Hoplias intermedius ( Günther, 1864 )

Oyakawa, Osvaldo T. & Mattox, George M. T., 2009, Revision of the Neotropical trahiras of the Hoplias lacerdae species-group (Ostariophysi: Characiformes: Erythrinidae) with descriptions of two new species, Neotropical Ichthyology 7 (2), pp. 117-140 : 129-133

Hoplias intermedius ( Günther, 1864)

Fig. 8

Erythrinus brasiliensis : - Castelnau, 1855:56 [misidentification, occurrence in the rio Carandaí, rio Paraná drainage, differences from Erythrinus trahira ].

Macrodon intermedius Günther, 1864: 282 [original description; type locality: rio Cipó, Minas Gerais State, Brazil; syntypes: BMNH 1861.5.16.6-7, dried and stuffed specimens]. - Steindachner, 1874: 26 [species list as synonym of Macrodon trahira ]. - Eigenmann & Eigenmann, 1889: 103 [species list as synonym of Macrodon malabaricus ]. - Eigenmann, 1910: 448 [species list as synonym of Hoplias malabaricus ]. - Fowler, 1950: 364 [species list, synonym of Hoplias malabaricus malabaricus ]. - Godoy, 1975: 406 [synonym of Hoplias malabaricus malabaricus ]. - Lütken, 2001: 78 [as synonym of Macrodon trahira ]. - Oyakawa, 2003: 239 [as synonym of Hoplias microcephalus ].

Hoplias lacerdae : - Britski, 1972: 81-82 [in part, species list, differences from H. malabaricus , occurrence in the rio Paraná basin]. - Bertollo et al., 1978 [occurrence in upper rio Grande, upper Paraná, karyotype description]. - Bizerril, 1994: 56 [in part, occurrence in rios Paraná and São Francisco]. - Penczak et al., 1998: 92 [occurrence in the rio Ivaí, rio Paraná basin]. -Agostinho & Júlio Jr., 1999: 382 [occurrence in upper rio Paraná]. - Meschiatti et al., 2000: 135 [occurrence of juveniles in floodplains of rio Mogi- Guaçú, upper Paraná]. -Alves & Pompeu, 2001 [occurrence in upper rio São Francisco]. -Barrella & Petrere Jr., 2003: 65 [occurrence in the rio Tietê basin, upper rio Paraná]. - Pompeu & Alves, 2003: 133 [hypothesis of introduction into the rio São Francisco basin]. -Alvim & Peret, 2004: 198 [diet in the rio São Francisco]. - Vieira et al., 2005: 80 [occurrence in upper reaches of rios São Francisco and Doce]. -Cunico & Agostinho, 2006: 128 [occurrence in tributary to rio Ivaí, rio Paraná basin]. - Silva et al., 2006a: 832 [occurrence in the rio São Francisco]. - Silva et al., 2006b: 3572 [occurrence in the rio Tietê, upper rio Paraná].

Hoplias cf. lacerdae : - Britski et al., 1984:55 [identification key, occurrence in Três Marias Dam, rio São Francisco drainage].

Hoplias aff. lacerdae : -Sato & Godinho, 1999:411 [occurrence in the rio São Francisco basin].

Lectotype. BRAZIL. Minas Gerais State. São Francisco basin: BMNH 1861.5 .16.6, 533.4 mm SL, rio Cipó , no date, Ch. Cumberland. Dry and mounted specimen ( Fig. 9 ), [designated herein].

Paralectotype. BRAZIL. Minas Gerais State. São Francisco basin: BMNH 1861.5 .16.7, 279.4 mm SL, same locality and collector. Skin [designated herein] .

Material examined. BRAZIL. Bahia State. São Francisco basin: MZUSP 94050, 1, 73.5 mm SL, rio Formoso, tributary to rio Corrente, Colônia do Formoso; MZUSP 94434, 15, 17.6-181.7 mm SL, riacho do Morro Furado, tributary to rio Corrente near mouth of Gruta do Morro Furado, Coribe; MZUSP 94667, 2, 14.8-27.7 mm SL, riacho do Morro Furado, tributary to rio Corrente, Coribe; MZUSP 94436, 2, 284.2- 309.8 mm SL; MZUSP 94437, 1, 284.9 mm SL, Sobradinho Dam, rio São Francisco. Minas Gerais State. São Francisco basin: INPA 26894, 4, 242.7-282.0 mm SL; MCP 13994, 1, 448.4 mm SL; MCP 13995, 1, 367.2 mm SL; MZUSP 24638, 3, 275.8- 374.4 mm SL; MZUSP 38639, 10, 235.8- 349.3 mm SL, Três Marias Reservoir, rio São Francisco; MZUSP 38052, 1, 58.9 mm SL, Três Marias Reservoir near Morada Nova de Minas; MCP 14091, 1, 392.0 mm SL; MCP 14092, 1, 420.2 mm SL; MCP 14102, 1, 401.0 mm SL; rio São Francisco between Três Marias and Pirapora; MZUSP 1495, 1, 146.6 mm SL, rio São Francisco, Pirapora; MZUSP 25062, 1, 47.9 mm SL, córrego do Julião, on the road to Jaboticatubas; MZUSP 37157, 9, 35.3-47.7 mm SL, stream tributary to rio Paraopeba, Moeda; MZUSP 37252, 3, 130.4- 162.7 mm SL, lagoa da Prata, rio São Francisco; MZUSP 38571, 2, 375.5- 377.8 mm SL, córrego Água Limpa, tributary to rio Abaeté; MZUSP 39239, 1, 20.0 mm SL, lagoon on right bank of córrego Braço Grande, rio São Francisco; MZUSP 39275, 1, 105.0 mm SL, Ilha Grande, rio São Francisco; MZUSP 39381, 2, 16.4-53.2 mm SL, lagoa do Praiano, left bank of rio São Francisco; MZUSP 39565, 1, 102.6 mm SL, córrego Ribeiro Manso, tributary to rio Abaeté; MZUSP 39571, córrego Água Limpa, tributary to rio Abaeté; MZUSP 39628, 1, 127.2 mm SL, córrego Capivara, tributary to rio Abaeté; MZUSP 39652, 2, 140.1- 196.9 mm SL, córrego Chumbo, tributary to rio Abaeté; MZUSP 39700, 1, 240.8 mm SL, rio São Francisco at Pontal do Abaeté; MZUSP 39741, 4, 169.8- 265.9 mm SL, rio São Francisco and tributaries, Formoso Hydroelectric Station area; MZUSP 39779, 1, 22.5 mm SL, rio São Francisco at mouth of rio Formoso; MZUSP 47268, 2, 42.6-128.2 mm SL, stream under bridge of BR 135 road, between Corinto and Augusto de Lima; MZUSP 47325, 1, 67.8 mm SL, stream tributary to rio Jequitaí, on BR 135 road, between Buenópolis and Engenheiro Dolabela; MZUSP 54696, 2, 40.5-42.1 mm SL, rio Cipó, circa 10 km southeast of BR 259 road, Presidente Juscelino; MZUSP 73655, 1, 105.7 mm SL, rio Cipó, Presidente Juscelino; MZUSP 73735, 1, 164.2 mm SL, rio Bicudo, Fazenda Bom Jardim, Corinto; MZUSP 73837, 1, 249.9 mm SL, Lagoa Santa, rio das Velhas drainage; MZUSP 73839, 1, 274.8 mm SL, rio Curimataí, Fazenda Vitória, Augusto de Lima; MZUSP 73842, 1, 259.9 mm SL, central lagoon in Lagoa Santa; MZUSP 79247, Gruta Morena, Cordisburgo; MZUSP 86019, 1, 73.8 mm SL, rio Verde Grande, Montes Claros; MZUSP 94433, 2, 45.0- 52.2 mm SL, lagoa Azul, rio das Velhas Basin, Cordisbugo; MZUSP 94435, 6, 34.2-257.2 mm SL, ribeirão da Onça, tributary to rio das Velhas, Cordisburgo; Minas Gerais State. Jequitinhonha basin: MZUSP 38830, 3, 147.3- 221.7 mm SL, rio Araçuai downstream from the rio Fanado, Santa Rita. Minas Gerais State. Doce basin: MZUSP 74659, 1, 29.6 mm SL, rio Guanhães, Dores de Guanhães; MZUSP 75289, 2, 27.5-68.0 mm SL, rio Santo Antônio, Fazenda Campinas, Conceição do Mato Dentro; MZUSP 75331, 1, 276.7 mm SL, rio Santo Antônio, Santo Antônio; MZUSP 73113, 1, 313.4 mm SL, córrego da Fonseca, rio Santo Antônio, 11 km from Santo Antônio, São Sebastião do Rio Preto; MZUSP 75357, 1, 160.1 mm SL, rio Santo Antônio, Santo Antônio; MZUSP 80937, 1, 355.0 mm SL, rio Tronqueiras, São José de Tronqueiras near border with Coroací, Governador Valadares; MZUSP 69329, 2, 21.1-25.9 mm SL, rio Suaçuí Pequeno upstream from waterfall, Coroaci; MZUSP 69357, 2, 17.3-25.4 mm SL, rio Suaçuí Pequeno, upstream from and near the bridge of Procópio, Coroaci; MZUSP 69370, 1, 169.3 mm SL, rio Suaçuí Pequeno, downstream from the bridge of Procópio, Coroaci; MZUSP 66196, 2, 28.1-89.6 mm SL, rio Suaçuí Grande, downstream from the Traíra II Hydroelectric Station, Peçanha; MZUSP 87813, 1, 102.1 mm SL, stream tributary to rio Santo Antônio, Serro; MZUSP 87816, 1, 172.4 mm SL, small waterfall in córrego Claudiano, tributary to rio do Peixe, rio Santo Antônio drainage, Serro; MZUSP 87824, 1. 71.1 mm SL, Cachoeira do Cancão, rio Mãe d’Água, tributary to rio Santo Antônio, Santo Antônio do Itambé. Minas Gerais State. Paraíba do Sul basin: MZUSP 81011, 2, 248.7- 267.2 mm SL, rio Glória, tributary to rio Muriaé, Muriaé, rio Paraíba do Sul basin. Minas Gerais State. upper Paraná basin: MZUSP 44019, 1, 116.7 mm SL, Camargos Reservoir, rio Grande, São João del Rei; MZUSP 51460, 4, 201.5- 277.5 mm SL, rio Grande, Itutinga Hydroelectric Station; MZUSP 51469, 1, 142.5 mm SL, rio Pará, Cajuru Hydroelectric Station, Carmo do Cajuru; MZUSP 51994, 4, 140.1- 290.6 mm SL, Camargos Reservoir, rio Grande; MZUSP 38638, 1, 312.1 mm SL, rio Paranaíba, Bocaina Hydroelectric Station. São Paulo State. upper Paraná basin: MZUSP 23006, 2, 252.8- 430.5 mm SL; MZUSP 24827, 23, 135.2- 322.9 mm SL; MZUSP 45580, 1, 315.0 mm SL, rio Pardo, Limoeiro Hydroelectric Station, São José do Rio Pardo. Paraná State. upper Paraná basin: MZUSP 38570, 1, 113.6 mm SL, mouth of rio Cantú, tributary to rio Piquirí, Campina da Lagoa; MZUSP 39780, 2, 171.8- 245.8 mm SL, rio Piquirí, Campina da Lagoa.

Diagnosis. Hoplias intermedius differs from the others species of the H. lacerdae group, but H. australis and H. lacerdae , in the number of scales along lateral line (42-46 vs. 38-43 in H. brasiliensis and 34-39 in H. curupira ). It can be further distinguished from H. australis and H. lacerdae , in the number of pores of the laterosensory system along the ventral surface of dentary (4-6 vs. always 5 and 6-8 respectively). The shape of anterior profile of head further distinguished H. intermedius from H. australis (angular vs. rounded respectively).

Description. Morphometric data presented in Table 6. Body cylindrical, deeper than wide. Greatest body depth at vertical through fifth scale anterior to dorsal-fin origin in specimens smaller than 40 mm SL, closer to dorsal-fin origin in larger specimens. Anterior profile of head rounded in lateral view in specimens smaller than 40 mm SL, more angular in larger specimens. Dorsal profile of head varying from slightly convex in specimens smaller than 40 mm SL to gradually becoming straighter in larger specimens. Dorsal margin of orbit located at horizontal through of dorsal profile of head in specimens smaller than 130 mm SL, but not reaching dorsal profile of head in larger specimens (ca. 300 mm SL). Dorsal profile of body slightly convex from vertical through first series of scale of body to dorsal-fin origin; straight and posteroventrally inclined along dorsal-fin base; straight and less inclined to slightly concave from vertical through base of last dorsal-fin ray to origin of dorsal most procurrent caudal-fin ray. Ventral profile of lower jaw distinctly angular in region of mandibular symphysis, straight to slightly inclined from vertical through anterior nostril to posterior margin of lower jaw. Medial margins of contralateral dentaries running in parallel ( Fig. 1 a-c). Ventral profile of body slightly convex to pelvic-fin origin; approximately straight to slightly convex from latter point to anal-fin origin; straight and posterodorsally inclined along anal-fin base; slightly concave from base of last anal-fin ray to anterior most ventral procurrent caudal-fin ray.

Upper and lower jaws of similar size in specimens smaller than 40 mm SL, upper jaw gradually becoming shorter than lower jaw in larger specimens. Posterior portion of maxilla dorsally enlarged and extending medial to anterior margins of second and third infraorbitals. Upper and lower lips fleshy with short projections of skin covering canines externally. Anterior nostril tubular with anterior slit along its distal half. Anterior and posterior nostrils situated along horizontal through center of orbit, anterior nostril located at two-thirds of orbital diameter from anterior margin of orbit; posterior nostril situated midway between anterior nostril and anterior margin of orbit. Eye proportionately larger in smaller specimens. Infraorbital bones well-developed and horizontally elongate. Infraorbitals 3, 4, and ventral portion of 5 partially covering preopercle. Anteroventral margin of infraorbital 3 relatively straight and posteroventral margin convex. Posterior margin of infraorbitals 4, 5, and 6 slightly convex. Small specimens (ca. 40 mm SL) with infraorbital 3 barely reaching orbital rim and proximal ends of infraorbitals 2 and 4 almost in contact. Larger specimens (ca. 130 mm SL) with infraorbitals 3 and 4 completely excluded from orbital rim and infraorbital 5 progressively separated from rim in larger specimens. Proximal ends of infraorbitals 2 and 6 almost meeting in some of the largest specimens examined (ca. 300 mm SL).

Teeth in both jaws conical or canine. Premaxillary teeth in single row. First premaxillary tooth large canine, second and seventh teeth medium sized. Eighth tooth canine almost as large as anterior most premaxillary canine. Third to sixth, and ninth premaxillary teeth small. Maxillary with single row of approximately 32 relatively small teeth, except for very well developed canine-like fourth tooth. Dentary with anterior external row of teeth and posterior internal row. External series with three anterior small teeth, followed by two well developed canines with posterior canine larger than anterior canine, and then 11 conical teeth slightly smaller than anterior most dentary canine. Internal series beginning at level of last conical tooth of external row and composed of approximately 18 very small teeth. Accessory ectopterygoid and ectopterygoid toothed. Ectopterygoid with series of small conical teeth along ventrolateral margin and many smaller viliform teeth on ventromedial surface. Endopterygoid edentulous.

Distal margins of all fins rounded. Total dorsal-fin rays 13-15 (n = 98; ii,11-13; mode: ii,12, n = 44). Dorsal fin located at midbody, its origin at vertical through approximately fourth scale anterior on series along pelvic-fin origin. Longest dorsalfin ray approximately three-quarters of body depth. Anal-fin base short. Total anal-fin rays 9-11 (n = 97; ii,7-9; mode: ii,8, n = 88). Tip of depressed dorsal fin reaching vertical through anal-fin origin in small specimens (<130 mm SL) but falling short of that point in larger specimens. Total pectoral-fin rays 12-14 (n = 89; i,11-13; mode: i,11, n = 55). Pectoral-fin origin located at vertical through median region of opercle. Tip of pectoral fin separated from pelvic-fin origin by four to six scales. Pectoral and pelvic fins of similar size and slightly smaller than anal fin. Pelvic-fin rays i,7 (n = 97, i, 8 in one specimen). Pelvic-fin origin situated at midbody and approximately four scales posterior to vertical through dorsalfin origin. Tip of pelvic fin separated from vertical through anal-fin origin by four or five scales. Caudal-fin rays i,15,i (n = 88, 13 branched rays in one specimen and 14 branched rays in six specimens).

Well developed cycloid scales imbricated along body. Dorsal scales begin in series at posterior margin of parietals and overlap supraoccipital spine. Last vertical series of scales on caudal peduncle forms slightly convex arch on caudal-fin base in lateral view. Anterior margin of scales with small recess and posterior margin rounded. Approximately eight radii extending from center of scale to its anterior margin and around eighteen radii, some anastomosed, extending from center of scale to its dorsal, posterior, and ventral margins. Lateral line straight and complete, extending from posteroventral margin of supracleithrum to posterior most scale in body. Lateral line with 42-46 (n = 90, 42 in five specimens and 46 in four specimens; mode: 44, n = 36) perforated scales ( Table 2). Lateral-line scales with single laterosensory canal. Longitudinal series of scales between lateral line and dorsalfin origin 5.5-6.5 (n = 92; mode: 5.5, n = 86). Longitudinal series of scales between lateral line and pelvic-fin origin 4.5- 5.5 (n = 93; mode: 5.5, n = 75). Longitudinal series of scales around caudal peduncle 20 (n = 92).

Approximately 9 gill rakers on first epibranchial, most in form of small denticulated plates. Lower branch of first branchial arch with five or six more elongate rakers and approximately 10 plate-like rakers (n = 96). Laterosensory canal along ventral surface of dentary with 4-6 pores (n = 97; mode: 5, n = 74) ( Table 3).

Color in alcohol. Ground coloration of head and body dark to light brown, darker dorsally and paler ventrally. Ventral region white in several specimens. Approximately seven dark parallel diagonal bars along dorsal region, bars extending anteroventrally to just below lateral line. Diagonal bars in many specimens continuing posteroventrally to approximately two longitudinal scale series below lateral line, resulting in chevron-like pattern. Dorsal portions of bars more evident than ventral region. Bars more conspicuous in specimens with light brown ground coloration. Dorsal surface of head dark brown. Lips with alternating dark and light vertical bands, but completely black in some of largest specimens examined (ca. 300 mm SL). Ventral surface of dentaries varying from white in small specimens (ca. 40 mm SL), to alternating dark and light transverse stripes in specimens around 130 mm SL, to completely dark in larger specimens. Coloration of infraorbital region and dorsal surface of head similar. Many specimens with two dark stripes radiating posteriorly from eye along infraorbital 6 and dorsal portion of infraorbital 3. Ground coloration of opercular series dark brown. Opercular membrane usually lighter than opercle.

All fins light brown, lighter than body in specimens smaller than 130 mm SL, with dark spots on rays and interradial membranes forming pattern of irregular dark stripes. Stripes on anal and caudal fins wider and more regular than those on dorsal fin. Ventral surfaces of pectoral and pelvic fins either lighter than, or with same pattern as, dorsal surface, but with pattern less conspicuous. Fins of largest specimens (ca. 300 mm SL) usually darker than rest of body.

Distribution. In the rio São Francisco basin and upper reaches of rio Paraná basin, including rios Grande, Paranaíba and Piquiri. Hoplias intermedius also occurs in tributaries of rio Doce, Minas Gerais State ( Fig. 3 ).

Remarks. Syntypes of Macrodon intermedius are deposited in the BMNH collection, and permit its clear placement in the Hoplias lacerdae group. Data presented herein matches information from the original description of M. intermedius . Oyakawa (1990) included the nominal species Erythrinus microcephalus Agassiz, 1829 and Macrodon intermedius Günther, 1864 in the Hoplias lacerdae group, with latter being considered a junior synonym of the former ( Oyakawa, 2003). These names are available for the taxon occurring in the upper rio São Francisco drainage, since E. microcephalus was described from “rio São Francisco” and M. intermedius from “rio Cipó”, one of its tributaries. As discussed above, many specimens of species described by Spix and Agassiz (1829) were lost during World War II, as well as the holotype of Erythrinus microcephalus is also missing ( Terofal, 1983; Kottelat, 1988). Unlike the situation with Erythrinus brasiliensis (see above), the original description of E. microcephalus , although mentioning that the tongue is edentate, is unclear as to the alignment of the contralateral dentaries noting only that “branches of the lower jaw narrow and convex throughout their length, farther apart when the mouth is closed and distant from the other by a greater space than their transverse diameter” [our translation]. This makes it difficult to determine whether Hoplias microcephalus belongs to the H. lacerdae or to the H. malabaricus species groups. Neither Hoplias microcephalus nor H. intermedius have been recently used, except for a catalog based on preliminary data ( Oyakawa, 2003), but previous authors included both epithets as synonyms of H. malabaricus (e. g. Steindachner, 1874; Lütken, 2001). The younger name, H. intermedius is certainly a member of the H. lacerdae group whereas the older one, H. microcephalus cannot be unambiguously assigned to this group. Since neither these names has been used recently, H. intermedius is herein chosen to designate this taxon.

In describing Macrodon intermedius, Günther (1864) cited two specimens, but made no reference to either being the holotype, and both are thus syntypes of the species. Following Article 74 of the International Code of Zoological Nomenclature ( ICZN, 1999), one of the syntypes is designated a lectotype (BMNH 1861.5.16.6) ( Fig. 9 ), and the other becomes a paralectotype (BMHN 1861.5.16.7).

Hoplias intermedius has an interesting disjunct distribution, occurring in the upper stretches of rio São Francisco, rio Doce and rio Paraná. In the latter basin, the species is not known to occur downstream of the Sete Quedas. Similar distributions are reported for other fish species ( Menezes, 1988; Vari & Harold, 2001). Dergam et al. (2002) demonstrated that populations of H. malabaricus from the upper rio Doce, upper rio Paraná, and upper rio Paraíba do Sul are genetically close, indicating a possible common origin or recent exchanges between these basins. Vieira et al. (2005) also suggested a common ancestry between the rios São Francisco and Doce based on their ichthyofauna.

Current knowledge of the geological history of eastern South America indicates that the origin of coastal rivers involved successive erosion of the eastern margin of the platform associated with consequent upland river capture, giving rise to the various independent basins draining into the Atlantic Ocean ( Potter, 1997; Ribeiro, 2006). According to these authors, six major uplift events created megadomes that worked synergistically with marginal erosion and upland stream capture along the Atlantic coast of South America when the latter and Africa were separated during the opening of the Atlantic Ocean. One of these megadomes, the “Mantiqueira-Angola”, is represented in Brazil by highlands extending from São Paulo and Rio de Janeiro states north to Minas Gerais state, and was responsible for isolating the upper stretches of the rios São Francisco, Paraná and Doce. Therefore, it is possible that the disjunct distribution pattern of Hoplias intermedius , as well as of other examples cited above, results from a common history of these basins.

Goeldi (1898) cited Macrodon intermedius in the Ilha de Marajó, in the mouth of rio Amazonas. Under current understanding of the distribution of H. intermedius it is clear that these records of the species in the Amazon basin were based on misidentifications. The only species of H. lacerdae group occurring in the vicinity of Ilha de Marajó is H. curupira , described in the present study. However, the number of lateral line scales (43) reported by Goeldi (1898) does not match with the range registered for H. curupira (34-39).

Alves & Pompeu (2001), Pompeu &Alves (2003), Vieira et al. (2005) and Silva et al. (2006a) stated that Hoplias aff. lacerdae (= H. intermedius ) was introduced into rio São Francisco because it was originally described from rio Ribeira de Iguape and was missing from earlier ichthyological surveys in the rio São Francisco. The absence of H. intermedius in previous reports of the São Francisco fish fauna is due to the fact that past naturalists failed to recognize two groups of species in that basin based on the orientation of the contralateral dentaries ( Lütken, 2001).This resulted in taxonomic confusion and the placement of H. intermedius in the synonym of H. malabaricus . After these two groups had been formally defined by Oyakawa (1990), Hoplias aff. lacerdae (= Hoplias intermedius ) began to be included in the ichthyological surveys of the rio São Francisco, but was erroneously regarded as an exotic species introduced from the rio Ribeira de Iguape basin.

Although several karyotypes have been reported for the Hoplias malabaricus group (e. g. Bertollo et al., 1983; Dergam & Bertollo, 1990; Bertollo et al., 2000), only one karyotype has been described for specimens of the Hoplias lacerdae group collected in the upper rio Paraná basin ( Bertollo et al., 1978). The diploid number cited by these authors, 2n = 50, is regarded herein as belonging to H. intermedius , as that species occurs in the upper rio Paraná basin. Further karyotype and molecular studies involving Hoplias intermedius from rio São Francisco and rio Doce basins would greatly aid in the knowledge of this species regarding its disjunct distribution.

Hoplias intermedius inhabits main rivers channels and marginal lagoons ( Vieira et al., 2005). Juveniles were captured in floodplain lakes ( Meschiatti et al., 2000). The species is common in reservoirs (e. g. Cunico & Agostinho, 2006; Silva et al., 2006a) and has economic importance (Alves & Pompeu, 2001; Vieira et al., 2005). Its piscivorous habit (Alvim & Peret, 2004) makes it vulnerable to the bioaccumulation of mercury. In the rio das Velhas, a tributary to the rio São Francisco, its flesh had the highest permitted level of mercury (Alves & Pompeu, 2001).

Figures

Fig. 8. Hoplias intermedius, MZUSP 69370, 169.3 mm SL, rio Suaçui Pequeno, Minas Gerais State, Brazil.

Fig. 9. Hoplias intermedius (lectotype of Macrodon intermedius) BMNH 1861.5.16.6, 533.4 mm SL, rio Cipó, Minas Gerais State, Brazil.

Fig. 1. Ventral view of head of (a) Hoplias curupira, MZUSP 24403, 55.5 mm SL; (b) H. curupira, MZUSP 24403, 92.2 mm SL; (c) H. curupira, MZUSP 24403, 162.2 mm SL and (d) H. malabaricus, MZUSP 90416, 101.7 mm SL.

Fig. 3. Map of South America showing geographic distribution of species of the Hoplias lacerdae group based on material examined in this study. Some symbols may represent more than one lot. Numbers indicate type localities of (1) Hoplias australis (squares); (2) H. brasiliensis (losanges); (3) H. curupira (triangles); (4) H. intermedius (dots); and (5) H. lacerdae (inverted triangles).