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

Magdalenichthys poira Villa-Navarro, DoNascimiento, Albornoz-Garzón, Méndez-López & Conde-Saldaña sp. nov.

( Figs 7–8 View Figure 7 View Figure 8 ; Table 1 View Table 1 )

ZooBank registration: urn:lsid:zoobank.org:act:8FDB875FDB8E-42AD-A6FF-757D086E0121.

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. GoogleMaps

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 GoogleMaps . 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 GoogleMaps . 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 GoogleMaps . 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 GoogleMaps . CZUT-IC 3176 ( 9, 24.2–62.9 mm SL); collected with holotype. GoogleMaps 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 GoogleMaps . 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 GoogleMaps . 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 GoogleMaps . 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 GoogleMaps . 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 GoogleMaps .

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%).

Description: Morphometric data in Table 1 View Table 1 . Refer to Figure 7 View 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 s1 medially adjacent to anterior naris; s2 + i2 pore slightly closer to anterior naris ( Fig. 8 View Figure 8 ), at distal end of posteriorly directed membranous tubule, originating from commissure connecting supraorbital and infraorbital canals, closer to infraorbital canal; s3 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; s8 pore (parietal branch) arising from a posteriorly directed membranous canal, externally located posterior to eye, at level of medial margin of eye; s4 and s7 branches and pores absent. Infraorbital pore i1 laterally adjacent to anterior naris, between naris and maxillary barbel base; i3 pore posterior to maxillary barbel base; i4 pore at vertical through anterior margin of eye; i5 pore ventral to posterior region of eye; i6 pore at vertical through posterior margin of eye. Pterotic branch (po2) at posterolateral corner of pterotic. Dentary with seven pores of preoperculo-mandibular canal. Submental pores (pm1) 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 (pm8). Preopercle with two pores, anterior pore (pm9) originating from membranous tubule lateral to interopercle and posterior pore (pm10) from membranous tubule passing lateral to ventral portion of opercle. Last preopercular pore (po1 + pm11) at end of membranous tubule, dorsal to dorsoposterior portion of opercle. Axillary branch (ll1) 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.

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 View Figure 4 ).

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) .

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.