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| Magdalenichthys DoNascimiento, Conde-Saldaña, Albornoz-Garzón & Villa-Navarro gen. nov. Magdalenichthys lundbergi DoNascimiento, Villa-Navarro, Ortega-Lara, Albornoz-Garzón, Méndez-López & Conde-Saldaña, M. mompox DoNascimiento, Villa-Navarro, Albornoz-Garzón, Méndez-López & Conde-Saldaña, M. poira Villa-Navarro, DoNascimiento, Albornoz-Garzón, Méndez-López & Conde-Saldaña, M. yariguies DoNascimiento, Albornoz-Garzón, Méndez-López, Villa-Navarro & Conde-Saldaña in DoNascimiento, Villa-Navarro, Albornoz-Garzón, Conde-Saldaña, Silva, Méndez-López, Roxo, Ortega-Lara et Oliveira, 2025. |
Abstract
A new genus of heptapterid catfish, Magdalenichthys gen. nov., largely ignored for the past two decades is herein described. Comprehensive examination of specimens in Colombian ichthyological collections and additional samplings in the Magdalena basin were the base for an integral analysis using morphological characters, DNA barcode delimitation, and molecular phylogenetic analyses to assess monophyly and relationships of the new genus, and to delimit and diagnose four new species, Magdalenichthys lundbergi sp. nov., Magdalenichthys mompox sp. nov., Magdalenichthys poira sp. nov., and Magdalenichthys yariguies sp. nov., endemic to the Magdalena basin. The new genus is phylogenetically diagnosed. Maximum likelihood, Bayesian inference, and coalescent-based analyses with ultraconserved elements (UCEs) data, place the new genus as sister to Phenacorhamdia, within a clade also containing Cetopsorhamdia and Pariolius, consistent with the finding of two apomorphic characters shared by the new genus and Phenacorhamdia. The biogeographic pattern of the new genus (restricted to the Magdalena basin) is also discussed.
Andes, DNA barcode, freshwater fishes, iterative taxonomy, phylogenomics, South America, species delimitation, systematics, trans-Andean, ultraconserved elements
Magdalenichthys DoNascimiento, Conde-Saldaña, Albornoz-Garzón & Villa-Navarro gen. nov.
Type species: Magdalenichthys lundbergi DoNascimiento, Villa-Navarro, Ortega-Lara, Albornoz-Garzón, Méndez-López & Conde-Saldaña sp. nov.
Diagnosis: A member of the tribe Heptapterini as defined by Silva et al. (2021). Magdalenichthys is distinguished from all other heptapterids by a single autapomorphy: posterolateral corner of lateral ethmoid with pointed posterior process, extending parallel and adjacent to the lateral margin of neurocranium, contacting the lateral margin of frontal, at level of anterior region of orbitosphenoid (vs. posterolateral region of lateral ethmoid devoid of any process, ending at posterior articulation with orbitosphenoid) (Fig. 1). Additionally, Magdalenichthys can be recognized from all members of Heptapterini (except Phenacorhamdia Dahl, 1961) by having a prognathous mouth (vs. terminal, subterminal, or ventral). Magdalenichthys differs from Phenacorhamdia by having an upper caudal-fin lobe longer than the lower lobe (vs. lower caudal-fin lobe longer) and hemal spines of vertebrae dorsal to insertion of anal fin simple (vs. bifid). Another character useful for its recognition among Heptapterini species from the Magdalena basin (except Imparfinis timana Ortega-Lara, Milani, DoNascimiento, Villa-Navarro & Maldonado-Ocampo, 2011) is the adipose-fin shape roughly rectangular [vs. rounded in Cetopsorhamdia boquillae Eigenmann, 1922 or triangular in Cetopsorhamdia molinae Miles, 1943, Cetopsorhamdia nasus, Imparfinis nemacheir (Eigenmann & Fisher, 1916), and Imparfinis usmai Ortega-Lara, Milani, DoNascimiento, Villa-Navarro & Maldonado-Ocampo, 2011], being further and easily recognized from I. timana by its shorter maxillary barbel, never surpassing the distal edge of the pectoral fin (vs. extending at least to the pelvic-fin base), and pelvic-fin origin at vertical though dorsal-fin origin or slightly posterior (vs. inserted at or slightly posterior to middle of dorsal-fin base).
Included species: Magdalenichthys lundbergi sp. nov., Magdalenichthys mompox sp. nov., Magdalenichthys poira sp. nov., Magdalenichthys yariguies sp. nov.
Etymology: In allusion to the Magdalena River basin, remarking on the restricted geographic distribution of this heptapterid genus to the Cauca and Magdalena rivers, which together form the main hydrographic basin of the trans-Andean region of Colombia, framed by the Western, Central, and Eastern cordilleras, the most salient feature of the Colombian geomorphology. Gender masculine.
Magdalenichthys lundbergi DoNascimiento, Villa-Navarro, Ortega-Lara, Albornoz-Garzón, Méndez-López & Conde-Saldaña sp. nov.
Etymology: The species name is dedicated to John G. Lundberg, in recognition of its seminal contributions to the systematics of pimelodoid and heptapterid catfishes, and for being an inspiring milestone in the first author’s career.
Magdalenichthys mompox DoNascimiento, Villa-Navarro, Albornoz-Garzón, Méndez-López & Conde-Saldaña sp. nov.
Etymology: The species name refers to the Cacique Mompoj of the Malibú tribe that once inhabited the region today corresponding to the municipality of Santa Cruz de Mompox, within the so-called Momposina Depression. This indigenous group was exterminated by the Spanish armies of Gerónimo Lebrón and Alonso Martín, during the Cesar massacre of 1540. Used as a noun in apposition.
Magdalenichthys poira Villa-Navarro, DoNascimiento, Albornoz-Garzón, Méndez-López & Conde-Saldaña sp. nov.
Etymology: The name poira is the most important indigenous mythological figure of the Tolima department and refers to the mischievous and libertine Mohán, who is a human-like being (when it appears in the form of a child or adolescent), with a face tanned by the sun, and penetrating and rougish eyes. The poira enchants and attracts young women, who often go to wash clothes on the banks of the river. Used as a noun in apposition.
Magdalenichthys yariguies DoNascimiento, Albornoz-Garzón, Méndez-López, Villa-Navarro & Conde-Saldaña sp. nov.
Etymology: The name yariguies honours the exterminated indigenous group that inhabited the río Cascajales drainage. Used as a noun in apposition.
Carlos DoNascimiento, Francisco Antonio Villa-Navarro, Juan G Albornoz-Garzón, Cristhian C Conde-Saldaña, Gabriel S C Silva, Alejandro Méndez-López, Fábio F Roxo, Armando Ortega-Lara and Claudio Oliveira. 2025. An unexpectedly diverse New Genus of Catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River Basin, Colombia. Zoological Journal of the Linnean Society. 204(3); zlaf048. DOI: doi.org/10.1093/zoolinnean/zlaf048 [08 July 2025]
