Magdalenichthys DoNascimiento, Conde-Saldaña, Albornoz-Garzón & Villa-Navarro, 2025

Magdalenichthys DoNascimiento, Conde-Saldaña, Albornoz-Garzón & Villa-Navarro gen. nov.

ZooBank registration: urn:lsid:zoobank.org:act:.

Type species: Magdalenichthys lundbergi DoNascimiento, Villa-Navarro, Ortega-Lara, Albornoz-Garzón, Méndez-López & Conde-Saldaña sp. nov.

Diagnosis: A memberofthetribeHeptapterini as defined bySilva 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 View Figure 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.