A new species of Xyliphius, a rarely sampled banjo catfish (Siluriformes: Aspredinidae) from the rio Tocantins-Araguaia system

Carlos A Figueiredo,Marcelo R Britto

doi:10.1590/s1679-62252010000100013

Abstract

Xyliphius anachoretes, a new species of aspredinid catfish is described from the Tocantins-Araguaia River system. Xyliphius anachoretes is diagnosed by the presence of six developed retrorse serrae on posterior border of pectoral-fin spine, presence of papillae on the lower lip bearing minute branches, and only two dorsal procurrent rays. Comments about the informativeness of character-state variation among Xyliphius species and aspredinid related genera are furnished. Also, a brief discussion about conservation status of the new taxon is made.

Highlights

The banjo catfish genus Xyliphius was established by Eigenmann (1912) to include a single species, X. magdalenae Eigenmann, from río Magdalena basin, Girardot, Colombia
Four species were described in a short time frame: X. lepturus and X. melanopterus from western headwaters of río Bobonaza, upper Amazon basin (Orcés, 1962), X. barbatus (Alonso de Arámburu & Arámburu, 1962), and X. lombarderoi (Risso & Risso, 1964), from río Paraná, in Argentina
The six nominal species of Xyliphius are known from northern South America in the río Magdalena system (X. magdalenae), lago de Maracaibo (X. kryptos), and western headwaters of the Amazonas basin and río Orinoco (X. lepturus and X. melanopterus), and from southern South America in the río de La Plata system (X. barbatus and X. lombarderoi) (Taphorn & Lilyestrom, 1983; Galvis et al, 1997; Calviño & Castello, 2008)

Summary

Introduction

The banjo catfish genus Xyliphius was established by Eigenmann (1912) to include a single species, X. magdalenae Eigenmann, from río Magdalena basin, Girardot, Colombia. Two years later (2005), another single, small specimen (25.6 mm SL) of the genus was discovered in the rio Araguaia basin, nearly 195 air km from the first locality. Examination of both specimens confirms their conspecificity and distinctiveness from nominal Xyliphius. Despite seven years of intensive collection efforts during fish surveys of the Serra da Mesa Dam from the same region where the holotype was collected, no other specimens were found Specimens of another aspredinid species, Bunocephalus cf aleuropsis were extensively collected in the same region and during the same period. Xyliphius anachoretes is promptly distinguished by the lower number of dorsal procurrent rays (two) from X. lepturus (four or five), X. melanopterus (three), and X. magdalenae (four)

Material and Methods

Discussion

Literature Cited