Rio Pachitea; Pto. Bermudez, Rio Pichis; mouth of Río Pacaya).

Brycon cf. melanopterus: Goulding, 1980: 73 –75, fig. 4.7 (diet, migrations, breeding; rio Machado, Rondônia). [not Braum, 1983a: 355 –371; Braum, 1983b: 268 –269; Werder, 1983: 445 –461; Junk et al., 1983: 408, 414, 426–427; Werder & Soares, 1984: 398 –416; Lasso, 1992: 11, 22, fig. 2; Piedade et al., 2006: 1176].

Brycon sp.: Piedade et al., 2006: 1176 (ingestion of Astrocaryum jauari fruits in the lower Rio Negro, Brazil).

Brycon cephalus (not Günther): Galvis et al., 2006: 457 (photo).

Diagnosis. The presence of an oblique, solid dark stripe extending from immediately behind pelvic-fin basis, through anal-fin basis, lower surface of caudal peduncle, middle area of caudal peduncle, to the upper caudal-fin lobe, diagnoses Brycon melanopterus from all remaining Brycon species, with the exception of B. falcatus and B. amazonicus . Brycon melanopterus can be diagnosed from the often sympatric B. amazonicus by possessing dark, straight 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), oblique dark stripe continuous and solid dark (vs. oblique stripe, when present, blurred and not continuous), and paired fins clear (vs. paired fins black). Brycon melanopterus is more similar to B. falcatus , and an unequivocal diagnosis between both species is not possible due to the great polymorphism observed in the latter 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 ). Additionaly, Brycon melanopterus is typically a more elongated fish, with higher vertebrae counts. See item “Comparisons”, below, for a more detailed comparison with Brycon falcatus .

Description. Morphometric data are presented in Table 20 . Middle-sized species, largest examined specimen 289.1 mm SL. Body moderately slender to moderately 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 slightly convex from latter point to basis of supraoccipital process, moderately 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 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 pointed, 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.

Seven (2), 8 (7), 9 (12), 10 (31), 11 (14), 12 (13), or 13 (7) relatively small tricuspidate teeth in outer series. Four (26), 5 (48), 6 (15), or 7 (2) tri- to pentacuspidate teeth in second, inner premaxillary row, plus 3 (21), 4 (61), or 5 (9) 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 26 maxillary teeth, slightly smaller than teeth of first premaxillary row, anterior teeth tricuspidate, posterior teeth unicuspidate. Dentary with 8 (3), 9 (8), 10 (17), 11 (8), 12 (8), 13 (4), or 14 (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 21–24 small, aciculated, unicuspidate teeth, originating on lingual crest of dentary replacement trench at the level of fifth to sixth main series dentary teeth.

Scales cycloid. Lateral line complete, from supracleithrum to caudal-fin base. Fifty-four (1), 56 (2), 57 (1), 60 (1), 61 (8), 62 (8), 63 (13), 64 (9), 65 (19), 66 (14), 67 (7), 68 (5), or 70 (2) 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 11 (2), 12 (20), 13 (56), 14 (10), or 15 (2). Horizontal scale rows between lateral line and pelvic-fin 5 (8), 6 (46), 7 (32), or 8 (4). Circumpeduncular scales 18 (1), 19 (12), 20 (20), 21 (31), 22 (21), or 23 (5).

Dorsal-fin rays ii, 9. Dorsal fin origin slightly ahead middle of SL. First dorsal-fin pterygiophore inserting behind neural spine of 12th (1) vertebra. Anal-fin rays iii (not including first, small unbranched ray only visible in cs specimens), 19 (3), 20 (2), 21 (11), 22 (29), 23 (27), 24 (13), or 25 (2). First anal-fin pterygiophore inserting behind haemal spine of 24th (1) vertebra. Anal-fin rays decreasing only slightly in size towards anal-fin end. Sheath of scales covering basis of anal-fin rays composed of four scale rows, lower scale row formed by 19–23 rectangular scales. Pectoral-fin rays i, 11 (1), 12 (28), 13 (51), or 14 (11). Pelvic-fin rays typically i, 7 (87), rarely i, 5 (10), or i, 8 (3). Main caudal-fin rays 10/9. Caudal fin forked. 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.

Four branchiostegal rays, three on anterior ceratohyal and one on posterior ceratohyal. First branchial arch with 11 (5), 12 (6), 13 (12), 14 (4), or 15 (5) lower, 1 at angle, and 9 (2), 11 (8), 12 (15), 13 (6), or 14 (2) upper gill rakers. Vertebrae 45 (2). Supraneurals 9 (1).

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, and opercle silvery in specimens that retained 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 that retained 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 fifth to sixth lateral line scales, and vertically one and half scales high. Scales on lateral portions of body with dark pigment concentrated on their central portion, forming dark, straight longitudinal stripes, more conspicuous dorsally. Series of irregular, narrow vertical stripes present in small (up to 100 mm SL) specimens. Dark, solid, oblique dark stripe extending in most specimens from immediately behind pelvic-fin basis, through anal-fin basis, lower surface of caudal peduncle, middle area of caudal peduncle, to the upper caudal-fin lobe. Some specimens (most of them obviously faded) with dark stripe starting only at anal-fin origin. Lower caudal-fin rays, dorsal and anal-fins clear, with a variable amount of interradial dark pigmentantion. Adipose-fin light- to dark-grey.

Color in life. Based on pictures of specimens collected in tributaries of the Rïo Ucayali at Zona Reservada Sierra del Divisor, Ucayali, Río Pacaya, Reserva Nacional Pacaya Samíria, Loreto, Peru, and Río Mesay, Río Caquetá basin, Colombia. Snout and top of head grey. Overall gound color clear, with a silvery hue, coppery on dorsum. Oblique dark stripe extending from pelvic-fin basis to upper lobe of caudal fin very conspicuous. Adipose fin and middle caudal-fin rays with some yellowish pigmentation, remaining fins translucent.

Common names. Brazil: “ matrinchão ”, rio Madeira basin, Rondônia; “jatuarana”, Manaus and Tefé regions, Amazonas ( Goulding, 1980; Borges, 1986; Géry & Mahnert, 1992; Crampton, 1999; Santos et al., 2006). Both names are also applied, but with an inverse usage, to Brycon amazonicus on those same regions (see under “Common names” of B. amazonicus ). Tefé region: “gogota” ( Crampton, 1999: 15; Barthem, 1999: 82). Ecuador: “sábalo” (Barriga, 1991: 14). Peru: “sábalo cola negra” ( Ortega & Vari, 1986: 7).

Distribution. Widespread in western Amazon, at the main channel of the Rio Amazonas /Solimões upstream to Río Ucayali in Peru, Río Napo in Ecuador, and Río Caquetá in Colombia, rio Madeira system upstream to the rio Madre de Dios in Peru, and lower rio Negro and rio Branco systems in Brazil ( Fig. 83 ). Additionally, Géry & Mahnert (1992: 798, fig. 5) portrays a Brycon melanopterus specimen collected in the rio Guaporé at Vila Bela (da Santíssima Trindade), in the upper rio Madeira basin at Mato Grosso state, Brazil.

Comparisons. As noticed in the Diagnosis, an unequivocal diagnosis between Brycon melanopterus and B. falcatus is not possible due to the great range of pigmentary and morphological variation observed in the latter species. While typically Brycon falcatus does not possess a solid oblique dark bar extending from pelvic-fin basis to the upper lobe of caudal peduncle as B. melanopterus , presenting instead a black stripe on anal-fin basis not continuous with a V-shaped blotch on caudal-fin and caudal peduncle, some populations of Brycon falcatus possess a color pattern similar or almost identical to B. melanopterus . Brycon melanopterus and B. falcatus are however largely alopatric, occurring sympatrically only at the western Amazon (where B. falcatus is very local) and at the lower rio Negro and rio Branco basins. Populations of Brycon falcatus from western Amazon in Brazil and Peru, sympatric and in some cases collected syntopically with B. melanopterus (INHS 106468, INHS 106470, MZUSP 17530, MZUSP 99213), are very similar to the latter species since they have a reduced amount or lack entirely dark pigmentation on the lower caudal-fin lobe. However, unlike Brycon melanopterus , these specimens possess what could be called an interrupted oblique dark stripe, since the blotch in the caudal peduncle and caudal fin is not continuous with the dark stripe at the basis of anal fin (compare Figs. 5 I and L). Also, although there is a great overlap in morphometric data, Brycon melanopterus is generally a more elongated fish (28.6–39.7, mean 32.5 % of SL, vs. 28.8–42.8, mean 36.4 in B. falcatus ), with a shallower head (73.8–91.3, mean 82.3 % of HL, vs. 76.7–1.14, mean 90.6 in B. falcatus ) than B. falcatus . The fact that Brycon melanopterus is more elongated than B. falcatus is also reflected in its higher vertebrae counts when compared with the latter species (45, n = 2, vs. 39–44, modally 41, n = 17, respectively). Populations of Brycon falcatus inhabiting the upper rio Negro basin in Brazil and the upper rio Orinoco basin in Venezuela possess a color pattern that is virtually undistinguishable from the one presented by B. melanopterus , i.e., the oblique bar is continuous from pelvic-fin basis/anal-fin origin to upper lobe of caudal fin. These specimens (MZUSP 91493, MZUSP 91576, FMNH 104026, ANSP 161210, AMNH 93064, AMNH 93065) are here assigned to Brycon falcatus due to the fact that in overall body shape and vertebrae counts they agree more with the latter species than with B. melanopterus . Brycon melanopterus is apparently absent from the upper rio Negro above the São Gabriel da Cachoeira rapids (0°8’S, 67°5’W), and specimens of the species collected in the lower rio Negro and at the rio Branco are morphologicaly undistinguishable from specimens from the Rio Amazonas /Solimões/ Ucayali and rio Madeira basins. Sympatric populations of Brycon falcatus in the middle and lower rio Negro basin can be readily distinguished from B. melanopterus by possessing dark pigmentation on the lower caudal-fin lobe (though considerably less intense than the dark pigmentation in the upper caudal-fin lobe), and, as all remaining Brycon falcatus populations, by not possessing an oblique dark stripe, i.e., the caudal peduncle/ caudal fin blotch is not continuous with the dark stripe at the basis of anal fin.

Ecological notes. Goulding (1980) and Borges (1986) presented information on the ecology of Brycon melanopterus , from respectively the rio Machado (rio Madeira basin, Rondônia state, Brazil) and rio Negro (Amazonas state, Brazil). Goulding (1980: 73–75) reported that the species is less abundant and does not grow as large as the sympatric Brycon amazonicus (his Brycon sp.). Dietary itens found in five stomachs included crushed seeds of Tabebuia barbata (Bignoniaceae) , Hevea brasiliensis (Euphorbiaceae) , and Mabea sp. ( Euphorbiaceae ), as well as terrestrial arthropods and a fish. Since the fishermen does not report schools of Brycon melanopterus moving in the rio Machado and rio Madeira, Goulding (1980) infered that the species does not undertake longrange, massive reproductive migrations. Borges (1986) reported fruits and seeds as the dominant dietary item in specimens of Brycon melanopterus (his Brycon cf. cephalus ) collected in the rio Negro, followed by arthropods, leaves, flowers, mammals and faeces. Mérona & Rankin-de-Mérona (2004: 77) noticed a similar dietary preference for specimens of Brycon melanopterus collected in a floodplain lake in the Amazon river. Among the fruits and/or seeds ingested in the rio Negro by the species, the most abundant were those belonging to the family Euphorbiaceae (notably Alchornea schomburgkiana ), but also Annonaceae (mainly Pseudoxandra polypheba ), Lauraceae ( Ocotea sp.), and Leguminosae ( Centrosoma sp. and Swartzia sp.) ( Borges, 1986). 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.

Remarks. Cope (1871: 262–263) described Megalobrycon melanopterum based on two specimens collected by J. Hauxwell at the “Ambyiacu”, in his words “an inconsiderable river, which empties into the Amazon near to Pebas, in Eastern Ecuador, some distance east of the Napo”. Currently, the Río Ampyiacu (not “Ambyiacu”) lies in the Departamento Loreto in Peru. Fowler (1907: 447) redescribed the species, based on the type specimens and additional specimens collected by J. Orton (ANSP 21972). He cited the two “co-types” (= syntypes), and designated the largest specimen (ANSP 8035) as the “type” of the species, which can be accepted as a designation of a lectotype (ICZN, 1999, articles 74.3 and 74.5). The identification of the specimens ANSP 8035 and ANSP 8036 as being, respectively, the holotype and paratype of Megalobrycon melanopterum , made by Böhlke (1984: 51) and subsequently followed by some other authors ( Eschmeyer, 1998: 1055; Lima, 2003: 177) is thus incorrect, and these specimens should be henceforward referred as the lectotype and paralectotype of the species. The good illustration of the species present in the original description (Cope, 1871; pl. 13, fig. 1) depicts quite well the oblique, continuous dark stripe extending from anal-fin basis to the upper lobe of caudal fin typical for the species. Possibly due to this fact, and relatively unusually in the history of taxonomy of Brycon , the name B. melanopterus was generally correctly employed in the literature (e.g., Eigenmann & Allen, 1942; Knöppel, 1970; Goulding, 1980; Géry & Mahnert, 1984, 1992). However, a few misidentifications have occurred in the literature, mainly involving Brycon amazonicus , a largely sympatric species which occasionaly also displays an oblique dark stripe similar to B. melanopterus (see item “Variation” and “Remarks” from B. amazonicus ). For example, the examination of the lot identified by Amaral Campos (1950: 142–143) as Brycon melanopterum (MZUSP 3574) revealed that it was actually composed by both B. melanopterus and B. amazonicus . Also, Howes (1982: 20) incorrectly supposed that the specimen identified by Goulding (1980: 74, fig. 4.7) as Brycon melanopterus was a misidentification of B. amazonicus (his B. cephalus ), when in fact Goulding (1980) has correctly identified the species.

Material examined. Type material: ANSP 8035 (1, 142.6 mm SL): “ Ecuador, Ambyiacu River ” [= Peru, Depto. Loreto, Río Ampyiacu , trib. Río Amazonas , c. 3°21’S, 71°47’W]; J. Hauxwell, no date. Lectotype of Megalobrycon melanopterum Cope , designated by Fowler (1907: 447).

Non types. Brazil, Amazonas state, rio Amazonas / Solimões basin: MCZ 21088 (1, 152.4 mm SL): Lago Máximo , near Parintins , 2°40’S, 56°45’W; L. Agassiz et al., 27–30 Aug 1865 . MZUSP 13429 (1, 280.6 mm SL): Itacoatiara , rio Amazonas, c. 3°9’S, 58°27’W; N. Smith, 29 Sept 1977 . MNHN 1996-1087 (1, 171.5 mm SL): Rio Urubu, cachoeira Lindóia , c. 2°37’S, 59°22’W; M. Jégu, 23 Sept 1993 . MZUSP 6090 (1, 181.2 mm SL): lago Puraquequara, rio Puraquequara mouth, 3°2’S, 59°47’W; EPA, 17–19 Apr 1967 . INPA 16366 (1, 167.5 mm SL): rio Amazonas, Paraná do Rei, Ilha do Careiro, c. 3°6’S, 59°49’W ; C. Cox Fernandes, 17 Sept 1986. INPA 16372 (3, 86.1–185.1 mm SL); INPA 16385 (2, 119.8– 127.2 mm SL): rio Amazonas, Ilha do Careiro, c. 3°6’S, 59°49’W ; –Eq. Ictiologia/INPA, June–Oct 1986. MCZ 21087 (1, 127.8 mm SL): Paraná do Janauari, 3°12’S, 60°5’W ; L. Agassiz, 27–29 Oct 1865. USNM 306848 (5, 70.2–101.8); USNM 309178 (1, 124.7 mm SL): Lago Janauari , c. 3°12’S, 60°5’W; P. Bayley, June–July 1977 . INPA 13298 (3, 30.3–52.2 mm SL); INPA 13304 (3, 47.5–65.4 mm SL); INPA 16353 (2, 61.8–67.7 mm SL; INPA 13322 (8, 47.3–66.0 mm SL): rio Solimões , Ilha da Marchantaria, c. 3°14’S, 59°55’W ; P. Petry & R. Sotero, Jan 1993. INPA 16347 (5, 89.0– 97.1 mm SL); INPA 16453 (2, 44.6–58.2 mm SL): rio Solimões , Ilha da Marchantaria, c. 3°14’S, 59°55’W ; Eq. Ictiologia/INPA, 1976–1981. USNM 307013 (1, 73.1 mm SL); USNM 307012 (1, 73.1 mm SL); USNM 307011 (2, 68.9–75.9 mm SL); USNM 307005 (3, 57.4–74.8 mm SL); USNM 229140 (2, 67.8–75.7 mm SL): Ilha da Marchantaria, c. 3°14’S, 59°55’W ; P. Bayley, Jan–Apr 1978. MZUSP 18693 (1, 129.2 mm SL); MZUSP 18699 (1, 46.7 mm SL): Lago Janauacá and surroundings, rio Solimões , c. 3°24’S, 60°17’W; Alpha Helix Exp., Sept 1976 — Jan 1977. MZUSP 75566 (3, 93.3– 106.8 mm SL); USNM 307073 (3, 99.8–121.4 mm SL); USNM 229075 (1, 115.2 mm SL): Lago Murumuru, into Lago Janauacá , c. 3°24’S, 60°17’W; P. Bayley, 28 Sept 1977 . MCP 27932 (1, 70.5 mm SL): Lago Murumuru, into Lago Janauacá , c. 3°24’S, 60°17’W; P. Bayley, 31 Aug 1977 . MZUSP 6626 (12, 110.3– 132.7 mm SL): igarapé trib. lago Manacapuru , c. 3°19’S, 60°50’W; EPA, 13 Nov 1967 . MZUSP 5880 (1, 241.6 mm SL): Lago Manacapuru , c. 3°19’S, 60°50’W; EPA, 26–27 March 1967 . MCZ 21095 (1, 153.2 mm SL): Lago Grande de Manacapuru , 3°6’S, 61°30’W; W. James, Nov–Dec 1865 . MCZ 21085 (2, 122.1–213.0 mm SL): Rio Solimões at Tefé , 3°24’S, 64°45’W; L. Agassiz et al., Oct 1865 . MCP 29772 (1, 123.8 mm SL): Tefé, mouth of igarapé Açu , 3° 24’52’’S, 64° 48’7’’W; W.G.R. Crampton, 21 Jan 1999 . MCP 29773 (1, 118.9 mm SL): Alvarães, Lago Mamirauá, comunidade Boca do Lago Mamirauá , 3° 6’37’’S, 64° 47’49’’W; W.G.R. Crampton, 1 Nov 1997 . MCP 29974 (2, 142.8– 148.5 mm SL): Alvarães , between Lago Secretário and Lago Mamirauá channel, 3° 6’58’’S, 64°47’49’’W; W.G. R.

Crampton, Oct 1993. INPA 19117 (1, 119.3 mm SL); MCP 29975 (1, 136.2 mm SL): Lago Amanã, mouth of igarapé Baré , 2°28’S, 64°43’W; W.G.R. Crampton , 18 Dec 1997. MZUSP 17616 (2, 221.0–235.0 mm SL): igarapé n°1, Fonte Boa , 2°30’S, 66°4’W; EPA , 25 Oct 1968. MZUSP 56498 (3, 146.9–177.0 mm SL): igarapé da Cachoeira, Cuiauá , rio Içá, left margin, c. 3°0’S, 69°2’W; EPA , 18 Oct 1968. MZUSP 27331 (1, 104.4 mm SL): Tabatinga, rio Solimões, Lago Caial , c. 4°21’S, 69°52’W; L.P.S. Portugal , 8 Oct 1982. Amazonas state, rio Uatumã basin: INPA 16409 (1, 184.1 mm SL): igarapé Água Branca, trib. rio Pitinga (trib. rio Uatumã ), c. 0°52’S, 59°27’W; Eq. Ictiologia / INPA , 17 April 1983. INPA 16355 (2, 194.6–267,0 mm CP), Balbina, cachoeira do Boto; Rômulo & Walter, 29 Oct 1987. INPA 5510 (1, 236.4 mm SL): rio Uatumã , Água Branca; S. Amadio , May 1985. Amazonas state , rio Negro basin: INPA 15730 (1, 174.2 mm SL): rio Tarumã-Açú, igarapé Tarumãzinho , BR- 174, km 28, 2°43’51’’S, 60°4’88’’W ; A. Kirovsky, 10 Sept 1993. MZUSP 6191 (3, 192.7– 208.9 mm SL): igarapé Jaraqui, trib . rio Negro, above Manaus; EPA , 22–24 April 1967. MZUSP 56810 (1, 148.4 mm SL): Anavilhanas, Lago do Prato , Paraná, c. 2°45’S, 60°48’W; G. Borges , Sept 1981. MZUSP 57032 (1, 144.1 mm SL); MZUSP 57031 (13, 230.1– 274.9 mm SL): Anavilhanas , rio Negro, c. 2°51’S, 60°38’W; G. Borges , May 1982. MZUSP 56783 (1, 228.3 mm SL): rio Negro, Anavilhanas (igapó), c. 2°51’S, 60°38’W; M. Goulding , May 1980. MZUSP 56786 (2, 144.6– 161.7 mm SL): Anavilhanas , igapó, c. 2°51’S, 60°38’W; G. Borges , March 1981. INPA 16378 (2, 163.8– 170.9 mm SL): rio Negro, Ponta da Piraíba ; Eq. Ictiologia/ INPA , 15 Aug 1985. Amazonas state, rio Madeira basin: MZUSP 58693 (3, 120.0– 140.3 mm SL): rio Canumã , c. 4°2’S, 59°6’W; EPA , 28–29 Nov 1967. Amazonas state, rio Juruá basin: AMNH 12553 (1, 210.2 mm SL): mouth of rio Envira (trib. Rio Tarauacá), near Envira , 7°30’S, 70°4’W; B . A. Krukoff, 1935 . Rondônia state, rio Madeira basin: MZUSP 14027 (2, 219.2– 273.1 mm SL): Lago Cururu, rio Machado , c. 8°4’S, 62°53’W; M. Goulding , April 1978. INPA 16446 (3, 202.2– 247.7 mm SL): rio Jamari, below Samuel dam (igapó), c. 8°38’S, 63°31’W; G.M. Santos , 27 March 1986. INPA 16441 (1, 289.1 mm SL); INPA 16445 (1, 234.0 mm SL): rio Jamari, above Samuel dam, c. 9°30’S, 63°7’W; G.M. Santos , Dec 1984. INPA 16360 (1, 149.3 mm SL): rio Jamari , c. 5 km above Samuel dam; G.M. Santos , 14 June 1988. INPA 16434 (1, 200.8 mm SL): rio Machado, c. 20 km below Ji-Paraná , c. 10°46’S, 61°54’W; G.M. Santos , 3 Jul 1984. Mato Grosso state, rio Madeira basin: MZUSP 60398 (1, 146.0 mm SL): Aripuanã, rio Aripuanã , ferry on road Colniza / Panelas , 9°34’45’’S, 59°25’19’’W; F . A. Machado et al. , 22–23 July 1997. MZUSP 77403 (1, 128.8 mm SL): Panelas, rio Roosevelt , above falls, 9°11’S, 60°44’W; F. A. Machado et al. , 17–18 July 1997. Roraima state, rio Branco basin: MZUSP 56779 (4, 204.7– 227.9 mm SL) ; MZUSP 31447 (1, 234.1 mm SL): Caracaraí, rio Branco, cachoeira do Bem Querer , tributary 2 km above rapids, 1°58’N, 61°0’W; M.Goulding , Jan 1984. Pará state, rio Trombetas basin: MZUSP 5455 (1, 155.2 mm SL) ; MZUSP 58651 (1, 132.7 mm SL): Oriximiná, rio Trombetas , 1°45’S, 55°52’W; EPA , Dec 1967. MZUSP 56780 (1, 167.8 mm SL): rio Trombetas, Cuminá , c. 1°29’S, 56°1’W; M.Goulding , Oct–Nov 1983. INPA 5566 (1, 224.5 mm SL): rio Trombetas, Lago Abuí , 1°16’S, 56°57’W; E. Ferreira & J. Zuanon , 1 Sept 1990. Pará state, rio Amazonas basin: MPEG 14124 (1, 163.1 mm SL): Juruti, rio Amazonas, lago Jará , 2°9’19’’S, 56°4’6’’W; L.F . A. Montag, 1 Dec 2007. MPEG 13977 (2, 156.6–158.0 mm SL): Juruti, rio Juruti Grande , 2°22’55,1’’S, 56°18’51.6’’W; L.F . A. Montag, 27 Nov 2007. MZUSP 3574 (3, 127.5– 141.9 mm SL) : Santarém, rio Tapajós , c. 2°25’S, 54°45’W ; A. Amaral Campos , Oct 1944. MNHN 1909–070 (1, 115.1 mm SL): Santarém, “fleuve Amazone ”, c. 2°25’S, 54°45’W; C. Jobert, no date . MCZ uncat. (3, 255.0–295.0 mm SL): Pará, rio Tapajós [no precise locality]; N. Dexter & W. James, 26 Aug 1865 . Acre state, rio Juruá basin: ZUEC 6800 (1, 223.0 mm SL): Cruzeiro do Sul, mouth of rio Moá , 7°39’28’’S, 72°40’38’’W; G.V. Andrade , 2 June 1982. Peru, Depto. Loreto, rio Amazonas basin: MZUSP 15267 (3, 51.1– 67.0 mm SL): Santa Maria Hojeal , Río Amazonas; M.V. Correa , 26 May 1980. CAS 136581 (1, 82.3 mm SL); CAS 160517 (1, 88.7 mm SL); CAS 160753 (1, 118.2 mm SL); CAS 53426 (1, 92.0 mm SL); CAS 136580 (1, 89.2 mm SL); CAS 136579 (2, 127.3– 127.6 mm SL): Cano del Shansho, near Pebas , c. 3°21’S, 71°47’W; W.G. Scherer , 1936–1937. CAS 117266 (1, 95.3 mm SL); CAS 160574 (1, 90.0 mm SL): Rio Ampyiacu, near Pebas , c. 3°21’S, 71°47’W; W.G. Scherer , 1937–1940. MNRJ 4008 (1, 100.2 mm SL): near Pevas (= Pebas , c. 3°21’S, 71°47’W); W.G. Scherer, 1941 . USNM 175983 (2, 141.7– 156.3 mm SL): Tuye Caño, Río Ampyiacu drainage; W.G. Scherer , 17 Aug 1935. NRM 23399 (1, 107.3 mm SL): just below Esperanza village , mouth area of small quebrada tributary to Río Yaguasyacu , Río Ambyacu drainage, c. 3°21’S, 71°47’W; S.O. Kullander et al., 12 Aug 1981 . USNM 280505 (1, 110.8 mm SL): caño entering Río Manite 10 km upriver its mouth on Río Amazonas, 3°32’S, 72°40’W; R.P. Vari et al. , 21 Aug 1986. USNM 280051 (1, 126.2 mm SL): Río Nanay at Nanay beach, 3°50’S, 73°11’W; R.P. Vari et al. , 17 Aug 1986. MUSM 60 (2, 116.6– 129.3 mm SL): Iquitos, Río Nanay , Porto Almondras; H. Ortega & A. Urteaga, 6 Jul 1984. NRM 23668(1, 113.8 mm SL): Quebrada Corrientillo, 20 km from Iquitos on road to Puerto Almenda , c. 3°50’S, 73°13’W; S.O Kullander et al. , 18 Aug 1983. MUSM 1978 (6, 112.3– 117.7 mm SL): Iquitos, Quebrada Corrientillo, at Corrientillo , road Iquitos to Río Nanay, 3°49’57’’S, 73°21’43’’W; R.P. Vari et al. , 19 Aug 1986. INHS uncat. (1, 102.8 mm SL); INHS 44000 (4, 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. ANSP 136819 (3, 97.5–116.4 mm SL): Iquitos, Río Nanay just above Cocha Moronona (c. 9 miles above mouth at Río Amazonas); M. Holm , 17 Oct 1955. ANSP 178408 (1, 128.2 mm SL): Río Amazonas, sandy beach upstream mouth of Río Yanuyacu, 4°14’1’’S, 73°19’14’’W; M.H. Sabaj et al. , 11 Aug 2001. NRM 23397 (4, 104.3–107.0 mm SL): Varillal pool, Río Itaya drainage, c. 4°13’S, 73°29’W; S.O.Kullander et al. , 4 Jul 1986. NRM 23673 (1, 99.3 mm SL): Quebrada Pintoyacu, where crossed by carretera Iquitos-Nauta; S.O. Kullander et al., 3 July 1986. NRM 23398 (2, 95.6– 105.1 mm SL): pools near Quebrada Tocón Grande at km 33 on carretera Iquitos-Nauta , Río Itaya drainage, c.. 4°2’S, 73°26’W; S.O. Kullander et al. , 3 July 1986. MUSM 34 (1, 109.4 mm SL): Hucuyhuasi Shante, Iquitos; F. Benitez, 19 May 1975. MUSM 12744 (5, 109.2– 111.4 mm SL): Yanayacu, Base 3, Pluripetrol , Río Shiriyacu, 4°51’S, 74°56’W; H. Ortega , 10 Oct 1997. MUSM 18388 (2, 226.4– 226.9 mm SL): Río Paztaza, near mouth of Quebrada Asnagra , 3°17’23’’S, 76°23’3’’W; H. Ortega et al. , 5 Aug 1999. NRM 23395 (1, 114.7 mm SL): Base Tacsha , left bank sand playa of Río Samíria, c. 4°41’S, 74°20’W; S.O. Kullander et al. , 8 Aug 1986. CAS 69078 (ex IU 16021) (2, 143.8– 146.9 mm SL): Yarinococha (= Llarinococha ), shallow, clear cutoff lake connected to Rio Pacaya by a long, narrow channel, c. 5°9’S, 74°11’W; W.R. Allen , 1 Sept 1920. MUSM 18268 (1, 122.0 mm SL): Cocha San Pablo, Tipishca, Comunidade Sucre; H. Ortega et al. , 15 April 2001. MUSM 10892 (1, 86.8 mm SL): Río Chambira , Comunidad San Juan, c. 4°36’S, 74°52’W; E. Castro , 14 March 1997. MUSM 2660 (1, 117.3 mm SL): Iquitos, Tipishca del Río Samíria, c. 4°52’S, 74°22’W; C. Riofrio et al. , 23 Nov 1989. USNM 167787 (2, 145.0– 159.2 mm SL): mouth of Río Pacaya at Bretaña, c. 5°13’S, 74°18’W; W.R. Allen , Jul 1920. USNM 167789 (2, 125.9– 151.2 mm SL): Río Ucayali , Orellana, 6°55’S, 65°9’W; W.R. Allen, Aug 1920 . Depto. Ucayali: MZUSP 26644 (2, 128.1– 138.2 mm SL) : Ucayali, Pucallpa, Ivita (stocked from specimens collected at Iquitos); H.Ortega , 9 Sept 1976. MUSM 22 (3, 56.6–88.5 mm SL): same locality data as previous; H. Ortega , 28 Sept 1972. MUSM 3572 (1, 125.7 mm SL): Pucallpa, IVITA, Río Neshuya, Campo Verde; C. Rojas & G. Contreras , 24 Dec 1981. MUSM 53 (1, 159.3 mm SL): Pucallpa, Patria Nueva, Río Calleria near mouth of Río Ucayali, 8°31’S, 74°35’W; H. Ortega , 4 Oct 1984. AMNH 43314 (2, 61.1–62.8 mm SL); MUSM 2377 (2, 59.7–68.3 mm SL): Río Ucayali, Masisea , 8°35’S, 74°20’W; H. Ortega, 20–23 Nov 1973 . Depto. Pasco: USNM 167788 (1, 163.4 mm SL) : Río Pichis (trib. Río Pachítea), Puerto Bermudez , c. 10°18’S, 74°56’W; W.R. Allen, Jul 1920. USNM 167790 (2, 138.5– 187.2 mm SL) : Río Pachitea; W.R. Allen, Jul 1920. Depto . Madre de Dios: USNM 263993 (1, 269.9 mm SL): stream trib . Río Madre de Dios , 10 km below mouth of Río Tambopata, c. 12°30’S, 69°10’W; R.P. Vari et al., 25 Aug 1983. MUSM 9654 (1, 184.8 mm SL): Tambopata, Lago Valencia; C. Cañas , 19 June 1996. Peru, no precise locality: ANSP 21972 (3, 65.5–74.4 mm SL): “ Peruvian Amazon ”; J. Orton, no date . Ecuador: MEPN uncat. (1, 211.0 mm SL) : Pastaza , Río Lliquino, 2 km SE Villano , 01°24'S 77°40'W; R. Barriga & J. Llaney, 2 Sept 1997. MCZ 49158 (1, 242.7 mm SL) : Napo , Río Napo at Coca , 0°28’S, 76°56’W; T.R. Roberts, 28 Nov 1971 . FMNH 102253 (1, 243.0 mm SL): Napo , Río Lagartococha, 1km upstream its mouth at Río Aguarico, 0°38’S, 75°15’W; D.J. Stewart et al., 1 Nov 1983 . FMNH 102252 (1, 148.5 mm SL): Napo , Río Tiputini , near mouth at Río Napo, 0°49’S, 75°31’W; D.J. Stewart et al., 30 Oct 1981. FMNH 103394 (1, 293.0 mm SL) : Laguna Grande de Cuyabeno and Quebrada de Hormigas , Río Aguarico drainage, 0°0’30’’S, 76°11’30’’W; D.J. Stewart et al. , 28 Sept 1983. MEPN 10926 (1, 244.0 mm SL): Orellana, tributary of Río Tiputini , Pozo Zine; no collector/date specified . MEPN 11122 (1, 228.0 mm SL): Sucumbios , Río Napo at Garzacocha , 0°30’S, 76°22’W; no collector/date specified.

Figures

FIGURE 5. Diagrammatic representation of the patterns of dark colour markings found among cis-andean Brycon species, represented by selected species. A. Brycon stolzmanni. B. Brycon coxeyi. C. Brycon insignis. D. Brycon nattereri. E. Brycon hilarii. F. Brycon whitei. G. Brycon amazonicus. H. Brycon gouldingi. I. Brycon melanopterus. J-L. Brycon falcatus.

FIGURE 78. Brycon melanopterus, lectotype, ANSP 8035, 142.6 mm SL: Peru, Loreto, Río Ampyiacu. Photo by M. W. Littmann.

FIGURE 79. Brycon melanopterus, INPA 5566, 224.5 mm SL: Brazil, Pará, lago Abuí.

FIGURE 80. Brycon melanopterus, MZUSP 56948, 146.9 mm SL: Brazil, Amazonas, igarapé da Cachoeira.

FIGURE 81. Brycon melanopterus, NRM 23395, 114.7 mm SL: Peru, Loreto, Río Samiria.

FIGURE 82. Brycon melanopterus, MZUSP 15267, 67.0 mm SL: Peru, Loreto, Río Amazonas.

FIGURE 83. Map of northwestern South America, showing known localities of Brycon melanopterus (red dots).

Tables

TABLE 20. Morphometric data of Brycon melanopterus.

	n	Range	Mean
Standard length (SL)	91	95.6–289.1	-
Percentages of standard length
Depth at dorsal-fin origin	89	28.6–39.7	32.5
Snout to dorsal-fin origin	90	46.5–54.7	49.9
Dorsal-fin base length	91	10.3–15.2	12.2
Posterior terminus of dorsal fin to adipose fin	91	20.4–28.3	24.4
Posterior terminus of dorsal fin to hypural joint	91	31.0–41.9	36.0
Snout to pelvic-fin insertion	89	45.4–52.6	48.5
Snout to anal-fin origin	91	64.8–73.1	68.7
Anal-fin base length	91	17.5–24.0	22.2
Caudal peduncle length	91	10.9–18.4	15.1
Dorsal-fin height	90	15.9–25.6	21.4
Pectoral-fin length	90	15.6–21.7	19.0
Pelvic-fin length	87	13.9–21.7	16.5
Caudal peduncle depth	90	8.1–10.1	9.2
Head length	91	23.4–33.2	26.6
Percentages of head length
Head height	90	73.8–91.3	82.3
Snout length	91	26.1–38.5	31.9
Upper jaw length	91	42.5–49.0	46.1
Horizontal eye diameter	91	23.1–34.7	28.8
Post-orbital length	91	39.5–48.2	43.3
Least interorbital width	91	31.9–49.2	42.0