taxonID	type	description	language	source
EB5CB23FE509FF872C66FE6DFE21F9D7.taxon	description	ZooBank registration: urn: lsid: zoobank. org: act: 3 D 9186 FC- 1 D 47 - 4 E 6 F- 8676 - 2 CF 3172216 B 3.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE509FF872C66FE6DFE21F9D7.taxon	type_taxon	Type species: Magdalenichthys lundbergi DoNascimiento, Villa-Navarro, Ortega-Lara, Albornoz-Garzón, Méndez-López & Conde-Saldaña sp. nov.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE509FF872C66FE6DFE21F9D7.taxon	diagnosis	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). 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).	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE509FF872C66FE6DFE21F9D7.taxon	etymology	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.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE50EFF8A2FBFF999FB71FC81.taxon	description	(Figs 2 – 3; Table 1) ZooBank registration: urn: lsid: zoobank. org: act: E 4 A 72405 - C 852 - 4 FDF- 83 EF-F 1 C 2 B 864 AA 72.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE50EFF8A2FBFF999FB71FC81.taxon	materials_examined	Holotype: CZUT-IC 25785 (80.9 mm SL); Colombia, Quindío, Armenia, río Verde, tributary of río Quindío, río La Vieja drainage, Cauca River sub-basin, 04 ° 23 ’ 43 ” N 75 ° 45 ’ 60 ” W, 1105 m a. s. l.; J. L. Lozano & G. Murcia, 26 Oct 2017. Paratypes: CIUA 3841 (1, 62.3 mm SL); Caldas, Neira, río Tareas, tributary of río Tapias, 05 ° 13 ’ 22.1 ” N 75 ° 38 ’ 14.2 ” W, 859 m a. s. l.; J. G. Ospina-Pabón, 8 Mar 2015. CIUA 3843 (2, 46.0 – 63.5 mm SL); Caldas, Neira, río Tapias, close to the bridge, 05 ° 13 ’ 23.8 ” N 75 ° 38 ’ 16.4 ” W, 853 m a. s. l.; J. G. Ospina Pabón, 3 Mar 2015. CIUA 3856 (1, 69.3 mm SL); Caldas, Río Sucio, río Sucio, tributary of río Supía, 05 ° 22 ’ 44.6 ” N 75 ° 36 ’ 57.9 ” W, 773 m a. s. l.; J. G. Ospina Pabón, 10 Mar 2015. CIUA 3929 (1, 50.5 mm SL); Caldas, Viterbo, vereda La Merced, río Risaralda, 05 ° 05 ’ 19.7 ” N 75 ° 51 ’ 15 ” W, 983 m a. s. l.; J. G. Ospina Pabón, 5 Dec 2014. CIUA 3961 (2, 59.4 – 75.2 mm SL); Caldas, Belalcázar, quebrada El Zancudo, tributary of río Risaralda, 04 ° 57 ’ 51.3 ” N 75 ° 51 ’ 30.2 ” W, 941 m a. s. l.; J. G. Ospina Pabón; 7 Dec 2014. CIUA 3982 (1, 51.5 mm SL); Caldas, Viterbo, río Guarne, tributary of río Risaralda, 05 ° 05 ’ 29 ” N 75 ° 52 ’ 04 ” W, 986 m a. s. l.; J. G. Ospina-Pabón, 6 Dec 2014. CIUA 5399 (1, 27.9 mm SL); Valle del Cauca, Alcalá, quebrada Los Ángeles, 4.71324 ° – 75.8529 °; J. Herrera, 10 Feb 2019. CIUA 5400 (1, 73.5 mm SL); Caldas, Belalcázar, quebrada El Zancudo, 4.96425 ° – 75.85837 °; D. Valencia, 11 Feb 2019. CIUA 7985 (10, 39.2 – 72.0 mm SL); Valle del Cauca, Bugalagrande, río Bugalagrande, 04 ° 10 ’ 46.9 ” N 76 ° 08 ’ 54.2 ” W; J. Ospina-Pabón, V. M. Medina Ríos, D. Restrepo Santamaría, 1 Sep 2022. CZUT-IC 12230 (3, 29.1 – 68.7 mm SL); Quindío, Armenia, río Quindío, tributary of río La Vieja, 04 ° 23 ’ 45 ” N 75 ° 45 ’ 47 ” W; L. Arrieta & I. Pareja, 1 Jun 2014. CZUT-IC 12368 (8, 35.9 – 81.5 mm SL); Quindío, Calarcá, río Quindío, tributary of río La Vieja, 04 ° 31 ’ 47 ” N 75 ° 38 ’ 25 ” W; A. Ortega-Lara, 1 Sep 2004. CZUT-IC 12397 (6, 24.2 – 75.3 mm SL); Quindío, Pijao, río Barragán, tributary of río Quindío, río La Vieja drainage, Cauca River sub-basin, 04 ° 20 ’ 02 ” N 75 ° 42 ’ 09 ” W, A. Ortega-Lara, 1 Sep 2004. CZUT-IC 12408 (4, 21.6 – 59.2 mm SL); Quindío, río Barragán, tributary of río Quindío, río La Vieja drainage, Cauca River sub-basin, 04 ° 20 ’ 02 ” N 75 ° 42 ’ 09 ” W; A. Ortega-Lara, 7 Dec 2004. CZUT-IC 18353 (1, 70.5 mm SL); Valle del Cauca, Yotoco, río Mediacanoa, tributary of Cauca River, 03 ° 54 ’ 17 ” N 76 ° 23 ’ 56 ” W, 993 m a. s. l.; A. Ortega-Lara & G. Sánchez-Garcés, 3 Aug 2017. CZUT-IC 18829 (4, 20.7 – 44.8 mm SL); Valle del Cauca, Zarzal, río La Paila, tributary of Cauca River, 04 ° 18 ’ 36 ” N 76 ° 02 ’ 57 ” W, 952 m a. s. l.; J. G. Albornoz-Garzón, J. E. García-Melo & B. Melo, 20 Aug 2017. CZUT-IC 19240 (2, 41.1 – 46.2 mm SL); Quindío, río Verde, tributary of río Quindío, río La Vieja drainage, Cauca River sub-basin, 04 ° 23 ’ 43 ” N 75 ° 45 ’ 60 ” W, 1105 m a. s. l.; J. L. Lozano & G. Murcia, 26 Oct 2017. CZUT-IC 19332 (2, 30.7 – 61.4 mm SL); Quindío, río Verde, tributary of río Quindío, río La Vieja drainage, Cauca River sub-basin, 04 ° 23 ’ 43 ” N 75 ° 45 ’ 60 ” W, 1105 m a. s. l.; J. L. Lozano & G. Murcia, 26 Dec 2017. CZUT-IC 19392 (1, 58.8 mm SL, 1 c & s, 49.8 mm SL); Quindío, Armenia, río Verde, tributary of río Quindío, río La Vieja drainage, Cauca River sub-basin, 04 ° 23 ’ 43 ” N 75 ° 45 ’ 59 ” W, 1105 m a. s. l.; J. L. Lozano & G. Murcia, 28 Jan 2018. CZUT-IC 19240 (2, 41.1 – 53.2 mm SL); collected with holotype. CZUT-IC 20459 (4, 46.7 – 62.3 mm SL), Caldas, Anserma, río Risaralda, 05 ° 10 ’ 30 ” N 75 ° 49 ’ 04 ” W, 1040 m a. s. l.; J. L. Lozano, 12 Dec 2018. IMCN 3506 (20, 39.2 – 85.2 mm SL, 2 c & s, 78.8 – 87.7 mm SL); Cauca, Santander de Quilichao, río Quinamayó, tributary of Cauca River sub-basin, 03 ° 06 ’ 29.6 ” N 76 ° 32 ’ 13.4 ” W, 975 m a. s. l.; A. Ortega-Lara, 21 Apr 2004.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE50EFF8A2FBFF999FB71FC81.taxon	diagnosis	Diagnosis: Magdalenichthys lundbergi differs from all its congeners by number of vertebrae (36 – 37 vs. 32 – 33 in M. mompox, 38 – 39 in M. poira, 40 in M. yariguies). Magdalenichthys lundbergi is distinguished from M. poira and M. yariguies by having five or more dentary tooth rows (vs. four). Magdalenichthys lundbergi is distinguished from M. mompox and M. yariguies by having the adipose-fin origin opposite to the anal-fin origin (vs. posterior). Magdalenichthys lundbergi further differs from M. mompox by having a parabolic contour of the head in dorsal view, with lateral profiles convex (vs. rectangular, with lateral profiles straight); fewer gill rakers on first arch (3 – 5 vs. 7 – 8); first dorsal-fin pterygiophore inserted posterior to neural spine of vertebrae 10 – 11 (vs. vertebra 9); first anal-fin pterygiophore inserted posterior to hemal spine of vertebrae 23 – 24 (vs. vertebra 21); upper caudal-fin lobe distinctively longer than the lower lobe (vs. both lobes subequal); shorter caudal-fin lower lobe (16 – 20.5 % of SL vs. 21.9 – 24.9 %); fewer caudal-fin branched rays (13 vs. 15); shorter prepelvic length (35.1 – 42.6 % of SL vs. 42 – 47.9 %); longer adipose-fin base (22.8 – 29.8 % of SL vs. 17.5 – 20.9 %); wider mouth (36.1 – 43.7 % of HL vs. 28.7 – 36.3 %); shorter maxillary barbel (17.5 – 23 % of HL vs. 22.8 – 32.1 %); and shorter inner mental barbel (8.6 – 12 % of HL vs. 12.5 – 15.8 %). Magdalenichthys lundbergi further differs from M. poira by having modally fewer branched rays in the upper lobe of the caudal fin (six vs. seven); translucent or pale nuchal band inconspicuous and narrow in small specimens, faded or absent in large specimens (vs. conspicuous and wide in specimens of all sizes); pale spot at dorsal-fin origin narrow in specimens of up to 72.1 mm SL, absent in larger specimens (vs. wide and triangular, always present in specimens of all sizes); and adipose fin dusky (vs. hyaline). Magdalenichthys lundbergi is further distinguished from M. yariguies by having fewer anal-fin principal (segmented) rays (9 – 10 vs. 11 – 12); insertion of anal fin extending posteriorly to hemal spine of vertebrae 29 – 30 (vs. vertebrae 33 – 34), which is externally reflected in a longer caudal peduncle in M. lundbergi (20.1 – 24.2 % of SL vs. 16.3 – 19.3 %); shorter anal-fin base (11.7 – 14.4 % of SL vs. 15.6 – 18.1 %); and shorter maxillary barbel (17.5 – 23 % of SL vs. 24.2 – 30.9 %).	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE50EFF8A2FBFF999FB71FC81.taxon	description	Description: Morphometric data in Table 1. Refer to Figure 2 for general appearance. Small heptapterine catfish (largest specimen 80.9 mm SL), with elongated body, elliptical in cross-section at dorsal-fin origin (longest axis vertical), progressively more compressed to caudal region. Dorsal profile slightly convex from snout tip to occipital region, straight immediately posterior to this point to adipose-fin origin, sloping ventrally along adipose-fin base to origin of procurrent caudal-fin rays, and slightly ascending along dorsal membrane supported by procurrent caudal-fin rays. Ventral profile straight to pelvic-fin insertion, slightly concave to anal-fin origin, dorsally sloping along anal-fin base, straight along caudal peduncle to origin of procurrent caudal-fin rays and slightly descending along ventral membrane supported by procurrent caudal-fin rays. Head depressed, parabolic in dorsal view, dorsally covered by thin skin. Cheek laterally bulged with muscular mass of adductor mandibulae, but muscle not reaching dorsally onto skull roof. Snout short and rounded. Mouth slightly prognathous. Premaxillary teeth arranged in a rhomboidal patch of 5 * – 9 medial and 8 * – 11 lateral irregular rows of minute conical teeth. Lower jaw slightly longer than upper jaw. Dentary teeth in 5 – 8 (7) irregular rows of minute conical teeth, similar to those on premaxilla. Maxillary barbel reaching base of unbranched pectoral-fin ray. Conspicuous groove accommodating anterior part of maxillary barbel along sides of head, extending posteriorly to vertical through posterior margin of posterior nares. Bases of outer and inner mental barbels in a straight line. Mental barbels not reaching base of pectoral fin. Outer mental barbel surpassing branchiostegal membrane. Inner mental barbel reaching edge of branchiostegal membrane. Small subcutaneous eye, dorsal in position and twice longer horizontally than vertical diameter. Anterior naris tubular. Posterior naris closer to anterior margin of eye than to anterior naris, anteriorly bordered by a low fleshy margin. Anterior and posterior internarial widths equal. Nares disposed in a squared arrangement. Branchiostegal membrane free, supported by eight (2) * or nine (1) rays and joined to isthmus only at anteriormost point. Gill rakers on first arch 3 – 5 (one c & s specimen asymmetrically with one and two gill rakers), located along anterior margin of ceratobranchial. Lateral line canal complete, reaching caudal skeleton. Supraorbital pore s 1 medially adjacent to anterior naris; s 2 + i 2 pore slightly closer to anterior naris (Fig. 3), at distal end of posteriorly directed membranous tubule, originating from commissure connecting supraorbital and infraorbital canals; s 3 pore not visible externally, inside posterior naris, adjacent to its posterior margin, at notch of cutaneous membrane. Contralateral supraorbital canals connected medially by epiphyseal membranous branch, dorsal to posterior portion of anterior fontanel, without superficial pore; s 8 pore (parietal branch) arising from a posteriorly directed membranous canal, externally located posterior to eye, at level of medial margin of eye; s 4 and s 7 branches and pores absent. Infraorbital pore i 1 laterally adjacent to anterior naris, between naris and maxillary barbel base; i 3 pore posterior to maxillary barbel base; i 4 pore slightly anterior to vertical through anterior margin of eye; i 5 pore ventral to posterior region of eye; i 6 pore posterior to eye, aligned with ventral margin of eye. Pterotic branch (po 2) at posterolateral corner of pterotic. Dentary with seven pores of preoperculo-mandibular canal. Submental pores (pm 1) paired. Sixth and seventh mandibular pores approximately at same vertical level, and seventh pore just anterior to lateral articulation between dentary and anguloarticular bones. Subpreopercular ossicle with one pore (pm 8). Preopercle with two pores, anterior pore (pm 9) originating from membranous tubule lateral to interopercle and posterior pore (pm 10) from membranous tubule passing lateral to ventral portion of opercle. Last preopercular pore (po 1 + pm 11) at end of membranous tubule, dorsal to dorsoposterior portion of opercle. Axillary branch (ll 1) ventral, running posterior to supracleithrum. Precaudal vertebrae 9 (1) – 10 (2), thoracic vertebrae 7 (1), 8 (1) or 9 (1), and caudal vertebrae 27, totalling 36 – 37 vertebrae. Ribs seven (1) or eight (2). Pectoral fin with i, 7 (13) * – 8 (7) rays. First pectoral-fin ray (unbranched) soft and shorter than first branched ray. Second branched ray longest. Distal margin of pectoral fin convex. Pelvic fin with i, 5 rays. First pelvic-fin ray (unbranched) thick and shortest, second and third branched rays longest. Pelvic-fin origin opposite to dorsal-fin origin, at vertical through vertebra 13 (2). Dorsal fin lacking spinelet, with one unbranched and five (1), six * (29) or seven (3) branched rays (one specimen out of 18 from with five branched rays), supported by seven pterygiophores. Dorsal-fin margin convex, its unbranched ray slightly shorter than first branched ray; first three branched rays subequal. First dorsal-fin pterygiophore inserted posterior to neural spine of vertebrae 10 (1) or 11 (2) and last pterygiophore anterior to neural spine of vertebrae 16 (1) or 17 (2). Adipose fin long, almost rectangular with attenuated ends and posterior lobe free. Adipose-fin origin at vertical through anal-fin origin. Anal fin with 2 (1) – 3 (2) procurrent (unsegmented) rays, 2 (8) – 3 (10) * unbranched rays, and six * (8), seven (8), or eight (2) branched rays for a total of nine (16) or 10 (4) principal rays. Posteriormost ray (branched) individually associated to last pterygiophore. Anal-fin distal margin rounded. Anal fin supported by 10 (1) – 11 (2) pterygiophores. First anal-fin pterygiophore posterior to hemal spine of vertebrae 23 (2) – 24 (1) and last pterygiophore anterior to hemal spine of vertebrae 29 (1) – 30 (2). Caudal fin deeply forked with i, 7 + 7, i principal rays (two c & s specimens of 35.9 and 68.7 mm SL with either six branched rays in lower or in upper lobe, respectively). Upper lobe of caudal fin distinctly longer than lower lobe, upper lobe generally pointed and lower lobe generally rounded. Procurrent caudal-fin rays 13 (2) or 15 (1) dorsal and 13 (1), 14 (1) or 16 (1) ventral, located posterior to vertebra PU 6. Posteriormost two dorsal and two (1) or three (2) ventral procurrent caudal-fin rays segmented. Caudal skeleton PH + 1 + 2,3 + 4 + 5. Long epural present. Pigmentation in alcohol: Overall ground coloration dark brown. Dorsal surface of head dark. Pale or translucent (superficial muscles of dorsum visible through it) band inconspicuous and narrow, between dorsal corners of branchial openings in small specimens, fading or disappearing in specimens larger than 70 mm SL. Dorsal surface posterior to nuchal band dark. Transverse elliptical or ovoid pale spot at dorsal-fin origin in specimens of 72.1 mm SL or smaller; spot absent in larger specimens. Base of dorsal and adipose fins with darker region along sides. Ventral surface of head and body pale, with sparse chromatophores posterior to ventral fins. Cheeks slightly lighter than remaining dorsal surface of head, with translucent horizontal band (cheek muscles visible through it) in small specimens. Dark chromatophores aligned along lateral line and myosepta. Maxillary barbel darkly pigmented, darker dorsally. Lateral surface of mental barbels with dark chromatophores, denser on outer barbel. Fin rays and adipose fin dusky, with numerous chromatophores. Interradial membrane of rayed fins hyaline.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE50EFF8A2FBFF999FB71FC81.taxon	distribution	Distribution: Magdalenichthys lundbergi is found in the main tributaries of the upper basin of the Cauca River (Quinamayó, Mediacanoa, La Vieja, and Risaralda rivers) (Fig. 4).	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE50EFF8A2FBFF999FB71FC81.taxon	biology_ecology	Habitat and ecological notes: Magdalenichthys lundbergi is found in sloped sectors of small to middle width (3 – 25 m) rivers, with turbulent flow and gravel bottom with rocks and boulders, along an elevational gradient from 895 to 1669 m a. s. l. The species can be found syntopically with Characidium chancoense Agudelo-Zamora, Ortega-Lara & Taphorn, 2020, Saccodon dariensis (Meek & Hildebrand, 1913), Astyanax sp., Creagrutus brevipinnis Eigenmann, 1913, Hemibrycon caucanus (Eigenmann, 1913), Hemibrycon dentatus (Eigenmann, 1913), Brycon henni Eigenmann, 1913, Chaetostoma leucomelas Eigenmann, 1918, and Cetopsorhamdia nasus. Stomachs of two dissected specimens contained remains of larvae of aquatic insects including: Trichoptera (Leptoceridae and Hidroptilidae), Plecoptera (Perlidae), and Diptera (Chironomidae), and of terrestrial groups such as Hymenoptera (Formicidae) and Orthoptera. Gonads of three dissected specimens corresponded to two ovate females with 299 (59.6 mm SL) and 358 ovocites (54.4 mm SL), and a mature male (36 mm SL). The species was informally categorized as Vulnerable in Ortega-Lara et al. (2022).	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE50EFF8A2FBFF999FB71FC81.taxon	etymology	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.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE503FF8E2C0DFC48FEA1F945.taxon	description	(Figs 5 – 6; Table 1) ZooBank registration: urn: lsid: zoobank. org: act: D 309881 B-DE 1 C- 45 F 6 - BAB 8 - 2 C 6 D 334 BA 90 A.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE503FF8E2C0DFC48FEA1F945.taxon	materials_examined	Holotype: CZUT-IC 25911 (38.0 mm SL); Colombia, Antioquia, Cáceres, Cauca River; 07 ° 41 ’ 12 ” N 75 ° 16 ’ 30 ” W, 100 m a. s. l.; D. Montoya-Ospina & D. Bedoya, 8 Feb 2019. Paratypes: Colombia: CIUA 8149 (1, 37.7 mm SL); Tolima, Ortega, río Tetuan, 03 ° 51 ’ 10.3 ” N 75 ° 16 ’ 24.2 ” W; J. G. Ospina Pabón, D. Restrepo Santamaría, J. L. Londoño López, 6 Mar 2023. CZUT-IC 15098 (10, 24.7 – 34.2 mm SL, 1 c & s, 30.9 mm SL); Cesar, El Copey, río Ariguaní, tributary of río Cesar; 10 ° 16 ’ 05 ” N 73 ° 59 ’ 14 ” W, 163 m a. s. l.; J. G. Albornoz-Garzón & G. Beltrán, 22 Oct 2015. CZUT-IC 20495 (1, 33.2 mm SL, 1 c & s, 33.4 mm SL); collected with holotype. IAvH-P 21928 (3, 21.1 – 31.5 mm SL); Colombia, Antioquia, Cáceres, Cauca River at Puerto Bélgica, 07 ° 41 ’ 25.6 ” N 75 ° 16 ’ 22.34 ” W; D. Montoya-Ospina, 4 Feb 2019.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE503FF8E2C0DFC48FEA1F945.taxon	diagnosis	Diagnosis: Magdalenichthys mompox differs from all its congeners by having a rectangular contour of the head in dorsal view, with lateral profiles straight (vs. parabolic, with lateral profiles convex); more numerous gill rakers on first arch (7 – 8 vs. 3 – 5 in M. lundbergi, 5 – 6 in M. poira, 3 – 4 in M. yariguies); fewer vertebrae (32 – 33 vs. 36 – 37 in M. lundbergi, 38 – 39 in M. poira, 40 in M. yariguies); first dorsal-fin pterygiophore inserted posterior to neural spine of vertebra 9 (vs. vertebrae 10 – 12); first anal-fin pterygiophore inserted posterior to hemal spine of vertebra 21 (vs. vertebrae 23 – 25); caudal-fin lobes subequal (vs. upper-caudal fin lobe distinctively longer than lower lobe); and more numerous caudal-fin branched rays (15 vs. 14 or fewer). Magdalenichthys mompox can be additionally distinguished from M. lundbergi and M. poira by having the adipose-fin origin posterior to the anal-fin origin (vs. origin of both fins at same vertical); narrower mouth (28.7 – 36.3 % of HL vs. 36.1 – 43.7 % in M. lundbergi, 41.3 – 53.5 % in M. poira); longer maxillary barbel (22.8 – 32.1 % of HL vs. 17.5 – 23 % in M. lundbergi, 17.5 – 23 % in M. poira); and longer inner mental barbel (12.5 – 15.8 % of HL vs. 8.6 – 12 % in M. lundbergi, 8.4 – 12.9 % in M. poira). Magdalenichthys mompox can be recognized from M. lundbergi and M. yariguies by having a longer prepelvic length (42 – 47.9 % of SL vs. 35.1 – 42.6 % in M. lundbergi, 35.4 – 41.5 % in M. yariguies); shorter adipose-fin base (17.5 – 20.9 % of SL vs. 22.9 – 29.8 % in M. lundbergi, 26.2 – 28.9 % in M. yariguies); and longer caudal-fin lower lobe (21.9 – 24.9 % of SL vs. 16 – 20.5 % in M. lundbergi, 16.3 – 19.4 % in M. yariguies). Magdalenichthys mompox can be recognized from M. poira and M. yariguies by having a longer head (22.9 – 25.1 % of SL vs. 18.4 – 22.1 % in M. poira, 16.7 – 20.4 % in M. yariguies). Magdalenichthys mompox further differs from M. poira by having more ribs (eight vs. six to seven) and fewer number of ventral procurrent caudal-fin rays (12 – 14 vs. 15 – 16). Magdalenichthys mompox further differs from M. yariguies by having fewer principal anal-fin rays (9 – 10 vs. 11 – 12); greater cleithral width (15.3 – 19.1 % of SL vs. 12.8 – 15.2 %); and shorter anal-fin base (9.9 – 13.5 % of SL vs. 15.6 – 18.1 %).	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE503FF8E2C0DFC48FEA1F945.taxon	description	Description: Morphometric data in Table 1. Refer to Figure 5 for general appearance. Small heptapterine catfish (largest specimen 38 mm SL), with elongated body, elliptical in cross-section at dorsal-fin origin (longest axis vertical), progressively more compressed to caudal region. Dorsal profile straight from snout tip to occipital region, straight and slightly ascending immediately posterior to this point to dorsal-fin origin, straight along dorsal-fin base to adipose-fin origin, sloping ventrally along adipose-fin base and slightly ascending along dorsal membrane supported by procurrent caudal-fin rays. Ventral profile of head slightly convex, then straight to anal-fin origin, dorsally sloping along anal-fin base to origin of procurrent caudal-fin rays and slightly descending along membrane supported by procurrent caudal-fin rays. Head depressed, roughly rectangular in dorsal view, dorsally covered by thin skin. Cheek filled with muscular mass of adductor mandibulae, but muscle not reaching dorsally onto skull roof. Snout short and rounded. Mouth slightly prognathous. Premaxillary teeth arranged in a rhomboidal patch of 4 – 5 * medial and 8 * – 9 lateral irregular rows of minute conical teeth. Lower jaw slightly longer than upper jaw. Dentary teeth in 4 * – 5 irregular rows of minute conical teeth, similar to those on premaxilla. Maxillary barbel reaching base of innermost pectoral-fin ray. Conspicuous groove accommodating anterior part of maxillary barbel along sides of head and delimiting dorsal and lateral regions of head. Bases of outer and inner mental barbels in a straight line. Outer mental barbel reaching pectoral-fin origin. Inner mental barbel reaching branchial opening. Small subcutaneous eye, dorsal in position and almost circular. Anterior naris tubular. Posterior naris closer to anterior margin of eye than to anterior naris, anteriorly bordered by a low fleshy margin. Anterior and posterior internarial widths equal. Nares disposed in a squared arrangement. Branchiostegal membrane free, supported by 7 or 8 rays and joined to isthmus only at anteriormost point. Gill rakers of first arch 7 – 8, located along anterior margin of ceratobranchial. Lateral line canal complete, reaching caudal skeleton. Supraorbital pore s 1 medially adjacent to anterior naris; s 2 + i 2 pore slightly closer to anterior naris (Fig. 6), at distal end of posteriorly directed membranous tubule, originating from commissure connecting supraorbital and infraorbital canals, closer to supraorbital canal; s 3 pore not visible externally, inside posterior naris, adjacent to its posterior margin, at notch of cutaneous membrane. Contralateral supraorbital canals connected medially by epiphyseal membranous branch, dorsal to middle of anterior fontanel, without superficial pore; s 8 pore (parietal branch) arising from a posteriorly directed membranous canal, externally located posterior to eye, at level of medial margin of eye; s 4 and s 7 branches and pores absent. Infraorbital pore i 1 laterally adjacent to anterior naris, between naris and maxillary barbel base; i 3 pore posterior to maxillary barbel base; i 4 pore approximately at vertical through posterior margin of posterior naris; i 5 pore at vertical through posterior margin of eye; i 6 pore posterior to eye, aligned with ventral margin of eye. Pterotic branch (po 2) at posterolateral corner of pterotic. Dentary with seven pores of preoperculo-mandibular canal. Submental pores (pm 1) paired. Sixth and seventh mandibular pores approximately at same vertical level. Subpreopercular ossicle with one pore (pm 8). Preopercle with two pores, anterior pore (pm 9) originating from membranous tubule lateral to interopercle and posterior pore (pm 10) from membranous tubule passing lateral to ventral portion of opercle. Last preopercular pore (po 1 + pm 11) at end of membranous tubule, dorsal to dorsoposterior portion of opercle. Axillary branch (ll 1) ventral, running posterior to supracleithrum. Precaudal vertebrae 9 (1) – 10 (1), thoracic vertebrae 7 (1) or 8 (1), and caudal vertebrae 23, totalling 32 – 33 vertebrae. Ribs eight (last rib shortest). Pectoral fin with i, 7 * (8) – 8 (1) rays. First pectoral-fin ray (unbranched) soft and shorter than first branched ray. First branched ray longest. Distal margin of pectoral fin convex. Pelvic fin with i, 5 rays. First pelvic-fin ray (unbranched) thick and shortest, second and third branched rays longest. Pelvic-fin origin at level of first branched ray of dorsal fin, at vertical through vertebrae 13 or 14. Dorsal fin lacking spinelet, with one unbranched and six branched rays (one c & s specimen with five branched rays), supported by seven pterygiophores. Dorsal-fin margin convex, its unbranched ray as long as first branched ray; first three branched rays subequal. First dorsal-fin pterygiophore inserted posterior to neural spine of vertebra 9 and last pterygiophore anterior to neural spine of vertebra 15. Adipose fin long, almost rectangular with attenuated ends and posterior lobe free. Adipose-fin origin at vertical through second unbranched ray of anal fin. Anal fin with 2 (1) – 3 (1) procurrent (unsegmented) rays, and 2 (4) – 3 * (5) unbranched and six * (3) or seven (5) branched rays for a total of nine (5) or ten (3) principal rays. Posteriormost one or two rays (branched) associated with last pterygiophore. Anal-fin distal margin rounded. Anal fin supported by nine pterygiophores. First anal-fin pterygiophore posterior to hemal spine of vertebra 21 and last pterygiophore anterior to hemal spine of vertebra 27. Caudal fin deeply forked with i, 7 + 8, i principal rays. Caudal-fin lobes subequal, with lower lobe slightly longer than upper lobe, both lobes pointed. Procurrent caudal-fin rays 13 (1) or 14 (1) dorsal and 12 (1) or 14 (1) ventral, located posterior to vertebra PU 5 (dorsal rays) and to PU 5 or PU 6 (ventral rays). Posteriormost two procurrent caudal-fin rays segmented. Caudal skeleton PH + 1 + 2,3 + 4 + 5. Long epural present. Pigmentation in alcohol: Overall ground coloration light brown. Minute and numerous melanophores clustered at humeral region. Dorsal surface of head and predorsal area darker than remaining of body surface. Dark streak extending dorsally on surface of snout, between base of maxillary barbel and anterior margin of eye. Conspicuous and narrow pale band posterior to head, between dorsal corners of branchial openings. Cheeks and maxilar groove lighter than remaining surface of head, peppered with sparse chromatophores. Basal portion of maxillary barbel darkly pigmented on dorsal surface. Pale transversely oval spot at dorsal-fin origin. Base of dorsal fin and adipose fin with a dark band along sides. Ventral surface of head and body pale. Adipose fin with sparse chromatophores. Rays of fins with chromatophores. Interradial membrane of fins hyaline.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE503FF8E2C0DFC48FEA1F945.taxon	distribution	Distribution: This species has a patchy distribution in three disjunct areas of the Magdalena basin, the lower course of the main channel of the Cauca River, the río Ariguaní, a tributary of the lower basin of the río Cesar, and in the río Tetuan, a tributary of the río Saldaña that drains directly in the upper basin of the Magdalena River (Fig. 4). It is expected that this distribution pattern simply reflects an artifact of sampling.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE503FF8E2C0DFC48FEA1F945.taxon	etymology	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.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE507FF932FA8F90DFC44F945.taxon	description	(Figs 7 – 8; Table 1) ZooBank registration: urn: lsid: zoobank. org: act: 8 FDB 875 FDB 8 E- 42 AD-A 6 FF- 757 D 086 E 0121.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE507FF932FA8F90DFC44F945.taxon	materials_examined	Holotype: CZUT-IC 25786 (45.2 mm SL), Colombia, Tolima, Chaparral, río Guanábanos, tributary of río Saldaña, 03 ° 31 ’ 08 ” N 75 ° 31 ’ 50 ” W; L. J. García-Melo, Y. Lozano & E. O. López-Delgado, 7 Mar 2009. Paratypes: Tolima: CZUT-IC 807 (17, 22.2 – 56 mm SL, 1 c & s, 45.2 mm SL); Coello, quebrada Gualanday, tributary of río Coello, 04 ° 18 ’ 17 ” N 75 ° 00 ’ 51 ” W; F. A. Villa-Navarro, A. Ortega-Lara, L. J. García-Melo, N. G. Briñez-Vásquez & P. T. Zúñiga-Upegui, 9 May 2003. CZUT-IC 1619 (5, 38.7 – 53.8 mm SL); Cunday, río Cunday, tributary of río Prado, 03 ° 54 ’ 22 ” N 74 ° 44 ’ 40 ” W; F. A. Villa-Navarro, L. J. García-Melo, D. Castro Roa & M. E. Herrada-Yara, 18 Aug 2004. CZUT-IC 1621 (4, 40.7 – 49.2 mm SL); Cunday, río Cunday, tributary of río Prado, 04 ° 01 ’ 58 ” N 74 ° 34 ’ 57 ” W; F. A. Villa-Navarro, L. J. García-Melo, D. Castro Roa & M. E. Herrada-Yara, 23 Aug 2004. CZUT-IC 1624 (8, 24.1 – 55.9 mm SL); same locality as CZUT-IC 1619; F. A. Villa-Navarro, L. J. García-Melo, D. Castro Roa & M. E. Herrada-Yara, 15 Nov 2004. CZUT-IC 3176 (9, 24.2 – 62.9 mm SL); collected with holotype. CZUT-IC 5679 (17, 28.3 – 46.2 mm SL, 1 c & s, 44.8 mm SL); Natagaima, río Anchique, 03 ° 35 ’ 19.2 ” N 75 ° 07 ’ 35.7 ” W, 361 m a. s. l.; M. C. Moreno-Palacios, C. Yara-Ortiz, F. A. Villa-Navarro & E. López, 21 Nov 2010. CZUT-IC 8624 (13, 30.8 – 55.1 mm SL, 2 c & s, 44.6 – 45.5 mm SL); same locality as CZUT-IC 807; F. A. Villa-Navarro, 23 Oct 2012. CZUT-IC 11547 (8, 35.9 – 45.7 mm SL); Natagaima, río Anchique, 03 ° 35 ’ 10 ” N 75 ° 07 ’ 54 ” W; J. G. Albornoz-Garzón, D. Montoya, F. A. Villa Navarro, 7 Feb 2014. IAvH-P 4603 (3, 43.4 – 47.9 mm SL); Coello, quebrada Gualanday, tributary of río Coello, 04 ° 18 ’ 17.5 ” N 75 ° 02 ’ 0.01 ” W; F. A. Villa-Navarro, L. J. García-Melo, J. A. Maldonado-Ocampo, P. A. Buckup, 21 Apr 2005. IAvH-P 13684 (1, 34.5 mm SL); San Sebastián de Mariquita, río Cuamo, tributary of río Sabandija, 05 ° 08 ’ 34.5 ” N 74 ° 53 ’ 58.9 ” W, 438 m a. s. l.; L. M. Mesa-Salazar & P. Sánchez-Duarte, 17 Oct 2015.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE507FF932FA8F90DFC44F945.taxon	diagnosis	Diagnosis: Magdalenichthys poira is distinguished from all its congeners by the number of vertebrae (38 – 39 vs. 36 – 37 in M. lundbergi, 32 – 33 in M. mompox, 40 in M. yariguies). Magdalenichthys poira can be separated from M. lundbergi and M. yariguies by having modally more branched rays in the upper lobe of the caudal fin (seven vs. six). Magdalenichthys poira differs from M. mompox and M. yariguies by the number of gill rakers on first arch (5 – 6 vs. 7 – 8 in M. mompox, 3 – 4 in M. yariguies); first dorsal-fin pterygiophore inserted posterior to neural spine of vertebrae 10 – 11 (vs. vertebra 9 in M. mompox, vertebra 12 in M. yariguies); and adipose-fin origin at vertical through anal-fin origin (vs. posterior). Magdalenichthys poira further differs from M. lundbergi by having fewer rows of dentary teeth (four vs. five or more); translucent or pale nuchal band conspicuous and wide in specimens of all sizes (vs. inconspicuous and narrow in small specimens, faded or absent in large specimens); wide triangular spot at dorsal-fin origin always present in specimens of all sizes (vs. narrow transverse spot only present in specimens of 72.1 mm SL or smaller); and adipose fin hyaline (vs. dusky). Magdalenichthys poira further differs from M. mompox by having a parabolic contour of the head in dorsal view, with lateral profiles convex (vs. rectangular, with lateral profiles straight); fewer ribs (six to seven vs. eight); first anal-fin pterygiophore inserted posterior to hemal spine of vertebrae 23 – 25 (vs. vertebra 21); upper-caudal fin lobe distinctively longer than lower lobe (vs. both lobes subequal); fewer caudal-fin branched rays (13 – 14 vs. 15); more ventral procurrent caudal-fin rays (15 – 16 vs. 12 – 14); shorter head (18.4 – 22.1 % of SL vs. 22.9 – 25.1 %); wider mouth (41.3 – 53.5 % of HL vs. 28.7 – 36.3 %); shorter maxillary barbel (17.5 – 23 % of HL vs. 22.8 – 32.1 %); and shorter inner mental barbel (8.4 – 12.9 % of HL vs. 12.5 – 15.8 %). Magdalenichthys poira differs from M. yariguies by having fewer branched pectoral-fin rays (seven vs. eight); fewer principal (segmented) anal-fin rays (9 – 10 vs. 11 – 12); fewer anal-fin pterygiophores (9 – 10 vs. 11); last anal-fin pterygiophore anterior to hemal spine of vertebra 30 (vs. vertebrae 33 – 34); more dorsal procurrent caudal-fin rays (14 – 16 vs. 13); more ventral procurrent caudal-fin rays (15 – 16 vs. 13 – 14); wider mouth (41.3 – 53.5 % of HL vs. 35.4 – 41.8 %); and larger eye (11.9 – 17.8 % of HL vs. 7.0 – 11.7 %).	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE507FF932FA8F90DFC44F945.taxon	description	Description: Morphometric data in Table 1. Refer to Figure 7 for general appearance. Small heptapterine catfish (largest specimen 71.4 mm SL), with elongated body, elliptical in cross-section at dorsal-fin origin, progressively more compressed to caudal region. Dorsal profile straight from snout tip to occipital region, slightly convex immediately posterior from this point to dorsal-fin origin, then straight to adipose-fin origin, gently sloping ventrally to posterior end of adipose-fin base, and slightly ascending along caudal peduncle. Ventral profile of head slightly convex, straight along abdomen to anal-fin origin, ascending along anal-fin base and slightly descending along caudal peduncle. Head depressed, parabolic in dorsal view, dorsally covered by thin skin. Cheek filled with muscular mass of adductor mandibulae, but muscle not reaching dorsally onto skull roof. Snout short and rounded. Mouth slightly prognathous. Premaxillary teeth arranged in a rhomboidal patch of 4 (2) – 5 (1) * medial and eight lateral irregular rows of minute conical teeth. Lower jaw slightly longer than upper jaw. Dentary teeth in four irregular rows of minute conical teeth, similar to those on premaxilla. Maxillary barbel reaching pectoral-fin axil. Conspicuous groove accommodating anterior part of maxillary barbel along sides of head, delimiting dorsal and lateral regions of head. Bases of outer and inner mental barbels in a straight line. Mental barbels not reaching base of pectoral fin. Outer mental barbel reaching branchiostegal membrane. Small subcutaneous eye, dorsal in position and slightly longer horizontally. Anterior naris tubular. Posterior naris closer to anterior margin of eye than to anterior naris, anteriorly bordered by a low fleshy margin. Anterior and posterior internarial widths equal. Nares disposed in a squared arrangement. Branchiostegal membrane free, supported by eight rays and joined to isthmus only at anteriormost point. Gill rakers of first arch 5 – 6, located along anterior margin of ceratobranchial. Lateral line canal complete, reaching caudal skeleton. Supraorbital pore s 1 medially adjacent to anterior naris; s 2 + i 2 pore slightly closer to anterior naris (Fig. 8), at distal end of posteriorly directed membranous tubule, originating from commissure connecting supraorbital and infraorbital canals, closer to infraorbital canal; s 3 pore not visible externally, inside posterior naris, adjacent to its posterior margin, at notch of cutaneous membrane. Contralateral supraorbital canals connected medially by epiphyseal membranous branch, dorsal to anterior fontanel, without superficial pore; s 8 pore (parietal branch) arising from a posteriorly directed membranous canal, externally located posterior to eye, at level of medial margin of eye; s 4 and s 7 branches and pores absent. Infraorbital pore i 1 laterally adjacent to anterior naris, between naris and maxillary barbel base; i 3 pore posterior to maxillary barbel base; i 4 pore at vertical through anterior margin of eye; i 5 pore ventral to posterior region of eye; i 6 pore at vertical through posterior margin of eye. Pterotic branch (po 2) at posterolateral corner of pterotic. Dentary with seven pores of preoperculo-mandibular canal. Submental pores (pm 1) paired. Sixth and seventh mandibular pores approximately at same vertical level, and seventh pore just anterior to lateral articulation between dentary and anguloarticular bones. Subpreopercular ossicle with one pore (pm 8). Preopercle with two pores, anterior pore (pm 9) originating from membranous tubule lateral to interopercle and posterior pore (pm 10) from membranous tubule passing lateral to ventral portion of opercle. Last preopercular pore (po 1 + pm 11) at end of membranous tubule, dorsal to dorsoposterior portion of opercle. Axillary branch (ll 1) ventral, running posterior to supracleithrum. Precaudal vertebrae 10 (1) – 11 (2), thoracic vertebrae 8 (1) or 9 (2), and caudal vertebrae 28, totalling 38 – 39 vertebrae. Ribs six or seven. Pectoral fin with i, 6 (2), 7 * (34), or 8 (23) rays. First pectoral-fin ray (unbranched) soft and shorter than first branched ray. First branched ray longest. Distal margin of pectoral fin convex. Pelvic fin with i, 5 rays. First pelvic-fin ray (unbranched) thick and shortest, second and third branched rays longest. Pelvic-fin origin opposite to dorsal-fin origin, at vertical through vertebra 14 (2). Dorsal fin lacking spinelet, with one unbranched and six branched rays, supported by seven pterygiophores. Dorsal-fin margin convex, its unbranched ray slightly shorter than first branched ray; first three branched rays subequal. First dorsal-fin pterygiophore inserted posterior to neural spine of vertebrae 10 (1) or 11 (2) and last pterygiophore anterior to neural spine of vertebra 16. Adipose fin long, almost rectangular with attenuated ends and posterior lobe free. Adipose-fin origin at vertical through anal-fin origin. Anal fin with two procurrent (unsegmented) rays, and two * (24), three (1), or four (1) unbranched and six (2), seven (19), or eight (5) * branched rays, for a total of nine (20) or ten * (5) principal rays. Posteriormost ray (branched) individually associated to last pterygiophore. Anal fin supported by 9 (2) – 10 (1) pterygiophores. First anal-fin pterygiophore posterior to hemal spine of vertebrae 23 (1) or 25 (2) and last pterygiophore anterior to hemal spine of vertebra 30. Caudal fin deeply forked with i, 7 + 7, i principal rays (one single specimen out of 23 with six branched rays in upper lobe). Upper lobe of caudal fin distinctly longer than lower lobe, both lobes generally rounded. Procurrent caudal-fin rays 14 (2) – 16 (1) dorsal and 15 (2) – 16 (1) ventral, located posterior to vertebra PU 6. Posteriormost one (1) or two (2) dorsal and three or four ventral procurrent caudal-fin rays segmented. Caudal skeleton PH + 1 + 2,3 + 4 + 5. Long epural present. Pigmentation in alcohol: Overall ground coloration light brown. Minute and numerous melanophores clustered at humeral region, forming posteriorly a midlateral stripe extending to caudal-fin base. Dark streak extending dorsally on surface of snout, between base of maxillary barbel and anterior margin of eye. Conspicuous and wide pale band at posterior margin of head, between dorsal corners of branchial openings. Pale triangular spot at dorsal-fin origin. Pale spot at adipose-fin origin variably present. Cheeks lighter than remaining surface of head. Basal portion of maxillary barbel with chromatophores on dorsal surface. Base of dorsal fin with a dark band along sides. Base of caudal fin with denser vertical cluster of chromatophores. Ventral surface of head and body pale. Interradial membrane of fins and adipose fin hyaline.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE507FF932FA8F90DFC44F945.taxon	distribution	Distribution: This species is present in the Anchique, Prado, Saldaña, Coello, Totare, and Sabandija rivers, all direct tributaries of the upper Magdalena River basin (Fig. 4).	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE507FF932FA8F90DFC44F945.taxon	biology_ecology	Habitat and ecological notes: Magdalenichthys poira is found in small streams of 0.1 – 2 m depth, substrate of sand, pebbles, and rocks, moderate current, and margins with riparian vegetation. Main food items found in dissected specimens for clearing and staining were Chironomidae, Hydropsychidae, and Ephemeroptera. This species is found syntopically in the Alvarado River with Cetopsorhamdia molinae, Pimelodella floridablancaensis ArdilaRodríguez, 2017, Rhamdia guatemalensis (Günther, 1864), Pimelodus yuma Villa-Navarro & Acero P., 2017, Trichomycterus banneaui (Eigenmann, 1912), Trichomycterus mogotensis Ardila Rodríguez, 2017, Trichomycterus transandianus (Steindachner, 1915), Chaetostoma milesi Fowler, 1941, Chaetostoma thomsoni Regan, 1904, Lasiancistrus volcanensis Dahl, 1942, Sturisomatichthys leightoni (Regan, 1912), Astroblepus marmoratus (Regan, 1904), Astroblepus homodon (Regan, 1904), Sternopygus aequilabiatus (Humboldt, 1805), Apteronotus eschmeyeri de Santana, Maldonado-Ocampo, Severi & Mendez, 2004, Cynodonichthys magdalenae (Eigenmann & Henn, 1916), Poecilia reticulata Peters, 1859, Poecilia sphenops Valenciennes, 1846, Andinoacara latifrons (Steindachner, 1878), Geophagus steindachneri Eigenmann & Hildebrand, 1910, and Kronoheros umbrifer (Meek & Hildebrand, 1913) (Albornoz-Garzón et al. 2020).	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE507FF932FA8F90DFC44F945.taxon	etymology	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.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE51AFF972CB7F905FEB2FB40.taxon	description	(Figs 9 – 10; Table 1) ZooBank registration: urn: lsid: zoobank. org: act: EF 13 BC 97 - 59 E 8 - 4388 - 82 E 5 - 58 E 0 F 825927 E.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE51AFF972CB7F905FEB2FB40.taxon	materials_examined	Holotype: IAvH-P 22481 (67.9 mm SL), Colombia, Santander, El Carmen de Chucurí, quebrada La Concordia, río La Colorada drainage, 06 ° 34 ’ 55.2 ” N 73 ° 35 ’ 36 ” W, 683 m a. s. l.; J. G. Albornoz-Garzón, A. Suárez-Gamboa & G. Caballero, 24 Feb 2018. Paratypes: Santander: El Carmen de Chucurí: IAvH-P 17732 (1, 41.9 mm SL, 1 c & s, 46.8 mm SL); same locality and collectors as holotype, 22 Feb 2018. IAvH-P 17744 (2, 40.3 – 45.8 mm SL, 1 c & s, 53.3 mm SL); same locality and collectors as holotype, 23 Feb 2018. IAvH-P 17757 (1, 62 mm SL); collected with holotype. IAvH-P 17769 (1, 53.5 mm SL); quebrada La Concordia, río La Colorada drainage, 06 ° 35 ’ 17.7 ” N 73 ° 35 ’ 04.8 ” W, 672 m a. s. l.; J. G. Albornoz-Garzón & G. Caballero, 25 Feb 2018. IAvH-P 17792 (1, 60.6 mm SL); quebrada La Leona, río La Colorada drainage, 06 ° 34 ’ 35.7 ” N 73 ° 34 ’ 30.7 ” W, 713 m a. s. l.; J. G. Albornoz-Garzón, 26 Feb 2018.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE51AFF972CB7F905FEB2FB40.taxon	diagnosis	Diagnosis: Magdalenichthys yariguies can be distinguished from all its congeners by having 40 vertebrae (vs. 36 – 37 in M. lundbergi, 32 – 33 in M. mompox, 38 – 39 in M. poira); more principal (segmented) anal-fin rays (11 – 12 vs. 9 – 10); and last anal-fin pterygiophore anterior to hemal spine of vertebrae 33 – 34 (vs. 29 – 30 in M. lundbergi, 30 in M. poira, 27 in M. mompox). Magdalenichthys yariguies is distinguished from M. lundbergi and M. mompox by having a longer anal-fin base (15.6 – 18.1 % of SL vs. 11.7 – 14.4 % in M. lundbergi, 9.9 – 13.5 % in M. mompox). Magdalenichthys yariguies is distinguished from M. lundbergi and M. poira by having the adipose-fin origin posterior to the anal-fin origin (vs. at same vertical). Magdalenichthys yariguies is distinguished from M. mompox and M. poira by number of gill rakers on first arch (3 – 4 vs. 7 – 8 in M. mompox, 5 – 6 in M. poira); first dorsal-fin pterygiophore inserted posterior to neural spine of vertebra 12 (vs. vertebra 9 in M. mompox, vertebrae 10 – 11 in M. poira); more anal-fin pterygiophores (11 vs. 9 – 10); and fewer branched rays in the upper lobe of the caudal fin (six vs. seven). Magdalenichthys yariguies further differs from M. lundbergi by having fewer rows of dentary teeth (four vs. five or more); shorter caudal peduncle (16.3 – 19.3 % of SL vs. 20.1 – 24.2 %); and longer maxillary barbel (24.2 – 30.9 % of HL vs. 17.5 – 23 %). Magdalenichthys yariguies further differs from M. mompox by having a parabolic contour of the head in dorsal view, with lateral profiles convex (vs. rectangular, with lateral profiles straight); first anal-fin pterygiophore inserted posterior to hemal spine of vertebrae 24 – 25 (vs. vertebra 21); upper-caudal fin lobe distinctively longer than lower lobe (vs. both lobes subequal); fewer caudal-fin branched rays (13 or fewer vs. 15); narrower cleithral width (12.8 – 15.2 % of SL vs. 15.3 – 19.1 %); longer adipose-fin base (26.2 – 28.9 % of SL vs. 17.5 – 20.9 %); shorter prepelvic distance (35.4 – 41.5 % of SL vs. 42 – 47.9 %); shorter caudal-fin lower lobe (16.3 – 19.4 % of SL vs. 21.9 – 24.9 %); and shorter head (16.7 – 20.4 % of SL vs. 22.9 – 25.1 %). Magdalenichthys yariguies further differs from M. poira by having more branched pectoral-fin rays (eight vs. seven); fewer dorsal procurrent caudal-fin rays (13 vs. 14 – 16); fewer ventral procurrent caudal-fin rays (13 – 14 vs. 15 – 16); smaller eye (7.0 – 11.7 % of HL vs. 11.9 – 17.8 %); and narrower mouth (35.4 – 41.8 % of HL vs. 41.3 – 53.5 %).	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE51AFF972CB7F905FEB2FB40.taxon	description	Description: Morphometric data in Table 1. Refer to Figure 9 for general appearance. Small heptapterine catfish (largest specimen 67.9 mm SL), with elongated body, elliptical in cross-section at dorsal-fin origin (longest axis horizontal), progressively more compressed to caudal region. Dorsal profile slightly convex from snout tip to occipital region, straight immediately posterior from this point to adipose-fin origin, sloping ventrally along adipose-fin base, and slightly ascending along dorsal membrane supported by procurrent caudal-fin rays. Ventral profile of head slightly convex, then straight to pelvic-fin insertion, slightly concave from this point to anal-fin origin, ascending along anal-fin base to origin of procurrent caudal-fin rays and slightly descending along ventral membrane supported by procurrent caudal-fin rays. Head depressed, parabolic in dorsal view, dorsally covered by thin skin. Cheek filled with muscular mass of adductor mandibulae, but muscle not reaching dorsally onto skull roof. Snout short and rounded. Mouth slightly prognathous. Premaxillary teeth arranged in a rhomboidal patch of 4 – 5 * medial and eight lateral irregular rows of minute conical teeth. Lower jaw slightly longer than upper jaw. Dentary teeth arranged in four irregular rows of minute conical teeth, similar to those on premaxilla. Maxillary barbel reaching distal tip of innermost pectoral-fin ray. Conspicuous groove accommodating anterior part of maxillary barbel along sides of head, delimiting dorsal and lateral regions of head. Bases of outer and inner mental barbels in a straight line. Outer mental barbel reaching pectoral-fin base. Inner mental barbel surpassing branchial opening. Subcutaneous eye small, dorsal in position and slightly longer in horizontal than vertical axis. Anterior naris tubular. Posterior naris closer to anterior margin of eye than to anterior naris, anteriorly bordered by a low fleshy margin. Anterior and posterior internarial widths equal. Nares disposed in a squared arrangement. Branchiostegal membrane free, supported by eight rays and joined to isthmus only at anteriormost point. Gill rakers on first arch 3 – 4, located along anterior margin of ceratobranchial. Lateral line canal complete, reaching caudal skeleton. Supraorbital pore s 1 medially adjacent to anterior naris; s 2 + i 2 pore slightly closer to anterior naris (Fig. 10), at end of posteriorly directed membranous tubule, originating from commissure connecting supraorbital and infraorbital canals, closer to supraorbital canal; s 3 pore inside posterior naris, adjacent to its posterior margin, at notch of cutaneous membrane. Contralateral supraorbital canals connected medially by epiphyseal membranous branch, dorsal to middle of anterior fontanel, without superficial pore; s 8 pore (parietal branch) arising from a posteriorly directed membranous canal, externally located posterior to eye, at level of medial margin of eye; s 4 and s 7 branches and pores absent. Infraorbital pore i 1 laterally adjacent to anterior naris, between naris and maxillary barbel base; i 3 pore posterior to maxillary barbel base; i 4 pore at vertical through anterior margin of eye; i 5 pore behind vertical through posterior margin of eye; i 6 pore posterior to eye, aligned with ventral margin of eye. Pterotic branch (po 2) at posterolateral corner of pterotic. Dentary with seven pores of preoperculo-mandibular canal. Submental pores (pm 1) paired. Sixth and seventh mandibular pores approximately at same vertical level. Subpreopercular ossicle with one pore (pm 8). Preopercle with two pores, anterior pore (pm 9) originating from membranous tubule lateral to interopercle and posterior pore (pm 10) from membranous tubule passing lateral to ventral portion of opercle. Last preopercular pore (po 1 + pm 11) at end of membranous tubule, dorsal to dorsoposterior portion of opercle. Axillary branch (ll 1) ventral, running posterior to supracleithrum. Precaudal vertebrae 11 (1) – 12 (1), thoracic vertebrae 9, and caudal vertebrae 28 (1) – 29 (1), totalling 40 vertebrae. Ribs seven or eight (last pair shortest). Pectoral fin with i, 8 rays. First pectoral-fin ray (unbranched) soft and shorter than first branched ray. First branched ray longest. Distal margin of pectoral fin convex. Pelvic fin with i, 5 rays. First pelvic-fin ray (unbranched) thick and shortest, second and third branched rays longest. Pelvic-fin origin opposite to dorsal-fin origin, at vertical through vertebra 14 or 15. Dorsal fin lacking spinelet, with one unbranched and six branched rays, supported by seven pterygiophores. Dorsal-fin margin convex, its unbranched ray slightly shorter than first branched ray; first three branched rays subequal. First dorsal-fin pterygiophore inserted posterior to neural spine of vertebra 12 and last pterygiophore anterior to neural spine of vertebra 17. Adipose fin long, almost rectangular with attenuated ends and posterior lobe free. Adipose-fin origin at vertical through second unbranched ray of anal fin. Anal fin with 2 – 3 procurrent (unsegmented) rays, and 3 * (5) – 4 (2) unbranched and 8 * (6) – 9 (2) branched rays for a total of 11 (5) or 12 (3) principal rays. Anal-fin distal margin rounded. Anal fin supported by 11 pterygiophores. First anal-fin pterygiophore posterior to hemal spine of vertebrae 24 (1) – 25 (1) and last pterygiophore anterior to hemal spine of vertebrae 33 (1) – 34 (1). Caudal fin deeply forked with i, 6 + 7, i * principal rays (one c & s specimen with six branched rays in the lower lobe). Upper lobe of caudal fin conspicuously longer than lower lobe, both lobes pointed. Procurrent caudal-fin rays 13 dorsal and 13 – 14 ventral, located posterior to vertebrae PU 6. Posteriormost four procurrent caudal-fin rays segmented. Caudal skeleton PH + 1 + 2,3 + 4 + 5. Long epural present. Pigmentation in alcohol: Overall ground coloration marbled. Minute and numerous melanophores clustered at humeral region, forming posteriorly a midlateral inconspicuous stripe extending to caudal-fin base. Myosepta delineated by chromatophores, more evident above anal-fin base. Dorsal surface of head and predorsal area darker than remaining surface of body. Dark streak extending dorsally on surface of snout, between base of maxillary barbel and anterior margin of eye. Conspicuous and narrow pale band with roughly M-shaped, posterior to head, between dorsal corners of branchial openings. Cheeks and maxillary groove lighter than remaining surface of head, peppered with sparse chromatophores. Basal portion of maxillary barbel darkly pigmented on dorsal surface. Base of dorsal fin with a dark band along sides. Ventral surface of head with anterior crescent shaped dusky area fading posteriorly, isthmus and branquiostegal membrane pale. Abdomen pale, sparse chromatophores posterior to ventral fins. Adipose fin with marbled pattern of chromatophores. Dorsal-fin rays with chromatophores. Basal portion of pectoral and pelvic-fin rays with chromatophores. Base of anal-fin rays with chromatophores. Caudal-fin rays with minute chromatophores, giving diffuse dark pigmentation. Interradial membrane of fins hyaline.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE51AFF972CB7F905FEB2FB40.taxon	distribution	Distribution: This species is restricted to the La Colorada River drainage, a direct tributary of the middle section of the Magdalena River basin (Fig. 4).	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE51AFF972CB7F905FEB2FB40.taxon	biology_ecology	Habitat and ecological notes: The type locality of Magdalenichthys yariguies is a stream with an average width of 7 m, substrate of sand, pebbles, and rocks, and margins with abundant riparian vegetation (Fig. 11). Specimens of M. yariguies were found syntopically with Hoplias malabaricus (Bloch, 1794), Lebiasina floridablancaensis Ardila Rodríguez, 2001, Astyanax yariguies (Torres-Mejia, Hernández & Senechal, 2012), Creagrutus guanes Torres-Mejia & Vari, 2005, Creagrutus magdalenae Eigenmann, 1913, Hemibrycon plutarcoi (Román-Valencia, 2001), Hemibrycon sp., Knodus sp., Trichomycterus calai Ardila Rodríguez, 2019, Trichomycterus cf. transandianus (Steindachner, 1915), Trichomycterus sp., Astroblepus cf. verai Ardila Rodríguez, 2015, Farlowella yarigui Ballen & Mojica, 2014, Dolichancistrus carnegiei (Eigenmann, 1916), Lasiancistrus volcanensis Dahl, 1941, Pimelodella floridablancaensis, Poecilia caucana (Steindachner, 1880), and Geophagus steindachneri.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
EB5CB23FE51AFF972CB7F905FEB2FB40.taxon	etymology	Etymology: The name yariguies honours the exterminated indigenous group that inhabited the río Cascajales drainage. Used as a noun in apposition.	en	DoNascimiento, Carlos, Villa-Navarro, Francisco Antonio, Albornoz-Garzón, Juan G., Conde-Saldaña, Cristhian C., Silva, Gabriel S. C., Méndez-López, Alejandro, Roxo, Fábio F., Ortega-Lara, Armando, Oliveira, Claudio (2025): An unexpectedly diverse new genus of catfishes (Siluriformes, Heptapteridae) endemic to the Magdalena River basin, Colombia. Zoological Journal of the Linnean Society 204: 1-30, DOI: 10.1093/zoolinnean/zlaf048
