Fig 1.
Corydoras undulatus, holotype.
BMNH 1912.7.10.5, 43.9 mm SL, “La Plata” locality. Donor Dr. Willy Georg Wolterstorff. Dorsal, lateral and ventral view. “The Trustees of the Natural History Museum, London”. (Photograph and credit by Mark Allen, All Catfish Species Project).
Fig 2.
Corydoras undulatus, paratypes.
BMNH 1909.9.28.3–4, 26.7 mm SL and 27.8 mm SL, “La Plata” locality. Donated by Johann Paul Arnold. Dorsal, lateral and ventral view. “The Trustees of the Natural History Museum, London”. (Photograph and credit by Mark Allen, All Catfish Species Project).
Fig 3.
IBIGEO-I 451, 37.4 mm SL, from San Lorenzo stream, Paraná River basin, at Entre Ríos Province in Argentina. Dorsal, lateral and ventral view.
Table 1.
Morphometric data of the holotype and 157 non-type specimens of Corydoras undulatus.
Fig 4.
MCP 46587 (29.1 mm SL), left lateral view. Abbreviations: cpt = compound-pterotic, f = frontal, io1 = infraorbital 1, io2 = infraorbital 2, op = opercle, pso = parieto-supraoccipital, sph = sphenotic. Scale bars = 1.0 mm.
Fig 5.
UNICTIO 2600, 28.3 mm SL: (A) suspensorium and operculum of Corydoras undulatus. Lateral view. Abbreviations: aa = angle-articular, d = dentary, hym = hiomandibula, iop = interoperate, mp = metapterigoid, op = opercle, pop = preopercle, q = quadrate; (B) pectoral girdle of Corydoras undulatus. Ventral view. bpr = pectoral-fin ray, cl = cleithrum, fab = fossa of the abductor muscles of pectoral fin, pecs = pectoral-fin spine, pr = pectoral radials, sco = scapulocoracoid; (C) caudal-fin skeleton of Corydoras undulatus. Lateral view. ccc = compound ural centrum, cfr = principal rays, epu = epural, has = haemal spine, hyp = hypurals and parhypural, hypu = hypurals and uroneural, nes = neural spine, pcr = procurrent rays, ph = parhypural, pu2-3 = preural centrum. Scale bars = 1.0 mm.
Fig 6.
Color in life of Corydoras undulatus in left lateral view.
(A) IBIGEO-I 452, 43.1 mm SL, Yapeyu (29°28'14.30"S 56°48'59.41"W). (B) MHNM 4000, 32.5 mm SL, Rincón de Franquia, Bella Unión, Artigas, Uruguay (30°11'45.75"S 57°37'8.40"W), (Photograph: Wilson Sebastián Serra Alanis); (C) IBIGEO-I 451, 37.4 mm SL, San Lorenzo stream, Paraná River basin, at Entre Ríos Province in Argentina (Photograph: Roberto Toval).
Fig 7.
Ontogenetic variation of color pattern of Corydoras undulatus.
Left lateral view. (A) male, approx. 40 mm TL; (B) female, approx. 45 mm TL; (C) eggs adhered to submerged vegetation, about 1.5 mm in diameter; (D) 7 days post hatching (PH), approx. 7 mm TL; (E) 2 weeks PH, approx. 11 mm TL; (F) 4 weeks, approx. 15 mm TL; (G) 3 months, approx. 24 mm TL. (Photograph: Hans Evers).
Fig 8.
Photo of preserved specimens of Corydoras undulatus.
IBIGEO-I 452, 43.1 mm SL, Yapeyu (29°28'14.30"S 56°48'59.41"W): (A) male in lateral view; (B) female in lateral view; (C) pelvic fin and urogenital papillae of male in ventral view; (D) pelvic fin and urogenital papillae of female in ventral view.
Fig 9.
Map with the geographical distribution of Corydoras undulatus.
Each symbol (red circles) may represent more than one locality.
Fig 10.
Principal Component Analysis (PCA).
Plots of factor scores of principal component analysis of three populations of Corydoras undulatus. Square from río Paraná basin; circle from Uruguay basin; cross from Laguna dos Patos basin.
Fig 11.
Habitat of Corydoras unduluatus.
(A) Near Yapeyú, Corrientes, Argentina where this species is particularly abundant in habitats with low water flow and abundant aquatic macrophytes. (B) Corydoras undulatus capture site in San Lorenzo stream, affluent of Paraná River, Province of Entre Ríos, Argentina, (32°48'2.28"S 60° 29'56.63"W) (Photograph: Roberto Toval).
Fig 12.
CAS 36452 [ex IU 17278], 41.5 mm SL, Lago Rojo Agua, Río Beni basin, Upper Amazon system, Beni, Bolivia. coll. N. E. Pearson, 1921. Lateral, dorsal and ventral view.
Fig 13.
Corydoras bilineatus, paratype.
ZMB 33297, 45.3 mm SL, Chené, Santiesteban, Santa Cruz Dept., Bolivia. coll. J. Knaack, 2001. Lateral, dorsal and ventral view. Scale bars = 10 mm. (Photograph and credit by Edda Aβel, Museum für Naturkunde Berlin).