Hisonotus candombe, a new species from the rio Uruguay basin in the Repüblica Oriental del Uruguay (Siluriformes, Loricariidae, Otothyrini) Jorge R. Casciotta, M. de las Mercedes Azpelicueta, Adriana E. Almirön & Thomas Litz Casciotta, }., M. de las M. Azpelicueta, A. Almirön & T. Litz (2006): Hisonotus candombe, a new species from the rio Uruguay basin in the Repüblica Oriental del Uruguay (Siluriformes, Loricariidae, Otothyrini). -Spixiana 29/2: 147-152 Hisonotus candombe, spec. nov. is described from arroyos Palomas and Catalän Grande, rio Uruguay basin, in the Repüblica Oriental del Uruguay. Hisonotus can-dombe is distinguished by the following combination of characters: presence of heavy serrae along complete posterior pectoral spine margin, presence of narrow odontodes free area along anterior margin of snout, 5 anal-fin branched rays, lat-eral line canal incomplete and discontinuous with an anterior field bearing 2-7 pores and posterior field with 8-19 pores. Dr. Jorge R. Casciotta (investigador CIC), Dra. M. de las Mercedes Azpelicueta, Dra. Adriana E. Almirön; Division Zoologia Vertebrados, Museo de La Plata, Paseo del Bosque, 1900 La Plata, Argentina; e-mail:
[email protected] Dr. Thomas Litz, Krumpfhalde 47, D-88448 Attenweiler, Germany; e-mail:
[email protected] Introduction Methods Since the original description of Hisonotus by Eigen-mann & Eigenmann (1889), many species of this genus have been considered as species of the genera Otocinclus or Microlepidogaster : Subsequently, Schae-fer (1998) redefined the genus Hisonotus based on the absence of plates anterior to nostrils and the presence of rostral plates with large odontodes and proposed the inclusion of several species of Micro-lepidogaster and Otocinclus within the genus Hisono-tus. In southern South America, about 13 species of the genus were found in the rivers Paraguay, Paranä, Uruguay, and Rio de la Plata, and Los Patos System. Only two of them are present in the Uruguay river basin, H. ringueleti Aquino et al., 2001 and H. macu-lipinnis (Regan, 1912). The objective of the present contribution is the description of a new species of Hisonotus from the rio Uruguay basin in the Repüblica Oriental del Uruguay. Specimens were cleared and counterstained following Taylor & Van Dyke (1985). Measurements were taken as straight line distances using digital callipers follow-ing Boeseman (1968). Counts include holotype and 11 paratypes; values of the holotype are indicated by an asterisk. Vertebrae count includes those ones corre-sponding to the Weberian apparatus and the caudal centrum (CU1+PU1) as one element. Institutional ab-breviations are as listed in Leviton et al. (1985) with the addition of Asociaciön Ictiolögica, La Plata, Argentina (AI) and Facultad de Ciencias, Universidad de la Repü-blica, Montevideo, Repüblica Oriental del Uruguay (ZVC-P). Hisonotus candombe, spec. nov. Figs 1-3, Tab. 1 Types. Holotype: ZVC-P 5595, 29.9 mm SL, Repüblica Oriental del Uruguay, Departamento Salto, rio Uruguay basin, arroyo Palomas (31 o 04'43"S-57 o 37'26W), coli: P. Laurino et al., 17 March 2003. -Paratypes: ZSM 32062, 147
Specimen codes extracted from OCR text.
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