Brachychalcinus reisi, Garcia-Ayala & Ohara & Pastana & Benine, 2017

Garcia-Ayala, James R., Ohara, Willian M., Pastana, Murilo N. L. & Benine, Ricardo C., 2017, A new species of Brachychalcinus (Characiformes: Characidae) from the rio Xingu basin, Serra do Cachimbo, Brazil, Zootaxa 4362 (4) : -

Brachychalcinus reisi new species

( Figs. 1‒4 )

Holotype: MZUSP 121267 , 56.1 mm SL, Brazil, Pará, Altamira, riO Curuá, 25 Km upstream frOm PCH SaltO dO Curuá , a tributary Of riO Xingu basin, 8º55’46”S, 54º57’38”W, W. Ohara, M. Pastana & O. OyakaWa, 11 Aug 2015 .

Paratypes: All frOm Brazil, Pará, Altamira, riO Curuá, riO Xingu basin. MZUSP 119456, 2, 55.7‒56.9 mm SL ; INPA 53240 , 3 , 52.2 ‒59.0 mm SL, same data as hOlOtype . MZUSP 119107, 2, 38.4‒46.6 mm SL, tributary Of riO Curuá , 8º55’40”S, 54º57’45”W, W. Ohara, M. Pastana & O. OyakaWa, 11 Aug 2015 . MZUSP 119569 , 1 , 30.4 mm SL, igarapé Cintura Fina , near rOad BR-163, 8º53’52”S, 54º59’19”W, W. Ohara, M. Pastana & O. OyakaWa, 11 Aug 2015 . MZUSP 119476, 6, 24.5‒49.2 mm SL, 1 c&s, 51.1 mm SL, igarapé crOssing the rOad On a cattle ranch inside REBIO Nascentes da Serra dO CachimbO, 8°55’46.4”S, 54°57’38.2”W, W. Ohara, M. Pastana & O. OyakaWa, 15 Aug 2015 . MZUSP 119482, 19, 18.2‒56.9 mm SL, 2 c&s, 51.1‒51.5 mm SL, small stream On access frOm rOad BR-163, 8°54’7.2”S, 54°37’48.2”W, W. Ohara, M. Pastana & O. OyakaWa, 7 Aug 2015 . MZUSP 119984, 10, 34.7‒61.3 mm SL, river crOssing a dirt rOad accessed frOm BR-163, 8°54’20.5”S, 54°57’30.8”W, F. DagOsta, M. M. F. MarinhO, P. Camelier & V. GiOvanetti, 7 Aug 2015. LBP 24499, 10, 25.9‒54.6 mm SL; MCP 52550, 3, 31.4‒53.1 mm SL; ZUEC 14759, 2, 32.1‒43.8 mm SL, district Of CachOeira da Serra, riO Treze de MaiO, tributary Of riO Curuá , 8°45’06”S, 55°02’05”W, R. Devidé, A.C. SOutO, N. FlausinO JúniOr, A.C. Dias & C.S. SOuza, 25 Sept 2017, LBP 24500, 0 8, 17.2‒51.3 mm SL, tributary Of riO Curuá , 8°45’54.5”S, 54°59’36.9”W, R. Devidé, A.C. SOutO, N. FlausinO JúniOr, A.C. Dias & C.S. SOuza, 26 Sept 2017.

Non Types: MZUSP 119223, 3, 18.5‒27.3 mm SL, REBIO Nascentes da Serra dO CachimbO, 8°54'23.63"S, 54°35'48.58"W, O. OyakaWa et al., 5 Jul 2015 .

Diagnosis. Brachychalcinus reisi differs frOm all cOngeners by pOssessing a series Of dark, cOnspicuOus, Wavy lOngitudinal stripes On the entire bOdy (vs. lOngitudinal dark Wavy stripes absent Or restricted tO middOrsal pOrtiOn Of bOdy) and by the lOWer number Of lOngitudinal scale rOWs betWeen dOrsal-fin Origin and lateral line (7‒8 vs. 8‒ 12). AdditiOnally, it can be distinguished frOm B. copei (Steindachner, 1883) , B. retrospina BOulenger, 1892 and B. parnaibae by having a lOWer number Of branched dOrsal-fin rays (9 vs. 10‒11). The neW species differs frOm B. nummus Böhlke, 1958 and B. orbicularis (Valenciennes, 1850) by having a lOWer number Of hOrizOntal scale rOWs betWeen the lateral line and pelvic-fin Origin 8‒9 (vs. 10‒11), and further differs frOm B. nummus by having numerOus paralleled arranged scale radii (vs. feW divergent arranged scale radii)

Description. MOrphOmetric data summarized in Table 1. Largest specimen examined 61.3 mm SL. BOdy cOmpressed, shOrt and deep in lateral vieW. Greatest bOdy depth at dOrsal-fin Origin. DOrsal prOfile Of head straight Or slightly cOnvex frOm tip Of snOut tO vertical thrOugh anteriOr nOstril; cOncave frOm that pOint tO tip Of supraOccipital spine. DOrsal prOfile Of bOdy cOnvex frOm supraOccipital spine tip tO dOrsal-fin Origin. PredOrsal pOrtiOn keel slightly cOnvex Or straight alOng dOrsal-fin base; apprOximately straight frOm that pOint tO adipOse-fin Origin, and cOncave betWeen adipOse-fin insertiOn and Origin Of anteriOrmOst dOrsal prOcurrent caudal-fin rays. Ventral prOfile Of head and bOdy cOnvex frOm tip Of dentary tO anal-fin insertiOn. BOdy prOfile alOng anal-fin base straight and pOsterOdOrsally slanted. Ventral prOfile Of caudal peduncle slightly cOncave. Prepelvic regiOn cOmpressed With a median keel.

PredOrsal spine small and rOughly triangular in lateral vieW, With dOrsal prOcess running alOng prOximal pOrtiOn Of first dOrsal-fin ray. First anal prOximal pterygiOphOre triangular, anterOventrally expanded, With lOng fOrWard-directed pOinted prOcess.

JaWs equal; mOuth terminal. Maxilla reaching the vertical thrOugh anteriOr margin Of pupil; With pOsteriOr terminus anteriOr tO third infraOrbital. Maxilla apprOximately at an angle Of 45-50 degrees relative tO lOngitudinal axis Of bOdy. NOstrils clOse tO each Other, anteriOr Opening circular, pOsteriOr Opening crescent-shaped. NOstrils separated by narrOW flap Of skin.

Premaxillary teeth in tWO rOWs; Outer rOW With 3(2), 4*(13), Or 5(4) tricuspid teeth With tip Of cusps directed inWard. Inner rOW With 5*(19) teeth With three tO five cusps each, symphysial tOOth Of inner series narrOW and asymmetric, With fOur cusps. TOOth cusps Of inner premaxillary rOW arranged in semicircular line, directed OutWard. Maxilla With 1(7) Or 2*(12) teeth alOng anterOventral margin, teeth With One tO three cusps. Dentary With 4(19) tri- tO pentacuspid teeth, fOllOWed by a series Of 4 tO 7 small cOnical teeth, cOnsiderably smaller than anteriOr Ones ( Fig. 2 ). Cusps Of large dentary teeth arranged in semicircular line, directed OutWard. Central cusp Of all teeth mOre develOped than lateral cusps.

DOrsal-fin rays iii, 9*(19). First dOrsal-fin element mOdified intO a triangular spine With a sharp backWard prOcess lying On prOximal pOrtiOn Of first unmOdified dOrsal-fin ray ( Fig. 3a ). DOrsal-fin Origin anteriOr tO vertical thrOugh middle Of standard length. AdipOse fin present. PectOral-fin rays i, 10(15), 11*(3), Or 12(2). Tip Of pectOral fin extending slightly beyOnd anteriOr insertiOn Of pelvic fin. Pelvic-fin rays i, 6*(19), tip Of adpressed pelvic fin reaching first anal-fin ray. Pelvic-fin Origin anteriOr tO middle Of standard length. Anal-fin rays iv, 28(6), 29(8), 30*(2), Or 31(3). First anal fin element mOdified intO a triangular spine; secOnd anal-fin element mOdified intO a stiffened simple spine ( Fig. 3b ). Caudal fin With i,9 rays On dOrsal lObe and 8, i rays On ventral lObe. Caudal-fin fOrked, lObes sOmeWhat pOinted and similar in size.

CyclOid scales With numerOus paralell scale radii. PredOrsal line naked. Lateral line With 35(17), 36*(1), Or 37(1) perfOrated scales. Lateral line deflected dOWnWard. LOngitudinal scale rOWs betWeen dOrsal-fin Origin and lateral line 7*(4) Or 8(15). LOngitudinal scale rOWs betWeen lateral line and pelvic-fin Origin 8*(3) Or 9(16). HOrizOntal scale arOund caudal peduncle 14*(19). Single rOW Of 7 tO 15* scales cOvering base Of anteriOr anal-fin rays. Small scales cOvering prOximal tWO-thirds Of caudal-fin lObes.

Vertebrae 34(3). Supraneurals 3(3) With bOny lamellae On upper pOrtiOn. BranchiOstegal rays 4(3). First gill arch With 3(3) hypObranchial, 9(2), Or 10(1) ceratObranchial, 1(3) On cartilage betWeen ceratObranchial and epibranchial, and 10(2) Or 11(1) epibranchial gill-rakers.

Color in alcohol. Overall backgrOund cOlOratiOn Of head and bOdy cream. DOrsal pOrtiOn Of head and bOdy dark. ChrOmatOphOres cOncentrated On snOut, jaWs, dOrsal pOrtiOn Of the neurOcranium and alOng dOrsal midline Of bOdy. Ventral pOrtiOn Of head and bOdy With scattered chrOmatOphOres. InfraOrbital series With chrOmatOphOres scattered On the surface Of infraOrbital bOnes, pigmentatiOn mOre cOncentrated On infraOrbitals 5 and 6. InfraOrbitals, Opercular series, and gular area silvery in specimens retaining guanine. TWO humeral blOtches present, separated by a light area fOrmed by lOW cOncentratiOn Of chrOmatOphOres. First humeral blOtch cOnspicuOus, With dark chrOmatOphOres cOncentrated deeply under scales, rOunded, encOmpassing tWO scales frOm hOrizOntal series and tWO frOm the transverse rOW. SecOnd humeral blOtch faint, With dark chrOmatOphOres scarcely distributed vertically and deeply under scales, extending abOut three scales hOrizOntally and fOur tO five scales vertically. NarrOW lOngitudinal dark line running alOng hOrizOntal septum Of bOdy, extending frOm humeral regiOn tO caudal peduncle. FOurteen tO sixteen, dark, Wavy lOngitudinal stripes fOrmed by dark pigmentatiOn cOncentrated On upper and lOWer scale margins, extending alOng trunk. Stripes visible alOng entire bOdy, mOre discernible dOrsally, except at area Of cOntact betWeen predOrsal series Of scales and first lateral scale rOW. DOrsal dark Wavy stripes mOre cOnspicuOus. Stripes less evident in specimens smaller than 30.0 mm SL. PectOral fin With dark chrOmatOphOres scattered alOng edge Of lepidOtrichia Of unbranched and first branched rays. Pelvic fin With dark chrOmatOphOres lOcated alOng fin rays, pigmentatiOn cOncentrated at pOsteriOr half Of unbranched and first branched rays. PrOximal pOrtiOn Of dOrsal fin With cOncentratiOn Of dark chrOmatOphOres alOng interradial membranes; distal pOrtiOn Of fin With dark chrOmatOphOres On rays and interradial membranes, fOrming a descending dark Oblique stripe. PrOximal pOrtiOn Of anal fin With cOncentratiOn Of dark chrOmatOphOres alOng interradial membranes; distal margin Of fin With chrOmatOphOres On rays and interradial membranes, fOrming an ascending dark stripe. AdipOse fin With scattered dark chrOmatOphOres, mOre cOncentrated at the base Of the fin. Caudal fin With scattered dark pigmentatiOn On margins Of rays. Caudal peduncle blOtch absent.

Color in life. Based On field phOtOgraphs Of three freshly cOllected specimens ( Fig. 4 ). DOrsal pOrtiOn Of head and bOdy yellOW brOWnish. InfraOrbitals and Opercular area silvery. Iris red On upper pOrtiOn, silvery ventrally, anteriOr and pOsteriOr pOrtiOns Of eye With faint green pigmentatiOn. MiddOrsal and ventral pOrtiOns Of bOdy silvery. Dark Wavy stripes visible On flanks, except at regiOn Of anal-fin insertiOn. First humeral blOtch cOnspicuOus. secOnd humeral blOtch incOnspicuOus. DOrsal and adipOse fins Orange. PectOral and caudal fins yellOW. Pelvic and anal fins With yellOW pigmentatiOn restricted tO fin base. DOrsal and anal fins With dark stripe On the distal margin.

Sexual dimorphism. Mature males Of Brachychalcinus reisi exhibit a series Of small bOny hOOks alOng the branched rays Of the dOrsal, pelvic, and anal fins. One c&s male specimen (MZUSP 119569, 51.5 mm SL) presents anal-fin hOOks unevenly distributed alOng the pOsteriOr margin Of the 1st tO the 8th branched rays, mOre numerOus at 3rd anal-fin ray; dOrsal and pelvic-fin hOOks distributed frOm 1st tO 3rd branched rays, With hOOks mOre numerOus On secOnd branched ray. Other types Of sexual dimOrphism, such as differences in standard length Or sexual dichrOmatism, Were nOt detected in B. reisi .

Distribution. Brachychalcinus reisi is knOWn frOm the upper riO Curuá, a left side tributary Of the riO Iriri, at the Serra dO CachimbO, riO Xingu basin, sOuthern Pará State, Brazil ( Fig. 5 ).

Ecological notes. The type lOcality Of Brachychalcinus reisi is lOcated at 467 meters a.s.l., at Serra dO CachimbO, and is a small, black Water stream 3‒5 m Wide, 0.5‒2.5 m deep, With preserved riparian vegetatiOn, mOderate Water current, and bOttOm cOmpOsed mainly by rOck, sand and dead leaves ( Fig. 6 ). In spite Of directed cOllecting effOrts carried Out dOWnstream the falls, the neW species Was Only cOllected upstream great falls (situated at 8º43’58.71”S; 54º57’42.8”W and 8º44’6.09”S; 54º57’42.22”W; and 8º44’59.02”S; 55º02’W and 8º43’34.6”S; 55º01’35”W). Individuals Of Brachychalcinus reisi Were captured at deep pOrtiOns Of the stream. Other species cOllected syntOpically Were Jupiaba kurua Birindelli, Zanata , SOusa & NettO-Ferreira, 2009 and Astyanax cf. elachylepis BertacO & Lucinda, 2005. The analysis Of the stOmach cOntents Of One cleared and stained paratype revealed the presence Of ants, spiders, bees, unidentified insect fragments, and unidentified vegetal matter.

Conservation status. COnsidering that significative threats tO the species Were nOt detected in the area, and that the species Occurs in a prOtected biOlOgical reserve (Reserva BiOlógica Nascente da Serra dO CachimbO), Brachychalcinu s reisi cOuld be classified as Least COncern (LC) accOrding tO the InternatiOnal UniOn fOr COnservatiOn Of Nature (IUCN) categOries and criteria (IUCN Standards and PetitiOns SubcOmmittee, 2014).

Etymology. The specific name reisi is in hOnOr Of RObertO Esser dOs Reis, fOr his great cOntributiOns tO the knOWledge Of the StethapriOninae and the NeOtrOpical ichthyOlOgy as a WhOle. A genitive nOun.

Remarks. AccOrding tO Reis (1989), StethapriOninae is defined by tWO synapOmOrphies: 1) presence Of a bOny, anteriOrly directed spine, preceding the first dOrsal-fin ray; and 2) presence Of very small, thin anal-fin hOOks, varying frOm One tO six per ray segment and facing in all directiOns. HOOks On fin rays Of StethapriOninae are cOmmOnly Observed alOng the pelvic and anal fins, but the presence Of small hOOks On Other than these fins Was sO far undescribed fOr StethapriOninae (see Reis, 1989; Azpelicueta & Garcia, 2000; Malabarba & Weitzman, 2003 fOr a discussiOn On this matter). Aside the hOOks On anal and pelvic fins, mature males Of Brachychalcinus reisi alsO pOssess bOny hOOks On the dOrsal-fin rays. AdditiOnally, an extensive examinatiOn Within stethapriOnins evidenced the presence Of bOny hOOks On dOrsal- and pectOral-fin rays in Poptella compressa (MZUSP 96886) and Poptella longipinnis (INPA 2220). Poptella brevispina (LBP 9332) bears bOny hOOks On all fins. The Occurrence Of bOny hOOks On all fins Of males seems tO be uncOmmOn in characids, Occurring in very feW species ( BertacO & Lucinda, 2006). HOWever, due tO its diminutive nature, bOny hOOks On Other than pelvic and anal fins may have been OverlOOked in several taxa and in fact tO be mOre Widespread in Characidae than presently knOWn.

The upper riO Curuá presents a high level Of fish endemism ( Birindelli et al., 2009; Varella & Sabaj Pérez, 2014). Brachychalcinus reisi seems tO be anOther example Of a taxOn restricted tO this system, althOugh a single knOWn specimen frOm riO Tapajós system (LBP 23315) presents the main diagnOstic characters Of B. reisi (i.e., a series Of dark Wavy lOngitudinal stripes and 7 lOngitudinal scale rOWs betWeen dOrsal-fin Origin and lateral line). This specimen, On the Other hand, differs frOm Brachychalcinus reisi On aspects Of scale radii and by the presence Of scales On the predOrsal line. The scale radii in B. reisi are numerOus and paralleled arranged and cOntrasts tO the very feW and divergent radii present in the specimen frOm riO Tapajós (LBP 23315; Fig. 7 ). Intraspecific variatiOn in scale radii arrangement Was nOt Observed by the authOrs amOng Brachychalcinus species, Or even amOng StethapriOninae species, and in fact seems tO represent a gOOd sOurce Of taxOnOmic infOrmatiOn fOr the subfamily. Relative tO the predOrsal line squamatiOn, B. reisi presents a naked predOrsal line, against an irregularly scaled in the specimen frOm riO Tapajós. COmparisOns amOng stethapriOnins shOWed that full absence Of scales On the predOrsal line is Only Observed in B. reisi and Orthospinus franciscensis (Eigenmann) . TherefOre, it is mOst likely that the specimen frOm riO Tapajós represents a distinct, undescribed species. HOWever, until additiOnal material became available, We tentatively identified this single specimen as Brychychalcinus aff. reisi .

Comparative material examined: All frOm Brazil, except When nOted. Brachychalcinus copei : LBP 18735, 6, 43.5-54.2 mm SL , COlOmbia, Vista HermOsa, Meta . INPA 5667, 3, 44.2‒49.1 mm SL, riO TrOmbetas , Oriximiná, Pará . MZUSP 95808, 12, 41.3‒55.4 mm SL, Itaituba, MatO GrOssO . MZUSP 96026, 19, 41.4‒55.9 mm SL, riO MatrinxÃ, Itaituba, MatO GrOssO . MZUSP 99905, 4, 25.1‒28.2 mm SL, riO Teles Pires , Pará . LBP 192, 24, 26‒61.1 mm SL, riO BrancO basin, Acre . LBP 15070, 31, 20.6‒62.6 mm SL, riO BrancO basin, Acre . LBP 10653, 1, 57.8 mm SL, riO Iquiri , riO BrancO basin, Acre . LBP 7723, 1, 26.8 mm SL, igarapé SÃO FranciscO, Acre . LBP 15070, 31, 20.6‒62.6 mm SL, riO BrancO basin, Acre . Brachychalcinus nummus : LBP 4094, 12, 32.6‒47 mm SL, MânciO Lima, Acre. LBP 12582, 2, 43.6‒45.6 mm SL , Peru, riO MaraÑOn, Nauta, LOretO . LBP 2671, 2, 41.5‒46.2 mm SL, igarapé Santa Maria, riO BrancO, Acre. LBP 17753, 1, 25.9 mm SL , Peru, riO Ucayali, Pucallpa. MUSM 28646, 8, 22.6‒66.9 mm SL , Peru, riO AmazOnas , AndOas, LOretO. Brachychalcinus orbicularis : MZUSP 38559, 2, 38.5‒ 41.9 mm SL , Suriname, MarOWijne, Gran Kreek, 63 km Of AfObaka, BrOkOpOndO District. MZUSP 38269, 2, 31.8‒34.9 mm SL , Suriname, MarOWijne Of Gran Kreek, 63 km Of AfObaka, BrOkOpOndO District . INPA 0 45932, 7, 31.4‒39.7 mm SL, riO Teles Pires, riO Tapajós basin, MatO GrOssO . Brachychalcinus parnaibae : MZUSP 105294, 25, 32.3‒48.7 mm SL, riO Tapirapé , Pará . INPA 39582, 4, 37.4‒41.4 mm SL, riO TOcantins, Pará . MZUSP 36594 , hOlOtype, 63.6 mm SL, LagOs, Serra das COnfusões, riO Parnaíba basin, Piauí. Brachychalcinus retrospina : LBP 8509, 4, 31.3‒43.8 mm SL , Brazil, RiO SalObra , Cáceres, MatO GrOssO . MZUSP 44311, 10, 31.1‒46.3 mm SL, Barra dOs Bugres, afluente dO riO Olímpia , MatO GrOssO . Brachychalcinus aff. reisi : LBP 23315, 1, 65.1 mm SL, Itaituba, Pará . Orthospinus franciscoensis : LBP 10322, 9, 27.6‒40.4 mm SL, riO SÃO FranciscO, lagOa da Tiririca, Minas Gerais . LBP 10442, 23, 30.2‒46.3 mm SL, riO SÃO FranciscO, Minas Gerais ; MZUSP 86913, 11, 32.2‒51.5 mm SL, riO SÃO FranciscO, Três Marias, Minas Gerais . Poptella brevispina : LBP 9332, 28, 54.3‒88.2 mm SL, riO Guamá basin, Pará . LBP 21127, 19, 41.1‒77.5 mm SL, riO OiapOque basin, Amapá . INPA 52824, 5, 53‒68.4 mm SL, riO Xingu basin, Pará . Poptella compressa LBP 3989, 1, 42.7 mm SL, riO Araguaia drainage, SÃO Félix dO Araguaia. LBP 4927, 4, 42.2‒48.4 mm SL, riO Araguaia drainage, Barra dO Garças. LBP 4927, 4, 35.1‒49.8 mm SL, riO Araguaia drainage, Barra dO Garças . MZUSP 89289, 37, 22.2‒43.4 mm SL, riO Araguaia drainage, NOva Crixás, GOiás . MZUSP 117635 , 20 Of 53, 18.3‒39.3 mm SL, riO Madeira drainage, Apuí . MZUSP 119369, 6, 26.36‒45.41 mm SL, riO Curuá , Serra dO CachimbO, Pará . INPA 52827 , 20 Of 40, 37.6‒61.9 mm SL, riO Xingu , Pará. Poptella longipinnis : LBP 3060, 14, 34.8‒42.3 mm SL , Venezuela, riO OrinOcO basin. INPA 2220, 4, 49.6‒ 43.1 mm SL, riO TOcantins, Pará . Poptella paraguayensis : LBP 5793, 14, 21.4‒49.2 mm SL, riO Mirim , MatO GrOssO . LBP 10778, 7, 28.1‒34.2 mm SL, RibeirÃO dOs VeadOs, COxim, MatO GrOssO dO Sul . LBP 13447, 13, 27.1‒37.8 mm SL, riO Cuiabá , POcOné, MatO GrOssO . LBP 5114, 11, 32.6‒40.2 mm SL, riO Cuiabá , POcOné, MatO GrOssO . LBP 3826, 15, 32.6‒40.2 mm SL, riO NegrO, Aquidauana, MatO GrOssO dO Sul . INPA 2026, 2, 42.6‒44.5 mm SL, riO Paraguai, MatO GrOssO . LBP 8492, 2, 21‒21.8 mm SL, riO Paraguai, Cáceres, MatO GrOssO . LBP 13554, 1, 33.9 mm SL, riO CaracarazinhO dO MOnO, POcOné, MatO GrOssO . Poptella sp.: LBP 7829, 5, 37.3‒ 27.2 mm SL, COcalinhO, riO Araguaia drainage, MatO GrOssO . LBP 7201, 1, 36.9 mm SL, riO Araguaia drainage, Barra dO Garças , MatO GrOssO . Stethaprion crenatum : INPA 3776 , 2 Of 16, 73‒ 75.7 mm SL, riO Madeira , POrtO VelhO, ROndônia . INPA 3776 , 2 Of 16, 73‒ 75.7 mm SL, riO Madeira , POrtO VelhO, ROndônia. Stethaprion erythrops : LBP 12583, 2, 43.1‒47.1 mm SL , Peru, riO MaraÑOn, Nauta, LOretO . INPA 33381 , 1 , 54 mm SL, riO Madeira , POrtO VelhO, ROndônia . INPA 28924 , 1 , 77.2 mm SL, riO Juruá drainage, AmazOnas .

Figures

FIGURE 2. Brachychalcinus reisi, MZUSP 119476, paratype, 51.1 mm SL, medial view of right side, premaxillary, maxillary and dentary.

FIGURE 3. Brachychalcinus reisi, MZUSP 119482, paratype, 54.1 mm SL, lateral view of left side. a) Modified dorsal fin element.b) modified anal-fin elements.

FIGURE 5. Map of the upper rio Xingu basin and adjacent upper Tapajós basin, showing the distribution of Brachychalcinus reisi. White dot represents type locality, dark triangles remaining localities.Symbols may represent more than one locality.

FIGURE 6. Type-locality of Brachychalcinus reisi, Brazil, Pará, Altamira, upper rio Curuá, rio Xingu basin.

FIGURE1. Brachychalcinus reisi, MZUSP 121267,holotype, 56.1 mm SL, Brazil, Pará, Altamira, rio Curuá,rio Xingu basin.

FIGURE4. Brachychalcinus reisi, MZUSP 119456,paratype, 57.3 mm SL, Brazil, Pará, Altamira, rio Curuá, rio Xingu basin.

FIGURE7. Formof radii on the scales:(a) Brachychalcinus aff.reisi, LPB 23459;(b)Brachychalcinus reisi, MZUSP 119482.