Rediscovery of the holotype of Characidium sanctjohanni Dahl 1960 (Characiformes: Crenuchidae) from the Colombian Pacific slope

Rediscovery of the holotype of Characidium sanctjohanni Dahl 1960 (Characiformes: Crenuchidae) from the Colombian Pacific slope

Henry D. Agudelo-Zamora^I; Armando Ortega-Lara^I; Donald C. Taphorn B.^II

^IGrupo de Investigación en Peces Neotropicales, Fundación para la Investigación y el Desarrollo Sostenible FUNINDES, Cali, Colombia. E-mail: [e-mail]; [e-mail]

^II1822 N. Charles St., Belleville, IL, 62221 USA, E-mail: [e-mail]

ABSTRACT

We report the rediscovery of the holotype of Characidium sanctjohanni Dahl, previously considered as lost in the ICN collections. We present counts, measurements and photographs, also offering a comparison between the holotype and the original description.

Key-words: San Juan River; ICZN; South America; Fish.

RESUMEN

Presentamos el redescubrimiento de la especie Characidium sanctjohanni descrita por Dahl (1960), lote que se encontraba perdido en el ICN. Tomamos conteos, medidas y fotografías para comparar los datos del holotipo con la descripción original.

Palabras-claves: Río San Juan, ICZN, Sur América, Pez.

INTRODUCTION

Characidium sanctjohanni Dahl was described from the Río San Juan, western Colombia, based on a single specimen. Until now however, the lot containing the holotype had not been found in the ICNMHN type collection (Cala, 1981; Mojica & Castellanos, 2007, 2009; Maldonado-Ocampo, 2009), and neither had a neotype been designated for that species (Buckup, 2003), which was considered valid by Buckup (1993). In the course of a revisionary study of the species of Characidium from Colombia, the holotype of Characidium sanctjohanni, which had hitherto gone unnoticed among the non-type lots of the fish collection, was found. The discovery is reported herein, but the issue of its taxonomic status is not fully resolved. Our measurements of the specimen were taken following Buckup (1993).

RESULTS AND DISCUSION

Characidium sanctjohanni Dahl was described in Caldasia 8(39): 477-480, as the only known species of the genus from the Pacific slope of Colombia. When designating the holotype the author wrote: "One specimen of 46.5 mm. skeletal length, collected at Noanamá, Río San Juan, November 3rd, 1959. This is the only specimen as yet known". The description published by Dahl (1960) presented few details on scale counts and other features of the holotype, and its sex was not stated. The specimen found in lot ICNMHN 211, identified as Characidium sanctjohanni should be considered as the holotype described by Dahl, in conformance with Article 72, condition 72.4.1.1, and also taking into account Recommendation 73F of the International Code of Zoological Nomenclature for the following reasons: Dahl mentioned a single specimen in the original material he used to describe this species; the data on the label found in this lot coincides with the original description (Fig. 1); measurements match in general those reported by Dahl, with some minor differences (Table 1). It is important to note that Dahl (1960) did not report measurements (i.e., snout length, orbital diameter) as proportions of head length but instead gave them as percentages of Standard Length. We have recalculated these as % HL to permit better comparison but it is not the aim of this paper to present a complete redescription of this species.

Historical records indicate that the fishes collected and described by Dahl (holotypes and paratypes) in Caldasia all have low catalog numbers of just two or three digits, indicating that these were the first lots incorporated by Dahl into the fish collection of ICNMHN (Andrade-C & Lynch, 2007); as examples of this we have Brycon medemi Dahl (Holotype ICNMHN 41; Paratype ICNMHN 73), Dolichancistrus atratoensis (Dahl, 1960) (Holotype ICNMHN 51; Paratype ICNMHN 46), Brycon tovari Dahl (Holotype ICNMHN 110; Patarype ICNMHN 67), and Parastremma pulcra Dahl, (Holotype ICNMHN 204; Paratype ICNMHN 204a), all of which were collected from the Chocó biogeographic region (Cala, 1981, Mojica & Castellanos, 2007, 2009).

Figure 2 shows the current condition of the holotype of Characidium sanctjohanni Dahl 1960. Life colors were provided by Dahl (1960), who indicated that this species is similar in coloration to C. caucanum, but photographs of live specimens are not available. In the illustration made by Octavio Bernal no vertical bars are shown (see Buckup & Reis, 1997 for color description), however, a horizontal stripe is still visible from the snout across the head.

ACKNOWLEDGMENTS

The authors thank J. Iván Mojica (ICNMHN) for allowing access to the collection and Ofelia Mejía Egas for the assistance. HAZ wishes to thank Hernan Martinez Satizabal for support; Jorge Escobar, Ariel Bermudez, Frank Alvarez, Juan G. Ospina, Andres F. Montoya, Carlos A. Garcia, Gustavo A. Ballen and Yesid López for their willingness to share data of Characidium, and special thanks to Paulo Buckup for suggestions and criticism. AOL thanks the Fundación para la Investigación y el Desarrollo Sostenible FUNINDES for financial and logistic support.

Aceito em: 08/07/2014

Publicado em: 30/09/2014

• Andrade-C., G. & Lynch, J. (Eds.). 2007. Los tipos nomenclaturales depositados en la colección zoológica del Instituto de Ciencias Naturales. Bogota, Facultad de Ciencias Naturales. Universidad Nacional de Colombia. 211p. (Biblioteca José Jerónimo Triana, n. 16).
• Buckup, P.A. 1993. Review of the characidiin fishes (Teleostei: Characiformes), with descriptions of four new genera and ten new species. Icthyological Exploration of Freshwaters, 4:97-154.
• Buckup, P.A. 2003. Family Crenuchidae. In: Reis, R.E.; Kullander, S.O. & Ferraris Jr., C.J. (Eds.). 2003. Checklist of the freshwater fishes of South and Central America. Porto Alegre, EDIPUCRS. p. 87-95.
• Buckup, P.A. & Reis, R.E. 1997. Characidiin Genus Characidium (Teleostei, Characiformes) in Southern Brasil, with Description of Three New Species. Copeia, 1997(3):531-548.
• Cala, P. 1981. Catálogo de los ejemplares tipo en la colección de peces del Instituto de Ciencias Naturales, Museo de Historia Natural de la Universidad Nacional de Colombia. Lozania. Acta Zoologica Colombiana, 34:1-5.
• Dahl, G. 1960. New fresh-water fishes from Western Colombia. Caldasia, 8(39):451-484.
• Maldonado-Ocampo, J.A. (Ed.). 2009. Colecciones ictiológicas colombianas. Bogotá D.C., Instituto Alexander von Humboldt. Colombia. 194p.
• Mojica J. & Castellanos, C. 2007. Colección de ictiología. In: Andrade-C., G. & Lynch, J. (Eds.). 2007. Los tipos nomenclaturales depositados en la colección zoológica del Instituto de Ciencias Naturales. Bogota, Facultad de Ciencias Naturales. Universidad Nacional de Colombia. p. 75-88. (Biblioteca José Jerónimo Triana, n. 16).
• Mojica, J.I. & Castellanos, C. 2009. Colección de peces del Instituto de Ciencias Naturales de la Universidad Nacional de Colombia (ICN-MHN). In: Madonado-Ocampo, J.A. (Ed.). 2009. Colecciones ictiologicas Colombianas. Bogota D.C, Instituto Alexander von Humboltd. p. 15-26.

Publication Dates

• Publication in this collection
  10 Oct 2014
• Date of issue
  2014

History

• Accepted
  30 Sept 2014
• Received
  08 July 2014