Redescription of the Central American electric fish Gymnotus cylindricus (Ostariophysi: Gymnotiformes: Gymnotidae), with comments on character ambiguity within the ostariophysan clade


  • Ricardo Campos-da-Paz

    1. Seção de Peixes, Museu de Zoologia da Universidade de São Paulo, Avenida Nazaré 481, Ipiranga-São Paulo-SP, CEP 04263-000, Brasil
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Gymnotus cylindricus LaMonte, a poorly studied Central American electric fish primarily observed in the Rio Motagua basin (Guatemala) and north-western Honduras, is redescribed in detail. A clear diagnosis of this species is provided, with new information on overall morphology, osteology, and colour pattern. In a separate section, comments on character ambiguity within the Ostariophysi are made, which led to a reinterpretation of seven homoplastic characters proposed by Fink & Fink (1981) in their work on interrelationships among five major lineages of the superorder. Although the topology of their cladogram remains unchanged, the present view is that alternative explanations regarding evolution of those characters are possible, and the new ones here offered agree with initial hypotheses of primary homologies.