Phenacogaster bondi Fowler, 1911: 419 Moenkhausia profunda Eigenmann, 1912 Gymnocorymbus socolofi Géry, 1964 : 25 Taxonomic revision and molecular phylogeny of Gymnocorymbus Eigenmann, 1908 (Teleostei, Characiformes, Characidae) Benine, Ricardo C. Melo, Bruno F. Castro, Ricardo M. C. Oliveira, Claudio Zootaxa 2015 3956 1 1 28 3HR9D Fowler, 1911 Fowler 1911 [151,615,1692,1718] Actinopterygii Characidae Gymnocorymbus Animalia Characiformes 9 10 Chordata species bondi    Phenacogaster bondiFowler, 1911: 419. Typelocality: “Corisal, Venezuela”.   Moenkhausia profundaEigenmann, 1912. Typelocality: “Cloaca trenches, Issorora Rubber Plantation” ( Guyana).  Gymnocorymbus socolofi Géry, 1964: 25. Typelocality: “about 200 mileseast of Bogotá, Colombia, in the upper Río Meta drainage”.   Diagnosis.  Gymnocorymbus bondiis distinguished from all congeners by the number of gill rakers on lower limb of the first branchial arch (11–12 vs. 13–16 incongeners).  Gymnocorymbus bondidiffers from  G. ternetziand G.   flaviolimaiby the number of scale rows covering the base of the anal fin (2–4 vs.5–6, respectively); by the shape of the distal margin of the anal fin (straight vs.strongly convex, respectively; Fig. 10); and by the number of pelvicfin rays (i,7 vs.i,6, respectively). It further differs from  G. ternetziby the form of the teeth in the inner premaxillary tooth row (with four to five cusps vs.three cusps, respectively; Figs. 7–8); by the overall color pattern (lack of a dense field of dark chromatophores spread homogeneously over the posterior one half of the body vs.the presence of such pigmentation, respectively) and by the shape of the first humeral mark (the presence of a wider densely pigmented region above the lateral line vs.the absence of such pigmented region, respectively; Fig. 6).   Description.Morphometric data for  Gymnocorymbus bondiare summarized in Table 3. Deep body with greatest body depth at dorsal-fin origin. Dorsal profile of head concave. Dorsal profile of body strongly convex from tip of supraoccipital spine to dorsal-fin origin. Dorsal-fin base posteroventrally slanted. Profile straight or slightly convex from posterior terminus of dorsal-fin base to end of adipose fin, and concave along caudal peduncle. Ventral profile of body convex from tip of lower jaw to anal-fin origin, anal-fin base posterodorsally slanted, and concave along caudal peduncle. Prepelvic region transversally flattened, more so proximate to pelvicfin insertion. Postpelvic region transversally flattened proximate to pelvic-fin insertion, becoming somewhat obtuse toward anal-fin origin. Supraoccipital process elongate; tip extends beyond vertical through posterior margin of opercle. Mouth terminal. Maxillar extending beyond vertical through anterior margin of orbit nearly to vertical through middle of orbit. Premaxillary teeth in two rows; outer row with four tricuspidate teeth with central cusps longest; inner tooth row with five teeth with four cusps (in the asymmetrical symphyseal tooth) or five cusps with central cusps longest. Maxillar with one pentacuspidate teeth. Dentary bearing five teeth with five cusps; central cusps usually longest, followed by one to three small teeth, with one to three cusps. Dorsal-fin rays ii,9. Pectoral-fin rays i,11 (10) or i,11,i* (67). Tip of pectoral fin extends beyond mid-length of adpressed pelvic fin. Adipose fin present. Pelvic-fin rays i,7; tip of adpressed fin reaching first branched anal-fin ray. Anal-fin rays iv,32 (15), 33* (23), 34 (21), 35 (13) or 36 (5). Caudal fin forked. Principal caudal-fin rays i,17,i. Scales cycloid. Lateral line complete, 34 (13), 35* (26) or 36 (35). Scale rows between lateral line and dorsalfin origin 7 (4), 8* (60) or 9 (9). Scale rows between lateral line and pelvic-fin origin 7 (2), 8* (62), 9 (1) or 10 (1). Scale rows around caudal peduncle 14 (2) or 15* (21). Scales in sheath along anal-fin base in 2–4 series; sheath extending posteriorly to around 27th or 28th branched anal-fin ray.   TABLE 3.Morphometric data for  Gymnocorymbus bondi; N includes type-specimens of  Phenacogaster bondi,   Moenkhausia profunda, and  Gymnocorymbus socolofi; * = holotype. N  P. bondi*  M. profunda*  G. socolofi* Range Mean Percentageof head length    Standard length (mm) 88 33.5 39.0 52.2 28.0–5 9.7 –  Percentage of standard length  Greatest depth 88 49.1 54.6 44.3 43.5–55.8 49.5  Snout to dorsal-fin origin 88 54.4 51.1 51.2 51.1–56.8 54.2  Snout to pectoral-fin origin 78 27.9 – – 26.4–32.6 29.6  Snout to pelvic-fin origin 87 47.8 46.3 43.0 42.8–49.0 47.4  Snout to anal-fin origin 87 64.9 – – 59.2–65.6 62.2  Caudal peduncle depth 88 11.4 10.9 10.9 9.5–11.8 11.0  Caudal peduncle length 88 7.7 – – 6.9–9.7 7.8  Pectoral-fin length 87 – 24.7 22.3 21.9–25.9 23.5  Pelvic-fin length 87 – – 19.6 16.5–21.0 18.5  Dorsal-fin length 87 32.8 31.3 30.4 31.2–34.6 32.8  Dorsal-fin base 88 15.0 15.2 14.9 12.8–22.5 15.8  Anal-fin length 87 20.9 19.2 17.3–22.6 19.8  Anal-fin base 88 37.0 44.6 42.7 38.9–52.7 42.5  Eye to dorsal-fin origin 87 40.0 – – 40.8–45.9 42.7  Dorsal-fin origin to caudal-fin origin 78 52.7 – – 52.1–56.7 54.5  Head length 88 28.0 26.2 26.4 24.7–29.3 27.1  Head depth 78 21.3 24.0 20.9 19.5–24.0 21.4 Snout length 85 25.8 27.6 24.6 22.7–29.6 25.2 Upper jaw length 78 37.3 – – 34.2–41.8 38.7 Horizontal orbital diameter 85 39.4 42.7 39.1 39.3–43.4 41.0 Least interorbital width 85 37.3 39.2 33.8 32-6–42.3 36.0 First gill arch with 9* (55) gill rakers on upper limb and 11* (52) or 12 (3) gill rakers on lower limb. Total vertebrae 33*, supraneurals 4 or 5* (observed in holotypevia radiograph).  Color in alcohol.Overall coloration yellow tan. Field of dark chromatophores covers both lips and dorsal over third of maxilla. Infraorbital and opercular series silvery due to the presence of guanine pigmentation. Vertical dark stripe as wide as pupil crossing the eye. Dark chromatophores more densely concentrated along entire dorsal midline. Sparse field of dark chromatophores dorsal of horizontal skeletogenous septum continuous with second humeral mark. Two conspicuous vertical dark humeral marks, anteriormost more conspicuous. Anterior humeral mark located over second to fourth lateral-line scales and extending vertically over five horizontal scale rows above and four to five horizontal scale rows below lateral line. Posterior humeral mark located over ninth to twelfth lateral line scales and extending vertically over six horizontal scale rows above and four to five horizontal scale rows below lateral line. Dorsal halves of both humeral marks wider and more densely pigmented; dorsal, anal, and caudal fins more densely pigmented along distal margins. Paired fins and caudal fin with few dark dispersed chromatophores, more so on unbranched rays. Adipose fin sparsely pigmented, more so along its dorsal border ( Fig. 10).  Sexual dimorphism.Mature males of  Gymnocorymbus bondi(LBP 2274) were identified through direct observation of their gonads. These specimens did not demonstrate small bony hooks on the anterior anal-fin rays, a secondary sexually dimorphic character often found in many species in the Characidae ( Malabarba & Weitzman 2003).The absence of bony hooks in mature males can be additionally used to diagnose  G. bondifrom all congeners.   Distribution.  Gymnocorymbus bondiis endemic from the Río Orinoco basin in Colombiaand Venezuela( Fig. 9). Phillip et al.(2013)listed  G. bondiin their checklist of fishes from Trinidad and Tobago. However, we were unable to examine those vouchers in order to confirm that report.  Moenkhausia profundawas described probably from the Aruka river, an independent river close to the border of Guyanaand Venezuela.   Remarks.Examinations of typespecimens of  Phenacogaster bondiFowler, 1911( holotype, ANSP 37863 and paratype, ANSP 37864) and  Gymnocorymbus socolofi Géry, 1964( holotype, USNM 198646) leaded Lima et al.(2003)(section of  Gymnocorymbuswritten by the first author) to conclude that they constitute the same species, and the new combination,  G. bondi(Fowler, 1911), was then formally proposed. Examination of holotypeof  Moenkhausia profunda(FMNH 53717) evidenced it is a junior synonym of  G. bondiinstead of  G. thayeri, as proposed by Géry (1972).   Material examined. Types: ANSP37863, holotypeof  Phenacogaster bondi, 33.5 mm SL, Corisal, Venezuela, 27 Feb 1911, F.E. Bond & S. Brown. ANSP37864, paratypeof  P. bondi, 29.9 mm SL, collected with the holotype. USNM198646, holotypeof  Gymnocorymbus socolofi, 52.2 mm SL, Colombia, Río Manacacias into upper Río Meta at Restrepo, circa 200 milesE of Bogotá, Jun 1963, R. Socolof. ANSP139711, paratypeof  G. socolofi, 26.1 mm SL, collected with holotype. FMNH53717, holotypeof  Moenkhausia profunda, 39.0 mm SL, Issorora rubber plantation, probably from the Aruka river, Guyana, E. S. Shideler. Non-types: 110 specimens, 84 measured (25.1–53.0 mm SL). Venezuela: ANSP141571, 25, 25.1–43.7 mm SL, Bolivar, isolated lagoon 200 yd N of Jabillal. ANSP159884, 2, not measured, caño 15.1 kmE of Río Parguaza ferry crossing on Caicara-Puerto Ayacucho highway. ANSP159885, 6, 1 c&s, 37.6-48.9 mm SL, Río Guacamayo, 100 to 600 mbelow bridge at crossing Caicara, Río Orinoco. ANSP159889, 9, 34.3–51.6 mm SL, Morichal Merecure, 3.5 kmE of Río Caura and 1.0 km N of Caicara. ANSP159890, 14, 28.5–40.8 mm SL, Bolivar, flooded pasture along Caicara -Puerto Ayacucho highway, 33 kmfrom E end of highway to Colombia. ANSP 161048, 2, not measured, Río Agua Blanca, Orinoco. ANSP165453, 22, not measured, Apure, S. Fernando Apure, flooded savannah, Río Apure, Río Orinoco. LBP 2274, 3, 29.0– 50.6 mm SL, Bolívar, Caicara del Orinoco, Río Caño (Pelo Ojo), 7°32’22.4”N 66°08’29.2”W. LBP 2281, 2, 26.5–28.5 mm SL, Bolívar, Caicara del Orinoco, Río Orinoco, 7°30’01.2”N 66°08’14.4”W. LBP 2296, 1, 32.3 mm SL, Bolívar, Caicara del Orinoco, Río Orinoco, 7°39’06.3”N 66°10’34.2”W. MZUSP96436, 3, 26.6–51.4 mm SL, Bolívar, Caicara del Orinoco, Río Orinoco, 7°32’22.2”N 66°08’29”W. FMNH 100148, 2, 40.2– 42.5 mm SL, Guárico, Río Portuguesa, Laguna Los Noreles Caño Falcón, Río Orinoco. MCZ59648, 1, 29.6 mm SL, Delta Amacuro, Río Pena. MCZ92879, 1, 32.4 mm SL, Guárico, Llanos, Caño Falcón, Río Portuguesa, Río Orinoco. USNM 260628, 8, 36.8–42.7 mm SL, Apure, Caño Caicara, where crossed by bridge on road from Montecal. Colombia: LBP 18665, 1, 38.4 mm SL, Guaviare-Meta, Río Cunimía, Río Guaviare, Río Orinoco, 3°10’30.0”N 73°39’41.0”W. LBP 18736, 2, 39.6–43.1 mm SL, Vista Hermosa-Meta, Caño Cunimia, Río Guaviare, Río Orinoco, 3°10’28.0”N73°39’43”. NRM41441, 10, 1 c&s, 31.2–53.0 mm SL, Laguna Santa Clara, tributary to Río Ocoa, ca. 5 kmS of Villavicencio, 4° 04’11.6”N73°41’38” (approximately).