First report of four characiform fishes ( Ostariophysi : Characiformes ) for Uruguay

In this article the authors present the first report of four characiform fish species for Uruguay, extending their current distribution to the middle and lower Uruguay River basin: Astyanax saguazu Casciotta, Almirón and Azpelicueta, 2003; Hypobrycon poi Almirón, Casciotta, Azpelicueta and Cione, 2001; Leporinus amae Gody, 1980; Cyphocharax saladensis (Meinken, 1933). These species were previously recorded from either the upper Uruguay River, Patos-Merín lagoon system or Paraná River. Color pattern in life for A. saguazu and H. poi are described for the first time. 1 Museo Nacional de Historia Natural, Departamento de Zoología, Sección Ictiología. 25 de Mayo 582. CP. 11000. Montevideo, Uruguay. 2 Universidad de la República, Facultad de Ciencias, Departamento de Ecología y Evolución, Sección Zoología Vertebrados. Iguá 4225. CP 11400. Montevideo, Uruguay. 3 Appalachian State University, Biology Department. NC 28608. Boone, North Carolina, NC, USA 4 Current Address: Auburn Univeristy, Department of Biological Sciences. AL 36849. Auburn, Alabama, USA. 5 Universidad de la República, Facultad de Ciencias, Departamento de Ecología y Evolución, Grupo de Ecología y Rehabilitación de Sistemas Acuáticos. Tacuarembó entre Saravia y Bvar. Artigas. CP 20000. Maldonado, Maldonado, Uruguay. 6 Aarhus University, Department of Bioscience. Vejlsøvej 25, Silkeborg 8600, Denmark. * Corresponding author. E-mail: serraelbicho@gmail.com Wilson S. Serra 1,2*, Matías Zarucki 2, Alejandro Duarte 2, Edward D. Burress 3,4, Franco Teixeira-deMello 5, Iván González-Bergonzoni 5,6 and Marcelo Loureiro 2,1 First report of four characiform fishes (Ostariophysi: Characiformes) for Uruguay Recent taxonomic and revisionary work in ichthyological collections and field surveys of Uruguay, have resulted in the description of new species for science (e.g. González–Bergonzoni et al. 2010; Loureiro et al. 2011), new records for the country and confirmation of some doubtful records (Zarucki et al. 2010; Serra et al. 2011; Serra et al. 2012). In the present paper we present four new records of characiform fishes in Uruguay, with the first descriptions of color pattern in life (before fixation) for Astyanax saguazu and Hypobrycon poi. Specimens are housed in the collection of Facultad de Ciencias (ZVC-P), Museo Nacional de Historia Natural de Montevideo (MHNM), Montevideo, Uruguay; Fundación Miguel Lillo (CI-FML), San Miguel de Tucumán, Argentina, and the Auburn University Museum (AUM), Alabama, USA. Identifications were based on original diagnoses or revisionary works. Measurements (nearest 0.1 mm) are straight-line distances taken with a digital caliper. Standard length (SL) is measured from tip of snout to hypural joint, and the head length (HL) does not include the opercular flap. When needed, specimens were cleared and counterstained (C&S) following Dingerkus and Uhler (1977). Astyanax saguazu Casciotta, Almirón and Azpelicueta, 2003 (Figure 1): Recorded specimens present all the diagnostic characters proposed by Casciotta, Almirón and Azpelicueta (2003): Two or three maxillary teeth, third or fourth tooth of outer premaxillary series inserted posteriorly to the rest, large eye (41-45% HL), first anal-fin ray inserted anterior to last dorsal-fin ray, iv-vi, 25-29 anal-fin rays, and 37-39 perforated scales in lateral line series. Color in live specimens: body silver-gray with a horizontal silver midlateral stripe; pectoral fins yellowish, dorsal, adipose and pelvic fins yellow, anal fin yellow with anterior border reddish, and caudal fin yellow with outer rays reddish; humeral spot dark and vertically elongated; caudal peduncle spot black, extending into middle caudal fin rays; dorsal surface of head and body brownish, and upper region of iris dark red. Specimens were collected in the middle and upper Cuareim River in Artigas Department, and in the upper Arapey River in Salto Department (Appendix 1 and Figure 5). Figure 1. Live (ZVC-P 11585) and preserved (ZVC-P 11586) specimens of A. saguazu. Scale bar represent 1 cm. Photos by W. S. Serra. Hypobrycon poi Almirón, Casciotta, Azpelicueta and Cione, 2001 (Figure 2): Recorded specimens present the synapomorphic characters proposed for the genus by Silva and Malabarba (1996): dentary tooth anteriorly directed and inserted along the anterior margin of the bone; anterior tip of the dentary truncated forming an antero-dorsal bony

First report of four characiform fishes (Ostariophysi: Characiformes) for Uruguay Recent taxonomic and revisionary work in ichthyological collections and field surveys of Uruguay, have resulted in the description of new species for science (e.g.González-Bergonzoni et al. 2010;Loureiro et al. 2011), new records for the country and confirmation of some doubtful records (Zarucki et al. 2010;Serra et al. 2011;Serra et al. 2012).In the present paper we present four new records of characiform fishes in Uruguay, with the first descriptions of color pattern in life (before fixation) for Astyanax saguazu and Hypobrycon poi.
Specimens are housed in the collection of Facultad de Ciencias (ZVC-P), Museo Nacional de Historia Natural de Montevideo (MHNM), Montevideo, Uruguay; Fundación Miguel Lillo (CI-FML), San Miguel de Tucumán, Argentina, and the Auburn University Museum (AUM), Alabama, USA.Identifications were based on original diagnoses or revisionary works.Measurements (nearest 0.1 mm) are straight-line distances taken with a digital caliper.Standard length (SL) is measured from tip of snout to hypural joint, and the head length (HL) does not include the opercular flap.When needed, specimens were cleared and counterstained (C&S) following Dingerkus and Uhler (1977).
Color in live specimens: body silver-gray with a horizontal silver midlateral stripe; pectoral fins yellowish, dorsal, adipose and pelvic fins yellow, anal fin yellow with anterior border reddish, and caudal fin yellow with outer rays reddish; humeral spot dark and vertically elongated; caudal peduncle spot black, extending into middle caudal fin rays; dorsal surface of head and body brownish, and upper region of iris dark red.
Specimens were collected in the middle and upper Cuareim River in Artigas Department, and in the upper Arapey River in Salto Department (Appendix 1 and Figure 5).Recorded specimens present the synapomorphic characters proposed for the genus by Silva and Malabarba (1996): dentary tooth anteriorly directed and inserted along the anterior margin of the bone; anterior tip of the dentary truncated forming an antero-dorsal bony   lamina, posterior to the posterior tooth insertion; and wide and shortened maxilla, enlarged where in contact with the premaxila.Morphometric data and color pattern in formalin preserved specimens partially overlap the known variation for H. maromba and H. poi, however, mouth position at lower orbital margin and presence of a vertically elongated humeral spot (sub-rounded only in a few exemplars), correspond to H. poi.The species was collected in three localities in northern Uruguay: Cuareim River in Artigas Department (middle Uruguay river basin), Tacuarembó Chico River in Tacuarembó Department (Negro River basin), and Queguay River in Paysandú Department (lower Uruguay River basin), (Appendix 1 and Figure 5).
Color in live specimens: Body silver-gray with a horizontal silver band and sky-blue highlights; pectoral fins hyaline, yellowish in the anterobasal portion, and with black chromatophores in the anterior and posterior margins of rays, conspicuous in the first ray; pelvic fins hyaline, white in the anterior margin; dorsal, adipose and caudal fins yellow; anal fin hyaline with dispersed black an red chromatophores, and anterior border white; humeral spot dark; spot in caudal fin base black, less conspicuous than specimens in alcohol, extending into middle caudal fin rays; dorsal surface of head and body yellowish, and upper region of iris dark.
Leporinus amae Godoy, 1980 (Figure 3): Recorded specimens present the characters proposed by Almirón et al. (2013).We found this species in three localities of middle and upper Cuareim River (Appendix 1 and Figure 5).
Color in live specimens: Color patterns in our specimens are the same as described by Almirón et al. (2013).In some of our specimens the yellow background in de body and the red color in cheeks, are more intense than the observed in specimens of the cited article.
Cyphocharax saladensis (Meinken, 1933) (Figure 4): Specimens present the diagnostic characters proposed by Vari (1992) for the species: 27 to 30 scales in the longitudinal scale series including the lateral line, absence of longitudinal dark stripes or spots on the body, dorsal fin without dark pigmentation, and caudal peduncle with a patch of chromatophores, 13 or 14 pectoral fin rays, 8 or 9 perforated scales on lateral line, and body dept 39-43% of SL.Present records are from Cuareim River in Artigas Department, Negro River in Durazno Department and middle Uruguay River in Río Negro Department (Appendix 1 and Figure 5).
Color in live specimens: Color patterns in our specimens are similar to those described by Malabarba et al. (2013), though some specimens present a bright golden background color in the body.
The present records extend the known distribution of these four species, and are the first records in Uruguay.
Astyanax saguazu and Hypobrycon poi were previously known as highly endemic from a small area of Misiones, Argentina (reported from only three and two localities, respectively), (Almirón et al. 2001;Casciotta et al. 2003;Chatellenaz 2007).However, the present records reveal a more extensive distribution range for both species.present record extends its distribution 450 km south to the middle Uruguay River basin.In contrast, Cyphocharax saladensis, is widely distributed in the la Plata River basin and Patos-Merín lagoon system, in Argentina, Brazil and Paraguay (Azpelicueta and Braga 1991;Vari 1992).
Considering their restricted distribution range in Uruguay (criteria in Soutullo et al. 2009), we argue that these species should be included in the list of prioritary species for conservation of the national wildlife protected areas system: SNAP (Sistema Nacional de Areas Protegidas) (see Soutullo et al. 2009).According to these and previous records (Zarucki et al. 2010;Serra et al. 2011) the Cuareim River basin seems to be the southernmost distribution of several species from the upper and middle Uruguay River Basin.Additionally, the Cuareim River supports an ecologically diverse and functionally important fish assemblage (Burress et al. 2012).Thus, conservation of this ichthyological diversity is important, especially because there are no protected wildlife areas in this basin.Particularly considering that the Cuareim River is being affected by an increasing agricultural activity, such as irrigation dams construction (ca.402) that contribute to habitat fragmentation, coupled with high water demands that can exceed water availability in the basin (Collischonn et al. 2011).Given these poor environmental circumstances, the critical location of the basin along the middle Uruguay River, and the ecologically important fish assemblages, we judge that the Cuareim river drainage must be considered for the national conservation program.
Similarly, Leporinus amae was known from the upper Uruguay River basin in the States of Santa Catarina and Rio Grande do Sul, Brazil (Godoy 1980; Hermes-Silva et al. 2009; Oliveira-Nuñer and Zaniboni-Filho 2009), and State of Misiones, Argentina (Almirón et al. 2013), and theAcknowledgments: We are grateful to Jordan M. Holcomb and Federico Quintans for their assistance with fieldwork, and to Mr. Bergós for allowing us to work on his land.We thank Daniel Hernandez Huidobro and Fabrizio Scarabino for comments on the manuscript, Luiz Malabarba (UFRGS) for photographs of live specimens of L. amae, and Mercedes Azpelicueta (Museo de La Plata) for the copy of the description of H. poi.We also thank two anonymous reviewers that notoriously improved the manuscript.This article was partially funded by the Paul V. Loiselle Conservation Fund, Appalachian State University Office of Student Research grant, CSIC, and Programa de Desarrollo Tecnológico (Proyecto: 71/08).M.L. is funded by Sistema Nacional de Investigadores and PEDECIBA (Programa de desarrollo de las Ciencias Básicas).