Brycon amazonicus ( Agassiz, 1829 )

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 : 112-129

Brycon amazonicus ( Agassiz, 1829)

( Figs. 66–73 )

Chalceus amazonicus Agassiz, in Spix & Agassiz, 1829: 68 –69, pl. 35 (Type locality: “in fluvio Amazonum”); Howes, 1982: 9 (comments).

Chalceus carpophaga Valenciennes, in Cuvier & Valenciennes, 1850: 252 –253 (Type locality: “l’ Esséquibo ” “l´ Amazone ”, retricted by Géry & Mahnert (1992: 816) to “ Essequibo ”). [not Kner, 1860: 12].

Chalceus hilarii (not Valenciennes): Kner, 1860: 10 –11 (part; “ Salto Theotonio”).

Megalobrycon cephalus Günther, 1869: 423 –424, fig. 1 (Type locality: “Upper Amazons”); Regan, 1905: 190 (Rio Negro; based on Wallace’s drawing).

Brycon capito Cope, 1872: 261 –262 (Type locality: “Ambyiacu”); Fowler, 1906: 446, fig. 42 (holotype, redescription).

Brycon longiceps Steindachner, 1879a: 150 (Type locality: “Orinoco bei Ciudad Bolívar”); Steindachner, 1879b: 157 –158, pl.1, fig.5 (full description); Mago-Leccia, 1970: 69 (listed, Venezuela; common name); Lasso, 1988: 127 (Lower Río Orinoco, Laguna los Barrancos; common name); Lima, 2003: 175 (primary type material; as a synonym of B. amazonicus ).

Brycon siebenthalae Eigenmann, 1912: 372 , pl. 54, fig. 3 (Type locality: “Mud Creek, Aruka River”); Géry, 1977: 338 (premaxillary teeth arrangement, holotype); Howes, 1982: 44 (comments); Cala, 1986: 91 (Río Ariari, Río Tomo; Río Guaviare; Río Vichada; western llanos of Colombia; common name; economic importance); Useche-L. et al., 1993: 341 – 348, 350–351 (Río Cafre, trib. Río Guaybero, Depto. Meta, Colombia; breeding; length/weight relationship; condition factor; gonadossomatic index; fecundity; feeding habits); Bernal-Ramírez & Cala, 1997: 55 –63 (Río Guayabero, Río Guaviare basin, Colombia: diet, seasonality); Lima, 2003: 175 (primary type material; as a synonym of B. amazonicus ).

Brycon pellegrini Holly, 1929: 208 –209 (Type locality: “Manaos”); Howes, 1982: 41 (possible synonym of Brycon cephalus ); Lima, 2003: 175 (primary type material; as a synonym of B. amazonicus ).

Chalceus taeniatus (not Jardine, in Jardine & Schomburgk): Magalhães, 1931: 130 (Amazonas; common name, natural history).

Brycon siebenthalae iquitensis Nakashima, 1941: 69 –70, fig. (Type locality: “cercanías del puerto de Iquitos”).

Brycon hilarii (not Valenciennes): Amaral-Campos, 1950: 140 (in part; “ Pará, rio Amazonas ”); Marlier, 1968: 56 (Paraná da Eva, central Amazon).

? Brycon stubelli (not Steindachner): Amaral Campos, 1950: 142 (rio Juruá, Amazonas).

Brycon sp.: Smith, 1979: 131 (Amazonas, Itacoatiara); Goulding, 1979: 95 –100, 133, 145–149 (Rio Machado, Rondônia; migrations, fisheries); Goulding, 1980: 68 –73 (Rio Machado, Rondônia; common name, diet, migrations); Crampton, 1999: 15, 27 (Reserva Mamirauá, lower rio Japurá, Amazonas); Barthem, 1999: 82, 94 (Central Amazon; fishery); Toledo- Piza, 2002: 122 –123 (drawing by A.R. Wallace; Yavita, rio Orinoco, Venezuela); Fernández et al., 2006: 58 (photo; upper Río Cataniapo, Rio Orinoco basin, estado Amazonas, Venezuela).

Brycon carpophagus: Howes, 1982: 15 –18 (in part; syntypes); Géry & Mahnert, 1992: 815 –817 (lectotype designation; Brycon siebenthalae as a synonym); Lima, 2003: 175 (primary type material; as a synonym of B. amazonicus ). [Not Mérona et al., 2001: 387, 391].

Brycon cephalus: Howes, 1982: 18 –20 (in part; Brazil, Manaus; Monte Alegre; “Manacapuni”); Zaniboni Filho et al., 1988: 41–50, fig. 7 (Brazil, rio Negro, rio Solimões, rio Japurá and rio Juruá; discussion); Zaniboni Filho & Resende, 1988: 833– 844 (gonad anatomy, maturity scale, type of spawning); Géry & Mahnert, 1992: 794 –800, 802, figs. 1 (lower), 5 (Central Amazon; diagnosis; common name; comparison with B. melanopterus ); Ferreira et al., 1998: 93, fig. 61 (Pará, rio Tapajós, Santarém; common name; fisheries); Pizango-Paima et al., 2001: 509 –520 (diet, seasonality, Central Amazon); Araújo- Lima & Ruffino, 2003: 253 –254 (migrations, fisheries; Amazon basin, Brazil); Diaz-Sarmiento & Alvarez-Léon, 2003: 311 (Amazon basin, Colombia; fisheries); Petry et al., 2003: 565, 575 (Ilha de Marchantaria, rio Solimões; occurrence related to macrophytes and other environmental gradients); Mérona & Rankin-de-Mérona, 2004: 77 (Lago do Rei, Ilha do Careiro, rio Amazonas; diet); Lima & Araújo-Lima, 2003: 788 –790, 792–793, 795, 797 (distribution of larvae and juveniles, central Amazon); Galvis et al., 2006: 188 –189 (Colombia, Rio Amazonas at Leticia; short description, drawing). [Not Galvis et al., 2006: 457, photo].

Brycon cf. melanopterum (not Cope): Braum, 1983a: 355 –371, fig. 1a (lip extension during hypoxia).

Brycon cf. melanopterus (not Cope): Braum, 1983b: 268 –269 (lip extension during hypoxia); Werder, 1983: 445 –461 (age estimates through circuli analysis); Junk et al., 1983: 408, 414, 426–427 (Lago Camaleão, Ilha da Marchantaria, rio Solimões; abundance, morphological adaptations to endure hypoxia); Werder & Soares, 1984: 398 –416 (Manaus; age determination thorugh circuli; scale variation); Piedade et al., 2006: 1176 (ingestion of Astrocaryum jauari fruits in the lower Rio Negro, Brazil).

Brycon melanopterus (not Cope): Bayley, 1988: 131 –133, 136 (in part; rio Solimões floodplains, Manaus area; growth rates of young specimens related to density and seasonality); Lasso, 1992: 11, 22, fig. 2 (río Suapure, Serranía de Los Pijiguaos, Rio Orinoco basin, Est. Bolivar, Venezuela).

Brycon cf. cephalus (not Günther): Goulding et al., 1988: 124 (Rio Negro); Ferreira, 1993: 56, 63, 86 (Pará, rio Trombetas basin: Oriximiná; igarapé Caxipacoré; rio Cachorro; rio Mapuera); Machado-Allison et al., 1999: 65 (Rio Caura, Estado Bolivar, Venezuela); Almeida-Toledo et al., 1996: 36, 39 (karyotype).

Brycon erythropterum (not Cope): Goulding et al., 1988: 124 (Rio Negro).

Brycon amazonicus : Lima, 2003: 175 (new combination; synonymic list, distribution, maximum length); Goulding et al., 2003: 138 (picture; rio Madre de Dios basin); Santos et al. 2006: 39 (retouched picture; description, biology, common name, fishery importance; Manaus area); Santos Filho & Batista, 2009: 195 –203 (growth, mortality rates; rio Madeira; rio Purus; Central Amazon); Lima & Ribeiro, 2011: 151, 161(“lowland” distributional pattern; influence of blackwater and tidal movements on distribution in Amazon basin); Lima et al., 2013: 228 –229 (Brazil, Rondônia, rio Madeira basin; distribution in the rio Madeira basin, short description, photo); Phillip et al., 2013: 8, 16 (Trinidad southern coast; occurrence as a vagrant species).

Brycon amazonicum: Leite, 2004: 661 –664 (Ilha da Marchantaria, rio Solimões, Amazonas; diet of juveniles). [Not Mérona et al., 2010: 106, 194]

Brycon bicolor (not Pellegrin): Fernández et al., 2006: 54 (photo; Río Cataniapo basin, Rio Orinoco basin, estado Amazonas, Venezuela).

Brycon cf. falcatus (not Müller & Troschel): Fernández et al., 2006: 55 (photo; upper Río Cataniapo, Rio Orinoco basin, estado Amazonas, Venezuela).

Diagnosis. Brycon amazonicus is distinguished from all its congeners, except B. falcatus , B. melanopterus , B. whitei , B. orbygnianus , B. orthotaenia , B. hilarii , and B. gouldingi by the possession of the fifth infraorbital bone higher than wide (vs. fifth infraorbital bone about as high as wide, or wider than high in the remaining species), and the presence of several narrow, longitudinal stripes along the dorsolateral surfaces of the body (vs. no narrow, longitudinal stripes along the dorsolateral surfaces of the body). It can be distinguished from B. falcatus and B. melanopterus by the possession of wavy longitudinal stripes along the dorsolateral surfaces of the body (vs. straight longitudinal stripes along the dorsolateral surfaces of the body), and darkened pectoral and pelvic fins (vs. pale pectoral and pelvic fins). Brycon amazonicus is distinguished from B. orbygnianus , B. hilarii , B. orthotaenia , and B. whitei by the lack of a broad, midlateral stripe along the caudal peduncle and middle caudal-fin rays (vs. presence of such a stripe), and darkened pectoral and pelvic fins (vs. pale pectoral and pelvic fins). The species most similar to Brycon amazonicus is B. gouldingi , from which it can be distinguished by the presence of dark pigment on the caudal peduncle and caudal fin diffuse, never crescent- or V-shaped (vs. a distinct crescent- or Vshaped blotch on the caudal peduncle and caudal fin). See the item “Comparisons”, below, for more details on the diagnosis between both species, as well as a discussion on the similarity in color pattern between Brycon amazonicus specimens from the Amazon basin in Peru with specimens of the partially sympatric B. hilarii .

Description. Morphometric data are presented in Table 18 . Large-sized species, largest examined specimen 485.0 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, 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. Eight (6), 9 (16), 10 (32), 11 (33), 12 (21), 13 (7), or 14 (1) relatively small tricuspidate teeth in outer series. Three (2), 4 (28), 5 (52), 6 (30), or 7 (1) tri- to pentacuspidate teeth in second, inner premaxillary row, plus 3 (15), 4 (84), 5 (13), or 6 (1) 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, medial teeth hexa- to heptacuspidate, symphyseal teeth penta- to hexacuspidate. Maxillary margins approximately parallel, straight in profile. Twelve to 24 maxillary teeth, slightly smaller than teeth of first premaxillary row, anterior teeth tricuspidate, posterior teeth unicuspidate. Dentary with 8 (11), 9 (13), 10 (16), 11 (4), 12 (5), 16 (1), or 19 (1) teeth in main series. Anterior four dentary teeth assymetrical, considerably larger and bulkier than remaining teeth, penta- to hexacuspidate, 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 11–16 small, aciculated, unicuspidate teeth, originating on lingual crest of dentary replacement trench at the level of fifth main series dentary teeth.

Scales cycloid. Lateral line complete, from supracleithrum to caudal-fin base. Fifty-seven (1), 61 (2), 62 (4), 63 (7), 64 (9), 65 (12), 66 (12), 67 (13), 68 (14), 69 (11), 70 (14), 71 (5), 72 (8), 73 (2), 74 (4), or 75 (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 (> 300 mm SL) specimens. Horizontal scale rows between dorsal-fin origin and lateral line 11 (12), 12 (18), 13 (56), 14 (30), or 15 (2). Horizontal scale rows between lateral line and pelvic-fin 5 (1), 6 (6), 7 (38), 8 (53), 9 (18), or 10 (1). Circumpeduncular scales 17(2), 18 (11), 19 (17), 20 (32), 21 (31), 22 (17), 23 (7), or 24 (1).

Dorsal-fin rays ii, 9. Dorsal fin origin slightly ahead middle of SL. First dorsal-fin pterygiophore inserting behind neural spine of 11th (1), 12 th (2), or 13 th (5) vertebrae. Anal-fin rays iii (not including first, small unbranched ray only visible in cs specimens), 20 (10), 21 (17), 22 (26), 23 (24), 24 (32), 25 (9), or 26 (1). First anal-fin pterygiophore inserting behind haemal spine of 24th (1), 25th (1), or 26th (3) vertebrae. 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 20–25 rectangular scales. Pectoral-fin rays i, 12 (5), 13 (29), 14 (71), or 15 (15). Pelvic-fin rays i, 6 (4), 7 (103), or 8 (13). Main caudal-fin rays 10/9. Caudal fin slightly forked, distal margin slightly concave. 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 13 (2), 15 (11), 16 (15), or 17 (2) lower, 1 at angle, and 13 (2), 14 (2), 15 (11), 16 (16), 17 (3), or 18 (1) upper gill rakers. Vertebrae 46 (1), 47 (1), or 48 (2). Supraneurals 8(3), 9(3), or 10 (2).

Coloration in alcohol. Top of head, snout, supraorbital, and sixth infraorbital light- to dark-brown. Dorsal portion of body light-brown 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 light brown, with a silvery hue. Humeral blotch present, conspicuous, approximately rounded in shape, situated immediately above lateral line, its anterior margin at level of second to third, extending longitudinally to posterior margin of sixth lateral line scales, and vertically one and half scales high. Dark, wavy longitudinal stripes formed by dark pigment concentrated on upper and lower scale margins extending along trunk moderately to highly conspicuous. Stripes more discernible dorsally. Series of irregular, narrow vertical stripes present in small (up to 80 mm SL) specimens. Diffuse dark pigmentation present at anal-fin basis, extending as a diffuse stripe into caudal-peduncle and upper caudal-fin lobe, forming an oblique stripe. Pigmentation on caudal peduncle and upper caudal-fin lobe generally less conspicuous and not forming an oblique stripe in specimens from the Río Orinoco basin, which possess instead a diffuse dark pigmentation on caudal fin. Juveniles (up to 80 mm SL) with a large, slightly assymetrical caudal peduncle extending into middle and upper caudal-fin rays basis, and anal-fin basis clear, without diffuse dark stripe. Most specimens from the upper Amazon basin in Peru (e.g., MZUSP 15266, MUSM 41154, MUSM 108, MUSM 315) with dark pigmentation concentrated on middle portion of caudal peduncle and middle caudal-fin rays. Pectoral and pelvic-fins generally dark in larger (> 150 mm SL) specimens. Lower caudal-fin rays, dorsal and anal-fins clear, with a variable amount of interradial dark pigmentantion. Adipose-fin light- to dark-grey.

Coloration in life. Based in pictures of fresh collected specimens from rio Guaporé (Rondônia), rio Sucunduri (Amazonas), lower rio Tapajós ( Ferreira et al., 1998: 93, fig. 61), rio Madre de Dios basin ( Goulding et al., 2003: 138), rio Gueppi (Loreto, Peru), and rio Solimões (Amazonas, Brazil). Overal color pattern light-grey, darker dorsally, with a silvery/plumbeous hue. Branchiostegal rays and lower half of opercle orangish in some specimens. Dark markings on anal and caudal fins and longitudinal wavy dark stripes generally very conspicuous, except in specimens collected in muddy/white waters, which generally present a drab overall coloration. All fins, but specially anal- and caudal-fins, pinkish.

Variation. There is relatively little geographical variation within Brycon amazonicus , except that, as discussed in the item “Coloration in alcohol”, most specimens from Peruvian Amazon present dark pigmentation concentrated on the middle portion of the caudal peduncle and caudal-fin, forming a dark stripe. These specimens are attributed to Brycon amazonicus due to their overall body shape and pectoral and pelvic fin dark coloration, and were often found in the same localities with the similar-looking B. hilarii (see the item “Comparisons”, below).

Common names. Brazil, Manaus: “matrinchã”, “ matrinchão ” ( Borges, 1986, Zaniboni et al., 1988; Santos et al., 2006: 39); rio Madeira basin, Rondônia: “jatuarana” ( Goulding, 1979, 1980). The same common names are applied, but with an inverse usage, to Brycon melanopterus on those same regions (see under “Common names” of B. melanopterus ). Venezuela: “palambra”, “bocón” ( Mago-Leccia, 1970: 69); “äi” (Piaroa language) ( Fernández et al., 2006: 54). Colombia: “yamú”, “bócon” ( Cala, 1986).

Distribution. Widespread in northern cis-andean South America, in the Rio Amazonas and Rio Orinoco basins ( Fig. 74 ). Brycon amazonicus is a typical lowland, muddy-water species. Its distribution in the Amazon basin encompasses the middle and upper section of the Rio Amazonas /Solimões, from Pucallpa (8°23’S, 74°31’W) at the Río Ucayali in Peru eastward to Porto de Moz at the lower rio Xingu (1°45’S, 52°14’W) in Brazil, and the rio Madeira up to its upstream reaches at Bolivia and Brazil. The species occurs in clear-water rivers as the rio Tapajós and rio Xingu only at their lower sections, below the major rapids. At the rio Negro, the species is also confined to its lower section, migrating dowstream into the rio Amazonas /Solimões to spawn ( Borges, 1986). At the Rio Orinoco basin, Brycon amazonicus is widespread at the middle/lower sections in both muddy- and clear-water tributaries. Brycon amazonicus is known from the northwestern portion of Guyana, near the border with Venezuela, at the Amacuro River drainage, a river system connected with the Orinoco delta. The species is recorded from the island of Trinidad, an odd occurrence which is discussed at the “Biogeography” section. As some other highlyfecund, total spawners characiforms as Colossoma macropomum (Serrasalmidae) , Brycon amazonicus is only rarely found in the lower Amazon, apparently because the circadian variations of water level due to tidal influence does not allow the establishment of a population of the species in that river stretch ( Lima & Ribeiro, 2011: 161). Brycon amazonicus has been extensively stocked, and escaped individuals are recorded from several river drainages in southeastern and central Brazil, but so far there is no evidence of self-sustaining, established populations outside its native range. These records are not mapped in Fig. 74 .

Comparisons. Brycon amazonicus is overall more similar, and possibly closely related to B. gouldingi . Besides the caudal-fin color pattern, there are two additional differences between the species. One, the presence of a straight, well-defined dark stripe on the anal-fin base in B. gouldingi (vs. a diffuse dark stripe on the anal-fin base in B. amazonicus ), cannot, however, be used to unequivocally distinguish both species because a dark stripe is often absent in B. gouldingi specimens larger than 200 mm SL and in some specimens of B. amazonicus of all sizes. The second distinguishing character is lateral line counts, which present a large overlap, but are generally lower in Brycon amazonicus (vs. 57–75, modally 68 in B. amazonicus , vs. 66–82, modally 74, in B. gouldingi ).

There is a striking resemblance between specimens of Brycon amazonicus and B. hilarii from the Peruvian portion of the Amazon basin (from Iquitos, Depto. Loreto, upriver to Pucallpa, Depto. Ucayali). Most specimens of Brycon amazonicus from this portion of the basin possess a color pattern reminiscent of B. hilarii , with dark pigmentantion concentrated on the middle/distal portion of the caudal peduncle and middle caudal-fin rays (see item “Variation”, above). Though the majority of the specimens of Brycon amazonicus from the Peruvian portion of the Amazon basin present this color pattern, a few specimens from the area near Iquitos display the “typical” color pattern (e.g., ANSP 178374, MUSM 7020). Brycon amazonicus from the Peruvian portion of the Amazon basin are not easily distinguished from the sympatric B. hilarii , though the latter are typically more slender fish, with less angled predorsal and pre-pelvic body profiles, with clear-colored pectoral and pelvic fins (pectoral and pelvic fins typically darkened in B. amazonicus ), and with a more developed caudal peduncle/caudal fin stripe (which in B. amazonicus is more blotch-like). Both species are sympatric and often collected together along the Río Amazonas and Río Ucayali from Iquitos to Pucallpa. There are no records of Brycon hilarii downstream from the Iquitos area, and no records of Brycon amazonicus upstream from the Pucallpa area. See the discussion under the item “Putative examples of mimicry involving Brycon ”, below.

Ecological notes. Detailed information on the ecology of Brycon amazonicus were provided by Goulding (1979, 1980; as Brycon sp.), and Borges (1986; as Brycon cf. erythropterum ). Goulding (1979, 1980) studied the species at the rio Machado (rio Madeira basin, Rondônia). Goulding (1980) considered Brycon amazonicus as a primarily seed/fruit eater during the flood season. Most importantat seed/fruits species found in guts of Brycon amazonicus specimens caught in the flooded forest of the rio Machado were Hevea spruceana (Euphorbiaceae) , Hevea brasiliensis (Euphorbiaceae) , Luffa sp. (Curcubitaceae), Neobalatia sp. ( Sapotaceae ), and Calyptranthes ruizana (Myrtaceae) ( Goulding, 1980). Also found were terrestrial arthropods, leaves and rodent remains. Specimens caught during the dry season generally possessed empty guts ( Goulding, 1979, 1980). Complex migratory patterns are reported between the rio Madeira and clearwater tributaries, which can be summarized as a migration into the flooded forests during the early flood season, a downstream spawning migration from the clearwater tributaries into the muddy-water rio Madeira during the middle of the flood season, return to the flooded forests after the spawning, and a massive dispersive migratory movement in the early dry season, when the schools of Brycon amazonicus may contain hundreds to thousands of individuals ( Goulding, 1979).

Borges (1986) studied diet and migrations of the species in rio Negro. Adult specimens (260–455 mm SL) presented a mean stomach fulness higher during the flood season. Fruits, seeds and arthropods were the main dietary itens, with fruits and seeds more common during the flood season and arthropods more expressive during the dry season. Among the fruits/seeds, Euphorbiaceae ( Hevea spruceana , Mabea caudata , and Alchornea schomburgkiana ) were dominant in guts contents, followed by Lauraceae , “Leguminosae”, Arecaceae , Moraceae , Melastomataceae , and Annonaceae ( Pseudoxandra polypheba ). Borges (1986: 50–51) noticed that the fruit/seed species that dominated in the diet were generally found crushed in stomach contents, while species presenting a relative smaller importance were generally found intact. Fishes and reptiles (lizards and snakes) were also found in low frequences in gut contents. Juvenile specimens (smaller than 185 mm SL) ingested a considerably larger proportion of arthropods and fishes when compared with adult specimens. Similarly to the observations of Goulding (1979, 1980), specimens collected in migratory schools or terra firme streams during the dry season generally possessed empty stomachs. Borges (1986: 123–125) summarized the available natural history information on Brycon amazonicus at the rio Negro basin. This author hypothesized that Brycon amazonicus does not spawn in this river system, since juvenile specimens are never collected in the area (nor larvae; Lima & Araújo- Lima, 2004), but are very common in the floodplains lakes of the rio Solimões/ Amazonas. Also, downstream migrations are observed in the rio Negro during the flood season (December/January), implying that in fact the species spawn in the rio Solimões/ Amazonas. A few other characiform fishes that possess similar migratory/ spawning habits are Colossoma macropomum , Semaprochilodus taeniurus , and S. insignis ( Ribeiro & Petrere, 1990; Araújo-Lima & Goulding, 1997; Goulding et al., 1988), and in fact Brycon amazonicus was reported to be associated with both Semaprochilodus species in multi-species schools during its downstream migration ( Araújo & Ruffino, 2003), though most often they migrate in their own monospecific schools (M.C.L. Ribeiro, pers. comm..). This type of migratory behavior probably evolved as a response to the extreme oligotrophic water of the rio Negro basin, which does not allow an effective recruitment of larvae and juveniles of these highly-fecund species ( Borges, 1986; Araújo-Lima & Ruffino, 2003; Lima & Araújo-Lima, 2004). Interestingly, all the aforementioned species, as well as Brycon amazonicus , only occur in the lower section of the rio Negro basin (see Araújo-Lima & Goulding, 1997; Castro & Vari, 2004). Similarly to the findings of Goulding (1979, 1980) in the rio Madeira basin, Borges (1986) noticed that Brycon amazonicus return to the flooded forests of the lower rio Negro after spawning in February and March, primarily to eat seeds and fruits, and leave them for the terra firme large streams or the channel of the nearby muddy/whitewater river system (in that case, the rio Solimões/ Amazonas) during the the beginning of low water season (May to August) ( Borges, 1986; Araújo-Lima & Ruffino, 2003). Though in fact juvenile specimens of Brycon amazonicus are abundant in the floodplains of the rio Solimões/ Amazonas (e.g., Bayley, 1988, as B. melanopterus ; Petry et al., 2003, as B. cephalus ), contrary to the view by Borges (1986) and Lima & Araújo-Lima (2004), they are not completely absent from the rio Negro, since a few lots of juveniles have been located in collections (INPA 11072, MZUSP 60311, USNM 307069), indicating that a limited recruitment may occur at this system as well. Zaniboni Filho & Resende (1988, as B. cephalus ) analysed with light microscopy the gonadal development in the species using specimens collected in the lower rio Negro and middle rio Solimões/ Amazonas and concluded that the species is, as expected, a total spawner, and that specimens smaller than 160 mm SL cannot be identified to sex by a macrocospic examination of gonads. Females are estimated to reach maturity at 3 years of age and 28 cm SL ( Arias, 2006). The species is reported to reach 50 cm TL in the rio Madeira basin ( Goulding, 1980: 68), and the largest specimen examined by Santos Filho & Batista (2009) during their broad survey of Brycon amazonicus specimens landed at the Manaus market measured 52 cm TL. Brycon amazonicus is well-known for the hability in developing a transitory dermal lip protuberance during periods of hypoxia ( Braum, 1983a, b; as Brycon cf. melanopterum ), an adaptation in fact shared with some other characids (Winemiller, 1989b). An increase in number of maxillary teeth and gill rakers is reported to occur during the ontogeny of the species (Zaniboni Filho & Resende, 1988).

The species presents a great importance in fisheries across its entire range (see Barthem, 1999; Araújo-Lima & Ruffino, 2003; Santos et al., 2006) and has been one of most aquacultured fish species both in Brazil (e.g., Werder & Saint-Paul, 1979; Mendonça, 1994) and Colombia ( Arias, 2006).

Remarks. Chalceus amazonicus was described by Agassiz (in Spix & Agassiz, 1829: 68–69) for the “fluvio Amazonum” (= rio Amazonas, Brazil). The species is named as Characinus amazonicus at its depiction (plate 35), which is supposedly how Spix intended to name it, since he only supervised the execution of the plates ( Kottelat, 1988). The genus Characinus was never described, and consequently constitutes a nomen nudum. Chalceus amazonicus was considered in the literature as a synonym of Brycon opalinus by Valenciennes (in Cuvier & Valenciennnes, 1850), and that practice was followed subsequently ( Günther, 1864; Eigenmann, 1910; Fowler, 1950), until Howes (1982: 9) removed it from that synonymy. Howes (1982: 9) considered that the description of Chalceus amazonicus by Agassiz (in Spix & Agassiz, 1829) was very similar to the syntypes of C.carpophagus , but he preferred to consider the name as a nomen dubium due the precariousness of the original description. Howes (1982: 9) erroneously inferred that the species was based on an iconotype, when actually the holotype was deposited at Munich (“In the Museum at Munich there is a fine specimen, 10 inches long, preserved in spirits of wine”; translation of the original description by Pethiyagoda & Kottelat, 1998: 155). Kottelat (1988) was not able to find the holotype of Chalceus amazonicus among the material that Agassiz moved to the Musée d’Histoire Naturelle de Neuchâtel, and inferred that as most of Spix’s Brazilian material, it was very likely destroyed during the British bombing of the Bayerische Akademie der Wissenschaften during the night of 24–25 April 1944.

The original description of Chalceus amazonicus only provides very general information on the species, which does not allow a clear association of the name to any of the known Brycon species from the Amazon basin. The illustration of the holotype shows a relatively elongated fish, with an olivaceous dorsal coloration, a brown body and a grayish head. Counts of the illustrated holotype are 62 lateral-line scales, 9 scales rows between dorsal-fin origin and lateral-line, 7 horizontal scales between the lateral line and the pelvic-fin insertion, and 17 branched anal-fin rays. However, as noticed by Howes (1982: 9), there is a discrepancy between the number of anal-fin rays in the illustration and the number given in the description (iii, 24). The rather vague type-locality “fluvio Amazonum” indicate that the type-specimen may have been collected across a vast expanse of the Amazon basin. The expedition leaded by J. B. Spix and C. F. Martius crossed the whole extension of the rio Amazonas /Solimões in Brazil and moved upstream into the lower course of some of its tributaries, namely, the rio Negro, rio Tapajós, rio Madeira, and rio Japurá ( Papavero, 1971: map 7). However, in the diary of the expedition, Spix & Martius (1981: 96) reported that Chalceus amazonicus was collected at the rio Amazonas, a little above the canal de Uruará, which is situated slightly below Monte Alegre, Pará state. It is therefore assumed that the lower Amazon should be considered the area of provenance of the holotype of Chalceus amazonicus . Two Brycon species are commonly found in the lower rio Amazonas channel and floodplains. One of them is Brycon melanopterus , a species diagnosed by the presence of a conspicuous oblique dark stripe extending from pelvic-fin basis to the upper lobe of caudal fin (see under this species, below). As remarked above, the plate of Chalceus amazonicus in Spix & Agassiz (1829) shows a specimen with a uniform color pattern, without blotches or stripes. The description by Agassiz is also uninformative in regard to any dark pigmentary feature that might eventually be present in the specimen (“head bluish, but the rest of the entire fish is olive grey and bright gold”; Pethiyagoda & Kottelat, 1998). Since the oblique stripe in Brycon melanopterus is conspicuous even in highly-faded specimens, it seems unlikely that Chalceus amazonicus corresponds to this species. It is more likely that Chalceus amazonicus refers to a species described subsequently several times under different names, beginning with Valenciennes (in Cuvier & Valenciennes, 1850) as Chalceus carpophaga . Since the holotype of Chalceus amazonicus was lost, a neotype need to be designated in order to dispel any doubt concerning the identity of the species. Therefore, we herein designate the specimen INPA 3415, collected in the rio Trombetas, a tributary of the Rio Amazonas at Pará state, a locality relatively close to Monte Alegre, as the neotype of Chalceus amazonicus Agassiz.

Brycon amazonicus , as herein recognized, comprises seven synonyms. Valenciennes (in Cuvier & Valenciennes, 1850: 252–253) described Chalceus carpophaga from the “Essequibo” and “Amazone”. In spite of the fact that Valenciennes have not selected a holotype for the species, the description of the species is clearly based on a specimen said as have being collected at the Essequibo River by Schomburgk. Bertin (1948: 15) reported three syntypes for the species: MNHN A.9832 (“Fl. Essequibo”), MNHN 98 (Amazon River), and MNHN A.8615 (Sabará, Minas Gerais). Géry & Mahnert (1992: 816) appropriately designated the specimen MNHN A.9832 as the lectotype of the species, and noticed that while the paralectotype MNHN 98 is possibly conspecific to the lectotype, the paralectotype MNHN A.8615 is probably a specimen of Brycon orthotaenia , a supposition confirmed in the present study (see item “Remarks” of B. orthotaenia ). The lectotype of Chalceus carpophaga is rather faded, but longitudinal wavy stripes can still be recognized in the specimen. This is a feature shared by some Brycon species, among them, B. amazonicus , which is the only species presenting this pigmentary feature known to occur in northeastern South America. Morphometric and meristic data are within the range of variation observed in Brycon amazonicus . Chalceus carpophaga is therefore considered as a junior synonym of Brycon amazonicus . Though Valenciennes (in Cuvier & Valenciennes, 1850) mentions “Essequibo” as the locality for the lectotype of Chalceus carpophaga , the label of the specimen records its locality as being merely “Guyane Anglaise”. Just a few more specimens of Brycon amazonicus are known from Guyana (AMNH 14405 and FMNH 53353, the latter being the holotype of B. siebenthalae , see below), all of which were collected in the Amacuro River system in northwestern Guyana (see item “Distribution”, above). Since no additional specimen of Brycon amazonicus has ever been collected in the Essequibo River itself, we strongly suspect that the locality of the lectotype of Chalceus carpophaga given by Valenciennes (in Cuvier & Valenciennes, 1850) is incorrect, though as a Schomburgk specimen, it was in fact very likely collected somewhere else in Guyana, more likely at the Amacuro river system (see below).

Günther (1869: 423–424) described Megalobrycon cephalus based on two specimens (BMNH 1869.5.21: 1–2) collected by Edward Bartlett at the “Upper Amazons”. Judging for another collections by Bartlett sent to the British Museum, these specimens were likely collected in the peruvian portion of the Amazon basin (e.g., Günther, 1868: 229; Sclater & Salvin, 1866). Günther (1869) did not compared Megalobrycon cephalus to any Brycon species, remarking only at the generic diagnosis that Megalobrycon would be “closely allied to Bryconops ” (see comments on the item “Remarks” of the generic section, above). Both syntypes are now in a very poor state of preservation, with almost no scales left on the body, fins broken, and cranial bones in process of disarticulation. In fact, these specimens were already reported to be in a poor state of preservation when first studied ( Günther, 1869). The best preserved syntype possess wavy longitudinal stripes in the scales of the upper portion of the caudal peduncle (the only portion of body with a large number of scales still present) and about 58 lateral-line scales (counts obtained through counting scale pockets). These two features combined suggests that the syntypes of Brycon cephalus refer to B. amazonicus , since the other Brycon species with wavy longitudinal stripes known to occur in the upper Amazon basin in Peru, B. hilarii , possess considerably higher lateral-line scales counts (67–82). We thus consider Brycon cephalus as a synonym of B. amazonicus . Brycon cephalus was until the recent past the name usually employed for B. amazonicus in the Central Amazon basin (e.g., Regan, 1905; Howes, 1982; Zaniboni Filho & Resende, 1988; Géry & Mahnert, 1992; Ferreira et al., 1998; Araújo-Lima & Ruffino, 2003). Howes (1982), Zaniboni Filho & Resende (1988), and particularly Géry & Mahnert (1992) studied in detail the variation and diagnostic features of Brycon amazonicus , under the name B. cephalus , comparing it with the syntopic B. melanopterus .

Cope (1872: 261–262) described Brycon capito from “Ambyiacu” (= Río Ampyiacu, near Pebas, Loreto, Peru), the same type-locality of Megalobrycon erythropterum (a synonym of B. hilarii , see item “Remarks” of the latter species). Cope (1872) did not compared Brycon capito with any other Brycon species, nor discussed why he considered it to be a new species. The holotype of Brycon capito (ANSP 8058) was examined during the course of the present study, and is a juvenile Brycon specimen in very poor condition of preservation, being desiccated, scaleless, and faded ( Fig. 68 ). Lateral-line counts of the holotype of Brycon capito were low, according to Cope (1872) (56 lateral line scales), a count considerably lower than counts of the sympatric B. hilarii (67–82) but very close to the range of B. amazonicus (57–75). The holotype of Brycon capito does not seem to be distinct from B. amazonicus juveniles (compare Figs. 70 and 75 ), and thus, we consider the earlier as a synonym of the latter.

Steindachner (1879a: 150) briefly described Brycon longiceps , without mentioning its type-locality. A little later, a proper description of the species was published ( Steindachner, 1879b: 156–157). Steindachner (1879b) described the species based on three juvenile specimens (NMW 62944: 1–3), collected in the Río Orinoco at Ciudad Bolívar, Venezuela. The examination of the three syntypes revealed them to represent juveniles of Brycon amazonicus . Interestingly, Steindachner (1879b) suggested that the species was in fact more similar to Brycon carpophagus (= B. amazonicus ), and that he was precluded of doing an adequate comparison between both species because the type series of B. longiceps consisted in juvenile specimens, while B. carpophagus was solely known from a few large and poorly preserved specimens.

Eigenmann (1912: 372) described Brycon siebenthalae from a single specimen collected at “Mud Creek, Aruka River”, an independent coastal drainage from northwestern Guyana, near the border with Venezuela. We examined the holotype of the species and concluded it to be a synonym of Brycon amazonicus , a conclusion actually earlier advanced by Géry & Mahnert (1992: 816:“présente tous le caractères de B. carpophagus … il s’agit très probablement d’un synonym”). As remarked above, there are few Brycon amazonicus specimens reported from Guyana, and the species appears to be restricted in that country to the northwestern river basins, which are connected to the Orinoco delta via the Amacuro River (see item “Distribution”, above).

Holly (1929: 208–209) described Brycon pellegrini from Manaus, in the lower rio Negro /central Amazon area, Brazil. Holly (1929) does not compared the species to any congener, only mentioning that it was probably related to Brycon moorei . Both Howes (1982: 41) and Géry & Mahnert (1992: 797) considered this species to be a junior synonym of B. cephalus (= Brycon amazonicus ). The holotype of Brycon pellegrini was not examined during the present study, but its original description provides enough information to allow a safe judgement concerning its taxonomic status. At the Manaus area, four Brycon are known: B. pesu , B. falcatus , B. melanopterus , and B. amazonicus . Holly (1929) mentions that the holotype of Brycon pellegrini possess the caudal-fin basis darkened (“Schwanzflossenbasis ist dunkler”). The only Brycon species occurring in the Manaus area to conform such a description of the caudal-fin basis is B. amazonicus , since the remaining species either lack dark pigmentation at the basis of caudal fin ( B. pesu ) or possess a very characteristic caudal-basis color pattern that would not be so succinctly described if present ( B. falcatus and B. melanopterus ). In addition, the stated scale counts for the holotype of Brycon pellegrini , 69/14/9 ( Holly, 1929) are beyond the upper limits known for B. falcatus and B. pesu , but within the range of both B. melanopterus and B. amazonicus . Finally, Holly (1929: 209) mentions that the fins are brownish (“Die flosse sind braun”). Darkened paired fins are found, among the Brycon species present in the Manaus area, only in B. amazonicus . Consequently, and confirming the view advanced by Howes (1982) and Géry & Mahnert (1992), there is enough evidence to consider Brycon pellegrini as a synonym of B. amazonicus .

Brycon siebenthalae iquitensis Nakashima (1941: 69–70) was described having as its type-locality “las cercanías del puerto de Iquitos”. The type material was apparently never deposited in a fish collection and is lost (H. Ortega, pers. com.). Nakashima (1941) did not provided any reasoning about why to describe a subspecies of Brycon siebenthalae from the Amazonian portion of Peru. Presumably, he merely gave a subspecific status to a Brycon population he considered to be conspecific with Brycon siebenthalae from Guyana. Though the inaccurate description given by Nakashima (1941), compounded with the lack of type-material precludes a definitive conclusion, we consider that the best alternative available to merely consider Brycon siebenthalae iquitensis as a synonym of B. amazonicus .

Both Kner (1860) and Amaral-Campos (1950: 140) mixed in their accounts of Brycon hilarii specimens authentically belonging to the latter species (from “Cujaba” and “ Mato Grosso ”, respectively) with specimens of B. amazonicus , probably because of the high scales counts shared by both species. Kner (1860: 11) cites a specimen collected by J. Natterer at “ Salto Theotonio” (now spelled Salto Teotônio, at the rio Madeira, Rondônia, Brazil), under the common name “Schatö-arana”, an obvious mispelling of “jatuarana”, the common name by which Brycon amazonicus is still known in the rio Madeira basin.

Braum (1983a, b) studied the ability of a Brycon species from central Amazon in developing oral dermal protuberances to withstand hypoxia. Although he identified the species he studied as Brycon cf. melanopterus , a picture published in one of the articles ( Braum, 1983a: fig. 1a) shows that, instead, that he has studied B. amazonicus . Lasso (1992: 11) identified Brycon melanopterus from the lower río Suapure, Río Orinoco basin. The picture presented in the paper (fig. 3, p. 22) shows, instead, a specimen of Brycon amazonicus . Brycon melanopterus is in fact restricted to the Amazon basin (see item “Distribution” and “Comparisons” of this latter species). Bayley (1988) studied the growth of several young fish species occurring in the floodplains of rio Solimões near Manaus, including what that author has identified as Brycon melanopterus . Examination of the material collected by Bayley in both USNM and MZUSP collections showed that, although there are in fact a few Brycon melanopterus specimens in his Brycon samples, the bulk of it is actually constituted by B. amazonicus . Another possible misidentifications involving the species (e.g., Brycon cf. melanopterus ; Junk et al., 1983; Brycon hilarii ; Marlier, 1968: 56) could not be checked due to lack of information on the material which based them, but are with great likelihood attributable to B. amazonicus .

Galvis et al. (2006: 188–189) identified Brycon cephalus (= B. amazonicus ) from Leticia, Colombia. Though the characters used in their description allow the identification of the material examined by them as Brycon amazonicus (e.g., the pigmentary features of the scales; Galvis et al., 2006: 189, fig. 85d), the picture of the species (p. 457) depicts instead a specimen of B. melanopterus .

Material examined. Type material: INPA 3415 (1, 362.0 mm SL): Brazil, Pará, rio Trombetas, igarapé Caxipacoré , c. 0°34’S, 56°45’W; E. Ferreira & M. Jégu, 20 April 1985 . Neotype of Chalceus amazonicus Agassiz, in Spix & Agassiz, 1829 , by present designation. MNHN A.9832 (1, 267.8 mm SL): “ Guyane Anglaise”; Schomburgk , no date . Lectotype of Chalceus carpophaga Valenciennes (designated by Géry & Mahnert, 1992: 816). MNHN 98 (1, 260.9 mm SL): “ Amazone ”; Montravel , no date . Paralectotype of Chalceus carpophaga Valenciennes (designated by Géry & Mahnert, 1992: 816). BMNH 1869.5.21: 1 (2, 235.7–307.0 mm SL): “ Upper Amazons ”; E. Bartlett, no date ; syntypes of Megalobrycon cephalus Günther. ANSP 8058 (1, 46.0 mm SL): “ Ecuador, Ambyiacu River ” [= Peru, Depto. Loreto, Rio Ampyiacu, trib. Río Amazonas , c. 3°21’S, 71°48’W]; J. Hauxwell, no date . Holotype of Brycon capito Cope. NMW 62944 (49.1–67.7 mm SL): “ Orinoco bei Ciudad Bolivar ” [ Venezuela, Estado Bolivar, 8°8’N, 63°34’W] ; Schilling, 1879; syntypes of Brycon longiceps Steindachner. FMNH 53353 (1, 169.1 mm SL): Guyana, Mud Creek in Aruka River [c. 8°13’N, 59°44’W]; S.E. Shideler, 1908 . Holotype of Brycon siebenthalae Eigenmann.

Non types. Brazil, Pará state, rio Amazonas basin: MCZ 21134 (1, 174.7 mm SL) ; MCZ 21089 (3, 161.4– 174.0 mm SL): Rio Xingu , Porto de Moz, 1°45’S, 52°14’W; Thayer Expedition, Aug–Sept 1865 . BMNH 1926.10 .27.7 (1, 190.4 mm SL): Monte Alegre , Rio Amazonas, 2°0’S, 54°4’W; C. Ternetz, no date . MZUSP 9501 (1, 121.6 mm SL): Monte Alegre , rio Amazonas, 2°0’S, 54°4’W; EPA, 14 Aug 1968 . MNRJ 11263 (1, 200.8 mm SL): rio Amazonas, “ Maicura ” (probably rio Maicuru , c. 2°9’S, 54°12’W); L. Travassos & J. de Freitas, Feb 1960 . MZUSP 9177 (1, 185.0 mm SL): Santarém, rio Maicá , c. 2°27’S, 54°40’W; EPA, 19–27 Oct 1971 . CAS 68830 (1, 159.0 mm SL): “ Lagoa Grande into Rio Amazona at Castello Branco ” (probably Lagoa Grande de Curuaí , c. 2°14’S, 55°16’W); C. Ternetz, 14 Jul 1923 . CAS 68884 (1, 174.7 mm SL): “ Lagoa Grande into Rio Amazon” (probably Lagoa Grande de Curuaí , c. 2°14’S, 55°16’W); C. Ternetz, Nov 1924 . ZUEC 8033 (1, 223.0 mm SL), Curuá, Lago Preto, fazenda São Luís (Costa do Cruzeiro, rio Amazonas), 2°6'22''S, 55° 10'17''W; F.C. T . Lima, W.G.R. Crampton, J.S. Ready et al., 22 Nov 2013. MCZ 21099 (2, 139.2– 170.7 mm SL) ; MCZ 21098 (1, 155.7 mm SL): Rio Amazonas, Óbidos , 1°52’S, 55°30’W; Thayer Expedition, Nov–Dec 1865 . MPEG 11181 (1, 190.6 mm SL): Juruti, Igarapé Guaraná , 2°29’19’’S, 56°14’19’’ W; A. Hercos & V. Sena, 21 Aug 2006 . CAS 66852 (1, 94.3 mm SL): Juruti , 2°9’S, 56°6’W; no collector specified . ANSP 82285 (1, 207.0 mm SL): “ Para ”; J.L. Troemner, no date . Pará state, rio Tapajós basin: MZUSP 8405 (3, 146.6– 156.6 mm SL) : Santarém, igarapé Jacundá, Alter do Chão , c. 2°30’S, 54°58’W; EPA, 23 Dec 1967 . MZUSP 57475 (1, 258.1 mm SL): Santarém, Alter do Chão , 2°28'5''S 54°55'34''W; M. Westneat et al., 31 Oct 1994 . MZUSP 60323 (1, 154.5 mm SL): Santarém, rio Tapajós , 2°25’S, 54°45’W ; A. Campos, Oct 1944. FMNH 92083 (1, 159.6 mm SL) : Santarém, rio Tapajós , 2°25’S, 54°45’W; J.D. Haseman, 12 Dec 1909. MCZ 20780 (1, 117.7 mm SL) ; MCZ 21094 (1, 176.3 mm SL): Santarém, rio Tapajós , 2°25’S, 54°45’W; D. Bourget, 1865 . MCZ 21125 (3, 258.0–315.0 mm SL): Rio Tapajós, probably at its mouth; N. Dexter et al., 26 Aug 1865 . CAS 68858 (1, 150.2 mm SL); CAS 68854 (1, 128.4 mm SL): market at Santarém; C. Ternetz, Aug–Sept 1924 . CAS 68837 (1, 243 mm SL); CAS 68915 (3, 115.7– 121.3 mm SL): rio Tapajós , Santarém, 2°25’S, 54°45’W; C. Ternetz, July 1924 . MNHN 1909-070 (1, 115.1 mm SL): Santarém, 2°25’S, 54°45’W; C. Jobert, no date . Pará state, rio Trombetas basin: MZUSP 8255 (1, 151.0 mm SL): rio Trombetas, Oriximiná , 1°47’S, 55°52’W; EPA, 16–18 Dec 1967 . MZUSP 56777 (3, 207.2– 231.6 mm SL): rio Trombetas, Cuminá , c. 1°31’S, 56°2’W; M. Goulding, Oct–Nov 1983 . INPA 16449 (1, 341.3 mm SL): rio Cachorro (trib. rio Trombetas ), c. 1°0’S, 57°3’W; E. Ferreira & L.H.R. Py-Daniel, 18 Oct 1985 . INPA 16440 (1, 364.1 mm SL): rio Trombetas, near the mouth of igarapé Caxipacoré , c. 0°35’S, 56°47’W; E. Ferreira & L.H.R. Py-Daniel, 16 Oct 1985 . INPA 3416 (1, 317.6 mm SL): rio Mapuera (trib. rio Trombetas), Cachoeira da Égua , c. 1°5’S, 57°20’W; E. Ferreira, 17 May 1985 . Amazonas state, rio Solimões / Amazonas basin: MZUSP 5801 (2, 317.2– 329.7 mm SL): Lago Saracá, Silves , c. 2°53’S, 58°21’W; EPA, 17–18 March 1967 . MCZ 21124 (1, 176.5 mm SL): Lago Saracá at Silves , c. 2°53’S, 58°21’W; S.V.R. Thayer, Dec 1865 . MCZ 21086 (2, 147.0– 183.2 mm SL): Rio Amazonas, Parintins , 2°38’S, 56°45’W; L. Agassiz, 27 Aug–2 Sept 1865 . MCZ 21091 (1, 160.4 mm SL): Lago José Assú [= Igarapé Açu or rio Andirá , 2°54’S, 57°8’W]; L. Agassiz, 27–30 Aug 1865 . MZUSP 13430 (1, 323.2 mm SL): Itacoatiara , rio Amazonas, 3°9’S, 58°27’W; N. Smith, 28 Sept 1977 . MNHN 1996-1085 (1, 184. mm SL); MNHN 1996-1089 (1, 191.8 mm SL); MNHN 1996-1081 (1, 291.6 mm SL); MNHN 1996-1082 (1, 215.1 mm SL); MNHN 1996-1083 (1, 218.3 mm SL); MNHN 1996-1087 (1, 171.5 mm SL): rio Urubu , Salto Lindóia, c. 2°37’S, 59°22’W; M. Jégu, Sept–Oct 1993 . MCZ 92873 (1, 102.7 mm SL): Lago Jacaretinga, rio Amazonas, near Manaus; T.J. Zaret et al., 9 Jan 1980 . INPA 16384 (2, 88.5–101.6 mm SL); INPA 16450 (3, 143.4– 293.8 mm SL): rio Amazonas, Ilha do Careiro, Lago do Rei, c . 3°9’S, 59°47’W; Eq. Ictiologia/INPA, June–Oct 1986. USNM 307069 (1, 125.3 mm SL); Rio Negro, Lago Janauari , c. 3°13’S, 60°1’W; P. Bayley, 13 Oct 1977 . INPA 4599 (2, 228.7– 241.4 mm SL): rio Amazonas, Lago do Careiro , Ilha do Rei, c. 3°9’S, 59°47’W; M. Jégu et al., 24 Feb 1986 . INPA 5784 (16, 104.7– 161.9 mm SL); INPA 5785 (8, 65.9–77.5 mm SL); INPA 5787 (14, 99.9– 163.9 mm SL); INPA 11071 (18, 49.1–107.7 mm SL); MZUSP 60310 (4, 53.0– 95.1 mm SL); INPA 16348 (1, 44.8 mm SL); INPA 16390 (119, 27.2–77.1 mm SL); INPA 16432 (59, 42.5–99.0 mm SL); INPA 16430 (29, 34.0– 51.1 mm SL); INPA 16455 (3, 38.2–48.9 mm SL); INPA 16454 (1, 112.9 mm SL); INPA 16444 (1, 44.5 mm SL): rio Solimões , Ilha da Marchantaria, c . 3°14’S, 59°55’W; Eq. Ictiologia/INPA, 1976–1981. INPA 13323 (11, 46.0– 93.7 mm SL); INPA 13346 (9, 41.1–66.6 mm SL); INPA 13315 (15, 38.0–74.0 mm SL); INPA 13311 (28, 30.3–82.7 mm SL); INPA 13320 (43, 14.2–60.9 mm SL); INPA 13316 (2, 42.5–43.4 mm SL); INPA 13319 (14, 36.8–68.1 mm SL); INPA 13306 (1, 59.9 mm SL); INPA 13314 (1, 100.4 mm SL); INPA 13319 (7, 47.6–53.6 mm SL); INPA 13300 (5, 43.6–83.9 mm SL); INPA 13310 (3, 50.8–57.8 mm SL); INPA 13326 (7, 61.6–70.3 mm SL); INPA 13339 (2, 64.0–71.0 mm SL); INPA 13299 (32, 26.4–49.7 mm SL); INPA 13317 (1, 39.8 mm SL); INPA 13303 (1, 60.5 mm SL); INPA 13307 (1, 25.4 mm SL); INPA 13324 (16, 31.9–70.9 mm SL); INPA 13328 (37, 12.7–37.7 mm SL); INPA 13329 (1, 62.5 mm SL); INPA 13309 (1, 34.7 mm SL); INPA 13321 (4, 39.4–57.2 mm SL); INPA 13327 (1, 64.6 mm SL); INPA 13312 (1, 37.6 mm SL); INPA 13301 (2, 28.8–40.3 mm SL); INPA 13302 (2, 16.9– 32.7 mm SL); INPA 13318 (7, 40.0–65.0 mm SL): rio Solimões , Ilha da Marchantaria, c. 3°14’S, 59°55’W; P. Petry & R. Sotero, Jan–March 1993 . MZUSP 75565 (3, 72.8–80.9 mm SL); MZUSP 74668 (16, 44.8–66.5 mm SL); USNM 307081 (237, 13.4–31.6 mm SL); USNM 307028 (31, 13.5–19.4 mm SL); USNM 307064 (80, 13.0– 39.0 mm SL); USNM 371013 (10, 35.1–53.7 mm SL); USNM 371014 (1, 80.8 mm SL); USNM 307065 (2, 61.5– 66.9 mm SL); USNM 307032 (5, 31.0– 82.6 mm SL); USNM 307072 (7, 57.9–86.2 mm SL); USNM 307071 (261, 16.4–66.7 mm SL); USNM 307061 (2, 158.3–162.0 mm SL); USNM 307002 (1, 110.1 mm SL); USNM 307023 (1, 73.7 mm SL); USNM 307018 (2, 75.7–84.1 mm SL); USNM 307060 (2, 159.6– 174.6 mm SL); USNM 307024 (6, 27.9–86.2 mm SL): rio Solimões , Ilha de Marchantaria, c. 3°14’S, 59°55’W; P. Bayley, 1977–1979 . INPA 16421 (2, 29.2–40.7 mm SL): “Lago Janauacá com Marchantaria”; Eq. Ictiologia/INPA, 19 Jan 1977. MZUSP 75567 (2, 114.6– 116.3 mm SL); MZUSP 75568 (2, 108.0–117.0 mm SL); USNM 307062 (1, 160.5 mm SL); USNM 307014 (4, 59.7–76.5 mm SL); USNM 371015 (1, 126.2 mm SL); USNM 307070 (3, 108.5–124.0 mm SL); USNM 307154 (3, 43.5–96.2 mm SL); USNM 307006 (12, 18.6–46.6 mm SL); Rio Solimões, Lago Janauacá lakes complex, c. 3°22’S, 60°12’W; P. Bayley, 1977–1979. INPA 16451 (4, 37.4–54.9 mm SL) ; INPA 16364 (1, 156.7 mm SL): rio Solimões , Lago Janauacá, c . 3°24’S, 60°18’W; Eq. Ictiologia/INPA, Jan 1977. ZUEC 7823 (1,159.1 mm SL): Manaquiri, Lago Janauacá , c. 3°24’S, 60°18’W; V.S. Uieda, 11–12 Aug 1979 . ZUEC 5345 (1, 89.9 mm SL): Manaquiri, Lago Janauacá , c. 3°24’S, 60°18’W; U. Caramaschi, July 1977 . MZUSP 6627 (3, 123.1– 149.5 mm SL): igarapé tributary of Lago Manacapuru , c. 3°17’S . 60°54’W; EPA, 13 Nov 1967. MZUSP 5903 (3, 84.5–176.4 mm SL): Lago Jacaré, right margin of rio Solimões , above Manacapuru, c . 3°30’S, 60°47’W; EPA, 29– 31 March 1967. BMNH 1925.10.28.90 (1, 240.0 mm SL): Manacapuru, Rio Solimões, c. 3°17’S . 60°54’W; Ehrhardt, no date. MZUSP 6306 (1, 164.6 mm SL): Lago Castro, rio Purus at its mouth, c . 3°43’S, 61°27’W; EPA, 7–8 Nov 1967. MZUSP 5990 (1, 70.5 mm SL): rio Purus , at its mouth, c. 3°43’S, 61°27’W; EPA, 1–5 May 1967 . INPA 17122 (1, 207.0 mm SL): rio Purus, mouth of Paraná do Jarí, near lago Arunã , 4°55’33’’S, 62°21’58’’W; L. Rapp Py-Daniel et al., 9 June 2001 . INPA 19106 (1, 178.0 mm SL); MCP 29759 (1, 167.5 mm SL): Maraã, Lago Amanã, mouth of igarapé Uxi , 2°32’42’’S, 64°40’7’’W; W.G.R. Crampton, 14 Dec 1997 . MCP 29757 (1, 162.1 mm SL): Maraã, Lago Amanã, mouth of rio Baré , 2°27’23’’S, 64°43’35’’W; W.G.R. Crampton, 17 Dec 1997 . MZUSP 27924 (2, 122.9– 165.6 mm SL): Lago Mamirauá, mouth of rio Japurá , c. 2°59’S, 64°56’W; P.E. Vanzolini, 25 Sept 1983 . INPA 19108 (1, 139.6 mm SL): rio Solimões , Reserva Mamirauá, Lago Mamirauá; W.G.R. Crampton, Oct 1993 . INPA 19118 (1, 39.0 mm SL): rio Solimões , Reserva Mamirauá, Lago Secretaria; W.G.R. Crampton, March 2001 . INPA 19107 (2, 119.6– 133.5 mm SL): rio Solimões , Reserva Mamirauá, lago Curuçá; W.G.R. Crampton, 4 Nov 1997 . MCP 29758 (1, 143.1 mm SL): Alvarães, Lago Rato (channel), Lago Mamirauá system, 3° 2’58’’S, 64° 51’31’’W; W.G.R. Crampton, 11 Oct 1999 . INPA 19111 (1, 159.6 mm SL): Tefé, rio Solimões , Lago Capivara, Costa das Capivaras; W.G.R. Crampton, 13 Jan 2001 . MCZ 162214 (1, 196.0 mm SL): Tefé , 3°24’S, 64°45’W; L. Agassiz et al., Oct 1865 . INPA 19109 (1, 167.1 mm SL): rio Tefé , Ilha do Martelo; W.G.R. Crampton, 14 July 1999 . MNHN 1909-0289 (1, 153.5 mm SL): Rio Solimões, Tonantins , 2°52’S, 67°46’W; C. Jobert, no date . MZUSP 55821 (1, 23.4 mm SL): rio Solimões , 17.1 km downstream rio Içá, 3°0’27’’S, 67°52’46’’W; J.P. Friel et al., 22 Nov 1993 . MZUSP 56153 (3, 24.3–38.6 mm SL): rio Solimões , 26.1 km downstream rio Içá, 2°58’5’’S, 67°49’51’’W; J.P.Sullivan et al., 23 Nov 1993 . MZUSP 27334 (2, 236.0–237.0 mm SL): Benjamin Constant, Costa do Capacete, rio Solimões , c. 4°20’S, 69°58’W; L.P . Portugal, 13 Nov 1982. MZUSP 27330 (1, 184.0 mm SL): Tabatinga, Lago Caial, rio Solimões , c. 4°20’S, 69°58’W; L. P . Portugal, 8 Oct 1982. MNRJ 11262 (1, 209.5 mm SL): rio Queixito, at its mouth at rio Javari , 4°20’S, 70°12’W; A. Parko, 1942 . Amazonas state, rio Uatumã basin: INPA 5685 (1, 258.0 mm SL): rio Uatumã, Balbina , c. 1°55’S, 59°28’W; M. Jégu, Sept 1985 . INPA 15421 (2, 286.1– 292.8 mm SL): rio Uatumã, Balbina , c. 1°55’S, 59°28’W; P. Chaves, July 1985 . INPA 16433 (2, 270.2– 284.2 mm SL): rio Uatumã , igarapé do Barreto, c . 1°58’S, 59°27’W; Eq. Ictiologia/ INPA, 27 April 1983. INPA 5517 (1, 274.7 mm SL): rio Uatumã , igarapé do Arraia; S. Amadio, May 1985 . INPA 16428 (1, 287.5 mm SL): igarapé do Arraia, rio Uatumã ; Eq. Ictiologia / INPA, 15 April 1983 . INPA 16429 (1, 289.4 mm SL): Amazonas, igarapé Água Branca, rio Pitinga (trib. rio Uatumã ), c. 0°52’S, 59°27’W; P. Chaves, 17 Oct 1983 . INPA 16374 (1, 228.9 mm SL): igarapé da Água Branca, rio Pitinga , c . 0°52’S, 59°27’W; Eq. Ictiologia / INPA, 17 April 1983. Amazonas state , rio Negro basin: MCZ 15995 (2, 27.9–32.3 mm SL) : Rio Negro, Lago Aleixo , c. 3°5’S, 59°53’W;. V.R. Thayer, 1865. BMNH 1943.4 .24.37 (1, 196.3 mm SL): “ Manaos ”; J.C. Anthony, no date . MZUSP 9574 (1, 178.3 mm SL): Manaus (fish market); EPA, 17–19 Sept 1968. MZUSP 6766 (1, 206.0 mm SL): Manaus, igarapé Tarumãzinho , trib rio Negro, c. 3°3’S, 60°7’W; EPA, 17–18 Nov 1967 . INPA 15925 (1, 344.0 mm SL): rio Negro, Maruauru (not located); Cidomar, March 2000 . MZUSP 61882 (5, 394.5– 412.5 mm SL): rio Puduari , upper portion, c. 2°8’S, 61°15’W; G. Borges, Nov 1981 . MZUSP 105603 (14, 235.7– 428.2 mm SL): rio Negro, Praia Grande , c. 2°31’S, 69°59’W; G. Borges, 23 May 1982. INPA 2614 (1, 340.9 mm SL) : rio Negro, Praia Grande , c. 2°31’S, 69°59’W; Eq. Ictiologia, 2 Jan 1984 . UMMZ 217848 (1, 221.5 mm SL): Arquipélago de Anavilhanas, rio Negro; W.F. Fink et al., Jan 1983 . UMMZ 217803 (1, 229.4 mm SL): rio Negro, lago “ Chiclaua ” (not located); W.L. Fink, 10 Jan 1983 . INPA 9900 (1, 254.7 mm SL): rio Jaú, igarapé Miratuca , c. 1°58’S, 61°30’W; M. Garcia & Oliveira, 29 Oct 1994 . INPA 11072 (20, 34.4–48.9 mm SL); MZUSP 60311 (8, 31.4–51.8 mm SL): Rio Negro, Anavilhanas , c. 2°31’S, 69°59’W; Eq. Ictiologia / INPA, 28 May 1976 . INPA 16447 (13, 222.6– 316.8 mm SL): rio Negro, “ Ponta da Piraíba ” (not located); Eq. Ictiologia / INPA, 15 Aug 1985 . MNRJ 6268 (1, 147.4 mm SL): rio Negro, “ Uyipiranga ” (not located) ; A. Parko, 1941 . Amazonas state, rio Madeira basin: MZUSP 7039 (11, 169.8– 269.7 mm SL): rio Canumã , c. 4°2’S, 59°6’W; EPA, 28–29 Nov 1967 . MZUSP 59001 (1, 270.8 mm SL): mouth of rio Madeira (purchased at the Itacoatiara fish market) ; A.M. Zanata, 3 Aug 1996. MCZ 21090 (1, 203.8 mm SL) : Rio Madeira, probably near confluence with rio Solimões ; L. Agassiz et al., 1 Sept 1865 . Rondônia state, rio Madeira basin: MZUSP 14017 (4, 301.0– 348.6 mm SL): rio Machado , at its mouth, 8°4’S, 62°53’W; M.Goulding, 18 Sept 1977 . UF 100627 (1, 194.0 mm SL): rio Jamari, ca. 20 km downstream from Samuel dam, locally called Pedra de Sant'anna, c . 8°44’S, 63°29’W; J. P. Viana, 3 June 1993. INPA 16383 (11, 133.0– 156.8 mm SL): rio Jamari , Samuel dam, diverting channel (cofferdam), c . 8°45’S, 63°27’W; G.M. Santos, 7–9 June 1988. INPA 16456 (1, 383.4 mm SL): rio Jamari, 5 km above Samuel dam, c. 9°32’S, 63°8’W; G.M. Santos, 14 July 1985 . INPA 16442 (2, 282.8– 303.2 mm SL): rio Jamari, above Samuel dam, c. 9°32’S, 63°8’W; G.M. Santos, 7 Dec 1984 . INPA 16443 (2, 273.9– 318.5 mm SL): rio Jamari below Samuel dam, c. 8°30’, 63°29’W; G.M. Santos, 27 March 1986 . CAS 96131 (1, 207.0 mm SL): Rio Madeira, “ Cachoele de Theotone ” [= Cachoeira do Teotônio , 8°52’S, 64°3’W]; J.D. Haseman, 30 Oct 1909 . CAS 18395 (1, 273.0 mm SL): Rio Madeira, “whirlpools at Cachoele de Girao ” [= Cachoeira do Girau , 9°17’S, 64°39’W]; J.D. Haseman, 26 Oct 1909 . MZUSP 88028 (1, 194.0 mm SL): rio Madeira, Estação Ecológica Antônio Mujica Nava , 9°24’50’’S, 64°56’32’’W; L.F. Silveira, 6–18 Feb 2002 . MCP 39586 (1, 188.4 mm SL): Igarapé Taquarás , trib. Rio Mamoré, BR-425, 9°57’43’’S, 65°17’45’’W ; A.R. Cardoso, V. Bertaco, F.C.T . Lima & J.F. Pezzi da Silva, 25 Jul 2004. INPA 16371 (1, 249.0 mm SL): rio Novo, trib. rio Guaporé , at its mouth, c . 10°52’S, 65°16’W; G.M. Santos, 20 June 1985. INPA 16375 (2, 192.7– 207.4 mm SL): Guajará-Mirim, rio Pacaás Novos (trib. rio Guaporé ), c . 11°5’S, 65°8’W; G.M. Santos, 16 Nov 1984. INPA 16377 (1, 185.5 mm SL): rio Mamoré, mouth of rio Guaporé, Surpresa , 11°53’S, 65°1’W; G.M. Santos, 19 June 1984 . AMNH 39956 (1, 392.4 mm SL): Rio Guaporé, 5 km SW Costa Marques, c. 12°30’S, 64°17’W; R.M. Bayley et al., 23–24 Sept 1964 . Mato Grosso state, rio Madeira basin: MZUSP 105602 (2, 420.0–485.0 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 . Bolivia, rio Madeira basin: FMNH 107242 (1, 445.0 mm SL): Estado Pando , Río Nareuda (trib. Río Orthon, Río Madre de Dios drainage), c. 11°16’S, 69°3’W; N . A. Menezes et al., 4 Sept 1996 . MNHN 1989–1430 (3, 140.2– 158.8 mm SL): Estado Beni , Río Tijamuchi (trib. Rio Beni), below Trinidad, c. 14°11’S, 65°3’W; L. Lauzanne & G. Loubens, 26–28 Apr 1984 . Peru, Depto. Loreto , Rio Ucayali /Amazonas basin: NRM 23671 (1, 113.7 mm SL); NRM 23672 (1, 123.8 mm SL): Quebrada Tocón Grande and marginal pools, at km 33 of carretera Iquitos-Nauta, Río Itaya drainage, c. 4°2’S, 73°26’W; S.O. Kullander et al., 3–4 Jul 1986 . MZUSP 15266 (2, 87.2–90.7 mm SL): Caño Lupuna, Río Amazonas (not located); M.V. Correa , 10 Jun 1980 . INHS 55030 (1, 118.0 mm SL): south bank trib. Río Napo, near Mazán, ca. 33 km Iquitos ,c. 3°30’S, 73°6’W; M.H. Sabaj et al., 31 Jul 1999 . INHS 43857 (1, 95.9 mm SL): small cocha trib. Río Napo, Isla Milagros across the town of Mázan, 3°28'59,9'’S, 73°05'05,5'’W; M.H. Sabaj et al., 2 Aug 1997 . INHS 106469 (1, 134.4 mm SL): Río Nanay, Pampa Chica, 3°45'08,8'’S, 73°17'00,1'’W; M.H. Sabaj & J.W. Armbruster, 22 Jul 1997 . CAS 16031 (1, 293.7 mm SL); CAS 68880 (1, 198.4 mm SL): Rio Amazonas, Iquitos; W.R. Allen, Sept 1920 . CAS 160579 (1, 132.4 mm SL); CAS 160749 (1, 120.7 mm SL); CAS 136578 (1, 164.3 mm SL): Cano del Shansho, near Pebas , c. 3°21’S, 71°48’W; W.G. Scherer, Sept 1936 . ANSP 178374 (3, 114.2– 162.7 mm SL): Prov. Maynas, Río Yanuyacu (trib. R. Amazonas at mouth of Cano Chincana, Emerald Forest Lodge, approx. 25 miles S. of Iquitos; M.H. Sabaj et al., 11 Aug 2001. MUSM 7020 (1, 134.5 mm SL) : Río Pacaya, Cocha Zapote , 5°75’S, 74°25’W; H.W. Koepcke, March 1960. MUSM 18177 (1, 40.8 mm SL): San Pablo de Tipishca , Río Marañon; H. Ortega et al., 15 Apr 2001 . Depto. Ucayali , Río Ucayali basin: MZUSP 26219 (3, 58.9–60.8 mm SL); MZUSP 26218 (3, 60.7–66.1 mm SL): Río Ucayali, Shanahao, Prov. Coronel Portillo; H. Ortega, 29 Apr 1976 . MZUSP 25937 (6, 1 cs, 27.7–52.0 mm SL); AMNH 43338 (2, 66.1–73.5 mm SL); MUSM 41144 (1, 50.7 mm SL): Río Ucayali, Masisea , Prov. Coronel Portillo, 8°35’S, 74°20’W; H. Ortega, 21–23 Nov 1973 . MUSM 41154 (1, 148.8 mm SL): Pucallpa, Río Ucayali, Masisea , 8°35’S, 74°20’W; H. Ortega, 24 Sept 1975 . MUSM 108 (2, 133.0–134.0 mm SL): Ucayali, Pucallpa, Masisea, Lobococha , 8°35’S, 74°20’W; H. Ortega, 20 Apr 1983 . MUSM 315 (2, 130.5–132.0 mm SL): Pucallpa, Río Ucayali, Utiquinía , 8°12’S, 74°34’W; H. Ortega, 20 Sept 1985 . Colombia, Rio Amazonas basin: UMMZ 191053 (1, 225.5 mm SL): Leticia , Rio Amazonas, 4°13’S, 69°57’W; R. Faber, 17 May 1971 . Venezuela, rio Orinoco basin, Estado Delta Amacuro: USNM 236562 (50, 122.7– 297.8 mm SL): tidal stream on river shore, 49 miles from sea buoy, 8°37’36’’N, 60°49’36’’W; J.N. Baskin & D.J. Stewart, 20 Nov 1979 . Estado Anzoategui: ANSP 166777 (1, 172.0 mm SL): Soledad , Laguna Curita, 8°9’30’’N, 63°35’55’’W; M. Rodriguez, 27 Apr 1988 . ANSP 166480 (4, 149.5– 170.9 mm SL): Soledad , Laguna Aguilera, 8°11’30’’N, 63°26’45’’W; M. Rodriguez & S. Richardson, 22 Jan 1987 . Estado Guárico: MZUSP 54583 (2, 142.9– 145.2 mm SL): Santa Rita , Río Aguaro, near Santa Rita, 8°9’N, 66°14’W; J. Moscó et al., 22 Nov 1968 . INHS 33942 (3, 122.8– 137.7 mm SL): Pozo Azul (Río San Bartolo), P.N. Aguaro-Guariquito; W. Mejo et al., 4 Jan 1995 . INHS 34335 (1, 217.5 mm SL): Río Aguaro, P.N. Aguaro-Guariquito, 15 km S Paso Cachimbo , 8°3’6’’N, 66°25’34’’W; D.C. Taphorn et al., 10 Jan 1995 . FMNH 85402 (6, 80.5–98.1 mm SL): borrow pit west of road, 9.7 km N of Cabruta , c. 7°43’N, 66°15’W; J.E. Thomerson et al., 5 Jan 1975 . LBP 10224 (4, 128.2– 148.1 mm SL): Cabruta , Río Apure, 7°37’24’’N, 66°24’48’’W; C. Oliveira & V. Tagliacollo, 21 Apr 2010 . Estado Barinas: FMNH 103954 (1, 154.6 mm SL): Playa Los Chicos in the Rio Suripá, ca. 2.5 hrs. above Hato Las Mercedes , c. 7°47N, 70°9’W; B. Chernoff et al., 12 Jan 1991 . Estado Apure: INHS 27660 (2, 163.5– 184.4 mm SL): Caño Potrerito , hwy. bridge between San Fernando and Puerto Paez, 6° 24’48’’N, 67°31’56’’W; L.M. Page et al., 22 Jan 1992 . INHS 61402 (1, 178.5 mm SL): Laguna Larga (Río Cínaruco drainage), 6°33’19’’N, 67°24’49’’W; L.M. Page et al., 19 Jan 1992 . ANSP 165393 (1, 144.4 mm SL): Rio Claro, 15 km S of La Montaripa on San Fernando de Apure—Puerto Paez Hwy., 7°10’N, 67°25’W; S. Schaefer et al., 7 Nov 1989 . ANSP 165548 (3, 120.5–129.0 mm SL): flooded savannah ca. 2.0 km S of intersection of Rio Claro and San Fernando de Apure— Puerto Paez hwy., 7°10’N, 67°25’W; S. Schaefer et al., 7 Nov 1989 . ANSP 165483 (1, 232.0 mm SL): Río Capanaparo, backwater lagoon (mouth of caño Las Varitas ) near San Fernando de Apure—Puerto Paez hwy., 7°2’N, 67°25’W; S. Schaefer et al., 7 Nov 1989 . FMNH 69900 (1, 159.3 mm SL); FMNH 117234 (1, 170.0 mm SL): Río Cinaruco at confl. Madre about 60 miles S. of San Fernando de Apure, c. 6°33’N, 67°18’W; W.P. Braker & Zunwalt, Feb 1967 . Estado Bolívar: ANSP 159722 (1, 125.3 mm SL) : Río Guacamayo , below bridge at crossing of Caicara-Ciudad Bolivar hwy., 7°40’N, 64°10’W; B. Chernoff & F. Provenzano, 21 Nov 1985 . ANSP 159726 (33, 99.1–144.4 mm SL): Caño crossing road to Las Trincheras, 2.7 km of intersection with Ciudad Bolivar-Caicara hwy., 7°22’N, 64°59’W; W. Saul et al., 20 Nov 1985 . ANSP 159720 (5, 104.6–220.0 mm SL): Río Agua Blanca , below bridge at crossing of Caicara-Ciudad Bolivar hwy., 7°50’N, 63°51’W; B. Chernoff et al., 21 Nov 1985 . ANSP 159727 (1, 117.3 mm SL): Río Caura at Maripa ferry crossing, 7°27’N, 65°12’W; B. Chernoff et al., 19 Nov 1985 . ANSP 159728 (2, 124.3– 194.7 mm SL): morichal Poso Vagabundo , 3 km E of Maripa, just off Caicara-Ciudad Bolivar hwy., 7°25’30’’N, 65° 9°59’W; W. Saul & R. Royero, 19 Nov 1985 . ANSP 135720 (1, 146.5 mm SL): Morichal Zamorai (caño), between Río Tauca and Río Tiquire , Maripa-Ciudad Bolivar hwy., 7°28’N, 64°54’W; J.E. Boehlke et al., 7 Feb 1977 . ANSP 135840 (2, 238.0–245.0 mm SL): mouth of small caño feeding Río Caura 15 min downstream from “hydrographic plant”, 6°20’N, 64°30’W; J.E. Boehlke et al., 22 Jan 1977 . CAS uncat. (1, 152.0 mm SL); CAS 156831 (3, 134.6– 167.9 mm SL): Caño de Quiribana, near Caicara , c. 7°36’N, 66°11’W; C. Ternetz, April–May 1925 . CAS 154565 (1, 156.1 mm SL); CAS 154568 (1, 134.9 mm SL): Rio Orinoco, mouth of Cano de Quiribana, Caicara , c. 7°36’N, 66°11’W; C. Ternetz, 5 May 1925 . CAS 156758 (1, 130.1 mm SL): creeks into Laguna San Raphael, Caicara , c. 7°36’N, 66°11’W; C. Ternetz, 28 Apr 1925 . LBP 3026 (8, 113.7– 141.8 mm SL): Caicara del Orinoco , Río Orinoco, 7°38’12’’N, 66°19’4’’W; C. Oliveira & A . Granado, 2 Oct 2005 . ANSP 159740 (14, 85.4–130.1 mm SL): Cano Caiman, at crossing of Caicara-Puerto Ayacucho hwy, 19.2 km of Ciudad Bolivar-Caicara hwy; B. Chernoff et al., 29 Nov 1985 . ANSP 159725 (5, 96.7– 124.3 mm SL): River and flooded area 15 km of Maniapure on Caicara-Puerto Ayacucho hwy (Río Chaviripa?), c. 7°0’N, 66°31’W; B. Chernoff et al., 16 Nov 1985 . ANSP 159724 (16, 91.4–121.7 mm SL): small stream crossing Caicara-Puerto Ayacucho hwy., 18 km N of Maniapure ; B. Chernoff et al., 16 Nov 1985 . ANSP 159737 (2, 100.6– 107.5 mm SL): Río Maniapure at crossing of Caicara-Puerto Ayacucho hwy., 6°55’34’’N, 66°33’32’’W; B. Chernoff et al., 28 Nov 1985 . ANSP 159723 (2, 18.8–110.5 mm SL): Río Caura at Puerto Las Majadas , 7°30’18’’N, 64°50’24’’W; L. Aguana, 23 Nov 1985 . ANSP 159739 (1, 136.2 mm SL): Caño 15.1 km E of Río Parguaza ferry crossing on Caicara-Puerto Ayacucho hwy., c. 6°19’N, 67°6’W; B. Chernoff et al., 28 Nov 1985 . ANSP 159735 (1, 120.3 mm SL): Cano crossing dirt road near Hacienda Fundo Malana , c. 15 km N of Sipao, 7°35’N, 65°22’W; W. Saul & R. Royero, 19 Nov 1985 . ANSP 135771 (1, 144.0 mm SL): Río Urbana (Urbani) on Maripa-Las Trincheras road, 7°18’N, 65°0’W; J. Boehlke et al., 20 Jan 1977 . UF 80418 (2, 129.9– 140.5 mm SL): bridge of Río Chaviripa on Caicara-San Fernando do Atabapo (Puerto Ayacucho) road, c. 7°0’N, 66°31’W; D.C.

Taphorn et al., 16 Apr 1984. UF 80409 (1, 174.1 mm SL); UF 80709 (2, 131.8– 146.5 mm SL); MZUSP 62442 (2, 121.7– 126.6 mm SL): Caño Caripo/Caripito; D.C. Taphorn et al., 17 Apr 1984. FMNH 85678 (1, 157.0 mm SL): Rio Orera, 13 km S. of Puerto Nuevo toward Puerto Ayacucho; J. Thomerson et al., 14 Jan 1975 . Estado Amazonas: ANSP 159738 (1, 127.3 mm SL): Caño 21 km SW of El Burro , Caicara-Puerto Ayacucho hwy., c. 6°0’N, 67°21’W; W. Saul et al., 26 Nov 1985 . FMNH 103953 (1, 162.6 mm SL): mouth of small caño on Río Cuao, 4°58’4’’N, 67°36’55’’W; B. Chernoff et al., 12 Feb 1992 . Guyana: AMNH 14405 (2, 106.5– 106.9 mm SL) ; AMNH 14323 (2, 101.3– 123.9 mm SL): Santa Rosa , Amacuro River, 7°39’N, 58°57’W ; A.S. Pinkus, 1938. Trinidad: USNM 235526 (1, 206.3 mm SL): Chatam stream, south west Trinidad , 10°5’N, 61°45’W; M. Atkins, 5 Sept 1980 . Uncertain locality: MZUSP 3815 (7, 137.1– 151.6 mm SL): “ Amazonas e Pará ”; E. Garbe, 1902. Introduced /escaped stocked specimens (all from Brazil): NUP uncat. (2, 298.5– 310.1 mm SL) : Goiás, Caldas Novas, rio Corumbá, trib. rio Paranaíba ; Nupélia , 1996–2000. MZUSP 54008 (8, 121.7– 203.6 mm SL) : São Paulo, Pirassununga, CEPTA (stocked specimens); 27 Feb 1998 . MZUSP 82418 (6, 85.8–101.4 mm SL); MZUSP 82430 (3, 111.6– 141.4 mm SL): São Paulo, Campinas, artificial pond near rio Atibaia ; A.M. Zanata & M.P. Geraldes, March 2003 . MZUSP 86779 (1, 217.5 mm SL): Rio de Janeiro, Campos, rio Paraíba do Sul (fish market); O.T. Oyakawa et al., Sept 2004 .

Figures

FIGURE 66. Brycon amazonicus, neotype, INPA 3415, 362.0 mm SL: Brazil, Pará, rio Trombetas.

FIGURE 67. Brycon amazonicus, BMNH 1869.5.21: 1, 235.7 mm SL: “ Upper Amazons ”; lectotype of Megalobrycon cephalus Günther.

FIGURE 68. Brycon amazonicus, ANSP 8058, 46.0 mm SL: Peru, Loreto, Río Ampyiacu. Holotype of Brycon capito Cope. Photo by M. W. Littmann.

FIGURE 69. Brycon amazonicus, NMW 62944, 67.7 mm SL: Venezuela, Bolívar, Río Orinoco. Syntype of Brycon longiceps Steindachner.

FIGURE 70. Brycon amazonicus, FMNH 53353, 169.1 mm SL: Guyana, Aruka River. Holotype of Brycon siebenthalae Eigenmann. Photo by P. Willink.

FIGURE 71. Brycon amazonicus, INPA 16428, 287.5 mm SL: Brazil, Amazonas, igarapé do Arraia.

FIGURE 72. Brycon amazonicus, INHS 27660, 184.4 mm SL: Venezuela, Apure, Caño Potrerito.

FIGURE 73. Brycon amazonicus, MZUSP 74668, 66.5 mm SL: Brazil, Amazonas, rio Solimões.

FIGURE 74. Map of northern South America, showing known localities of Brycon amazonicus (red dots) and B. gouldingi (purple dots).

FIGURE 75. Brycon gouldingi, holotype, MZUSP 61400, 374.7 mm SL: Brazil, Pará, igarapé da Boa Vista.

Tables

TABLE 18. Morphometric data of Brycon amazonicus (A: neotype of Chalceus amazonicus, INPA 3415; B: lectotype and paralectotype of Chalceus carpophagus, MNHN 9835 and MNHN 98; C: largest syntype of Brycon longiceps, NMW 62944; D; holotype of Brycon siebenthalae, FMNH 53353).

	A	B	C	D	n	Range	Mean
Standard length (SL)	362.0	260.9–267.8	67.7	169.1	120	67.7–485.0	-
Percentages of standard length
Depth at dorsal-fin origin	33.9	27.9–37.0	31.0	32.9	118	27.0–37.9	31.9
Snout to dorsal-fin origin	49.9	48.9–54.8	52.6	51.0	120	43.6–54.8	49.6
Dorsal-fin base length	11.8	13.3	12.6	11.9	120	9.7–14.1	12.2
Posterior terminus of dorsal fin to adipose fin	25.5	25.7–28.2	21.0	22.9	119	21.0–27.7	24.5
Posterior terminus of dorsal fin to hypural joint	38.6	43.7–47.0	35.6	34.9	120	33.2–47.0	37.6
Snout to pelvic-fin insertion	46.5	47.8–48.9	53.2	48.9	118	43.7–53.2	47.3
Snout to anal-fin origin	67.5	67.0–69.2	99.7	72.8	115	63.1–72.8	67.7
Anal-fin base length	23.0	22.8–23.0	21.0	21.1	119	17.4–25.3	22.0
Caudal peduncle length	15.2	15.1–16.6	16.1	15.9	120	12.8–20.1	15.9
Dorsal-fin height	16.2	19.8	24.5	22.5	116	15.8–24.5	20.8
Pectoral-fin length	20.3	19.0	20.1	20.2	117	16.3–23.1	19.2
Pelvic-fin length	-	13.7–17.1	19.6	17.2	112	10.1–19.6	16.0
Caudal peduncle depth	9.7	8.0–10.6	9.6	10.0	120	8.1–10.4	9.4
Head length	24.9	25.5–26.0	32.9	26.5	120	22.0–33.9	26.7
Percentages of head length
Head height	84.0	78.5–87.6	75.3	81.7	119	70.0–91.2	80.6
Snout length	36.2	31.8–33.1	29.1	33.3	120	27.0–39.2	32.7
Upper jaw length	48.1	46.6–48.8	44.8	44.2	118	43.3–51.6	46.2
Horizontal eye diameter	20.3	22.7–25.0	32.3	23.9	120	17.7–33.3	25.0
Post-orbital length	48.9	43.8–46.4	40.8	46.4	120	40.1–51.5	47.0
Least interorbital width	50.7	47.1–47.3	33.2	47.3	120	33.2–52.1	45.3