Serrapinnus kriegi ( Schindler, 1937 )

Serra, Wilson S., Scarabino, Fabrizio & Paullier, Sofía, 2018, First record of Serrapinnus kriegi (Schindler, 1937) and confirmed presence of S. calliurus (Boulenger, 1900) for Uruguay (Characiformes: Characidae), Ichthyological Contributions of PecesCriollos 59, pp. 1-6 : 4-5

Serrapinnus kriegi ( Schindler, 1937) (fig. 2)

o Cheirodon kriegi Schindler, 1937 *: 106 [description]

o Serrapinnus kriegi ( Schindler, 1937) : Malabarba, 1998 *: 215 [new combination]; Miquelarena et al., 2008*: 74 [identification key, redescription and distribution]; Mantinian, 2011 *: 50, 84 [identification key, redescription, pictures and distribution]

o Serrapinnus sp. (partim): Loureiro et al., 2013: 104, 110 [species list and conservation]

Examined material (12 lots): MHNM 3560 , 7 ex., 18,5-23,4 mm SL, Paso de León (30º08'12,11''S; 27º06'14,73''W), Cuareim River, Artigas Department, Uruguay, col.: W.S. Serra, M. Zarucki, M. Loureiro & D. Arrieta, 22/III/2014 . MHNM 3794 , 1 ex., 21,0 mm SL, Paso de la Cruz (30°16'19.50"S; 57°19'12.72"W), Cuareim River , Artigas Department, Uruguay, col.: W.S. Serra, M. Loureiro, F. Teixeira de Mello, S. Villars, D. Olsson, N. Zaldúa & F. Stábile, 26-27/IX/2015 . MHNM 4004 , 3 ex., 12,3-19,9 mm SL (fixed in 95% Ethanol), pond near Uruguay River (31°04'19,98"S; 57°51'32,83"W), Villa Constitución , Salto Department, Uruguay, col.: W.S. Serra & J. Chocca, 20/IV/2017 . MHNM 4006 , 7 ex., 11,4-21,1 mm SL (fixed in 95% Ethanol), Rincón de Franquia (30°11'45,75"S; 57°37'08,40"W), Bella Unión, Artigas Department, Uruguay, col.: W.S. Serra, R. Foti & J. Chocca, 22/IV/2017 . ZVC-P 10398 , 1 ex., 18,8 mm SL, Cañada del Sauzal de la Divisa (30°19'54,09"S; 57°25'30,08"W), Artigas Department, Uruguay, col.: M. Loureiro, F. Teixeira de Mello, I. González-Bergonzoni & F. Quintans, III/2007 . ZVC-P 14042 , 6 ex., 20,4-23,3 mm SL, Arrocera CONTI in front of Isla del Zapallo (30°30'00,03"S; 57°51'24,97"W), Uruguay River , Artigas Department, Uruguay, col.: C. Ríos & J. González, 01/VII/1979 . ZVC-P 14188 , 6 ex., 17,2-22,7 mm SL (fixed in 95% Ethanol), Franquia (30°12'34,26"S; 57°37'29,76"W), Bella Unión, Artigas Department, Uruguay, col.: M. Loureiro, J. Bessonart, M. Zarucki & S. Paullier, 18/VIII/2017 . ZVC-P 14189 , 3 ex., 17,1-18,1 mm SL (fixed in 95% Ethanol), Laguna Redonda (30°13'09,38"S; 57°37'20,32"W), Bella Unión, Artigas Department, Uruguay, col.: M. Loureiro, J. Bessonart, M. Zarucki & S. Paullier, 17/VIII/2017 . ZVC-P 14192 , 3 ex., 17,6-19,1 mm SL, Laguna Redonda (30°13'09,38"S; 57°37'20,32"W), Bella Unión, Artigas Department, Uruguay, col.: M. Loureiro, J. Bessonart, M. Zarucki & S. Paullier, 17/VIII/2017 . ZVC-P 14194 , 2 ex., 17,9-23,9 mm SL, Franquia (30°12'34,26"S; 57°37'29,76"W), Bella Unión, Artigas Department, Uruguay, col.: M. Loureiro, J. Bessonart, M. Zarucki & S. Paullier, 18/VIII/2017 . ZVC-P 14196 , 1 ex., 21,9 mm SL, Arroyo Yucutujá (30°20'49,42"S; 57°19'43,00"W), Artigas Department, Uruguay, II/2006 . ZVC-P 14197 , 4 ex., 21,4-22,3 mm SL, Arroyo del Cortado (30°08'56,34"S; 57°05'55,34"W), Artigas Department, Uruguay, col.: A. Duarte, W.S. Serra & M. Loureiro, 5/XII/2012 .

This species differs from other congeners from the La Plata River basin by the following combination of characters: premaxillary teeth with 7-9 cusps, dorsal fin hyaline, incomplete lateral line, abdominal black spot present and procurrent rays of the ventral profile of the caudal peduncle anteriorly curved ( Almirón et al., 2015; Jerep & Malabarba, 2014; Malabarba & Jerep, 2014; Mantinian, 2011; Miquelarena et al., 2008).

Uruguayan specimens present all these characters and come from Artigas and Salto Departments, in northern Uruguay, associated to the Uruguay River and its affluent, the Cuareim River (fig. 3). They were collected in shallow lagoons, canals and wetlands, occasionally forming schools with S. calliurus . Previously known distribution of S. kriegi extended through Paraná, Paraguay and Middle Uruguay (Rio Grande do Sul) River basins, in Argentina, Bolivia, Brazil, and Paraguay ( Bertaco et al., 2016; Mantinian, 2011; Malabarba, 2003; Miquelarena et al., 2008; Sarmiento et al., 2014).

On the basis of material analyzed we confirm the presence of S. calliurus in shallow lagoons, canals and wetlands mainly in the north of the country. Additionally we record for the first time for Uruguay the presence of S. kriegi in the same area and habitats of S. calliurus , occasionally even forming mixed schools. Fieldwork in other areas of the country suggests that these species are mainly restricted to the area herein reported, matching the distribution of other species as Apistogramma borellii , Diapoma alegretense , Lepthoplosternum pectoralis , Leporinus lacustris , Tatia boemia , and Microglanis aff. eurystoma ( Zarucki et al., 2010) . The historical presence of both species in Uruguay was confirmed through material deposited in collections since almost 50 years. This fact reinforces the relevance of scientific collections and the periodic conservation of large lots of "species", that may reveal to be species complexes only lately detected after new analyses.