Taxonomic study of Moenkhausia cotinho Eigenmann, 1908 and Hemigrammus newboldi (Fernández-Yépez, 1949) with the description of two new species of Moenkhausia (Teleostei: Characiformes: Characidae) Author Mathubara, Kleber 0000-0002-9891-0875 kleber. leite @ usp. br; https: // orcid. org / 0000 - 0002 - 9891 - 0875 kleber.leite@usp.br Author Toledo-Piza, Mônica 0000-0001-7596-1410 mtpiza @ usp. br; https: // orcid. org / 0000 - 0001 - 7596 - 1410 mtpiza@usp.br text Zootaxa 2020 2020-09-14 4852 1 1 40 journal article 8541 10.11646/zootaxa.4852.1.1 d56e60ac-9956-4908-a6a4-21e344ee0f41 1175-5326 4408176 301C1BCC-51F1-43E0-9774-85DC28741E10 Hemigrammus newboldi ( Fernández-Yépez, 1949 ) ( Figs. 18–19 ) Ramirezella newboldi Fernández-Yépez, 1949: 2 [original description; type locality: “Palital, Edo. Guárico , Venezuela ”]; Géry, 1977: 487 [identification key] Moenkhausia cotinho (not of Eigenmann): Géry, 1964: 5 , fig. 2 [identification key; diagnosis; Río Ucayali basin]; Flores , 1995: 21 , table 5 [listed; Perú ]; Géry & Mahnert, 1984: 177 , fig. 7 [as aff. Moenkhauisa cotinho ; short description; Peru , Loreto : Río Mangua (trib. Río Napo); Cocha Yuracyacu, Río Samiria] Hemigrammus newboldi Géry, 1977: 458 , 487 [in key and diagnosis]; Ortega & Vari, 1986: 9 [listed; Perú ] (identification based on distribution); Taphorn, 1992: 221 [similarity with Moenkhausia cotinho ; description; identification key; Venezuela : Río Apure ]; Lima et al. , 2003: 146 [listed]; Hoeinghaus et al., 2004: 91 , appendix 2 [listed; Venezuela : Río Portuguesa ]; Machado-Allison, 2006: 25, table 3 [listed; Venezuela ]; Lasso et al. , 2009: 131 [listed, Venezuela , Río Orinoco]; Rivero & Rojas, 2013: 84 , appendix 2 [listed; Venezuela , Orinoco]; Lasso et al. , 2014: 112 [listed; distribution; Colombia , upper Orinoco, Casiquiare, Ventuari, Meta , Cinaruco, Capanaparo, Apure, Caura, Caroní, Morichal Largo, Delta]; Trujillo et al. , 2016: 104 , 112 [listed; Colombia , Río Meta basin, figure] Diagnosis. Hemigrammus newboldi is distinguished from all congeners, except H. hyanuary Durbin , H. schmardae (Steindachner) , H. levis Durbin and H. vorderwinkleri Géry , by the presence of a single humeral blotch and a blotch on the base of the caudal fin (vs. humeral blotch absent or presence of two humeral blotches, and blotch on caudalfin base absent). It differs from H. hyanuary , H. schmardae and H. vorderwinkleri in having more perforated scales along the lateral line (9 to 16 vs. 6–9 respectively). It is distinguished from Hemigrammus levis by the deeper body (27.2– 37.5% vs. 22.9–29.8% SL) and the shorter longitudinal stripe extending from the vertical through the dorsalfin origin to the caudal peduncle (vs. longitudinal stripe extending from the humeral spot to the caudal peduncle) and by the absence of hooks on the anal-fin rays of mature males (vs. mature males with hooks on the anal fin rays). FIGURE 18. Hemigrammus newboldi , shortly after collection, not preserved, Venezuela, Río Caquetá. (Photo: Nathan Lujan). FIGURE 19. Hemigrammus newboldi , neotype, MZUSP 96431, 38.7 mm SL, Venezuela, Bolivar, Caicara del Orinoco, Río Orinoco, Puerto Cedeño. Description: Morphometric data presented in Table 4 . Body compressed, moderately elongate. Largest specimen examined 46.8 mm SL; greatest body depth slightly anterior to dorsal-fin origin. Dorsal profile of head and body convex from snout tip to dorsal-fin origin. Profile along base of dorsal fin straight and inclined posteriorly; moderately convex to adipose fin; concave along dorsal margin of caudal peduncle. Ventral profile of head and body convex from anterior tip of dentary to anal-fin origin; straight along anal-fin base; concave along ventral margin of caudal peduncle. Mouth terminal, jaws equal. Posterior tip of maxilla anterior to vertical through middle of orbit. Premaxillary teeth in two rows. Outer row with 4*(30) or 5(11) tricuspid teeth, inner row with 5* (30) tri- to pentacupid teeth. Dentary with 4*(41) large pentacuspid teeth followed by a series of 7(3) diminutive conical teeth ( Fig. 20 ). Central median cusp of all teeth longer than lateral cusps. First gill arch with 3(2) rakers on hypobranchial, 12(2) rakers on ceratobranchial, 1(2) on intermediate cartilage, and 7(2) rakers on epibranchial. TABLE 4 . Morphometric data of Hemigrammus newboldi . N= Number of specimens, NT= neotype (MZUSP 96431), SD= standard deviation. Standard length in mm.

N	NT	Range	Mean	SD
Standard length	107	38.7	22.4–46.8	33.5	–
Percents of standard length
Depth at dorsal-fin origin	106	13.3	27.5–37.5	32.6	2.3
Snout to dorsal-fin origin	106	55.0	43.6–59.1	54.9	1.7
Snout to pectoral-fin origin	104	28.4	26.1–31.7	28.7	1.1
Snout to pelvic-fin origin	105	49.3	46.2–53.0	49.7	1.4
Snout to anal-fin origin	104	71,3	66.4–73.9	70.0	1.8
Eye to dorsal-fin origin	106	41.3	37.7–44.2	41.3	1.3
Dorsal-fin origin to caudal-fin base	106	33,9	40.8–49.2	45.7	1.7
Dorsal-fin length	105	27.1	23.4–32.0	27.4	1.3
Dorsal-fin base length	106	11.8	9.1–16.4	14.1	1.3
Pectoral-fin length	104	27.6	17.4–33.0	26.3	2.1
Pelvic-fin length	105	19.6	16.7–26.1	19.6	1.5
Anal-fin length	103	27.3	18.3–30.0	27.2	1.5
Anal-fin base length	105	21.9	18.7–26.8	23.2	1.5
Caudal-peduncle depth	106	12.4	8.9–13.4	11.2	0.9
Caudal-peduncle length	105	9.3	8.7–16.5	11.3	1.4
Head length	105	25.8	24.5–29.4	26.2	0.9
Percents of head length
Snout length	105	22.0	18.1–29.2	24.7	1.9
Horizontal eye diameter	105	38.0	36.7–45.9	40.5	1.9
Interorbital width	105	37.0	18.1–29.2	24.7	1.7
Upper jaw length	105	35.0	28.7–43.0	35.2	3.2

Supraneurals 4(3), obliquely oriented anteriorly. First supraneural anterior to neural spine of fifth vertebra, fourth supraneural between neural spines of seventh and eighth vertebrae. Origin of dorsal fin at approximately half of SL, first pterygiophore of dorsal fin anterior to neural spine of ninth vertebra. Dorsal-fin rays ii, 8(8), 9(82) or 10(12); supernumerary dorsal-fin rays 1(3). Origin of anal fin at approximately 2/3 of SL, first pterygiophore of anal fin anterior to haemal spine of 18 th vertebra. Anal fin falcate, anal-fin rays iv, 15(2), 16(2), 17(18), 18*(31), 19(34), 20(17), or 21(1). Pectoral fin i, 10(3), 11(22), 12*(42), 14(30), or 15(5), tip of longest pectoral-fin ray not extending beyond base of innermost pelvic-fin ray. Pelvic-fin origin anterior to vertical through dorsal-fin origin. Pelvic-fin origin anterior to vertical through dorsal-fin origin. Pelvic-fin rays i, 7*(103), longest pelvic-fin ray reaching urogenital opening. Caudal fin forked, principal caudal-fin rays on dorsal lobe i, 9(3), and on ventral lobe i, 8(3), dorsal procurrent caudal-fin rays 9 (3), ventral procurrent caudal-fin rays 9(3). Adipose fin anterior to vertical through base of posteriormost anal-fin ray. Scales cycloid, with 6(2) or 7(2) radii moderately diverging posteriorly to margin of exposed field of scale; conspicuous circulii present dorsally and ventrally of radial field and continuous anteriorly on embedded portion of scale ( Fig. 7D ). Axillary scale present behind pectoral and pelvic fins. Proximal one third of caudal-fin lobes covered by small scales. Lateral line incomplete, pored scales with 9(1), 10(1), 11(20), 12(8), 13(1), 14(10), 15*(1) or 16(2), total of scales from immediately posterior of supracleithrum to base of caudal fin 28(3), 29(12), 30(17), 31(14), 32*(9), or 33(2). Predorsal scales 9(1), 10*(21), or 11(10). Middorsal scales between base of posteriormost dorsal-fin ray and adipose-fin 7(2), 8(60), 9(18). Longitudinal scale rows between dorsal-fin origin and lateral line 5*(93), longitudinal scale rows between lateral line and pelvic-fin origin 2(1), 3*(93), 4(1). Circumpeduncular scales 12(7), 13(21), 14*(20), 15(2). Total vertebrae 25(3): precaudal vertebrae 12(3), caudal vertebrae 13(3). Color in alcohol. Overall ground coloration of head and body tan. Dorsal portion of head and body slightly darker than ventral portion. Infraorbitals 5 and 6 and opercular region with scattered chromatophores. Predorsal and preadipose scales dark, forming a longitudinal line along midline of body. Scales of three dorsalmost longitudinal series of body with few chromatophores along posterior margin, but not resulting in reticulate pattern. Humeral blotch vertically elongate, with dorsal portion covering horizontally approximately two scales and extending vertically on scales of three longitudinal rows. Ventral portion of humeral blotch somewhat faded compared to dorsal. A longitudinal stripe extending from vertical through dorsal-fin origin to caudal peduncle; stripe silvery on specimens that retain guanine on body, dark on other specimens. A dark rounded blotch on base of middle caudal fin rays, with pigmentation reaching to tip of middle caudal-fin rays in many specimens; dark pigmentation extending from caudal blotch to base of dorsal and ventralmost principal caudal-fin rays. Caudal blotch preceded by light area on caudal peduncle. Caudal fin with light spot on each lobe, posterior to area of dark pigmentation. Dorsal, anal, adipose, pectoral and pelvic fins mostly hyaline with few scattered chromatophores ( Fig. 19 ). FIGURE 20. Premaxilla, maxilla and dentary of Hemigrammus newboldi , INHS 40141, 42.7 mm SL. Right side, medial view. Scale bar = 1 mm. Color in life. Based on a photograph of one specimen shortly after collection, and a picture of a live specimen from Trujillo et al. (2016: 104) . Ground coloration of dorsolateral region of head and body yellowish to olive; ventrolateral region of head and body silvery. Dorsolateral region of head and body yellowish to slightly orange. Dark pigmentation pattern of coloration in life similar to that described specimens except that humeral blotch is marked in preserved specimens due to presence of guanine on body and caudal spot rounded, A silvery longitudinal stripe extending from vertical through dorsal fin to caudal peduncle. Middle portion of caudal fin rays, base of dorsal fin, and adipose fin; anterior anal-fin yellowish or orange ( Fig. 18 ). Distribution. Hemigrammus newboldi occurs in drainages of the upper portion of the Amazon basin and in the Río Orinoco basin in Colombia and Venezuela , in 9 of the regions proposed by Dagosta & de Pinna (2017) for the Amazon and neighboring regions (17. Juruá, 18. Ucayali, 19. Marañon-Nanay, 20. Napo-Ambyiacu, 21. Putumayo, 22. Japurá, 39. Lower Orinoco, 40. Upper Orinoco, 41. Apure ) ( Fig. 21 ). FIGURE 21. Map of central and northern South America showing geographic distribution and locality of neotype (red star) of Hemigrammus newboldi . Remarks. Ramirezella newboldi was described by Fernández-Yépez (1949) as a new genus and species from the drainage of Río Apure , Río Orinoco basin, Venezuela . Later, Taphorn (1992: 221) claimed that there were no characters to justify the proposition of a new genus, and although suggesting that Ramirezella should be considered a synonym of Hemigrammus , the author also mentioned that H. newboldi could be included in the genus Moenkhausia , based on its similarity with M. cotinho which, according to Eigenmann (1917) , presented a gradation from incomplete to complete lateral line. As discussed above (see Geographic variation under the account of Moenkhausia cotinho ), specimens of M. cotinho presents a complete lateral line throughout its distribution range, except from a few specimens from the Guyana . In addition, H. newboldi differs from M. cotinho in the relatively longer pectoral fin, with the tips of the longest rays extending beyond the pelvic-fin origin (vs. tips of pectoral-fin rays reaching at most the pelvic-fin origin), in the presence of conical teeth in the posterior portion of the dentary (vs. teeth tricuspid); in the absence of a reticulate color pattern of body (vs. reticulate color pattern of body present); and in the shorter longitudinal dark stripe on body, that extends from the vertical through the dorsal-fin origin to the caudal peduncle (vs. longitudinal stripe extending from the humeral spot to the caudal peduncle). Rivero & Rojas (2013) , Trujillo et al. (2016) , and DoNascimento et al. (2017) reported H. newboldi for Amazon and Orinoco drainages in Colombia . We did not examined specimens listed by those authors, however the identification is herein confirmed based on their descriptions and figures. The type specimens of many species described by Fernandez-Yépez have been reported to be either lost or not found ( Vari, 1989 ; Chernoff et al. , 1994 ). Recent efforts, in the year of 2012, have failed to find the holotype of H. newboldi (Rafaela Ota., pers. comm., December 2019 ). In view of the historical taxonomic uncertainties concerning the distinction between H. newboldi and M. cotinho and from other species described recently, the specimen from lot MZUSP 96431 is herein designated as neotype of H. newboldi , following article 75.3.1 of the ICZN (1999). Type material : MZUSP 96431 ( 38.7 mm SL), Venezuela , Bolivar , Río Orinoco , Puerto Cedeño , 7°39’06”N 66°10’34”W , M. de Pinna & H. Hernandez , 20 Jul 2004 . Neotype of Ramizerella newboldi by present designation. Non-type material : Brazil : Acre : Acre , rio Juruá basin: ZUEC 13156 (3-6, 22.9–37.4 mm SL), lake of rio Juruá , near Praia Grande , Cruzeiro do Sul , 7°40’32”S 72°9’34”W , F.C. T . Lima , T . C. Pessali , T . R . F. Jacó & A. Casas , 25 Sep 2016 ; ZUEC 13366 (3-3, 33– 34.2 mm SL), rio Moa , beach near mouth, Cruzeiro do Sul , 7°39’34”S 72°41’07”W , F.C. T . Lima , TC. Pessali , T . R . F. Jacó , A. Casas & T . L. Silva , 27 Sep 2016 ; ZUEC 17245 (9-9, 22– 23.3 mm SL), Igarapé Preto , Cruzeiro do Sul , T . R . F. Jacó , A. Casas . Peru : Loreto : Loreto , Río Amazonas basin: ANSP 136965 (2-2, 34.4–43.7 mm SL), vicinity of Iquitos , Río Nanay , well above Morona Cocha, M . Hohn ( Catherwood Peru Expedition ), 19 Oct 1955 ; ANSP 178414 (1-1, 31.8 mm SL), Río Amazonas , large sandy beach just upstream from mouth of Río Yanuyacu , 4°14’1”S 73°19’14”W , M. Sabaj , M. Littmann , J. Stewart , N. Lovejoy , M. Thomas , K. Elkin , S. Curran , L. Isuiza , 11 Aug 2001 ; INHS 39271 (5-5, 30– 33.8 mm SL), Loreto , Mayuruna Cocha ( Río Orosa Dr. ) ca. 30 min. by boat downstream of Dept . Loreto , M. Sabaj , J. Armbruster , 13 Aug 1996 ; INHS 39329 (4-4, 30.6–31.2 mm SL), Loreto , Río Yanashi ( Río Amazonas Dr. ) Yanashi , 69.8 mi E Iquitos , M. Sabaj , J Armbruster , 14 Aug 1996 ; INHS 39684 , (1-1, 25.7 mm SL), Caño Sacarito ( Río Orosa Dr. ) ca. 35 min upstream by boat from Loreto , Loreto , M.H. Sabaj & J.W. Armbruster , 13 Aug 1996 ; INHS 40141 (10-10, 39.5–46.2 mm SL), Río Orosa ( Río Amazonas Dr. ) mouth of Tonche Caño , Madre Selva II field 69.4 mi E Iquitos bearing 267º, Loreto , M. Sabaj , J. Armbruster & M. Hardman , 12-13 Aug 1996 ; INHS 53808 (1-1, 31.4 mm SL), Río Napo (rio Amazonas Dr. ) opposite Mazán. N Channel Río Napo , Loreto , M. Sabaj , M. Littmann , 30 Jul 1999 ; INHS 43325 (1-1, 40.4 mm SL), Río Itaya (trib. Río Amazonas ) 11 km SSW center of Iquitos, J . Armbruster, M . Sabaj , 6 Aug 1997 ; Ucayali : Ucayali , Río Ucayali basin: ANSP 112258 (1-1, 29.5 mm SL), lower Río Ucayali ; Yanacu Cocha , near mouth of Río Pacaya from Puinahua, K.H . Lüling ; Loreto : ANSP 178140 (1-1, 27.5 mm SL), Río Napo ( Río Amazonas Dr. ) beach & blackwater along right bank just upstream from mouth R . Mazan , near town of Mazan , Loreto , 3°29’10”S 73°6’24”W , M.H. Sabaj , M. Littman , N. R . Elkin ; MZUSP 26243 (11-11, 31.6–36.3 mm SL), Yarinacocha , Pucallpa , Prov. Cel. Portillo , H. Ortega , 23 Sep 1977 ; Venezuela , Amazonas , Río Orinoco basin: INHS 29078 (1-1, 31.7 mm SL), Río Mavaca ( Río Orinoco Dr. ), L. Nico & F. Morillo , 25-31 Jan 1991 ; INHS 31488 (4-4, 26.8–28.7 mm SL), Río Tigre ( Río Orinoco Dr. ) 50 km SSE Maturin. Rt. 10 bridge Monagas , D.C. Taphorn & L.M. Page , 8 Jan 1994 ; INHS 34415 (4-7, 34.8–36.2 mm SL), Río Aguaro ( Río Orinoco DR.) P.N. Aguaro - Guariquito en. Laguna , D. Taphorn , L.M. Page , P.A. Ceas , 11 Jan 1995 ; Apure , Río Apure basin: INHS 27746 (1-1, 22.4 mm SL), Caño Maporal ( Río Apure - Río Orinoco Dr. ), L.M. Page , B.M. Burr , P.A. Ceas , 4 Jan 1992 ; INHS 28106 (10-10, 26.2–32.1 mm SL), Caño Guaritico (= Caño Maporal ) Río Apure - Río Orinoco Dr. ), L. Page , B. Burr , P. Ceas , C. Taylor , S. Walsh & A. Barbarino , 4 Jan 1992 ; INHS 28167 (1-1, 28.2 mm SL), tributary. Río Doradas ( Río Apure - Orinoco Dr. ) , Tachira , L. Page , B. Burr , P. Ceas , 06 Jan 1992 ; INHS 28167 (1-1, 28.5 mm SL), Trib. Río Doradas ( Río Apure Río Orinoco Dr. ) La Pedrera, L . Page, B . Burr , P. Caes , 6 Jan 1992 ; INHS 60312 (1-1, 37.1 mm SL), Caño Guaritico ( Río Apure-Río Orinoco Dr. ), L. Page , P. Ceas & A. Barbarino , 17 Dec 1990 ; Bolivar , Orinoco basin: INHS 89787 (9-10, 34.1–39.3 mm SL), Caño Cicara ( Río Matiyure - Río Apure - Río Orinoco ) ca. 15 km SSW Manfecal on Bruzual , J. Armbruster , M. Hardman , 28 Dec 1999 ; Guarico , Río Orinoco basin: INHS 89851 (2-2, 34.9–37.3 mm SL), Caño Guarico ( Río Orinoco ) ca. 38 km S. Bruzual on Rd. to Elorza, J.W . Armbruster, M . Hardman , 29 Dec 1999 .