CHARACIDIUM is the most speciose genus of the

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1 Two New Species of Characidium (Characiformes: Crenuchidae) from Paraguay and Xingu River Basins, State of Mato Grosso, Brazil Weferson J. da Graça 1, Carla S. Pavanelli 1, and Paulo A. Buckup 2 Copeia 2008, No. 2, Characidium nupelia, new species, is described from the upper Rio Paraguay basin, and C. xavante, new species, from the upper Rio Xingu basin, State of Mato Grosso, Brazil. The two species comprise a group diagnosed by a high number (12 18) of dark vertical bars on the body, each bar having the width of a scale. Characidium nupelia differs from C. xavante by having 12 instead of 10 scales around the caudal peduncle, a narrower interorbital distance, and a deeper caudal peduncle. Both species lack an adipose fin, have an incomplete lateral line, and have a conspicuous dark blotch on the caudal peduncle. Breeding males of the two new species present sexual hooks on some pelvic and pectoral branched fin rays. Characidium nupelia, nova espécie, é descrita da bacia do alto rio Paraguai, e C. xavante, nova espécie, da bacia do alto rio Xingu, Estado do Mato Grosso, Brasil. As duas espécies formam um grupo diagnosticado pelo elevado número (12 18) de barras verticais escuras no corpo, cada barra com a largura de uma escama. Characidium nupelia difere de C. xavante por apresentar 12 ao invés de 10 escamas circumpedunculares, distância interorbital menor e pedúnculo caudal mais alto. Ambas têm nadadeira adiposa ausente, linha lateral incompleta e uma mancha escura conspícua no pedúnculo caudal. Machos maduros das duas espécies novas apresentam ganchos sexuais em alguns raios ramificados das nadadeiras pélvica e peitoral. CHARACIDIUM is the most speciose genus of the family Crenuchidae, including 50 valid species, distributed in most freshwater drainages in tropical and subtropical areas of the Neotropical Region located between eastern Panama and La Plata, Argentina (Buckup, 2003; Taphorn et al., 2006). They are small sized fishes, which do not surpass 100 mm standard length (Buckup, 1993a). Most species possess a complete lateral line, although it is incomplete in several species. Here we describe two additional species, C. nupelia, new species, and C. xavante, new species, collected in the State of Mato Grosso, western Brazil. Both species share an incomplete lateral line and a high number (12 18) of vertical bars, each bar having the width of a scale. Characidium nupelia was collected in the region affected by the construction of the Manso Hydroelectric Reservoir in the upper Rio Paraguay basin. Characidium xavante, in turn, was collected from two small tributaries of the upper Rio Xingu basin. We also describe and illustrate presence of sexual hooks in the pectoral and pelvic fins of breeding males of both species. MATERIALS AND METHODS Institutional abbreviations follow ASIH codes listed at with the addition of LIRP (Laboratório de Ictiologia de Ribeirão Preto, FFCLRP, Universidade de São Paulo) and NUP (Coleção Ictiológica do Nupélia, Universidade Estadual de Maringá). Measurements and counts were taken with digital calipers to the nearest 0.1 mm on the left side of the specimens and follow Buckup (1993b). In the descriptions, the frequency of each count is provided in parentheses after the respective count. An asterisk indicates the count of the holotype. Thirty-seven specimens of Characidium nupelia and 30 of C. xavante were dissected (on their right side) to determine sex, which is indicated by m (male) and f (female). Observations of vertebrae, ectopterygoid teeth, branchiostegal rays, and other osteological features were based on three paratypes of Characidium nupelia and four of C. xavante that were cleared and stained (CS) according to the protocol of Taylor and Van Dyke (1985). Characidium nupelia, new species Figures 1 3, Table 1 Holotype. MZUSP 87743, 30.2 mm SL, m, Brazil, Mato Grosso, Rosário Oeste, Córrego Forquilha, tributary to Rio Manso (downstream from Manso Reservoir), upper Rio Paraguay basin, 14u449580S, 56u079390W, 24 March 2001, Nupélia. Paratypes. All from Brazil, Mato Grosso, upper Rio Paraguay basin. LIRP 5284, 10, mm SL; MNRJ 29166, 1 CS, 24.8 mm SL, f; NUP 2155, 15, mm SL: same data as holotype. MCP 23482, 6, mm SL, Arroio at Chapéu farm, Aproveitamento Múltiplo de Manso, approx. 15u289S, 55u459W, Feb. 1999, C. Strussmann. MNRJ 29164, 20, mm SL; MZUSP 87742, 20, mm SL; 1 Universidade Estadual de Maringá/Núcleo de Pesquisas em Limnologia, Ictiologia e Aqüicultura, Programa de Pós Graduação em Ecologia de Ambientes Aquáticos Continentais, Av. Colombo 5790, Maringá, Paraná, Brazil; (WJG) wefersonwjg@yahoo.com.br; and (CSP) carlasp@nupelia.uem.br. Send reprint requests to this address. 2 Museu Nacional, Departamento de Vertebrados, Quinta da Boa Vista, Rio de Janeiro, Rio de Janeiro, Brazil; buckup@acd.ufrj.br. Submitted: 11 July Accepted: 10 October Associate Editor: C. J. Ferraris. F 2008 by the American Society of Ichthyologists and Herpetologists DOI: /CI

2 Graça et al. Two new Characidium species 327 Fig. 1. Characidium nupelia, holotype, MZUSP 87743, male, 30.2 mm SL. NUP 3331, 21, mm SL: Chapada dos Guimarães, Córrego Lajinha, tributary to Rio Manso (upstream from Manso Reservoir), 14u579180S, 55u419150W, 19 July 2002, Nupélia. NUP 982, 25, mm SL; NUP 4106, 1 CS, 23.8 mm SL, m: Rosário Oeste, Córrego Forquilha, tributary to Rio Manso, 14u449580S, 56u079390W, March and April 2000, Nupélia. MNRJ 29165, 1 CS, 20.5 mm SL, f; NUP 1959, 31, mm SL: Chapada dos Guimarães, Córrego Sujo, tributary to Manso Reservoir, approx. 14u529S, 55u479W, 20 May 2000, S. Veríssimo. NUP 2156, 14, mm SL, Chapada dos Guimarães, Córrego São Joaquim, tributary to Rio Manso (upstream from Manso Reservoir), approx. 14u569S, 55u399W, 19 July 2002, Nupélia. NUP 3332, 1, 27.3 mm SL, Nobres, Córrego Cancela, tributary to Rio Cuiabá, 14u429300S, 56u159510W, 20 July 2002, Nupélia. Diagnosis. Characidium nupelia is a member of a group of species (which includes C. xavante) uniquely diagnosed by the high number (12 18) of dark, vertical bars on the body, each bar having the width of a scale. Characidium nupelia is distinguished from C. xavante by a greater number of scales around the caudal peduncle (12 versus 10), narrower interorbital region (interorbital distance versus % HL) and deeper caudal peduncle (caudal peduncle depth % versus % HL). Conspicuous external characters which are not unique but are useful in recognizing the species include absence of adipose fin, incomplete lateral line, and a dark blotch on the caudal peduncle. Description. Morphometric data summarized in Table 1. Body laterally compressed. Dorsal profile convex between anterior tip of mesethmoid and posterior end of dorsal-fin base; almost straight or slightly concave between dorsal- and caudal-fin bases. Ventral profile convex, gently arched (somewhat more arched in breeding females) between lower jaw tip and posterior end of anal-fin base. Greatest body depth in front of dorsal-fin origin. Snout elongated in dorsal and lateral view. Mouth small, subterminal. Maxilla reaching vertical line through anterior margin of orbit. Orbit circular, slightly larger than snout length. Cheek smaller than orbit, its depth about one-third of orbit diameter. Nares separated; posterior naris considerably closer to eye than to anterior naris; margin of anterior naris raised, forming circular rim; dermal flaps absent from anterior and posterior nares. Dorsal cranial fontanel large, bordered anteriorly by frontals, posteriorly by supraoccipital. Branchiostegal rays 5(3); 4 attached to anterior ceratohyal (3). Isthmus completely covered with scales. Fig. 2. Partial view of the Characidum nupelia pelvic fin (anterior to left; arrows indicate sexual hooks). (A) Paratype, NUP 4106, 23.8 mm SL, cleared and stained; (B) Paratype, LIRP 5284, 24.7 mm SL. Fig. 3. Partial map of Brazil and adjoining countries showing the distribution of Characidium nupelia (dots; asterisk indicates type locality; one dot covers more than one locality) and C. xavante (square).

3 328 Copeia 2008, No. 2 Table 1. Morphometric Data of Characidium nupelia Holotype (MZUSP 87743) and Paratypes (LIRP 5284, 3; MZUSP 87742, 2; NUP 982, 9; NUP 1959, 15; NUP 2155, 3; NUP 2156, 1; NUP 3331, 2; NUP 3332, 1) and C. xavante Holotype (LIRP 5285) and Paratypes (NUP 3887, 15; NUP 3888, 14). SD, standard deviation. C. nupelia (n = 37) C. xavante (n = 30) Character Holotype Range Mean SD Holotype Range Mean SD Total length (mm) Standard length (mm) Head length (mm) Percents of standard length Body depth at dorsal-fin origin Body depth at anal-fin origin Body depth at caudal peduncle Head length Caudal peduncle length Preanal distance Predorsal distance Prepectoral distance Prepelvic distance Anal-apex distance Body width Percents of head length Snout length Orbital diameter Cheek depth Anterior naris orbit Posterior naris orbit Snout maxillary tip Interorbital distance Body depth at caudal peduncle All teeth conical. Single row of premaxillary teeth 7(1), 8(10), 9(21), 10(5*) decreasing gradually in size from symphysis towards lateral portion of premaxilla. Maxillary teeth absent. Dentary teeth 9(5), 10(22*), 11(10); their size decreasing gradually, from symphysis towards lateral posterior portion of dentary. Inner dentary teeth absent. Single row of ectopterygoid teeth 4(1), 5(1), or 6(1). Mesopterygoid teeth absent (3). Scales cycloid; parallel radii present on posterior region of scales. Axillary scale present. Lateral line incomplete 5(5), 6(17), 7(12*), 8(3) perforated scales; lateral row of scales 29(6), 30(13), 31(7), 32(10*), 33(1). Scale rows above lateral line 3(1), 4(24), 5(12*); below 4(10), 5(27*). Scales around caudal peduncle 12(37). Predorsal scale rows 10(4), 11(24), 12(9*). Dorsal-fin rays iii,9(28*), iii,10(9); pectoral-fin rays iii,8(19), iii,9(17*), iii,10(1); pelvic-fin rays i,7(8), i,8(29*); anal-fin rays iii,6(37*); caudal-fin rays i,8,7,i(2), i,8,8,i(10), i,9,8,i(25*). Distal portion of dorsal and anal fins slightly rounded. Pectoral and pelvic fins rounded. Caudal fin forked, with lobes rounded. Adipose fin absent. Total number of vertebrae 33(3). Supraneural bones between neural spine of fourth centrum and anterior dorsal-fin pterygiophore 5(3). Epural bones 2(3). Uroneural bones absent (3). Color in alcohol. Background color of head and body pale yellow. Chromatophores distributed over entire surface of head, including cheek and gular area; diffuse dark stripe extending from tip of snout to anterior margin of orbit, continuing from posterior margin of orbit to preopercle. Dark humeral spot conspicuously vertically elongated, anterior to pseudotympanum. Longitudinal stripe dark, narrow, usually diffuse, extending from humeral spot to dark horizontally elongate caudal peduncle blotch. Chromatophores concentrated on posterior margin of scales, giving reticulate aspect to lateral body region, mainly above longitudinal stripe and posterior to dorsal fin. Dark, vertical bars, frequently with darker irregular limits, 12(1), 13(1), 14(1), 15(6), 16(14*), 17(14) on lateral body region, diffuse below longitudinal stripe anterior to posterior end of dorsalfin base, more evident posteriorly; each bar having the width of a scale. Fins with dark chromatophores, more concentrated at their distal portions, sometimes forming dark band on distal third of anal fin. Sexual dimorphism. Small specimens with hyaline fins. Breeding males (above 21.0 mm SL) with anal, pelvic, and pectoral fins conspicuously dark, mainly on distal part of fin, and caudal fin hyaline. Females with dorsal, pectoral, pelvic, and anal fins notably lighter than males. Breeding males with blunt sexual hooks on distal portion of some branched rays of pelvic and pectoral fins, mainly in former; hooks more discernible in cleared-and-stained specimen (Fig. 2). Sexual hooks irregularly arranged, varying both in number and size across fin rays; each lepidotrichium having one hook at most. Females without sexual hooks on fins. Distribution. Tributary streams of Rio Cuiabá located in the highlands upstream from the Pantanal Matogrossense, upper Rio Paraguay basin, State of Mato Grosso, Brazil (Fig. 3).

4 Graça et al. Two new Characidium species 329 Fig. 4. Characidium xavante, holotype, LIRP 5285, male, 25.2 mm SL. Remarks. Characidium nupelia was collected sympatrically with the congeners Characidium sp. aff. C. zebra and C. laterale in all the streams, and Characidium sp. aff. C. gomesi in the Córrego São Joaquim. Characidium nupelia is popularly known in the sampled region as mocinha. Etymology. The species is named in recognition of the role of the Nupélia (Núcleo de Pesquisas em Limnologia, Ictiologia e Aqüicultura) in the survey and ecological research of the fish fauna from the Manso Reservoir region, which led to the discovery of this new species. The name is treated as a noun in apposition. Characidium xavante, new species Figures 3 5, Table 1 Holotype. LIRP 5285, 25.2 mm SL, m, Brazil, Mato Grosso, Primavera do Leste, Córrego Xavante, on the road from MT- Fig. 5. Partial view of the Characidum xavante pelvic fin (anterior to left; arrows indicate sexual hooks). (A) Paratype, NUP 4108, 22.8 mm SL, cleared and stained; (B) Holotype, LIRP 5285, 25.2 mm SL. 130 to Culuene dam, upper Rio Xingu basin, 14u389240S, 53u559380W, 18 Jan. 2002, L. Casatti, F. Gibran, A. Melo, and H. Santos. Paratypes. All from Brazil: Mato Grosso, upper Rio Xingu basin. LIRP 3982, 30, mm SL; MNRJ 29167, 10, mm SL; MZUSP 87745, 20, mm SL; NUP 3887, 18, mm SL; NUP 4107, 1 CS, 24.0 mm SL, f; NUP 4108, 1 CS, 22.8 mm SL, m: same data as holotype. LIRP 3913, 34, mm SL; MNRJ 29168, 1 CS, 20.5 mm SL, f; MNRJ 29168, 1 CS, 22.8 mm SL, m; MZUSP 87744, 20, mm SL; NUP 3888, 19, mm SL: Paranatinga, first stream after Rio Culuene bridge, from Paranatinga to Canarana, 13u559430S, 53u419450W, 20 Jan. 2002, L. Casatti, F. Gibran, A. Melo, and H. Santos. Diagnosis. Characidium xavante is a member of a group of species (which includes C. nupelia) uniquely diagnosed by the high number (12 18) of dark vertical bars on the body, each bar having the width of a scale. Characidium xavante is diagnosed by a lower number of scales around the caudal peduncle (10 versus 12 or more in most Characidium species). Characidium xavante is also distinguished from C. nupelia by the wider interorbital region (interorbital distance versus % HL) and lower caudal peduncle (caudal peduncle depth versus % HL). Conspicuous external characters that are not unique but are helpful to recognize the species include absence of adipose fin, incomplete lateral line, and a dark blotch on the caudal peduncle. Description. Morphometric data summarized in Table 1. Body laterally compressed. Dorsal profile convex between anterior tip of mesethmoid and posterior end of dorsal-fin base; almost straight or slightly concave between dorsal and caudal-fin bases. Ventral profile convex, gently arched (somewhat more arched in breeding females) between lower jaw tip and posterior end of anal-fin base. Greatest body depth in front of dorsal-fin origin. Snout elongated in dorsal and lateral view. Mouth small, subterminal. Maxilla reaching vertical line through anterior margin of pupil. Orbit circular, slightly larger than snout length. Cheek smaller than orbit, its depth about one-third of orbit diameter. Nares separated; posterior naris considerably closer to eye than to anterior naris; margin of anterior naris raised, forming circular rim; dermal flaps absent from

5 330 Copeia 2008, No. 2 anterior and posterior nares. Dorsal cranial fontanel large, bordered anteriorly by frontals, posteriorly by supraoccipital. Branchiostegal rays 5(3); 4 attached to anterior ceratohyal (3). Isthmus completely covered with scales. All teeth conical. Single row of premaxillary teeth 8(10), 9(18), 10(2*) decreasing gradually in size from symphysis towards lateral portion of premaxilla. Maxillary teeth absent. Dentary teeth 10(21*), 11(8), 12(1); their size decreasing gradually, from symphysis towards lateral posterior portion of dentary. Inner dentary teeth absent. Single row of ectopterygoid teeth 6(4). Mesopterygoid teeth absent (4). Scales cycloid; parallel radii present on posterior region of scales. Axillary scale present. Lateral line incomplete, 6(10*), 7(19), 8(1) perforated scales; lateral row of scales 30(4), 31(9*), 32(11), 33(6). Scales row above lateral line 4(11*), 5(19); below 4(15), 5(15*). Scales around caudal peduncle 10(30). Predorsal scale rows 10(4), 11(7*), 12(13), 13(6). Dorsal-fin rays iii,9(11*), iii,10(19); pectoral-fin rays iii,8(15*), iii,9(10), iii,10(5); pelvic-fin rays i,7(13*), i,8(17); anal-fin rays iii,6(14), iii,7(16*); caudal-fin rays i,8,8,i(7), i,9,8,i(23*). Distal portion of dorsal and anal fins slightly rounded. Pectoral and pelvic fins rounded. Caudal fin forked, with lobes rounded. Adipose fin absent. Total number of vertebrae 32(3), 33(1). Supraneural bones between neural spine of fourth centrum and anterior dorsalfin pterygiophore 4(2) or 5(2). Epural bones 2(4). Uroneural bones absent(4). Color in alcohol. Background color of head and body pale yellow. Chromatophores distributed over entire surface of head, including cheek and gular area; diffuse dark stripe extending from tip of snout to anterior margin of orbit, continuing from posterior margin of orbit to preopercle. Dark humeral spot conspicuously vertically elongated, anterior to pseudotympanum. Longitudinal stripe dark, narrow, sometimes diffuse, extending from humeral spot to dark horizontally elongate caudal peduncle blotch. Chromatophores concentrated on posterior margin of scales, giving reticulate aspect to lateral body region, mainly above longitudinal stripe and posterior to dorsal fin. Dark, vertical bars, frequently with darker irregular limits, 12(1), 13(1), 14(1), 15(3), 16(6*), 17(10), 18(8) on lateral body region, diffuse below longitudinal stripe anterior to posterior end of dorsal-fin base, more evident posteriorly, each bar having the width of a scale. Fins with dark chromatophores, more concentrated at their distal portions, sometimes forming dark band on distal third of anal fin. Sexual dimorphism. Small specimens with hyaline fins. Breeding males (above than 22.0 mm SL) with anal, pelvic, and pectoral fins conspicuously dark, mainly on distal part of fin, and caudal fin hyaline. Females with dorsal, pectoral, pelvic, and anal fins notably lighter than males. Breeding males with blunt sexual hooks on distal portion of some branched rays of pelvic and pectoral fins, mainly in former; hooks more discernible in cleared-and-stained specimen (Fig. 5). Sexual hooks irregularly arranged, varying both in number and size across fin rays; each lepidotrichium having one hook at most. Females without sexual hooks on fins. Distribution. Known from the Rio Culuene watershed, in the upper Rio Xingu drainage, State of Mato Grosso, Brazil (Fig. 3). Remarks. Characidium xavante was collected with the congener Characidium sp. aff. C. zebra. Etymology. The specific epithet xavante is in reference to the type locality. Xavante is a name of an indigenous Brazilian ethnic group, inhabiting the region between the Rio das Mortes and Rio Culuene, State of Mato Grosso. The stream at the type locality is also named after this ethnic group. A noun in apposition. DISCUSSION The two new species described herein are remarkably similar, and we hypothesize that they form a monophyletic group, which is provisionally supported by the relatively high number (12 or more) of vertical bars in the body, each bar having the width of a scale. Most species of Characidium have 9 12 vertical bars. This feature appears to be unique among species currently assigned to the genus Characidium. Fowler (1941) reported the presence of 14 vertical bars in C. bimaculatum, but the examination of the holotype photo indicates that it has about ten bars. Apparently, Fowler (1941) interpreted the darker margins of the lower portions of each individual bars, which may produce the impression of a double bar. High numbers of vertical bars also occur in the psammophile species C. heinianum, C. longum, C. pellucidum, and C. pteroides. In those species, however, the chromatophores are not arranged in a wide stripe, but, instead, they form narrow lines or spots. These species share a number of apomorphic features with C. steindachneri,suchasanelongated body, a ventrally positioned mouth, an ellipsoidal supraorbital, and a high number of vertical body markings, which is parsimoniously regarded as having an independent origin. The new species also share additional conspicuous apomorphic characters that are consistent with a hypothesis of close relationship: reduction of the lateral line, presence of a conspicuous blotch on the caudal peduncle near the basis of the caudal fin, and absence of an adipose fin. The absence of the adipose fin seems to be a constant feature of both species, occurring in all examined specimens (161 of C. nupelia, 156 of C. xavante including material not preserved). These characters are not unique to the two species, but support the hypothesis that they belong to the same clade of species of Characidium. Among species of Characidium, an incomplete lateral line is also found in C. bahiense, C. interruptum, C. laterale, C. rachovii, and C. stigmosum. Among these species, the adipose fin is also absent in C. stigmosum, and the caudal blotch is most similar to the blotch that occurs in C. bahiense. Accepting a hypothesis of close relationship with C. stigmosum, however, requires further phylogenetic investigation, because the adipose fin is also absent in species with a complete or almost complete lateral line, such as C. vestigipinne and various undescribed species, Buckup (pers. obs.). Such a comprehensive phylogenetic revision of Characidium is beyond the scope of this paper. Likewise, accepting a hypothesis of close relationship with C. bahiense requires investigation of relationships of other species with a conspicuous caudal blotch. Among species with a complete lateral line, the caudal blotch is most similar to the blotch of C. lagosantense and C. bimaculatum, but the blotch is variably developed among various species of Characidium. Additionally, a close relationship between the two new species and Geryichthys sterbai cannot be ruled out, as all three species share a reduced lateral line and the absence of the adipose fin. Additionally, G. sterbai also has a

6 Graça et al. Two new Characidium species 331 high number of vertical bars in the body. Inclusion of Geryichthys in the genus Characidium is currently being investigated elsewhere (Buckup and S. Weitzman, unpubl. data). A trait shared by the two new species and which has been, to date, poorly described for Characidium species is the presence of sexually dimorphic hooks on the branched pelvic and pectoral-fin rays of males, mainly on the former. It is noteworthy that this feature has only been mentioned once previously for Characidium species, by Almeida (1971), who observed hooks on the rays of the same fins in C. bahiense. Hooks are commonly found on the anal-fin rays of breeding males of Characidae (Malabarba and Weitzman, 2003). However, the structures present in C. nupelia and C. xavante have a blunt tip and do not resemble a typical hook. A cursory examination of some congeners revealed the presence of these structures in some paratypes of C. lagosantense, but they were not found in C. gomesi, C. interruptum, C. laterale, Characidium sp. aff. C. zebra, and other undescribed species. Nevertheless, further examination in populations of these and other Characidium species captured during the breeding period is required to establish the distribution of these structures. Wiley and Collette (1970) reported contact organs in several Neotropical fish species, and stated that these structures originally evolved to enable breeding individuals to maintain close contact in spawning to ensure fertilization of the eggs. These structures have been reported as hooks in a large number of Neotropical Characiformes (review in Malabarba and Weitzman, 2003), and Vari and Ferraris (2004) reported contact organs in an African characiform. These structures may greatly vary in shape, but are always a bony spiny process developed on the surface of individual segments of lepidotrichia (Malabarba and Weitzman, 2003), and may be interpreted not as contact organs, but as supporting structures of skin flaps or glandular tissue (L. Malabarba, pers. comm.). The occurrence of sexual hooks in Characidium suggests that hooks are more widespread in Characiformes than had been previously supposed. MATERIAL EXAMINED All from Brazil. Characidium bahiense: MZUSP 8940, holotype, 16.0 mm SL, Bahia, Arembepe. C. bimaculatum: ANSP 69523, holotype, 31.8 mm SL, Ceará, Fortaleza. C. gomesi: NUP 1092, 7, mm SL, Goiás, Caldas Novas, Rio Corumbá tributary to Rio Paranaíba; NUP 3815, 1, 41.2 mm SL, Goiás, Terezópolis, Córrego Maria Paula, 16u289140S, 49u069140W; NUP 3816, 2, mm SL, Goiás, Anápolis, Córrego Cunha, 16u209250S, 49u079020W. Characidium sp. aff. C. gomesi: MZUSP 78824, 10, mm SL, Mato Grosso, Reserva do Cabaçal, Ribeirão Sete de Setembro, below Chuva de Prata Falls, 15u059120S, 58u209510W; NUP 3326, 2, mm SL, Mato Grosso, Chapada dos Guimarães, Córrego São Joaquim, tributary to Rio Manso. C. interruptum: MNHN , holotype, 31.4 mm SL, Brazil, Serra d Estrello; MZUSP 80219, 2, mm SL, Rio de Janeiro, Silva Jardim, tributary to Rio São João, 28 km N of road Boqueirão-Japuíba, 22u349S, 42u349W. C. lagosantense: MNRJ 4582, holotype, 23.4 mm SL, Minas Gerais, Rio das Velhas; MNRJ and 4588, 4 paratypes, mm SL, same locality as MNRJ C. laterale: BMNH , syntype, 23.4 mm SL; MZUSP 36405, 13, mm SL, Mato Grosso do Sul, Corumbá, Baía dos Búfalos, Nhumirim farm (Nhecolândia), 19u159S, 57u029W; NUP 3319, 12, mm SL, Mato Grosso, Barão de Melgaço, Baía de Chacororé (Rio Cuiabá), 16u309S, 56u329W. C. lauroi: MZUSP 71848, 10, mm SL, São Paulo, Guapiara, Córrego de Francisca Gomes (Pedra do Fogo, Parque Estadual de Intervales). C. rachovii: BMNH , syntype, 32.5 mm SL, Rio Grande do Sul, Vila da Quinta, Rio Grande. C. serrano: MCP 12488, holotype, 50.0 mm SL, Santa Catarina, Concórdia, Rio Jacutinga on road (BR283) between Seara and Concórdia, 27u109S, 52u099W; MCP 12038, paratype, 47.5 mm SL, Santa Catarina, Campos Novos, Rio Canoas at Passo do Canoas on road Tupitinga/Celso Ramos (SC458). Characidium sp. aff. C. zebra: NUP 1196, 100, mm SL, Goiás, Caldas Novas, Rio Corumbá, tributary to Rio Paranaíba; NUP 1206, 54, mm SL, Goiás, Caldas Novas, Rio Gameleira, tributary to Rio Corumbá; NUP 2302, 3, mm SL, Goiás, Mineiros, Rio Formoso (Parque Nacional das Emas), 18u159S, 53u009W; NUP 1384, 4, mm SL, Paraná, Jussara, Rio Abelha, tributary to Rio Ivaí. Characidium sp. A: NUP 708, 17, mm SL, Paraná, Capitão Leônidas Marques, Caxias Reservoir (Rio Iguaçu); NUP 1666, 2, mm SL, Paraná, Foz do Jordão, Jordão Reservoir (Rio Jordão), tributary to Rio Iguaçu, 25u309S, 53u259W; NUP 2392, Paraná, Mangueirinha, Segredo Reservoir (Rio Iguaçu), 25u459S, 52u059W. Characidium sp. B: MZUSP 85938, 10 of 17, mm SL, Paraná, Pinhão, river at 8 km West of Pinhão on the road Pinhão-Reserva do Iguaçu, 25u S, 51u W. ACKNOWLEDGMENTS Thanks are due to C. Figueiredo for critically reading the manuscript; J. Stanley for revising the English; A. Akama and J. Birindelli for sending bibliographic references; R. Camposda-Paz, C. Zawadzki, and L. Silveira for examining type-series deposited at MNRJ, BMNH, and MNHN; M. Sabaj for sending photo of holotype of C. bimaculatum; F. Bockmann, Z. Lucena, R. Reis, M. de Pinna, and O. Oyakawa for loaning material; A. Bialetzki for helping with the clearing and staining of specimens; M. Campos, E. Ikedo, and H. Suzuki for recognizing sexes and reproductive stages of specimens; A. Cunico and C. Moresco for photographing the type material; L. Malabarba and L. Silveira for providing useful comments and information about the hooks. Nupélia and Furnas Centrais Elétricas S/A offered logistic support. Part of the field work was supported by a PRONEX-LIRP grant from CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico). This study was supported by grants from CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) to WJG, and CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) to CSP (Proc /2006-2) and PAB (Proc /2003-1, /2006-1, /2006-7). LITERATURE CITED Almeida, V. G Descrição de uma nova espécie do gênero Characidium (Pisces, Characidae). Papéis Avulsos de Zoologia, São Paulo 25: Buckup, P. A. 1993a. The monophyly of the Characidiinae, a Neotropical group of characiform fishes (Teleostei,

7 332 Copeia 2008, No. 2 Ostariophysi). Zoological Journal of the Linnean Society 108: Buckup, P. A. 1993b. Review of the characidiin fishes (Teleostei: Characiformes), with descriptions of four new genera and ten new species. Ichthyological Exploration of Freshwaters 4: Buckup, P. A Family Crenuchidae (South American darters), p In: Check List of the Freshwater Fishes of South and Central America. R. E. Reis, S. O. Kullander, and C. J. Ferraris,, Jr. (eds.). EDIPUCRS, Porto Alegre, Brazil. Fowler, H. W A collection of fresh-water fishes obtained in Eastern Brazil by Dr. Rodolpho von Ihering. Proceedings of the Academy of Natural Sciences of Philadelphia 93: Malabarba, L. R., and S. H. Weitzman Description of a new genus with six new species from southern Brazil, Uruguay and Argentina, with a discussion of a putative characid clade (Teleostei: Characiformes: Characidae). Comunicações do Museu de Ciências e Tecnologia da PUCRS, Série Zoologia 16: Taphorn, D. C. B., C. G. Montaña, and P. A. Buckup Characidium longum (Characiformes: Crenuchidae), a new fish from Venezuela. Zootaxa 1247:1 12. Taylor, W. R., and G. C. Van Dyke Revised procedures for staining and clearing small fishes and other vertebrates for bone and cartilage study. Cybium 9: Vari, R. P., and C. J. Ferraris, Jr A new species of Nannocharax (Characiformes: Distichodontidae) from Cameroon, with the description of contact organs and breeding tubercles in the genus. Proceedings of the Biological Society of Washington 117: Wiley, M. L., and B. B. Collette Breeding tubercles and contact organs in fishes: their occurrence, structure, and significance. Bulletin of the American Museum of Natural History 143: