410 Accepted by L. Page: 15 Jan. 2004; published: 22 Jan. 2004 1 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2004 Magnolia Press Zootaxa 410: 1–11 (2004) www.mapress.com/zootaxa/ Apteronotus eschmeyeri, a new species of ghost knifefish from the Magdalena Basin, Colombia (Gymnotiformes: Apteronotidae) CARLOS DAVID DE SANTANA* ,1 , JAVIER A. MALDONADO-OCAMPO 2 , WILL- IAM SEVERI 3 & GEORGE NILSON MENDES 4 1 Mestrado em Biologia Animal, Departamento de Biologia Animal, Universidade Federal de Pernambuco, Av. Prof. Nelson Chaves 1235, Cidade Universitária, CEP 50.670-420 Recife - PE, Brazil. 2 Instituto Alexander von Humboldt, Inventories program, Claustro de San Agustín, Villa de Leyva, Boyacá, Colombia. 3 Laboratório de Ictiologia, Departamento de Pesca, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, Dois Irmãos, Recife, PE, Brazil. 4 Departamento de Zoologia, Universidade Federal de Pernambuco, Av. Prof. Nelson Chaves 1235, Cidade Universitária, CEP 50.670-420 Recife - PE, Brazil. * Corresponding author; Email: apteronotidae@ig.com.br Current address: Laboratório de Biologia Evolutiva de Peixes Eletrosensitivos, Instituto Nacional de Pesquisas da Amazônia, Manaus - AM, Brazil. Abstract Apteronotus eschmeyeri n. sp. is described here from the Magdalena Basin in Colombia and distin- guished from congeners by the following combination of features: blotchy coloration on body, clear band from chin to the beginning of dorsal mid-saggital electroreceptororgan, two clear bands sur- rounding the caudal peduncle in specimens up to 165 mm TL, mouth rictus passing the posterior margin of orbit. The present work demonstrates that the Trans-Andean apteronotids may be more diverse than previously supposed. Key words: Trans-Andean, biodiversity, taxonomy, classification Introduction Apteronotidae Jordan is the most species-rich gymnotiform family, with 45 species cur- rently recognized as valid (Mago-Leccia, 1994; Albert, 2001; Albert, 2003; de Santana, 2003). This family is widely distributed through South America and is most diverse in the Amazon Basin (Albert and Campos-da-Paz, 1998). Seven endemic species of Apter- onotidae have been described from Trans-Andean drainages (de Santana, 2002). Meek and