New Arrangement in the Synonymy of Megalechis Reis, 1997 (Siluriformes: Callichthyidae)
The recent examination of the holotypes of Callichthys thoracatus and Callichthys longifilis led to important modifications in the nomenclature of the two species of Megalechis. Inspection of these holotypes demonstrated that they represent the species that has commonly been referred to in current literature as Megalechis personata. Because C. thoracatus is an older name than C. personatus, it has priority and is considered as the senior synonym. Callichthys pictus is the oldest name applicable to the species commonly referred to in current literature as Megalechis thoracata, and is thus the valid name. Rearranged synonymies, updated diagnoses, and illustrations are provided for both species of Megalechis.Abstract
Megalechis thoracata and Megalechis picta. (A) Holotype of Callichthys thoracatus, MNHN 4266, 137.0 mm SL, Mana, French Guiana. (B) Holotype of Callichthys longifilis, MNHN 4284, 96.3 mm SL, Cayenne, French Guiana. (C) Holotype of Callichthys pictus, ZMB 3151, 144.0 mm SL, Guyana. Photo by Peter Bartsch. (D) Megalechis thoracata, MCP 35600, 65.8 mm SL, upper Rio Tapajós, between Comodoro and Vilhena, Mato Grosso, Brazil. (E) Megalechis picta, MCP 17304, 61.7 mm SL, Laguna Tonina, La Esmeralda, Amazonas, Venezuela
Scatter plot of the ratio length of dorsal-fin spine by length of dorsal-fin base versus standard length. Dots = Megalechis thoracata, squares = Megalechis picta. 1: holotype of Callichthys thoracatus; 2: holotype of Callichthys longifilis; 3: holotype of Callichthys pictus
Contributor Notes
(RER) Laboratory of Ichthyology, Pontificia Universidade Católica do Rio Grande do Sul, Av. Ipiranga, 6681, 90619–900 Porto Alegre, Brazil; (PYLB) SCRIBE-INRA, Campus de Beaulieu, Avenue du Général Leclerc, 35042 Rennes Cedex, France; (JHAM) University of Suriname, Center for Agricultural Research in Suriname CELOS and Department of Biology, P. O. Box 9212, Paramaribo, Suriname. (RER) reis@pucrs.br Send reprint requests to RER.