Sunday, August 4, 2024

[Ichthyology • 2024] Re-description of Xyliphius barbatus (Siluriformes: Aspredinidae), with comments on Osteology and Distribution


 Xyliphius barbatus Alonso de Arámburu & Arámburu, 1962, 

in Terán, Méndez-López, Benitez, Serra, Bogan et Aguilera, 2024. 

Abstract
The banjo catfish, Xyliphius barbatus, belongs to the Aspredinidae family and typically inhabits the main channels of medium to large rivers in the La Plata River basin. The mimetic coloration with the substrate and the benthic lifestyle likely contribute to the challenge of sampling this species, resulting in its underrepresentation in museums and ichthyological collections. In fact, the original description of X. barbatus was based solely on two specimens. Consequently, little is known about its osteology, distribution, and phylogenetic relations. In this work, these information gaps are filled and the distributional range for X. barbatus is extended to northwestern Argentina.

Key Words: Banjo catfish, fossorial fishes, La Plata River basin, morphology, osteology

Lateral, dorsal and ventral views of Xyliphius barbatus. CI-FML 7944. San Francisco River, Bermejo River basin, Jujuy province. Scale bar: 10 mm.

CI-FML 7944. Xyliphius barbatus. Live specimen, 92.4 mm SL. San Francisco River, Bermejo River basin, Jujuy. Scale bar: 10 mm.

 Xyliphius barbatus Alonso de Arámburu & Arámburu, 1962

Diagnosis: Xyliphius barbatus is distinguishable from the remaining species of genus by the following combination of characters: (1) seven to 11 retrorse dentations on posterior margin of pectoral-fin spine (vs. six in X. anachoretes and four or five in X. magdalenae); (2) 24 to 30 dendriform papillae on inferior lip (vs. 20–22 in X. magdalenae, 30 in X. sofiae, and 22 to 27 triangular papillae, with only the lateral ones branched in X. kryptos); (3) I,3 or I,4 dorsal-fin rays (vs. I,5 in X. lepturus and X. melanopterus); (4) absence of dorsal pale band from snout tip to caudal-fin origin (vs. presence in X. anachoretes, X. magdalenae and X. melanopterus); (5) absence of a latero-dorsal band following the second row of tubercles on anterior part of body (vs. present in X. magdalenae and X. melanopterus); (6) eyes present and reduced (vs. absent in X. sofiae); (7) five to eight anal-fin rays (vs. nine in X. lepturus).


 Guillermo E. Terán, Alejandro Méndez-López, Mauricio F. Benitez, Wilson S. Serra, Sergio Bogan and Gastón Aguilera. 2024. Re-description of Xyliphius barbatus (Siluriformes, Aspredinidae), with comments on Osteology and Distribution. Zoosystematics and Evolution. 100(3): 1085-1097. DOI:  doi.org/10.3897/zse.100.121396