Hemigrammus lunatus Durbin, 1918

Ota, Rafaela P., Lima, Flávio C. T. & Pavanelli, Carla S., 2014, A new species of Hemigrammus Gill, 1858 (Characiformes: Characidae) from the rio Madeira and rio Paraguai basins, with a redescription of H. lunatus, Neotropical Ichthyology 12 (2), pp. 265-279 : 270-274

Hemigrammus lunatus Durbin, 1918

Figs. 4-7

Hemigrammus lunatus Durbin in Eigenmann, 1918: 164 [type locality: “ Amazon basin”, restricted herein to “ Brazil, Amazonas , Codajás , lago Badajós (ca. 03º21’S 62º41’W)”; see below; “ Obidos ”, “ Caceres ”, “ Jauru ”].

Hyphessobrycon maxillaris Fowler, 1932: 354 [type locality: “ Descalvados ”, rio Paraguai basin, Mato Grosso, Brazil].

Hemigrammus maxillaris . Weitzman, 1985: 808 [new combination].

Diagnosis. Hemigrammus lunatus differs from most congeners, except from H. barrigonae , H. machadoi , and H. ulreyi , by possessing a wide dark horizontal stripe across the eye (vs. Distribution. Hemigrammus machadoi is known from the upper rio Paraguai basin, from the rio Guaporé and some other smaller tributaries of the rio Mamoré and rio Madeira, on the upper and middle portions of the rio Madeira basin in Brazil ( Fig. 3 ). Comparisons between Hemigrammus machadoi specimens from rio Guaporé, rio Pacaás Novos and upper rio Paraguai basins revealed no differences in morphometric, meristics or color pattern, and the data of these distinct populations are pooled together in the description and Table 1 .

Ecological notes. Specimens of Hemigrammus machadoi are typically found in slow flowing, low-gradient streams and small rivers, with clear, sometimes slightly dark-stained waters, as the upper rio Guaporé and the type locality, the igarapé Barreiro. River bottom at those sites was constituted mainly of sand and clay. Aquatic vegetation was abundant at the igarapé Barreiro and at some sites at the rio Guaporé and H. machadoi seemed to prefer its surroundings. The species was also captured in clear water wetlands, adjacent to the rio Guaporé. Analyses of dissected specimens (MZUSP 95365) collected in November revealed two mature females, 26.6-27.2 eye stripes absent or, when present, vertical in the remaining congeners). It can be distinguished from most congeners, with the exception of H. barrigonae , H. boesemani , H. geisleri , H. machadoi , H. mimus , and H. ulreyi , by the possession of a well defined narrow dark stripe at the basis of the anal fin (vs. dark stripe at the basis of anal fin absent). Hemigrammus lunatus can be easily distinguished from H. boesemani , H. geisleri , and H. mimus , by possessing a distinct roundish dark humeral blotch (vs. humeral blotch absent) and by lacking a blotch on caudal peduncle or any distinct patch of pigmentation on caudal fin (vs. blotch on caudal peduncle present in H. boesemani and H. geisleri , a dark marking present at the basis of each caudal-fin lobe basis in H. mimus ). Hemigrammus lunatus can be distinguished from H. barrigonae and H. ulreyi by lacking a narrow, well-defined longitudinal dark stripe (vs. present), and by lacking a discrete blotch on caudal peduncle (vs. present in H. barrigonae ) or a dark pigmentation patch on the basis of anteriormost dorsalfin rays (vs. present in H. ulreyi ). It can be diagnosed from H. machadoi , the most similar congener by having a small roundish dark humeral blotch, extending horizontally from fourth through sixth lateral-line scales, and vertically from fourth through fifth scale rows above lateral line (vs. conspicuous, vertically elongated humeral blotch, extending horizontally from second through sixth lateral-line scales, and vertically from third row above lateral line to first row below it), and by having 6-7 gill-rakers on upper branch and 11-12 on lower (vs. 4-5, and 9-10, respectively). Additionally, the lower number of cusps of inner premaxillary, dentary, and maxillary largest tooth (5 vs. 5-7 cusps, mode 7, in premaxillary and dentary; 1-3 vs. 3-5, mode 5, in maxillary), and total vertebrae (32-33 vs. 34-35) helps to distinguish H. lunatus from the new species.

Description. Morphometric and meristic data summarized in Table 2 . Body compressed, moderately elongated; greatest body depth located anteriorly to dorsal-fin origin. Dorsal profile of head convex from tip of snout to anterior naris, straight to slightly concave from latter point to tip of supraoccipital spine. Dorsal profile of trunk moderately convex from tip of supraoccipital spine to dorsal-fin origin; inclined from latter point to adipose-fin origin and slightly concave along caudal peduncle. Ventral profile of body convex from tip of lower jaw to anal-fin origin; inclined along anal-fin base. Ventral profile of caudal peduncle slightly concave.

Jaws equal, isognathous; mouth terminal. Maxillary slightly curved; posterior terminus surpassing vertical through anterior margin of eye. Small ossification anterior to first unbranched ray present in all 11 c&s specimens examined. Distal margin of dorsal fin straight. Dorsal-fin origin at midbody or slightly behind this point; base of posterior most dorsal-fin ray slightly behind vertical through anal-fin origin. First dorsal-fin pterygiophore insertion posterior to neural spine of tenth vertebra. Adipose fin small. Pelvic-fin origin ahead of vertical through dorsal-fin origin; tip of longest ray surpassing anal-fin origin. Anal fin falcate, last unbranched ray to fourth branched ray longest, with remaining rays decreasing gradually in size towards anal-fin end; last anal-fin pterygiophore insertion behind hemal spine of fifteenth caudal vertebrae (11). Caudal-fin scales covering about one-third of upper and lower caudal lobes, mainly arranged on upper and lower caudal lobes margins, gradually decreasing in size. Caudal fin bifurcated; lobes slightly pointed, almost equal in size, inferior lobe slightly longer than superior. Precaudal vertebrae 12-13; caudal vertebrae 20(11); total vertebrae 32(5) or 33(6). Supraneurals 3(3), 4(7), or 5(1). Branchiostegal rays 4(11).

Color in alcohol. Overall ground coloration of body light tan. Anterior portion of lower jaw, snout, and dorsal portion of head with dense concentration of small dark chromatophores, imparting an overall dark color. Gular area and infraorbitals clearer; third infraorbital and opercle silver in specimens retaining guanine pigmentation. Tip of maxillary, opercle and fourth and fifth infraorbital with scattered, relatively large dark chromatophores. Eye with broad dark longitudinal midlateral stripe (not discernible in specimens retained for a long period in formalin). Longitudinal dark stripe along midline of body present, very faint and narrow, originating after dark humeral blotch and extending up to approximately vertical through middle of caudal peduncle or slightly behind this point. Scales from dorsal region of body posteriorly bordered with dark chromatophores, conferring a moderately developed reticulate pattern. Dark humeral blotch conspicuous, small, roundish, with well-defined contour, extending from fourth through sixth lateral-line scales, and vertically from fourth through fifth scale rows above lateral line. Dark chromatophores arranged along margins of hypaxial muscles bundles from area above anal fin to caudal peduncle. Dorsal fin mostly hyaline, with few dark chromatophores concentrated along unbranched rays and third branched rays and its interradial membranes. Adipose, pectoral and pelvic fins almost hyaline, with few dark chromatophores scattered mainly along their distal margins.Anal fin hyaline, with few dark chromatophores usually concentrated on its unbranched rays and interradial membranes, forming a dark narrow margin. Anal fin with narrow, conspicuous dark stripe along anal-fin base. Caudal fin hyaline, its main external rays with few dark chromatophores along their margin. Caudal spot absent ( Fig. 7 ).

Color in life. Based on a picture of a freshly collected specimen from Manso Reservoir, upper rio Paraguai basin, and freshly collected specimens from the rio Amazonas near Santarém, Pará (ZUEC 7995). Overall coloration pattern light yellow or clear. Gular region, opercle, infraorbital bones, and abdominal with silver hue. Tip of dentary, snout and top of head light brown, with yellow tinge. Dorsal, pelvic, anterior portion of anal and caudal fins, and adipose fin yellow to light orange, translucent in the specimens from rio Amazonas. Dark midlateral stripe faint, plumbeous, extending into caudal peduncle ( Fig. 5 ).

Sexual dimorphism. As previously mentioned by Lima & Sousa (2009: 162), mature males of Hemigrammus lunatus bear anal- and pelvic-fin hooks. Fin hooks were observed in males collected from November through April. Pelvic-fin hooks are anterodorsally arranged almost all over the entire length of all fin rays; usually one pair of hooks per ray segment. The anal fin bears 5-15 tiny hooks, anterodorsally arranged almost over the entire length of the last unbranched ray and first three or four branched fin rays, one pair per ray segment.

Habitat and ecological notes. Habitat preferences are somewhat similar to those presented by Hemigrammus machadoi . Thus H. lunatus is commonly found in slow flowing, low-gradient streams and small rivers. In fact, both species are found syntopically at some localities on the rio Guaporé basin. However, H. lunatus has a substantially broader distribution than H. machadoi and occurs in habitats where the latter species is unknown, as floodplain lakes associated with white-water rivers in central Amazon. At the río Napo basin in Amazonian Ecuador, H. lunatus was found to be an ubiquitous and abundant species found in lagoons and riverine habitats across a piedmont/lowland river stretch ( Galacatos et al., 1996, 2004).

Analyses of dissected specimens, captured from November through April, from both rio Madeira and rio Paraguai basins, revealed mature females ( INPA 21621 , 2 ex.; NUP 2114 , 1 ex.; NUP 7531 , 2 ex.; NUP 7533 , 4 ex.; NUP 8024 , 15 ex.), possessing large yellowish oocytes, and mature males ( INPA 21621 , 1 ex.; NUP 2113 , 1 ex.; NUP 2114 , 2 ex.; NUP 7531 , 6 ex.; NUP 7533 , 4 ex.; NUP 8024 , 5 ex.) with lobulated, whitish testicles .

Distribution. Hemigrammus lunatus is known from the central and western portions of the rio Amazonas basin, in Brazil, Bolivia (e.g., Géry, 1964; Chernoff et al., 2000), Peru (e.g., Géry, 1964, Barthem et al., 2003), Ecuador (e.g., Galacatos et al., 1996), and Colombia (e.g., Mojica et al., 2005), and along rio Paraguai basin in Brazil and Paraguay. The species is also recorded from the upper Corantijn River in Suriname, near the boundary with Brazil ( Géry, 1965; Mol, 2012) and from the upper río Orinoco and río Caura in Venezuela ( Lasso et al., 2004). The map shows the localities of the material examined in the present study ( Fig. 6 ). For comments on the identity of the remaining populations, see “Remarks”.

Remarks. Hemigrammus lunatus was described by Durbin (in Eigenmann, 1918: 164-165), though the name had previously appeared without a description or diagnosis in Eigenmann (1910: 436) and Ellis (1911: 162). Although paratypes of Hemigrammus lunatus were collected both from the rio Paraguai (Jauru and Cáceres) and Amazon basins (Óbidos), no information on the locality of the holotype was provided at the description, and the type locality is indicated simply to be “Amazon basin” by Durbin (in Eigenmann, 1918: 165). However, the holotype and the two paratypes (one paratype is missing), that belong to the same lot (MCZ 20964) actually have not lost their locality data ( Figs. 4 and 6 ). The holotype and these two paratypes were collected at the lago Badajós, a large blocked-valley lake tributary of the rio Solimões/ Amazonas near Codajás, Amazonas (ca. 03º21’S 62º41’W). We therefore restrict the type locality of Hemigrammus lunatus to “ Brazil, Amazonas, Codajás, lago Badajós (ca. 03º21’S 62º41’W)”. Although the holotype is mixed with two paratypes in the same lot, the largest specimen was designated by Durbin (in Eigenmann, 1918) as the “type” of the species. Notwithstanding we have not examined material collected at the type locality, lago Badajós lies about 260 km in a straight line upstream from the lago Janauacá, a very similar blocked-valley lake from where much material of the species is available in collections (see Material examined). Géry (1964: 9-10) provided a short redescription of the species based on specimens from the Amazon basin in Peru and Bolivia considered that the population of H. lunatus occurring in the rio Paraguai basin might be distinct at the subespecific level, since the comparison of the specimens from the Amazon basin with a single specimen from the rio Paraguai basin in Paraguay showed the latter to be more elongated, and displaying a narrower infraorbital 3 and a longer maxillary. Géry (1964: 10) even suggested that Hyphessobrycon maxillaris might be an available name for that purported subspecies. The examination of extensive material from the Central Amazon, rio Madeira, and rio Paraguai basins during the present study did not reveal any features that might distinguish these different populations, and thus they are herein considered to represent a single species ( Fig. 7 ). We have examined very few specimens of H. lunatus from western Amazon other than from the rio Madeira basin and for the moment we refrain from discussing their presumable conspecificity with the populations from Central Amazon, rio Madeira, and rio Paraguai basins. Records of H. lunatus from the upper Corantjin River in Suriname ( Géry, 1965; Mol, 2012) and rio Orinoco basin in Venezuela ( Lasso et al., 2004) need to be reexamined. For a discussion on the synonym of Hyphessobrycon maxillaris , see the Discussion.

Material examined. Type specimens: Hemigrammus lunatus: CAS 42679, paratype, 1, 23.8 mm CP; MCZ 20964, holotype, 1, 26.5 mm SL, paratypes, 2, 21.7-23.9 mm SL, Codajás, lago Badajós, ca. 3º21’S, 52º41’W . Non-type specimens: Brazil: Amazonas State, rio Negro basin: INPA 15339 , 1 , 36.8 mm SL, Manaus, igarapé Tarumãzinho, road BR-174, km 28 rio Tarumã-Açu , 02º43’51”S 60º04’46”W . Rio Solimões basin: MZUSP 100860 , 1 , 23.4 mm SL, Manaus, rio Amazonas , lago Puraquequara, ca. 03º02’S 59º49’W ; INPA 24765 , 2 , 24.5-26.4 mm SL ; NUP 8023 , 8 , 23.2 -27.0 mm SL, Careiro da Várzea, ilha Marchantaria , ca. 03º14’S 59º56’W ; MZUSP 101287 , 1 , 24.4 mm SL, Careiro da Várzea, ilha Marchantaria , lago Camaleão, ca. 03º14’S 59º56’W ; MZUSP 100794 , 1 , 24.5 mm SL, Careiro da Várzea, ilha Marchantaria , ca. 03º14’S 59º56’W ; NUP 8024 , 21 (16, 25.5-29.9 mm SL) ; NUP 9573 , 4 c&s, 25.8-29.3 mm SL, Manaquiri, lago Murumuru, lago Janauacá system, 03º25’43”S 60º16’00”W ; MCP 37131, 2 , 23.0- 23.4 mm SL, Manaquiri, lago Murumuru, lago Janauacá system, 03º25’43”S 60º16’00”W ; MCP 37151, 3 , 19.0- 23.2 mm SL, Manaquiri, lago Murumuru, lago Janauacá system, 03º25’43”S 60º16’00”W ; MCP 43956, 19 , 22.8- 26.1 mm SL, Manaquiri, lago Murumuru, lago Janauacá system, 03º25’43”S 60º16’00”W ; MCP 37149, 2 , 26.6-27.5 mm SL, Manaquiri, paraná de Janauacá, mouth of lago Castanho, 03º24’S 60º16’W ; MZUSP 102965 , 1 , 23.8 mm SL, Manaquiri, lago do Castanho, São José, lago Janauacá system, 03º24’S 60º16’W ; MZUSP 102737 , 1 , 26.0 mm SL, Manaquiri, parana de Janauacá, mouth of lago Castanho, 03º24’S 60º16’W ; MZUSP 102722 , 2 , 24.0- 26.9 mm SL, Manaquiri, lago Murumuru, lago Janauacá system, ca. 03º24’S 60º16’W ; MZUSP 102980 , 7 , 22.2-29.8 mm SL, Manaquiri, channel between lago Murumuru and paraná de Janauacá, 03º24’S 60º16’W ; MZUSP 102730 , 16 , 23.8-33.1 mm SL, Manaquiri, lago Murumuru, lago Janauacá system, ca. 03º24’S 60º16’W ; MZUSP 102754 , 9 , 19.5-31.4 mm SL, Manaquiri, channel between lago Murumuru and paraná de Janauacá, ca. 03º24’S 60º16’W ; MZUSP 100463 , 1 , 30.1 mm SL, Manaquiri, lago do Castanho, São José, lago Janauacá system, 03º24’S 60º16’W . Pará State: ZUEC 7995 (103, 19.7-28.0 mm SL), Santarém, lago do Pajaú (or Tamoatá), rio Amazonas , 2º11’29”S, 54º51’28”W . Rondônia State: INPA 21621 , 17 , 25.9- 33.2 mm SL ; INPA 22571 , 7 , 27.5-30.2 mm SL, Guajará-Mirim, rio Pacaás-Novos , 10º52’S 65º16’W ; INPA 39569 , 5 , 23.3-27.5 mm SL, Guajará-Mirim, middle rio Cautário, tributary of rio Guaporé , 10°59’05”S 62°56’12”W . Rio Madeira basin, Mato Grosso State: MCP 45041, 36 , 20.5-31.1 mm SL, Comodoro, stream tributary of rio Novo ( rio Guaporé basin), road BR-174, 14º13’26’’S 59º41’27’’W ; MCP 45022, 18 , 24.0- 32.3 mm SL, Pontes e Lacerda, rio Pindaituba (tributary of rio Guaporé ), BR-174, 15º00’41’’S 59º17’18’’W ; MCP 45030, 6 , 28.6-31.4 mm SL, Pontes e Lacerda, stream tributary of rio Guaporé , road BR-174, 14º55’15’’S 59º17’29’’W ; MCP 15724, 6 , 20.8-26.2 mm SL ; MZUSP 44457 , 5 , 20.8-22.9 mm SL, Pontes e Lacerda, rio Guaporé and flooded areas, 15º12’S 59º21’W ; MCP 45036, 24 , 24.7-36.8 mm SL, Pontes e Lacerda, rio Bugre (tributary of rio Guaporé ), BR-174, 14º51’35’’S 59º17’57’’W ; MCP 45993, 1 , 29.5 mm SL, Pontes e Lacerda, stream tributary of rio Pindaituba , road BR-174, 14º59’53’’S 59º17’10’’W ; MCP 45994, 23 , 21.5- 28.8 mm SL, Nova Lacerda, rio Galera (tributary of rio Guaporé ), balneário Galera, 14º28’59’’S 59º35’07’’W ; MZUSP 95364 , 33 , 21.9-30.5 mm SL, Vila Bela da Santíssima Trindade, rio Guaporé , 15º00’28”S 59º57’22”W . Rio Paraguai basin: Mato Grosso State : MCP 15726, 24 , 23.2-32.5 mm SL, stream at road Barra do Bugres / Cáceres, 99 km south of Barra do Bugres , tributary of rio Paraguai, ca. 15º45’S 57º20’W ; MCP 15731, 7 , 27.1-31.2 mm SL ; MZUSP 44338 , 7 , 27.1-28.5 mm SL, stream at Porto Estrela, road Barra do Bugres / Cáceres, 35 km south of Barra do Bugres , tributary of rio Paraguai, 15º24’S 57º15’W ; MCP 15733, 11 , 24.5-31.8 mm SL, Barra dos Bugres, rio Jauquara (tributary of rio dos Pássaros) at Jauquara, ca. 15º10’S 57º05’W ; MZUSP 44358 , 24 , 25.4 -33.0 mm SL, stream crossing the road Barra do Bugres / Cáceres, about 90 km from Barra do Bugres , tributary of rio Paraguai, ca. 15º43’S 57º22’W ; MZUSP 44481 , 3 , 27.0- 30.9 mm SL, rio Sangradouro, at road Cáceres / Cuiabá about 90 km east from Cáceres , ca. 16º14’S 56º37’W ; MZUSP 44473 , 1 , 31.8 mm SL, Cáceres, ribeirão das Flexas, road Cáceres / Cuiabá, 69 km E Cáceres, ca. 16º09’S 57º21’W ; MZUSP 44285 , 2 , 27.7 -30.0 mm SL, Jangada, ribeirão Chiqueirão, 21 km W Jangada, tributary of rio Jangada , ca. 15º07’S 56º39’W ; MZUSP 90076 , 12 , 22.2 -31.0 mm SL, Cáceres, rio Sepotuba , near its mouth, 15º53’34’’S 57º38’44’’W ; MZUSP 90142 , 11 , 19.8-28.3 mm SL, Cáceres, mouth of rio Sepotuba , 15º54’53”S 57º39’24”W ; MZUSP 90196 , 11 , 17.7- 29.4 mm SL, Cáceres, lower rio Sepotuba , 15º47’33”S 57º39’20”W ; MZUSP 90274 , 41 , 26.1-31.6 mm SL, Cáceres, lower rio Sepotuba , 15º46’07”S 57º38’54”W ; MZUSP 90475 , 7 , 25.7-32.2 mm SL, Cáceres, lower rio Sepotuba , 15º43’53’’S 57º39’53’’W ; MZUSP 90498 , 6 , 26.9-30.1 mm SL, Cáceres, rio Sepotuba (middle portion), 15º28’44’’S 57º41’59’’W ; MZUSP 90481 , 2 , 26.6-32.3 mm SL, Cáceres, rio Sepotuba (middle portion), 15º31’01’’S 57º42’26’’W ; MZUSP 4443 , 3 , 21.9-22.3 mm SL, Santo Antônio do Leverger, rio Cuiabá system ; NUP 969 , 2 , 27.1-28.5 mm SL, Barão de Melgaço, rio Cuiabá , 16º20’02”S 55º57’10”W ; NUP 2112 , 1 , 35.9 mm SL, Rosário Oeste, córrego Imbaúba, tributary of rio Cuiabá , 14º55’06”S 56º27’02”W ; NUP 2113 , 2 , 21.2-22.7 mm SL, Rosário Oeste, córrego São Joaquim, tributary of rio Cuiabá , 14º44’58”S 56º07’39”W ; NUP 2114 , 3 , 28.5-34.2 mm SL ; NUP 7528 , 5 , 22.7-26.1 mm SL, Barão de Melgaço, córrego Cancela, tributary of rio Cuiabá , 14º42’30”S 56º15’51”W ; NUP 9574 , 4 c&s, 27.3-32.4 mm SL, Rosário Oeste, córrego Cancela, tributary of rio Cuiabá , 14º42’30”S 56º15’51”W ; NUP 2115 , 7 , 25.8-28.6 mm SL, Chapada dos Guimarães, rio Quilombo , tributary of Manso Reservoir, 15º06’50”S 55º40’38”W ; NUP 9548 , 3 c&s, 19.3-27.2 mm SL, Chapada dos Guimarães, rio Quilombo , tributary of Manso Reservoir, 15º06’50”S 55º40’38”W ; NUP 7527 , 1 , 30.7 mm SL, Chapada dos Guimarães, rio Casca , tributary of Manso Reservoir, 14º57’07”S 55º42’59’ W. Mato Grosso do Sul State: MZUEL 5414 , 5 , 23.2-33.2 mm SL, Corumbá, bridge on corixo Sará, Estrada Parque, 19º00’29”S 57º39’08”W ; MZUEL 5415 , 1 , 25.5 mm SL, Corumbá, Base de Estudos do Pantanal ( BEP), right margin of rio Miranda , 19º34’37”S 57º00’42”W ; MZUEL 5416 , 1 , 24.8 mm SL, Corumbá, Estrada Parque, 9 km from Base de Estudos do Pantanal ( BEP), 19º30’45”S 57º02’27”W ; MZUSP 59467 , 10 , 25.8-30.8 mm SL, Corguinho, stream at Chacara da Portela, tributary of rio Aquidauana , 19º48’40’’S 54º50’39’’W ; NUP 9881 , 1 , 28.7 mm SL, Porto Murtinho, riacho Amonguijá, tributary of rio Paraguai, 21º41’16”S 57º52’55”W . Paraguay. Concepción: MZUSP 54028 , 55 , 26.2-39.9 mm SL, riacho Blandengue, near mouth with río Apa , 22º14’00”S 57º21’00”W ; MZUSP 54027 , 21 , 29.9-38.9 mm SL, Arroyo La Paz , below bifurcation of the mouth of Riacho Primavera, 22º24’S 57º43’W ; MZUSP 54354 , 3 , 32.6-33.3 mm SL, Alto Paraguay, río Paraguay, marginal lagoon, estancia Cerrito, 21º27’00”S 57º55”00”W. Canindeyú: MNHNP 3246 , 14 (13, 19.5- 36.8 mm SL), oxbow lake of río Jejuí-Mí, 1 km from headquarters of Reserva Natural del Bosque Mbaracajú , 24º08’27”S 55º38’25”W ; MNHNP 3619 , 4 , 29.9-36.5 mm SL, río Jejuí-Mí, Reserva Natural Del Bosque Mbaracajú , Puesto Jejuí-Mí, 24º08’27”S 55º38’25”W .

Figures

Fig. 4. Hemigrammus lunatus: MCZ 20964, (a) holotype, 26.5 mm SL; (b) paratype, 21.7 mm SL, and (c) paratype, 23.9 mm SL; Brazil, Amazonas State, Codajás, lago Badajós, tributary of rio Solimões.

Fig. 5. Hemigrammus lunatus, NUP 2112, 35.9 mm SL, Brazil, Mato Grosso State, Rosário Oeste, córrego Imbaúba, tributary of rio Cuiabá, rio Paraguai basin.

Fig. 6. Map of northern South America showing distribution of Hemigrammus lunatus: (1) the white circle represents the type locality of Hemigrammus lunatus, (2) the gray circle represents the type locality of Hyphessobrycon maxillaris, and black circles represent remaining localities of analysed material in the present study.

Fig. 7. Hemigrammus lunatus: both from Brazil, (a) MZUSP 102730, 33.1 mm SL, female, Amazonas State, Manaquiri, lago Janauacá system; (b) MZUSP 90475, 30.2 mm SL, male, Mato Grosso State, Cáceres, rio Sepotuba, rio Paraguai basin; Hyphessobrycon maxillaris (c)ANSP 53660, holotype, 28.3 mm SL, Brazil, Mato Grosso State, Descalvados, rio Paraguai basin.

Fig. 3. Map of northern South America showing distribution of Hemigrammus machadoi. The white circle represents the type locality, black circles represent the paratypes localities, and the gray circles represent the non-types localities.