Imparfinis, Eigenmann & Norris, 1900

Ortega-Lara, Armando, Milani, Nadia, DoNascimiento, Carlos, Villa-Navarro, Francisco & Maldonado-Ocampo, Javier Alejandro, 2011, Two new trans-Andean species of Imparfinis Eigenmann & Norris, 1900 (Siluriformes: Heptapteridae) from Colombia, Neotropical Ichthyology 9 (4), pp. 777-793 : 790-791

Key to the trans-Andean and Central-American species of Imparfinis

1. Maxillary barbels reaching to or exceeding pelvic-fin origin ....................................................................................... 2

1’. Maxillary barbels not reaching pelvic-fin origin ................ 4

2. First ray of dorsal fin longer than second ray; maxillary barbel surpassing pelvic-fin base ....................................... 3

2’. First ray of dorsal fin shorter than second ray; maxillary barbel reaching pelvic-fin origin (reaching anal-fin origin in some juvenile specimens) ......................... I. timana ( Figs. 1 , 5g ; río Guarapas , upper río Magdalena basin)

3. First ray of dorsal fin projecting beyond fin margin as a long filament (length of first dorsal-fin ray: 29.2-33.1% in SL); pectoral fin surpassing pelvic-fin origin; lower caudal-fin lobe pointed, with lower branch of lowermost branched ray longer than upper branch, and extended as a filament ............... ............................................ I. nemacheir ( Figs. 5 b-d; río Atrato , río Magdalena and lago de Maracaibo basins)

3’. First ray of dorsal fin not projected as a long filament (length of first dorsal-fin ray: 19.1-23.2% in SL); pectoral fin not reaching pelvic-fin origin; lower caudal-fin lobe rounded in specimens longer than 30 mm SL, with both branches of lowermost branched ray approximately equal in length .................................................................. I. usmai ( Figs. 3 , 4 , 5a ; río Patía , río Cauca and río Magdalena basins)

4. Maxillary barbel extending to half the length of pectoral fin, adipose-fin length: 17.2-18.6% in SL ................. I. lineatus ( Fig. 5h ; streams in Pacific versant of northern Costa Rica)

4’. Maxillary barbel extending to end of pectoral fin, adiposefin length:21.1-22.9% in SL .................................... I. spurrellii ( Fig. 5e ; río San Juan basin)

Figures

Fig. 1. Imparfinis timana, holotype, IAvH-P 10696, 74.2 mm SL, Colombia, Huila, Palestina, río Guarapas, in the mouth of quebrada La Quebradona, upper río Magdalena basin, 01º45’49”N 76º05’05”W. Scale bar = 1 cm.

Fig. 5. Trans-Andean species of Imparfinis and I. pseudonemacheir from Venezuelan Orinoco basin. Scale bars 1 cm. (a) I. usmai, MBUCV-V-35640, 88.7 mm SL, Colombia, Valle del Cauca, Cartago, río La Vieja,Valle Cartago, upper río Cauca basin; (b) I. nemacheir, FMNH 58127 (ex CM 7125), 105.0 mm SL, holotype of Nannorhamdia nemacheir, photograph by M. Littmann, FMNH Division of Fishes; (c) I. nemacheir, holotype of N. nemacheir, illustration from Eigenmann (1922); (d) I. nemacheir, MHNLS 15453, 81.4 mm SL, Venezuela, Trujillo, río Pocó, Lago de Maracaibo basin; (e) I. spurrellii, ICN-MHN 5532, 82.0 mm SL, Colombia, Chocó, río San Juan; (f) I. pseudonemacheir,MBUCV-V-28656, 48.1 mm SL, Venezuela,Anzoategui, ríoAtapirire, where crossed by the road between Manasma and Atipirire, río Orinoco basin; (g) I. timana, IAvH-P 10696, 74.2 mm SL, holotype, Colombia, Huila, río Guarapas, in the mouth of quebrada La Quebradona, río Magdalena basin; (h) I. lineatus, MBUCV-V-32675, 69.4 mm SL, Costa Rica, Puntarenas, río Peje, 13 km S of San Isidro General.

Fig. 3. Imparfinis usmai, holotype, IMCN 4812, 83.4 mm SL, Colombia, Departamento del Tolima, Municipio Coello, vereda Potrerillo, quebrada Potrerilla, tributary of río Coello, río Magdalena basin, 04°16’57.9”N 75°01’53.8”W. Scale bar = 1 cm.

Fig. 4. Imparfinis usmai, live specimen (IMCN 3842, 73.6 mm SL), Colombia, Cauca, Caloto, río Japio, upper río Cauca basin, 03°01’N76°24’W.