Brycon nattereri Günther, 1864

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 : 75-82

Brycon nattereri Günther, 1864

( Figs. 44–48 )

Chalceus opalinus (not Cuvier): Kner, 1860: 10 (“Irisanga”).

Salmo pira-pitinga Kner (ex Natterer), 1860: 2 (name unavailable, published under the synonym of Chalceus opalinus ).

Brycon nattereri Günther, 1864: 334 (Type locality “Irisanga”); Bertoni, 1939: 55 (listed, Paraguay); Shibatta et al., 2002: 409, 411, 414 (Rio Iapó, rio Tibagi basin, Paraná); Vieira et al., 2005: 80 –84, fig. 2d (Rio Cipó; Serra do Cipó National Park; reproduction); Luz-Agostinho et al., 2006: 64 (Corumbá reservoir, rio Corumbá; diet); Lima et al., 2008a: 207 –208 (illustration; ecology, conservation); Lima et al., 2008b: 50 –52 (ecology, distribution, conservation); Pompeu et al., 2009: 663 –664 (Rio Capivarí, upper rio Grande drainage, Minas Gerais; conservation); Bartolette et al., 2012: 62 (Brazil, Goiás, Serra da Mesa dam); Vitorino Jr. et al., 2014: 421 –425 (Rio das Almas basin, upper rio Tocantins; seasonal abundance); Travenzoli et al., 2015: 6, 8–11, 13–14 (Rio Paranaíba basin, Goiás; cytogenetics, phylogenetics relationships, molecular taxonomy). [Not Amaral-Campos, 1950: 139–140].

Brycon reinhardti Lütken, 1875a: 134 –135 (Type locality “flumine Rio d. Velhas”); Lütken, 1875b: 221 –223 (description; Rio das Velhas); Eigenmann & Ogle, 1907: 30 (Rio das Velhas); Howes, 1982: 42 –43 (discussion; syntype BMNH 1876.1.10:36); Alves & Pompeu, 2003: 174 (Rio das Velhas basin; conservation status); Lima, 2003: 177 (synonymization with Brycon nattereri ). [Not Steindachner, 1876: 27–29; Travassos & Silva-Santos, 1955: 309; Narahara, 1993: 5–6; Almeida-Toledo et al., 1996: 36 –37].

Brycon cf. nattereri: Caramaschi et al., 2012: 49 (Brazil, Goiás, Serra da Mesa dam; abundance).

Diagnosis. Brycon nattereri can be diagnosed from all remaining cis-andean Brycon species, with the exception of B. stolzmanni , B. coxeyi , B. coquenani , B. vermelha , B. insignis , B. howesi , B. dulcis , B. ferox , B. vonoi , and B. opalinus by possessing a color pattern consisting in a humeral blotch and a caudal peduncle blotch, without body stripes or other obvious color markings on caudal and anal-fins (vs. body stripes and caudal/anal fin color markings present; see Fig. 5 ). Brycon nattereri can be distinguished from B. ferox , B. vermelha , B. insignis , B. howesi , B. coquenani , and B. dulcis by possessing a rounded, obtuse head profile (vs. a distinctly acute head profile), and by possessing a caudal peduncle blotch extending into middle caudal-fin rays (vs. caudal peduncle blotch not extending into middle caudal-fin rays). Brycon nattereri can be distinguished from B. stolzmanni and B. coxeyi by the absence of a patch of dark pigmentation on the opercle (vs. dark patch of pigmentation present on opercle). Brycon nattereri can be additionally distinguished from B. insignis , B. howesi , B. coquenani , and B. vermelha by possessing a fifth infraorbital bone about as wide as high (vs. fifth infraorbital bone wider than high; see Fig. 6 ). Brycon nattereri can be distinguished from B. opalinus by possessing lateral line tubules with 2–5 branches (vs. tubules mostly simple), and caudal peduncle blotch extending into middle caudal-fin rays (vs. caudal peduncle blotch not extending into middle caudal-fin rays).

Description. Morphometric data are presented in Table 13 . Middle-sized species, largest examined specimen 300.3 mm SL. Body slender to moderately slender. Largest body height slightly ahead of dorsal-fin origin. Dorsal body profile slightly convex from upper lip margin to vertical through anterior naris, slightly convex from latter point to basis of supraoccipital process, moderately to pronoucedly 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 moderately acute anteriorly, mouth terminal. Jaws isognathous to slightly anisognathous, premaxillary projecting slightly relative to dentary in some specimens, leaving outer row of premaxillary teeth exposed when mouth is closed. Maxillary moderately long, extending posteriorly to anterior margin to anterior third of pupil. Adipose eyelid well developed. Premaxillary teeth in three rows; teeth of third row largest. Five (1), 6 (7), 7 (6), 8 (18), 9 (16), 10 (16), 11 (4), 12 (3), or 14 (1) tricuspidate teeth in outer series. Three (4), 4 (37), 5 (23), or 6 (5) tri- to pentacuspidate teeth in second, inner premaxillary row, plus 2 (20), 3 (48), or 4 (4) 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 with distal portion expanded and rounded in profile. Twelve to 26 maxillary teeth, slightly smaller than teeth of first premaxillary row, anterior teeth tricuspidate, posterior teeth unicuspidate. Dentary with 8 (2), 9 (9), 10 (15), 11 (7), 12 (9), or 14 (2) teeth in main series. Anterior four dentary teeth assymetrical, considerably larger and bulkier than remaining teeth, tetra- to pentacuspidate, each with central cusp distinctly larger than remaining cusps. Remaining dentary teeth progressivelly smaller, tri- 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 16–24 small, unicuspidate teeth, originating on lingual crest of dentary replacement trench at the level of fourth to sixth main series dentary teeth.

Scales cycloid. Lateral line complete, from supracleithrum to caudal-fin base. Forty-six (2), 47 (4), 48 (2), 49 (11), 50 (11), 51 (15), 52 (12), 53 (6), 54 (5) ou 55 (6) scales in lateral line series. Laterosensory tube simple in specimens smaller than 95 mm SL, ramified in specimens larger than 100 mm SL. Tubules ramification increasing in complexity along ontogeny, specimens between 100–150 mm SL with tubules with two or three branches, larger specimens (> 180 mm SL) typically developing ascendant and descendant main branches and 2–5 secondary branches per scale. Horizontal scale rows between dorsal-fin origin and lateral line 8 (44) or 9 (28). Horizontal scale rows between lateral line and pelvic-fin 3 (2), 4 (49), or 5 (21). Circumpeduncular scales 15 (3), 16 (24), 17 (29), 18 (15), or 19 (3).

Dorsal-fin rays ii, 9. Dorsal fin origin slightly ahead middle of SL. First dorsal-fin pterygiophore inserting behind neural spine of 15th (1) vertebra. Anal-fin rays iii (not including first, small unbranched ray only visible in the cs specimen), 18 (5), 19 (13), 20 (20), 21 (19), 22 (12), 23 (1), 24 (1), or 25 (1). First anal-fin pterygiophore inserting behind haemal spine of 26th (1) vertebra. Last unbranched and anterior 4–5 branched anal-fin rays longer, remaining rays progressively shorter towards anal-fin end. Anal fin displaying numerous (c. 20 per fin-ray main branch) small hooks on last unbranched and posterior main branch of branched rays 1–20, associated with dense, gelatinous tissue in a single specimen (CAS 79218, 204.2 mm SL). A single hook per ray segment, a few hooks at the anterior branch of some anal-fin rays. Sheath of scales covering basis of anal-fin rays composed of two scale rows, lower scale row formed by 16–21 rectangular scales. Pectoral-fin rays i, 12 (18), 13 (37), or 14 (18). Pelvicfin rays typically i, 7. One specimen (CAS 79218, 204.2 mm SL) with minute hooks on distal portion of posterior branch of branched pelvic-fin rays. Main caudal-fin rays 10/9. Caudal fin forked, lobes rounded.

Four branchiostegal rays, three on anterior ceratohyal and one on posterior ceratohyal. First branchial arch with 11 (1), 12 (11), 13 (5), or 14 (1) lower, 1 at angle, and 8(1), 9 (7), 10 (7), or 11 (3) upper gill rakers. Vertebrae 46 (3). Supraneurals 10 (1).

Coloration in alcohol. Top of head, snout, supraorbital, sixth infraorbital, and dorsal portion of body lightgrey to dark-brown. Second, third, fourth, and fifth infraorbitals, and opercle silvery except in specimens that lost most guanine, in which case brownish. Dentary, maxillary, gular area and lower portion of body light brown. Lateral portion of body silvery in specimens retaining guanine, brownish in specimens that were stored for a long period in formalin/alcohol. Humeral blotch present, relatively conspicuous in juveniles but little conspicuous in adult specimens, approximately rounded in shape, situated immediately above lateral line, its anterior margin at level of second, extending longitudinally to posterior margin of third to fourth lateral line scales, and vertically one and half scales high. Large, generally very conspicuous, oval-shaped caudal peduncle blotch, extending along 6–9 last lateral-line scales. Caudal peduncle blotch extending into middle 4–6 caudal fin-rays, often extending to the distal portion of middle caudal rays, forming a distinct caudal-fin stripe. Rayed fins clear, with dark chromatophores scattered over the interradial membranes. Adipose fin light-grey to light-brown. Juveniles (up to 100 mm SL) with narrow, wavy, irregularly-distributed vertical lines formed by dark pigmentation concentrated on anterior and posterior scales margins. Specimens from rio Cipó basin in upper rio São Francisco drainage (MZUSP 51052, MZUSP 58948, MZUSP 58949, MZUSP 58950) with overall body color, including fins, dark-brown, with scales on lateral portion of body with darkened margins (see item “Variation”, below).

Color in life. Description based on pictures of several unpreserved specimens fished in several portions of the upper rio Paraná basin in Minas Gerais and upper rio Tocantins basin in Goiás, and from photographs of the specimens MZUSP 45793 and MNRJ 19893 immediatelly after collection. Dorsal area, top of head and snout lightgrey to light brown. Infraorbitals, opercular bones and sides of body silvery. Dark peduncular blotch very conspicuous. Fins (including adipose fin) yellowish to reddish.

Common names. “Peripetinga” (Lütken, 1875, 2001: 222), “ pirapitinga ”, “tabarana”, “tubarana”. The name “tabarana” (from which “tubarana” is a variant) is more often employed for Salminus hilarii in southeastern Brazil.

Distribution. Distributed in headwater areas in the upper rio Paraná, upper rio Tocantins and upper rio São Francisco basins, central and eastern Brazil ( Fig. 43 ). Bertoni (1939) listed the species as occurring in Paraguay. Though the occurrence of Brycon nattereri in the upper rio Paraná portion draining Paraguay is not unlikely, recent fish collections in that country (e.g. Géry & Mahnert, 1992) failed to obtain any specimens of this species, and this record is herein considered doubtful.

Variation. Specimens collected at the rio Cipó, a tributary of the rio das Velhas (rio São Francisco basin) present a general color pattern much more darker than the remaining specimens examined from the upper rio Paraná, upper rio Tocantins and other portions of the upper rio São Francisco basins. This overall dark pigmentation is very likely a phenotypical response to the dark waters of the rio Cipó (F. Vieira, pers. comm.), a fact also observed in the Brycon species occurring in the Amazon basin (see under B. amazonicus , below), and some other Brycon species from eastern Brazil (see species accounts of B. howesi , B. dulcis , and B. opalinus , above). Specimens from the upper rio Araguari, a tributary of the rio Paranaíba (upper rio Paraná basin) in Minas Gerais (MZUSP 44947 and MZUSP 45793) differ from remaining Brycon nattereri specimens by possessing a considerably convex predorsal profile, well-developed, wide infraorbitals 3–5, and a relatively ill-defined caudal peduncle blotch. There is not, however, a clear geographical pattern, since typical Brycon nattereri are known from the rio Araguari a little downstream of the area inhabited by these specimens. More material, as well as other type of data (e.g., molecular data) are necessary to understand what may lie behind this variation.

Ecological notes. Brycon nattereri is apparently restricted to clear- to dark-water, middle-sized rivers, with moderate to swift current, in headwater areas provided with well preserved riparian vegetation. Largest recorded size is 31 cm SL ( Lima et al., 2008b). A 51 cm SL and 2.6 kg specimen recorded as the maximum size for the species by Lima et al. (2008a, b) from the Serra da Mesa area in the upper rio Tocantins was not examined by the author and more likely represents a misidentified specimen, perharps of the sympatric, large-sized Brycon gouldingi . Brycon nattereri has an omnivorous, highly opportunistic diet. In the upper rio Tocantins area, its diet was almost entirely composed of allochtonous items, especially seeds and fruits (though only fruits of Chrysobalanaceae and Caryocar sp. could be identified) and terrestrial arthropods (mainly beetles and ants). A lizard was recorded in the stomach of a 12 cm SL specimen. Smaller individuals tended to be more carnivorous, whereas larger specimens relied more heavily on plant material ( Lima et al., 2008b). Diet preferences of Brycon nattereri in the upper Paraná basin pointed to terrestrial and aquatic insects, detritus, small fish, and algae (Luz- Agostinho et al. 2006), in addition to fruits and other vegetal items ( Lima et al., 2008b). Smallest first maturation lengths recorded in the upper rio Tocantins basin were for females 11.4 and for males 9.8 cm SL, and in the upper rio Paraná basin 18.5 cm SL and 15.8 cm SL, respectively ( Lima et al., 2008b). Breeding individuals were detected during the middle dry season (May to July) in the upper rio Corumbá, rio Paraná basin and late dry season (June to August) in the upper rio Tocantins ( Lima et al., 2008a). In the upper rio Araguari basin (upper rio Paraná basin), however, breeding individuals were mainly detected in the late rainy season (March to April; Lima et al., 2008b). A population of Brycon nattereri was reported to breed in a small river stretch, limited by waterfalls ( Vieira et al. 2005), which strongly suggests that the species does not undertake long spawning migrations. Shortscale migratory behavior for the species was inferred from a seasonal fluctuation in abundance along the year in a tributary of the rio das Almas (upper rio Tocantins) ( Vitorino Jr. et al., 2014). Very likely, the reproductive strategy of Brycon nattereri seems to fit the seasonal (periodic) type (sensu Winemiller & Rose, 1992). Juveniles (17–100 mm SL) are often collected in streams, which appear to be the recruitment areas for the species.

Conservation. The decline of Brycon nattereri populations seems to be related to three factors, viz., deforestation of the riparian forest, water pollution, and dam building. Although deforestation and water pollution might be ascribed as the main causes of the decline of Brycon nattereri in areas historically more disturbed (e.g. the portion of the upper rio Paraná basin situated at the São Paulo state), construction of hydroelectric dams is a concurrent threat that has been increasing in the last decades. Many of the rivers of former known occurrence of the species are nowadays modified by hydroelectric dams and the species appears to subsist in those areas only at undisturbed tributaries, e.g., at the upper rio Tocantins basin in the Serra da Mesa dam area and at the upper rio Araguari basin in Nova Ponte dam area. Brycon nattereri is considered officially as threatened in Brazil, under the category “vulnerable” (see Lima et al., 2008a, b, for additional information).

Remarks. Brycon nattereri was described by Günther (1864: 334), based on a specimen briefly described and identified by Kner (1860: 10) as Chalceus opalinus . This specimen (NMW 16396) was collected by J. Natterer at “Irisanga” (Rio Orissanga at Orissanga, now Estiva Gerbi, a tributary of rio Mogi-Guaçu, upper rio Paraná basin, São Paulo state; cf. Vanzolini, 1993). Kner (1860: 10) noticed that this specimen, in constrast with Cuvier’s (1819) description of Chalceus opalinus , possessed a conspicuous caudal peduncle blotch. This latter character was in fact the one used by Günther (1864), who has not examined Kner’s (1860) specimen, to diagnose it from Chalceus opalinus (“coloration uniform, without blotchess” versus “a large black blotch at the base of the caudal fin”; Günther, 1864: 334). Brycon nattereri possess, in fact, a caudal peduncle blotch considerably more conspicuous than the one found in B. opalinus , though there are some variation in this character (see item “Variation”, above). More importanly is the black pigmentation extending into the caudal-fin rays, a condition that clearly diagnoses Brycon nattereri from B. opalinus and, in fact, from all remaining, similar-looking Brycon species from eastern Brazil.

Brycon reinhardti was described by Lütken (1875a: 134–135) for the rio das Velhas, a tributary of the rio São Francisco, Brazil. A little later, the same author provided a more detailed description, comparing it solely with the sympatric Brycon lundii (= B. orthotaenia ) ( Lütken, 1875b: 221–223; 2001: 111–113). Lütken (1875b: 134; 2001: 111) mentioned that the syntypical series of the species was composed by 10 specimens. Lima (2003: 177) listed ten syntypes, distributed in several ichthyological colllections (SMNS, BMNH, ZMUC, MNHN, ZMB, NMW). We have examined five syntypes (MNHN 9589, one syntype; BMNH 1876.1.10.36, one syntype; NMW 59761, two syntypes; USNM 44955, one syntype). The last specimen, though not listed by Lima (2003), undoubtedly also belongs to the syntypical series, which makes the syntypes of Brycon reinhardti to number eleven, instead of ten. As noticed under the item “Variation”, above, there are no differences among Brycon nattereri populations from the rio São Francisco and upper rio Paraná basins, and consequently we consider Brycon reinhardti as a synonym of the latter.

Material examined. Type material. NMW 16396 (1, 243.0 mm SL): " Irisanga " [= Brazil, São Paulo, Oriçanga (now Estiva Gerbi, 22°16’S, 46°57’W), rio Grande basin]; J. Natterer, no date (1822–1823) Holotype of Brycon nattereri Günther . MNHN 9589 (1, 130.2 mm SL); NMW 59761 (2, 115.9–192.0 mm SL); BMNH 1876.1.10.36 (1, 154.6 mm SL); USNM 44955 (1, 125.4 mm SL): “ Rio das Velhas ” [trib. Rio São Francisco , Minas Gerais, Brazil]. J.T. Reinhardt; syntypes of Brycon reinhardti Lütken.

Non types. Brazil, upper rio Paraná basin , Goiás: MZUSP 58850 (1, 154.2 mm SL): Itumirim, rio Corrente, trib. rio Paranaíba , c. 18°30’53’’S, 52°5’25’’W; J.C. Garavello & M.L. Mussara, 28 Nov–1 Dec 1994. MZUSP 43132 (1, 150.0 mm SL): Quirinópolis, rio Paranaíba system, c. 18°34’S, 50°26’W, collector and date not specifed . MNRJ 19895 (2, 172.7– 196.5 mm SL): Catalão, córrego da Prata, trib. rio São Marcos, rio Paranaíba basin, 17°47'24''S, 47°35'46''W; F. A. Bockmann et al., 21 Nov 1999 . MNRJ 19771 (1, 139.3 mm SL); MNRJ 19772 (1, 146.0 mm SL): Catalão, ribeirão São Domingos, trib. rio São Marcos , rio Paranaíba basin, 18°5'45''S, 47°42'10''W; F. A. Bockmann et al., 24 Sept 1999 . MNRJ 19893 (1, 125.4 mm SL); MNRJ 19892 (5, 69.9–97.7 mm SL): Catalão, córrego da Anta Gorda, trib. rio São Marcos, fazenda Barreiro , 17°52'34''S, 47°35'46''W ; F. A. Bockmann et al., 20 Nov 1999. MNRJ 19894 (1, 157.3 mm SL): Catalão, ribeirão Pires, trib. rio São Marcos , rio Paranaíba basin, 17°52'23''S, 47°43'45''W ; F. A. Bockmann et al., 20 Nov 1999. MNRJ 19719 (1, 50.9 mm SL) ; MNRJ 19720 (1, 56.9 mm SL): Catalão, rio São Marcos, trib. rio Paranaíba , bridge at road GO-506, Porto Carapina; C . A. Figueiredo et al., 22 Sept 1999. MNRJ 19710 (1, 39.0 mm SL): Catalão, córrego do Barreiro, trib. rio São Marcos , rio Paranaíba basin; C . A. Figueiredo et al., 24 Sept 1999. MNRJ 19891 (3, 22.0– 23.2 mm SL): Catalão, ribeirão Buracão, trib. rio São Marcos , rio Paranaíba basin; F . A. Bockmann et al., 17 Nov 1999 . ZUEC 6364 (1, 132.1 mm SL): Davinópolis, rio São Bento (trib. Rio São Marcos), 18°8’7’’S, 47°38’24’’W ; T.C. Pessali, May 2010. MZUSP 51053 (3, 1 cs, 146.7–212.6 mm SL); MZUSP 68520 (1, 238.9 mm SL): Caldas Novas, rio Sapé, trib. rio Corumbá, rio Paranaíba basin, 17°48’S, 48°35' W ; NUPÉLIA, 23–24 March 1996. NUP 1304 (1, 242.7 mm SL): Caldas Novas, rio Corumbá, trib. rio Paranaíba , 17°43'37''S, 48°32'54''W ; NUPÉLIA, 9 Apr 1999. MZUSP 104339 (2, 98.6–117.3 mm SL): Corumbaíba, córrego Libório, trib. rio Corumbá , 17°55'48"S, 48°28'58"W ; NUPÉLIA, 21 March 1996. MZUSP 79967 (1, 126.6 mm SL): Luziânia, córrego Raso , trib. Rio Corumbá, 16°19’28’’S, 48°11’43’’W ; H.L.R. Silva, no date. Distrito Federal: MNRJ 11265 (1, 114.7 mm SL): Brasília, rio Gama ( rio São Bartolomeu basin), c. 15°54’S, 47°54’W ; L.O. Soares, 1957. MZUSP 19861 (18, 19.3–26.4 mm SL); MZUSP 51007 (4, 17.6–25.6 mm SL): Planaltina, rio Piriripau ( rio São Bartolomeu basin), c. 15°41’S, 47°39’W ; Expedition MZUSP/USNM, 30 Sept 1977. IBGE uncat. (1, 300.3 mm SL): Brasília, Ribeirão Santa Maria, Lago de Santa Maria, Parque Nacional de Brasília, 15°41’2’’S, 48°1’17’’W; M.C.L. Ribeiro et al., 26 Aug 1994. IBGE uncat. (1, 111.8 mm SL): Brasília, córrego Três Barras, trib. Ribeirão Bananal, Parque Nacional de Brasília, 15°39’48’’S, 47°57’21’’W; M.C.L. Ribeiro et al., 19 Oct 1992. Minas Gerais: MZUSP 59002 (1, 140.1 mm SL): Uberlândia, rio Araguari, immediately downstream Miranda hydroelectric dam, 18°54’S, 48°2’W; V. Vono, Aug 1997 . MZUSP 58910 (1, 206.9 mm SL): Nova Ponte, rio Araguari, Nova Ponte dam, c. 19°7’S, 47°36’W; F. Vieira et al., Feb 1994 . MZUSP 59003 (1, 208.7 mm SL): Uberlândia, rio Araguari , UHE Miranda dam, c. 18°54’S, 48°2’W; V. Vono, May 1998 . ZUEC 7940 (4, 98.6–106.7 mm SL): Veríssimo, rio Uberaba (trib. Rio Grande), 19°41’46’’S, 48°11’30’’W; D.C. Ribeiro & J.M . A. Chagas, 29 Sept 2012. MZUSP 44947 (2, 261.5– 283.3 mm SL): Sacramento, rio Araguari, trib. rio Paranaíba , c. 19°46’S, 47°20’W ; E. Zaniboni-Filho, 23–27 Sept 1991. MZUSP 45793 (2, 168.1–238.0 mm SL): Desemboque, rio das Velhas ou Araguari , 20°0’S, 47°1’W ; A. L. Silva, July 1993 . MZUSP 17834 (1, 52.9 mm SL): ribeirão da Prata, road São João Del Rei/ Itutinga , c. 21°13’S, 44°22’W ; H. A. Britski & J.C. Garavello, 10 Nov 1969. MZUSP 51526 (2, 199.8– 216.7 mm SL): Baependi, rio Itaúna, Pedra Branca , c. 21°57’S, 44°51’W ; M. A.F. Filho, 9 Feb 1996. LBP 8101 (1, 236.0 mm SL): Carrancas, rio Capivari , c. 21°32’S, 44°42’W ; C. Oliveira et al., 18 May 2009. São Paulo: MZUSP 3359 (1, 99.6 mm SL): Monte Alegre do Sul, rio Camanducaia , c. 22°42’S, 46°40’W ; J. Lima, 1943 . CAS 79218 (1, 204.2 mm CP), Itatiba [Rio Atibaia at Itatiba , c. 22°58’S, 46°50’W] ; J. Lima, 1907. MNRJ 20159 (4, 68.3–92.1 mm SL): Itararé, rio Verde road SP-258, Itararé / Itapeva border, 24°5’2’’S, 49°12’2’’W ; P. A. Buckup & M.R.S.Melo, 25 Jan 2000 . Paraná: MZUEL 826 (2, 222.9–253.0 mm SL): Tibagí, Guartelá Ecological State Reserve, rio Iapó (trib. rio Tibagí ), c. 24°32’S, 50°17’W ; O. A. Shibatta et al., 1 Nov 1996. MZUEL 5746 (2, 190.0–230.0 mm SL): Santa Amélia, ribeirão Laranjinha (trib. rio das Cinzas), 23°17’52’’S, 50°28’43’’W ; B. Galindo et al., 27 Feb 2011. NUP 8534 (1, 151.0 mm SL): Turvo, rio Pedrinho, trib. rio Ivaí , 25°4’S, 51°30’W ; D. Viana, 20 Jan 2009. Rio São Francisco basin , Minas Gerais: MZUSP 58949 (2, 191.4– 238.4 mm SL): Jaboticatubas / Santana do Riacho, rio Cipó (trib. Rio das Velhas), Serra do Cipó National Park , c. 19°20’S, 43°38’W; F. Vieira et al., 31 May 1994 . MZUSP 58948 (1, 111.7 mm SL): Jaboticatubas / Santana do Riacho, rio Cipó (trib. Rio das Velhas), Serra do Cipó National Park , c.

19°20’S, 43°38’W; F. Vieira et al., 15 March 1994. MZUSP 58950 (1, 244.7 mm SL): Jaboticatubas / Santana do Riacho, rio Cipó (trib. Rio das Velhas), Serra do Cipó National Park , c. 19°20’S, 43°38’W; F. Vieira et al., 30 Nov 1994 . MZUSP 51052 (1, 228.4 mm SL): Jaboticatubas / Santana do Riacho, rio Cipó (trib. Rio das Velhas), Serra do Cipó National Park , c. 19°20’S, 43°38’W; F. Vieira et al., Aug 1991 . MZUSP 1599 (1, 217.0 mm SL): Lassance, ribeirão São José (trib. Rio das Velhas), Serra do Cabral , c. 17°54’S, 44°31’W; E. Garbe, 1912 . MNRJ 11264 (1, 64.0 mm SL): Pirapora , córrego da Cachoeira, c. 17°20’S, 44°59’W; G.S. Myers, P.M. Ribeiro & A.L. Carvalho, Oct 1942 . ZUEC 6383 (2, 51.8–63.5 mm SL): Buritizeiro, ribeirão das Gaitas, trib. rio do Sono , 17°17’43’’S, 45°18’50’’W; T.C. Pessali & T. A. Barroso, Nov 2011 . MZUSP 17019 (1, 122.5 mm SL): Buritis , ribeirão dos Confins (trib. Rio Urucuia), 15°38’S, 46°22’W; P.E. Vanzolini, Oct 1964 . UFRGS 11266 (5, 54.6–67.7 mm SL): Unaí / Palmeirinha, trib. rio Salobro at road Unaí / Palmeirinha , 16°09’24’’S 46°44’48’’W, G. Frainer, F.R. Carvalho & V. A. Bertaco, 11 Sept 2009 . Rio Tocantins basin , Goiás: MZUSP 113836 (1, 75.3 mm SL): Goiás, São João da Aliança , ribeirão das Brancas, road GO-118, 14°36'56.89"S 47°29'55.94"W; F. Dagosta et al., 27 Nov 2013 . MZUSP 113865 (7, 94.4–115.5 mm SL): Teresina de Goiás, rio das Pedras, Cachoeira do Poço Encantado , 13°52'28.90"S, 47°15'45.20"W; F. Dagosta et al., 29 Nov 2013 . MZUSP 113885 (3, 79.4–146.5 mm SL): São Jorge, rio São Miguel, at meeting with rio Segredo , 14°8'15.00"S 47°39'58.00"W; F. Dagosta et al., 28 Nov 2013 . MZUEL 5745 (4, 19.6–32.0 mm SL): Pirenópolis, ribeirão Santa Maria (trib. rio das Almas), 15°50’50’’S, 48°55’8’’W; O . A. Shibatta & A. Claro, 15 Jul 2010. MNRJ 13069 (1, 89.2 mm SL): Cavalcante, córrego São Bento, trib . rio Preto (trib. rio Tocantinzinho ); D.F. Moraes Jr., 9 Dec 1987 . MCP 23938 (6, 22.2—34.0 mm SL): Cavalcante, córrego Móquem, road Colinas/Cavalcante, 13°56'28'’S, 47°42'31'’W; W.R. Koch et al., 5 Aug 1996. CAS 68822 (2, 197.3– 235.6 mm SL): Córrego do Poichos into R. Maranhão; C. Ternetz, 10 Nov 1923. CAS 68828 (1, 113.2 mm SL) ; CAS 68828 (2, 172.1– 232.2 mm SL): córrego do Monjolo into rio Maranhão into rio Tocantins; C. Ternetz, 1–14 Oct 1923 . CAS 68831 (3, 126.8–214.0 mm SL): Córrego dos Bichos into R. Mangabeira into R. Maranhão; C. Ternetz, 14 Nov 1923. MZUSP 95051 (1, 83.4 mm SL): Minaçu, trib . Rio Tocantizinho, near Serra da Mesa dam, 14°8’46’’S, 48°2’52’’W; O.T. Oyakawa & K.C. Mautari, March 2006 . MZUSP 62268 (2, 57.7–68.9 mm SL): Minaçú, trib. rio Tocantizinho , 14°04’43’’S, 48°12’49’’W; M.T. Rodrigues et al., 19 Dec 1995 . MZUSP 59623 (3, 1 cs, 84.1–144.6 mm SL): Minaçú, trib. rio Tocantizinho , 14°02'27''S, 48°12'22'' W; M.T. Rodrigues et al., 20 Dec 1995 . MZUSP 104124 (1, 212.0 mm SL); MZUSP 104223 (1, 179.4 mm SL): Minaçú, rio Tocantizinho , 14°12’44’’S, 48°3’24’’W; D.F. Moraes & D. A. Halboth, 9–16 Dec 1995 . MZUSP 104125 (4, 98.4– 220.2 mm SL): Minaçú, rio Tocantizinho , 14°12’44’’S, 48°3’24’’W; D.F. Moraes & D. A. Halboth, 17 Apr 1996 . MZUSP 103126 (4, 125.7– 206.4 mm SL): Minaçú, rio Tocantizinho , 14°12’44’’S, 48°3’24’’W; D.F. Moraes & D . A. Halboth, 11 Aug 1996. MZUSP 104222 (1, 204.3 mm SL): rio Tocantizinho, mouth of rio Palmeirinha , 14°3’57’’S, 48°29’37’’W; D.F. Moraes & D . A. Halboth, 16 Feb 1995 . Distrito Federal: IBGE uncat. (4, 94.0– 187.0 mm SL): Brasília, Ribeirão Palmeiras, trib . rio Maranhão, 15°31’10’’S, 47°43’40’’W; M.C.L. Ribeiro et al., 8 Jul 1998 . IBGE uncat. (2, 138.0–165.0 mm SL): Brasília, Córrego Monjolo , trib. rio da Palma (trib. rio Maranhão), 15°31’9’’S, 47°58’9’’W; M.C.L. Ribeiro et al., 23 Jul 1998 . IBGE uncat. (10, 85.0–173.0 mm SL): Brasília, Ribeirão Dois Irmãos, trib. rio do Sal (trib. rio Maranhão), 15°31’9’’S, 48°6’56’’W; M.C.L. Ribeiro et al., 12 Aug 1998 .

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 6. Diagrammatic representation of the head profile, maxillary and infraorbitals showing the distinct morphologies found among cis-andean Brycon species, represented by selected species. A. Brycon amazonicus, MZUSP 3815, 152.3 mm SL. B. Brycon insignis, MCZ 21112, 232.2 mm SL. C. Brycon dulcis, MZUSP 1531, 146.6 mm SL. D. Brycon falcatus, MZUSP 3845, 195.1 mm SL. E. Brycon opalinus, MCZ 21123, 210.5 mm SL. F. Brycon orbignyanus, MZUSP 3900, 108.9 mm HL. G. Brycon ferox, MCZ 60934, 310.3 mm SL. H. Brycon orthotaenia, MZUSP 2007, 188.7 mm SL. I. Brycon polylepis, MZUSP 70413, 203.9 mm SL. J. Brycon stolzmanni, UMMZ 185306, 120.0 mm SL.

FIGURE 43. Map of central and eastern Brazil, showing known localities of Brycon opalinus (black dots), and B. nattereri (red dots).

FIGURE 44. Brycon nattereri, NMW 59761, 192.0 mm SL: Brazil, Minas Gerais, rio das Velhas. Syntype of Brycon reinhardtii Lütken.

FIGURE 45. Brycon nattereri, MZUSP 45793, 238.0 mm SL: Brazil, Minas Gerais, rio Araguari.

FIGURE 46. Brycon nattereri, MZUSP 59003, 208.7 mm SL: Brazil, Minas Gerais, rio Araguari.

FIGURE 47. Brycon nattereri, MNRJ 19895, 172.7 mm SL: Brazil, Goiás, córrego da Prata.

FIGURE 48. Brycon nattereri, MZUSP 58950, 244.7 mm SL: Brazil, Minas Gerais, rio Cipó.

Tables

TABLE 13. Morphometric data of Brycon nattereri (A: holotype, NMW 16396; B: syntypes of Brycon reinhardti: MNHN 9589; NMW 59761 (2); BMNH 1876.1. 10.36 (1); USNM 44955 (1). Mean and range does not include holotype (which is a stuffed specimen).

	A	B	n	Range	Mean
Standard length (SL)	243.0	115.9–192.0	73	52.9–283.3	-
Percentages of standard length
Depth at dorsal-fin origin	28.9	25.4–29.0	68	22.6–32.5	27.6
Snout to dorsal-fin origin	52.1	52.7–55.8	73	50.6–58.7	53.8
Dorsal-fin base length	11.3	9.8–13.2	73	9.5–13.2	11.1
Posterior terminus of dorsal fin to adipose fin	23.9	21.8–24.0	73	20.1–25.5	22.6
Posterior terminus of dorsal fin to hypural joint	37.6	33.7–38.6	72	30.8–38.6	35.3
Snout to pelvic-fin insertion	46.6	48.8–52.2	64	47.3–55.0	51.2
Snout to anal-fin origin	66.0	67.6–70.7	72	60.9–73.6	68.5
Anal-fin base length	20.3	19.1–21.4	73	16.5–23.1	20.0
Caudal peduncle length	13.5	13.3–16.2	73	12.8–19.2	15.8
Dorsal-fin height	16.3	18.2–20.9	71	15.5–22.8	18.7
Pectoral-fin length	14.8	16.8–18.2	73	14.5–20.5	17.5
Pelvic-fin length	11.9	14.4–16.2	71	9.4–16.2	14.1
Caudal peduncle depth	10.1	8.5–9.8	72	8.1–10.6	9.3
Head length	21.9	23.8–28.5	73	22.7–32.0	27.0
Percentages of head length
Head height	78.6	66.1–71.5	73	61.2–78.6	71.3
Snout length	27.6	27.6–30.6	73	26.1–33.4	29.3
Upper jaw length	43.8	41.7–46.5	73	36.3–46.5	44.2
Horizontal eye diameter	20.3	22.1–26.2	73	18.1–30.0	23.9
Post-orbital length	51.9	46.9–51.2	73	41.2–54.5	48.5
Least interorbital width	37.0	29.1–37.4	73	24.8–41.3	33.4