Brycon gouldingi Lima, 2004

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 : 129-133

Brycon gouldingi Lima, 2004

( Figs. 75–77 ).

Brycon sp.: Santos et al., 1984: 42 (Lower rio Tocantins; brief description, diet).

Brycon cf. cephalus: Tejerina-Garro et al., 1998: 402 (Goiás, São Miguel do Araguaia, marginal lakes of the rio Araguaia; relative abundance).

Brycon gouldingi Lima, 2004: 279 –287 (description; type-locality, “ Brazil; Pará; Parauapebas, Igarapé da Boa Vista, tributary of rio Itacaiúnas, Serra dos Carajás c. 5°52’S, 50°29’W ”); Albrecht et al., 2009: 181 –191 ( Serra da Mesa dam, upper rio Tocantins basin, Brazil; weight-length relationships, reproduction, diet, persistence in the reservoir); Caramaschi et al., 2012: 49 ( Brazil, Goiás, Serra da Mesa dam; abundance); Bartolette et al., 2012: 61 ( Brazil, Goiás, Serra da Mesa dam); Albrecht et al., 2012: 205 ( Brazil, Goiás, Serra da Mesa dam; trophic analysis); Pelicice & Agostinho , 2012: 711 ( Brazil Tocantins, Peixe Angical dam fish ladder); Faustino et al., 2015: 1491 –1496 (early development of embryos and larvae).

Brycon falcatus (not Muller & Troschel): Santos et al., 2004: 55 (photograph; rio Tocantins at Tucuruí dam, Pará, Brazil).

Brycon amazonicus (not Agassiz, in Spix & Agassiz): Mérona et al., 2010: 106, 194 (Lower rio Tocantins, Pará; abundance, impacts of Tucuruí dam).

Brycon af. melanopterus (sic) (not Cope): Iglesias-Rios, 2012: 326 (Brazil, Goiás, Serra da Mesa dam: impacts of damming)

Diagnosis. Brycon gouldingi is distinguished from all its congeners, except B. falcatus , B. melanopterus , B. whitei , B. orbygnianus , B. orthotaenia , B. hilarii , and B. amazonicus 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 gouldingi 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 B. gouldingi is B. amazonicus , from which it can be distinguished by the presence of a distinct crescent- or V-shaped blotch on the caudal peduncle and caudal fin (vs. dark pigment on the caudal peduncle and caudal fin diffuse, never crescent- or V-shaped). See the item “Comparisons” on Brycon amazonicus for more information on the diagnosis of both species.

Description. Morphometric data are presented in Table 19 . One of the largest species in the genus, largest specimen examined reaching 477.9 mm SL. Body moderately slender, moderately high in specimens above 300 mm SL. Largest body height at dorsal-fin level. Dorsal body profile slightly convex from upper lip margin to vertical through anterior naris, straight to slightly concave from this point to supraoccipital tip, moderately convex from this point to dorsal-fin origin, straight along dorsal-fin base, slightly convex from dorsal-fin terminus 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. Maxilla extending posteriorly to vertical slightly anterior to middle of pupil. Adipose eyelid well developed. Premaxillary teeth in three rows; teeth of third row largest. Nine (9), 10 (11), 11 (11), 12 (13), or 13 (5) tricuspidate teeth in outer series. Four (11), 5 (30), or 6 (7) trito pentacuspidate teeth in second, inner premaxillary row, plus 3 (2), 4 (40), or 5 (6) tricuspidate teeth between the first and third rows. Two (3 in one specimen) teeth in third premaxillary row, medial teeth largest, pentacuspidate, symphyseal teeth smaller, tri- to pentacuspidate. Maxillary margin approximately straight, except for slight convexity in its distal extremity. Eleven to 21 maxillary teeth, slightly smaller than teeth of first premaxillary row, anterior teeth tricuspidate, posterior teeth unicuspidate. Dentary with 8 (1), 9 (9), 10 (7), 11 (1), or 12 (2) teeth in main series. Anterior four dentary teeth assymetrical, considerably larger and bulkier than remaining teeth, pentacuspidate, each with central cusp distinctly larger than remaining cusps. Remaining dentary teeth progressivelly smaller, penta-, tri- to unicuspidate. Inner (lingual) series consisting of a single symphyseal tooth, considerably smaller than teeth of main series anterior to it, plus row of 15 small, unicuspidate teeth, originating at level of 6th tooth of main series.

Scales cycloid. Lateral line complete, from supracleithrum to caudal-fin base. Sixth-six (1), 69 (1), 71 (1), 72 (4), 73 (5), 74 (8), 75 (5), 76 (7), 77 (5), 78 (5), 79 (2), 80 (3), 81 (1), or 82 (1) scales in lateral line series; laterosensory tube ramified, each lateral line scale with two to three branchs in the smallest specimen examined (MZUSP 18196, 118.5 mm SL), gradually becoming more complex during ontogeny, up to the development of ascendent and descendent main branches, and about 6 to 10 secondary branches in specimens larger than 300 mm SL. Horizontal scale rows between dorsal-fin origin and lateral line 13 (6), 14 (24), 15 (14), or 16 (3). Horizontal scale rows between lateral line and pelvic-fin insertion 7 (2), 8 (17), 9 (22), or 10 (6). Circumpeduncular scales 20 (2), 21 (3), 22 (20), 23 (19), 24 (3), or 25 (1).

Dorsal-fin rays ii, 9. Dorsal fin origin approximatelly at middle of SL. First dorsal-fin pterygiophore inserting behind neural spine of 14th vertebra. Anal-fin rays iii (not including first, small unbranched ray only visible in the cs specimen), 18 (1), 19 (1), 20 (2), 21 (4), 22 (16), 23 (13), or 24 (10). First anal-fin pterygiophore inserting behind haemal spine of 28th vertebra. Pectoral-fin rays i, 12 (4), 13 (22), 14 (20), or 15 (2); pelvic-fin rays i,6 (3), 7 (43), or 8 (2); main caudal-fin rays 10/9. Last unbranched and anterior 2–3 anal-fin rays longer, remaining rays progressively shorter towards anal-fin end. Anal fin presenting small hooks on posterior branch of branched rays in one specimen (MZUSP 70420). Sheath of scales composed of 4 to 5 horizontal series, covering basal third of analfin rays. Caudal fin forked, lobes slightly emarginated.

Four branchiostegal rays. First gill arch with 15 (3), 16 (3) or 17 (3) lower gill rakers, 16 (2), 17 (5), or 18 (2) upper gill rakers and 1 at angle. Vertebrae 47 (1). Supraneurals 10 (1).

Coloration in alcohol. Overall color pattern of specimens still retaining guanin light gray dorsally, with silvery hue. Top of head and snout dark gray; infraorbitals and opercle silvery. Maxilla, gular area, and dentary light brown. Dorsolateral body surfaces silvery to coppery, dark brown dorsally, becoming gradually clear ventrally. Humeral blotch present, oval, horizontally elongated, formed by subjacent pigment, lying above lateral line, at level of second to fourth scales. Longitudinal stripes extending all along the trunk, wavy, formed by dark pigment concentrated on upper and lower scale margins in dorsolateral surfaces of body. Relatively faint, rounded dark area on caudal peduncle. Caudal pigmentation contiguous with caudal peduncle blotch, occupying most of caudal fin except for distal margin and two dorsalmost and two ventralmost principal rays. Contour of blotch formed by dark pigmentantion on caudal peduncle and caudal fin crescent or V-shaped. Moderate to heavy darkly pigment on pectoral fins, pigmentation mainly concentrated on outermost seven to eight rays. Pelvic fins pale to intensely dark. Intense dark pigmentation on anal-fin interradial membranes, mainly on posteriormost rays. Dorsal fin pale, with some dark pigmentation on interradial membranes. Adipose fin dark gray. Specimens which lost guanine as a result of long storage in formalin with overall color pattern brownish, without silvery hues on dorsolateral surfaces of body, infraorbitals, or opercle, and with longitudinal stripes more evident.

Color in life. Description based on slides taken by Carlos Figueiredo from two individuals collected in the rio Tocantizinho basin, upper rio Tocantins, in the region of the present Serra da Mesa dam, and from specimens collected by J.B. Nunes in the rio Araguaia system. Dorsum bluish-gray; top of head and snout dark gray; sides of body, opercle and infraorbitals pale, with metallic hue; humeral blotch and wavy dark stripes on sides of body clearly visible; pectoral fin darkened; crescent-shaped black blotch on caudal peduncle and caudal fin conspicuous. Dorsal and adipose fins reddish, pelvic and anal fins yellowish, with a tenuous, dark basal stripe.

Common names. Matrinchã, piabanha ( Santos et al., 1984: 42) .

Distribution. Endemic from the rio Tocantins basin, where it is widespread in the main river systems: the rio Tocantins itself, rio Araguaia, rio das Mortes, rio Paranã, and rio Itacaiúnas, Brazil ( Fig. 74 ). In the last few years, Brycon gouldingi has been stocked outside its native range, and escaped specimens were reported from the rio São Francisco in Pernambuco (J.M. Barbosa, pers. comm..). Mauro C. Lopes (pers. comm..) photographed a juvenile of the species fished at the rio Xingu in the Parque Indígena do Xingu, Mato Grosso, in 2008. Since extensive collecting activities just above the park, in the rio Culuene, revealed only Brycon falcatus (pers. obs.), it is suspected that this record might be the result of released specimens collected from the neighbouring rio Araguaia basin. At least one rancher at the upper rio Xingu basin was known to stock fishes from the rio Araguaia system. These fishes were released into the rio Suiá-Missu (a tributary of the upper rio Xingu) when the dam where they were stocked burst after major rains (Lício Moraes, pers. comm.). There are still no evidence of established populations outside the natural area of distribution.

Ecological notes. Diet mentioned as being composed of fruits and insects ( Santos et al., 1984: 42).

Examination of the stomach contents of one specimen (MZUSP 18069, 161.3 mm SL), revealed mainly pieces of fruits and crushed seeds, but also a small cockroach and an ant. Albrecht et al. (2009), in a detailed analysis of the diet of the species at Serra da Mesa dam, found, in order of importance, seeds and fruits, terrestrial invertebrates, and fishes as the most important dietary itens for the species. James B. Nunes (pers. comm.) reported that the species undertakes massive migrations in the area of Ilha do Bananal, middle rio Araguaia basin. Brycon gouldingi leave the floodplains at the end of the rainy season in mixed schools with Prochilodus nigricans and Leporinus trifasciatus . Breeding schools are observed during the rainy season, between December and March.

Conservation. The rio Tocantins basin is progressively being dammed, with five major hydroelectric dams already in operation (Tucuruí, Estreito, Lajeado, Peixe/Angical, and Serra da Mesa) and a few more being planned. It is expected that, as a presumable long-range total spawner, Brycon gouldingi populations will be severely impacted by these dams. Prospects on the rio Araguaia are a litlle better, since not much hydroelectric development is expected in that river basin due to its general low gradient. Overall, the conservation status of Brycon gouldingi give some causes to concern as long as developmental plans for the Araguaia/ Tocantins basin by the Brazilian government remain unabated.

Material examined. Type material. Holotype: MZUSP 61400 (1, 374.7 mm SL): Brazil; Pará; Parauapebas, Igarapé da Boa Vista , tributary of rio Itacaiúnas , Serra dos Carajás c. 5°52’S, 50°29’W; M. Goulding, Nov 1983 . Paratypes: Brazil, Pará: MZUSP 56808 (3, 214.8– 237.2 mm SL) ; MZUSP 56948 (1, 262.3 mm SL): Parauapebas, Serra dos Carajás, rio Itacaiúnas; Caldeirão , c. 5°52’S, 50°29’W; M. Goulding, April 1983 . MZUSP 56949 (3, 313.4– 365.9 mm SL): Parauapebas, igarapé do Cinzento, rio Itacaiúnas , c. 5°51’S, 50°32’W; M. Goulding, Nov 1983 . MZUSP 58044 (1, 224.4 mm SL): Parauapebas, igarapé Salobo, tributary of rio Itacaiúnas , 5°46’50’’S 50°32’48’’W; P.S. Pompeu, July 1997 . MZUSP 57033 (28, 199.7–298.0 mm SL); MCP 34184 (1, 223.5 mm SL); FMNH 112957 (1, 218.0 mm SL); USNM 374028 (1, 220.7 mm SL): Parauapebas, rio Itacaiúnas, Caldeirão , c. 5°52’S, 50°29’W; M. Goulding, April / May 1983 .; MZUSP 61399 (1, 353.9 mm SL): Parauapebas, Igarapé Águas Claras , Serra dos Carajás, c. 5°52’S, 50°29’W; M. Goulding, Nov 1983 . MZUSP 31449 (1, 345.1 mm SL): Parauapebas, rio Itacaiúnas , Serra dos Carajás, c. 5°52’S, 50°29’W; M. Goulding, Nov 1983 . MZUSP 18100 (1, 161.5 mm SL): marginal lake from igarapé Espírito Santo, between Baião and Tucuruí , rio Tocantins; EPA, 11 Sept 1970 . MZUSP 18090 (1, 231.2 mm SL): Baião , rio Tocantins, c. 2°48’S, 49°41’W; EPA, 9–10 Sept 1970 . MZUSP 18078 (2, 152.5– 186.5 mm SL): igarapé do Limão, near Baião , rio Tocantins, c. 2°48’S, 49°41’W; EPA, 9 Sept 1970 . MZUSP 18050 (1, 192.0 mm SL): Paraná Samuuma, mouth of Tocantins, c. 1°56’S, 49°12’W; EPA, 4 Sept 1970 . MZUSP 18196 (1, 118.5 mm SL): igarapé dos 5, km 5 from the road Tucuruí-Mato Grosso , c. 3°42’S, 49°27’W; EPA, 22 Sept 1970 . MZUSP 18069 (2, 1 cs, 161.3–198.9 mm SL): Mocajuba, igarapé Oxipucu , rio Tocantins, 2°34’S, 49°31’W; EPA, 8 Sept 1970 . INPA 16370 (1, 226.2 mm SL): rio Tocantins, Tucuruí fish market, c. 3°42’S, 49°27’W; Eq. Ictiologia / INPA, 27 June 1982 . INPA 16367 (1, 121.0 mm SL): rio Tocantins, igarapé Vermelho, 0.5 hour above its mouth, Itupiranga , c. 5°09’S, 49°20’W; Eq. Ictiologia / INPA, 2 July 1982 . INPA 16393 (1, 107.7 mm SL): Acarí Pucú , rio Tocantins, 2°42’S, 49°43’W; Eq. Ictiologia / INPA, 27 March 1982 . INPA 16379 (1, 210.7 mm SL): rio Tocantins, Tucuruí , c. 3°42’S, 49°27’W; Eq. Ictiologia / INPA, 26 Oct 1980 . INPA 16376 (3, 158.1– 184.4 mm SL): rio Tocantins, Itupiranga , c. 5°09’S, 49°20’W; Eq. Ictiologia / INPA, 6 July 1980 . INPA 16247 (1, 289.0 mm SL): rio Tocantins, Itupiranga , Ressaca dos Macacos, c. 5°09’S, 49°20’W; Eq. Ictiologia / INPA, 3 July 1982 .

Non types. Brazil, Tocantins: UNT 2197 (1, 477.9 mm SL): Peixe, rio Santa Tereza , c. 11°47’S, 48°38’W ; NEAMB, 12 March 2001. UNT 3442 (2, 92.3–116.2 mm SL); UNT 3440 (1, 136.8 mm SL); UNT 3517 (1, 244.0 mm SL): Porto Nacional , rio Tocantins, c. 10°42’S, 48°25’W ; NEAMB, Feb–April 2002. INPA 20117 (1, 254.8 mm SL): Caseara, rio Araguaia , Lago Volta Grande, P.E. Cantão, 9o47’19” S, 50o 9’53” W; J. Zuanon et al., 19 May 2000 . INPA 20490 (1, 359.0 mm SL): Caseara, lago Paredão, P.E. Cantão, 9o22’40” S, 49o58’32” W; J. Zuanon et al., 19 Feb 2000. Goiás: MZUSP 44572 (1, 382.2 mm SL): Monte Alegre de Goiás, rio Paranã, above mouth of rio Bezerra , c. 13°16’S, 47°31’W; J.C. Oliveira & W.J. E.M . Costa, 10–13 Jan 1989 . MZUSP 70423 (1, 283.8 mm SL): rio Tocantins, below Serra da Mesa dam, 13°49'55’’S, 48°17'44’’W; D.F. Moraes et al., 5 Feb 1997 . MZUSP 70422 (1, 278.2 mm SL): Serra da Mesa dam, rio Tocantizinho arm, 13°57'S, 48°15'W ; D.F. Moraes and D. A. Halboth, 6 June 1997. MZUSP 70420 (1, 328.1 mm SL): Serra da Mesa dam, rio Palmeirinha arm, 14°3'57'’S, 48°29'37'’W; D.F. Moraes and D . A. Halboth, 16 Feb 1995. MZUSP 70421 (1, 251.2 mm SL): Serra da Mesa dam, above rio Castelo Grande , 14°8'S, 48°44'W ; D.F. Moraes, 10 June 1997. MZUSP 70752 (1, 346.2 mm SL): Serra da Mesa dam, rio Tocantizinho arm, 14°00’S, 48°11’W ; D.F. Moraes and D. A. Halboth, 5 Feb 1998. MCP 17280 (1, 452, 7 mm SL): Luís Alves, marginal lagoons of the rio Araguaia , 13°14'S, 50°35'W ; F.L.T. Garro, 21 April 1994. MCZ 21126 (1, 355.0 mm SL): “Goyaz” (exact locality unknown; see Lima, 2004: 285); “Honório” [A.H. Ferreira], 1867 . Mato Grosso: MZUSP 48114 (1, 365.4 mm SL): Barra do Garças, Córrego da Ponte Queimada, c. 15°53’S, 52°15’W; W.P. Margarido, 1 Sept 1993 . MZUSP 60411 (1, 278.3 mm SL): Barra do Garças, rio Araguaia , Ouro Fino, 30 km below Barra do Garças, 15°52´03´´S, 51°58´17´´W; W. Barrella et al., 6–7 Oct 1997 .

Figures

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.

FIGURE 76. Brycon gouldingi, paratype, MZUSP 18078, 186.5 mm SL: Brazil, Pará, igarapé do Limão.

FIGURE 77. Brycon gouldingi, paratype, MZUSP 18196, 118.5 mm SL: Brazil, Pará, igarapé do 5.

Tables

TABLE 19. Morphometric data of Brycon gouldingi (A, holotype, MZUSP 61400).

	A	n	Range	Mean
Standard length (SL)	374.7	48	118.5–477.9	-
Percentages of standard length
Depth at dorsal-fin origin	33.9	46	29.0–37.3	32.7
Snout to dorsal-fin origin	49.4	48	48.9–59.3	50.2
Dorsal-fin base length	9.8	48	9.8–13.7	11.3
Posterior terminus of dorsal fin to adipose fin	25.3	48	21.8–32.8	24.7
Posterior terminus of dorsal fin to hypural joint	36.7	48	31.9–48.1	37.7
Snout to pelvic-fin insertion	46.0	47	44.5–52.8	47.4
Snout to anal-fin origin	70.4	48	64.6–77.1	68.3
Anal-fin base length	21.1	48	19.6–26.7	21.7
Caudal peduncle length	16.6	48	14.1–20.5	16.4
Dorsal-fin height	19.7	46	17.6–25.8	20.5
Pectoral-fin length	19.0	48	17.8–23.7	19.4
Pelvic-fin length	18.2	44	12.3–18.7	16.1
Caudal peduncle depth	9.3	48	8.6–11.5	9.4
Head length	22.8	48	22.5–30.2	25.2
Percentages of head length
Head height	88.2	48	77.1–92.1	82.8
Snout length	37.1	48	28.2–37.4	33.1
Upper jaw length	49.3	48	45.3–49.9	47.7
Horizontal eye diameter	21.0	48	18.7–27.9	23.8
Post-orbital length	48.6	48	42.3–52.6	47.9
Least interorbital width	51.6	48	40.0–52.6	47.0